Mercurial > hg > graal-jvmci-8
annotate src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp @ 14466:d166675568f6
8034761: Remove the do_code_roots parameter from process_strong_roots
Reviewed-by: tschatzl, mgerdin, jmasa
author | stefank |
---|---|
date | Thu, 13 Feb 2014 17:44:39 +0100 |
parents | e5d78f318aec |
children | 4ca6dc0799b6 |
rev | line source |
---|---|
0 | 1 /* |
7623
203f64878aab
7102489: RFE: cleanup jlong typedef on __APPLE__and _LLP64 systems.
hseigel
parents:
6885
diff
changeset
|
2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. |
0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
1552
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1521
diff
changeset
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1521
diff
changeset
|
20 * or visit www.oracle.com if you need additional information or have any |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1521
diff
changeset
|
21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
26 #include "classfile/classLoaderData.hpp" |
1972 | 27 #include "classfile/symbolTable.hpp" |
28 #include "classfile/systemDictionary.hpp" | |
29 #include "code/codeCache.hpp" | |
30 #include "gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp" | |
31 #include "gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp" | |
32 #include "gc_implementation/concurrentMarkSweep/cmsGCAdaptivePolicyCounters.hpp" | |
33 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp" | |
34 #include "gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp" | |
35 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.inline.hpp" | |
36 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp" | |
37 #include "gc_implementation/concurrentMarkSweep/vmCMSOperations.hpp" | |
38 #include "gc_implementation/parNew/parNewGeneration.hpp" | |
39 #include "gc_implementation/shared/collectorCounters.hpp" | |
10405 | 40 #include "gc_implementation/shared/gcTimer.hpp" |
41 #include "gc_implementation/shared/gcTrace.hpp" | |
42 #include "gc_implementation/shared/gcTraceTime.hpp" | |
1972 | 43 #include "gc_implementation/shared/isGCActiveMark.hpp" |
44 #include "gc_interface/collectedHeap.inline.hpp" | |
10405 | 45 #include "memory/allocation.hpp" |
1972 | 46 #include "memory/cardTableRS.hpp" |
47 #include "memory/collectorPolicy.hpp" | |
48 #include "memory/gcLocker.inline.hpp" | |
49 #include "memory/genCollectedHeap.hpp" | |
50 #include "memory/genMarkSweep.hpp" | |
51 #include "memory/genOopClosures.inline.hpp" | |
52 #include "memory/iterator.hpp" | |
12029
9766f73e770d
8022880: False sharing between PSPromotionManager instances
stefank
parents:
11975
diff
changeset
|
53 #include "memory/padded.hpp" |
1972 | 54 #include "memory/referencePolicy.hpp" |
55 #include "memory/resourceArea.hpp" | |
9072
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
56 #include "memory/tenuredGeneration.hpp" |
1972 | 57 #include "oops/oop.inline.hpp" |
58 #include "prims/jvmtiExport.hpp" | |
59 #include "runtime/globals_extension.hpp" | |
60 #include "runtime/handles.inline.hpp" | |
61 #include "runtime/java.hpp" | |
62 #include "runtime/vmThread.hpp" | |
63 #include "services/memoryService.hpp" | |
64 #include "services/runtimeService.hpp" | |
0 | 65 |
66 // statics | |
67 CMSCollector* ConcurrentMarkSweepGeneration::_collector = NULL; | |
10405 | 68 bool CMSCollector::_full_gc_requested = false; |
69 GCCause::Cause CMSCollector::_full_gc_cause = GCCause::_no_gc; | |
0 | 70 |
71 ////////////////////////////////////////////////////////////////// | |
72 // In support of CMS/VM thread synchronization | |
73 ////////////////////////////////////////////////////////////////// | |
74 // We split use of the CGC_lock into 2 "levels". | |
75 // The low-level locking is of the usual CGC_lock monitor. We introduce | |
76 // a higher level "token" (hereafter "CMS token") built on top of the | |
77 // low level monitor (hereafter "CGC lock"). | |
78 // The token-passing protocol gives priority to the VM thread. The | |
79 // CMS-lock doesn't provide any fairness guarantees, but clients | |
80 // should ensure that it is only held for very short, bounded | |
81 // durations. | |
82 // | |
83 // When either of the CMS thread or the VM thread is involved in | |
84 // collection operations during which it does not want the other | |
85 // thread to interfere, it obtains the CMS token. | |
86 // | |
87 // If either thread tries to get the token while the other has | |
88 // it, that thread waits. However, if the VM thread and CMS thread | |
89 // both want the token, then the VM thread gets priority while the | |
90 // CMS thread waits. This ensures, for instance, that the "concurrent" | |
91 // phases of the CMS thread's work do not block out the VM thread | |
92 // for long periods of time as the CMS thread continues to hog | |
93 // the token. (See bug 4616232). | |
94 // | |
95 // The baton-passing functions are, however, controlled by the | |
96 // flags _foregroundGCShouldWait and _foregroundGCIsActive, | |
97 // and here the low-level CMS lock, not the high level token, | |
98 // ensures mutual exclusion. | |
99 // | |
100 // Two important conditions that we have to satisfy: | |
101 // 1. if a thread does a low-level wait on the CMS lock, then it | |
102 // relinquishes the CMS token if it were holding that token | |
103 // when it acquired the low-level CMS lock. | |
104 // 2. any low-level notifications on the low-level lock | |
105 // should only be sent when a thread has relinquished the token. | |
106 // | |
107 // In the absence of either property, we'd have potential deadlock. | |
108 // | |
109 // We protect each of the CMS (concurrent and sequential) phases | |
110 // with the CMS _token_, not the CMS _lock_. | |
111 // | |
112 // The only code protected by CMS lock is the token acquisition code | |
113 // itself, see ConcurrentMarkSweepThread::[de]synchronize(), and the | |
114 // baton-passing code. | |
115 // | |
116 // Unfortunately, i couldn't come up with a good abstraction to factor and | |
117 // hide the naked CGC_lock manipulation in the baton-passing code | |
118 // further below. That's something we should try to do. Also, the proof | |
119 // of correctness of this 2-level locking scheme is far from obvious, | |
14309 | 120 // and potentially quite slippery. We have an uneasy suspicion, for instance, |
0 | 121 // that there may be a theoretical possibility of delay/starvation in the |
122 // low-level lock/wait/notify scheme used for the baton-passing because of | |
14309 | 123 // potential interference with the priority scheme embodied in the |
0 | 124 // CMS-token-passing protocol. See related comments at a CGC_lock->wait() |
125 // invocation further below and marked with "XXX 20011219YSR". | |
126 // Indeed, as we note elsewhere, this may become yet more slippery | |
127 // in the presence of multiple CMS and/or multiple VM threads. XXX | |
128 | |
129 class CMSTokenSync: public StackObj { | |
130 private: | |
131 bool _is_cms_thread; | |
132 public: | |
133 CMSTokenSync(bool is_cms_thread): | |
134 _is_cms_thread(is_cms_thread) { | |
135 assert(is_cms_thread == Thread::current()->is_ConcurrentGC_thread(), | |
136 "Incorrect argument to constructor"); | |
137 ConcurrentMarkSweepThread::synchronize(_is_cms_thread); | |
138 } | |
139 | |
140 ~CMSTokenSync() { | |
141 assert(_is_cms_thread ? | |
142 ConcurrentMarkSweepThread::cms_thread_has_cms_token() : | |
143 ConcurrentMarkSweepThread::vm_thread_has_cms_token(), | |
144 "Incorrect state"); | |
145 ConcurrentMarkSweepThread::desynchronize(_is_cms_thread); | |
146 } | |
147 }; | |
148 | |
149 // Convenience class that does a CMSTokenSync, and then acquires | |
150 // upto three locks. | |
151 class CMSTokenSyncWithLocks: public CMSTokenSync { | |
152 private: | |
153 // Note: locks are acquired in textual declaration order | |
154 // and released in the opposite order | |
155 MutexLockerEx _locker1, _locker2, _locker3; | |
156 public: | |
157 CMSTokenSyncWithLocks(bool is_cms_thread, Mutex* mutex1, | |
158 Mutex* mutex2 = NULL, Mutex* mutex3 = NULL): | |
159 CMSTokenSync(is_cms_thread), | |
160 _locker1(mutex1, Mutex::_no_safepoint_check_flag), | |
161 _locker2(mutex2, Mutex::_no_safepoint_check_flag), | |
162 _locker3(mutex3, Mutex::_no_safepoint_check_flag) | |
163 { } | |
164 }; | |
165 | |
166 | |
167 // Wrapper class to temporarily disable icms during a foreground cms collection. | |
168 class ICMSDisabler: public StackObj { | |
169 public: | |
170 // The ctor disables icms and wakes up the thread so it notices the change; | |
171 // the dtor re-enables icms. Note that the CMSCollector methods will check | |
172 // CMSIncrementalMode. | |
173 ICMSDisabler() { CMSCollector::disable_icms(); CMSCollector::start_icms(); } | |
174 ~ICMSDisabler() { CMSCollector::enable_icms(); } | |
175 }; | |
176 | |
177 ////////////////////////////////////////////////////////////////// | |
178 // Concurrent Mark-Sweep Generation ///////////////////////////// | |
179 ////////////////////////////////////////////////////////////////// | |
180 | |
181 NOT_PRODUCT(CompactibleFreeListSpace* debug_cms_space;) | |
182 | |
183 // This struct contains per-thread things necessary to support parallel | |
184 // young-gen collection. | |
6197 | 185 class CMSParGCThreadState: public CHeapObj<mtGC> { |
0 | 186 public: |
187 CFLS_LAB lab; | |
188 PromotionInfo promo; | |
189 | |
190 // Constructor. | |
191 CMSParGCThreadState(CompactibleFreeListSpace* cfls) : lab(cfls) { | |
192 promo.setSpace(cfls); | |
193 } | |
194 }; | |
195 | |
196 ConcurrentMarkSweepGeneration::ConcurrentMarkSweepGeneration( | |
197 ReservedSpace rs, size_t initial_byte_size, int level, | |
198 CardTableRS* ct, bool use_adaptive_freelists, | |
6026 | 199 FreeBlockDictionary<FreeChunk>::DictionaryChoice dictionaryChoice) : |
0 | 200 CardGeneration(rs, initial_byte_size, level, ct), |
1571
2d127394260e
6916623: Align object to 16 bytes to use Compressed Oops with java heap up to 64Gb
kvn
parents:
1521
diff
changeset
|
201 _dilatation_factor(((double)MinChunkSize)/((double)(CollectedHeap::min_fill_size()))), |
10244
06ab37f08701
8013184: CMS: Call reset_after_compaction() only if a compaction has been done
jmasa
parents:
10243
diff
changeset
|
202 _debug_collection_type(Concurrent_collection_type), |
06ab37f08701
8013184: CMS: Call reset_after_compaction() only if a compaction has been done
jmasa
parents:
10243
diff
changeset
|
203 _did_compact(false) |
0 | 204 { |
205 HeapWord* bottom = (HeapWord*) _virtual_space.low(); | |
206 HeapWord* end = (HeapWord*) _virtual_space.high(); | |
207 | |
208 _direct_allocated_words = 0; | |
209 NOT_PRODUCT( | |
210 _numObjectsPromoted = 0; | |
211 _numWordsPromoted = 0; | |
212 _numObjectsAllocated = 0; | |
213 _numWordsAllocated = 0; | |
214 ) | |
215 | |
216 _cmsSpace = new CompactibleFreeListSpace(_bts, MemRegion(bottom, end), | |
217 use_adaptive_freelists, | |
218 dictionaryChoice); | |
219 NOT_PRODUCT(debug_cms_space = _cmsSpace;) | |
220 if (_cmsSpace == NULL) { | |
221 vm_exit_during_initialization( | |
222 "CompactibleFreeListSpace allocation failure"); | |
223 } | |
224 _cmsSpace->_gen = this; | |
225 | |
226 _gc_stats = new CMSGCStats(); | |
227 | |
228 // Verify the assumption that FreeChunk::_prev and OopDesc::_klass | |
229 // offsets match. The ability to tell free chunks from objects | |
230 // depends on this property. | |
231 debug_only( | |
232 FreeChunk* junk = NULL; | |
12226
7944aba7ba41
8015107: NPG: Use consistent naming for metaspace concepts
ehelin
parents:
12112
diff
changeset
|
233 assert(UseCompressedClassPointers || |
187 | 234 junk->prev_addr() == (void*)(oop(junk)->klass_addr()), |
0 | 235 "Offset of FreeChunk::_prev within FreeChunk must match" |
236 " that of OopDesc::_klass within OopDesc"); | |
237 ) | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
238 if (CollectedHeap::use_parallel_gc_threads()) { |
0 | 239 typedef CMSParGCThreadState* CMSParGCThreadStatePtr; |
240 _par_gc_thread_states = | |
6197 | 241 NEW_C_HEAP_ARRAY(CMSParGCThreadStatePtr, ParallelGCThreads, mtGC); |
0 | 242 if (_par_gc_thread_states == NULL) { |
243 vm_exit_during_initialization("Could not allocate par gc structs"); | |
244 } | |
245 for (uint i = 0; i < ParallelGCThreads; i++) { | |
246 _par_gc_thread_states[i] = new CMSParGCThreadState(cmsSpace()); | |
247 if (_par_gc_thread_states[i] == NULL) { | |
248 vm_exit_during_initialization("Could not allocate par gc structs"); | |
249 } | |
250 } | |
251 } else { | |
252 _par_gc_thread_states = NULL; | |
253 } | |
254 _incremental_collection_failed = false; | |
255 // The "dilatation_factor" is the expansion that can occur on | |
256 // account of the fact that the minimum object size in the CMS | |
257 // generation may be larger than that in, say, a contiguous young | |
258 // generation. | |
259 // Ideally, in the calculation below, we'd compute the dilatation | |
260 // factor as: MinChunkSize/(promoting_gen's min object size) | |
261 // Since we do not have such a general query interface for the | |
14309 | 262 // promoting generation, we'll instead just use the minimum |
0 | 263 // object size (which today is a header's worth of space); |
264 // note that all arithmetic is in units of HeapWords. | |
1571
2d127394260e
6916623: Align object to 16 bytes to use Compressed Oops with java heap up to 64Gb
kvn
parents:
1521
diff
changeset
|
265 assert(MinChunkSize >= CollectedHeap::min_fill_size(), "just checking"); |
0 | 266 assert(_dilatation_factor >= 1.0, "from previous assert"); |
267 } | |
268 | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
269 |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
270 // The field "_initiating_occupancy" represents the occupancy percentage |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
271 // at which we trigger a new collection cycle. Unless explicitly specified |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
272 // via CMSInitiatingOccupancyFraction (argument "io" below), it |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
273 // is calculated by: |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
274 // |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
275 // Let "f" be MinHeapFreeRatio in |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
276 // |
14309 | 277 // _initiating_occupancy = 100-f + |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
278 // f * (CMSTriggerRatio/100) |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
279 // where CMSTriggerRatio is the argument "tr" below. |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
280 // |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
281 // That is, if we assume the heap is at its desired maximum occupancy at the |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
282 // end of a collection, we let CMSTriggerRatio of the (purported) free |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
283 // space be allocated before initiating a new collection cycle. |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
284 // |
8035 | 285 void ConcurrentMarkSweepGeneration::init_initiating_occupancy(intx io, uintx tr) { |
286 assert(io <= 100 && tr <= 100, "Check the arguments"); | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
287 if (io >= 0) { |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
288 _initiating_occupancy = (double)io / 100.0; |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
289 } else { |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
290 _initiating_occupancy = ((100 - MinHeapFreeRatio) + |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
291 (double)(tr * MinHeapFreeRatio) / 100.0) |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
292 / 100.0; |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
293 } |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
294 } |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
295 |
0 | 296 void ConcurrentMarkSweepGeneration::ref_processor_init() { |
297 assert(collector() != NULL, "no collector"); | |
298 collector()->ref_processor_init(); | |
299 } | |
300 | |
301 void CMSCollector::ref_processor_init() { | |
302 if (_ref_processor == NULL) { | |
303 // Allocate and initialize a reference processor | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
304 _ref_processor = |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
305 new ReferenceProcessor(_span, // span |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
306 (ParallelGCThreads > 1) && ParallelRefProcEnabled, // mt processing |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
307 (int) ParallelGCThreads, // mt processing degree |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
308 _cmsGen->refs_discovery_is_mt(), // mt discovery |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
309 (int) MAX2(ConcGCThreads, ParallelGCThreads), // mt discovery degree |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
310 _cmsGen->refs_discovery_is_atomic(), // discovery is not atomic |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
311 &_is_alive_closure, // closure for liveness info |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
312 false); // next field updates do not need write barrier |
0 | 313 // Initialize the _ref_processor field of CMSGen |
314 _cmsGen->set_ref_processor(_ref_processor); | |
315 | |
316 } | |
317 } | |
318 | |
319 CMSAdaptiveSizePolicy* CMSCollector::size_policy() { | |
320 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
321 assert(gch->kind() == CollectedHeap::GenCollectedHeap, | |
322 "Wrong type of heap"); | |
323 CMSAdaptiveSizePolicy* sp = (CMSAdaptiveSizePolicy*) | |
324 gch->gen_policy()->size_policy(); | |
325 assert(sp->is_gc_cms_adaptive_size_policy(), | |
326 "Wrong type of size policy"); | |
327 return sp; | |
328 } | |
329 | |
330 CMSGCAdaptivePolicyCounters* CMSCollector::gc_adaptive_policy_counters() { | |
331 CMSGCAdaptivePolicyCounters* results = | |
332 (CMSGCAdaptivePolicyCounters*) collector_policy()->counters(); | |
333 assert( | |
334 results->kind() == GCPolicyCounters::CMSGCAdaptivePolicyCountersKind, | |
335 "Wrong gc policy counter kind"); | |
336 return results; | |
337 } | |
338 | |
339 | |
340 void ConcurrentMarkSweepGeneration::initialize_performance_counters() { | |
341 | |
342 const char* gen_name = "old"; | |
343 | |
344 // Generation Counters - generation 1, 1 subspace | |
345 _gen_counters = new GenerationCounters(gen_name, 1, 1, &_virtual_space); | |
346 | |
347 _space_counters = new GSpaceCounters(gen_name, 0, | |
348 _virtual_space.reserved_size(), | |
349 this, _gen_counters); | |
350 } | |
351 | |
352 CMSStats::CMSStats(ConcurrentMarkSweepGeneration* cms_gen, unsigned int alpha): | |
353 _cms_gen(cms_gen) | |
354 { | |
355 assert(alpha <= 100, "bad value"); | |
356 _saved_alpha = alpha; | |
357 | |
358 // Initialize the alphas to the bootstrap value of 100. | |
359 _gc0_alpha = _cms_alpha = 100; | |
360 | |
361 _cms_begin_time.update(); | |
362 _cms_end_time.update(); | |
363 | |
364 _gc0_duration = 0.0; | |
365 _gc0_period = 0.0; | |
366 _gc0_promoted = 0; | |
367 | |
368 _cms_duration = 0.0; | |
369 _cms_period = 0.0; | |
370 _cms_allocated = 0; | |
371 | |
372 _cms_used_at_gc0_begin = 0; | |
373 _cms_used_at_gc0_end = 0; | |
374 _allow_duty_cycle_reduction = false; | |
375 _valid_bits = 0; | |
376 _icms_duty_cycle = CMSIncrementalDutyCycle; | |
377 } | |
378 | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
379 double CMSStats::cms_free_adjustment_factor(size_t free) const { |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
380 // TBD: CR 6909490 |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
381 return 1.0; |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
382 } |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
383 |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
384 void CMSStats::adjust_cms_free_adjustment_factor(bool fail, size_t free) { |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
385 } |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
386 |
0 | 387 // If promotion failure handling is on use |
388 // the padded average size of the promotion for each | |
389 // young generation collection. | |
390 double CMSStats::time_until_cms_gen_full() const { | |
391 size_t cms_free = _cms_gen->cmsSpace()->free(); | |
392 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
1888
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
393 size_t expected_promotion = MIN2(gch->get_gen(0)->capacity(), |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
394 (size_t) _cms_gen->gc_stats()->avg_promoted()->padded_average()); |
0 | 395 if (cms_free > expected_promotion) { |
396 // Start a cms collection if there isn't enough space to promote | |
397 // for the next minor collection. Use the padded average as | |
398 // a safety factor. | |
399 cms_free -= expected_promotion; | |
400 | |
401 // Adjust by the safety factor. | |
402 double cms_free_dbl = (double)cms_free; | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
403 double cms_adjustment = (100.0 - CMSIncrementalSafetyFactor)/100.0; |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
404 // Apply a further correction factor which tries to adjust |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
405 // for recent occurance of concurrent mode failures. |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
406 cms_adjustment = cms_adjustment * cms_free_adjustment_factor(cms_free); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
407 cms_free_dbl = cms_free_dbl * cms_adjustment; |
0 | 408 |
409 if (PrintGCDetails && Verbose) { | |
410 gclog_or_tty->print_cr("CMSStats::time_until_cms_gen_full: cms_free " | |
411 SIZE_FORMAT " expected_promotion " SIZE_FORMAT, | |
412 cms_free, expected_promotion); | |
413 gclog_or_tty->print_cr(" cms_free_dbl %f cms_consumption_rate %f", | |
414 cms_free_dbl, cms_consumption_rate() + 1.0); | |
415 } | |
416 // Add 1 in case the consumption rate goes to zero. | |
417 return cms_free_dbl / (cms_consumption_rate() + 1.0); | |
418 } | |
419 return 0.0; | |
420 } | |
421 | |
422 // Compare the duration of the cms collection to the | |
423 // time remaining before the cms generation is empty. | |
424 // Note that the time from the start of the cms collection | |
425 // to the start of the cms sweep (less than the total | |
426 // duration of the cms collection) can be used. This | |
427 // has been tried and some applications experienced | |
428 // promotion failures early in execution. This was | |
429 // possibly because the averages were not accurate | |
430 // enough at the beginning. | |
431 double CMSStats::time_until_cms_start() const { | |
432 // We add "gc0_period" to the "work" calculation | |
433 // below because this query is done (mostly) at the | |
434 // end of a scavenge, so we need to conservatively | |
435 // account for that much possible delay | |
436 // in the query so as to avoid concurrent mode failures | |
437 // due to starting the collection just a wee bit too | |
438 // late. | |
439 double work = cms_duration() + gc0_period(); | |
440 double deadline = time_until_cms_gen_full(); | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
441 // If a concurrent mode failure occurred recently, we want to be |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
442 // more conservative and halve our expected time_until_cms_gen_full() |
0 | 443 if (work > deadline) { |
444 if (Verbose && PrintGCDetails) { | |
445 gclog_or_tty->print( | |
446 " CMSCollector: collect because of anticipated promotion " | |
447 "before full %3.7f + %3.7f > %3.7f ", cms_duration(), | |
448 gc0_period(), time_until_cms_gen_full()); | |
449 } | |
450 return 0.0; | |
451 } | |
452 return work - deadline; | |
453 } | |
454 | |
455 // Return a duty cycle based on old_duty_cycle and new_duty_cycle, limiting the | |
456 // amount of change to prevent wild oscillation. | |
457 unsigned int CMSStats::icms_damped_duty_cycle(unsigned int old_duty_cycle, | |
458 unsigned int new_duty_cycle) { | |
459 assert(old_duty_cycle <= 100, "bad input value"); | |
460 assert(new_duty_cycle <= 100, "bad input value"); | |
461 | |
462 // Note: use subtraction with caution since it may underflow (values are | |
463 // unsigned). Addition is safe since we're in the range 0-100. | |
464 unsigned int damped_duty_cycle = new_duty_cycle; | |
465 if (new_duty_cycle < old_duty_cycle) { | |
466 const unsigned int largest_delta = MAX2(old_duty_cycle / 4, 5U); | |
467 if (new_duty_cycle + largest_delta < old_duty_cycle) { | |
468 damped_duty_cycle = old_duty_cycle - largest_delta; | |
469 } | |
470 } else if (new_duty_cycle > old_duty_cycle) { | |
471 const unsigned int largest_delta = MAX2(old_duty_cycle / 4, 15U); | |
472 if (new_duty_cycle > old_duty_cycle + largest_delta) { | |
473 damped_duty_cycle = MIN2(old_duty_cycle + largest_delta, 100U); | |
474 } | |
475 } | |
476 assert(damped_duty_cycle <= 100, "invalid duty cycle computed"); | |
477 | |
478 if (CMSTraceIncrementalPacing) { | |
479 gclog_or_tty->print(" [icms_damped_duty_cycle(%d,%d) = %d] ", | |
480 old_duty_cycle, new_duty_cycle, damped_duty_cycle); | |
481 } | |
482 return damped_duty_cycle; | |
483 } | |
484 | |
485 unsigned int CMSStats::icms_update_duty_cycle_impl() { | |
486 assert(CMSIncrementalPacing && valid(), | |
487 "should be handled in icms_update_duty_cycle()"); | |
488 | |
489 double cms_time_so_far = cms_timer().seconds(); | |
490 double scaled_duration = cms_duration_per_mb() * _cms_used_at_gc0_end / M; | |
491 double scaled_duration_remaining = fabsd(scaled_duration - cms_time_so_far); | |
492 | |
493 // Avoid division by 0. | |
494 double time_until_full = MAX2(time_until_cms_gen_full(), 0.01); | |
495 double duty_cycle_dbl = 100.0 * scaled_duration_remaining / time_until_full; | |
496 | |
497 unsigned int new_duty_cycle = MIN2((unsigned int)duty_cycle_dbl, 100U); | |
498 if (new_duty_cycle > _icms_duty_cycle) { | |
499 // Avoid very small duty cycles (1 or 2); 0 is allowed. | |
500 if (new_duty_cycle > 2) { | |
501 _icms_duty_cycle = icms_damped_duty_cycle(_icms_duty_cycle, | |
502 new_duty_cycle); | |
503 } | |
504 } else if (_allow_duty_cycle_reduction) { | |
505 // The duty cycle is reduced only once per cms cycle (see record_cms_end()). | |
506 new_duty_cycle = icms_damped_duty_cycle(_icms_duty_cycle, new_duty_cycle); | |
507 // Respect the minimum duty cycle. | |
508 unsigned int min_duty_cycle = (unsigned int)CMSIncrementalDutyCycleMin; | |
509 _icms_duty_cycle = MAX2(new_duty_cycle, min_duty_cycle); | |
510 } | |
511 | |
512 if (PrintGCDetails || CMSTraceIncrementalPacing) { | |
513 gclog_or_tty->print(" icms_dc=%d ", _icms_duty_cycle); | |
514 } | |
515 | |
516 _allow_duty_cycle_reduction = false; | |
517 return _icms_duty_cycle; | |
518 } | |
519 | |
520 #ifndef PRODUCT | |
521 void CMSStats::print_on(outputStream *st) const { | |
522 st->print(" gc0_alpha=%d,cms_alpha=%d", _gc0_alpha, _cms_alpha); | |
523 st->print(",gc0_dur=%g,gc0_per=%g,gc0_promo=" SIZE_FORMAT, | |
524 gc0_duration(), gc0_period(), gc0_promoted()); | |
525 st->print(",cms_dur=%g,cms_dur_per_mb=%g,cms_per=%g,cms_alloc=" SIZE_FORMAT, | |
526 cms_duration(), cms_duration_per_mb(), | |
527 cms_period(), cms_allocated()); | |
528 st->print(",cms_since_beg=%g,cms_since_end=%g", | |
529 cms_time_since_begin(), cms_time_since_end()); | |
530 st->print(",cms_used_beg=" SIZE_FORMAT ",cms_used_end=" SIZE_FORMAT, | |
531 _cms_used_at_gc0_begin, _cms_used_at_gc0_end); | |
532 if (CMSIncrementalMode) { | |
533 st->print(",dc=%d", icms_duty_cycle()); | |
534 } | |
535 | |
536 if (valid()) { | |
537 st->print(",promo_rate=%g,cms_alloc_rate=%g", | |
538 promotion_rate(), cms_allocation_rate()); | |
539 st->print(",cms_consumption_rate=%g,time_until_full=%g", | |
540 cms_consumption_rate(), time_until_cms_gen_full()); | |
541 } | |
542 st->print(" "); | |
543 } | |
544 #endif // #ifndef PRODUCT | |
545 | |
546 CMSCollector::CollectorState CMSCollector::_collectorState = | |
547 CMSCollector::Idling; | |
548 bool CMSCollector::_foregroundGCIsActive = false; | |
549 bool CMSCollector::_foregroundGCShouldWait = false; | |
550 | |
551 CMSCollector::CMSCollector(ConcurrentMarkSweepGeneration* cmsGen, | |
552 CardTableRS* ct, | |
553 ConcurrentMarkSweepPolicy* cp): | |
554 _cmsGen(cmsGen), | |
555 _ct(ct), | |
556 _ref_processor(NULL), // will be set later | |
557 _conc_workers(NULL), // may be set later | |
558 _abort_preclean(false), | |
559 _start_sampling(false), | |
560 _between_prologue_and_epilogue(false), | |
561 _markBitMap(0, Mutex::leaf + 1, "CMS_markBitMap_lock"), | |
562 _modUnionTable((CardTableModRefBS::card_shift - LogHeapWordSize), | |
563 -1 /* lock-free */, "No_lock" /* dummy */), | |
564 _modUnionClosure(&_modUnionTable), | |
565 _modUnionClosurePar(&_modUnionTable), | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
566 // Adjust my span to cover old (cms) gen |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
567 _span(cmsGen->reserved()), |
143
b5489bb705c9
6662086: 6u4+, 7b11+: CMS never clears referents when -XX:+ParallelRefProcEnabled
ysr
parents:
113
diff
changeset
|
568 // Construct the is_alive_closure with _span & markBitMap |
b5489bb705c9
6662086: 6u4+, 7b11+: CMS never clears referents when -XX:+ParallelRefProcEnabled
ysr
parents:
113
diff
changeset
|
569 _is_alive_closure(_span, &_markBitMap), |
0 | 570 _restart_addr(NULL), |
571 _overflow_list(NULL), | |
572 _stats(cmsGen), | |
11973
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
573 _eden_chunk_lock(new Mutex(Mutex::leaf + 1, "CMS_eden_chunk_lock", true)), |
0 | 574 _eden_chunk_array(NULL), // may be set in ctor body |
575 _eden_chunk_capacity(0), // -- ditto -- | |
576 _eden_chunk_index(0), // -- ditto -- | |
577 _survivor_plab_array(NULL), // -- ditto -- | |
578 _survivor_chunk_array(NULL), // -- ditto -- | |
579 _survivor_chunk_capacity(0), // -- ditto -- | |
580 _survivor_chunk_index(0), // -- ditto -- | |
581 _ser_pmc_preclean_ovflw(0), | |
452
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
582 _ser_kac_preclean_ovflw(0), |
0 | 583 _ser_pmc_remark_ovflw(0), |
584 _par_pmc_remark_ovflw(0), | |
585 _ser_kac_ovflw(0), | |
586 _par_kac_ovflw(0), | |
587 #ifndef PRODUCT | |
588 _num_par_pushes(0), | |
589 #endif | |
590 _collection_count_start(0), | |
591 _verifying(false), | |
592 _icms_start_limit(NULL), | |
593 _icms_stop_limit(NULL), | |
594 _verification_mark_bm(0, Mutex::leaf + 1, "CMS_verification_mark_bm_lock"), | |
595 _completed_initialization(false), | |
596 _collector_policy(cp), | |
13063
40b8c6bad703
8024954: CMS: CMSClassUnloadingMaxInterval is not implemented correctly. This change is also part of the fix for 8024483.
jmasa
parents:
12316
diff
changeset
|
597 _should_unload_classes(CMSClassUnloadingEnabled), |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
598 _concurrent_cycles_since_last_unload(0), |
13063
40b8c6bad703
8024954: CMS: CMSClassUnloadingMaxInterval is not implemented correctly. This change is also part of the fix for 8024483.
jmasa
parents:
12316
diff
changeset
|
599 _roots_scanning_options(SharedHeap::SO_None), |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
600 _inter_sweep_estimate(CMS_SweepWeight, CMS_SweepPadding), |
10405 | 601 _intra_sweep_estimate(CMS_SweepWeight, CMS_SweepPadding), |
602 _gc_tracer_cm(new (ResourceObj::C_HEAP, mtGC) CMSTracer()), | |
603 _gc_timer_cm(new (ResourceObj::C_HEAP, mtGC) ConcurrentGCTimer()), | |
604 _cms_start_registered(false) | |
0 | 605 { |
606 if (ExplicitGCInvokesConcurrentAndUnloadsClasses) { | |
607 ExplicitGCInvokesConcurrent = true; | |
608 } | |
609 // Now expand the span and allocate the collection support structures | |
610 // (MUT, marking bit map etc.) to cover both generations subject to | |
611 // collection. | |
612 | |
613 // For use by dirty card to oop closures. | |
614 _cmsGen->cmsSpace()->set_collector(this); | |
615 | |
616 // Allocate MUT and marking bit map | |
617 { | |
618 MutexLockerEx x(_markBitMap.lock(), Mutex::_no_safepoint_check_flag); | |
619 if (!_markBitMap.allocate(_span)) { | |
620 warning("Failed to allocate CMS Bit Map"); | |
621 return; | |
622 } | |
623 assert(_markBitMap.covers(_span), "_markBitMap inconsistency?"); | |
624 } | |
625 { | |
626 _modUnionTable.allocate(_span); | |
627 assert(_modUnionTable.covers(_span), "_modUnionTable inconsistency?"); | |
628 } | |
629 | |
1284 | 630 if (!_markStack.allocate(MarkStackSize)) { |
0 | 631 warning("Failed to allocate CMS Marking Stack"); |
632 return; | |
633 } | |
634 | |
635 // Support for multi-threaded concurrent phases | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
636 if (CMSConcurrentMTEnabled) { |
1284 | 637 if (FLAG_IS_DEFAULT(ConcGCThreads)) { |
0 | 638 // just for now |
1284 | 639 FLAG_SET_DEFAULT(ConcGCThreads, (ParallelGCThreads + 3)/4); |
640 } | |
641 if (ConcGCThreads > 1) { | |
0 | 642 _conc_workers = new YieldingFlexibleWorkGang("Parallel CMS Threads", |
1284 | 643 ConcGCThreads, true); |
0 | 644 if (_conc_workers == NULL) { |
645 warning("GC/CMS: _conc_workers allocation failure: " | |
646 "forcing -CMSConcurrentMTEnabled"); | |
647 CMSConcurrentMTEnabled = false; | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
648 } else { |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
649 _conc_workers->initialize_workers(); |
0 | 650 } |
651 } else { | |
652 CMSConcurrentMTEnabled = false; | |
653 } | |
654 } | |
655 if (!CMSConcurrentMTEnabled) { | |
1284 | 656 ConcGCThreads = 0; |
0 | 657 } else { |
658 // Turn off CMSCleanOnEnter optimization temporarily for | |
659 // the MT case where it's not fixed yet; see 6178663. | |
660 CMSCleanOnEnter = false; | |
661 } | |
1284 | 662 assert((_conc_workers != NULL) == (ConcGCThreads > 1), |
0 | 663 "Inconsistency"); |
664 | |
665 // Parallel task queues; these are shared for the | |
666 // concurrent and stop-world phases of CMS, but | |
667 // are not shared with parallel scavenge (ParNew). | |
668 { | |
669 uint i; | |
1284 | 670 uint num_queues = (uint) MAX2(ParallelGCThreads, ConcGCThreads); |
0 | 671 |
672 if ((CMSParallelRemarkEnabled || CMSConcurrentMTEnabled | |
673 || ParallelRefProcEnabled) | |
674 && num_queues > 0) { | |
675 _task_queues = new OopTaskQueueSet(num_queues); | |
676 if (_task_queues == NULL) { | |
677 warning("task_queues allocation failure."); | |
678 return; | |
679 } | |
6197 | 680 _hash_seed = NEW_C_HEAP_ARRAY(int, num_queues, mtGC); |
0 | 681 if (_hash_seed == NULL) { |
682 warning("_hash_seed array allocation failure"); | |
683 return; | |
684 } | |
685 | |
1665 | 686 typedef Padded<OopTaskQueue> PaddedOopTaskQueue; |
0 | 687 for (i = 0; i < num_queues; i++) { |
1665 | 688 PaddedOopTaskQueue *q = new PaddedOopTaskQueue(); |
689 if (q == NULL) { | |
0 | 690 warning("work_queue allocation failure."); |
691 return; | |
692 } | |
1665 | 693 _task_queues->register_queue(i, q); |
0 | 694 } |
695 for (i = 0; i < num_queues; i++) { | |
696 _task_queues->queue(i)->initialize(); | |
697 _hash_seed[i] = 17; // copied from ParNew | |
698 } | |
699 } | |
700 } | |
701 | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
702 _cmsGen ->init_initiating_occupancy(CMSInitiatingOccupancyFraction, CMSTriggerRatio); |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
703 |
0 | 704 // Clip CMSBootstrapOccupancy between 0 and 100. |
10287
12f651e29f6b
6843347: Boundary values in some public GC options cause crashes
tschatzl
parents:
10244
diff
changeset
|
705 _bootstrap_occupancy = ((double)CMSBootstrapOccupancy)/(double)100; |
0 | 706 |
707 _full_gcs_since_conc_gc = 0; | |
708 | |
709 // Now tell CMS generations the identity of their collector | |
710 ConcurrentMarkSweepGeneration::set_collector(this); | |
711 | |
712 // Create & start a CMS thread for this CMS collector | |
713 _cmsThread = ConcurrentMarkSweepThread::start(this); | |
714 assert(cmsThread() != NULL, "CMS Thread should have been created"); | |
715 assert(cmsThread()->collector() == this, | |
716 "CMS Thread should refer to this gen"); | |
717 assert(CGC_lock != NULL, "Where's the CGC_lock?"); | |
718 | |
719 // Support for parallelizing young gen rescan | |
720 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
721 _young_gen = gch->prev_gen(_cmsGen); | |
722 if (gch->supports_inline_contig_alloc()) { | |
723 _top_addr = gch->top_addr(); | |
724 _end_addr = gch->end_addr(); | |
725 assert(_young_gen != NULL, "no _young_gen"); | |
726 _eden_chunk_index = 0; | |
727 _eden_chunk_capacity = (_young_gen->max_capacity()+CMSSamplingGrain)/CMSSamplingGrain; | |
6197 | 728 _eden_chunk_array = NEW_C_HEAP_ARRAY(HeapWord*, _eden_chunk_capacity, mtGC); |
0 | 729 if (_eden_chunk_array == NULL) { |
730 _eden_chunk_capacity = 0; | |
731 warning("GC/CMS: _eden_chunk_array allocation failure"); | |
732 } | |
733 } | |
734 assert(_eden_chunk_array != NULL || _eden_chunk_capacity == 0, "Error"); | |
735 | |
736 // Support for parallelizing survivor space rescan | |
11975 | 737 if ((CMSParallelRemarkEnabled && CMSParallelSurvivorRemarkEnabled) || CMSParallelInitialMarkEnabled) { |
1289
d47555d7aca8
6910182: CMS: assert(_cursor[j] == _survivor_plab_array[j].end(),"Ctl pt invariant")
jmasa
parents:
1284
diff
changeset
|
738 const size_t max_plab_samples = |
d47555d7aca8
6910182: CMS: assert(_cursor[j] == _survivor_plab_array[j].end(),"Ctl pt invariant")
jmasa
parents:
1284
diff
changeset
|
739 ((DefNewGeneration*)_young_gen)->max_survivor_size()/MinTLABSize; |
d47555d7aca8
6910182: CMS: assert(_cursor[j] == _survivor_plab_array[j].end(),"Ctl pt invariant")
jmasa
parents:
1284
diff
changeset
|
740 |
6197 | 741 _survivor_plab_array = NEW_C_HEAP_ARRAY(ChunkArray, ParallelGCThreads, mtGC); |
742 _survivor_chunk_array = NEW_C_HEAP_ARRAY(HeapWord*, 2*max_plab_samples, mtGC); | |
743 _cursor = NEW_C_HEAP_ARRAY(size_t, ParallelGCThreads, mtGC); | |
0 | 744 if (_survivor_plab_array == NULL || _survivor_chunk_array == NULL |
745 || _cursor == NULL) { | |
746 warning("Failed to allocate survivor plab/chunk array"); | |
747 if (_survivor_plab_array != NULL) { | |
6197 | 748 FREE_C_HEAP_ARRAY(ChunkArray, _survivor_plab_array, mtGC); |
0 | 749 _survivor_plab_array = NULL; |
750 } | |
751 if (_survivor_chunk_array != NULL) { | |
6197 | 752 FREE_C_HEAP_ARRAY(HeapWord*, _survivor_chunk_array, mtGC); |
0 | 753 _survivor_chunk_array = NULL; |
754 } | |
755 if (_cursor != NULL) { | |
6197 | 756 FREE_C_HEAP_ARRAY(size_t, _cursor, mtGC); |
0 | 757 _cursor = NULL; |
758 } | |
759 } else { | |
760 _survivor_chunk_capacity = 2*max_plab_samples; | |
761 for (uint i = 0; i < ParallelGCThreads; i++) { | |
6197 | 762 HeapWord** vec = NEW_C_HEAP_ARRAY(HeapWord*, max_plab_samples, mtGC); |
0 | 763 if (vec == NULL) { |
764 warning("Failed to allocate survivor plab array"); | |
765 for (int j = i; j > 0; j--) { | |
6197 | 766 FREE_C_HEAP_ARRAY(HeapWord*, _survivor_plab_array[j-1].array(), mtGC); |
0 | 767 } |
6197 | 768 FREE_C_HEAP_ARRAY(ChunkArray, _survivor_plab_array, mtGC); |
769 FREE_C_HEAP_ARRAY(HeapWord*, _survivor_chunk_array, mtGC); | |
0 | 770 _survivor_plab_array = NULL; |
771 _survivor_chunk_array = NULL; | |
772 _survivor_chunk_capacity = 0; | |
773 break; | |
774 } else { | |
775 ChunkArray* cur = | |
776 ::new (&_survivor_plab_array[i]) ChunkArray(vec, | |
777 max_plab_samples); | |
778 assert(cur->end() == 0, "Should be 0"); | |
779 assert(cur->array() == vec, "Should be vec"); | |
780 assert(cur->capacity() == max_plab_samples, "Error"); | |
781 } | |
782 } | |
783 } | |
784 } | |
785 assert( ( _survivor_plab_array != NULL | |
786 && _survivor_chunk_array != NULL) | |
787 || ( _survivor_chunk_capacity == 0 | |
788 && _survivor_chunk_index == 0), | |
789 "Error"); | |
790 | |
791 NOT_PRODUCT(_overflow_counter = CMSMarkStackOverflowInterval;) | |
792 _gc_counters = new CollectorCounters("CMS", 1); | |
793 _completed_initialization = true; | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
794 _inter_sweep_timer.start(); // start of time |
0 | 795 } |
796 | |
797 const char* ConcurrentMarkSweepGeneration::name() const { | |
798 return "concurrent mark-sweep generation"; | |
799 } | |
800 void ConcurrentMarkSweepGeneration::update_counters() { | |
801 if (UsePerfData) { | |
802 _space_counters->update_all(); | |
803 _gen_counters->update_all(); | |
804 } | |
805 } | |
806 | |
807 // this is an optimized version of update_counters(). it takes the | |
808 // used value as a parameter rather than computing it. | |
809 // | |
810 void ConcurrentMarkSweepGeneration::update_counters(size_t used) { | |
811 if (UsePerfData) { | |
812 _space_counters->update_used(used); | |
813 _space_counters->update_capacity(); | |
814 _gen_counters->update_all(); | |
815 } | |
816 } | |
817 | |
818 void ConcurrentMarkSweepGeneration::print() const { | |
819 Generation::print(); | |
820 cmsSpace()->print(); | |
821 } | |
822 | |
823 #ifndef PRODUCT | |
824 void ConcurrentMarkSweepGeneration::print_statistics() { | |
825 cmsSpace()->printFLCensus(0); | |
826 } | |
827 #endif | |
828 | |
829 void ConcurrentMarkSweepGeneration::printOccupancy(const char *s) { | |
830 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
831 if (PrintGCDetails) { | |
832 if (Verbose) { | |
7455
0b54ffe4c2d3
8005672: Clean up some changes to GC logging with GCCause's
jmasa
parents:
6885
diff
changeset
|
833 gclog_or_tty->print("[%d %s-%s: "SIZE_FORMAT"("SIZE_FORMAT")]", |
0 | 834 level(), short_name(), s, used(), capacity()); |
835 } else { | |
7455
0b54ffe4c2d3
8005672: Clean up some changes to GC logging with GCCause's
jmasa
parents:
6885
diff
changeset
|
836 gclog_or_tty->print("[%d %s-%s: "SIZE_FORMAT"K("SIZE_FORMAT"K)]", |
0 | 837 level(), short_name(), s, used() / K, capacity() / K); |
838 } | |
839 } | |
840 if (Verbose) { | |
841 gclog_or_tty->print(" "SIZE_FORMAT"("SIZE_FORMAT")", | |
842 gch->used(), gch->capacity()); | |
843 } else { | |
844 gclog_or_tty->print(" "SIZE_FORMAT"K("SIZE_FORMAT"K)", | |
845 gch->used() / K, gch->capacity() / K); | |
846 } | |
847 } | |
848 | |
849 size_t | |
850 ConcurrentMarkSweepGeneration::contiguous_available() const { | |
851 // dld proposes an improvement in precision here. If the committed | |
852 // part of the space ends in a free block we should add that to | |
853 // uncommitted size in the calculation below. Will make this | |
854 // change later, staying with the approximation below for the | |
855 // time being. -- ysr. | |
856 return MAX2(_virtual_space.uncommitted_size(), unsafe_max_alloc_nogc()); | |
857 } | |
858 | |
859 size_t | |
860 ConcurrentMarkSweepGeneration::unsafe_max_alloc_nogc() const { | |
861 return _cmsSpace->max_alloc_in_words() * HeapWordSize; | |
862 } | |
863 | |
864 size_t ConcurrentMarkSweepGeneration::max_available() const { | |
865 return free() + _virtual_space.uncommitted_size(); | |
866 } | |
867 | |
1888
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
868 bool ConcurrentMarkSweepGeneration::promotion_attempt_is_safe(size_t max_promotion_in_bytes) const { |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
869 size_t available = max_available(); |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
870 size_t av_promo = (size_t)gc_stats()->avg_promoted()->padded_average(); |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
871 bool res = (available >= av_promo) || (available >= max_promotion_in_bytes); |
1994
6cd6d394f280
7001033: assert(gch->gc_cause() == GCCause::_scavenge_alot || !gch->incremental_collection_failed())
ysr
parents:
1972
diff
changeset
|
872 if (Verbose && PrintGCDetails) { |
1888
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
873 gclog_or_tty->print_cr( |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
874 "CMS: promo attempt is%s safe: available("SIZE_FORMAT") %s av_promo("SIZE_FORMAT")," |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
875 "max_promo("SIZE_FORMAT")", |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
876 res? "":" not", available, res? ">=":"<", |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
877 av_promo, max_promotion_in_bytes); |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
878 } |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
879 return res; |
0 | 880 } |
881 | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
882 // At a promotion failure dump information on block layout in heap |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
883 // (cms old generation). |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
884 void ConcurrentMarkSweepGeneration::promotion_failure_occurred() { |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
885 if (CMSDumpAtPromotionFailure) { |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
886 cmsSpace()->dump_at_safepoint_with_locks(collector(), gclog_or_tty); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
887 } |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
888 } |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
889 |
0 | 890 CompactibleSpace* |
891 ConcurrentMarkSweepGeneration::first_compaction_space() const { | |
892 return _cmsSpace; | |
893 } | |
894 | |
895 void ConcurrentMarkSweepGeneration::reset_after_compaction() { | |
896 // Clear the promotion information. These pointers can be adjusted | |
897 // along with all the other pointers into the heap but | |
898 // compaction is expected to be a rare event with | |
899 // a heap using cms so don't do it without seeing the need. | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
900 if (CollectedHeap::use_parallel_gc_threads()) { |
0 | 901 for (uint i = 0; i < ParallelGCThreads; i++) { |
902 _par_gc_thread_states[i]->promo.reset(); | |
903 } | |
904 } | |
905 } | |
906 | |
907 void ConcurrentMarkSweepGeneration::space_iterate(SpaceClosure* blk, bool usedOnly) { | |
908 blk->do_space(_cmsSpace); | |
909 } | |
910 | |
911 void ConcurrentMarkSweepGeneration::compute_new_size() { | |
912 assert_locked_or_safepoint(Heap_lock); | |
913 | |
914 // If incremental collection failed, we just want to expand | |
915 // to the limit. | |
916 if (incremental_collection_failed()) { | |
917 clear_incremental_collection_failed(); | |
918 grow_to_reserved(); | |
919 return; | |
920 } | |
921 | |
10243
a9d568b7df60
8013032: CMS: assert(used() == used_after_gc && used_after_gc <= capacity()) failed: used: 0 used_after_gc: 292080 capacity: 1431699456
jmasa
parents:
10188
diff
changeset
|
922 // The heap has been compacted but not reset yet. |
a9d568b7df60
8013032: CMS: assert(used() == used_after_gc && used_after_gc <= capacity()) failed: used: 0 used_after_gc: 292080 capacity: 1431699456
jmasa
parents:
10188
diff
changeset
|
923 // Any metric such as free() or used() will be incorrect. |
9072
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
924 |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
925 CardGeneration::compute_new_size(); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
926 |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
927 // Reset again after a possible resizing |
10244
06ab37f08701
8013184: CMS: Call reset_after_compaction() only if a compaction has been done
jmasa
parents:
10243
diff
changeset
|
928 if (did_compact()) { |
06ab37f08701
8013184: CMS: Call reset_after_compaction() only if a compaction has been done
jmasa
parents:
10243
diff
changeset
|
929 cmsSpace()->reset_after_compaction(); |
06ab37f08701
8013184: CMS: Call reset_after_compaction() only if a compaction has been done
jmasa
parents:
10243
diff
changeset
|
930 } |
9072
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
931 } |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
932 |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
933 void ConcurrentMarkSweepGeneration::compute_new_size_free_list() { |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
934 assert_locked_or_safepoint(Heap_lock); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
935 |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
936 // If incremental collection failed, we just want to expand |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
937 // to the limit. |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
938 if (incremental_collection_failed()) { |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
939 clear_incremental_collection_failed(); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
940 grow_to_reserved(); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
941 return; |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
942 } |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
943 |
0 | 944 double free_percentage = ((double) free()) / capacity(); |
945 double desired_free_percentage = (double) MinHeapFreeRatio / 100; | |
946 double maximum_free_percentage = (double) MaxHeapFreeRatio / 100; | |
947 | |
948 // compute expansion delta needed for reaching desired free percentage | |
949 if (free_percentage < desired_free_percentage) { | |
950 size_t desired_capacity = (size_t)(used() / ((double) 1 - desired_free_percentage)); | |
951 assert(desired_capacity >= capacity(), "invalid expansion size"); | |
9072
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
952 size_t expand_bytes = MAX2(desired_capacity - capacity(), MinHeapDeltaBytes); |
0 | 953 if (PrintGCDetails && Verbose) { |
954 size_t desired_capacity = (size_t)(used() / ((double) 1 - desired_free_percentage)); | |
955 gclog_or_tty->print_cr("\nFrom compute_new_size: "); | |
956 gclog_or_tty->print_cr(" Free fraction %f", free_percentage); | |
957 gclog_or_tty->print_cr(" Desired free fraction %f", | |
958 desired_free_percentage); | |
959 gclog_or_tty->print_cr(" Maximum free fraction %f", | |
960 maximum_free_percentage); | |
14358 | 961 gclog_or_tty->print_cr(" Capacity "SIZE_FORMAT, capacity()/1000); |
0 | 962 gclog_or_tty->print_cr(" Desired capacity "SIZE_FORMAT, |
963 desired_capacity/1000); | |
964 int prev_level = level() - 1; | |
965 if (prev_level >= 0) { | |
966 size_t prev_size = 0; | |
967 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
968 Generation* prev_gen = gch->_gens[prev_level]; | |
969 prev_size = prev_gen->capacity(); | |
970 gclog_or_tty->print_cr(" Younger gen size "SIZE_FORMAT, | |
971 prev_size/1000); | |
972 } | |
973 gclog_or_tty->print_cr(" unsafe_max_alloc_nogc "SIZE_FORMAT, | |
974 unsafe_max_alloc_nogc()/1000); | |
975 gclog_or_tty->print_cr(" contiguous available "SIZE_FORMAT, | |
976 contiguous_available()/1000); | |
977 gclog_or_tty->print_cr(" Expand by "SIZE_FORMAT" (bytes)", | |
978 expand_bytes); | |
979 } | |
980 // safe if expansion fails | |
981 expand(expand_bytes, 0, CMSExpansionCause::_satisfy_free_ratio); | |
982 if (PrintGCDetails && Verbose) { | |
983 gclog_or_tty->print_cr(" Expanded free fraction %f", | |
984 ((double) free()) / capacity()); | |
985 } | |
9072
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
986 } else { |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
987 size_t desired_capacity = (size_t)(used() / ((double) 1 - desired_free_percentage)); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
988 assert(desired_capacity <= capacity(), "invalid expansion size"); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
989 size_t shrink_bytes = capacity() - desired_capacity; |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
990 // Don't shrink unless the delta is greater than the minimum shrink we want |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
991 if (shrink_bytes >= MinHeapDeltaBytes) { |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
992 shrink_free_list_by(shrink_bytes); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
993 } |
0 | 994 } |
995 } | |
996 | |
997 Mutex* ConcurrentMarkSweepGeneration::freelistLock() const { | |
998 return cmsSpace()->freelistLock(); | |
999 } | |
1000 | |
1001 HeapWord* ConcurrentMarkSweepGeneration::allocate(size_t size, | |
1002 bool tlab) { | |
1003 CMSSynchronousYieldRequest yr; | |
1004 MutexLockerEx x(freelistLock(), | |
1005 Mutex::_no_safepoint_check_flag); | |
1006 return have_lock_and_allocate(size, tlab); | |
1007 } | |
1008 | |
1009 HeapWord* ConcurrentMarkSweepGeneration::have_lock_and_allocate(size_t size, | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1010 bool tlab /* ignored */) { |
0 | 1011 assert_lock_strong(freelistLock()); |
1012 size_t adjustedSize = CompactibleFreeListSpace::adjustObjectSize(size); | |
1013 HeapWord* res = cmsSpace()->allocate(adjustedSize); | |
1014 // Allocate the object live (grey) if the background collector has | |
1015 // started marking. This is necessary because the marker may | |
1016 // have passed this address and consequently this object will | |
1017 // not otherwise be greyed and would be incorrectly swept up. | |
1018 // Note that if this object contains references, the writing | |
1019 // of those references will dirty the card containing this object | |
1020 // allowing the object to be blackened (and its references scanned) | |
1021 // either during a preclean phase or at the final checkpoint. | |
1022 if (res != NULL) { | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1023 // We may block here with an uninitialized object with |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1024 // its mark-bit or P-bits not yet set. Such objects need |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1025 // to be safely navigable by block_start(). |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1026 assert(oop(res)->klass_or_null() == NULL, "Object should be uninitialized here."); |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
1027 assert(!((FreeChunk*)res)->is_free(), "Error, block will look free but show wrong size"); |
0 | 1028 collector()->direct_allocated(res, adjustedSize); |
1029 _direct_allocated_words += adjustedSize; | |
1030 // allocation counters | |
1031 NOT_PRODUCT( | |
1032 _numObjectsAllocated++; | |
1033 _numWordsAllocated += (int)adjustedSize; | |
1034 ) | |
1035 } | |
1036 return res; | |
1037 } | |
1038 | |
1039 // In the case of direct allocation by mutators in a generation that | |
1040 // is being concurrently collected, the object must be allocated | |
1041 // live (grey) if the background collector has started marking. | |
1042 // This is necessary because the marker may | |
1043 // have passed this address and consequently this object will | |
1044 // not otherwise be greyed and would be incorrectly swept up. | |
1045 // Note that if this object contains references, the writing | |
1046 // of those references will dirty the card containing this object | |
1047 // allowing the object to be blackened (and its references scanned) | |
1048 // either during a preclean phase or at the final checkpoint. | |
1049 void CMSCollector::direct_allocated(HeapWord* start, size_t size) { | |
1050 assert(_markBitMap.covers(start, size), "Out of bounds"); | |
1051 if (_collectorState >= Marking) { | |
1052 MutexLockerEx y(_markBitMap.lock(), | |
1053 Mutex::_no_safepoint_check_flag); | |
1054 // [see comments preceding SweepClosure::do_blk() below for details] | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1055 // |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1056 // Can the P-bits be deleted now? JJJ |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1057 // |
0 | 1058 // 1. need to mark the object as live so it isn't collected |
1059 // 2. need to mark the 2nd bit to indicate the object may be uninitialized | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1060 // 3. need to mark the end of the object so marking, precleaning or sweeping |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1061 // can skip over uninitialized or unparsable objects. An allocated |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1062 // object is considered uninitialized for our purposes as long as |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1063 // its klass word is NULL. All old gen objects are parsable |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1064 // as soon as they are initialized.) |
0 | 1065 _markBitMap.mark(start); // object is live |
1066 _markBitMap.mark(start + 1); // object is potentially uninitialized? | |
1067 _markBitMap.mark(start + size - 1); | |
1068 // mark end of object | |
1069 } | |
1070 // check that oop looks uninitialized | |
187 | 1071 assert(oop(start)->klass_or_null() == NULL, "_klass should be NULL"); |
0 | 1072 } |
1073 | |
1074 void CMSCollector::promoted(bool par, HeapWord* start, | |
1075 bool is_obj_array, size_t obj_size) { | |
1076 assert(_markBitMap.covers(start), "Out of bounds"); | |
1077 // See comment in direct_allocated() about when objects should | |
1078 // be allocated live. | |
1079 if (_collectorState >= Marking) { | |
1080 // we already hold the marking bit map lock, taken in | |
1081 // the prologue | |
1082 if (par) { | |
1083 _markBitMap.par_mark(start); | |
1084 } else { | |
1085 _markBitMap.mark(start); | |
1086 } | |
1087 // We don't need to mark the object as uninitialized (as | |
1088 // in direct_allocated above) because this is being done with the | |
1089 // world stopped and the object will be initialized by the | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1090 // time the marking, precleaning or sweeping get to look at it. |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1091 // But see the code for copying objects into the CMS generation, |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1092 // where we need to ensure that concurrent readers of the |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1093 // block offset table are able to safely navigate a block that |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1094 // is in flux from being free to being allocated (and in |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1095 // transition while being copied into) and subsequently |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1096 // becoming a bona-fide object when the copy/promotion is complete. |
0 | 1097 assert(SafepointSynchronize::is_at_safepoint(), |
1098 "expect promotion only at safepoints"); | |
1099 | |
1100 if (_collectorState < Sweeping) { | |
1101 // Mark the appropriate cards in the modUnionTable, so that | |
1102 // this object gets scanned before the sweep. If this is | |
1103 // not done, CMS generation references in the object might | |
1104 // not get marked. | |
1105 // For the case of arrays, which are otherwise precisely | |
1106 // marked, we need to dirty the entire array, not just its head. | |
1107 if (is_obj_array) { | |
1108 // The [par_]mark_range() method expects mr.end() below to | |
1109 // be aligned to the granularity of a bit's representation | |
1110 // in the heap. In the case of the MUT below, that's a | |
1111 // card size. | |
1112 MemRegion mr(start, | |
1113 (HeapWord*)round_to((intptr_t)(start + obj_size), | |
1114 CardTableModRefBS::card_size /* bytes */)); | |
1115 if (par) { | |
1116 _modUnionTable.par_mark_range(mr); | |
1117 } else { | |
1118 _modUnionTable.mark_range(mr); | |
1119 } | |
1120 } else { // not an obj array; we can just mark the head | |
1121 if (par) { | |
1122 _modUnionTable.par_mark(start); | |
1123 } else { | |
1124 _modUnionTable.mark(start); | |
1125 } | |
1126 } | |
1127 } | |
1128 } | |
1129 } | |
1130 | |
1131 static inline size_t percent_of_space(Space* space, HeapWord* addr) | |
1132 { | |
1133 size_t delta = pointer_delta(addr, space->bottom()); | |
1134 return (size_t)(delta * 100.0 / (space->capacity() / HeapWordSize)); | |
1135 } | |
1136 | |
1137 void CMSCollector::icms_update_allocation_limits() | |
1138 { | |
1139 Generation* gen0 = GenCollectedHeap::heap()->get_gen(0); | |
1140 EdenSpace* eden = gen0->as_DefNewGeneration()->eden(); | |
1141 | |
1142 const unsigned int duty_cycle = stats().icms_update_duty_cycle(); | |
1143 if (CMSTraceIncrementalPacing) { | |
1144 stats().print(); | |
1145 } | |
1146 | |
1147 assert(duty_cycle <= 100, "invalid duty cycle"); | |
1148 if (duty_cycle != 0) { | |
1149 // The duty_cycle is a percentage between 0 and 100; convert to words and | |
1150 // then compute the offset from the endpoints of the space. | |
1151 size_t free_words = eden->free() / HeapWordSize; | |
1152 double free_words_dbl = (double)free_words; | |
1153 size_t duty_cycle_words = (size_t)(free_words_dbl * duty_cycle / 100.0); | |
1154 size_t offset_words = (free_words - duty_cycle_words) / 2; | |
1155 | |
1156 _icms_start_limit = eden->top() + offset_words; | |
1157 _icms_stop_limit = eden->end() - offset_words; | |
1158 | |
1159 // The limits may be adjusted (shifted to the right) by | |
1160 // CMSIncrementalOffset, to allow the application more mutator time after a | |
1161 // young gen gc (when all mutators were stopped) and before CMS starts and | |
1162 // takes away one or more cpus. | |
1163 if (CMSIncrementalOffset != 0) { | |
1164 double adjustment_dbl = free_words_dbl * CMSIncrementalOffset / 100.0; | |
1165 size_t adjustment = (size_t)adjustment_dbl; | |
1166 HeapWord* tmp_stop = _icms_stop_limit + adjustment; | |
1167 if (tmp_stop > _icms_stop_limit && tmp_stop < eden->end()) { | |
1168 _icms_start_limit += adjustment; | |
1169 _icms_stop_limit = tmp_stop; | |
1170 } | |
1171 } | |
1172 } | |
1173 if (duty_cycle == 0 || (_icms_start_limit == _icms_stop_limit)) { | |
1174 _icms_start_limit = _icms_stop_limit = eden->end(); | |
1175 } | |
1176 | |
1177 // Install the new start limit. | |
1178 eden->set_soft_end(_icms_start_limit); | |
1179 | |
1180 if (CMSTraceIncrementalMode) { | |
1181 gclog_or_tty->print(" icms alloc limits: " | |
1182 PTR_FORMAT "," PTR_FORMAT | |
1183 " (" SIZE_FORMAT "%%," SIZE_FORMAT "%%) ", | |
1184 _icms_start_limit, _icms_stop_limit, | |
1185 percent_of_space(eden, _icms_start_limit), | |
1186 percent_of_space(eden, _icms_stop_limit)); | |
1187 if (Verbose) { | |
1188 gclog_or_tty->print("eden: "); | |
1189 eden->print_on(gclog_or_tty); | |
1190 } | |
1191 } | |
1192 } | |
1193 | |
1194 // Any changes here should try to maintain the invariant | |
1195 // that if this method is called with _icms_start_limit | |
1196 // and _icms_stop_limit both NULL, then it should return NULL | |
1197 // and not notify the icms thread. | |
1198 HeapWord* | |
1199 CMSCollector::allocation_limit_reached(Space* space, HeapWord* top, | |
1200 size_t word_size) | |
1201 { | |
1202 // A start_limit equal to end() means the duty cycle is 0, so treat that as a | |
1203 // nop. | |
1204 if (CMSIncrementalMode && _icms_start_limit != space->end()) { | |
1205 if (top <= _icms_start_limit) { | |
1206 if (CMSTraceIncrementalMode) { | |
1207 space->print_on(gclog_or_tty); | |
1208 gclog_or_tty->stamp(); | |
1209 gclog_or_tty->print_cr(" start limit top=" PTR_FORMAT | |
1210 ", new limit=" PTR_FORMAT | |
1211 " (" SIZE_FORMAT "%%)", | |
1212 top, _icms_stop_limit, | |
1213 percent_of_space(space, _icms_stop_limit)); | |
1214 } | |
1215 ConcurrentMarkSweepThread::start_icms(); | |
1216 assert(top < _icms_stop_limit, "Tautology"); | |
1217 if (word_size < pointer_delta(_icms_stop_limit, top)) { | |
1218 return _icms_stop_limit; | |
1219 } | |
1220 | |
1221 // The allocation will cross both the _start and _stop limits, so do the | |
1222 // stop notification also and return end(). | |
1223 if (CMSTraceIncrementalMode) { | |
1224 space->print_on(gclog_or_tty); | |
1225 gclog_or_tty->stamp(); | |
1226 gclog_or_tty->print_cr(" +stop limit top=" PTR_FORMAT | |
1227 ", new limit=" PTR_FORMAT | |
1228 " (" SIZE_FORMAT "%%)", | |
1229 top, space->end(), | |
1230 percent_of_space(space, space->end())); | |
1231 } | |
1232 ConcurrentMarkSweepThread::stop_icms(); | |
1233 return space->end(); | |
1234 } | |
1235 | |
1236 if (top <= _icms_stop_limit) { | |
1237 if (CMSTraceIncrementalMode) { | |
1238 space->print_on(gclog_or_tty); | |
1239 gclog_or_tty->stamp(); | |
1240 gclog_or_tty->print_cr(" stop limit top=" PTR_FORMAT | |
1241 ", new limit=" PTR_FORMAT | |
1242 " (" SIZE_FORMAT "%%)", | |
1243 top, space->end(), | |
1244 percent_of_space(space, space->end())); | |
1245 } | |
1246 ConcurrentMarkSweepThread::stop_icms(); | |
1247 return space->end(); | |
1248 } | |
1249 | |
1250 if (CMSTraceIncrementalMode) { | |
1251 space->print_on(gclog_or_tty); | |
1252 gclog_or_tty->stamp(); | |
1253 gclog_or_tty->print_cr(" end limit top=" PTR_FORMAT | |
1254 ", new limit=" PTR_FORMAT, | |
1255 top, NULL); | |
1256 } | |
1257 } | |
1258 | |
1259 return NULL; | |
1260 } | |
1261 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
1262 oop ConcurrentMarkSweepGeneration::promote(oop obj, size_t obj_size) { |
0 | 1263 assert(obj_size == (size_t)obj->size(), "bad obj_size passed in"); |
1264 // allocate, copy and if necessary update promoinfo -- | |
1265 // delegate to underlying space. | |
1266 assert_lock_strong(freelistLock()); | |
1267 | |
1268 #ifndef PRODUCT | |
1269 if (Universe::heap()->promotion_should_fail()) { | |
1270 return NULL; | |
1271 } | |
1272 #endif // #ifndef PRODUCT | |
1273 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
1274 oop res = _cmsSpace->promote(obj, obj_size); |
0 | 1275 if (res == NULL) { |
1276 // expand and retry | |
1277 size_t s = _cmsSpace->expansionSpaceRequired(obj_size); // HeapWords | |
1278 expand(s*HeapWordSize, MinHeapDeltaBytes, | |
1279 CMSExpansionCause::_satisfy_promotion); | |
1280 // Since there's currently no next generation, we don't try to promote | |
1281 // into a more senior generation. | |
1282 assert(next_gen() == NULL, "assumption, based upon which no attempt " | |
1283 "is made to pass on a possibly failing " | |
1284 "promotion to next generation"); | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
1285 res = _cmsSpace->promote(obj, obj_size); |
0 | 1286 } |
1287 if (res != NULL) { | |
1288 // See comment in allocate() about when objects should | |
1289 // be allocated live. | |
1290 assert(obj->is_oop(), "Will dereference klass pointer below"); | |
1291 collector()->promoted(false, // Not parallel | |
1292 (HeapWord*)res, obj->is_objArray(), obj_size); | |
1293 // promotion counters | |
1294 NOT_PRODUCT( | |
1295 _numObjectsPromoted++; | |
1296 _numWordsPromoted += | |
1297 (int)(CompactibleFreeListSpace::adjustObjectSize(obj->size())); | |
1298 ) | |
1299 } | |
1300 return res; | |
1301 } | |
1302 | |
1303 | |
1304 HeapWord* | |
1305 ConcurrentMarkSweepGeneration::allocation_limit_reached(Space* space, | |
1306 HeapWord* top, | |
1307 size_t word_sz) | |
1308 { | |
1309 return collector()->allocation_limit_reached(space, top, word_sz); | |
1310 } | |
1311 | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1312 // IMPORTANT: Notes on object size recognition in CMS. |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1313 // --------------------------------------------------- |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1314 // A block of storage in the CMS generation is always in |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1315 // one of three states. A free block (FREE), an allocated |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1316 // object (OBJECT) whose size() method reports the correct size, |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1317 // and an intermediate state (TRANSIENT) in which its size cannot |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1318 // be accurately determined. |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1319 // STATE IDENTIFICATION: (32 bit and 64 bit w/o COOPS) |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1320 // ----------------------------------------------------- |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1321 // FREE: klass_word & 1 == 1; mark_word holds block size |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1322 // |
1777
179464550c7d
6983930: CMS: Various small cleanups ca September 2010
ysr
parents:
1720
diff
changeset
|
1323 // OBJECT: klass_word installed; klass_word != 0 && klass_word & 1 == 0; |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1324 // obj->size() computes correct size |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1325 // |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1326 // TRANSIENT: klass_word == 0; size is indeterminate until we become an OBJECT |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1327 // |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1328 // STATE IDENTIFICATION: (64 bit+COOPS) |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1329 // ------------------------------------ |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1330 // FREE: mark_word & CMS_FREE_BIT == 1; mark_word & ~CMS_FREE_BIT gives block_size |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1331 // |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1332 // OBJECT: klass_word installed; klass_word != 0; |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1333 // obj->size() computes correct size |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1334 // |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1335 // TRANSIENT: klass_word == 0; size is indeterminate until we become an OBJECT |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1336 // |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1337 // |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1338 // STATE TRANSITION DIAGRAM |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1339 // |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1340 // mut / parnew mut / parnew |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1341 // FREE --------------------> TRANSIENT ---------------------> OBJECT --| |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1342 // ^ | |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1343 // |------------------------ DEAD <------------------------------------| |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1344 // sweep mut |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1345 // |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1346 // While a block is in TRANSIENT state its size cannot be determined |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1347 // so readers will either need to come back later or stall until |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1348 // the size can be determined. Note that for the case of direct |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1349 // allocation, P-bits, when available, may be used to determine the |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1350 // size of an object that may not yet have been initialized. |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1351 |
0 | 1352 // Things to support parallel young-gen collection. |
1353 oop | |
1354 ConcurrentMarkSweepGeneration::par_promote(int thread_num, | |
1355 oop old, markOop m, | |
1356 size_t word_sz) { | |
1357 #ifndef PRODUCT | |
1358 if (Universe::heap()->promotion_should_fail()) { | |
1359 return NULL; | |
1360 } | |
1361 #endif // #ifndef PRODUCT | |
1362 | |
1363 CMSParGCThreadState* ps = _par_gc_thread_states[thread_num]; | |
1364 PromotionInfo* promoInfo = &ps->promo; | |
1365 // if we are tracking promotions, then first ensure space for | |
1366 // promotion (including spooling space for saving header if necessary). | |
1367 // then allocate and copy, then track promoted info if needed. | |
1368 // When tracking (see PromotionInfo::track()), the mark word may | |
1369 // be displaced and in this case restoration of the mark word | |
1370 // occurs in the (oop_since_save_marks_)iterate phase. | |
1371 if (promoInfo->tracking() && !promoInfo->ensure_spooling_space()) { | |
1372 // Out of space for allocating spooling buffers; | |
1373 // try expanding and allocating spooling buffers. | |
1374 if (!expand_and_ensure_spooling_space(promoInfo)) { | |
1375 return NULL; | |
1376 } | |
1377 } | |
1378 assert(promoInfo->has_spooling_space(), "Control point invariant"); | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1379 const size_t alloc_sz = CompactibleFreeListSpace::adjustObjectSize(word_sz); |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1380 HeapWord* obj_ptr = ps->lab.alloc(alloc_sz); |
0 | 1381 if (obj_ptr == NULL) { |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1382 obj_ptr = expand_and_par_lab_allocate(ps, alloc_sz); |
0 | 1383 if (obj_ptr == NULL) { |
1384 return NULL; | |
1385 } | |
1386 } | |
1387 oop obj = oop(obj_ptr); | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1388 OrderAccess::storestore(); |
187 | 1389 assert(obj->klass_or_null() == NULL, "Object should be uninitialized here."); |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
1390 assert(!((FreeChunk*)obj_ptr)->is_free(), "Error, block will look free but show wrong size"); |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1391 // IMPORTANT: See note on object initialization for CMS above. |
0 | 1392 // Otherwise, copy the object. Here we must be careful to insert the |
1393 // klass pointer last, since this marks the block as an allocated object. | |
187 | 1394 // Except with compressed oops it's the mark word. |
0 | 1395 HeapWord* old_ptr = (HeapWord*)old; |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1396 // Restore the mark word copied above. |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1397 obj->set_mark(m); |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1398 assert(obj->klass_or_null() == NULL, "Object should be uninitialized here."); |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
1399 assert(!((FreeChunk*)obj_ptr)->is_free(), "Error, block will look free but show wrong size"); |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1400 OrderAccess::storestore(); |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1401 |
12226
7944aba7ba41
8015107: NPG: Use consistent naming for metaspace concepts
ehelin
parents:
12112
diff
changeset
|
1402 if (UseCompressedClassPointers) { |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1403 // Copy gap missed by (aligned) header size calculation below |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1404 obj->set_klass_gap(old->klass_gap()); |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1405 } |
0 | 1406 if (word_sz > (size_t)oopDesc::header_size()) { |
1407 Copy::aligned_disjoint_words(old_ptr + oopDesc::header_size(), | |
1408 obj_ptr + oopDesc::header_size(), | |
1409 word_sz - oopDesc::header_size()); | |
1410 } | |
187 | 1411 |
0 | 1412 // Now we can track the promoted object, if necessary. We take care |
1521 | 1413 // to delay the transition from uninitialized to full object |
0 | 1414 // (i.e., insertion of klass pointer) until after, so that it |
1415 // atomically becomes a promoted object. | |
1416 if (promoInfo->tracking()) { | |
1417 promoInfo->track((PromotedObject*)obj, old->klass()); | |
1418 } | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1419 assert(obj->klass_or_null() == NULL, "Object should be uninitialized here."); |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
1420 assert(!((FreeChunk*)obj_ptr)->is_free(), "Error, block will look free but show wrong size"); |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1421 assert(old->is_oop(), "Will use and dereference old klass ptr below"); |
187 | 1422 |
1423 // Finally, install the klass pointer (this should be volatile). | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1424 OrderAccess::storestore(); |
0 | 1425 obj->set_klass(old->klass()); |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1426 // We should now be able to calculate the right size for this object |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1427 assert(obj->is_oop() && obj->size() == (int)word_sz, "Error, incorrect size computed for promoted object"); |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1428 |
0 | 1429 collector()->promoted(true, // parallel |
1430 obj_ptr, old->is_objArray(), word_sz); | |
1431 | |
1432 NOT_PRODUCT( | |
1716
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1433 Atomic::inc_ptr(&_numObjectsPromoted); |
be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
ysr
parents:
1704
diff
changeset
|
1434 Atomic::add_ptr(alloc_sz, &_numWordsPromoted); |
0 | 1435 ) |
1436 | |
1437 return obj; | |
1438 } | |
1439 | |
1440 void | |
1441 ConcurrentMarkSweepGeneration:: | |
1442 par_promote_alloc_undo(int thread_num, | |
1443 HeapWord* obj, size_t word_sz) { | |
1444 // CMS does not support promotion undo. | |
1445 ShouldNotReachHere(); | |
1446 } | |
1447 | |
1448 void | |
1449 ConcurrentMarkSweepGeneration:: | |
1450 par_promote_alloc_done(int thread_num) { | |
1451 CMSParGCThreadState* ps = _par_gc_thread_states[thread_num]; | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
1452 ps->lab.retire(thread_num); |
0 | 1453 } |
1454 | |
1455 void | |
1456 ConcurrentMarkSweepGeneration:: | |
1457 par_oop_since_save_marks_iterate_done(int thread_num) { | |
1458 CMSParGCThreadState* ps = _par_gc_thread_states[thread_num]; | |
1459 ParScanWithoutBarrierClosure* dummy_cl = NULL; | |
1460 ps->promo.promoted_oops_iterate_nv(dummy_cl); | |
1461 } | |
1462 | |
1463 bool ConcurrentMarkSweepGeneration::should_collect(bool full, | |
1464 size_t size, | |
1465 bool tlab) | |
1466 { | |
1467 // We allow a STW collection only if a full | |
1468 // collection was requested. | |
1469 return full || should_allocate(size, tlab); // FIX ME !!! | |
1470 // This and promotion failure handling are connected at the | |
1471 // hip and should be fixed by untying them. | |
1472 } | |
1473 | |
1474 bool CMSCollector::shouldConcurrentCollect() { | |
1475 if (_full_gc_requested) { | |
1476 if (Verbose && PrintGCDetails) { | |
1477 gclog_or_tty->print_cr("CMSCollector: collect because of explicit " | |
1520
bb843ebc7c55
6919638: CMS: ExplicitGCInvokesConcurrent misinteracts with gc locker
ysr
parents:
1518
diff
changeset
|
1478 " gc request (or gc_locker)"); |
0 | 1479 } |
1480 return true; | |
1481 } | |
1482 | |
1483 // For debugging purposes, change the type of collection. | |
1484 // If the rotation is not on the concurrent collection | |
1485 // type, don't start a concurrent collection. | |
1486 NOT_PRODUCT( | |
1487 if (RotateCMSCollectionTypes && | |
1488 (_cmsGen->debug_collection_type() != | |
1489 ConcurrentMarkSweepGeneration::Concurrent_collection_type)) { | |
1490 assert(_cmsGen->debug_collection_type() != | |
1491 ConcurrentMarkSweepGeneration::Unknown_collection_type, | |
1492 "Bad cms collection type"); | |
1493 return false; | |
1494 } | |
1495 ) | |
1496 | |
1497 FreelistLocker x(this); | |
1498 // ------------------------------------------------------------------ | |
1499 // Print out lots of information which affects the initiation of | |
1500 // a collection. | |
1501 if (PrintCMSInitiationStatistics && stats().valid()) { | |
1502 gclog_or_tty->print("CMSCollector shouldConcurrentCollect: "); | |
1503 gclog_or_tty->stamp(); | |
1504 gclog_or_tty->print_cr(""); | |
1505 stats().print_on(gclog_or_tty); | |
1506 gclog_or_tty->print_cr("time_until_cms_gen_full %3.7f", | |
1507 stats().time_until_cms_gen_full()); | |
1508 gclog_or_tty->print_cr("free="SIZE_FORMAT, _cmsGen->free()); | |
1509 gclog_or_tty->print_cr("contiguous_available="SIZE_FORMAT, | |
1510 _cmsGen->contiguous_available()); | |
1511 gclog_or_tty->print_cr("promotion_rate=%g", stats().promotion_rate()); | |
1512 gclog_or_tty->print_cr("cms_allocation_rate=%g", stats().cms_allocation_rate()); | |
1513 gclog_or_tty->print_cr("occupancy=%3.7f", _cmsGen->occupancy()); | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1514 gclog_or_tty->print_cr("initiatingOccupancy=%3.7f", _cmsGen->initiating_occupancy()); |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1515 gclog_or_tty->print_cr("metadata initialized %d", |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1516 MetaspaceGC::should_concurrent_collect()); |
0 | 1517 } |
1518 // ------------------------------------------------------------------ | |
1519 | |
1520 // If the estimated time to complete a cms collection (cms_duration()) | |
1521 // is less than the estimated time remaining until the cms generation | |
1522 // is full, start a collection. | |
1523 if (!UseCMSInitiatingOccupancyOnly) { | |
1524 if (stats().valid()) { | |
1525 if (stats().time_until_cms_start() == 0.0) { | |
1526 return true; | |
1527 } | |
1528 } else { | |
1529 // We want to conservatively collect somewhat early in order | |
1530 // to try and "bootstrap" our CMS/promotion statistics; | |
1531 // this branch will not fire after the first successful CMS | |
1532 // collection because the stats should then be valid. | |
1533 if (_cmsGen->occupancy() >= _bootstrap_occupancy) { | |
1534 if (Verbose && PrintGCDetails) { | |
1535 gclog_or_tty->print_cr( | |
1536 " CMSCollector: collect for bootstrapping statistics:" | |
1537 " occupancy = %f, boot occupancy = %f", _cmsGen->occupancy(), | |
1538 _bootstrap_occupancy); | |
1539 } | |
1540 return true; | |
1541 } | |
1542 } | |
1543 } | |
1544 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1545 // Otherwise, we start a collection cycle if |
0 | 1546 // old gen want a collection cycle started. Each may use |
1547 // an appropriate criterion for making this decision. | |
1548 // XXX We need to make sure that the gen expansion | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1549 // criterion dovetails well with this. XXX NEED TO FIX THIS |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1550 if (_cmsGen->should_concurrent_collect()) { |
0 | 1551 if (Verbose && PrintGCDetails) { |
1552 gclog_or_tty->print_cr("CMS old gen initiated"); | |
1553 } | |
1554 return true; | |
1555 } | |
1556 | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1557 // We start a collection if we believe an incremental collection may fail; |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1558 // this is not likely to be productive in practice because it's probably too |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1559 // late anyway. |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1560 GenCollectedHeap* gch = GenCollectedHeap::heap(); |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1561 assert(gch->collector_policy()->is_two_generation_policy(), |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1562 "You may want to check the correctness of the following"); |
1994
6cd6d394f280
7001033: assert(gch->gc_cause() == GCCause::_scavenge_alot || !gch->incremental_collection_failed())
ysr
parents:
1972
diff
changeset
|
1563 if (gch->incremental_collection_will_fail(true /* consult_young */)) { |
6cd6d394f280
7001033: assert(gch->gc_cause() == GCCause::_scavenge_alot || !gch->incremental_collection_failed())
ysr
parents:
1972
diff
changeset
|
1564 if (Verbose && PrintGCDetails) { |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1565 gclog_or_tty->print("CMSCollector: collect because incremental collection will fail "); |
0 | 1566 } |
1567 return true; | |
1568 } | |
1569 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1570 if (MetaspaceGC::should_concurrent_collect()) { |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1571 if (Verbose && PrintGCDetails) { |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1572 gclog_or_tty->print("CMSCollector: collect for metadata allocation "); |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1573 } |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1574 return true; |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1575 } |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1576 |
0 | 1577 return false; |
1578 } | |
1579 | |
10244
06ab37f08701
8013184: CMS: Call reset_after_compaction() only if a compaction has been done
jmasa
parents:
10243
diff
changeset
|
1580 void CMSCollector::set_did_compact(bool v) { _cmsGen->set_did_compact(v); } |
06ab37f08701
8013184: CMS: Call reset_after_compaction() only if a compaction has been done
jmasa
parents:
10243
diff
changeset
|
1581 |
0 | 1582 // Clear _expansion_cause fields of constituent generations |
1583 void CMSCollector::clear_expansion_cause() { | |
1584 _cmsGen->clear_expansion_cause(); | |
1585 } | |
1586 | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1587 // We should be conservative in starting a collection cycle. To |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1588 // start too eagerly runs the risk of collecting too often in the |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1589 // extreme. To collect too rarely falls back on full collections, |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1590 // which works, even if not optimum in terms of concurrent work. |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1591 // As a work around for too eagerly collecting, use the flag |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1592 // UseCMSInitiatingOccupancyOnly. This also has the advantage of |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1593 // giving the user an easily understandable way of controlling the |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1594 // collections. |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1595 // We want to start a new collection cycle if any of the following |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1596 // conditions hold: |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1597 // . our current occupancy exceeds the configured initiating occupancy |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1598 // for this generation, or |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1599 // . we recently needed to expand this space and have not, since that |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1600 // expansion, done a collection of this generation, or |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1601 // . the underlying space believes that it may be a good idea to initiate |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1602 // a concurrent collection (this may be based on criteria such as the |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1603 // following: the space uses linear allocation and linear allocation is |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1604 // going to fail, or there is believed to be excessive fragmentation in |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1605 // the generation, etc... or ... |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1606 // [.(currently done by CMSCollector::shouldConcurrentCollect() only for |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1607 // the case of the old generation; see CR 6543076): |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1608 // we may be approaching a point at which allocation requests may fail because |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1609 // we will be out of sufficient free space given allocation rate estimates.] |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1610 bool ConcurrentMarkSweepGeneration::should_concurrent_collect() const { |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1611 |
0 | 1612 assert_lock_strong(freelistLock()); |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1613 if (occupancy() > initiating_occupancy()) { |
0 | 1614 if (PrintGCDetails && Verbose) { |
1615 gclog_or_tty->print(" %s: collect because of occupancy %f / %f ", | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1616 short_name(), occupancy(), initiating_occupancy()); |
0 | 1617 } |
1618 return true; | |
1619 } | |
1620 if (UseCMSInitiatingOccupancyOnly) { | |
1621 return false; | |
1622 } | |
1623 if (expansion_cause() == CMSExpansionCause::_satisfy_allocation) { | |
1624 if (PrintGCDetails && Verbose) { | |
1625 gclog_or_tty->print(" %s: collect because expanded for allocation ", | |
1626 short_name()); | |
1627 } | |
1628 return true; | |
1629 } | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1630 if (_cmsSpace->should_concurrent_collect()) { |
0 | 1631 if (PrintGCDetails && Verbose) { |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
1632 gclog_or_tty->print(" %s: collect because cmsSpace says so ", |
0 | 1633 short_name()); |
1634 } | |
1635 return true; | |
1636 } | |
1637 return false; | |
1638 } | |
1639 | |
1640 void ConcurrentMarkSweepGeneration::collect(bool full, | |
1641 bool clear_all_soft_refs, | |
1642 size_t size, | |
1643 bool tlab) | |
1644 { | |
1645 collector()->collect(full, clear_all_soft_refs, size, tlab); | |
1646 } | |
1647 | |
1648 void CMSCollector::collect(bool full, | |
1649 bool clear_all_soft_refs, | |
1650 size_t size, | |
1651 bool tlab) | |
1652 { | |
1653 if (!UseCMSCollectionPassing && _collectorState > Idling) { | |
1654 // For debugging purposes skip the collection if the state | |
1655 // is not currently idle | |
1656 if (TraceCMSState) { | |
1657 gclog_or_tty->print_cr("Thread " INTPTR_FORMAT " skipped full:%d CMS state %d", | |
1658 Thread::current(), full, _collectorState); | |
1659 } | |
1660 return; | |
1661 } | |
1662 | |
1663 // The following "if" branch is present for defensive reasons. | |
1664 // In the current uses of this interface, it can be replaced with: | |
1665 // assert(!GC_locker.is_active(), "Can't be called otherwise"); | |
1666 // But I am not placing that assert here to allow future | |
1667 // generality in invoking this interface. | |
1668 if (GC_locker::is_active()) { | |
1669 // A consistency test for GC_locker | |
1670 assert(GC_locker::needs_gc(), "Should have been set already"); | |
1671 // Skip this foreground collection, instead | |
1672 // expanding the heap if necessary. | |
1673 // Need the free list locks for the call to free() in compute_new_size() | |
1674 compute_new_size(); | |
1675 return; | |
1676 } | |
1677 acquire_control_and_collect(full, clear_all_soft_refs); | |
1678 _full_gcs_since_conc_gc++; | |
1679 } | |
1680 | |
10405 | 1681 void CMSCollector::request_full_gc(unsigned int full_gc_count, GCCause::Cause cause) { |
0 | 1682 GenCollectedHeap* gch = GenCollectedHeap::heap(); |
1683 unsigned int gc_count = gch->total_full_collections(); | |
1684 if (gc_count == full_gc_count) { | |
1685 MutexLockerEx y(CGC_lock, Mutex::_no_safepoint_check_flag); | |
1686 _full_gc_requested = true; | |
10405 | 1687 _full_gc_cause = cause; |
0 | 1688 CGC_lock->notify(); // nudge CMS thread |
2365
a181f3a124dd
6987703: iCMS: Intermittent hang with gc/gctests/CallGC/CallGC01 and +ExplicitGCInvokesConcurrent
ysr
parents:
2226
diff
changeset
|
1689 } else { |
a181f3a124dd
6987703: iCMS: Intermittent hang with gc/gctests/CallGC/CallGC01 and +ExplicitGCInvokesConcurrent
ysr
parents:
2226
diff
changeset
|
1690 assert(gc_count > full_gc_count, "Error: causal loop"); |
0 | 1691 } |
1692 } | |
1693 | |
10405 | 1694 bool CMSCollector::is_external_interruption() { |
1695 GCCause::Cause cause = GenCollectedHeap::heap()->gc_cause(); | |
1696 return GCCause::is_user_requested_gc(cause) || | |
1697 GCCause::is_serviceability_requested_gc(cause); | |
1698 } | |
1699 | |
1700 void CMSCollector::report_concurrent_mode_interruption() { | |
1701 if (is_external_interruption()) { | |
1702 if (PrintGCDetails) { | |
1703 gclog_or_tty->print(" (concurrent mode interrupted)"); | |
1704 } | |
1705 } else { | |
1706 if (PrintGCDetails) { | |
1707 gclog_or_tty->print(" (concurrent mode failure)"); | |
1708 } | |
1709 _gc_tracer_cm->report_concurrent_mode_failure(); | |
1710 } | |
1711 } | |
1712 | |
0 | 1713 |
1714 // The foreground and background collectors need to coordinate in order | |
1715 // to make sure that they do not mutually interfere with CMS collections. | |
1716 // When a background collection is active, | |
1717 // the foreground collector may need to take over (preempt) and | |
1718 // synchronously complete an ongoing collection. Depending on the | |
1719 // frequency of the background collections and the heap usage | |
1720 // of the application, this preemption can be seldom or frequent. | |
1721 // There are only certain | |
1722 // points in the background collection that the "collection-baton" | |
1723 // can be passed to the foreground collector. | |
1724 // | |
1725 // The foreground collector will wait for the baton before | |
1726 // starting any part of the collection. The foreground collector | |
1727 // will only wait at one location. | |
1728 // | |
1729 // The background collector will yield the baton before starting a new | |
1730 // phase of the collection (e.g., before initial marking, marking from roots, | |
1731 // precleaning, final re-mark, sweep etc.) This is normally done at the head | |
1732 // of the loop which switches the phases. The background collector does some | |
1733 // of the phases (initial mark, final re-mark) with the world stopped. | |
1734 // Because of locking involved in stopping the world, | |
1735 // the foreground collector should not block waiting for the background | |
1736 // collector when it is doing a stop-the-world phase. The background | |
1737 // collector will yield the baton at an additional point just before | |
1738 // it enters a stop-the-world phase. Once the world is stopped, the | |
1739 // background collector checks the phase of the collection. If the | |
1740 // phase has not changed, it proceeds with the collection. If the | |
1741 // phase has changed, it skips that phase of the collection. See | |
1742 // the comments on the use of the Heap_lock in collect_in_background(). | |
1743 // | |
1744 // Variable used in baton passing. | |
1745 // _foregroundGCIsActive - Set to true by the foreground collector when | |
1746 // it wants the baton. The foreground clears it when it has finished | |
1747 // the collection. | |
1748 // _foregroundGCShouldWait - Set to true by the background collector | |
1749 // when it is running. The foreground collector waits while | |
1750 // _foregroundGCShouldWait is true. | |
1751 // CGC_lock - monitor used to protect access to the above variables | |
1752 // and to notify the foreground and background collectors. | |
1753 // _collectorState - current state of the CMS collection. | |
1754 // | |
1755 // The foreground collector | |
1756 // acquires the CGC_lock | |
1757 // sets _foregroundGCIsActive | |
1758 // waits on the CGC_lock for _foregroundGCShouldWait to be false | |
1759 // various locks acquired in preparation for the collection | |
1760 // are released so as not to block the background collector | |
1761 // that is in the midst of a collection | |
1762 // proceeds with the collection | |
1763 // clears _foregroundGCIsActive | |
1764 // returns | |
1765 // | |
1766 // The background collector in a loop iterating on the phases of the | |
1767 // collection | |
1768 // acquires the CGC_lock | |
1769 // sets _foregroundGCShouldWait | |
1770 // if _foregroundGCIsActive is set | |
1771 // clears _foregroundGCShouldWait, notifies _CGC_lock | |
1772 // waits on _CGC_lock for _foregroundGCIsActive to become false | |
1773 // and exits the loop. | |
1774 // otherwise | |
1775 // proceed with that phase of the collection | |
1776 // if the phase is a stop-the-world phase, | |
1777 // yield the baton once more just before enqueueing | |
1778 // the stop-world CMS operation (executed by the VM thread). | |
1779 // returns after all phases of the collection are done | |
1780 // | |
1781 | |
1782 void CMSCollector::acquire_control_and_collect(bool full, | |
1783 bool clear_all_soft_refs) { | |
1784 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); | |
1785 assert(!Thread::current()->is_ConcurrentGC_thread(), | |
1786 "shouldn't try to acquire control from self!"); | |
1787 | |
1788 // Start the protocol for acquiring control of the | |
1789 // collection from the background collector (aka CMS thread). | |
1790 assert(ConcurrentMarkSweepThread::vm_thread_has_cms_token(), | |
1791 "VM thread should have CMS token"); | |
1792 // Remember the possibly interrupted state of an ongoing | |
1793 // concurrent collection | |
1794 CollectorState first_state = _collectorState; | |
1795 | |
1796 // Signal to a possibly ongoing concurrent collection that | |
1797 // we want to do a foreground collection. | |
1798 _foregroundGCIsActive = true; | |
1799 | |
1800 // Disable incremental mode during a foreground collection. | |
1801 ICMSDisabler icms_disabler; | |
1802 | |
1803 // release locks and wait for a notify from the background collector | |
1804 // releasing the locks in only necessary for phases which | |
1805 // do yields to improve the granularity of the collection. | |
1806 assert_lock_strong(bitMapLock()); | |
1807 // We need to lock the Free list lock for the space that we are | |
1808 // currently collecting. | |
1809 assert(haveFreelistLocks(), "Must be holding free list locks"); | |
1810 bitMapLock()->unlock(); | |
1811 releaseFreelistLocks(); | |
1812 { | |
1813 MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag); | |
1814 if (_foregroundGCShouldWait) { | |
1815 // We are going to be waiting for action for the CMS thread; | |
1816 // it had better not be gone (for instance at shutdown)! | |
1817 assert(ConcurrentMarkSweepThread::cmst() != NULL, | |
1818 "CMS thread must be running"); | |
1819 // Wait here until the background collector gives us the go-ahead | |
1820 ConcurrentMarkSweepThread::clear_CMS_flag( | |
1821 ConcurrentMarkSweepThread::CMS_vm_has_token); // release token | |
1822 // Get a possibly blocked CMS thread going: | |
1823 // Note that we set _foregroundGCIsActive true above, | |
1824 // without protection of the CGC_lock. | |
1825 CGC_lock->notify(); | |
1826 assert(!ConcurrentMarkSweepThread::vm_thread_wants_cms_token(), | |
1827 "Possible deadlock"); | |
1828 while (_foregroundGCShouldWait) { | |
1829 // wait for notification | |
1830 CGC_lock->wait(Mutex::_no_safepoint_check_flag); | |
1831 // Possibility of delay/starvation here, since CMS token does | |
1832 // not know to give priority to VM thread? Actually, i think | |
1833 // there wouldn't be any delay/starvation, but the proof of | |
1834 // that "fact" (?) appears non-trivial. XXX 20011219YSR | |
1835 } | |
1836 ConcurrentMarkSweepThread::set_CMS_flag( | |
1837 ConcurrentMarkSweepThread::CMS_vm_has_token); | |
1838 } | |
1839 } | |
1840 // The CMS_token is already held. Get back the other locks. | |
1841 assert(ConcurrentMarkSweepThread::vm_thread_has_cms_token(), | |
1842 "VM thread should have CMS token"); | |
1843 getFreelistLocks(); | |
1844 bitMapLock()->lock_without_safepoint_check(); | |
1845 if (TraceCMSState) { | |
1846 gclog_or_tty->print_cr("CMS foreground collector has asked for control " | |
1847 INTPTR_FORMAT " with first state %d", Thread::current(), first_state); | |
1848 gclog_or_tty->print_cr(" gets control with state %d", _collectorState); | |
1849 } | |
1850 | |
1851 // Check if we need to do a compaction, or if not, whether | |
1852 // we need to start the mark-sweep from scratch. | |
1853 bool should_compact = false; | |
1854 bool should_start_over = false; | |
1855 decide_foreground_collection_type(clear_all_soft_refs, | |
1856 &should_compact, &should_start_over); | |
1857 | |
1858 NOT_PRODUCT( | |
1859 if (RotateCMSCollectionTypes) { | |
1860 if (_cmsGen->debug_collection_type() == | |
1861 ConcurrentMarkSweepGeneration::MSC_foreground_collection_type) { | |
1862 should_compact = true; | |
1863 } else if (_cmsGen->debug_collection_type() == | |
1864 ConcurrentMarkSweepGeneration::MS_foreground_collection_type) { | |
1865 should_compact = false; | |
1866 } | |
1867 } | |
1868 ) | |
1869 | |
10405 | 1870 if (first_state > Idling) { |
1871 report_concurrent_mode_interruption(); | |
0 | 1872 } |
1873 | |
10244
06ab37f08701
8013184: CMS: Call reset_after_compaction() only if a compaction has been done
jmasa
parents:
10243
diff
changeset
|
1874 set_did_compact(should_compact); |
0 | 1875 if (should_compact) { |
1876 // If the collection is being acquired from the background | |
1877 // collector, there may be references on the discovered | |
1878 // references lists that have NULL referents (being those | |
1879 // that were concurrently cleared by a mutator) or | |
1880 // that are no longer active (having been enqueued concurrently | |
1881 // by the mutator). | |
1882 // Scrub the list of those references because Mark-Sweep-Compact | |
1883 // code assumes referents are not NULL and that all discovered | |
1884 // Reference objects are active. | |
1885 ref_processor()->clean_up_discovered_references(); | |
1886 | |
10405 | 1887 if (first_state > Idling) { |
1888 save_heap_summary(); | |
1889 } | |
1890 | |
0 | 1891 do_compaction_work(clear_all_soft_refs); |
1892 | |
1893 // Has the GC time limit been exceeded? | |
1387
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1894 DefNewGeneration* young_gen = _young_gen->as_DefNewGeneration(); |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1895 size_t max_eden_size = young_gen->max_capacity() - |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1896 young_gen->to()->capacity() - |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1897 young_gen->from()->capacity(); |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1898 GenCollectedHeap* gch = GenCollectedHeap::heap(); |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1899 GCCause::Cause gc_cause = gch->gc_cause(); |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1900 size_policy()->check_gc_overhead_limit(_young_gen->used(), |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1901 young_gen->eden()->used(), |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1902 _cmsGen->max_capacity(), |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1903 max_eden_size, |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1904 full, |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1905 gc_cause, |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
1906 gch->collector_policy()); |
0 | 1907 } else { |
1908 do_mark_sweep_work(clear_all_soft_refs, first_state, | |
1909 should_start_over); | |
1910 } | |
1911 // Reset the expansion cause, now that we just completed | |
1912 // a collection cycle. | |
1913 clear_expansion_cause(); | |
1914 _foregroundGCIsActive = false; | |
1915 return; | |
1916 } | |
1917 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1918 // Resize the tenured generation |
0 | 1919 // after obtaining the free list locks for the |
1920 // two generations. | |
1921 void CMSCollector::compute_new_size() { | |
1922 assert_locked_or_safepoint(Heap_lock); | |
1923 FreelistLocker z(this); | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
1924 MetaspaceGC::compute_new_size(); |
9072
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
1925 _cmsGen->compute_new_size_free_list(); |
0 | 1926 } |
1927 | |
1928 // A work method used by foreground collection to determine | |
1929 // what type of collection (compacting or not, continuing or fresh) | |
1930 // it should do. | |
1931 // NOTE: the intent is to make UseCMSCompactAtFullCollection | |
1932 // and CMSCompactWhenClearAllSoftRefs the default in the future | |
1933 // and do away with the flags after a suitable period. | |
1934 void CMSCollector::decide_foreground_collection_type( | |
1935 bool clear_all_soft_refs, bool* should_compact, | |
1936 bool* should_start_over) { | |
1937 // Normally, we'll compact only if the UseCMSCompactAtFullCollection | |
1938 // flag is set, and we have either requested a System.gc() or | |
1939 // the number of full gc's since the last concurrent cycle | |
1940 // has exceeded the threshold set by CMSFullGCsBeforeCompaction, | |
1941 // or if an incremental collection has failed | |
1942 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
1943 assert(gch->collector_policy()->is_two_generation_policy(), | |
1944 "You may want to check the correctness of the following"); | |
1945 // Inform cms gen if this was due to partial collection failing. | |
1946 // The CMS gen may use this fact to determine its expansion policy. | |
1994
6cd6d394f280
7001033: assert(gch->gc_cause() == GCCause::_scavenge_alot || !gch->incremental_collection_failed())
ysr
parents:
1972
diff
changeset
|
1947 if (gch->incremental_collection_will_fail(false /* don't consult_young */)) { |
0 | 1948 assert(!_cmsGen->incremental_collection_failed(), |
1949 "Should have been noticed, reacted to and cleared"); | |
1950 _cmsGen->set_incremental_collection_failed(); | |
1951 } | |
1952 *should_compact = | |
1953 UseCMSCompactAtFullCollection && | |
1954 ((_full_gcs_since_conc_gc >= CMSFullGCsBeforeCompaction) || | |
1955 GCCause::is_user_requested_gc(gch->gc_cause()) || | |
1994
6cd6d394f280
7001033: assert(gch->gc_cause() == GCCause::_scavenge_alot || !gch->incremental_collection_failed())
ysr
parents:
1972
diff
changeset
|
1956 gch->incremental_collection_will_fail(true /* consult_young */)); |
0 | 1957 *should_start_over = false; |
1958 if (clear_all_soft_refs && !*should_compact) { | |
1959 // We are about to do a last ditch collection attempt | |
1960 // so it would normally make sense to do a compaction | |
1961 // to reclaim as much space as possible. | |
1962 if (CMSCompactWhenClearAllSoftRefs) { | |
1963 // Default: The rationale is that in this case either | |
1964 // we are past the final marking phase, in which case | |
1965 // we'd have to start over, or so little has been done | |
1966 // that there's little point in saving that work. Compaction | |
1967 // appears to be the sensible choice in either case. | |
1968 *should_compact = true; | |
1969 } else { | |
1970 // We have been asked to clear all soft refs, but not to | |
1971 // compact. Make sure that we aren't past the final checkpoint | |
1972 // phase, for that is where we process soft refs. If we are already | |
1973 // past that phase, we'll need to redo the refs discovery phase and | |
1974 // if necessary clear soft refs that weren't previously | |
1975 // cleared. We do so by remembering the phase in which | |
1976 // we came in, and if we are past the refs processing | |
1977 // phase, we'll choose to just redo the mark-sweep | |
1978 // collection from scratch. | |
1979 if (_collectorState > FinalMarking) { | |
1980 // We are past the refs processing phase; | |
1981 // start over and do a fresh synchronous CMS cycle | |
1982 _collectorState = Resetting; // skip to reset to start new cycle | |
1983 reset(false /* == !asynch */); | |
1984 *should_start_over = true; | |
1985 } // else we can continue a possibly ongoing current cycle | |
1986 } | |
1987 } | |
1988 } | |
1989 | |
1990 // A work method used by the foreground collector to do | |
1991 // a mark-sweep-compact. | |
1992 void CMSCollector::do_compaction_work(bool clear_all_soft_refs) { | |
1993 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
10405 | 1994 |
1995 STWGCTimer* gc_timer = GenMarkSweep::gc_timer(); | |
13400
86e6d691f2e1
8028128: Add a type safe alternative for working with counter based data
mgronlun
parents:
13064
diff
changeset
|
1996 gc_timer->register_gc_start(); |
10405 | 1997 |
1998 SerialOldTracer* gc_tracer = GenMarkSweep::gc_tracer(); | |
1999 gc_tracer->report_gc_start(gch->gc_cause(), gc_timer->gc_start()); | |
2000 | |
2001 GCTraceTime t("CMS:MSC ", PrintGCDetails && Verbose, true, NULL); | |
0 | 2002 if (PrintGC && Verbose && !(GCCause::is_user_requested_gc(gch->gc_cause()))) { |
2003 gclog_or_tty->print_cr("Compact ConcurrentMarkSweepGeneration after %d " | |
2004 "collections passed to foreground collector", _full_gcs_since_conc_gc); | |
2005 } | |
2006 | |
2007 // Sample collection interval time and reset for collection pause. | |
2008 if (UseAdaptiveSizePolicy) { | |
2009 size_policy()->msc_collection_begin(); | |
2010 } | |
2011 | |
2012 // Temporarily widen the span of the weak reference processing to | |
2013 // the entire heap. | |
2014 MemRegion new_span(GenCollectedHeap::heap()->reserved_region()); | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
2015 ReferenceProcessorSpanMutator rp_mut_span(ref_processor(), new_span); |
0 | 2016 // Temporarily, clear the "is_alive_non_header" field of the |
2017 // reference processor. | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
2018 ReferenceProcessorIsAliveMutator rp_mut_closure(ref_processor(), NULL); |
0 | 2019 // Temporarily make reference _processing_ single threaded (non-MT). |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
2020 ReferenceProcessorMTProcMutator rp_mut_mt_processing(ref_processor(), false); |
0 | 2021 // Temporarily make refs discovery atomic |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
2022 ReferenceProcessorAtomicMutator rp_mut_atomic(ref_processor(), true); |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
2023 // Temporarily make reference _discovery_ single threaded (non-MT) |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
2024 ReferenceProcessorMTDiscoveryMutator rp_mut_discovery(ref_processor(), false); |
0 | 2025 |
2026 ref_processor()->set_enqueuing_is_done(false); | |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3827
diff
changeset
|
2027 ref_processor()->enable_discovery(false /*verify_disabled*/, false /*check_no_refs*/); |
457
27a80744a83b
6778647: snap(), snap_policy() should be renamed setup(), setup_policy()
ysr
parents:
453
diff
changeset
|
2028 ref_processor()->setup_policy(clear_all_soft_refs); |
0 | 2029 // If an asynchronous collection finishes, the _modUnionTable is |
2030 // all clear. If we are assuming the collection from an asynchronous | |
2031 // collection, clear the _modUnionTable. | |
2032 assert(_collectorState != Idling || _modUnionTable.isAllClear(), | |
2033 "_modUnionTable should be clear if the baton was not passed"); | |
2034 _modUnionTable.clear_all(); | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2035 assert(_collectorState != Idling || _ct->klass_rem_set()->mod_union_is_clear(), |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2036 "mod union for klasses should be clear if the baton was passed"); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2037 _ct->klass_rem_set()->clear_mod_union(); |
0 | 2038 |
2039 // We must adjust the allocation statistics being maintained | |
2040 // in the free list space. We do so by reading and clearing | |
2041 // the sweep timer and updating the block flux rate estimates below. | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2042 assert(!_intra_sweep_timer.is_active(), "_intra_sweep_timer should be inactive"); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2043 if (_inter_sweep_timer.is_active()) { |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2044 _inter_sweep_timer.stop(); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2045 // Note that we do not use this sample to update the _inter_sweep_estimate. |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2046 _cmsGen->cmsSpace()->beginSweepFLCensus((float)(_inter_sweep_timer.seconds()), |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2047 _inter_sweep_estimate.padded_average(), |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2048 _intra_sweep_estimate.padded_average()); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2049 } |
0 | 2050 |
2051 GenMarkSweep::invoke_at_safepoint(_cmsGen->level(), | |
2052 ref_processor(), clear_all_soft_refs); | |
2053 #ifdef ASSERT | |
2054 CompactibleFreeListSpace* cms_space = _cmsGen->cmsSpace(); | |
2055 size_t free_size = cms_space->free(); | |
2056 assert(free_size == | |
2057 pointer_delta(cms_space->end(), cms_space->compaction_top()) | |
2058 * HeapWordSize, | |
2059 "All the free space should be compacted into one chunk at top"); | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
2060 assert(cms_space->dictionary()->total_chunk_size( |
0 | 2061 debug_only(cms_space->freelistLock())) == 0 || |
2062 cms_space->totalSizeInIndexedFreeLists() == 0, | |
2063 "All the free space should be in a single chunk"); | |
2064 size_t num = cms_space->totalCount(); | |
2065 assert((free_size == 0 && num == 0) || | |
2066 (free_size > 0 && (num == 1 || num == 2)), | |
2067 "There should be at most 2 free chunks after compaction"); | |
2068 #endif // ASSERT | |
2069 _collectorState = Resetting; | |
2070 assert(_restart_addr == NULL, | |
2071 "Should have been NULL'd before baton was passed"); | |
2072 reset(false /* == !asynch */); | |
2073 _cmsGen->reset_after_compaction(); | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
2074 _concurrent_cycles_since_last_unload = 0; |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
2075 |
0 | 2076 // Clear any data recorded in the PLAB chunk arrays. |
2077 if (_survivor_plab_array != NULL) { | |
2078 reset_survivor_plab_arrays(); | |
2079 } | |
2080 | |
2081 // Adjust the per-size allocation stats for the next epoch. | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2082 _cmsGen->cmsSpace()->endSweepFLCensus(sweep_count() /* fake */); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2083 // Restart the "inter sweep timer" for the next epoch. |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2084 _inter_sweep_timer.reset(); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2085 _inter_sweep_timer.start(); |
0 | 2086 |
2087 // Sample collection pause time and reset for collection interval. | |
2088 if (UseAdaptiveSizePolicy) { | |
2089 size_policy()->msc_collection_end(gch->gc_cause()); | |
2090 } | |
2091 | |
13400
86e6d691f2e1
8028128: Add a type safe alternative for working with counter based data
mgronlun
parents:
13064
diff
changeset
|
2092 gc_timer->register_gc_end(); |
10405 | 2093 |
2094 gc_tracer->report_gc_end(gc_timer->gc_end(), gc_timer->time_partitions()); | |
2095 | |
0 | 2096 // For a mark-sweep-compact, compute_new_size() will be called |
2097 // in the heap's do_collection() method. | |
2098 } | |
2099 | |
2100 // A work method used by the foreground collector to do | |
2101 // a mark-sweep, after taking over from a possibly on-going | |
2102 // concurrent mark-sweep collection. | |
2103 void CMSCollector::do_mark_sweep_work(bool clear_all_soft_refs, | |
2104 CollectorState first_state, bool should_start_over) { | |
2105 if (PrintGC && Verbose) { | |
2106 gclog_or_tty->print_cr("Pass concurrent collection to foreground " | |
2107 "collector with count %d", | |
2108 _full_gcs_since_conc_gc); | |
2109 } | |
2110 switch (_collectorState) { | |
2111 case Idling: | |
2112 if (first_state == Idling || should_start_over) { | |
2113 // The background GC was not active, or should | |
2114 // restarted from scratch; start the cycle. | |
2115 _collectorState = InitialMarking; | |
2116 } | |
2117 // If first_state was not Idling, then a background GC | |
2118 // was in progress and has now finished. No need to do it | |
2119 // again. Leave the state as Idling. | |
2120 break; | |
2121 case Precleaning: | |
2122 // In the foreground case don't do the precleaning since | |
2123 // it is not done concurrently and there is extra work | |
2124 // required. | |
2125 _collectorState = FinalMarking; | |
2126 } | |
10405 | 2127 collect_in_foreground(clear_all_soft_refs, GenCollectedHeap::heap()->gc_cause()); |
0 | 2128 |
2129 // For a mark-sweep, compute_new_size() will be called | |
2130 // in the heap's do_collection() method. | |
2131 } | |
2132 | |
2133 | |
11973
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2134 void CMSCollector::print_eden_and_survivor_chunk_arrays() { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2135 DefNewGeneration* dng = _young_gen->as_DefNewGeneration(); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2136 EdenSpace* eden_space = dng->eden(); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2137 ContiguousSpace* from_space = dng->from(); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2138 ContiguousSpace* to_space = dng->to(); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2139 // Eden |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2140 if (_eden_chunk_array != NULL) { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2141 gclog_or_tty->print_cr("eden " PTR_FORMAT "-" PTR_FORMAT "-" PTR_FORMAT "(" SIZE_FORMAT ")", |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2142 eden_space->bottom(), eden_space->top(), |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2143 eden_space->end(), eden_space->capacity()); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2144 gclog_or_tty->print_cr("_eden_chunk_index=" SIZE_FORMAT ", " |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2145 "_eden_chunk_capacity=" SIZE_FORMAT, |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2146 _eden_chunk_index, _eden_chunk_capacity); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2147 for (size_t i = 0; i < _eden_chunk_index; i++) { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2148 gclog_or_tty->print_cr("_eden_chunk_array[" SIZE_FORMAT "]=" PTR_FORMAT, |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2149 i, _eden_chunk_array[i]); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2150 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2151 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2152 // Survivor |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2153 if (_survivor_chunk_array != NULL) { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2154 gclog_or_tty->print_cr("survivor " PTR_FORMAT "-" PTR_FORMAT "-" PTR_FORMAT "(" SIZE_FORMAT ")", |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2155 from_space->bottom(), from_space->top(), |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2156 from_space->end(), from_space->capacity()); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2157 gclog_or_tty->print_cr("_survivor_chunk_index=" SIZE_FORMAT ", " |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2158 "_survivor_chunk_capacity=" SIZE_FORMAT, |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2159 _survivor_chunk_index, _survivor_chunk_capacity); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2160 for (size_t i = 0; i < _survivor_chunk_index; i++) { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2161 gclog_or_tty->print_cr("_survivor_chunk_array[" SIZE_FORMAT "]=" PTR_FORMAT, |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2162 i, _survivor_chunk_array[i]); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2163 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2164 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2165 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
2166 |
0 | 2167 void CMSCollector::getFreelistLocks() const { |
2168 // Get locks for all free lists in all generations that this | |
2169 // collector is responsible for | |
2170 _cmsGen->freelistLock()->lock_without_safepoint_check(); | |
2171 } | |
2172 | |
2173 void CMSCollector::releaseFreelistLocks() const { | |
2174 // Release locks for all free lists in all generations that this | |
2175 // collector is responsible for | |
2176 _cmsGen->freelistLock()->unlock(); | |
2177 } | |
2178 | |
2179 bool CMSCollector::haveFreelistLocks() const { | |
2180 // Check locks for all free lists in all generations that this | |
2181 // collector is responsible for | |
2182 assert_lock_strong(_cmsGen->freelistLock()); | |
2183 PRODUCT_ONLY(ShouldNotReachHere()); | |
2184 return true; | |
2185 } | |
2186 | |
2187 // A utility class that is used by the CMS collector to | |
2188 // temporarily "release" the foreground collector from its | |
2189 // usual obligation to wait for the background collector to | |
2190 // complete an ongoing phase before proceeding. | |
2191 class ReleaseForegroundGC: public StackObj { | |
2192 private: | |
2193 CMSCollector* _c; | |
2194 public: | |
2195 ReleaseForegroundGC(CMSCollector* c) : _c(c) { | |
2196 assert(_c->_foregroundGCShouldWait, "Else should not need to call"); | |
2197 MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag); | |
2198 // allow a potentially blocked foreground collector to proceed | |
2199 _c->_foregroundGCShouldWait = false; | |
2200 if (_c->_foregroundGCIsActive) { | |
2201 CGC_lock->notify(); | |
2202 } | |
2203 assert(!ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
2204 "Possible deadlock"); | |
2205 } | |
2206 | |
2207 ~ReleaseForegroundGC() { | |
2208 assert(!_c->_foregroundGCShouldWait, "Usage protocol violation?"); | |
2209 MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag); | |
2210 _c->_foregroundGCShouldWait = true; | |
2211 } | |
2212 }; | |
2213 | |
2214 // There are separate collect_in_background and collect_in_foreground because of | |
2215 // the different locking requirements of the background collector and the | |
2216 // foreground collector. There was originally an attempt to share | |
2217 // one "collect" method between the background collector and the foreground | |
2218 // collector but the if-then-else required made it cleaner to have | |
2219 // separate methods. | |
10405 | 2220 void CMSCollector::collect_in_background(bool clear_all_soft_refs, GCCause::Cause cause) { |
0 | 2221 assert(Thread::current()->is_ConcurrentGC_thread(), |
2222 "A CMS asynchronous collection is only allowed on a CMS thread."); | |
2223 | |
2224 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
2225 { | |
2226 bool safepoint_check = Mutex::_no_safepoint_check_flag; | |
2227 MutexLockerEx hl(Heap_lock, safepoint_check); | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
2228 FreelistLocker fll(this); |
0 | 2229 MutexLockerEx x(CGC_lock, safepoint_check); |
2230 if (_foregroundGCIsActive || !UseAsyncConcMarkSweepGC) { | |
2231 // The foreground collector is active or we're | |
2232 // not using asynchronous collections. Skip this | |
2233 // background collection. | |
2234 assert(!_foregroundGCShouldWait, "Should be clear"); | |
2235 return; | |
2236 } else { | |
2237 assert(_collectorState == Idling, "Should be idling before start."); | |
2238 _collectorState = InitialMarking; | |
10405 | 2239 register_gc_start(cause); |
0 | 2240 // Reset the expansion cause, now that we are about to begin |
2241 // a new cycle. | |
2242 clear_expansion_cause(); | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2243 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2244 // Clear the MetaspaceGC flag since a concurrent collection |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2245 // is starting but also clear it after the collection. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2246 MetaspaceGC::set_should_concurrent_collect(false); |
0 | 2247 } |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
2248 // Decide if we want to enable class unloading as part of the |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
2249 // ensuing concurrent GC cycle. |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
2250 update_should_unload_classes(); |
0 | 2251 _full_gc_requested = false; // acks all outstanding full gc requests |
10405 | 2252 _full_gc_cause = GCCause::_no_gc; |
0 | 2253 // Signal that we are about to start a collection |
2254 gch->increment_total_full_collections(); // ... starting a collection cycle | |
2255 _collection_count_start = gch->total_full_collections(); | |
2256 } | |
2257 | |
2258 // Used for PrintGC | |
2259 size_t prev_used; | |
2260 if (PrintGC && Verbose) { | |
2261 prev_used = _cmsGen->used(); // XXXPERM | |
2262 } | |
2263 | |
2264 // The change of the collection state is normally done at this level; | |
2265 // the exceptions are phases that are executed while the world is | |
2266 // stopped. For those phases the change of state is done while the | |
2267 // world is stopped. For baton passing purposes this allows the | |
2268 // background collector to finish the phase and change state atomically. | |
2269 // The foreground collector cannot wait on a phase that is done | |
2270 // while the world is stopped because the foreground collector already | |
2271 // has the world stopped and would deadlock. | |
2272 while (_collectorState != Idling) { | |
2273 if (TraceCMSState) { | |
2274 gclog_or_tty->print_cr("Thread " INTPTR_FORMAT " in CMS state %d", | |
2275 Thread::current(), _collectorState); | |
2276 } | |
2277 // The foreground collector | |
2278 // holds the Heap_lock throughout its collection. | |
2279 // holds the CMS token (but not the lock) | |
2280 // except while it is waiting for the background collector to yield. | |
2281 // | |
2282 // The foreground collector should be blocked (not for long) | |
2283 // if the background collector is about to start a phase | |
2284 // executed with world stopped. If the background | |
2285 // collector has already started such a phase, the | |
2286 // foreground collector is blocked waiting for the | |
2287 // Heap_lock. The stop-world phases (InitialMarking and FinalMarking) | |
2288 // are executed in the VM thread. | |
2289 // | |
2290 // The locking order is | |
2291 // PendingListLock (PLL) -- if applicable (FinalMarking) | |
2292 // Heap_lock (both this & PLL locked in VM_CMS_Operation::prologue()) | |
2293 // CMS token (claimed in | |
2294 // stop_world_and_do() --> | |
2295 // safepoint_synchronize() --> | |
2296 // CMSThread::synchronize()) | |
2297 | |
2298 { | |
2299 // Check if the FG collector wants us to yield. | |
2300 CMSTokenSync x(true); // is cms thread | |
2301 if (waitForForegroundGC()) { | |
2302 // We yielded to a foreground GC, nothing more to be | |
2303 // done this round. | |
2304 assert(_foregroundGCShouldWait == false, "We set it to false in " | |
2305 "waitForForegroundGC()"); | |
2306 if (TraceCMSState) { | |
2307 gclog_or_tty->print_cr("CMS Thread " INTPTR_FORMAT | |
2308 " exiting collection CMS state %d", | |
2309 Thread::current(), _collectorState); | |
2310 } | |
2311 return; | |
2312 } else { | |
2313 // The background collector can run but check to see if the | |
2314 // foreground collector has done a collection while the | |
2315 // background collector was waiting to get the CGC_lock | |
2316 // above. If yes, break so that _foregroundGCShouldWait | |
2317 // is cleared before returning. | |
2318 if (_collectorState == Idling) { | |
2319 break; | |
2320 } | |
2321 } | |
2322 } | |
2323 | |
2324 assert(_foregroundGCShouldWait, "Foreground collector, if active, " | |
2325 "should be waiting"); | |
2326 | |
2327 switch (_collectorState) { | |
2328 case InitialMarking: | |
2329 { | |
2330 ReleaseForegroundGC x(this); | |
2331 stats().record_cms_begin(); | |
2332 VM_CMS_Initial_Mark initial_mark_op(this); | |
2333 VMThread::execute(&initial_mark_op); | |
2334 } | |
2335 // The collector state may be any legal state at this point | |
2336 // since the background collector may have yielded to the | |
2337 // foreground collector. | |
2338 break; | |
2339 case Marking: | |
2340 // initial marking in checkpointRootsInitialWork has been completed | |
2341 if (markFromRoots(true)) { // we were successful | |
2342 assert(_collectorState == Precleaning, "Collector state should " | |
2343 "have changed"); | |
2344 } else { | |
2345 assert(_foregroundGCIsActive, "Internal state inconsistency"); | |
2346 } | |
2347 break; | |
2348 case Precleaning: | |
2349 if (UseAdaptiveSizePolicy) { | |
2350 size_policy()->concurrent_precleaning_begin(); | |
2351 } | |
2352 // marking from roots in markFromRoots has been completed | |
2353 preclean(); | |
2354 if (UseAdaptiveSizePolicy) { | |
2355 size_policy()->concurrent_precleaning_end(); | |
2356 } | |
2357 assert(_collectorState == AbortablePreclean || | |
2358 _collectorState == FinalMarking, | |
2359 "Collector state should have changed"); | |
2360 break; | |
2361 case AbortablePreclean: | |
2362 if (UseAdaptiveSizePolicy) { | |
2363 size_policy()->concurrent_phases_resume(); | |
2364 } | |
2365 abortable_preclean(); | |
2366 if (UseAdaptiveSizePolicy) { | |
2367 size_policy()->concurrent_precleaning_end(); | |
2368 } | |
2369 assert(_collectorState == FinalMarking, "Collector state should " | |
2370 "have changed"); | |
2371 break; | |
2372 case FinalMarking: | |
2373 { | |
2374 ReleaseForegroundGC x(this); | |
2375 | |
2376 VM_CMS_Final_Remark final_remark_op(this); | |
2377 VMThread::execute(&final_remark_op); | |
935 | 2378 } |
0 | 2379 assert(_foregroundGCShouldWait, "block post-condition"); |
2380 break; | |
2381 case Sweeping: | |
2382 if (UseAdaptiveSizePolicy) { | |
2383 size_policy()->concurrent_sweeping_begin(); | |
2384 } | |
2385 // final marking in checkpointRootsFinal has been completed | |
2386 sweep(true); | |
2387 assert(_collectorState == Resizing, "Collector state change " | |
2388 "to Resizing must be done under the free_list_lock"); | |
2389 _full_gcs_since_conc_gc = 0; | |
2390 | |
2391 // Stop the timers for adaptive size policy for the concurrent phases | |
2392 if (UseAdaptiveSizePolicy) { | |
2393 size_policy()->concurrent_sweeping_end(); | |
2394 size_policy()->concurrent_phases_end(gch->gc_cause(), | |
2395 gch->prev_gen(_cmsGen)->capacity(), | |
2396 _cmsGen->free()); | |
2397 } | |
2398 | |
2399 case Resizing: { | |
2400 // Sweeping has been completed... | |
2401 // At this point the background collection has completed. | |
2402 // Don't move the call to compute_new_size() down | |
2403 // into code that might be executed if the background | |
2404 // collection was preempted. | |
2405 { | |
2406 ReleaseForegroundGC x(this); // unblock FG collection | |
2407 MutexLockerEx y(Heap_lock, Mutex::_no_safepoint_check_flag); | |
2408 CMSTokenSync z(true); // not strictly needed. | |
2409 if (_collectorState == Resizing) { | |
2410 compute_new_size(); | |
10405 | 2411 save_heap_summary(); |
0 | 2412 _collectorState = Resetting; |
2413 } else { | |
2414 assert(_collectorState == Idling, "The state should only change" | |
2415 " because the foreground collector has finished the collection"); | |
2416 } | |
2417 } | |
2418 break; | |
2419 } | |
2420 case Resetting: | |
2421 // CMS heap resizing has been completed | |
2422 reset(true); | |
2423 assert(_collectorState == Idling, "Collector state should " | |
2424 "have changed"); | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2425 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2426 MetaspaceGC::set_should_concurrent_collect(false); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2427 |
0 | 2428 stats().record_cms_end(); |
2429 // Don't move the concurrent_phases_end() and compute_new_size() | |
2430 // calls to here because a preempted background collection | |
2431 // has it's state set to "Resetting". | |
2432 break; | |
2433 case Idling: | |
2434 default: | |
2435 ShouldNotReachHere(); | |
2436 break; | |
2437 } | |
2438 if (TraceCMSState) { | |
2439 gclog_or_tty->print_cr(" Thread " INTPTR_FORMAT " done - next CMS state %d", | |
2440 Thread::current(), _collectorState); | |
2441 } | |
2442 assert(_foregroundGCShouldWait, "block post-condition"); | |
2443 } | |
2444 | |
2445 // Should this be in gc_epilogue? | |
2446 collector_policy()->counters()->update_counters(); | |
2447 | |
2448 { | |
2449 // Clear _foregroundGCShouldWait and, in the event that the | |
2450 // foreground collector is waiting, notify it, before | |
2451 // returning. | |
2452 MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag); | |
2453 _foregroundGCShouldWait = false; | |
2454 if (_foregroundGCIsActive) { | |
2455 CGC_lock->notify(); | |
2456 } | |
2457 assert(!ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
2458 "Possible deadlock"); | |
2459 } | |
2460 if (TraceCMSState) { | |
2461 gclog_or_tty->print_cr("CMS Thread " INTPTR_FORMAT | |
2462 " exiting collection CMS state %d", | |
2463 Thread::current(), _collectorState); | |
2464 } | |
2465 if (PrintGC && Verbose) { | |
2466 _cmsGen->print_heap_change(prev_used); | |
2467 } | |
2468 } | |
2469 | |
10405 | 2470 void CMSCollector::register_foreground_gc_start(GCCause::Cause cause) { |
2471 if (!_cms_start_registered) { | |
2472 register_gc_start(cause); | |
2473 } | |
2474 } | |
2475 | |
2476 void CMSCollector::register_gc_start(GCCause::Cause cause) { | |
2477 _cms_start_registered = true; | |
13400
86e6d691f2e1
8028128: Add a type safe alternative for working with counter based data
mgronlun
parents:
13064
diff
changeset
|
2478 _gc_timer_cm->register_gc_start(); |
10405 | 2479 _gc_tracer_cm->report_gc_start(cause, _gc_timer_cm->gc_start()); |
2480 } | |
2481 | |
2482 void CMSCollector::register_gc_end() { | |
2483 if (_cms_start_registered) { | |
2484 report_heap_summary(GCWhen::AfterGC); | |
2485 | |
13400
86e6d691f2e1
8028128: Add a type safe alternative for working with counter based data
mgronlun
parents:
13064
diff
changeset
|
2486 _gc_timer_cm->register_gc_end(); |
10405 | 2487 _gc_tracer_cm->report_gc_end(_gc_timer_cm->gc_end(), _gc_timer_cm->time_partitions()); |
2488 _cms_start_registered = false; | |
2489 } | |
2490 } | |
2491 | |
2492 void CMSCollector::save_heap_summary() { | |
2493 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
2494 _last_heap_summary = gch->create_heap_summary(); | |
2495 _last_metaspace_summary = gch->create_metaspace_summary(); | |
2496 } | |
2497 | |
2498 void CMSCollector::report_heap_summary(GCWhen::Type when) { | |
2499 _gc_tracer_cm->report_gc_heap_summary(when, _last_heap_summary, _last_metaspace_summary); | |
2500 } | |
2501 | |
2502 void CMSCollector::collect_in_foreground(bool clear_all_soft_refs, GCCause::Cause cause) { | |
0 | 2503 assert(_foregroundGCIsActive && !_foregroundGCShouldWait, |
2504 "Foreground collector should be waiting, not executing"); | |
2505 assert(Thread::current()->is_VM_thread(), "A foreground collection" | |
2506 "may only be done by the VM Thread with the world stopped"); | |
2507 assert(ConcurrentMarkSweepThread::vm_thread_has_cms_token(), | |
2508 "VM thread should have CMS token"); | |
2509 | |
10405 | 2510 NOT_PRODUCT(GCTraceTime t("CMS:MS (foreground) ", PrintGCDetails && Verbose, |
2511 true, NULL);) | |
0 | 2512 if (UseAdaptiveSizePolicy) { |
2513 size_policy()->ms_collection_begin(); | |
2514 } | |
2515 COMPILER2_PRESENT(DerivedPointerTableDeactivate dpt_deact); | |
2516 | |
2517 HandleMark hm; // Discard invalid handles created during verification | |
2518 | |
2519 if (VerifyBeforeGC && | |
2520 GenCollectedHeap::heap()->total_collections() >= VerifyGCStartAt) { | |
6865
4202510ee0fe
8000831: Heap verification output incorrect/incomplete
johnc
parents:
6787
diff
changeset
|
2521 Universe::verify(); |
0 | 2522 } |
2523 | |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
2524 // Snapshot the soft reference policy to be used in this collection cycle. |
457
27a80744a83b
6778647: snap(), snap_policy() should be renamed setup(), setup_policy()
ysr
parents:
453
diff
changeset
|
2525 ref_processor()->setup_policy(clear_all_soft_refs); |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
2526 |
13064
592d8b01fedd
8024483: assertion failure: (!mirror_alive || loader_alive) failed:
jmasa
parents:
13063
diff
changeset
|
2527 // Decide if class unloading should be done |
592d8b01fedd
8024483: assertion failure: (!mirror_alive || loader_alive) failed:
jmasa
parents:
13063
diff
changeset
|
2528 update_should_unload_classes(); |
592d8b01fedd
8024483: assertion failure: (!mirror_alive || loader_alive) failed:
jmasa
parents:
13063
diff
changeset
|
2529 |
0 | 2530 bool init_mark_was_synchronous = false; // until proven otherwise |
2531 while (_collectorState != Idling) { | |
2532 if (TraceCMSState) { | |
2533 gclog_or_tty->print_cr("Thread " INTPTR_FORMAT " in CMS state %d", | |
2534 Thread::current(), _collectorState); | |
2535 } | |
2536 switch (_collectorState) { | |
2537 case InitialMarking: | |
10405 | 2538 register_foreground_gc_start(cause); |
0 | 2539 init_mark_was_synchronous = true; // fact to be exploited in re-mark |
2540 checkpointRootsInitial(false); | |
2541 assert(_collectorState == Marking, "Collector state should have changed" | |
2542 " within checkpointRootsInitial()"); | |
2543 break; | |
2544 case Marking: | |
2545 // initial marking in checkpointRootsInitialWork has been completed | |
2546 if (VerifyDuringGC && | |
2547 GenCollectedHeap::heap()->total_collections() >= VerifyGCStartAt) { | |
10186
b06ac540229e
8013132: Add a flag to turn off the output of the verbose verification code
stefank
parents:
10180
diff
changeset
|
2548 Universe::verify("Verify before initial mark: "); |
0 | 2549 } |
2550 { | |
2551 bool res = markFromRoots(false); | |
2552 assert(res && _collectorState == FinalMarking, "Collector state should " | |
2553 "have changed"); | |
2554 break; | |
2555 } | |
2556 case FinalMarking: | |
2557 if (VerifyDuringGC && | |
2558 GenCollectedHeap::heap()->total_collections() >= VerifyGCStartAt) { | |
10186
b06ac540229e
8013132: Add a flag to turn off the output of the verbose verification code
stefank
parents:
10180
diff
changeset
|
2559 Universe::verify("Verify before re-mark: "); |
0 | 2560 } |
2561 checkpointRootsFinal(false, clear_all_soft_refs, | |
2562 init_mark_was_synchronous); | |
2563 assert(_collectorState == Sweeping, "Collector state should not " | |
2564 "have changed within checkpointRootsFinal()"); | |
2565 break; | |
2566 case Sweeping: | |
2567 // final marking in checkpointRootsFinal has been completed | |
2568 if (VerifyDuringGC && | |
2569 GenCollectedHeap::heap()->total_collections() >= VerifyGCStartAt) { | |
10186
b06ac540229e
8013132: Add a flag to turn off the output of the verbose verification code
stefank
parents:
10180
diff
changeset
|
2570 Universe::verify("Verify before sweep: "); |
0 | 2571 } |
2572 sweep(false); | |
2573 assert(_collectorState == Resizing, "Incorrect state"); | |
2574 break; | |
2575 case Resizing: { | |
2576 // Sweeping has been completed; the actual resize in this case | |
2577 // is done separately; nothing to be done in this state. | |
2578 _collectorState = Resetting; | |
2579 break; | |
2580 } | |
2581 case Resetting: | |
2582 // The heap has been resized. | |
2583 if (VerifyDuringGC && | |
2584 GenCollectedHeap::heap()->total_collections() >= VerifyGCStartAt) { | |
10186
b06ac540229e
8013132: Add a flag to turn off the output of the verbose verification code
stefank
parents:
10180
diff
changeset
|
2585 Universe::verify("Verify before reset: "); |
0 | 2586 } |
10405 | 2587 save_heap_summary(); |
0 | 2588 reset(false); |
2589 assert(_collectorState == Idling, "Collector state should " | |
2590 "have changed"); | |
2591 break; | |
2592 case Precleaning: | |
2593 case AbortablePreclean: | |
2594 // Elide the preclean phase | |
2595 _collectorState = FinalMarking; | |
2596 break; | |
2597 default: | |
2598 ShouldNotReachHere(); | |
2599 } | |
2600 if (TraceCMSState) { | |
2601 gclog_or_tty->print_cr(" Thread " INTPTR_FORMAT " done - next CMS state %d", | |
2602 Thread::current(), _collectorState); | |
2603 } | |
2604 } | |
2605 | |
2606 if (UseAdaptiveSizePolicy) { | |
2607 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
2608 size_policy()->ms_collection_end(gch->gc_cause()); | |
2609 } | |
2610 | |
2611 if (VerifyAfterGC && | |
2612 GenCollectedHeap::heap()->total_collections() >= VerifyGCStartAt) { | |
6865
4202510ee0fe
8000831: Heap verification output incorrect/incomplete
johnc
parents:
6787
diff
changeset
|
2613 Universe::verify(); |
0 | 2614 } |
2615 if (TraceCMSState) { | |
2616 gclog_or_tty->print_cr("CMS Thread " INTPTR_FORMAT | |
2617 " exiting collection CMS state %d", | |
2618 Thread::current(), _collectorState); | |
2619 } | |
2620 } | |
2621 | |
2622 bool CMSCollector::waitForForegroundGC() { | |
2623 bool res = false; | |
2624 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
2625 "CMS thread should have CMS token"); | |
2626 // Block the foreground collector until the | |
2627 // background collectors decides whether to | |
2628 // yield. | |
2629 MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag); | |
2630 _foregroundGCShouldWait = true; | |
2631 if (_foregroundGCIsActive) { | |
2632 // The background collector yields to the | |
2633 // foreground collector and returns a value | |
2634 // indicating that it has yielded. The foreground | |
2635 // collector can proceed. | |
2636 res = true; | |
2637 _foregroundGCShouldWait = false; | |
2638 ConcurrentMarkSweepThread::clear_CMS_flag( | |
2639 ConcurrentMarkSweepThread::CMS_cms_has_token); | |
2640 ConcurrentMarkSweepThread::set_CMS_flag( | |
2641 ConcurrentMarkSweepThread::CMS_cms_wants_token); | |
2642 // Get a possibly blocked foreground thread going | |
2643 CGC_lock->notify(); | |
2644 if (TraceCMSState) { | |
2645 gclog_or_tty->print_cr("CMS Thread " INTPTR_FORMAT " waiting at CMS state %d", | |
2646 Thread::current(), _collectorState); | |
2647 } | |
2648 while (_foregroundGCIsActive) { | |
2649 CGC_lock->wait(Mutex::_no_safepoint_check_flag); | |
2650 } | |
2651 ConcurrentMarkSweepThread::set_CMS_flag( | |
2652 ConcurrentMarkSweepThread::CMS_cms_has_token); | |
2653 ConcurrentMarkSweepThread::clear_CMS_flag( | |
2654 ConcurrentMarkSweepThread::CMS_cms_wants_token); | |
2655 } | |
2656 if (TraceCMSState) { | |
2657 gclog_or_tty->print_cr("CMS Thread " INTPTR_FORMAT " continuing at CMS state %d", | |
2658 Thread::current(), _collectorState); | |
2659 } | |
2660 return res; | |
2661 } | |
2662 | |
2663 // Because of the need to lock the free lists and other structures in | |
2664 // the collector, common to all the generations that the collector is | |
2665 // collecting, we need the gc_prologues of individual CMS generations | |
2666 // delegate to their collector. It may have been simpler had the | |
2667 // current infrastructure allowed one to call a prologue on a | |
2668 // collector. In the absence of that we have the generation's | |
2669 // prologue delegate to the collector, which delegates back | |
2670 // some "local" work to a worker method in the individual generations | |
2671 // that it's responsible for collecting, while itself doing any | |
2672 // work common to all generations it's responsible for. A similar | |
2673 // comment applies to the gc_epilogue()'s. | |
14309 | 2674 // The role of the variable _between_prologue_and_epilogue is to |
0 | 2675 // enforce the invocation protocol. |
2676 void CMSCollector::gc_prologue(bool full) { | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2677 // Call gc_prologue_work() for the CMSGen |
0 | 2678 // we are responsible for. |
2679 | |
2680 // The following locking discipline assumes that we are only called | |
2681 // when the world is stopped. | |
2682 assert(SafepointSynchronize::is_at_safepoint(), "world is stopped assumption"); | |
2683 | |
2684 // The CMSCollector prologue must call the gc_prologues for the | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2685 // "generations" that it's responsible |
0 | 2686 // for. |
2687 | |
2688 assert( Thread::current()->is_VM_thread() | |
2689 || ( CMSScavengeBeforeRemark | |
2690 && Thread::current()->is_ConcurrentGC_thread()), | |
2691 "Incorrect thread type for prologue execution"); | |
2692 | |
2693 if (_between_prologue_and_epilogue) { | |
2694 // We have already been invoked; this is a gc_prologue delegation | |
2695 // from yet another CMS generation that we are responsible for, just | |
2696 // ignore it since all relevant work has already been done. | |
2697 return; | |
2698 } | |
2699 | |
2700 // set a bit saying prologue has been called; cleared in epilogue | |
2701 _between_prologue_and_epilogue = true; | |
2702 // Claim locks for common data structures, then call gc_prologue_work() | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2703 // for each CMSGen. |
0 | 2704 |
2705 getFreelistLocks(); // gets free list locks on constituent spaces | |
2706 bitMapLock()->lock_without_safepoint_check(); | |
2707 | |
2708 // Should call gc_prologue_work() for all cms gens we are responsible for | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2709 bool duringMarking = _collectorState >= Marking |
0 | 2710 && _collectorState < Sweeping; |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2711 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2712 // The young collections clear the modified oops state, which tells if |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2713 // there are any modified oops in the class. The remark phase also needs |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2714 // that information. Tell the young collection to save the union of all |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2715 // modified klasses. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2716 if (duringMarking) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2717 _ct->klass_rem_set()->set_accumulate_modified_oops(true); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2718 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2719 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2720 bool registerClosure = duringMarking; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2721 |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
2722 ModUnionClosure* muc = CollectedHeap::use_parallel_gc_threads() ? |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
2723 &_modUnionClosurePar |
0 | 2724 : &_modUnionClosure; |
2725 _cmsGen->gc_prologue_work(full, registerClosure, muc); | |
2726 | |
2727 if (!full) { | |
2728 stats().record_gc0_begin(); | |
2729 } | |
2730 } | |
2731 | |
2732 void ConcurrentMarkSweepGeneration::gc_prologue(bool full) { | |
9072
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
2733 |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
2734 _capacity_at_prologue = capacity(); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
2735 _used_at_prologue = used(); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
2736 |
0 | 2737 // Delegate to CMScollector which knows how to coordinate between |
2738 // this and any other CMS generations that it is responsible for | |
2739 // collecting. | |
2740 collector()->gc_prologue(full); | |
2741 } | |
2742 | |
2743 // This is a "private" interface for use by this generation's CMSCollector. | |
2744 // Not to be called directly by any other entity (for instance, | |
2745 // GenCollectedHeap, which calls the "public" gc_prologue method above). | |
2746 void ConcurrentMarkSweepGeneration::gc_prologue_work(bool full, | |
2747 bool registerClosure, ModUnionClosure* modUnionClosure) { | |
2748 assert(!incremental_collection_failed(), "Shouldn't be set yet"); | |
2749 assert(cmsSpace()->preconsumptionDirtyCardClosure() == NULL, | |
2750 "Should be NULL"); | |
2751 if (registerClosure) { | |
2752 cmsSpace()->setPreconsumptionDirtyCardClosure(modUnionClosure); | |
2753 } | |
2754 cmsSpace()->gc_prologue(); | |
2755 // Clear stat counters | |
2756 NOT_PRODUCT( | |
2757 assert(_numObjectsPromoted == 0, "check"); | |
2758 assert(_numWordsPromoted == 0, "check"); | |
2759 if (Verbose && PrintGC) { | |
2760 gclog_or_tty->print("Allocated "SIZE_FORMAT" objects, " | |
2761 SIZE_FORMAT" bytes concurrently", | |
2762 _numObjectsAllocated, _numWordsAllocated*sizeof(HeapWord)); | |
2763 } | |
2764 _numObjectsAllocated = 0; | |
2765 _numWordsAllocated = 0; | |
2766 ) | |
2767 } | |
2768 | |
2769 void CMSCollector::gc_epilogue(bool full) { | |
2770 // The following locking discipline assumes that we are only called | |
2771 // when the world is stopped. | |
2772 assert(SafepointSynchronize::is_at_safepoint(), | |
2773 "world is stopped assumption"); | |
2774 | |
2775 // Currently the CMS epilogue (see CompactibleFreeListSpace) merely checks | |
2776 // if linear allocation blocks need to be appropriately marked to allow the | |
2777 // the blocks to be parsable. We also check here whether we need to nudge the | |
2778 // CMS collector thread to start a new cycle (if it's not already active). | |
2779 assert( Thread::current()->is_VM_thread() | |
2780 || ( CMSScavengeBeforeRemark | |
2781 && Thread::current()->is_ConcurrentGC_thread()), | |
2782 "Incorrect thread type for epilogue execution"); | |
2783 | |
2784 if (!_between_prologue_and_epilogue) { | |
2785 // We have already been invoked; this is a gc_epilogue delegation | |
2786 // from yet another CMS generation that we are responsible for, just | |
2787 // ignore it since all relevant work has already been done. | |
2788 return; | |
2789 } | |
2790 assert(haveFreelistLocks(), "must have freelist locks"); | |
2791 assert_lock_strong(bitMapLock()); | |
2792 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2793 _ct->klass_rem_set()->set_accumulate_modified_oops(false); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
2794 |
0 | 2795 _cmsGen->gc_epilogue_work(full); |
2796 | |
2797 if (_collectorState == AbortablePreclean || _collectorState == Precleaning) { | |
2798 // in case sampling was not already enabled, enable it | |
2799 _start_sampling = true; | |
2800 } | |
2801 // reset _eden_chunk_array so sampling starts afresh | |
2802 _eden_chunk_index = 0; | |
2803 | |
2804 size_t cms_used = _cmsGen->cmsSpace()->used(); | |
2805 | |
2806 // update performance counters - this uses a special version of | |
2807 // update_counters() that allows the utilization to be passed as a | |
2808 // parameter, avoiding multiple calls to used(). | |
2809 // | |
2810 _cmsGen->update_counters(cms_used); | |
2811 | |
2812 if (CMSIncrementalMode) { | |
2813 icms_update_allocation_limits(); | |
2814 } | |
2815 | |
2816 bitMapLock()->unlock(); | |
2817 releaseFreelistLocks(); | |
2818 | |
3799
48048b59a551
7061204: clean the chunk table synchronously in embedded builds
jcoomes
parents:
3746
diff
changeset
|
2819 if (!CleanChunkPoolAsync) { |
48048b59a551
7061204: clean the chunk table synchronously in embedded builds
jcoomes
parents:
3746
diff
changeset
|
2820 Chunk::clean_chunk_pool(); |
48048b59a551
7061204: clean the chunk table synchronously in embedded builds
jcoomes
parents:
3746
diff
changeset
|
2821 } |
48048b59a551
7061204: clean the chunk table synchronously in embedded builds
jcoomes
parents:
3746
diff
changeset
|
2822 |
10244
06ab37f08701
8013184: CMS: Call reset_after_compaction() only if a compaction has been done
jmasa
parents:
10243
diff
changeset
|
2823 set_did_compact(false); |
0 | 2824 _between_prologue_and_epilogue = false; // ready for next cycle |
2825 } | |
2826 | |
2827 void ConcurrentMarkSweepGeneration::gc_epilogue(bool full) { | |
2828 collector()->gc_epilogue(full); | |
2829 | |
2830 // Also reset promotion tracking in par gc thread states. | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
2831 if (CollectedHeap::use_parallel_gc_threads()) { |
0 | 2832 for (uint i = 0; i < ParallelGCThreads; i++) { |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2833 _par_gc_thread_states[i]->promo.stopTrackingPromotions(i); |
0 | 2834 } |
2835 } | |
2836 } | |
2837 | |
2838 void ConcurrentMarkSweepGeneration::gc_epilogue_work(bool full) { | |
2839 assert(!incremental_collection_failed(), "Should have been cleared"); | |
2840 cmsSpace()->setPreconsumptionDirtyCardClosure(NULL); | |
2841 cmsSpace()->gc_epilogue(); | |
2842 // Print stat counters | |
2843 NOT_PRODUCT( | |
2844 assert(_numObjectsAllocated == 0, "check"); | |
2845 assert(_numWordsAllocated == 0, "check"); | |
2846 if (Verbose && PrintGC) { | |
2847 gclog_or_tty->print("Promoted "SIZE_FORMAT" objects, " | |
2848 SIZE_FORMAT" bytes", | |
2849 _numObjectsPromoted, _numWordsPromoted*sizeof(HeapWord)); | |
2850 } | |
2851 _numObjectsPromoted = 0; | |
2852 _numWordsPromoted = 0; | |
2853 ) | |
2854 | |
2855 if (PrintGC && Verbose) { | |
2856 // Call down the chain in contiguous_available needs the freelistLock | |
2857 // so print this out before releasing the freeListLock. | |
2858 gclog_or_tty->print(" Contiguous available "SIZE_FORMAT" bytes ", | |
2859 contiguous_available()); | |
2860 } | |
2861 } | |
2862 | |
2863 #ifndef PRODUCT | |
2864 bool CMSCollector::have_cms_token() { | |
2865 Thread* thr = Thread::current(); | |
2866 if (thr->is_VM_thread()) { | |
2867 return ConcurrentMarkSweepThread::vm_thread_has_cms_token(); | |
2868 } else if (thr->is_ConcurrentGC_thread()) { | |
2869 return ConcurrentMarkSweepThread::cms_thread_has_cms_token(); | |
2870 } else if (thr->is_GC_task_thread()) { | |
2871 return ConcurrentMarkSweepThread::vm_thread_has_cms_token() && | |
2872 ParGCRareEvent_lock->owned_by_self(); | |
2873 } | |
2874 return false; | |
2875 } | |
2876 #endif | |
2877 | |
2878 // Check reachability of the given heap address in CMS generation, | |
2879 // treating all other generations as roots. | |
2880 bool CMSCollector::is_cms_reachable(HeapWord* addr) { | |
14309 | 2881 // We could "guarantee" below, rather than assert, but I'll |
0 | 2882 // leave these as "asserts" so that an adventurous debugger |
2883 // could try this in the product build provided some subset of | |
14309 | 2884 // the conditions were met, provided they were interested in the |
0 | 2885 // results and knew that the computation below wouldn't interfere |
2886 // with other concurrent computations mutating the structures | |
2887 // being read or written. | |
2888 assert(SafepointSynchronize::is_at_safepoint(), | |
2889 "Else mutations in object graph will make answer suspect"); | |
2890 assert(have_cms_token(), "Should hold cms token"); | |
2891 assert(haveFreelistLocks(), "must hold free list locks"); | |
2892 assert_lock_strong(bitMapLock()); | |
2893 | |
2894 // Clear the marking bit map array before starting, but, just | |
2895 // for kicks, first report if the given address is already marked | |
2896 gclog_or_tty->print_cr("Start: Address 0x%x is%s marked", addr, | |
2897 _markBitMap.isMarked(addr) ? "" : " not"); | |
2898 | |
2899 if (verify_after_remark()) { | |
2900 MutexLockerEx x(verification_mark_bm()->lock(), Mutex::_no_safepoint_check_flag); | |
2901 bool result = verification_mark_bm()->isMarked(addr); | |
2902 gclog_or_tty->print_cr("TransitiveMark: Address 0x%x %s marked", addr, | |
2903 result ? "IS" : "is NOT"); | |
2904 return result; | |
2905 } else { | |
2906 gclog_or_tty->print_cr("Could not compute result"); | |
2907 return false; | |
2908 } | |
2909 } | |
2910 | |
9076
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2911 |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2912 void |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2913 CMSCollector::print_on_error(outputStream* st) { |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2914 CMSCollector* collector = ConcurrentMarkSweepGeneration::_collector; |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2915 if (collector != NULL) { |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2916 CMSBitMap* bitmap = &collector->_markBitMap; |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2917 st->print_cr("Marking Bits: (CMSBitMap*) " PTR_FORMAT, bitmap); |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2918 bitmap->print_on_error(st, " Bits: "); |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2919 |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2920 st->cr(); |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2921 |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2922 CMSBitMap* mut_bitmap = &collector->_modUnionTable; |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2923 st->print_cr("Mod Union Table: (CMSBitMap*) " PTR_FORMAT, mut_bitmap); |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2924 mut_bitmap->print_on_error(st, " Bits: "); |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2925 } |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2926 } |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
2927 |
0 | 2928 //////////////////////////////////////////////////////// |
2929 // CMS Verification Support | |
2930 //////////////////////////////////////////////////////// | |
2931 // Following the remark phase, the following invariant | |
2932 // should hold -- each object in the CMS heap which is | |
2933 // marked in markBitMap() should be marked in the verification_mark_bm(). | |
2934 | |
2935 class VerifyMarkedClosure: public BitMapClosure { | |
2936 CMSBitMap* _marks; | |
2937 bool _failed; | |
2938 | |
2939 public: | |
2940 VerifyMarkedClosure(CMSBitMap* bm): _marks(bm), _failed(false) {} | |
2941 | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
2942 bool do_bit(size_t offset) { |
0 | 2943 HeapWord* addr = _marks->offsetToHeapWord(offset); |
2944 if (!_marks->isMarked(addr)) { | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2945 oop(addr)->print_on(gclog_or_tty); |
0 | 2946 gclog_or_tty->print_cr(" ("INTPTR_FORMAT" should have been marked)", addr); |
2947 _failed = true; | |
2948 } | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
2949 return true; |
0 | 2950 } |
2951 | |
2952 bool failed() { return _failed; } | |
2953 }; | |
2954 | |
10186
b06ac540229e
8013132: Add a flag to turn off the output of the verbose verification code
stefank
parents:
10180
diff
changeset
|
2955 bool CMSCollector::verify_after_remark(bool silent) { |
b06ac540229e
8013132: Add a flag to turn off the output of the verbose verification code
stefank
parents:
10180
diff
changeset
|
2956 if (!silent) gclog_or_tty->print(" [Verifying CMS Marking... "); |
0 | 2957 MutexLockerEx ml(verification_mark_bm()->lock(), Mutex::_no_safepoint_check_flag); |
2958 static bool init = false; | |
2959 | |
2960 assert(SafepointSynchronize::is_at_safepoint(), | |
2961 "Else mutations in object graph will make answer suspect"); | |
2962 assert(have_cms_token(), | |
2963 "Else there may be mutual interference in use of " | |
2964 " verification data structures"); | |
2965 assert(_collectorState > Marking && _collectorState <= Sweeping, | |
2966 "Else marking info checked here may be obsolete"); | |
2967 assert(haveFreelistLocks(), "must hold free list locks"); | |
2968 assert_lock_strong(bitMapLock()); | |
2969 | |
2970 | |
2971 // Allocate marking bit map if not already allocated | |
2972 if (!init) { // first time | |
2973 if (!verification_mark_bm()->allocate(_span)) { | |
2974 return false; | |
2975 } | |
2976 init = true; | |
2977 } | |
2978 | |
2979 assert(verification_mark_stack()->isEmpty(), "Should be empty"); | |
2980 | |
2981 // Turn off refs discovery -- so we will be tracing through refs. | |
2982 // This is as intended, because by this time | |
2983 // GC must already have cleared any refs that need to be cleared, | |
2984 // and traced those that need to be marked; moreover, | |
14309 | 2985 // the marking done here is not going to interfere in any |
0 | 2986 // way with the marking information used by GC. |
2987 NoRefDiscovery no_discovery(ref_processor()); | |
2988 | |
2989 COMPILER2_PRESENT(DerivedPointerTableDeactivate dpt_deact;) | |
2990 | |
2991 // Clear any marks from a previous round | |
2992 verification_mark_bm()->clear_all(); | |
2993 assert(verification_mark_stack()->isEmpty(), "markStack should be empty"); | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
2994 verify_work_stacks_empty(); |
0 | 2995 |
2996 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
2997 gch->ensure_parsability(false); // fill TLABs, but no need to retire them | |
2998 // Update the saved marks which may affect the root scans. | |
2999 gch->save_marks(); | |
3000 | |
3001 if (CMSRemarkVerifyVariant == 1) { | |
3002 // In this first variant of verification, we complete | |
14309 | 3003 // all marking, then check if the new marks-vector is |
0 | 3004 // a subset of the CMS marks-vector. |
3005 verify_after_remark_work_1(); | |
3006 } else if (CMSRemarkVerifyVariant == 2) { | |
3007 // In this second variant of verification, we flag an error | |
3008 // (i.e. an object reachable in the new marks-vector not reachable | |
3009 // in the CMS marks-vector) immediately, also indicating the | |
3010 // identify of an object (A) that references the unmarked object (B) -- | |
3011 // presumably, a mutation to A failed to be picked up by preclean/remark? | |
3012 verify_after_remark_work_2(); | |
3013 } else { | |
3014 warning("Unrecognized value %d for CMSRemarkVerifyVariant", | |
3015 CMSRemarkVerifyVariant); | |
3016 } | |
10186
b06ac540229e
8013132: Add a flag to turn off the output of the verbose verification code
stefank
parents:
10180
diff
changeset
|
3017 if (!silent) gclog_or_tty->print(" done] "); |
0 | 3018 return true; |
3019 } | |
3020 | |
3021 void CMSCollector::verify_after_remark_work_1() { | |
3022 ResourceMark rm; | |
3023 HandleMark hm; | |
3024 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
3025 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3026 // Get a clear set of claim bits for the strong roots processing to work with. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3027 ClassLoaderDataGraph::clear_claimed_marks(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3028 |
0 | 3029 // Mark from roots one level into CMS |
994
753cf9794df9
6885169: merge of 4957990 and 6863023 causes conflict on do_nmethods
jrose
parents:
993
diff
changeset
|
3030 MarkRefsIntoClosure notOlder(_span, verification_mark_bm()); |
0 | 3031 gch->rem_set()->prepare_for_younger_refs_iterate(false); // Not parallel. |
3032 | |
3033 gch->gen_process_strong_roots(_cmsGen->level(), | |
3034 true, // younger gens are roots | |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
3035 true, // activate StrongRootsScope |
0 | 3036 SharedHeap::ScanningOption(roots_scanning_options()), |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
3037 ¬Older, |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3038 NULL, |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3039 NULL); // SSS: Provide correct closure |
0 | 3040 |
3041 // Now mark from the roots | |
3042 MarkFromRootsClosure markFromRootsClosure(this, _span, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3043 verification_mark_bm(), verification_mark_stack(), |
0 | 3044 false /* don't yield */, true /* verifying */); |
3045 assert(_restart_addr == NULL, "Expected pre-condition"); | |
3046 verification_mark_bm()->iterate(&markFromRootsClosure); | |
3047 while (_restart_addr != NULL) { | |
3048 // Deal with stack overflow: by restarting at the indicated | |
3049 // address. | |
3050 HeapWord* ra = _restart_addr; | |
3051 markFromRootsClosure.reset(ra); | |
3052 _restart_addr = NULL; | |
3053 verification_mark_bm()->iterate(&markFromRootsClosure, ra, _span.end()); | |
3054 } | |
3055 assert(verification_mark_stack()->isEmpty(), "Should have been drained"); | |
3056 verify_work_stacks_empty(); | |
3057 | |
3058 // Marking completed -- now verify that each bit marked in | |
3059 // verification_mark_bm() is also marked in markBitMap(); flag all | |
3060 // errors by printing corresponding objects. | |
3061 VerifyMarkedClosure vcl(markBitMap()); | |
3062 verification_mark_bm()->iterate(&vcl); | |
3063 if (vcl.failed()) { | |
3064 gclog_or_tty->print("Verification failed"); | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
3065 Universe::heap()->print_on(gclog_or_tty); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
3066 fatal("CMS: failed marking verification after remark"); |
0 | 3067 } |
3068 } | |
3069 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3070 class VerifyKlassOopsKlassClosure : public KlassClosure { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3071 class VerifyKlassOopsClosure : public OopClosure { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3072 CMSBitMap* _bitmap; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3073 public: |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3074 VerifyKlassOopsClosure(CMSBitMap* bitmap) : _bitmap(bitmap) { } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3075 void do_oop(oop* p) { guarantee(*p == NULL || _bitmap->isMarked((HeapWord*) *p), "Should be marked"); } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3076 void do_oop(narrowOop* p) { ShouldNotReachHere(); } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3077 } _oop_closure; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3078 public: |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3079 VerifyKlassOopsKlassClosure(CMSBitMap* bitmap) : _oop_closure(bitmap) {} |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3080 void do_klass(Klass* k) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3081 k->oops_do(&_oop_closure); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3082 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3083 }; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3084 |
0 | 3085 void CMSCollector::verify_after_remark_work_2() { |
3086 ResourceMark rm; | |
3087 HandleMark hm; | |
3088 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
3089 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3090 // Get a clear set of claim bits for the strong roots processing to work with. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3091 ClassLoaderDataGraph::clear_claimed_marks(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3092 |
0 | 3093 // Mark from roots one level into CMS |
3094 MarkRefsIntoVerifyClosure notOlder(_span, verification_mark_bm(), | |
994
753cf9794df9
6885169: merge of 4957990 and 6863023 causes conflict on do_nmethods
jrose
parents:
993
diff
changeset
|
3095 markBitMap()); |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3096 CMKlassClosure klass_closure(¬Older); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3097 |
0 | 3098 gch->rem_set()->prepare_for_younger_refs_iterate(false); // Not parallel. |
3099 gch->gen_process_strong_roots(_cmsGen->level(), | |
3100 true, // younger gens are roots | |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
3101 true, // activate StrongRootsScope |
0 | 3102 SharedHeap::ScanningOption(roots_scanning_options()), |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
3103 ¬Older, |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3104 NULL, |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3105 &klass_closure); |
0 | 3106 |
3107 // Now mark from the roots | |
3108 MarkFromRootsVerifyClosure markFromRootsClosure(this, _span, | |
3109 verification_mark_bm(), markBitMap(), verification_mark_stack()); | |
3110 assert(_restart_addr == NULL, "Expected pre-condition"); | |
3111 verification_mark_bm()->iterate(&markFromRootsClosure); | |
3112 while (_restart_addr != NULL) { | |
3113 // Deal with stack overflow: by restarting at the indicated | |
3114 // address. | |
3115 HeapWord* ra = _restart_addr; | |
3116 markFromRootsClosure.reset(ra); | |
3117 _restart_addr = NULL; | |
3118 verification_mark_bm()->iterate(&markFromRootsClosure, ra, _span.end()); | |
3119 } | |
3120 assert(verification_mark_stack()->isEmpty(), "Should have been drained"); | |
3121 verify_work_stacks_empty(); | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3122 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3123 VerifyKlassOopsKlassClosure verify_klass_oops(verification_mark_bm()); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3124 ClassLoaderDataGraph::classes_do(&verify_klass_oops); |
0 | 3125 |
3126 // Marking completed -- now verify that each bit marked in | |
3127 // verification_mark_bm() is also marked in markBitMap(); flag all | |
3128 // errors by printing corresponding objects. | |
3129 VerifyMarkedClosure vcl(markBitMap()); | |
3130 verification_mark_bm()->iterate(&vcl); | |
3131 assert(!vcl.failed(), "Else verification above should not have succeeded"); | |
3132 } | |
3133 | |
3134 void ConcurrentMarkSweepGeneration::save_marks() { | |
3135 // delegate to CMS space | |
3136 cmsSpace()->save_marks(); | |
3137 for (uint i = 0; i < ParallelGCThreads; i++) { | |
3138 _par_gc_thread_states[i]->promo.startTrackingPromotions(); | |
3139 } | |
3140 } | |
3141 | |
3142 bool ConcurrentMarkSweepGeneration::no_allocs_since_save_marks() { | |
3143 return cmsSpace()->no_allocs_since_save_marks(); | |
3144 } | |
3145 | |
3146 #define CMS_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \ | |
3147 \ | |
3148 void ConcurrentMarkSweepGeneration:: \ | |
3149 oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl) { \ | |
3150 cl->set_generation(this); \ | |
3151 cmsSpace()->oop_since_save_marks_iterate##nv_suffix(cl); \ | |
3152 cl->reset_generation(); \ | |
3153 save_marks(); \ | |
3154 } | |
3155 | |
3156 ALL_SINCE_SAVE_MARKS_CLOSURES(CMS_SINCE_SAVE_MARKS_DEFN) | |
3157 | |
3158 void | |
3159 ConcurrentMarkSweepGeneration::younger_refs_iterate(OopsInGenClosure* cl) { | |
3160 cl->set_generation(this); | |
3161 younger_refs_in_space_iterate(_cmsSpace, cl); | |
3162 cl->reset_generation(); | |
3163 } | |
3164 | |
3165 void | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3166 ConcurrentMarkSweepGeneration::oop_iterate(MemRegion mr, ExtendedOopClosure* cl) { |
0 | 3167 if (freelistLock()->owned_by_self()) { |
3168 Generation::oop_iterate(mr, cl); | |
3169 } else { | |
3170 MutexLockerEx x(freelistLock(), Mutex::_no_safepoint_check_flag); | |
3171 Generation::oop_iterate(mr, cl); | |
3172 } | |
3173 } | |
3174 | |
3175 void | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3176 ConcurrentMarkSweepGeneration::oop_iterate(ExtendedOopClosure* cl) { |
0 | 3177 if (freelistLock()->owned_by_self()) { |
3178 Generation::oop_iterate(cl); | |
3179 } else { | |
3180 MutexLockerEx x(freelistLock(), Mutex::_no_safepoint_check_flag); | |
3181 Generation::oop_iterate(cl); | |
3182 } | |
3183 } | |
3184 | |
3185 void | |
3186 ConcurrentMarkSweepGeneration::object_iterate(ObjectClosure* cl) { | |
3187 if (freelistLock()->owned_by_self()) { | |
3188 Generation::object_iterate(cl); | |
3189 } else { | |
3190 MutexLockerEx x(freelistLock(), Mutex::_no_safepoint_check_flag); | |
3191 Generation::object_iterate(cl); | |
3192 } | |
3193 } | |
3194 | |
3195 void | |
517
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
457
diff
changeset
|
3196 ConcurrentMarkSweepGeneration::safe_object_iterate(ObjectClosure* cl) { |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
457
diff
changeset
|
3197 if (freelistLock()->owned_by_self()) { |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
457
diff
changeset
|
3198 Generation::safe_object_iterate(cl); |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
457
diff
changeset
|
3199 } else { |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
457
diff
changeset
|
3200 MutexLockerEx x(freelistLock(), Mutex::_no_safepoint_check_flag); |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
457
diff
changeset
|
3201 Generation::safe_object_iterate(cl); |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
457
diff
changeset
|
3202 } |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
457
diff
changeset
|
3203 } |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
457
diff
changeset
|
3204 |
e9be0e04635a
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
457
diff
changeset
|
3205 void |
0 | 3206 ConcurrentMarkSweepGeneration::post_compact() { |
3207 } | |
3208 | |
3209 void | |
3210 ConcurrentMarkSweepGeneration::prepare_for_verify() { | |
3211 // Fix the linear allocation blocks to look like free blocks. | |
3212 | |
3213 // Locks are normally acquired/released in gc_prologue/gc_epilogue, but those | |
3214 // are not called when the heap is verified during universe initialization and | |
3215 // at vm shutdown. | |
3216 if (freelistLock()->owned_by_self()) { | |
3217 cmsSpace()->prepare_for_verify(); | |
3218 } else { | |
3219 MutexLockerEx fll(freelistLock(), Mutex::_no_safepoint_check_flag); | |
3220 cmsSpace()->prepare_for_verify(); | |
3221 } | |
3222 } | |
3223 | |
3224 void | |
6008 | 3225 ConcurrentMarkSweepGeneration::verify() { |
0 | 3226 // Locks are normally acquired/released in gc_prologue/gc_epilogue, but those |
3227 // are not called when the heap is verified during universe initialization and | |
3228 // at vm shutdown. | |
3229 if (freelistLock()->owned_by_self()) { | |
6008 | 3230 cmsSpace()->verify(); |
0 | 3231 } else { |
3232 MutexLockerEx fll(freelistLock(), Mutex::_no_safepoint_check_flag); | |
6008 | 3233 cmsSpace()->verify(); |
3234 } | |
3235 } | |
3236 | |
3237 void CMSCollector::verify() { | |
3238 _cmsGen->verify(); | |
0 | 3239 } |
3240 | |
3241 #ifndef PRODUCT | |
3242 bool CMSCollector::overflow_list_is_empty() const { | |
3243 assert(_num_par_pushes >= 0, "Inconsistency"); | |
3244 if (_overflow_list == NULL) { | |
3245 assert(_num_par_pushes == 0, "Inconsistency"); | |
3246 } | |
3247 return _overflow_list == NULL; | |
3248 } | |
3249 | |
3250 // The methods verify_work_stacks_empty() and verify_overflow_empty() | |
3251 // merely consolidate assertion checks that appear to occur together frequently. | |
3252 void CMSCollector::verify_work_stacks_empty() const { | |
3253 assert(_markStack.isEmpty(), "Marking stack should be empty"); | |
3254 assert(overflow_list_is_empty(), "Overflow list should be empty"); | |
3255 } | |
3256 | |
3257 void CMSCollector::verify_overflow_empty() const { | |
3258 assert(overflow_list_is_empty(), "Overflow list should be empty"); | |
3259 assert(no_preserved_marks(), "No preserved marks"); | |
3260 } | |
3261 #endif // PRODUCT | |
3262 | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3263 // Decide if we want to enable class unloading as part of the |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3264 // ensuing concurrent GC cycle. We will collect and |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3265 // unload classes if it's the case that: |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3266 // (1) an explicit gc request has been made and the flag |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3267 // ExplicitGCInvokesConcurrentAndUnloadsClasses is set, OR |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3268 // (2) (a) class unloading is enabled at the command line, and |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3269 // (b) old gen is getting really full |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3270 // NOTE: Provided there is no change in the state of the heap between |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3271 // calls to this method, it should have idempotent results. Moreover, |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3272 // its results should be monotonically increasing (i.e. going from 0 to 1, |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3273 // but not 1 to 0) between successive calls between which the heap was |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3274 // not collected. For the implementation below, it must thus rely on |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3275 // the property that concurrent_cycles_since_last_unload() |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3276 // will not decrease unless a collection cycle happened and that |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3277 // _cmsGen->is_too_full() are |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3278 // themselves also monotonic in that sense. See check_monotonicity() |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3279 // below. |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3280 void CMSCollector::update_should_unload_classes() { |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3281 _should_unload_classes = false; |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3282 // Condition 1 above |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3283 if (_full_gc_requested && ExplicitGCInvokesConcurrentAndUnloadsClasses) { |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3284 _should_unload_classes = true; |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3285 } else if (CMSClassUnloadingEnabled) { // Condition 2.a above |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3286 // Disjuncts 2.b.(i,ii,iii) above |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3287 _should_unload_classes = (concurrent_cycles_since_last_unload() >= |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3288 CMSClassUnloadingMaxInterval) |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3289 || _cmsGen->is_too_full(); |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3290 } |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3291 } |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3292 |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3293 bool ConcurrentMarkSweepGeneration::is_too_full() const { |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3294 bool res = should_concurrent_collect(); |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3295 res = res && (occupancy() > (double)CMSIsTooFullPercentage/100.0); |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3296 return res; |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3297 } |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3298 |
0 | 3299 void CMSCollector::setup_cms_unloading_and_verification_state() { |
3293
1f4413413144
7039089: G1: changeset for 7037276 broke heap verification, and related cleanups
ysr
parents:
2379
diff
changeset
|
3300 const bool should_verify = VerifyBeforeGC || VerifyAfterGC || VerifyDuringGC |
0 | 3301 || VerifyBeforeExit; |
14308
870aedf4ba4f
8032379: Remove the is_scavenging flag to process_strong_roots
mgerdin
parents:
13400
diff
changeset
|
3302 const int rso = SharedHeap::SO_Strings | SharedHeap::SO_AllCodeCache; |
0 | 3303 |
13063
40b8c6bad703
8024954: CMS: CMSClassUnloadingMaxInterval is not implemented correctly. This change is also part of the fix for 8024483.
jmasa
parents:
12316
diff
changeset
|
3304 // We set the proper root for this CMS cycle here. |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3305 if (should_unload_classes()) { // Should unload classes this cycle |
13063
40b8c6bad703
8024954: CMS: CMSClassUnloadingMaxInterval is not implemented correctly. This change is also part of the fix for 8024483.
jmasa
parents:
12316
diff
changeset
|
3306 remove_root_scanning_option(SharedHeap::SO_AllClasses); |
40b8c6bad703
8024954: CMS: CMSClassUnloadingMaxInterval is not implemented correctly. This change is also part of the fix for 8024483.
jmasa
parents:
12316
diff
changeset
|
3307 add_root_scanning_option(SharedHeap::SO_SystemClasses); |
0 | 3308 remove_root_scanning_option(rso); // Shrink the root set appropriately |
3309 set_verifying(should_verify); // Set verification state for this cycle | |
3310 return; // Nothing else needs to be done at this time | |
3311 } | |
3312 | |
3313 // Not unloading classes this cycle | |
14358 | 3314 assert(!should_unload_classes(), "Inconsistency!"); |
13063
40b8c6bad703
8024954: CMS: CMSClassUnloadingMaxInterval is not implemented correctly. This change is also part of the fix for 8024483.
jmasa
parents:
12316
diff
changeset
|
3315 remove_root_scanning_option(SharedHeap::SO_SystemClasses); |
40b8c6bad703
8024954: CMS: CMSClassUnloadingMaxInterval is not implemented correctly. This change is also part of the fix for 8024483.
jmasa
parents:
12316
diff
changeset
|
3316 add_root_scanning_option(SharedHeap::SO_AllClasses); |
40b8c6bad703
8024954: CMS: CMSClassUnloadingMaxInterval is not implemented correctly. This change is also part of the fix for 8024483.
jmasa
parents:
12316
diff
changeset
|
3317 |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
3318 if ((!verifying() || unloaded_classes_last_cycle()) && should_verify) { |
0 | 3319 // Include symbols, strings and code cache elements to prevent their resurrection. |
3320 add_root_scanning_option(rso); | |
3321 set_verifying(true); | |
3322 } else if (verifying() && !should_verify) { | |
3323 // We were verifying, but some verification flags got disabled. | |
3324 set_verifying(false); | |
3325 // Exclude symbols, strings and code cache elements from root scanning to | |
3326 // reduce IM and RM pauses. | |
3327 remove_root_scanning_option(rso); | |
3328 } | |
3329 } | |
3330 | |
3331 | |
3332 #ifndef PRODUCT | |
3333 HeapWord* CMSCollector::block_start(const void* p) const { | |
3334 const HeapWord* addr = (HeapWord*)p; | |
3335 if (_span.contains(p)) { | |
3336 if (_cmsGen->cmsSpace()->is_in_reserved(addr)) { | |
3337 return _cmsGen->cmsSpace()->block_start(p); | |
3338 } | |
3339 } | |
3340 return NULL; | |
3341 } | |
3342 #endif | |
3343 | |
3344 HeapWord* | |
3345 ConcurrentMarkSweepGeneration::expand_and_allocate(size_t word_size, | |
3346 bool tlab, | |
3347 bool parallel) { | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3348 CMSSynchronousYieldRequest yr; |
0 | 3349 assert(!tlab, "Can't deal with TLAB allocation"); |
3350 MutexLockerEx x(freelistLock(), Mutex::_no_safepoint_check_flag); | |
3351 expand(word_size*HeapWordSize, MinHeapDeltaBytes, | |
3352 CMSExpansionCause::_satisfy_allocation); | |
3353 if (GCExpandToAllocateDelayMillis > 0) { | |
3354 os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false); | |
3355 } | |
9
173195ff483a
6642634: Test nsk/regression/b6186200 crashed with SIGSEGV
ysr
parents:
7
diff
changeset
|
3356 return have_lock_and_allocate(word_size, tlab); |
0 | 3357 } |
3358 | |
3359 // YSR: All of this generation expansion/shrinking stuff is an exact copy of | |
3360 // OneContigSpaceCardGeneration, which makes me wonder if we should move this | |
3361 // to CardGeneration and share it... | |
271
818a18cd69a8
6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents:
196
diff
changeset
|
3362 bool ConcurrentMarkSweepGeneration::expand(size_t bytes, size_t expand_bytes) { |
818a18cd69a8
6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents:
196
diff
changeset
|
3363 return CardGeneration::expand(bytes, expand_bytes); |
818a18cd69a8
6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents:
196
diff
changeset
|
3364 } |
818a18cd69a8
6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents:
196
diff
changeset
|
3365 |
0 | 3366 void ConcurrentMarkSweepGeneration::expand(size_t bytes, size_t expand_bytes, |
3367 CMSExpansionCause::Cause cause) | |
3368 { | |
271
818a18cd69a8
6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents:
196
diff
changeset
|
3369 |
818a18cd69a8
6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents:
196
diff
changeset
|
3370 bool success = expand(bytes, expand_bytes); |
818a18cd69a8
6730514: assertion failure in mangling code when expanding by 0 bytes
jmasa
parents:
196
diff
changeset
|
3371 |
0 | 3372 // remember why we expanded; this information is used |
3373 // by shouldConcurrentCollect() when making decisions on whether to start | |
3374 // a new CMS cycle. | |
3375 if (success) { | |
3376 set_expansion_cause(cause); | |
3377 if (PrintGCDetails && Verbose) { | |
3378 gclog_or_tty->print_cr("Expanded CMS gen for %s", | |
3379 CMSExpansionCause::to_string(cause)); | |
3380 } | |
3381 } | |
3382 } | |
3383 | |
3384 HeapWord* ConcurrentMarkSweepGeneration::expand_and_par_lab_allocate(CMSParGCThreadState* ps, size_t word_sz) { | |
3385 HeapWord* res = NULL; | |
3386 MutexLocker x(ParGCRareEvent_lock); | |
3387 while (true) { | |
3388 // Expansion by some other thread might make alloc OK now: | |
3389 res = ps->lab.alloc(word_sz); | |
3390 if (res != NULL) return res; | |
3391 // If there's not enough expansion space available, give up. | |
3392 if (_virtual_space.uncommitted_size() < (word_sz * HeapWordSize)) { | |
3393 return NULL; | |
3394 } | |
3395 // Otherwise, we try expansion. | |
3396 expand(word_sz*HeapWordSize, MinHeapDeltaBytes, | |
3397 CMSExpansionCause::_allocate_par_lab); | |
3398 // Now go around the loop and try alloc again; | |
3399 // A competing par_promote might beat us to the expansion space, | |
14309 | 3400 // so we may go around the loop again if promotion fails again. |
0 | 3401 if (GCExpandToAllocateDelayMillis > 0) { |
3402 os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false); | |
3403 } | |
3404 } | |
3405 } | |
3406 | |
3407 | |
3408 bool ConcurrentMarkSweepGeneration::expand_and_ensure_spooling_space( | |
3409 PromotionInfo* promo) { | |
3410 MutexLocker x(ParGCRareEvent_lock); | |
3411 size_t refill_size_bytes = promo->refillSize() * HeapWordSize; | |
3412 while (true) { | |
3413 // Expansion by some other thread might make alloc OK now: | |
3414 if (promo->ensure_spooling_space()) { | |
3415 assert(promo->has_spooling_space(), | |
3416 "Post-condition of successful ensure_spooling_space()"); | |
3417 return true; | |
3418 } | |
3419 // If there's not enough expansion space available, give up. | |
3420 if (_virtual_space.uncommitted_size() < refill_size_bytes) { | |
3421 return false; | |
3422 } | |
3423 // Otherwise, we try expansion. | |
3424 expand(refill_size_bytes, MinHeapDeltaBytes, | |
3425 CMSExpansionCause::_allocate_par_spooling_space); | |
3426 // Now go around the loop and try alloc again; | |
3427 // A competing allocation might beat us to the expansion space, | |
3428 // so we may go around the loop again if allocation fails again. | |
3429 if (GCExpandToAllocateDelayMillis > 0) { | |
3430 os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false); | |
3431 } | |
3432 } | |
3433 } | |
3434 | |
3435 | |
9072
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3436 void ConcurrentMarkSweepGeneration::shrink_by(size_t bytes) { |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3437 assert_locked_or_safepoint(ExpandHeap_lock); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3438 // Shrink committed space |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3439 _virtual_space.shrink_by(bytes); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3440 // Shrink space; this also shrinks the space's BOT |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3441 _cmsSpace->set_end((HeapWord*) _virtual_space.high()); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3442 size_t new_word_size = heap_word_size(_cmsSpace->capacity()); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3443 // Shrink the shared block offset array |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3444 _bts->resize(new_word_size); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3445 MemRegion mr(_cmsSpace->bottom(), new_word_size); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3446 // Shrink the card table |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3447 Universe::heap()->barrier_set()->resize_covered_region(mr); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3448 |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3449 if (Verbose && PrintGC) { |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3450 size_t new_mem_size = _virtual_space.committed_size(); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3451 size_t old_mem_size = new_mem_size + bytes; |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3452 gclog_or_tty->print_cr("Shrinking %s from " SIZE_FORMAT "K to " SIZE_FORMAT "K", |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3453 name(), old_mem_size/K, new_mem_size/K); |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3454 } |
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3455 } |
0 | 3456 |
3457 void ConcurrentMarkSweepGeneration::shrink(size_t bytes) { | |
3458 assert_locked_or_safepoint(Heap_lock); | |
3459 size_t size = ReservedSpace::page_align_size_down(bytes); | |
12112
1bb10d3170fa
8022817: CMS should not shrink if compaction was not done
jmasa
parents:
12088
diff
changeset
|
3460 // Only shrink if a compaction was done so that all the free space |
1bb10d3170fa
8022817: CMS should not shrink if compaction was not done
jmasa
parents:
12088
diff
changeset
|
3461 // in the generation is in a contiguous block at the end. |
1bb10d3170fa
8022817: CMS should not shrink if compaction was not done
jmasa
parents:
12088
diff
changeset
|
3462 if (size > 0 && did_compact()) { |
0 | 3463 shrink_by(size); |
3464 } | |
3465 } | |
3466 | |
3467 bool ConcurrentMarkSweepGeneration::grow_by(size_t bytes) { | |
3468 assert_locked_or_safepoint(Heap_lock); | |
3469 bool result = _virtual_space.expand_by(bytes); | |
3470 if (result) { | |
3471 size_t new_word_size = | |
3472 heap_word_size(_virtual_space.committed_size()); | |
3473 MemRegion mr(_cmsSpace->bottom(), new_word_size); | |
3474 _bts->resize(new_word_size); // resize the block offset shared array | |
3475 Universe::heap()->barrier_set()->resize_covered_region(mr); | |
3476 // Hmmmm... why doesn't CFLS::set_end verify locking? | |
3477 // This is quite ugly; FIX ME XXX | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
3478 _cmsSpace->assert_locked(freelistLock()); |
0 | 3479 _cmsSpace->set_end((HeapWord*)_virtual_space.high()); |
3480 | |
3481 // update the space and generation capacity counters | |
3482 if (UsePerfData) { | |
3483 _space_counters->update_capacity(); | |
3484 _gen_counters->update_all(); | |
3485 } | |
3486 | |
3487 if (Verbose && PrintGC) { | |
3488 size_t new_mem_size = _virtual_space.committed_size(); | |
3489 size_t old_mem_size = new_mem_size - bytes; | |
7623
203f64878aab
7102489: RFE: cleanup jlong typedef on __APPLE__and _LLP64 systems.
hseigel
parents:
6885
diff
changeset
|
3490 gclog_or_tty->print_cr("Expanding %s from " SIZE_FORMAT "K by " SIZE_FORMAT "K to " SIZE_FORMAT "K", |
0 | 3491 name(), old_mem_size/K, bytes/K, new_mem_size/K); |
3492 } | |
3493 } | |
3494 return result; | |
3495 } | |
3496 | |
3497 bool ConcurrentMarkSweepGeneration::grow_to_reserved() { | |
3498 assert_locked_or_safepoint(Heap_lock); | |
3499 bool success = true; | |
3500 const size_t remaining_bytes = _virtual_space.uncommitted_size(); | |
3501 if (remaining_bytes > 0) { | |
3502 success = grow_by(remaining_bytes); | |
3503 DEBUG_ONLY(if (!success) warning("grow to reserved failed");) | |
3504 } | |
3505 return success; | |
3506 } | |
3507 | |
9072
8617e38bb4cb
8008508: CMS does not correctly reduce heap size after a Full GC
jmasa
parents:
8784
diff
changeset
|
3508 void ConcurrentMarkSweepGeneration::shrink_free_list_by(size_t bytes) { |
0 | 3509 assert_locked_or_safepoint(Heap_lock); |
3510 assert_lock_strong(freelistLock()); | |
10180
ebded0261dfc
8012111: Remove warning about CMS generation shrinking.
jmasa
parents:
9152
diff
changeset
|
3511 if (PrintGCDetails && Verbose) { |
ebded0261dfc
8012111: Remove warning about CMS generation shrinking.
jmasa
parents:
9152
diff
changeset
|
3512 warning("Shrinking of CMS not yet implemented"); |
ebded0261dfc
8012111: Remove warning about CMS generation shrinking.
jmasa
parents:
9152
diff
changeset
|
3513 } |
0 | 3514 return; |
3515 } | |
3516 | |
3517 | |
3518 // Simple ctor/dtor wrapper for accounting & timer chores around concurrent | |
3519 // phases. | |
3520 class CMSPhaseAccounting: public StackObj { | |
3521 public: | |
3522 CMSPhaseAccounting(CMSCollector *collector, | |
3523 const char *phase, | |
3524 bool print_cr = true); | |
3525 ~CMSPhaseAccounting(); | |
3526 | |
3527 private: | |
3528 CMSCollector *_collector; | |
3529 const char *_phase; | |
3530 elapsedTimer _wallclock; | |
3531 bool _print_cr; | |
3532 | |
3533 public: | |
3534 // Not MT-safe; so do not pass around these StackObj's | |
3535 // where they may be accessed by other threads. | |
3536 jlong wallclock_millis() { | |
3537 assert(_wallclock.is_active(), "Wall clock should not stop"); | |
3538 _wallclock.stop(); // to record time | |
3539 jlong ret = _wallclock.milliseconds(); | |
3540 _wallclock.start(); // restart | |
3541 return ret; | |
3542 } | |
3543 }; | |
3544 | |
3545 CMSPhaseAccounting::CMSPhaseAccounting(CMSCollector *collector, | |
3546 const char *phase, | |
3547 bool print_cr) : | |
3548 _collector(collector), _phase(phase), _print_cr(print_cr) { | |
3549 | |
3550 if (PrintCMSStatistics != 0) { | |
3551 _collector->resetYields(); | |
3552 } | |
8740
62609ffa2fc6
8008684: CMS: concurrent phase start markers should always be printed
tschatzl
parents:
8736
diff
changeset
|
3553 if (PrintGCDetails) { |
0 | 3554 gclog_or_tty->date_stamp(PrintGCDateStamps); |
8740
62609ffa2fc6
8008684: CMS: concurrent phase start markers should always be printed
tschatzl
parents:
8736
diff
changeset
|
3555 gclog_or_tty->stamp(PrintGCTimeStamps); |
62609ffa2fc6
8008684: CMS: concurrent phase start markers should always be printed
tschatzl
parents:
8736
diff
changeset
|
3556 gclog_or_tty->print_cr("[%s-concurrent-%s-start]", |
0 | 3557 _collector->cmsGen()->short_name(), _phase); |
3558 } | |
3559 _collector->resetTimer(); | |
3560 _wallclock.start(); | |
3561 _collector->startTimer(); | |
3562 } | |
3563 | |
3564 CMSPhaseAccounting::~CMSPhaseAccounting() { | |
3565 assert(_wallclock.is_active(), "Wall clock should not have stopped"); | |
3566 _collector->stopTimer(); | |
3567 _wallclock.stop(); | |
3568 if (PrintGCDetails) { | |
3569 gclog_or_tty->date_stamp(PrintGCDateStamps); | |
6752
9646b7ff4d14
7198130: G1: PrintReferenceGC output comes out of order
brutisso
parents:
6725
diff
changeset
|
3570 gclog_or_tty->stamp(PrintGCTimeStamps); |
0 | 3571 gclog_or_tty->print("[%s-concurrent-%s: %3.3f/%3.3f secs]", |
3572 _collector->cmsGen()->short_name(), | |
3573 _phase, _collector->timerValue(), _wallclock.seconds()); | |
3574 if (_print_cr) { | |
3575 gclog_or_tty->print_cr(""); | |
3576 } | |
3577 if (PrintCMSStatistics != 0) { | |
3578 gclog_or_tty->print_cr(" (CMS-concurrent-%s yielded %d times)", _phase, | |
3579 _collector->yields()); | |
3580 } | |
3581 } | |
3582 } | |
3583 | |
3584 // CMS work | |
3585 | |
11975 | 3586 // The common parts of CMSParInitialMarkTask and CMSParRemarkTask. |
3587 class CMSParMarkTask : public AbstractGangTask { | |
3588 protected: | |
3589 CMSCollector* _collector; | |
3590 int _n_workers; | |
3591 CMSParMarkTask(const char* name, CMSCollector* collector, int n_workers) : | |
3592 AbstractGangTask(name), | |
3593 _collector(collector), | |
3594 _n_workers(n_workers) {} | |
3595 // Work method in support of parallel rescan ... of young gen spaces | |
3596 void do_young_space_rescan(uint worker_id, OopsInGenClosure* cl, | |
3597 ContiguousSpace* space, | |
3598 HeapWord** chunk_array, size_t chunk_top); | |
3599 void work_on_young_gen_roots(uint worker_id, OopsInGenClosure* cl); | |
3600 }; | |
3601 | |
3602 // Parallel initial mark task | |
3603 class CMSParInitialMarkTask: public CMSParMarkTask { | |
3604 public: | |
3605 CMSParInitialMarkTask(CMSCollector* collector, int n_workers) : | |
3606 CMSParMarkTask("Scan roots and young gen for initial mark in parallel", | |
3607 collector, n_workers) {} | |
3608 void work(uint worker_id); | |
3609 }; | |
3610 | |
0 | 3611 // Checkpoint the roots into this generation from outside |
3612 // this generation. [Note this initial checkpoint need only | |
3613 // be approximate -- we'll do a catch up phase subsequently.] | |
3614 void CMSCollector::checkpointRootsInitial(bool asynch) { | |
3615 assert(_collectorState == InitialMarking, "Wrong collector state"); | |
3616 check_correct_thread_executing(); | |
3356
78542e2b5e35
7036199: Adding a notification to the implementation of GarbageCollectorMXBeans
fparain
parents:
3293
diff
changeset
|
3617 TraceCMSMemoryManagerStats tms(_collectorState,GenCollectedHeap::heap()->gc_cause()); |
2125
7246a374a9f2
6458402: 3 jvmti tests fail with CMS and +ExplicitGCInvokesConcurrent
kamg
parents:
1994
diff
changeset
|
3618 |
10405 | 3619 save_heap_summary(); |
3620 report_heap_summary(GCWhen::BeforeGC); | |
3621 | |
0 | 3622 ReferenceProcessor* rp = ref_processor(); |
3623 SpecializationStats::clear(); | |
3624 assert(_restart_addr == NULL, "Control point invariant"); | |
3625 if (asynch) { | |
3626 // acquire locks for subsequent manipulations | |
3627 MutexLockerEx x(bitMapLock(), | |
3628 Mutex::_no_safepoint_check_flag); | |
3629 checkpointRootsInitialWork(asynch); | |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3827
diff
changeset
|
3630 // enable ("weak") refs discovery |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3827
diff
changeset
|
3631 rp->enable_discovery(true /*verify_disabled*/, true /*check_no_refs*/); |
0 | 3632 _collectorState = Marking; |
3633 } else { | |
3634 // (Weak) Refs discovery: this is controlled from genCollectedHeap::do_collection | |
3635 // which recognizes if we are a CMS generation, and doesn't try to turn on | |
3636 // discovery; verify that they aren't meddling. | |
3637 assert(!rp->discovery_is_atomic(), | |
3638 "incorrect setting of discovery predicate"); | |
3639 assert(!rp->discovery_enabled(), "genCollectedHeap shouldn't control " | |
3640 "ref discovery for this generation kind"); | |
3641 // already have locks | |
3642 checkpointRootsInitialWork(asynch); | |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3827
diff
changeset
|
3643 // now enable ("weak") refs discovery |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3827
diff
changeset
|
3644 rp->enable_discovery(true /*verify_disabled*/, false /*verify_no_refs*/); |
0 | 3645 _collectorState = Marking; |
3646 } | |
3647 SpecializationStats::print(); | |
3648 } | |
3649 | |
3650 void CMSCollector::checkpointRootsInitialWork(bool asynch) { | |
3651 assert(SafepointSynchronize::is_at_safepoint(), "world should be stopped"); | |
3652 assert(_collectorState == InitialMarking, "just checking"); | |
3653 | |
3654 // If there has not been a GC[n-1] since last GC[n] cycle completed, | |
3655 // precede our marking with a collection of all | |
3656 // younger generations to keep floating garbage to a minimum. | |
3657 // XXX: we won't do this for now -- it's an optimization to be done later. | |
3658 | |
3659 // already have locks | |
3660 assert_lock_strong(bitMapLock()); | |
3661 assert(_markBitMap.isAllClear(), "was reset at end of previous cycle"); | |
3662 | |
3663 // Setup the verification and class unloading state for this | |
3664 // CMS collection cycle. | |
3665 setup_cms_unloading_and_verification_state(); | |
3666 | |
10405 | 3667 NOT_PRODUCT(GCTraceTime t("\ncheckpointRootsInitialWork", |
3668 PrintGCDetails && Verbose, true, _gc_timer_cm);) | |
0 | 3669 if (UseAdaptiveSizePolicy) { |
3670 size_policy()->checkpoint_roots_initial_begin(); | |
3671 } | |
3672 | |
3673 // Reset all the PLAB chunk arrays if necessary. | |
3674 if (_survivor_plab_array != NULL && !CMSPLABRecordAlways) { | |
3675 reset_survivor_plab_arrays(); | |
3676 } | |
3677 | |
3678 ResourceMark rm; | |
3679 HandleMark hm; | |
3680 | |
994
753cf9794df9
6885169: merge of 4957990 and 6863023 causes conflict on do_nmethods
jrose
parents:
993
diff
changeset
|
3681 MarkRefsIntoClosure notOlder(_span, &_markBitMap); |
0 | 3682 GenCollectedHeap* gch = GenCollectedHeap::heap(); |
3683 | |
3684 verify_work_stacks_empty(); | |
3685 verify_overflow_empty(); | |
3686 | |
3687 gch->ensure_parsability(false); // fill TLABs, but no need to retire them | |
3688 // Update the saved marks which may affect the root scans. | |
3689 gch->save_marks(); | |
3690 | |
3691 // weak reference processing has not started yet. | |
3692 ref_processor()->set_enqueuing_is_done(false); | |
3693 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3694 // Need to remember all newly created CLDs, |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3695 // so that we can guarantee that the remark finds them. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3696 ClassLoaderDataGraph::remember_new_clds(true); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3697 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3698 // Whenever a CLD is found, it will be claimed before proceeding to mark |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3699 // the klasses. The claimed marks need to be cleared before marking starts. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3700 ClassLoaderDataGraph::clear_claimed_marks(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3701 |
11973
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
3702 if (CMSPrintEdenSurvivorChunks) { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
3703 print_eden_and_survivor_chunk_arrays(); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
3704 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
3705 |
0 | 3706 { |
3707 COMPILER2_PRESENT(DerivedPointerTableDeactivate dpt_deact;) | |
11975 | 3708 if (CMSParallelInitialMarkEnabled && CollectedHeap::use_parallel_gc_threads()) { |
3709 // The parallel version. | |
3710 FlexibleWorkGang* workers = gch->workers(); | |
3711 assert(workers != NULL, "Need parallel worker threads."); | |
3712 int n_workers = workers->active_workers(); | |
3713 CMSParInitialMarkTask tsk(this, n_workers); | |
3714 gch->set_par_threads(n_workers); | |
3715 initialize_sequential_subtasks_for_young_gen_rescan(n_workers); | |
3716 if (n_workers > 1) { | |
3717 GenCollectedHeap::StrongRootsScope srs(gch); | |
3718 workers->run_task(&tsk); | |
3719 } else { | |
3720 GenCollectedHeap::StrongRootsScope srs(gch); | |
3721 tsk.work(0); | |
3722 } | |
3723 gch->set_par_threads(0); | |
3724 } else { | |
3725 // The serial version. | |
3726 CMKlassClosure klass_closure(¬Older); | |
3727 gch->rem_set()->prepare_for_younger_refs_iterate(false); // Not parallel. | |
3728 gch->gen_process_strong_roots(_cmsGen->level(), | |
3729 true, // younger gens are roots | |
3730 true, // activate StrongRootsScope | |
3731 SharedHeap::ScanningOption(roots_scanning_options()), | |
3732 ¬Older, | |
3733 NULL, | |
3734 &klass_closure); | |
3735 } | |
0 | 3736 } |
3737 | |
3738 // Clear mod-union table; it will be dirtied in the prologue of | |
3739 // CMS generation per each younger generation collection. | |
3740 | |
3741 assert(_modUnionTable.isAllClear(), | |
3742 "Was cleared in most recent final checkpoint phase" | |
3743 " or no bits are set in the gc_prologue before the start of the next " | |
3744 "subsequent marking phase."); | |
3745 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3746 assert(_ct->klass_rem_set()->mod_union_is_clear(), "Must be"); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
3747 |
0 | 3748 // Save the end of the used_region of the constituent generations |
3749 // to be used to limit the extent of sweep in each generation. | |
3750 save_sweep_limits(); | |
3751 if (UseAdaptiveSizePolicy) { | |
3752 size_policy()->checkpoint_roots_initial_end(gch->gc_cause()); | |
3753 } | |
3754 verify_overflow_empty(); | |
3755 } | |
3756 | |
3757 bool CMSCollector::markFromRoots(bool asynch) { | |
3758 // we might be tempted to assert that: | |
3759 // assert(asynch == !SafepointSynchronize::is_at_safepoint(), | |
3760 // "inconsistent argument?"); | |
3761 // However that wouldn't be right, because it's possible that | |
3762 // a safepoint is indeed in progress as a younger generation | |
3763 // stop-the-world GC happens even as we mark in this generation. | |
3764 assert(_collectorState == Marking, "inconsistent state?"); | |
3765 check_correct_thread_executing(); | |
3766 verify_overflow_empty(); | |
3767 | |
3768 bool res; | |
3769 if (asynch) { | |
3770 | |
3771 // Start the timers for adaptive size policy for the concurrent phases | |
3772 // Do it here so that the foreground MS can use the concurrent | |
3773 // timer since a foreground MS might has the sweep done concurrently | |
3774 // or STW. | |
3775 if (UseAdaptiveSizePolicy) { | |
3776 size_policy()->concurrent_marking_begin(); | |
3777 } | |
3778 | |
3779 // Weak ref discovery note: We may be discovering weak | |
3780 // refs in this generation concurrent (but interleaved) with | |
3781 // weak ref discovery by a younger generation collector. | |
3782 | |
3783 CMSTokenSyncWithLocks ts(true, bitMapLock()); | |
3784 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
3785 CMSPhaseAccounting pa(this, "mark", !PrintGCDetails); | |
3786 res = markFromRootsWork(asynch); | |
3787 if (res) { | |
3788 _collectorState = Precleaning; | |
3789 } else { // We failed and a foreground collection wants to take over | |
3790 assert(_foregroundGCIsActive, "internal state inconsistency"); | |
3791 assert(_restart_addr == NULL, "foreground will restart from scratch"); | |
3792 if (PrintGCDetails) { | |
3793 gclog_or_tty->print_cr("bailing out to foreground collection"); | |
3794 } | |
3795 } | |
3796 if (UseAdaptiveSizePolicy) { | |
3797 size_policy()->concurrent_marking_end(); | |
3798 } | |
3799 } else { | |
3800 assert(SafepointSynchronize::is_at_safepoint(), | |
3801 "inconsistent with asynch == false"); | |
3802 if (UseAdaptiveSizePolicy) { | |
3803 size_policy()->ms_collection_marking_begin(); | |
3804 } | |
3805 // already have locks | |
3806 res = markFromRootsWork(asynch); | |
3807 _collectorState = FinalMarking; | |
3808 if (UseAdaptiveSizePolicy) { | |
3809 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
3810 size_policy()->ms_collection_marking_end(gch->gc_cause()); | |
3811 } | |
3812 } | |
3813 verify_overflow_empty(); | |
3814 return res; | |
3815 } | |
3816 | |
3817 bool CMSCollector::markFromRootsWork(bool asynch) { | |
3818 // iterate over marked bits in bit map, doing a full scan and mark | |
3819 // from these roots using the following algorithm: | |
3820 // . if oop is to the right of the current scan pointer, | |
3821 // mark corresponding bit (we'll process it later) | |
3822 // . else (oop is to left of current scan pointer) | |
3823 // push oop on marking stack | |
3824 // . drain the marking stack | |
3825 | |
3826 // Note that when we do a marking step we need to hold the | |
3827 // bit map lock -- recall that direct allocation (by mutators) | |
3828 // and promotion (by younger generation collectors) is also | |
3829 // marking the bit map. [the so-called allocate live policy.] | |
3830 // Because the implementation of bit map marking is not | |
3831 // robust wrt simultaneous marking of bits in the same word, | |
3832 // we need to make sure that there is no such interference | |
3833 // between concurrent such updates. | |
3834 | |
3835 // already have locks | |
3836 assert_lock_strong(bitMapLock()); | |
3837 | |
3838 verify_work_stacks_empty(); | |
3839 verify_overflow_empty(); | |
3840 bool result = false; | |
1284 | 3841 if (CMSConcurrentMTEnabled && ConcGCThreads > 0) { |
0 | 3842 result = do_marking_mt(asynch); |
3843 } else { | |
3844 result = do_marking_st(asynch); | |
3845 } | |
3846 return result; | |
3847 } | |
3848 | |
3849 // Forward decl | |
3850 class CMSConcMarkingTask; | |
3851 | |
3852 class CMSConcMarkingTerminator: public ParallelTaskTerminator { | |
3853 CMSCollector* _collector; | |
3854 CMSConcMarkingTask* _task; | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3855 public: |
0 | 3856 virtual void yield(); |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3857 |
0 | 3858 // "n_threads" is the number of threads to be terminated. |
3859 // "queue_set" is a set of work queues of other threads. | |
3860 // "collector" is the CMS collector associated with this task terminator. | |
3861 // "yield" indicates whether we need the gang as a whole to yield. | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3862 CMSConcMarkingTerminator(int n_threads, TaskQueueSetSuper* queue_set, CMSCollector* collector) : |
0 | 3863 ParallelTaskTerminator(n_threads, queue_set), |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3864 _collector(collector) { } |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3865 |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3866 void set_task(CMSConcMarkingTask* task) { |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3867 _task = task; |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3868 } |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3869 }; |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3870 |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3871 class CMSConcMarkingTerminatorTerminator: public TerminatorTerminator { |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3872 CMSConcMarkingTask* _task; |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3873 public: |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3874 bool should_exit_termination(); |
0 | 3875 void set_task(CMSConcMarkingTask* task) { |
3876 _task = task; | |
3877 } | |
3878 }; | |
3879 | |
3880 // MT Concurrent Marking Task | |
3881 class CMSConcMarkingTask: public YieldingFlexibleGangTask { | |
3882 CMSCollector* _collector; | |
3883 int _n_workers; // requested/desired # workers | |
3884 bool _asynch; | |
3885 bool _result; | |
3886 CompactibleFreeListSpace* _cms_space; | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3887 char _pad_front[64]; // padding to ... |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3888 HeapWord* _global_finger; // ... avoid sharing cache line |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3889 char _pad_back[64]; |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
3890 HeapWord* _restart_addr; |
0 | 3891 |
3892 // Exposed here for yielding support | |
3893 Mutex* const _bit_map_lock; | |
3894 | |
3895 // The per thread work queues, available here for stealing | |
3896 OopTaskQueueSet* _task_queues; | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3897 |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3898 // Termination (and yielding) support |
0 | 3899 CMSConcMarkingTerminator _term; |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3900 CMSConcMarkingTerminatorTerminator _term_term; |
0 | 3901 |
3902 public: | |
3903 CMSConcMarkingTask(CMSCollector* collector, | |
3904 CompactibleFreeListSpace* cms_space, | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
3905 bool asynch, |
0 | 3906 YieldingFlexibleWorkGang* workers, |
3907 OopTaskQueueSet* task_queues): | |
3908 YieldingFlexibleGangTask("Concurrent marking done multi-threaded"), | |
3909 _collector(collector), | |
3910 _cms_space(cms_space), | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
3911 _asynch(asynch), _n_workers(0), _result(true), |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
3912 _task_queues(task_queues), |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3913 _term(_n_workers, task_queues, _collector), |
0 | 3914 _bit_map_lock(collector->bitMapLock()) |
3915 { | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
3916 _requested_size = _n_workers; |
0 | 3917 _term.set_task(this); |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3918 _term_term.set_task(this); |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
3919 _restart_addr = _global_finger = _cms_space->bottom(); |
0 | 3920 } |
3921 | |
3922 | |
3923 OopTaskQueueSet* task_queues() { return _task_queues; } | |
3924 | |
3925 OopTaskQueue* work_queue(int i) { return task_queues()->queue(i); } | |
3926 | |
3927 HeapWord** global_finger_addr() { return &_global_finger; } | |
3928 | |
3929 CMSConcMarkingTerminator* terminator() { return &_term; } | |
3930 | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
3931 virtual void set_for_termination(int active_workers) { |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
3932 terminator()->reset_for_reuse(active_workers); |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
3933 } |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
3934 |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
3935 void work(uint worker_id); |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3936 bool should_yield() { |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3937 return ConcurrentMarkSweepThread::should_yield() |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3938 && !_collector->foregroundGCIsActive() |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3939 && _asynch; |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3940 } |
0 | 3941 |
3942 virtual void coordinator_yield(); // stuff done by coordinator | |
3943 bool result() { return _result; } | |
3944 | |
3945 void reset(HeapWord* ra) { | |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
3946 assert(_global_finger >= _cms_space->end(), "Postcondition of ::work(i)"); |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
3947 _restart_addr = _global_finger = ra; |
0 | 3948 _term.reset_for_reuse(); |
3949 } | |
3950 | |
3951 static bool get_work_from_overflow_stack(CMSMarkStack* ovflw_stk, | |
3952 OopTaskQueue* work_q); | |
3953 | |
3954 private: | |
3955 void do_scan_and_mark(int i, CompactibleFreeListSpace* sp); | |
3956 void do_work_steal(int i); | |
3957 void bump_global_finger(HeapWord* f); | |
3958 }; | |
3959 | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3960 bool CMSConcMarkingTerminatorTerminator::should_exit_termination() { |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3961 assert(_task != NULL, "Error"); |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3962 return _task->yielding(); |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3963 // Note that we do not need the disjunct || _task->should_yield() above |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3964 // because we want terminating threads to yield only if the task |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3965 // is already in the midst of yielding, which happens only after at least one |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3966 // thread has yielded. |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3967 } |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3968 |
0 | 3969 void CMSConcMarkingTerminator::yield() { |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
3970 if (_task->should_yield()) { |
0 | 3971 _task->yield(); |
3972 } else { | |
3973 ParallelTaskTerminator::yield(); | |
3974 } | |
3975 } | |
3976 | |
3977 //////////////////////////////////////////////////////////////// | |
3978 // Concurrent Marking Algorithm Sketch | |
3979 //////////////////////////////////////////////////////////////// | |
3980 // Until all tasks exhausted (both spaces): | |
3981 // -- claim next available chunk | |
3982 // -- bump global finger via CAS | |
3983 // -- find first object that starts in this chunk | |
3984 // and start scanning bitmap from that position | |
3985 // -- scan marked objects for oops | |
3986 // -- CAS-mark target, and if successful: | |
3987 // . if target oop is above global finger (volatile read) | |
3988 // nothing to do | |
3989 // . if target oop is in chunk and above local finger | |
3990 // then nothing to do | |
3991 // . else push on work-queue | |
3992 // -- Deal with possible overflow issues: | |
3993 // . local work-queue overflow causes stuff to be pushed on | |
3994 // global (common) overflow queue | |
3995 // . always first empty local work queue | |
3996 // . then get a batch of oops from global work queue if any | |
3997 // . then do work stealing | |
3998 // -- When all tasks claimed (both spaces) | |
3999 // and local work queue empty, | |
4000 // then in a loop do: | |
4001 // . check global overflow stack; steal a batch of oops and trace | |
4002 // . try to steal from other threads oif GOS is empty | |
4003 // . if neither is available, offer termination | |
4004 // -- Terminate and return result | |
4005 // | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
4006 void CMSConcMarkingTask::work(uint worker_id) { |
0 | 4007 elapsedTimer _timer; |
4008 ResourceMark rm; | |
4009 HandleMark hm; | |
4010 | |
4011 DEBUG_ONLY(_collector->verify_overflow_empty();) | |
4012 | |
4013 // Before we begin work, our work queue should be empty | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
4014 assert(work_queue(worker_id)->size() == 0, "Expected to be empty"); |
0 | 4015 // Scan the bitmap covering _cms_space, tracing through grey objects. |
4016 _timer.start(); | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
4017 do_scan_and_mark(worker_id, _cms_space); |
0 | 4018 _timer.stop(); |
4019 if (PrintCMSStatistics != 0) { | |
4020 gclog_or_tty->print_cr("Finished cms space scanning in %dth thread: %3.3f sec", | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
4021 worker_id, _timer.seconds()); |
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
4022 // XXX: need xxx/xxx type of notation, two timers |
0 | 4023 } |
4024 | |
4025 // ... do work stealing | |
4026 _timer.reset(); | |
4027 _timer.start(); | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
4028 do_work_steal(worker_id); |
0 | 4029 _timer.stop(); |
4030 if (PrintCMSStatistics != 0) { | |
4031 gclog_or_tty->print_cr("Finished work stealing in %dth thread: %3.3f sec", | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
4032 worker_id, _timer.seconds()); |
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
4033 // XXX: need xxx/xxx type of notation, two timers |
0 | 4034 } |
4035 assert(_collector->_markStack.isEmpty(), "Should have been emptied"); | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
4036 assert(work_queue(worker_id)->size() == 0, "Should have been emptied"); |
0 | 4037 // Note that under the current task protocol, the |
4038 // following assertion is true even of the spaces | |
4039 // expanded since the completion of the concurrent | |
4040 // marking. XXX This will likely change under a strict | |
4041 // ABORT semantics. | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4042 // After perm removal the comparison was changed to |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4043 // greater than or equal to from strictly greater than. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4044 // Before perm removal the highest address sweep would |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4045 // have been at the end of perm gen but now is at the |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4046 // end of the tenured gen. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4047 assert(_global_finger >= _cms_space->end(), |
0 | 4048 "All tasks have been completed"); |
4049 DEBUG_ONLY(_collector->verify_overflow_empty();) | |
4050 } | |
4051 | |
4052 void CMSConcMarkingTask::bump_global_finger(HeapWord* f) { | |
4053 HeapWord* read = _global_finger; | |
4054 HeapWord* cur = read; | |
4055 while (f > read) { | |
4056 cur = read; | |
4057 read = (HeapWord*) Atomic::cmpxchg_ptr(f, &_global_finger, cur); | |
4058 if (cur == read) { | |
4059 // our cas succeeded | |
4060 assert(_global_finger >= f, "protocol consistency"); | |
4061 break; | |
4062 } | |
4063 } | |
4064 } | |
4065 | |
4066 // This is really inefficient, and should be redone by | |
4067 // using (not yet available) block-read and -write interfaces to the | |
4068 // stack and the work_queue. XXX FIX ME !!! | |
4069 bool CMSConcMarkingTask::get_work_from_overflow_stack(CMSMarkStack* ovflw_stk, | |
4070 OopTaskQueue* work_q) { | |
4071 // Fast lock-free check | |
4072 if (ovflw_stk->length() == 0) { | |
4073 return false; | |
4074 } | |
4075 assert(work_q->size() == 0, "Shouldn't steal"); | |
4076 MutexLockerEx ml(ovflw_stk->par_lock(), | |
4077 Mutex::_no_safepoint_check_flag); | |
4078 // Grab up to 1/4 the size of the work queue | |
679
cea947c8a988
6819891: ParNew: Fix work queue overflow code to deal correctly with +UseCompressedOops
ysr
parents:
628
diff
changeset
|
4079 size_t num = MIN2((size_t)(work_q->max_elems() - work_q->size())/4, |
0 | 4080 (size_t)ParGCDesiredObjsFromOverflowList); |
4081 num = MIN2(num, ovflw_stk->length()); | |
4082 for (int i = (int) num; i > 0; i--) { | |
4083 oop cur = ovflw_stk->pop(); | |
4084 assert(cur != NULL, "Counted wrong?"); | |
4085 work_q->push(cur); | |
4086 } | |
4087 return num > 0; | |
4088 } | |
4089 | |
4090 void CMSConcMarkingTask::do_scan_and_mark(int i, CompactibleFreeListSpace* sp) { | |
4091 SequentialSubTasksDone* pst = sp->conc_par_seq_tasks(); | |
4092 int n_tasks = pst->n_tasks(); | |
4093 // We allow that there may be no tasks to do here because | |
4094 // we are restarting after a stack overflow. | |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4095 assert(pst->valid() || n_tasks == 0, "Uninitialized use?"); |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
4096 uint nth_task = 0; |
0 | 4097 |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4098 HeapWord* aligned_start = sp->bottom(); |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4099 if (sp->used_region().contains(_restart_addr)) { |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4100 // Align down to a card boundary for the start of 0th task |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4101 // for this space. |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4102 aligned_start = |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4103 (HeapWord*)align_size_down((uintptr_t)_restart_addr, |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4104 CardTableModRefBS::card_size); |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4105 } |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4106 |
0 | 4107 size_t chunk_size = sp->marking_task_size(); |
4108 while (!pst->is_task_claimed(/* reference */ nth_task)) { | |
4109 // Having claimed the nth task in this space, | |
4110 // compute the chunk that it corresponds to: | |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4111 MemRegion span = MemRegion(aligned_start + nth_task*chunk_size, |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4112 aligned_start + (nth_task+1)*chunk_size); |
0 | 4113 // Try and bump the global finger via a CAS; |
4114 // note that we need to do the global finger bump | |
4115 // _before_ taking the intersection below, because | |
4116 // the task corresponding to that region will be | |
4117 // deemed done even if the used_region() expands | |
4118 // because of allocation -- as it almost certainly will | |
4119 // during start-up while the threads yield in the | |
4120 // closure below. | |
4121 HeapWord* finger = span.end(); | |
4122 bump_global_finger(finger); // atomically | |
4123 // There are null tasks here corresponding to chunks | |
4124 // beyond the "top" address of the space. | |
4125 span = span.intersection(sp->used_region()); | |
4126 if (!span.is_empty()) { // Non-null task | |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4127 HeapWord* prev_obj; |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4128 assert(!span.contains(_restart_addr) || nth_task == 0, |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4129 "Inconsistency"); |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4130 if (nth_task == 0) { |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4131 // For the 0th task, we'll not need to compute a block_start. |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4132 if (span.contains(_restart_addr)) { |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4133 // In the case of a restart because of stack overflow, |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4134 // we might additionally skip a chunk prefix. |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4135 prev_obj = _restart_addr; |
0 | 4136 } else { |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4137 prev_obj = span.start(); |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4138 } |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4139 } else { |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4140 // We want to skip the first object because |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4141 // the protocol is to scan any object in its entirety |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4142 // that _starts_ in this span; a fortiori, any |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4143 // object starting in an earlier span is scanned |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4144 // as part of an earlier claimed task. |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4145 // Below we use the "careful" version of block_start |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4146 // so we do not try to navigate uninitialized objects. |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4147 prev_obj = sp->block_start_careful(span.start()); |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4148 // Below we use a variant of block_size that uses the |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4149 // Printezis bits to avoid waiting for allocated |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4150 // objects to become initialized/parsable. |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4151 while (prev_obj < span.start()) { |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4152 size_t sz = sp->block_size_no_stall(prev_obj, _collector); |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4153 if (sz > 0) { |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4154 prev_obj += sz; |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4155 } else { |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4156 // In this case we may end up doing a bit of redundant |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4157 // scanning, but that appears unavoidable, short of |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4158 // locking the free list locks; see bug 6324141. |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4159 break; |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4160 } |
0 | 4161 } |
4162 } | |
4163 if (prev_obj < span.end()) { | |
4164 MemRegion my_span = MemRegion(prev_obj, span.end()); | |
4165 // Do the marking work within a non-empty span -- | |
4166 // the last argument to the constructor indicates whether the | |
4167 // iteration should be incremental with periodic yields. | |
4168 Par_MarkFromRootsClosure cl(this, _collector, my_span, | |
4169 &_collector->_markBitMap, | |
4170 work_queue(i), | |
4171 &_collector->_markStack, | |
4172 _asynch); | |
4173 _collector->_markBitMap.iterate(&cl, my_span.start(), my_span.end()); | |
4174 } // else nothing to do for this task | |
4175 } // else nothing to do for this task | |
4176 } | |
4177 // We'd be tempted to assert here that since there are no | |
4178 // more tasks left to claim in this space, the global_finger | |
4179 // must exceed space->top() and a fortiori space->end(). However, | |
4180 // that would not quite be correct because the bumping of | |
4181 // global_finger occurs strictly after the claiming of a task, | |
4182 // so by the time we reach here the global finger may not yet | |
4183 // have been bumped up by the thread that claimed the last | |
4184 // task. | |
4185 pst->all_tasks_completed(); | |
4186 } | |
4187 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4188 class Par_ConcMarkingClosure: public CMSOopClosure { |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4189 private: |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4190 CMSCollector* _collector; |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4191 CMSConcMarkingTask* _task; |
0 | 4192 MemRegion _span; |
4193 CMSBitMap* _bit_map; | |
4194 CMSMarkStack* _overflow_stack; | |
4195 OopTaskQueue* _work_queue; | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4196 protected: |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4197 DO_OOP_WORK_DEFN |
0 | 4198 public: |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4199 Par_ConcMarkingClosure(CMSCollector* collector, CMSConcMarkingTask* task, OopTaskQueue* work_queue, |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4200 CMSBitMap* bit_map, CMSMarkStack* overflow_stack): |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4201 CMSOopClosure(collector->ref_processor()), |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4202 _collector(collector), |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4203 _task(task), |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4204 _span(collector->_span), |
0 | 4205 _work_queue(work_queue), |
4206 _bit_map(bit_map), | |
935 | 4207 _overflow_stack(overflow_stack) |
4208 { } | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4209 virtual void do_oop(oop* p); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4210 virtual void do_oop(narrowOop* p); |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4211 |
0 | 4212 void trim_queue(size_t max); |
4213 void handle_stack_overflow(HeapWord* lost); | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4214 void do_yield_check() { |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4215 if (_task->should_yield()) { |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4216 _task->yield(); |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4217 } |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4218 } |
0 | 4219 }; |
4220 | |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4221 // Grey object scanning during work stealing phase -- |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4222 // the salient assumption here is that any references |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4223 // that are in these stolen objects being scanned must |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4224 // already have been initialized (else they would not have |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4225 // been published), so we do not need to check for |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4226 // uninitialized objects before pushing here. |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4227 void Par_ConcMarkingClosure::do_oop(oop obj) { |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4228 assert(obj->is_oop_or_null(true), "expected an oop or NULL"); |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4229 HeapWord* addr = (HeapWord*)obj; |
0 | 4230 // Check if oop points into the CMS generation |
4231 // and is not marked | |
4232 if (_span.contains(addr) && !_bit_map->isMarked(addr)) { | |
4233 // a white object ... | |
4234 // If we manage to "claim" the object, by being the | |
4235 // first thread to mark it, then we push it on our | |
4236 // marking stack | |
4237 if (_bit_map->par_mark(addr)) { // ... now grey | |
4238 // push on work queue (grey set) | |
4239 bool simulate_overflow = false; | |
4240 NOT_PRODUCT( | |
4241 if (CMSMarkStackOverflowALot && | |
4242 _collector->simulate_overflow()) { | |
4243 // simulate a stack overflow | |
4244 simulate_overflow = true; | |
4245 } | |
4246 ) | |
4247 if (simulate_overflow || | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4248 !(_work_queue->push(obj) || _overflow_stack->par_push(obj))) { |
0 | 4249 // stack overflow |
4250 if (PrintCMSStatistics != 0) { | |
4251 gclog_or_tty->print_cr("CMS marking stack overflow (benign) at " | |
4252 SIZE_FORMAT, _overflow_stack->capacity()); | |
4253 } | |
4254 // We cannot assert that the overflow stack is full because | |
4255 // it may have been emptied since. | |
4256 assert(simulate_overflow || | |
4257 _work_queue->size() == _work_queue->max_elems(), | |
4258 "Else push should have succeeded"); | |
4259 handle_stack_overflow(addr); | |
4260 } | |
4261 } // Else, some other thread got there first | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4262 do_yield_check(); |
0 | 4263 } |
4264 } | |
4265 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4266 void Par_ConcMarkingClosure::do_oop(oop* p) { Par_ConcMarkingClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4267 void Par_ConcMarkingClosure::do_oop(narrowOop* p) { Par_ConcMarkingClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4268 |
0 | 4269 void Par_ConcMarkingClosure::trim_queue(size_t max) { |
4270 while (_work_queue->size() > max) { | |
4271 oop new_oop; | |
4272 if (_work_queue->pop_local(new_oop)) { | |
4273 assert(new_oop->is_oop(), "Should be an oop"); | |
4274 assert(_bit_map->isMarked((HeapWord*)new_oop), "Grey object"); | |
4275 assert(_span.contains((HeapWord*)new_oop), "Not in span"); | |
4276 new_oop->oop_iterate(this); // do_oop() above | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4277 do_yield_check(); |
0 | 4278 } |
4279 } | |
4280 } | |
4281 | |
4282 // Upon stack overflow, we discard (part of) the stack, | |
4283 // remembering the least address amongst those discarded | |
4284 // in CMSCollector's _restart_address. | |
4285 void Par_ConcMarkingClosure::handle_stack_overflow(HeapWord* lost) { | |
4286 // We need to do this under a mutex to prevent other | |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
4287 // workers from interfering with the work done below. |
0 | 4288 MutexLockerEx ml(_overflow_stack->par_lock(), |
4289 Mutex::_no_safepoint_check_flag); | |
4290 // Remember the least grey address discarded | |
4291 HeapWord* ra = (HeapWord*)_overflow_stack->least_value(lost); | |
4292 _collector->lower_restart_addr(ra); | |
4293 _overflow_stack->reset(); // discard stack contents | |
4294 _overflow_stack->expand(); // expand the stack if possible | |
4295 } | |
4296 | |
4297 | |
4298 void CMSConcMarkingTask::do_work_steal(int i) { | |
4299 OopTaskQueue* work_q = work_queue(i); | |
4300 oop obj_to_scan; | |
4301 CMSBitMap* bm = &(_collector->_markBitMap); | |
4302 CMSMarkStack* ovflw = &(_collector->_markStack); | |
4303 int* seed = _collector->hash_seed(i); | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4304 Par_ConcMarkingClosure cl(_collector, this, work_q, bm, ovflw); |
0 | 4305 while (true) { |
4306 cl.trim_queue(0); | |
4307 assert(work_q->size() == 0, "Should have been emptied above"); | |
4308 if (get_work_from_overflow_stack(ovflw, work_q)) { | |
4309 // Can't assert below because the work obtained from the | |
4310 // overflow stack may already have been stolen from us. | |
4311 // assert(work_q->size() > 0, "Work from overflow stack"); | |
4312 continue; | |
4313 } else if (task_queues()->steal(i, seed, /* reference */ obj_to_scan)) { | |
4314 assert(obj_to_scan->is_oop(), "Should be an oop"); | |
4315 assert(bm->isMarked((HeapWord*)obj_to_scan), "Grey object"); | |
4316 obj_to_scan->oop_iterate(&cl); | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4317 } else if (terminator()->offer_termination(&_term_term)) { |
0 | 4318 assert(work_q->size() == 0, "Impossible!"); |
4319 break; | |
1837
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4320 } else if (yielding() || should_yield()) { |
c99c53f07c14
6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
ysr
parents:
1836
diff
changeset
|
4321 yield(); |
0 | 4322 } |
4323 } | |
4324 } | |
4325 | |
4326 // This is run by the CMS (coordinator) thread. | |
4327 void CMSConcMarkingTask::coordinator_yield() { | |
4328 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
4329 "CMS thread should hold CMS token"); | |
4330 // First give up the locks, then yield, then re-lock | |
4331 // We should probably use a constructor/destructor idiom to | |
4332 // do this unlock/lock or modify the MutexUnlocker class to | |
4333 // serve our purpose. XXX | |
4334 assert_lock_strong(_bit_map_lock); | |
4335 _bit_map_lock->unlock(); | |
4336 ConcurrentMarkSweepThread::desynchronize(true); | |
4337 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
4338 _collector->stopTimer(); | |
4339 if (PrintCMSStatistics != 0) { | |
4340 _collector->incrementYields(); | |
4341 } | |
4342 _collector->icms_wait(); | |
4343 | |
4344 // It is possible for whichever thread initiated the yield request | |
4345 // not to get a chance to wake up and take the bitmap lock between | |
4346 // this thread releasing it and reacquiring it. So, while the | |
4347 // should_yield() flag is on, let's sleep for a bit to give the | |
4348 // other thread a chance to wake up. The limit imposed on the number | |
4349 // of iterations is defensive, to avoid any unforseen circumstances | |
4350 // putting us into an infinite loop. Since it's always been this | |
4351 // (coordinator_yield()) method that was observed to cause the | |
4352 // problem, we are using a parameter (CMSCoordinatorYieldSleepCount) | |
4353 // which is by default non-zero. For the other seven methods that | |
4354 // also perform the yield operation, as are using a different | |
4355 // parameter (CMSYieldSleepCount) which is by default zero. This way we | |
4356 // can enable the sleeping for those methods too, if necessary. | |
4357 // See 6442774. | |
4358 // | |
4359 // We really need to reconsider the synchronization between the GC | |
4360 // thread and the yield-requesting threads in the future and we | |
4361 // should really use wait/notify, which is the recommended | |
4362 // way of doing this type of interaction. Additionally, we should | |
4363 // consolidate the eight methods that do the yield operation and they | |
14309 | 4364 // are almost identical into one for better maintainability and |
0 | 4365 // readability. See 6445193. |
4366 // | |
4367 // Tony 2006.06.29 | |
4368 for (unsigned i = 0; i < CMSCoordinatorYieldSleepCount && | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4369 ConcurrentMarkSweepThread::should_yield() && |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
4370 !CMSCollector::foregroundGCIsActive(); ++i) { |
0 | 4371 os::sleep(Thread::current(), 1, false); |
4372 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
4373 } | |
4374 | |
4375 ConcurrentMarkSweepThread::synchronize(true); | |
4376 _bit_map_lock->lock_without_safepoint_check(); | |
4377 _collector->startTimer(); | |
4378 } | |
4379 | |
4380 bool CMSCollector::do_marking_mt(bool asynch) { | |
1284 | 4381 assert(ConcGCThreads > 0 && conc_workers() != NULL, "precondition"); |
4095
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
4382 int num_workers = AdaptiveSizePolicy::calc_active_conc_workers( |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
4383 conc_workers()->total_workers(), |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
4384 conc_workers()->active_workers(), |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
4385 Threads::number_of_non_daemon_threads()); |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
4386 conc_workers()->set_active_workers(num_workers); |
0 | 4387 |
4388 CompactibleFreeListSpace* cms_space = _cmsGen->cmsSpace(); | |
4389 | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
4390 CMSConcMarkingTask tsk(this, |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
4391 cms_space, |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
4392 asynch, |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
4393 conc_workers(), |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
4394 task_queues()); |
0 | 4395 |
4396 // Since the actual number of workers we get may be different | |
4397 // from the number we requested above, do we need to do anything different | |
4398 // below? In particular, may be we need to subclass the SequantialSubTasksDone | |
4399 // class?? XXX | |
4400 cms_space ->initialize_sequential_subtasks_for_marking(num_workers); | |
4401 | |
4402 // Refs discovery is already non-atomic. | |
4403 assert(!ref_processor()->discovery_is_atomic(), "Should be non-atomic"); | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
4404 assert(ref_processor()->discovery_is_mt(), "Discovery should be MT"); |
0 | 4405 conc_workers()->start_task(&tsk); |
4406 while (tsk.yielded()) { | |
4407 tsk.coordinator_yield(); | |
4408 conc_workers()->continue_task(&tsk); | |
4409 } | |
4410 // If the task was aborted, _restart_addr will be non-NULL | |
4411 assert(tsk.completed() || _restart_addr != NULL, "Inconsistency"); | |
4412 while (_restart_addr != NULL) { | |
4413 // XXX For now we do not make use of ABORTED state and have not | |
4414 // yet implemented the right abort semantics (even in the original | |
4415 // single-threaded CMS case). That needs some more investigation | |
4416 // and is deferred for now; see CR# TBF. 07252005YSR. XXX | |
4417 assert(!CMSAbortSemantics || tsk.aborted(), "Inconsistency"); | |
4418 // If _restart_addr is non-NULL, a marking stack overflow | |
605 | 4419 // occurred; we need to do a fresh marking iteration from the |
0 | 4420 // indicated restart address. |
4421 if (_foregroundGCIsActive && asynch) { | |
4422 // We may be running into repeated stack overflows, having | |
4423 // reached the limit of the stack size, while making very | |
4424 // slow forward progress. It may be best to bail out and | |
4425 // let the foreground collector do its job. | |
4426 // Clear _restart_addr, so that foreground GC | |
4427 // works from scratch. This avoids the headache of | |
4428 // a "rescan" which would otherwise be needed because | |
4429 // of the dirty mod union table & card table. | |
4430 _restart_addr = NULL; | |
4431 return false; | |
4432 } | |
4433 // Adjust the task to restart from _restart_addr | |
4434 tsk.reset(_restart_addr); | |
4435 cms_space ->initialize_sequential_subtasks_for_marking(num_workers, | |
4436 _restart_addr); | |
4437 _restart_addr = NULL; | |
4438 // Get the workers going again | |
4439 conc_workers()->start_task(&tsk); | |
4440 while (tsk.yielded()) { | |
4441 tsk.coordinator_yield(); | |
4442 conc_workers()->continue_task(&tsk); | |
4443 } | |
4444 } | |
4445 assert(tsk.completed(), "Inconsistency"); | |
4446 assert(tsk.result() == true, "Inconsistency"); | |
4447 return true; | |
4448 } | |
4449 | |
4450 bool CMSCollector::do_marking_st(bool asynch) { | |
4451 ResourceMark rm; | |
4452 HandleMark hm; | |
4453 | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
4454 // Temporarily make refs discovery single threaded (non-MT) |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
4455 ReferenceProcessorMTDiscoveryMutator rp_mut_discovery(ref_processor(), false); |
0 | 4456 MarkFromRootsClosure markFromRootsClosure(this, _span, &_markBitMap, |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4457 &_markStack, CMSYield && asynch); |
0 | 4458 // the last argument to iterate indicates whether the iteration |
4459 // should be incremental with periodic yields. | |
4460 _markBitMap.iterate(&markFromRootsClosure); | |
4461 // If _restart_addr is non-NULL, a marking stack overflow | |
605 | 4462 // occurred; we need to do a fresh iteration from the |
0 | 4463 // indicated restart address. |
4464 while (_restart_addr != NULL) { | |
4465 if (_foregroundGCIsActive && asynch) { | |
4466 // We may be running into repeated stack overflows, having | |
4467 // reached the limit of the stack size, while making very | |
4468 // slow forward progress. It may be best to bail out and | |
4469 // let the foreground collector do its job. | |
4470 // Clear _restart_addr, so that foreground GC | |
4471 // works from scratch. This avoids the headache of | |
4472 // a "rescan" which would otherwise be needed because | |
4473 // of the dirty mod union table & card table. | |
4474 _restart_addr = NULL; | |
4475 return false; // indicating failure to complete marking | |
4476 } | |
4477 // Deal with stack overflow: | |
4478 // we restart marking from _restart_addr | |
4479 HeapWord* ra = _restart_addr; | |
4480 markFromRootsClosure.reset(ra); | |
4481 _restart_addr = NULL; | |
4482 _markBitMap.iterate(&markFromRootsClosure, ra, _span.end()); | |
4483 } | |
4484 return true; | |
4485 } | |
4486 | |
4487 void CMSCollector::preclean() { | |
4488 check_correct_thread_executing(); | |
4489 assert(Thread::current()->is_ConcurrentGC_thread(), "Wrong thread"); | |
4490 verify_work_stacks_empty(); | |
4491 verify_overflow_empty(); | |
4492 _abort_preclean = false; | |
4493 if (CMSPrecleaningEnabled) { | |
11973
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
4494 if (!CMSEdenChunksRecordAlways) { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
4495 _eden_chunk_index = 0; |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
4496 } |
0 | 4497 size_t used = get_eden_used(); |
4498 size_t capacity = get_eden_capacity(); | |
4499 // Don't start sampling unless we will get sufficiently | |
4500 // many samples. | |
4501 if (used < (capacity/(CMSScheduleRemarkSamplingRatio * 100) | |
4502 * CMSScheduleRemarkEdenPenetration)) { | |
4503 _start_sampling = true; | |
4504 } else { | |
4505 _start_sampling = false; | |
4506 } | |
4507 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
4508 CMSPhaseAccounting pa(this, "preclean", !PrintGCDetails); | |
4509 preclean_work(CMSPrecleanRefLists1, CMSPrecleanSurvivors1); | |
4510 } | |
4511 CMSTokenSync x(true); // is cms thread | |
4512 if (CMSPrecleaningEnabled) { | |
4513 sample_eden(); | |
4514 _collectorState = AbortablePreclean; | |
4515 } else { | |
4516 _collectorState = FinalMarking; | |
4517 } | |
4518 verify_work_stacks_empty(); | |
4519 verify_overflow_empty(); | |
4520 } | |
4521 | |
4522 // Try and schedule the remark such that young gen | |
4523 // occupancy is CMSScheduleRemarkEdenPenetration %. | |
4524 void CMSCollector::abortable_preclean() { | |
4525 check_correct_thread_executing(); | |
4526 assert(CMSPrecleaningEnabled, "Inconsistent control state"); | |
4527 assert(_collectorState == AbortablePreclean, "Inconsistent control state"); | |
4528 | |
4529 // If Eden's current occupancy is below this threshold, | |
4530 // immediately schedule the remark; else preclean | |
4531 // past the next scavenge in an effort to | |
14309 | 4532 // schedule the pause as described above. By choosing |
0 | 4533 // CMSScheduleRemarkEdenSizeThreshold >= max eden size |
4534 // we will never do an actual abortable preclean cycle. | |
4535 if (get_eden_used() > CMSScheduleRemarkEdenSizeThreshold) { | |
4536 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
4537 CMSPhaseAccounting pa(this, "abortable-preclean", !PrintGCDetails); | |
4538 // We need more smarts in the abortable preclean | |
4539 // loop below to deal with cases where allocation | |
4540 // in young gen is very very slow, and our precleaning | |
4541 // is running a losing race against a horde of | |
4542 // mutators intent on flooding us with CMS updates | |
4543 // (dirty cards). | |
4544 // One, admittedly dumb, strategy is to give up | |
4545 // after a certain number of abortable precleaning loops | |
4546 // or after a certain maximum time. We want to make | |
4547 // this smarter in the next iteration. | |
4548 // XXX FIX ME!!! YSR | |
4549 size_t loops = 0, workdone = 0, cumworkdone = 0, waited = 0; | |
4550 while (!(should_abort_preclean() || | |
4551 ConcurrentMarkSweepThread::should_terminate())) { | |
4552 workdone = preclean_work(CMSPrecleanRefLists2, CMSPrecleanSurvivors2); | |
4553 cumworkdone += workdone; | |
4554 loops++; | |
4555 // Voluntarily terminate abortable preclean phase if we have | |
4556 // been at it for too long. | |
4557 if ((CMSMaxAbortablePrecleanLoops != 0) && | |
4558 loops >= CMSMaxAbortablePrecleanLoops) { | |
4559 if (PrintGCDetails) { | |
4560 gclog_or_tty->print(" CMS: abort preclean due to loops "); | |
4561 } | |
4562 break; | |
4563 } | |
4564 if (pa.wallclock_millis() > CMSMaxAbortablePrecleanTime) { | |
4565 if (PrintGCDetails) { | |
4566 gclog_or_tty->print(" CMS: abort preclean due to time "); | |
4567 } | |
4568 break; | |
4569 } | |
4570 // If we are doing little work each iteration, we should | |
4571 // take a short break. | |
4572 if (workdone < CMSAbortablePrecleanMinWorkPerIteration) { | |
4573 // Sleep for some time, waiting for work to accumulate | |
4574 stopTimer(); | |
4575 cmsThread()->wait_on_cms_lock(CMSAbortablePrecleanWaitMillis); | |
4576 startTimer(); | |
4577 waited++; | |
4578 } | |
4579 } | |
4580 if (PrintCMSStatistics > 0) { | |
4581 gclog_or_tty->print(" [%d iterations, %d waits, %d cards)] ", | |
4582 loops, waited, cumworkdone); | |
4583 } | |
4584 } | |
4585 CMSTokenSync x(true); // is cms thread | |
4586 if (_collectorState != Idling) { | |
4587 assert(_collectorState == AbortablePreclean, | |
4588 "Spontaneous state transition?"); | |
4589 _collectorState = FinalMarking; | |
4590 } // Else, a foreground collection completed this CMS cycle. | |
4591 return; | |
4592 } | |
4593 | |
4594 // Respond to an Eden sampling opportunity | |
4595 void CMSCollector::sample_eden() { | |
4596 // Make sure a young gc cannot sneak in between our | |
4597 // reading and recording of a sample. | |
4598 assert(Thread::current()->is_ConcurrentGC_thread(), | |
4599 "Only the cms thread may collect Eden samples"); | |
4600 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
4601 "Should collect samples while holding CMS token"); | |
4602 if (!_start_sampling) { | |
4603 return; | |
4604 } | |
11973
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
4605 // When CMSEdenChunksRecordAlways is true, the eden chunk array |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
4606 // is populated by the young generation. |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
4607 if (_eden_chunk_array != NULL && !CMSEdenChunksRecordAlways) { |
0 | 4608 if (_eden_chunk_index < _eden_chunk_capacity) { |
4609 _eden_chunk_array[_eden_chunk_index] = *_top_addr; // take sample | |
4610 assert(_eden_chunk_array[_eden_chunk_index] <= *_end_addr, | |
4611 "Unexpected state of Eden"); | |
4612 // We'd like to check that what we just sampled is an oop-start address; | |
4613 // however, we cannot do that here since the object may not yet have been | |
4614 // initialized. So we'll instead do the check when we _use_ this sample | |
4615 // later. | |
4616 if (_eden_chunk_index == 0 || | |
4617 (pointer_delta(_eden_chunk_array[_eden_chunk_index], | |
4618 _eden_chunk_array[_eden_chunk_index-1]) | |
4619 >= CMSSamplingGrain)) { | |
4620 _eden_chunk_index++; // commit sample | |
4621 } | |
4622 } | |
4623 } | |
4624 if ((_collectorState == AbortablePreclean) && !_abort_preclean) { | |
4625 size_t used = get_eden_used(); | |
4626 size_t capacity = get_eden_capacity(); | |
4627 assert(used <= capacity, "Unexpected state of Eden"); | |
4628 if (used > (capacity/100 * CMSScheduleRemarkEdenPenetration)) { | |
4629 _abort_preclean = true; | |
4630 } | |
4631 } | |
4632 } | |
4633 | |
4634 | |
4635 size_t CMSCollector::preclean_work(bool clean_refs, bool clean_survivor) { | |
4636 assert(_collectorState == Precleaning || | |
4637 _collectorState == AbortablePreclean, "incorrect state"); | |
4638 ResourceMark rm; | |
4639 HandleMark hm; | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
4640 |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
4641 // Precleaning is currently not MT but the reference processor |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
4642 // may be set for MT. Disable it temporarily here. |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
4643 ReferenceProcessor* rp = ref_processor(); |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
4644 ReferenceProcessorMTDiscoveryMutator rp_mut_discovery(rp, false); |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
4645 |
0 | 4646 // Do one pass of scrubbing the discovered reference lists |
4647 // to remove any reference objects with strongly-reachable | |
4648 // referents. | |
4649 if (clean_refs) { | |
4650 CMSPrecleanRefsYieldClosure yield_cl(this); | |
4651 assert(rp->span().equals(_span), "Spans should be equal"); | |
4652 CMSKeepAliveClosure keep_alive(this, _span, &_markBitMap, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4653 &_markStack, true /* preclean */); |
0 | 4654 CMSDrainMarkingStackClosure complete_trace(this, |
452
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
4655 _span, &_markBitMap, &_markStack, |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
4656 &keep_alive, true /* preclean */); |
0 | 4657 |
4658 // We don't want this step to interfere with a young | |
4659 // collection because we don't want to take CPU | |
4660 // or memory bandwidth away from the young GC threads | |
4661 // (which may be as many as there are CPUs). | |
4662 // Note that we don't need to protect ourselves from | |
4663 // interference with mutators because they can't | |
4664 // manipulate the discovered reference lists nor affect | |
4665 // the computed reachability of the referents, the | |
4666 // only properties manipulated by the precleaning | |
4667 // of these reference lists. | |
4668 stopTimer(); | |
4669 CMSTokenSyncWithLocks x(true /* is cms thread */, | |
4670 bitMapLock()); | |
4671 startTimer(); | |
4672 sample_eden(); | |
935 | 4673 |
0 | 4674 // The following will yield to allow foreground |
4675 // collection to proceed promptly. XXX YSR: | |
4676 // The code in this method may need further | |
4677 // tweaking for better performance and some restructuring | |
4678 // for cleaner interfaces. | |
10405 | 4679 GCTimer *gc_timer = NULL; // Currently not tracing concurrent phases |
0 | 4680 rp->preclean_discovered_references( |
10405 | 4681 rp->is_alive_non_header(), &keep_alive, &complete_trace, &yield_cl, |
4682 gc_timer); | |
0 | 4683 } |
4684 | |
4685 if (clean_survivor) { // preclean the active survivor space(s) | |
4686 assert(_young_gen->kind() == Generation::DefNew || | |
4687 _young_gen->kind() == Generation::ParNew || | |
4688 _young_gen->kind() == Generation::ASParNew, | |
4689 "incorrect type for cast"); | |
4690 DefNewGeneration* dng = (DefNewGeneration*)_young_gen; | |
4691 PushAndMarkClosure pam_cl(this, _span, ref_processor(), | |
4692 &_markBitMap, &_modUnionTable, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4693 &_markStack, true /* precleaning phase */); |
0 | 4694 stopTimer(); |
4695 CMSTokenSyncWithLocks ts(true /* is cms thread */, | |
4696 bitMapLock()); | |
4697 startTimer(); | |
4698 unsigned int before_count = | |
4699 GenCollectedHeap::heap()->total_collections(); | |
4700 SurvivorSpacePrecleanClosure | |
4701 sss_cl(this, _span, &_markBitMap, &_markStack, | |
4702 &pam_cl, before_count, CMSYield); | |
4703 dng->from()->object_iterate_careful(&sss_cl); | |
4704 dng->to()->object_iterate_careful(&sss_cl); | |
4705 } | |
4706 MarkRefsIntoAndScanClosure | |
4707 mrias_cl(_span, ref_processor(), &_markBitMap, &_modUnionTable, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4708 &_markStack, this, CMSYield, |
0 | 4709 true /* precleaning phase */); |
4710 // CAUTION: The following closure has persistent state that may need to | |
4711 // be reset upon a decrease in the sequence of addresses it | |
4712 // processes. | |
4713 ScanMarkedObjectsAgainCarefullyClosure | |
4714 smoac_cl(this, _span, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4715 &_markBitMap, &_markStack, &mrias_cl, CMSYield); |
0 | 4716 |
4717 // Preclean dirty cards in ModUnionTable and CardTable using | |
4718 // appropriate convergence criterion; | |
4719 // repeat CMSPrecleanIter times unless we find that | |
4720 // we are losing. | |
4721 assert(CMSPrecleanIter < 10, "CMSPrecleanIter is too large"); | |
4722 assert(CMSPrecleanNumerator < CMSPrecleanDenominator, | |
4723 "Bad convergence multiplier"); | |
4724 assert(CMSPrecleanThreshold >= 100, | |
4725 "Unreasonably low CMSPrecleanThreshold"); | |
4726 | |
4727 size_t numIter, cumNumCards, lastNumCards, curNumCards; | |
4728 for (numIter = 0, cumNumCards = lastNumCards = curNumCards = 0; | |
4729 numIter < CMSPrecleanIter; | |
4730 numIter++, lastNumCards = curNumCards, cumNumCards += curNumCards) { | |
4731 curNumCards = preclean_mod_union_table(_cmsGen, &smoac_cl); | |
4732 if (Verbose && PrintGCDetails) { | |
4733 gclog_or_tty->print(" (modUnionTable: %d cards)", curNumCards); | |
4734 } | |
4735 // Either there are very few dirty cards, so re-mark | |
4736 // pause will be small anyway, or our pre-cleaning isn't | |
4737 // that much faster than the rate at which cards are being | |
4738 // dirtied, so we might as well stop and re-mark since | |
4739 // precleaning won't improve our re-mark time by much. | |
4740 if (curNumCards <= CMSPrecleanThreshold || | |
4741 (numIter > 0 && | |
4742 (curNumCards * CMSPrecleanDenominator > | |
4743 lastNumCards * CMSPrecleanNumerator))) { | |
4744 numIter++; | |
4745 cumNumCards += curNumCards; | |
4746 break; | |
4747 } | |
4748 } | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4749 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4750 preclean_klasses(&mrias_cl, _cmsGen->freelistLock()); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4751 |
0 | 4752 curNumCards = preclean_card_table(_cmsGen, &smoac_cl); |
4753 cumNumCards += curNumCards; | |
4754 if (PrintGCDetails && PrintCMSStatistics != 0) { | |
4755 gclog_or_tty->print_cr(" (cardTable: %d cards, re-scanned %d cards, %d iterations)", | |
4756 curNumCards, cumNumCards, numIter); | |
4757 } | |
4758 return cumNumCards; // as a measure of useful work done | |
4759 } | |
4760 | |
4761 // PRECLEANING NOTES: | |
4762 // Precleaning involves: | |
4763 // . reading the bits of the modUnionTable and clearing the set bits. | |
4764 // . For the cards corresponding to the set bits, we scan the | |
4765 // objects on those cards. This means we need the free_list_lock | |
4766 // so that we can safely iterate over the CMS space when scanning | |
4767 // for oops. | |
4768 // . When we scan the objects, we'll be both reading and setting | |
4769 // marks in the marking bit map, so we'll need the marking bit map. | |
4770 // . For protecting _collector_state transitions, we take the CGC_lock. | |
4771 // Note that any races in the reading of of card table entries by the | |
4772 // CMS thread on the one hand and the clearing of those entries by the | |
4773 // VM thread or the setting of those entries by the mutator threads on the | |
4774 // other are quite benign. However, for efficiency it makes sense to keep | |
4775 // the VM thread from racing with the CMS thread while the latter is | |
4776 // dirty card info to the modUnionTable. We therefore also use the | |
4777 // CGC_lock to protect the reading of the card table and the mod union | |
4778 // table by the CM thread. | |
4779 // . We run concurrently with mutator updates, so scanning | |
4780 // needs to be done carefully -- we should not try to scan | |
4781 // potentially uninitialized objects. | |
4782 // | |
4783 // Locking strategy: While holding the CGC_lock, we scan over and | |
4784 // reset a maximal dirty range of the mod union / card tables, then lock | |
4785 // the free_list_lock and bitmap lock to do a full marking, then | |
4786 // release these locks; and repeat the cycle. This allows for a | |
4787 // certain amount of fairness in the sharing of these locks between | |
4788 // the CMS collector on the one hand, and the VM thread and the | |
4789 // mutators on the other. | |
4790 | |
4791 // NOTE: preclean_mod_union_table() and preclean_card_table() | |
4792 // further below are largely identical; if you need to modify | |
4793 // one of these methods, please check the other method too. | |
4794 | |
4795 size_t CMSCollector::preclean_mod_union_table( | |
4796 ConcurrentMarkSweepGeneration* gen, | |
4797 ScanMarkedObjectsAgainCarefullyClosure* cl) { | |
4798 verify_work_stacks_empty(); | |
4799 verify_overflow_empty(); | |
4800 | |
4801 // strategy: starting with the first card, accumulate contiguous | |
4802 // ranges of dirty cards; clear these cards, then scan the region | |
4803 // covered by these cards. | |
4804 | |
4805 // Since all of the MUT is committed ahead, we can just use | |
4806 // that, in case the generations expand while we are precleaning. | |
4807 // It might also be fine to just use the committed part of the | |
4808 // generation, but we might potentially miss cards when the | |
4809 // generation is rapidly expanding while we are in the midst | |
4810 // of precleaning. | |
4811 HeapWord* startAddr = gen->reserved().start(); | |
4812 HeapWord* endAddr = gen->reserved().end(); | |
4813 | |
4814 cl->setFreelistLock(gen->freelistLock()); // needed for yielding | |
4815 | |
4816 size_t numDirtyCards, cumNumDirtyCards; | |
4817 HeapWord *nextAddr, *lastAddr; | |
4818 for (cumNumDirtyCards = numDirtyCards = 0, | |
4819 nextAddr = lastAddr = startAddr; | |
4820 nextAddr < endAddr; | |
4821 nextAddr = lastAddr, cumNumDirtyCards += numDirtyCards) { | |
4822 | |
4823 ResourceMark rm; | |
4824 HandleMark hm; | |
4825 | |
4826 MemRegion dirtyRegion; | |
4827 { | |
4828 stopTimer(); | |
935 | 4829 // Potential yield point |
0 | 4830 CMSTokenSync ts(true); |
4831 startTimer(); | |
4832 sample_eden(); | |
4833 // Get dirty region starting at nextOffset (inclusive), | |
4834 // simultaneously clearing it. | |
4835 dirtyRegion = | |
4836 _modUnionTable.getAndClearMarkedRegion(nextAddr, endAddr); | |
4837 assert(dirtyRegion.start() >= nextAddr, | |
4838 "returned region inconsistent?"); | |
4839 } | |
4840 // Remember where the next search should begin. | |
4841 // The returned region (if non-empty) is a right open interval, | |
4842 // so lastOffset is obtained from the right end of that | |
4843 // interval. | |
4844 lastAddr = dirtyRegion.end(); | |
4845 // Should do something more transparent and less hacky XXX | |
4846 numDirtyCards = | |
4847 _modUnionTable.heapWordDiffToOffsetDiff(dirtyRegion.word_size()); | |
4848 | |
4849 // We'll scan the cards in the dirty region (with periodic | |
4850 // yields for foreground GC as needed). | |
4851 if (!dirtyRegion.is_empty()) { | |
4852 assert(numDirtyCards > 0, "consistency check"); | |
4853 HeapWord* stop_point = NULL; | |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
4854 stopTimer(); |
935 | 4855 // Potential yield point |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
4856 CMSTokenSyncWithLocks ts(true, gen->freelistLock(), |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
4857 bitMapLock()); |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
4858 startTimer(); |
0 | 4859 { |
4860 verify_work_stacks_empty(); | |
4861 verify_overflow_empty(); | |
4862 sample_eden(); | |
4863 stop_point = | |
4864 gen->cmsSpace()->object_iterate_careful_m(dirtyRegion, cl); | |
4865 } | |
4866 if (stop_point != NULL) { | |
4867 // The careful iteration stopped early either because it found an | |
4868 // uninitialized object, or because we were in the midst of an | |
4869 // "abortable preclean", which should now be aborted. Redirty | |
4870 // the bits corresponding to the partially-scanned or unscanned | |
4871 // cards. We'll either restart at the next block boundary or | |
4872 // abort the preclean. | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4873 assert((_collectorState == AbortablePreclean && should_abort_preclean()), |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4874 "Should only be AbortablePreclean."); |
0 | 4875 _modUnionTable.mark_range(MemRegion(stop_point, dirtyRegion.end())); |
4876 if (should_abort_preclean()) { | |
4877 break; // out of preclean loop | |
4878 } else { | |
4879 // Compute the next address at which preclean should pick up; | |
4880 // might need bitMapLock in order to read P-bits. | |
4881 lastAddr = next_card_start_after_block(stop_point); | |
4882 } | |
4883 } | |
4884 } else { | |
4885 assert(lastAddr == endAddr, "consistency check"); | |
4886 assert(numDirtyCards == 0, "consistency check"); | |
4887 break; | |
4888 } | |
4889 } | |
4890 verify_work_stacks_empty(); | |
4891 verify_overflow_empty(); | |
4892 return cumNumDirtyCards; | |
4893 } | |
4894 | |
4895 // NOTE: preclean_mod_union_table() above and preclean_card_table() | |
4896 // below are largely identical; if you need to modify | |
4897 // one of these methods, please check the other method too. | |
4898 | |
4899 size_t CMSCollector::preclean_card_table(ConcurrentMarkSweepGeneration* gen, | |
4900 ScanMarkedObjectsAgainCarefullyClosure* cl) { | |
4901 // strategy: it's similar to precleamModUnionTable above, in that | |
4902 // we accumulate contiguous ranges of dirty cards, mark these cards | |
4903 // precleaned, then scan the region covered by these cards. | |
4904 HeapWord* endAddr = (HeapWord*)(gen->_virtual_space.high()); | |
4905 HeapWord* startAddr = (HeapWord*)(gen->_virtual_space.low()); | |
4906 | |
4907 cl->setFreelistLock(gen->freelistLock()); // needed for yielding | |
4908 | |
4909 size_t numDirtyCards, cumNumDirtyCards; | |
4910 HeapWord *lastAddr, *nextAddr; | |
4911 | |
4912 for (cumNumDirtyCards = numDirtyCards = 0, | |
4913 nextAddr = lastAddr = startAddr; | |
4914 nextAddr < endAddr; | |
4915 nextAddr = lastAddr, cumNumDirtyCards += numDirtyCards) { | |
4916 | |
4917 ResourceMark rm; | |
4918 HandleMark hm; | |
4919 | |
4920 MemRegion dirtyRegion; | |
4921 { | |
4922 // See comments in "Precleaning notes" above on why we | |
4923 // do this locking. XXX Could the locking overheads be | |
4924 // too high when dirty cards are sparse? [I don't think so.] | |
4925 stopTimer(); | |
4926 CMSTokenSync x(true); // is cms thread | |
4927 startTimer(); | |
4928 sample_eden(); | |
4929 // Get and clear dirty region from card table | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
4930 dirtyRegion = _ct->ct_bs()->dirty_card_range_after_reset( |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
4931 MemRegion(nextAddr, endAddr), |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
4932 true, |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
4933 CardTableModRefBS::precleaned_card_val()); |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
4934 |
0 | 4935 assert(dirtyRegion.start() >= nextAddr, |
4936 "returned region inconsistent?"); | |
4937 } | |
4938 lastAddr = dirtyRegion.end(); | |
4939 numDirtyCards = | |
4940 dirtyRegion.word_size()/CardTableModRefBS::card_size_in_words; | |
4941 | |
4942 if (!dirtyRegion.is_empty()) { | |
4943 stopTimer(); | |
4944 CMSTokenSyncWithLocks ts(true, gen->freelistLock(), bitMapLock()); | |
4945 startTimer(); | |
4946 sample_eden(); | |
4947 verify_work_stacks_empty(); | |
4948 verify_overflow_empty(); | |
4949 HeapWord* stop_point = | |
4950 gen->cmsSpace()->object_iterate_careful_m(dirtyRegion, cl); | |
4951 if (stop_point != NULL) { | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4952 assert((_collectorState == AbortablePreclean && should_abort_preclean()), |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4953 "Should only be AbortablePreclean."); |
0 | 4954 _ct->ct_bs()->invalidate(MemRegion(stop_point, dirtyRegion.end())); |
4955 if (should_abort_preclean()) { | |
4956 break; // out of preclean loop | |
4957 } else { | |
4958 // Compute the next address at which preclean should pick up. | |
4959 lastAddr = next_card_start_after_block(stop_point); | |
4960 } | |
4961 } | |
4962 } else { | |
4963 break; | |
4964 } | |
4965 } | |
4966 verify_work_stacks_empty(); | |
4967 verify_overflow_empty(); | |
4968 return cumNumDirtyCards; | |
4969 } | |
4970 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4971 class PrecleanKlassClosure : public KlassClosure { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4972 CMKlassClosure _cm_klass_closure; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4973 public: |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4974 PrecleanKlassClosure(OopClosure* oop_closure) : _cm_klass_closure(oop_closure) {} |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4975 void do_klass(Klass* k) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4976 if (k->has_accumulated_modified_oops()) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4977 k->clear_accumulated_modified_oops(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4978 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4979 _cm_klass_closure.do_klass(k); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4980 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4981 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4982 }; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4983 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4984 // The freelist lock is needed to prevent asserts, is it really needed? |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4985 void CMSCollector::preclean_klasses(MarkRefsIntoAndScanClosure* cl, Mutex* freelistLock) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4986 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4987 cl->set_freelistLock(freelistLock); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4988 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4989 CMSTokenSyncWithLocks ts(true, freelistLock, bitMapLock()); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4990 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4991 // SSS: Add equivalent to ScanMarkedObjectsAgainCarefullyClosure::do_yield_check and should_abort_preclean? |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4992 // SSS: We should probably check if precleaning should be aborted, at suitable intervals? |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4993 PrecleanKlassClosure preclean_klass_closure(cl); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4994 ClassLoaderDataGraph::classes_do(&preclean_klass_closure); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4995 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4996 verify_work_stacks_empty(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4997 verify_overflow_empty(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4998 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
4999 |
0 | 5000 void CMSCollector::checkpointRootsFinal(bool asynch, |
5001 bool clear_all_soft_refs, bool init_mark_was_synchronous) { | |
5002 assert(_collectorState == FinalMarking, "incorrect state transition?"); | |
5003 check_correct_thread_executing(); | |
5004 // world is stopped at this checkpoint | |
5005 assert(SafepointSynchronize::is_at_safepoint(), | |
5006 "world should be stopped"); | |
3356
78542e2b5e35
7036199: Adding a notification to the implementation of GarbageCollectorMXBeans
fparain
parents:
3293
diff
changeset
|
5007 TraceCMSMemoryManagerStats tms(_collectorState,GenCollectedHeap::heap()->gc_cause()); |
78542e2b5e35
7036199: Adding a notification to the implementation of GarbageCollectorMXBeans
fparain
parents:
3293
diff
changeset
|
5008 |
0 | 5009 verify_work_stacks_empty(); |
5010 verify_overflow_empty(); | |
5011 | |
5012 SpecializationStats::clear(); | |
5013 if (PrintGCDetails) { | |
5014 gclog_or_tty->print("[YG occupancy: "SIZE_FORMAT" K ("SIZE_FORMAT" K)]", | |
5015 _young_gen->used() / K, | |
5016 _young_gen->capacity() / K); | |
5017 } | |
5018 if (asynch) { | |
5019 if (CMSScavengeBeforeRemark) { | |
5020 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
5021 // Temporarily set flag to false, GCH->do_collection will | |
5022 // expect it to be false and set to true | |
5023 FlagSetting fl(gch->_is_gc_active, false); | |
10405 | 5024 NOT_PRODUCT(GCTraceTime t("Scavenge-Before-Remark", |
5025 PrintGCDetails && Verbose, true, _gc_timer_cm);) | |
0 | 5026 int level = _cmsGen->level() - 1; |
5027 if (level >= 0) { | |
5028 gch->do_collection(true, // full (i.e. force, see below) | |
5029 false, // !clear_all_soft_refs | |
5030 0, // size | |
5031 false, // is_tlab | |
5032 level // max_level | |
5033 ); | |
5034 } | |
5035 } | |
5036 FreelistLocker x(this); | |
5037 MutexLockerEx y(bitMapLock(), | |
5038 Mutex::_no_safepoint_check_flag); | |
5039 assert(!init_mark_was_synchronous, "but that's impossible!"); | |
5040 checkpointRootsFinalWork(asynch, clear_all_soft_refs, false); | |
5041 } else { | |
5042 // already have all the locks | |
5043 checkpointRootsFinalWork(asynch, clear_all_soft_refs, | |
5044 init_mark_was_synchronous); | |
5045 } | |
5046 verify_work_stacks_empty(); | |
5047 verify_overflow_empty(); | |
5048 SpecializationStats::print(); | |
5049 } | |
5050 | |
5051 void CMSCollector::checkpointRootsFinalWork(bool asynch, | |
5052 bool clear_all_soft_refs, bool init_mark_was_synchronous) { | |
5053 | |
10405 | 5054 NOT_PRODUCT(GCTraceTime tr("checkpointRootsFinalWork", PrintGCDetails, false, _gc_timer_cm);) |
0 | 5055 |
5056 assert(haveFreelistLocks(), "must have free list locks"); | |
5057 assert_lock_strong(bitMapLock()); | |
5058 | |
5059 if (UseAdaptiveSizePolicy) { | |
5060 size_policy()->checkpoint_roots_final_begin(); | |
5061 } | |
5062 | |
5063 ResourceMark rm; | |
5064 HandleMark hm; | |
5065 | |
5066 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
5067 | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
5068 if (should_unload_classes()) { |
0 | 5069 CodeCache::gc_prologue(); |
5070 } | |
5071 assert(haveFreelistLocks(), "must have free list locks"); | |
5072 assert_lock_strong(bitMapLock()); | |
5073 | |
5074 if (!init_mark_was_synchronous) { | |
5075 // We might assume that we need not fill TLAB's when | |
5076 // CMSScavengeBeforeRemark is set, because we may have just done | |
5077 // a scavenge which would have filled all TLAB's -- and besides | |
5078 // Eden would be empty. This however may not always be the case -- | |
5079 // for instance although we asked for a scavenge, it may not have | |
5080 // happened because of a JNI critical section. We probably need | |
5081 // a policy for deciding whether we can in that case wait until | |
5082 // the critical section releases and then do the remark following | |
5083 // the scavenge, and skip it here. In the absence of that policy, | |
5084 // or of an indication of whether the scavenge did indeed occur, | |
5085 // we cannot rely on TLAB's having been filled and must do | |
5086 // so here just in case a scavenge did not happen. | |
5087 gch->ensure_parsability(false); // fill TLAB's, but no need to retire them | |
5088 // Update the saved marks which may affect the root scans. | |
5089 gch->save_marks(); | |
5090 | |
11973
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5091 if (CMSPrintEdenSurvivorChunks) { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5092 print_eden_and_survivor_chunk_arrays(); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5093 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5094 |
0 | 5095 { |
5096 COMPILER2_PRESENT(DerivedPointerTableDeactivate dpt_deact;) | |
5097 | |
5098 // Note on the role of the mod union table: | |
5099 // Since the marker in "markFromRoots" marks concurrently with | |
5100 // mutators, it is possible for some reachable objects not to have been | |
5101 // scanned. For instance, an only reference to an object A was | |
5102 // placed in object B after the marker scanned B. Unless B is rescanned, | |
5103 // A would be collected. Such updates to references in marked objects | |
5104 // are detected via the mod union table which is the set of all cards | |
5105 // dirtied since the first checkpoint in this GC cycle and prior to | |
5106 // the most recent young generation GC, minus those cleaned up by the | |
5107 // concurrent precleaning. | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5108 if (CMSParallelRemarkEnabled && CollectedHeap::use_parallel_gc_threads()) { |
10405 | 5109 GCTraceTime t("Rescan (parallel) ", PrintGCDetails, false, _gc_timer_cm); |
0 | 5110 do_remark_parallel(); |
5111 } else { | |
10405 | 5112 GCTraceTime t("Rescan (non-parallel) ", PrintGCDetails, false, |
5113 _gc_timer_cm); | |
0 | 5114 do_remark_non_parallel(); |
5115 } | |
5116 } | |
5117 } else { | |
5118 assert(!asynch, "Can't have init_mark_was_synchronous in asynch mode"); | |
5119 // The initial mark was stop-world, so there's no rescanning to | |
5120 // do; go straight on to the next step below. | |
5121 } | |
5122 verify_work_stacks_empty(); | |
5123 verify_overflow_empty(); | |
5124 | |
5125 { | |
10405 | 5126 NOT_PRODUCT(GCTraceTime ts("refProcessingWork", PrintGCDetails, false, _gc_timer_cm);) |
0 | 5127 refProcessingWork(asynch, clear_all_soft_refs); |
5128 } | |
5129 verify_work_stacks_empty(); | |
5130 verify_overflow_empty(); | |
5131 | |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
5132 if (should_unload_classes()) { |
0 | 5133 CodeCache::gc_epilogue(); |
5134 } | |
2147
9afee0b9fc1d
7012505: BreakpointWithFullGC.sh fails with Internal Error (src/share/vm/oops/methodOop.cpp:220)
kamg
parents:
2137
diff
changeset
|
5135 JvmtiExport::gc_epilogue(); |
0 | 5136 |
5137 // If we encountered any (marking stack / work queue) overflow | |
5138 // events during the current CMS cycle, take appropriate | |
5139 // remedial measures, where possible, so as to try and avoid | |
5140 // recurrence of that condition. | |
5141 assert(_markStack.isEmpty(), "No grey objects"); | |
5142 size_t ser_ovflw = _ser_pmc_remark_ovflw + _ser_pmc_preclean_ovflw + | |
452
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
5143 _ser_kac_ovflw + _ser_kac_preclean_ovflw; |
0 | 5144 if (ser_ovflw > 0) { |
5145 if (PrintCMSStatistics != 0) { | |
5146 gclog_or_tty->print_cr("Marking stack overflow (benign) " | |
452
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
5147 "(pmc_pc="SIZE_FORMAT", pmc_rm="SIZE_FORMAT", kac="SIZE_FORMAT |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
5148 ", kac_preclean="SIZE_FORMAT")", |
0 | 5149 _ser_pmc_preclean_ovflw, _ser_pmc_remark_ovflw, |
452
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
5150 _ser_kac_ovflw, _ser_kac_preclean_ovflw); |
0 | 5151 } |
5152 _markStack.expand(); | |
5153 _ser_pmc_remark_ovflw = 0; | |
5154 _ser_pmc_preclean_ovflw = 0; | |
452
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
5155 _ser_kac_preclean_ovflw = 0; |
0 | 5156 _ser_kac_ovflw = 0; |
5157 } | |
5158 if (_par_pmc_remark_ovflw > 0 || _par_kac_ovflw > 0) { | |
5159 if (PrintCMSStatistics != 0) { | |
5160 gclog_or_tty->print_cr("Work queue overflow (benign) " | |
5161 "(pmc_rm="SIZE_FORMAT", kac="SIZE_FORMAT")", | |
5162 _par_pmc_remark_ovflw, _par_kac_ovflw); | |
5163 } | |
5164 _par_pmc_remark_ovflw = 0; | |
5165 _par_kac_ovflw = 0; | |
5166 } | |
5167 if (PrintCMSStatistics != 0) { | |
5168 if (_markStack._hit_limit > 0) { | |
5169 gclog_or_tty->print_cr(" (benign) Hit max stack size limit ("SIZE_FORMAT")", | |
5170 _markStack._hit_limit); | |
5171 } | |
5172 if (_markStack._failed_double > 0) { | |
5173 gclog_or_tty->print_cr(" (benign) Failed stack doubling ("SIZE_FORMAT")," | |
5174 " current capacity "SIZE_FORMAT, | |
5175 _markStack._failed_double, | |
5176 _markStack.capacity()); | |
5177 } | |
5178 } | |
5179 _markStack._hit_limit = 0; | |
5180 _markStack._failed_double = 0; | |
5181 | |
5182 if ((VerifyAfterGC || VerifyDuringGC) && | |
5183 GenCollectedHeap::heap()->total_collections() >= VerifyGCStartAt) { | |
5184 verify_after_remark(); | |
5185 } | |
5186 | |
10405 | 5187 _gc_tracer_cm->report_object_count_after_gc(&_is_alive_closure); |
5188 | |
0 | 5189 // Change under the freelistLocks. |
5190 _collectorState = Sweeping; | |
5191 // Call isAllClear() under bitMapLock | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5192 assert(_modUnionTable.isAllClear(), |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5193 "Should be clear by end of the final marking"); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5194 assert(_ct->klass_rem_set()->mod_union_is_clear(), |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5195 "Should be clear by end of the final marking"); |
0 | 5196 if (UseAdaptiveSizePolicy) { |
5197 size_policy()->checkpoint_roots_final_end(gch->gc_cause()); | |
5198 } | |
5199 } | |
5200 | |
11975 | 5201 void CMSParInitialMarkTask::work(uint worker_id) { |
5202 elapsedTimer _timer; | |
5203 ResourceMark rm; | |
5204 HandleMark hm; | |
5205 | |
5206 // ---------- scan from roots -------------- | |
5207 _timer.start(); | |
5208 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
5209 Par_MarkRefsIntoClosure par_mri_cl(_collector->_span, &(_collector->_markBitMap)); | |
5210 CMKlassClosure klass_closure(&par_mri_cl); | |
5211 | |
5212 // ---------- young gen roots -------------- | |
5213 { | |
5214 work_on_young_gen_roots(worker_id, &par_mri_cl); | |
5215 _timer.stop(); | |
5216 if (PrintCMSStatistics != 0) { | |
5217 gclog_or_tty->print_cr( | |
5218 "Finished young gen initial mark scan work in %dth thread: %3.3f sec", | |
5219 worker_id, _timer.seconds()); | |
5220 } | |
5221 } | |
5222 | |
5223 // ---------- remaining roots -------------- | |
5224 _timer.reset(); | |
5225 _timer.start(); | |
5226 gch->gen_process_strong_roots(_collector->_cmsGen->level(), | |
5227 false, // yg was scanned above | |
5228 false, // this is parallel code | |
5229 SharedHeap::ScanningOption(_collector->CMSCollector::roots_scanning_options()), | |
5230 &par_mri_cl, | |
5231 NULL, | |
5232 &klass_closure); | |
5233 assert(_collector->should_unload_classes() | |
14308
870aedf4ba4f
8032379: Remove the is_scavenging flag to process_strong_roots
mgerdin
parents:
13400
diff
changeset
|
5234 || (_collector->CMSCollector::roots_scanning_options() & SharedHeap::SO_AllCodeCache), |
11975 | 5235 "if we didn't scan the code cache, we have to be ready to drop nmethods with expired weak oops"); |
5236 _timer.stop(); | |
5237 if (PrintCMSStatistics != 0) { | |
5238 gclog_or_tty->print_cr( | |
5239 "Finished remaining root initial mark scan work in %dth thread: %3.3f sec", | |
5240 worker_id, _timer.seconds()); | |
5241 } | |
5242 } | |
5243 | |
0 | 5244 // Parallel remark task |
11975 | 5245 class CMSParRemarkTask: public CMSParMarkTask { |
0 | 5246 CompactibleFreeListSpace* _cms_space; |
5247 | |
5248 // The per-thread work queues, available here for stealing. | |
5249 OopTaskQueueSet* _task_queues; | |
5250 ParallelTaskTerminator _term; | |
5251 | |
5252 public: | |
4095
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5253 // A value of 0 passed to n_workers will cause the number of |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5254 // workers to be taken from the active workers in the work gang. |
0 | 5255 CMSParRemarkTask(CMSCollector* collector, |
5256 CompactibleFreeListSpace* cms_space, | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5257 int n_workers, FlexibleWorkGang* workers, |
0 | 5258 OopTaskQueueSet* task_queues): |
11975 | 5259 CMSParMarkTask("Rescan roots and grey objects in parallel", |
5260 collector, n_workers), | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5261 _cms_space(cms_space), |
0 | 5262 _task_queues(task_queues), |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5263 _term(n_workers, task_queues) { } |
0 | 5264 |
5265 OopTaskQueueSet* task_queues() { return _task_queues; } | |
5266 | |
5267 OopTaskQueue* work_queue(int i) { return task_queues()->queue(i); } | |
5268 | |
5269 ParallelTaskTerminator* terminator() { return &_term; } | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5270 int n_workers() { return _n_workers; } |
0 | 5271 |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5272 void work(uint worker_id); |
0 | 5273 |
5274 private: | |
5275 // ... of dirty cards in old space | |
5276 void do_dirty_card_rescan_tasks(CompactibleFreeListSpace* sp, int i, | |
5277 Par_MarkRefsIntoAndScanClosure* cl); | |
5278 | |
5279 // ... work stealing for the above | |
5280 void do_work_steal(int i, Par_MarkRefsIntoAndScanClosure* cl, int* seed); | |
5281 }; | |
5282 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5283 class RemarkKlassClosure : public KlassClosure { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5284 CMKlassClosure _cm_klass_closure; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5285 public: |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5286 RemarkKlassClosure(OopClosure* oop_closure) : _cm_klass_closure(oop_closure) {} |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5287 void do_klass(Klass* k) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5288 // Check if we have modified any oops in the Klass during the concurrent marking. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5289 if (k->has_accumulated_modified_oops()) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5290 k->clear_accumulated_modified_oops(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5291 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5292 // We could have transfered the current modified marks to the accumulated marks, |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5293 // like we do with the Card Table to Mod Union Table. But it's not really necessary. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5294 } else if (k->has_modified_oops()) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5295 // Don't clear anything, this info is needed by the next young collection. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5296 } else { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5297 // No modified oops in the Klass. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5298 return; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5299 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5300 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5301 // The klass has modified fields, need to scan the klass. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5302 _cm_klass_closure.do_klass(k); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5303 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5304 }; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5305 |
11975 | 5306 void CMSParMarkTask::work_on_young_gen_roots(uint worker_id, OopsInGenClosure* cl) { |
5307 DefNewGeneration* dng = _collector->_young_gen->as_DefNewGeneration(); | |
5308 EdenSpace* eden_space = dng->eden(); | |
5309 ContiguousSpace* from_space = dng->from(); | |
5310 ContiguousSpace* to_space = dng->to(); | |
5311 | |
5312 HeapWord** eca = _collector->_eden_chunk_array; | |
5313 size_t ect = _collector->_eden_chunk_index; | |
5314 HeapWord** sca = _collector->_survivor_chunk_array; | |
5315 size_t sct = _collector->_survivor_chunk_index; | |
5316 | |
5317 assert(ect <= _collector->_eden_chunk_capacity, "out of bounds"); | |
5318 assert(sct <= _collector->_survivor_chunk_capacity, "out of bounds"); | |
5319 | |
5320 do_young_space_rescan(worker_id, cl, to_space, NULL, 0); | |
5321 do_young_space_rescan(worker_id, cl, from_space, sca, sct); | |
5322 do_young_space_rescan(worker_id, cl, eden_space, eca, ect); | |
5323 } | |
5324 | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5325 // work_queue(i) is passed to the closure |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5326 // Par_MarkRefsIntoAndScanClosure. The "i" parameter |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5327 // also is passed to do_dirty_card_rescan_tasks() and to |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5328 // do_work_steal() to select the i-th task_queue. |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5329 |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5330 void CMSParRemarkTask::work(uint worker_id) { |
0 | 5331 elapsedTimer _timer; |
5332 ResourceMark rm; | |
5333 HandleMark hm; | |
5334 | |
5335 // ---------- rescan from roots -------------- | |
5336 _timer.start(); | |
5337 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
5338 Par_MarkRefsIntoAndScanClosure par_mrias_cl(_collector, | |
5339 _collector->_span, _collector->ref_processor(), | |
5340 &(_collector->_markBitMap), | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5341 work_queue(worker_id)); |
0 | 5342 |
5343 // Rescan young gen roots first since these are likely | |
5344 // coarsely partitioned and may, on that account, constitute | |
5345 // the critical path; thus, it's best to start off that | |
5346 // work first. | |
5347 // ---------- young gen roots -------------- | |
5348 { | |
11975 | 5349 work_on_young_gen_roots(worker_id, &par_mrias_cl); |
0 | 5350 _timer.stop(); |
5351 if (PrintCMSStatistics != 0) { | |
5352 gclog_or_tty->print_cr( | |
5353 "Finished young gen rescan work in %dth thread: %3.3f sec", | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5354 worker_id, _timer.seconds()); |
0 | 5355 } |
5356 } | |
5357 | |
5358 // ---------- remaining roots -------------- | |
5359 _timer.reset(); | |
5360 _timer.start(); | |
5361 gch->gen_process_strong_roots(_collector->_cmsGen->level(), | |
5362 false, // yg was scanned above | |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5363 false, // this is parallel code |
0 | 5364 SharedHeap::ScanningOption(_collector->CMSCollector::roots_scanning_options()), |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5365 &par_mrias_cl, |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5366 NULL, |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5367 NULL); // The dirty klasses will be handled below |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5368 assert(_collector->should_unload_classes() |
14308
870aedf4ba4f
8032379: Remove the is_scavenging flag to process_strong_roots
mgerdin
parents:
13400
diff
changeset
|
5369 || (_collector->CMSCollector::roots_scanning_options() & SharedHeap::SO_AllCodeCache), |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5370 "if we didn't scan the code cache, we have to be ready to drop nmethods with expired weak oops"); |
0 | 5371 _timer.stop(); |
5372 if (PrintCMSStatistics != 0) { | |
5373 gclog_or_tty->print_cr( | |
5374 "Finished remaining root rescan work in %dth thread: %3.3f sec", | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5375 worker_id, _timer.seconds()); |
0 | 5376 } |
5377 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5378 // ---------- unhandled CLD scanning ---------- |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5379 if (worker_id == 0) { // Single threaded at the moment. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5380 _timer.reset(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5381 _timer.start(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5382 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5383 // Scan all new class loader data objects and new dependencies that were |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5384 // introduced during concurrent marking. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5385 ResourceMark rm; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5386 GrowableArray<ClassLoaderData*>* array = ClassLoaderDataGraph::new_clds(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5387 for (int i = 0; i < array->length(); i++) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5388 par_mrias_cl.do_class_loader_data(array->at(i)); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5389 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5390 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5391 // We don't need to keep track of new CLDs anymore. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5392 ClassLoaderDataGraph::remember_new_clds(false); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5393 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5394 _timer.stop(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5395 if (PrintCMSStatistics != 0) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5396 gclog_or_tty->print_cr( |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5397 "Finished unhandled CLD scanning work in %dth thread: %3.3f sec", |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5398 worker_id, _timer.seconds()); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5399 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5400 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5401 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5402 // ---------- dirty klass scanning ---------- |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5403 if (worker_id == 0) { // Single threaded at the moment. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5404 _timer.reset(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5405 _timer.start(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5406 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5407 // Scan all classes that was dirtied during the concurrent marking phase. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5408 RemarkKlassClosure remark_klass_closure(&par_mrias_cl); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5409 ClassLoaderDataGraph::classes_do(&remark_klass_closure); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5410 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5411 _timer.stop(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5412 if (PrintCMSStatistics != 0) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5413 gclog_or_tty->print_cr( |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5414 "Finished dirty klass scanning work in %dth thread: %3.3f sec", |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5415 worker_id, _timer.seconds()); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5416 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5417 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5418 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5419 // We might have added oops to ClassLoaderData::_handles during the |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5420 // concurrent marking phase. These oops point to newly allocated objects |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5421 // that are guaranteed to be kept alive. Either by the direct allocation |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5422 // code, or when the young collector processes the strong roots. Hence, |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5423 // we don't have to revisit the _handles block during the remark phase. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5424 |
0 | 5425 // ---------- rescan dirty cards ------------ |
5426 _timer.reset(); | |
5427 _timer.start(); | |
5428 | |
5429 // Do the rescan tasks for each of the two spaces | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5430 // (cms_space) in turn. |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5431 // "worker_id" is passed to select the task_queue for "worker_id" |
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5432 do_dirty_card_rescan_tasks(_cms_space, worker_id, &par_mrias_cl); |
0 | 5433 _timer.stop(); |
5434 if (PrintCMSStatistics != 0) { | |
5435 gclog_or_tty->print_cr( | |
5436 "Finished dirty card rescan work in %dth thread: %3.3f sec", | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5437 worker_id, _timer.seconds()); |
0 | 5438 } |
5439 | |
5440 // ---------- steal work from other threads ... | |
5441 // ---------- ... and drain overflow list. | |
5442 _timer.reset(); | |
5443 _timer.start(); | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5444 do_work_steal(worker_id, &par_mrias_cl, _collector->hash_seed(worker_id)); |
0 | 5445 _timer.stop(); |
5446 if (PrintCMSStatistics != 0) { | |
5447 gclog_or_tty->print_cr( | |
5448 "Finished work stealing in %dth thread: %3.3f sec", | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5449 worker_id, _timer.seconds()); |
0 | 5450 } |
5451 } | |
5452 | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5453 // Note that parameter "i" is not used. |
0 | 5454 void |
11975 | 5455 CMSParMarkTask::do_young_space_rescan(uint worker_id, |
5456 OopsInGenClosure* cl, ContiguousSpace* space, | |
0 | 5457 HeapWord** chunk_array, size_t chunk_top) { |
5458 // Until all tasks completed: | |
5459 // . claim an unclaimed task | |
5460 // . compute region boundaries corresponding to task claimed | |
5461 // using chunk_array | |
5462 // . par_oop_iterate(cl) over that region | |
5463 | |
5464 ResourceMark rm; | |
5465 HandleMark hm; | |
5466 | |
5467 SequentialSubTasksDone* pst = space->par_seq_tasks(); | |
5468 | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5469 uint nth_task = 0; |
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5470 uint n_tasks = pst->n_tasks(); |
0 | 5471 |
12088
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5472 if (n_tasks > 0) { |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5473 assert(pst->valid(), "Uninitialized use?"); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5474 HeapWord *start, *end; |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5475 while (!pst->is_task_claimed(/* reference */ nth_task)) { |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5476 // We claimed task # nth_task; compute its boundaries. |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5477 if (chunk_top == 0) { // no samples were taken |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5478 assert(nth_task == 0 && n_tasks == 1, "Can have only 1 EdenSpace task"); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5479 start = space->bottom(); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5480 end = space->top(); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5481 } else if (nth_task == 0) { |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5482 start = space->bottom(); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5483 end = chunk_array[nth_task]; |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5484 } else if (nth_task < (uint)chunk_top) { |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5485 assert(nth_task >= 1, "Control point invariant"); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5486 start = chunk_array[nth_task - 1]; |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5487 end = chunk_array[nth_task]; |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5488 } else { |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5489 assert(nth_task == (uint)chunk_top, "Control point invariant"); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5490 start = chunk_array[chunk_top - 1]; |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5491 end = space->top(); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5492 } |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5493 MemRegion mr(start, end); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5494 // Verify that mr is in space |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5495 assert(mr.is_empty() || space->used_region().contains(mr), |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5496 "Should be in space"); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5497 // Verify that "start" is an object boundary |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5498 assert(mr.is_empty() || oop(mr.start())->is_oop(), |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5499 "Should be an oop"); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5500 space->par_oop_iterate(mr, cl); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5501 } |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5502 pst->all_tasks_completed(); |
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5503 } |
0 | 5504 } |
5505 | |
5506 void | |
5507 CMSParRemarkTask::do_dirty_card_rescan_tasks( | |
5508 CompactibleFreeListSpace* sp, int i, | |
5509 Par_MarkRefsIntoAndScanClosure* cl) { | |
5510 // Until all tasks completed: | |
5511 // . claim an unclaimed task | |
5512 // . compute region boundaries corresponding to task claimed | |
5513 // . transfer dirty bits ct->mut for that region | |
5514 // . apply rescanclosure to dirty mut bits for that region | |
5515 | |
5516 ResourceMark rm; | |
5517 HandleMark hm; | |
5518 | |
5519 OopTaskQueue* work_q = work_queue(i); | |
5520 ModUnionClosure modUnionClosure(&(_collector->_modUnionTable)); | |
5521 // CAUTION! CAUTION! CAUTION! CAUTION! CAUTION! CAUTION! CAUTION! | |
5522 // CAUTION: This closure has state that persists across calls to | |
5523 // the work method dirty_range_iterate_clear() in that it has | |
14309 | 5524 // embedded in it a (subtype of) UpwardsObjectClosure. The |
5525 // use of that state in the embedded UpwardsObjectClosure instance | |
0 | 5526 // assumes that the cards are always iterated (even if in parallel |
5527 // by several threads) in monotonically increasing order per each | |
5528 // thread. This is true of the implementation below which picks | |
5529 // card ranges (chunks) in monotonically increasing order globally | |
5530 // and, a-fortiori, in monotonically increasing order per thread | |
5531 // (the latter order being a subsequence of the former). | |
5532 // If the work code below is ever reorganized into a more chaotic | |
5533 // work-partitioning form than the current "sequential tasks" | |
5534 // paradigm, the use of that persistent state will have to be | |
5535 // revisited and modified appropriately. See also related | |
5536 // bug 4756801 work on which should examine this code to make | |
5537 // sure that the changes there do not run counter to the | |
5538 // assumptions made here and necessary for correctness and | |
5539 // efficiency. Note also that this code might yield inefficient | |
14309 | 5540 // behavior in the case of very large objects that span one or |
0 | 5541 // more work chunks. Such objects would potentially be scanned |
5542 // several times redundantly. Work on 4756801 should try and | |
5543 // address that performance anomaly if at all possible. XXX | |
5544 MemRegion full_span = _collector->_span; | |
5545 CMSBitMap* bm = &(_collector->_markBitMap); // shared | |
5546 MarkFromDirtyCardsClosure | |
5547 greyRescanClosure(_collector, full_span, // entire span of interest | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5548 sp, bm, work_q, cl); |
0 | 5549 |
5550 SequentialSubTasksDone* pst = sp->conc_par_seq_tasks(); | |
5551 assert(pst->valid(), "Uninitialized use?"); | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
5552 uint nth_task = 0; |
0 | 5553 const int alignment = CardTableModRefBS::card_size * BitsPerWord; |
5554 MemRegion span = sp->used_region(); | |
5555 HeapWord* start_addr = span.start(); | |
5556 HeapWord* end_addr = (HeapWord*)round_to((intptr_t)span.end(), | |
5557 alignment); | |
5558 const size_t chunk_size = sp->rescan_task_size(); // in HeapWord units | |
5559 assert((HeapWord*)round_to((intptr_t)start_addr, alignment) == | |
5560 start_addr, "Check alignment"); | |
5561 assert((size_t)round_to((intptr_t)chunk_size, alignment) == | |
5562 chunk_size, "Check alignment"); | |
5563 | |
5564 while (!pst->is_task_claimed(/* reference */ nth_task)) { | |
5565 // Having claimed the nth_task, compute corresponding mem-region, | |
14309 | 5566 // which is a-fortiori aligned correctly (i.e. at a MUT boundary). |
0 | 5567 // The alignment restriction ensures that we do not need any |
5568 // synchronization with other gang-workers while setting or | |
5569 // clearing bits in thus chunk of the MUT. | |
5570 MemRegion this_span = MemRegion(start_addr + nth_task*chunk_size, | |
5571 start_addr + (nth_task+1)*chunk_size); | |
5572 // The last chunk's end might be way beyond end of the | |
5573 // used region. In that case pull back appropriately. | |
5574 if (this_span.end() > end_addr) { | |
5575 this_span.set_end(end_addr); | |
5576 assert(!this_span.is_empty(), "Program logic (calculation of n_tasks)"); | |
5577 } | |
5578 // Iterate over the dirty cards covering this chunk, marking them | |
5579 // precleaned, and setting the corresponding bits in the mod union | |
5580 // table. Since we have been careful to partition at Card and MUT-word | |
5581 // boundaries no synchronization is needed between parallel threads. | |
5582 _collector->_ct->ct_bs()->dirty_card_iterate(this_span, | |
5583 &modUnionClosure); | |
5584 | |
5585 // Having transferred these marks into the modUnionTable, | |
5586 // rescan the marked objects on the dirty cards in the modUnionTable. | |
5587 // Even if this is at a synchronous collection, the initial marking | |
5588 // may have been done during an asynchronous collection so there | |
5589 // may be dirty bits in the mod-union table. | |
5590 _collector->_modUnionTable.dirty_range_iterate_clear( | |
5591 this_span, &greyRescanClosure); | |
5592 _collector->_modUnionTable.verifyNoOneBitsInRange( | |
5593 this_span.start(), | |
5594 this_span.end()); | |
5595 } | |
5596 pst->all_tasks_completed(); // declare that i am done | |
5597 } | |
5598 | |
5599 // . see if we can share work_queues with ParNew? XXX | |
5600 void | |
5601 CMSParRemarkTask::do_work_steal(int i, Par_MarkRefsIntoAndScanClosure* cl, | |
5602 int* seed) { | |
5603 OopTaskQueue* work_q = work_queue(i); | |
5604 NOT_PRODUCT(int num_steals = 0;) | |
5605 oop obj_to_scan; | |
5606 CMSBitMap* bm = &(_collector->_markBitMap); | |
5607 | |
5608 while (true) { | |
5609 // Completely finish any left over work from (an) earlier round(s) | |
5610 cl->trim_queue(0); | |
679
cea947c8a988
6819891: ParNew: Fix work queue overflow code to deal correctly with +UseCompressedOops
ysr
parents:
628
diff
changeset
|
5611 size_t num_from_overflow_list = MIN2((size_t)(work_q->max_elems() - work_q->size())/4, |
cea947c8a988
6819891: ParNew: Fix work queue overflow code to deal correctly with +UseCompressedOops
ysr
parents:
628
diff
changeset
|
5612 (size_t)ParGCDesiredObjsFromOverflowList); |
0 | 5613 // Now check if there's any work in the overflow list |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5614 // Passing ParallelGCThreads as the third parameter, no_of_gc_threads, |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5615 // only affects the number of attempts made to get work from the |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5616 // overflow list and does not affect the number of workers. Just |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5617 // pass ParallelGCThreads so this behavior is unchanged. |
0 | 5618 if (_collector->par_take_from_overflow_list(num_from_overflow_list, |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5619 work_q, |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5620 ParallelGCThreads)) { |
0 | 5621 // found something in global overflow list; |
5622 // not yet ready to go stealing work from others. | |
5623 // We'd like to assert(work_q->size() != 0, ...) | |
5624 // because we just took work from the overflow list, | |
5625 // but of course we can't since all of that could have | |
5626 // been already stolen from us. | |
5627 // "He giveth and He taketh away." | |
5628 continue; | |
5629 } | |
5630 // Verify that we have no work before we resort to stealing | |
5631 assert(work_q->size() == 0, "Have work, shouldn't steal"); | |
5632 // Try to steal from other queues that have work | |
5633 if (task_queues()->steal(i, seed, /* reference */ obj_to_scan)) { | |
5634 NOT_PRODUCT(num_steals++;) | |
5635 assert(obj_to_scan->is_oop(), "Oops, not an oop!"); | |
5636 assert(bm->isMarked((HeapWord*)obj_to_scan), "Stole an unmarked oop?"); | |
5637 // Do scanning work | |
5638 obj_to_scan->oop_iterate(cl); | |
5639 // Loop around, finish this work, and try to steal some more | |
5640 } else if (terminator()->offer_termination()) { | |
5641 break; // nirvana from the infinite cycle | |
5642 } | |
5643 } | |
5644 NOT_PRODUCT( | |
5645 if (PrintCMSStatistics != 0) { | |
5646 gclog_or_tty->print("\n\t(%d: stole %d oops)", i, num_steals); | |
5647 } | |
5648 ) | |
5649 assert(work_q->size() == 0 && _collector->overflow_list_is_empty(), | |
5650 "Else our work is not yet done"); | |
5651 } | |
5652 | |
11973
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5653 // Record object boundaries in _eden_chunk_array by sampling the eden |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5654 // top in the slow-path eden object allocation code path and record |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5655 // the boundaries, if CMSEdenChunksRecordAlways is true. If |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5656 // CMSEdenChunksRecordAlways is false, we use the other asynchronous |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5657 // sampling in sample_eden() that activates during the part of the |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5658 // preclean phase. |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5659 void CMSCollector::sample_eden_chunk() { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5660 if (CMSEdenChunksRecordAlways && _eden_chunk_array != NULL) { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5661 if (_eden_chunk_lock->try_lock()) { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5662 // Record a sample. This is the critical section. The contents |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5663 // of the _eden_chunk_array have to be non-decreasing in the |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5664 // address order. |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5665 _eden_chunk_array[_eden_chunk_index] = *_top_addr; |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5666 assert(_eden_chunk_array[_eden_chunk_index] <= *_end_addr, |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5667 "Unexpected state of Eden"); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5668 if (_eden_chunk_index == 0 || |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5669 ((_eden_chunk_array[_eden_chunk_index] > _eden_chunk_array[_eden_chunk_index-1]) && |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5670 (pointer_delta(_eden_chunk_array[_eden_chunk_index], |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5671 _eden_chunk_array[_eden_chunk_index-1]) >= CMSSamplingGrain))) { |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5672 _eden_chunk_index++; // commit sample |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5673 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5674 _eden_chunk_lock->unlock(); |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5675 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5676 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5677 } |
7b06ae405d7b
6990419: CMS Remaining work for 6572569: consistently skewed work distribution in (long) re-mark pauses
jmasa
parents:
11096
diff
changeset
|
5678 |
0 | 5679 // Return a thread-local PLAB recording array, as appropriate. |
5680 void* CMSCollector::get_data_recorder(int thr_num) { | |
5681 if (_survivor_plab_array != NULL && | |
5682 (CMSPLABRecordAlways || | |
5683 (_collectorState > Marking && _collectorState < FinalMarking))) { | |
5684 assert(thr_num < (int)ParallelGCThreads, "thr_num is out of bounds"); | |
5685 ChunkArray* ca = &_survivor_plab_array[thr_num]; | |
5686 ca->reset(); // clear it so that fresh data is recorded | |
5687 return (void*) ca; | |
5688 } else { | |
5689 return NULL; | |
5690 } | |
5691 } | |
5692 | |
5693 // Reset all the thread-local PLAB recording arrays | |
5694 void CMSCollector::reset_survivor_plab_arrays() { | |
5695 for (uint i = 0; i < ParallelGCThreads; i++) { | |
5696 _survivor_plab_array[i].reset(); | |
5697 } | |
5698 } | |
5699 | |
5700 // Merge the per-thread plab arrays into the global survivor chunk | |
5701 // array which will provide the partitioning of the survivor space | |
11975 | 5702 // for CMS initial scan and rescan. |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5703 void CMSCollector::merge_survivor_plab_arrays(ContiguousSpace* surv, |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5704 int no_of_gc_threads) { |
0 | 5705 assert(_survivor_plab_array != NULL, "Error"); |
5706 assert(_survivor_chunk_array != NULL, "Error"); | |
11975 | 5707 assert(_collectorState == FinalMarking || |
5708 (CMSParallelInitialMarkEnabled && _collectorState == InitialMarking), "Error"); | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5709 for (int j = 0; j < no_of_gc_threads; j++) { |
0 | 5710 _cursor[j] = 0; |
5711 } | |
5712 HeapWord* top = surv->top(); | |
5713 size_t i; | |
5714 for (i = 0; i < _survivor_chunk_capacity; i++) { // all sca entries | |
5715 HeapWord* min_val = top; // Higher than any PLAB address | |
5716 uint min_tid = 0; // position of min_val this round | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5717 for (int j = 0; j < no_of_gc_threads; j++) { |
0 | 5718 ChunkArray* cur_sca = &_survivor_plab_array[j]; |
5719 if (_cursor[j] == cur_sca->end()) { | |
5720 continue; | |
5721 } | |
5722 assert(_cursor[j] < cur_sca->end(), "ctl pt invariant"); | |
5723 HeapWord* cur_val = cur_sca->nth(_cursor[j]); | |
5724 assert(surv->used_region().contains(cur_val), "Out of bounds value"); | |
5725 if (cur_val < min_val) { | |
5726 min_tid = j; | |
5727 min_val = cur_val; | |
5728 } else { | |
5729 assert(cur_val < top, "All recorded addresses should be less"); | |
5730 } | |
5731 } | |
5732 // At this point min_val and min_tid are respectively | |
5733 // the least address in _survivor_plab_array[j]->nth(_cursor[j]) | |
5734 // and the thread (j) that witnesses that address. | |
5735 // We record this address in the _survivor_chunk_array[i] | |
5736 // and increment _cursor[min_tid] prior to the next round i. | |
5737 if (min_val == top) { | |
5738 break; | |
5739 } | |
5740 _survivor_chunk_array[i] = min_val; | |
5741 _cursor[min_tid]++; | |
5742 } | |
5743 // We are all done; record the size of the _survivor_chunk_array | |
5744 _survivor_chunk_index = i; // exclusive: [0, i) | |
5745 if (PrintCMSStatistics > 0) { | |
5746 gclog_or_tty->print(" (Survivor:" SIZE_FORMAT "chunks) ", i); | |
5747 } | |
5748 // Verify that we used up all the recorded entries | |
5749 #ifdef ASSERT | |
5750 size_t total = 0; | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5751 for (int j = 0; j < no_of_gc_threads; j++) { |
0 | 5752 assert(_cursor[j] == _survivor_plab_array[j].end(), "Ctl pt invariant"); |
5753 total += _cursor[j]; | |
5754 } | |
5755 assert(total == _survivor_chunk_index, "Ctl Pt Invariant"); | |
5756 // Check that the merged array is in sorted order | |
5757 if (total > 0) { | |
5758 for (size_t i = 0; i < total - 1; i++) { | |
5759 if (PrintCMSStatistics > 0) { | |
5760 gclog_or_tty->print(" (chunk" SIZE_FORMAT ":" INTPTR_FORMAT ") ", | |
5761 i, _survivor_chunk_array[i]); | |
5762 } | |
5763 assert(_survivor_chunk_array[i] < _survivor_chunk_array[i+1], | |
5764 "Not sorted"); | |
5765 } | |
5766 } | |
5767 #endif // ASSERT | |
5768 } | |
5769 | |
5770 // Set up the space's par_seq_tasks structure for work claiming | |
11975 | 5771 // for parallel initial scan and rescan of young gen. |
0 | 5772 // See ParRescanTask where this is currently used. |
5773 void | |
5774 CMSCollector:: | |
5775 initialize_sequential_subtasks_for_young_gen_rescan(int n_threads) { | |
5776 assert(n_threads > 0, "Unexpected n_threads argument"); | |
5777 DefNewGeneration* dng = (DefNewGeneration*)_young_gen; | |
5778 | |
5779 // Eden space | |
12088
cb9da55b1990
8021809: Partitioning based on eden sampling during allocation not reset correctly
jmasa
parents:
12029
diff
changeset
|
5780 if (!dng->eden()->is_empty()) { |
0 | 5781 SequentialSubTasksDone* pst = dng->eden()->par_seq_tasks(); |
5782 assert(!pst->valid(), "Clobbering existing data?"); | |
5783 // Each valid entry in [0, _eden_chunk_index) represents a task. | |
5784 size_t n_tasks = _eden_chunk_index + 1; | |
5785 assert(n_tasks == 1 || _eden_chunk_array != NULL, "Error"); | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5786 // Sets the condition for completion of the subtask (how many threads |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5787 // need to finish in order to be done). |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5788 pst->set_n_threads(n_threads); |
0 | 5789 pst->set_n_tasks((int)n_tasks); |
5790 } | |
5791 | |
5792 // Merge the survivor plab arrays into _survivor_chunk_array | |
5793 if (_survivor_plab_array != NULL) { | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5794 merge_survivor_plab_arrays(dng->from(), n_threads); |
0 | 5795 } else { |
5796 assert(_survivor_chunk_index == 0, "Error"); | |
5797 } | |
5798 | |
5799 // To space | |
5800 { | |
5801 SequentialSubTasksDone* pst = dng->to()->par_seq_tasks(); | |
5802 assert(!pst->valid(), "Clobbering existing data?"); | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5803 // Sets the condition for completion of the subtask (how many threads |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5804 // need to finish in order to be done). |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5805 pst->set_n_threads(n_threads); |
0 | 5806 pst->set_n_tasks(1); |
5807 assert(pst->valid(), "Error"); | |
5808 } | |
5809 | |
5810 // From space | |
5811 { | |
5812 SequentialSubTasksDone* pst = dng->from()->par_seq_tasks(); | |
5813 assert(!pst->valid(), "Clobbering existing data?"); | |
5814 size_t n_tasks = _survivor_chunk_index + 1; | |
5815 assert(n_tasks == 1 || _survivor_chunk_array != NULL, "Error"); | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5816 // Sets the condition for completion of the subtask (how many threads |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5817 // need to finish in order to be done). |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5818 pst->set_n_threads(n_threads); |
0 | 5819 pst->set_n_tasks((int)n_tasks); |
5820 assert(pst->valid(), "Error"); | |
5821 } | |
5822 } | |
5823 | |
5824 // Parallel version of remark | |
5825 void CMSCollector::do_remark_parallel() { | |
5826 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
5827 FlexibleWorkGang* workers = gch->workers(); |
0 | 5828 assert(workers != NULL, "Need parallel worker threads."); |
4095
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5829 // Choose to use the number of GC workers most recently set |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5830 // into "active_workers". If active_workers is not set, set it |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5831 // to ParallelGCThreads. |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5832 int n_workers = workers->active_workers(); |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5833 if (n_workers == 0) { |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5834 assert(n_workers > 0, "Should have been set during scavenge"); |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5835 n_workers = ParallelGCThreads; |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5836 workers->set_active_workers(n_workers); |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
5837 } |
0 | 5838 CompactibleFreeListSpace* cms_space = _cmsGen->cmsSpace(); |
5839 | |
5840 CMSParRemarkTask tsk(this, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5841 cms_space, |
0 | 5842 n_workers, workers, task_queues()); |
5843 | |
5844 // Set up for parallel process_strong_roots work. | |
5845 gch->set_par_threads(n_workers); | |
5846 // We won't be iterating over the cards in the card table updating | |
5847 // the younger_gen cards, so we shouldn't call the following else | |
5848 // the verification code as well as subsequent younger_refs_iterate | |
5849 // code would get confused. XXX | |
5850 // gch->rem_set()->prepare_for_younger_refs_iterate(true); // parallel | |
5851 | |
5852 // The young gen rescan work will not be done as part of | |
5853 // process_strong_roots (which currently doesn't knw how to | |
5854 // parallelize such a scan), but rather will be broken up into | |
5855 // a set of parallel tasks (via the sampling that the [abortable] | |
5856 // preclean phase did of EdenSpace, plus the [two] tasks of | |
5857 // scanning the [two] survivor spaces. Further fine-grain | |
5858 // parallelization of the scanning of the survivor spaces | |
5859 // themselves, and of precleaning of the younger gen itself | |
5860 // is deferred to the future. | |
5861 initialize_sequential_subtasks_for_young_gen_rescan(n_workers); | |
5862 | |
5863 // The dirty card rescan work is broken up into a "sequence" | |
5864 // of parallel tasks (per constituent space) that are dynamically | |
5865 // claimed by the parallel threads. | |
5866 cms_space->initialize_sequential_subtasks_for_rescan(n_workers); | |
5867 | |
5868 // It turns out that even when we're using 1 thread, doing the work in a | |
5869 // separate thread causes wide variance in run times. We can't help this | |
5870 // in the multi-threaded case, but we special-case n=1 here to get | |
5871 // repeatable measurements of the 1-thread overhead of the parallel code. | |
5872 if (n_workers > 1) { | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
5873 // Make refs discovery MT-safe, if it isn't already: it may not |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
5874 // necessarily be so, since it's possible that we are doing |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
5875 // ST marking. |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
5876 ReferenceProcessorMTDiscoveryMutator mt(ref_processor(), true); |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5877 GenCollectedHeap::StrongRootsScope srs(gch); |
0 | 5878 workers->run_task(&tsk); |
5879 } else { | |
4876
be649fefcdc2
7134655: Crash in reference processing when doing single-threaded remarking
stefank
parents:
4728
diff
changeset
|
5880 ReferenceProcessorMTDiscoveryMutator mt(ref_processor(), false); |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5881 GenCollectedHeap::StrongRootsScope srs(gch); |
0 | 5882 tsk.work(0); |
5883 } | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5884 |
0 | 5885 gch->set_par_threads(0); // 0 ==> non-parallel. |
5886 // restore, single-threaded for now, any preserved marks | |
5887 // as a result of work_q overflow | |
5888 restore_preserved_marks_if_any(); | |
5889 } | |
5890 | |
5891 // Non-parallel version of remark | |
5892 void CMSCollector::do_remark_non_parallel() { | |
5893 ResourceMark rm; | |
5894 HandleMark hm; | |
5895 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
4876
be649fefcdc2
7134655: Crash in reference processing when doing single-threaded remarking
stefank
parents:
4728
diff
changeset
|
5896 ReferenceProcessorMTDiscoveryMutator mt(ref_processor(), false); |
be649fefcdc2
7134655: Crash in reference processing when doing single-threaded remarking
stefank
parents:
4728
diff
changeset
|
5897 |
0 | 5898 MarkRefsIntoAndScanClosure |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5899 mrias_cl(_span, ref_processor(), &_markBitMap, NULL /* not precleaning */, |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5900 &_markStack, this, |
0 | 5901 false /* should_yield */, false /* not precleaning */); |
5902 MarkFromDirtyCardsClosure | |
5903 markFromDirtyCardsClosure(this, _span, | |
5904 NULL, // space is set further below | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5905 &_markBitMap, &_markStack, &mrias_cl); |
0 | 5906 { |
10405 | 5907 GCTraceTime t("grey object rescan", PrintGCDetails, false, _gc_timer_cm); |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
5908 // Iterate over the dirty cards, setting the corresponding bits in the |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
5909 // mod union table. |
0 | 5910 { |
5911 ModUnionClosure modUnionClosure(&_modUnionTable); | |
5912 _ct->ct_bs()->dirty_card_iterate( | |
5913 _cmsGen->used_region(), | |
5914 &modUnionClosure); | |
5915 } | |
5916 // Having transferred these marks into the modUnionTable, we just need | |
5917 // to rescan the marked objects on the dirty cards in the modUnionTable. | |
5918 // The initial marking may have been done during an asynchronous | |
5919 // collection so there may be dirty bits in the mod-union table. | |
5920 const int alignment = | |
5921 CardTableModRefBS::card_size * BitsPerWord; | |
5922 { | |
5923 // ... First handle dirty cards in CMS gen | |
5924 markFromDirtyCardsClosure.set_space(_cmsGen->cmsSpace()); | |
5925 MemRegion ur = _cmsGen->used_region(); | |
5926 HeapWord* lb = ur.start(); | |
5927 HeapWord* ub = (HeapWord*)round_to((intptr_t)ur.end(), alignment); | |
5928 MemRegion cms_span(lb, ub); | |
5929 _modUnionTable.dirty_range_iterate_clear(cms_span, | |
5930 &markFromDirtyCardsClosure); | |
5931 verify_work_stacks_empty(); | |
5932 if (PrintCMSStatistics != 0) { | |
5933 gclog_or_tty->print(" (re-scanned "SIZE_FORMAT" dirty cards in cms gen) ", | |
5934 markFromDirtyCardsClosure.num_dirty_cards()); | |
5935 } | |
5936 } | |
5937 } | |
5938 if (VerifyDuringGC && | |
5939 GenCollectedHeap::heap()->total_collections() >= VerifyGCStartAt) { | |
5940 HandleMark hm; // Discard invalid handles created during verification | |
6865
4202510ee0fe
8000831: Heap verification output incorrect/incomplete
johnc
parents:
6787
diff
changeset
|
5941 Universe::verify(); |
0 | 5942 } |
5943 { | |
10405 | 5944 GCTraceTime t("root rescan", PrintGCDetails, false, _gc_timer_cm); |
0 | 5945 |
5946 verify_work_stacks_empty(); | |
5947 | |
5948 gch->rem_set()->prepare_for_younger_refs_iterate(false); // Not parallel. | |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5949 GenCollectedHeap::StrongRootsScope srs(gch); |
0 | 5950 gch->gen_process_strong_roots(_cmsGen->level(), |
5951 true, // younger gens as roots | |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5952 false, // use the local StrongRootsScope |
0 | 5953 SharedHeap::ScanningOption(roots_scanning_options()), |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5954 &mrias_cl, |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5955 NULL, |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5956 NULL); // The dirty klasses will be handled below |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5957 |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5958 assert(should_unload_classes() |
14308
870aedf4ba4f
8032379: Remove the is_scavenging flag to process_strong_roots
mgerdin
parents:
13400
diff
changeset
|
5959 || (roots_scanning_options() & SharedHeap::SO_AllCodeCache), |
989
148e5441d916
6863023: need non-perm oops in code cache for JSR 292
jrose
parents:
798
diff
changeset
|
5960 "if we didn't scan the code cache, we have to be ready to drop nmethods with expired weak oops"); |
0 | 5961 } |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5962 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5963 { |
10405 | 5964 GCTraceTime t("visit unhandled CLDs", PrintGCDetails, false, _gc_timer_cm); |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5965 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5966 verify_work_stacks_empty(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5967 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5968 // Scan all class loader data objects that might have been introduced |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5969 // during concurrent marking. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5970 ResourceMark rm; |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5971 GrowableArray<ClassLoaderData*>* array = ClassLoaderDataGraph::new_clds(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5972 for (int i = 0; i < array->length(); i++) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5973 mrias_cl.do_class_loader_data(array->at(i)); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5974 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5975 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5976 // We don't need to keep track of new CLDs anymore. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5977 ClassLoaderDataGraph::remember_new_clds(false); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5978 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5979 verify_work_stacks_empty(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5980 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5981 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5982 { |
10405 | 5983 GCTraceTime t("dirty klass scan", PrintGCDetails, false, _gc_timer_cm); |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5984 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5985 verify_work_stacks_empty(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5986 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5987 RemarkKlassClosure remark_klass_closure(&mrias_cl); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5988 ClassLoaderDataGraph::classes_do(&remark_klass_closure); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5989 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5990 verify_work_stacks_empty(); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5991 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5992 |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5993 // We might have added oops to ClassLoaderData::_handles during the |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5994 // concurrent marking phase. These oops point to newly allocated objects |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5995 // that are guaranteed to be kept alive. Either by the direct allocation |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5996 // code, or when the young collector processes the strong roots. Hence, |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5997 // we don't have to revisit the _handles block during the remark phase. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
5998 |
0 | 5999 verify_work_stacks_empty(); |
6000 // Restore evacuated mark words, if any, used for overflow list links | |
6001 if (!CMSOverflowEarlyRestoration) { | |
6002 restore_preserved_marks_if_any(); | |
6003 } | |
6004 verify_overflow_empty(); | |
6005 } | |
6006 | |
6007 //////////////////////////////////////////////////////// | |
6008 // Parallel Reference Processing Task Proxy Class | |
6009 //////////////////////////////////////////////////////// | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6010 class CMSRefProcTaskProxy: public AbstractGangTaskWOopQueues { |
0 | 6011 typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask; |
6012 CMSCollector* _collector; | |
6013 CMSBitMap* _mark_bit_map; | |
143
b5489bb705c9
6662086: 6u4+, 7b11+: CMS never clears referents when -XX:+ParallelRefProcEnabled
ysr
parents:
113
diff
changeset
|
6014 const MemRegion _span; |
0 | 6015 ProcessTask& _task; |
6016 | |
6017 public: | |
6018 CMSRefProcTaskProxy(ProcessTask& task, | |
6019 CMSCollector* collector, | |
6020 const MemRegion& span, | |
6021 CMSBitMap* mark_bit_map, | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6022 AbstractWorkGang* workers, |
0 | 6023 OopTaskQueueSet* task_queues): |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
6024 // XXX Should superclass AGTWOQ also know about AWG since it knows |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
6025 // about the task_queues used by the AWG? Then it could initialize |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
6026 // the terminator() object. See 6984287. The set_for_termination() |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
6027 // below is a temporary band-aid for the regression in 6984287. |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6028 AbstractGangTaskWOopQueues("Process referents by policy in parallel", |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6029 task_queues), |
0 | 6030 _task(task), |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6031 _collector(collector), _span(span), _mark_bit_map(mark_bit_map) |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
6032 { |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
6033 assert(_collector->_span.equals(_span) && !_span.is_empty(), |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
6034 "Inconsistency in _span"); |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
6035 set_for_termination(workers->active_workers()); |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
2365
diff
changeset
|
6036 } |
0 | 6037 |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6038 OopTaskQueueSet* task_queues() { return queues(); } |
0 | 6039 |
6040 OopTaskQueue* work_queue(int i) { return task_queues()->queue(i); } | |
6041 | |
6042 void do_work_steal(int i, | |
6043 CMSParDrainMarkingStackClosure* drain, | |
6044 CMSParKeepAliveClosure* keep_alive, | |
6045 int* seed); | |
6046 | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6047 virtual void work(uint worker_id); |
0 | 6048 }; |
6049 | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6050 void CMSRefProcTaskProxy::work(uint worker_id) { |
143
b5489bb705c9
6662086: 6u4+, 7b11+: CMS never clears referents when -XX:+ParallelRefProcEnabled
ysr
parents:
113
diff
changeset
|
6051 assert(_collector->_span.equals(_span), "Inconsistency in _span"); |
0 | 6052 CMSParKeepAliveClosure par_keep_alive(_collector, _span, |
935 | 6053 _mark_bit_map, |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6054 work_queue(worker_id)); |
0 | 6055 CMSParDrainMarkingStackClosure par_drain_stack(_collector, _span, |
935 | 6056 _mark_bit_map, |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6057 work_queue(worker_id)); |
143
b5489bb705c9
6662086: 6u4+, 7b11+: CMS never clears referents when -XX:+ParallelRefProcEnabled
ysr
parents:
113
diff
changeset
|
6058 CMSIsAliveClosure is_alive_closure(_span, _mark_bit_map); |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6059 _task.work(worker_id, is_alive_closure, par_keep_alive, par_drain_stack); |
0 | 6060 if (_task.marks_oops_alive()) { |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6061 do_work_steal(worker_id, &par_drain_stack, &par_keep_alive, |
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6062 _collector->hash_seed(worker_id)); |
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6063 } |
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6064 assert(work_queue(worker_id)->size() == 0, "work_queue should be empty"); |
0 | 6065 assert(_collector->_overflow_list == NULL, "non-empty _overflow_list"); |
6066 } | |
6067 | |
6068 class CMSRefEnqueueTaskProxy: public AbstractGangTask { | |
6069 typedef AbstractRefProcTaskExecutor::EnqueueTask EnqueueTask; | |
6070 EnqueueTask& _task; | |
6071 | |
6072 public: | |
6073 CMSRefEnqueueTaskProxy(EnqueueTask& task) | |
6074 : AbstractGangTask("Enqueue reference objects in parallel"), | |
6075 _task(task) | |
6076 { } | |
6077 | |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6078 virtual void work(uint worker_id) |
0 | 6079 { |
4728
441e946dc1af
7121618: Change type of number of GC workers to unsigned int.
jmasa
parents:
4128
diff
changeset
|
6080 _task.work(worker_id); |
0 | 6081 } |
6082 }; | |
6083 | |
6084 CMSParKeepAliveClosure::CMSParKeepAliveClosure(CMSCollector* collector, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6085 MemRegion span, CMSBitMap* bit_map, OopTaskQueue* work_queue): |
0 | 6086 _span(span), |
6087 _bit_map(bit_map), | |
6088 _work_queue(work_queue), | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6089 _mark_and_push(collector, span, bit_map, work_queue), |
0 | 6090 _low_water_mark(MIN2((uint)(work_queue->max_elems()/4), |
6091 (uint)(CMSWorkQueueDrainThreshold * ParallelGCThreads))) | |
6092 { } | |
6093 | |
6094 // . see if we can share work_queues with ParNew? XXX | |
6095 void CMSRefProcTaskProxy::do_work_steal(int i, | |
6096 CMSParDrainMarkingStackClosure* drain, | |
6097 CMSParKeepAliveClosure* keep_alive, | |
6098 int* seed) { | |
6099 OopTaskQueue* work_q = work_queue(i); | |
6100 NOT_PRODUCT(int num_steals = 0;) | |
6101 oop obj_to_scan; | |
6102 | |
6103 while (true) { | |
6104 // Completely finish any left over work from (an) earlier round(s) | |
6105 drain->trim_queue(0); | |
679
cea947c8a988
6819891: ParNew: Fix work queue overflow code to deal correctly with +UseCompressedOops
ysr
parents:
628
diff
changeset
|
6106 size_t num_from_overflow_list = MIN2((size_t)(work_q->max_elems() - work_q->size())/4, |
cea947c8a988
6819891: ParNew: Fix work queue overflow code to deal correctly with +UseCompressedOops
ysr
parents:
628
diff
changeset
|
6107 (size_t)ParGCDesiredObjsFromOverflowList); |
0 | 6108 // Now check if there's any work in the overflow list |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6109 // Passing ParallelGCThreads as the third parameter, no_of_gc_threads, |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6110 // only affects the number of attempts made to get work from the |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6111 // overflow list and does not affect the number of workers. Just |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6112 // pass ParallelGCThreads so this behavior is unchanged. |
0 | 6113 if (_collector->par_take_from_overflow_list(num_from_overflow_list, |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6114 work_q, |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6115 ParallelGCThreads)) { |
0 | 6116 // Found something in global overflow list; |
6117 // not yet ready to go stealing work from others. | |
6118 // We'd like to assert(work_q->size() != 0, ...) | |
6119 // because we just took work from the overflow list, | |
6120 // but of course we can't, since all of that might have | |
6121 // been already stolen from us. | |
6122 continue; | |
6123 } | |
6124 // Verify that we have no work before we resort to stealing | |
6125 assert(work_q->size() == 0, "Have work, shouldn't steal"); | |
6126 // Try to steal from other queues that have work | |
6127 if (task_queues()->steal(i, seed, /* reference */ obj_to_scan)) { | |
6128 NOT_PRODUCT(num_steals++;) | |
6129 assert(obj_to_scan->is_oop(), "Oops, not an oop!"); | |
6130 assert(_mark_bit_map->isMarked((HeapWord*)obj_to_scan), "Stole an unmarked oop?"); | |
6131 // Do scanning work | |
6132 obj_to_scan->oop_iterate(keep_alive); | |
6133 // Loop around, finish this work, and try to steal some more | |
6134 } else if (terminator()->offer_termination()) { | |
6135 break; // nirvana from the infinite cycle | |
6136 } | |
6137 } | |
6138 NOT_PRODUCT( | |
6139 if (PrintCMSStatistics != 0) { | |
6140 gclog_or_tty->print("\n\t(%d: stole %d oops)", i, num_steals); | |
6141 } | |
6142 ) | |
6143 } | |
6144 | |
6145 void CMSRefProcTaskExecutor::execute(ProcessTask& task) | |
6146 { | |
6147 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6148 FlexibleWorkGang* workers = gch->workers(); |
0 | 6149 assert(workers != NULL, "Need parallel worker threads."); |
6150 CMSRefProcTaskProxy rp_task(task, &_collector, | |
6151 _collector.ref_processor()->span(), | |
6152 _collector.markBitMap(), | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6153 workers, _collector.task_queues()); |
0 | 6154 workers->run_task(&rp_task); |
6155 } | |
6156 | |
6157 void CMSRefProcTaskExecutor::execute(EnqueueTask& task) | |
6158 { | |
6159 | |
6160 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6161 FlexibleWorkGang* workers = gch->workers(); |
0 | 6162 assert(workers != NULL, "Need parallel worker threads."); |
6163 CMSRefEnqueueTaskProxy enq_task(task); | |
6164 workers->run_task(&enq_task); | |
6165 } | |
6166 | |
6167 void CMSCollector::refProcessingWork(bool asynch, bool clear_all_soft_refs) { | |
6168 | |
6169 ResourceMark rm; | |
6170 HandleMark hm; | |
6171 | |
6172 ReferenceProcessor* rp = ref_processor(); | |
6173 assert(rp->span().equals(_span), "Spans should be equal"); | |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
6174 assert(!rp->enqueuing_is_done(), "Enqueuing should not be complete"); |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
6175 // Process weak references. |
457
27a80744a83b
6778647: snap(), snap_policy() should be renamed setup(), setup_policy()
ysr
parents:
453
diff
changeset
|
6176 rp->setup_policy(clear_all_soft_refs); |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
6177 verify_work_stacks_empty(); |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
6178 |
0 | 6179 CMSKeepAliveClosure cmsKeepAliveClosure(this, _span, &_markBitMap, |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6180 &_markStack, false /* !preclean */); |
0 | 6181 CMSDrainMarkingStackClosure cmsDrainMarkingStackClosure(this, |
6182 _span, &_markBitMap, &_markStack, | |
452
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
6183 &cmsKeepAliveClosure, false /* !preclean */); |
0 | 6184 { |
10405 | 6185 GCTraceTime t("weak refs processing", PrintGCDetails, false, _gc_timer_cm); |
6186 | |
6187 ReferenceProcessorStats stats; | |
0 | 6188 if (rp->processing_is_mt()) { |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6189 // Set the degree of MT here. If the discovery is done MT, there |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6190 // may have been a different number of threads doing the discovery |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6191 // and a different number of discovered lists may have Ref objects. |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6192 // That is OK as long as the Reference lists are balanced (see |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6193 // balance_all_queues() and balance_queues()). |
4095
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6194 GenCollectedHeap* gch = GenCollectedHeap::heap(); |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6195 int active_workers = ParallelGCThreads; |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6196 FlexibleWorkGang* workers = gch->workers(); |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6197 if (workers != NULL) { |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6198 active_workers = workers->active_workers(); |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6199 // The expectation is that active_workers will have already |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6200 // been set to a reasonable value. If it has not been set, |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6201 // investigate. |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6202 assert(active_workers > 0, "Should have been set during scavenge"); |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6203 } |
bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
jmasa
parents:
3979
diff
changeset
|
6204 rp->set_active_mt_degree(active_workers); |
0 | 6205 CMSRefProcTaskExecutor task_executor(*this); |
10405 | 6206 stats = rp->process_discovered_references(&_is_alive_closure, |
0 | 6207 &cmsKeepAliveClosure, |
6208 &cmsDrainMarkingStackClosure, | |
10405 | 6209 &task_executor, |
6210 _gc_timer_cm); | |
0 | 6211 } else { |
10405 | 6212 stats = rp->process_discovered_references(&_is_alive_closure, |
0 | 6213 &cmsKeepAliveClosure, |
6214 &cmsDrainMarkingStackClosure, | |
10405 | 6215 NULL, |
6216 _gc_timer_cm); | |
6217 } | |
6218 _gc_tracer_cm->report_gc_reference_stats(stats); | |
6219 | |
10188
2f50bc369470
8013160: NPG: Remove unnecessary mark stack draining after CodeCache::do_unloading
stefank
parents:
10186
diff
changeset
|
6220 } |
2f50bc369470
8013160: NPG: Remove unnecessary mark stack draining after CodeCache::do_unloading
stefank
parents:
10186
diff
changeset
|
6221 |
2f50bc369470
8013160: NPG: Remove unnecessary mark stack draining after CodeCache::do_unloading
stefank
parents:
10186
diff
changeset
|
6222 // This is the point where the entire marking should have completed. |
2f50bc369470
8013160: NPG: Remove unnecessary mark stack draining after CodeCache::do_unloading
stefank
parents:
10186
diff
changeset
|
6223 verify_work_stacks_empty(); |
0 | 6224 |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
6225 if (should_unload_classes()) { |
0 | 6226 { |
10405 | 6227 GCTraceTime t("class unloading", PrintGCDetails, false, _gc_timer_cm); |
0 | 6228 |
10188
2f50bc369470
8013160: NPG: Remove unnecessary mark stack draining after CodeCache::do_unloading
stefank
parents:
10186
diff
changeset
|
6229 // Unload classes and purge the SystemDictionary. |
0 | 6230 bool purged_class = SystemDictionary::do_unloading(&_is_alive_closure); |
6231 | |
10188
2f50bc369470
8013160: NPG: Remove unnecessary mark stack draining after CodeCache::do_unloading
stefank
parents:
10186
diff
changeset
|
6232 // Unload nmethods. |
6787
8966c2d65d96
7200470: KeepAliveClosure not needed in CodeCache::do_unloading
brutisso
parents:
6755
diff
changeset
|
6233 CodeCache::do_unloading(&_is_alive_closure, purged_class); |
0 | 6234 |
10188
2f50bc369470
8013160: NPG: Remove unnecessary mark stack draining after CodeCache::do_unloading
stefank
parents:
10186
diff
changeset
|
6235 // Prune dead klasses from subklass/sibling/implementor lists. |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6236 Klass::clean_weak_klass_links(&_is_alive_closure); |
0 | 6237 } |
6238 | |
6239 { | |
10405 | 6240 GCTraceTime t("scrub symbol table", PrintGCDetails, false, _gc_timer_cm); |
2177
3582bf76420e
6990754: Use native memory and reference counting to implement SymbolTable
coleenp
parents:
2147
diff
changeset
|
6241 // Clean up unreferenced symbols in symbol table. |
3582bf76420e
6990754: Use native memory and reference counting to implement SymbolTable
coleenp
parents:
2147
diff
changeset
|
6242 SymbolTable::unlink(); |
0 | 6243 } |
6244 } | |
6245 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6246 // CMS doesn't use the StringTable as hard roots when class unloading is turned off. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6247 // Need to check if we really scanned the StringTable. |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6248 if ((roots_scanning_options() & SharedHeap::SO_Strings) == 0) { |
10405 | 6249 GCTraceTime t("scrub string table", PrintGCDetails, false, _gc_timer_cm); |
10188
2f50bc369470
8013160: NPG: Remove unnecessary mark stack draining after CodeCache::do_unloading
stefank
parents:
10186
diff
changeset
|
6250 // Delete entries for dead interned strings. |
2379
b099aaf51bf8
6962931: move interned strings out of the perm gen
jcoomes
parents:
2369
diff
changeset
|
6251 StringTable::unlink(&_is_alive_closure); |
b099aaf51bf8
6962931: move interned strings out of the perm gen
jcoomes
parents:
2369
diff
changeset
|
6252 } |
b099aaf51bf8
6962931: move interned strings out of the perm gen
jcoomes
parents:
2369
diff
changeset
|
6253 |
0 | 6254 // Restore any preserved marks as a result of mark stack or |
6255 // work queue overflow | |
6256 restore_preserved_marks_if_any(); // done single-threaded for now | |
6257 | |
6258 rp->set_enqueuing_is_done(true); | |
6259 if (rp->processing_is_mt()) { | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
6260 rp->balance_all_queues(); |
0 | 6261 CMSRefProcTaskExecutor task_executor(*this); |
6262 rp->enqueue_discovered_references(&task_executor); | |
6263 } else { | |
6264 rp->enqueue_discovered_references(NULL); | |
6265 } | |
6266 rp->verify_no_references_recorded(); | |
6267 assert(!rp->discovery_enabled(), "should have been disabled"); | |
6268 } | |
6269 | |
6270 #ifndef PRODUCT | |
6271 void CMSCollector::check_correct_thread_executing() { | |
6272 Thread* t = Thread::current(); | |
6273 // Only the VM thread or the CMS thread should be here. | |
6274 assert(t->is_ConcurrentGC_thread() || t->is_VM_thread(), | |
6275 "Unexpected thread type"); | |
6276 // If this is the vm thread, the foreground process | |
6277 // should not be waiting. Note that _foregroundGCIsActive is | |
6278 // true while the foreground collector is waiting. | |
6279 if (_foregroundGCShouldWait) { | |
6280 // We cannot be the VM thread | |
6281 assert(t->is_ConcurrentGC_thread(), | |
6282 "Should be CMS thread"); | |
6283 } else { | |
6284 // We can be the CMS thread only if we are in a stop-world | |
6285 // phase of CMS collection. | |
6286 if (t->is_ConcurrentGC_thread()) { | |
6287 assert(_collectorState == InitialMarking || | |
6288 _collectorState == FinalMarking, | |
6289 "Should be a stop-world phase"); | |
6290 // The CMS thread should be holding the CMS_token. | |
6291 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
6292 "Potential interference with concurrently " | |
6293 "executing VM thread"); | |
6294 } | |
6295 } | |
6296 } | |
6297 #endif | |
6298 | |
6299 void CMSCollector::sweep(bool asynch) { | |
6300 assert(_collectorState == Sweeping, "just checking"); | |
6301 check_correct_thread_executing(); | |
6302 verify_work_stacks_empty(); | |
6303 verify_overflow_empty(); | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6304 increment_sweep_count(); |
3356
78542e2b5e35
7036199: Adding a notification to the implementation of GarbageCollectorMXBeans
fparain
parents:
3293
diff
changeset
|
6305 TraceCMSMemoryManagerStats tms(_collectorState,GenCollectedHeap::heap()->gc_cause()); |
1703
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
6306 |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6307 _inter_sweep_timer.stop(); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6308 _inter_sweep_estimate.sample(_inter_sweep_timer.seconds()); |
0 | 6309 size_policy()->avg_cms_free_at_sweep()->sample(_cmsGen->free()); |
6310 | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6311 assert(!_intra_sweep_timer.is_active(), "Should not be active"); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6312 _intra_sweep_timer.reset(); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6313 _intra_sweep_timer.start(); |
0 | 6314 if (asynch) { |
6315 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
6316 CMSPhaseAccounting pa(this, "sweep", !PrintGCDetails); | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6317 // First sweep the old gen |
0 | 6318 { |
6319 CMSTokenSyncWithLocks ts(true, _cmsGen->freelistLock(), | |
6320 bitMapLock()); | |
6321 sweepWork(_cmsGen, asynch); | |
6322 } | |
6323 | |
6324 // Update Universe::_heap_*_at_gc figures. | |
6325 // We need all the free list locks to make the abstract state | |
6326 // transition from Sweeping to Resetting. See detailed note | |
6327 // further below. | |
6328 { | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6329 CMSTokenSyncWithLocks ts(true, _cmsGen->freelistLock()); |
0 | 6330 // Update heap occupancy information which is used as |
6331 // input to soft ref clearing policy at the next gc. | |
6332 Universe::update_heap_info_at_gc(); | |
6333 _collectorState = Resizing; | |
6334 } | |
6335 } else { | |
6336 // already have needed locks | |
6337 sweepWork(_cmsGen, asynch); | |
6338 // Update heap occupancy information which is used as | |
6339 // input to soft ref clearing policy at the next gc. | |
6340 Universe::update_heap_info_at_gc(); | |
6341 _collectorState = Resizing; | |
6342 } | |
6343 verify_work_stacks_empty(); | |
6344 verify_overflow_empty(); | |
6345 | |
8784
79af1312fc2c
8005602: NPG: classunloading does not happen while CMS GC with -XX:+CMSClassUnloadingEnabled is used
mgerdin
parents:
8740
diff
changeset
|
6346 if (should_unload_classes()) { |
79af1312fc2c
8005602: NPG: classunloading does not happen while CMS GC with -XX:+CMSClassUnloadingEnabled is used
mgerdin
parents:
8740
diff
changeset
|
6347 ClassLoaderDataGraph::purge(); |
79af1312fc2c
8005602: NPG: classunloading does not happen while CMS GC with -XX:+CMSClassUnloadingEnabled is used
mgerdin
parents:
8740
diff
changeset
|
6348 } |
79af1312fc2c
8005602: NPG: classunloading does not happen while CMS GC with -XX:+CMSClassUnloadingEnabled is used
mgerdin
parents:
8740
diff
changeset
|
6349 |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6350 _intra_sweep_timer.stop(); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6351 _intra_sweep_estimate.sample(_intra_sweep_timer.seconds()); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6352 |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6353 _inter_sweep_timer.reset(); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6354 _inter_sweep_timer.start(); |
0 | 6355 |
14309 | 6356 // We need to use a monotonically non-decreasing time in ms |
4911 | 6357 // or we will see time-warp warnings and os::javaTimeMillis() |
6358 // does not guarantee monotonicity. | |
6359 jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC; | |
6360 update_time_of_last_gc(now); | |
0 | 6361 |
6362 // NOTE on abstract state transitions: | |
6363 // Mutators allocate-live and/or mark the mod-union table dirty | |
6364 // based on the state of the collection. The former is done in | |
6365 // the interval [Marking, Sweeping] and the latter in the interval | |
6366 // [Marking, Sweeping). Thus the transitions into the Marking state | |
6367 // and out of the Sweeping state must be synchronously visible | |
6368 // globally to the mutators. | |
6369 // The transition into the Marking state happens with the world | |
6370 // stopped so the mutators will globally see it. Sweeping is | |
6371 // done asynchronously by the background collector so the transition | |
6372 // from the Sweeping state to the Resizing state must be done | |
6373 // under the freelistLock (as is the check for whether to | |
6374 // allocate-live and whether to dirty the mod-union table). | |
6375 assert(_collectorState == Resizing, "Change of collector state to" | |
6376 " Resizing must be done under the freelistLocks (plural)"); | |
6377 | |
1888
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
6378 // Now that sweeping has been completed, we clear |
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
6379 // the incremental_collection_failed flag, |
0 | 6380 // thus inviting a younger gen collection to promote into |
6381 // this generation. If such a promotion may still fail, | |
6382 // the flag will be set again when a young collection is | |
6383 // attempted. | |
6384 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
1888
a7214d79fcf1
6896603: CMS/GCH: collection_attempt_is_safe() ergo should use more recent data
ysr
parents:
1837
diff
changeset
|
6385 gch->clear_incremental_collection_failed(); // Worth retrying as fresh space may have been freed up |
0 | 6386 gch->update_full_collections_completed(_collection_count_start); |
6387 } | |
6388 | |
6389 // FIX ME!!! Looks like this belongs in CFLSpace, with | |
6390 // CMSGen merely delegating to it. | |
6391 void ConcurrentMarkSweepGeneration::setNearLargestChunk() { | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6392 double nearLargestPercent = FLSLargestBlockCoalesceProximity; |
0 | 6393 HeapWord* minAddr = _cmsSpace->bottom(); |
6394 HeapWord* largestAddr = | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
6395 (HeapWord*) _cmsSpace->dictionary()->find_largest_dict(); |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6396 if (largestAddr == NULL) { |
0 | 6397 // The dictionary appears to be empty. In this case |
6398 // try to coalesce at the end of the heap. | |
6399 largestAddr = _cmsSpace->end(); | |
6400 } | |
6401 size_t largestOffset = pointer_delta(largestAddr, minAddr); | |
6402 size_t nearLargestOffset = | |
6403 (size_t)((double)largestOffset * nearLargestPercent) - MinChunkSize; | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6404 if (PrintFLSStatistics != 0) { |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6405 gclog_or_tty->print_cr( |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6406 "CMS: Large Block: " PTR_FORMAT ";" |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6407 " Proximity: " PTR_FORMAT " -> " PTR_FORMAT, |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6408 largestAddr, |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6409 _cmsSpace->nearLargestChunk(), minAddr + nearLargestOffset); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6410 } |
0 | 6411 _cmsSpace->set_nearLargestChunk(minAddr + nearLargestOffset); |
6412 } | |
6413 | |
6414 bool ConcurrentMarkSweepGeneration::isNearLargestChunk(HeapWord* addr) { | |
6415 return addr >= _cmsSpace->nearLargestChunk(); | |
6416 } | |
6417 | |
6418 FreeChunk* ConcurrentMarkSweepGeneration::find_chunk_at_end() { | |
6419 return _cmsSpace->find_chunk_at_end(); | |
6420 } | |
6421 | |
6422 void ConcurrentMarkSweepGeneration::update_gc_stats(int current_level, | |
6423 bool full) { | |
6424 // The next lower level has been collected. Gather any statistics | |
6425 // that are of interest at this point. | |
6426 if (!full && (current_level + 1) == level()) { | |
6427 // Gather statistics on the young generation collection. | |
6428 collector()->stats().record_gc0_end(used()); | |
6429 } | |
6430 } | |
6431 | |
6432 CMSAdaptiveSizePolicy* ConcurrentMarkSweepGeneration::size_policy() { | |
6433 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
6434 assert(gch->kind() == CollectedHeap::GenCollectedHeap, | |
6435 "Wrong type of heap"); | |
6436 CMSAdaptiveSizePolicy* sp = (CMSAdaptiveSizePolicy*) | |
6437 gch->gen_policy()->size_policy(); | |
6438 assert(sp->is_gc_cms_adaptive_size_policy(), | |
6439 "Wrong type of size policy"); | |
6440 return sp; | |
6441 } | |
6442 | |
6443 void ConcurrentMarkSweepGeneration::rotate_debug_collection_type() { | |
6444 if (PrintGCDetails && Verbose) { | |
6445 gclog_or_tty->print("Rotate from %d ", _debug_collection_type); | |
6446 } | |
6447 _debug_collection_type = (CollectionTypes) (_debug_collection_type + 1); | |
6448 _debug_collection_type = | |
6449 (CollectionTypes) (_debug_collection_type % Unknown_collection_type); | |
6450 if (PrintGCDetails && Verbose) { | |
6451 gclog_or_tty->print_cr("to %d ", _debug_collection_type); | |
6452 } | |
6453 } | |
6454 | |
6455 void CMSCollector::sweepWork(ConcurrentMarkSweepGeneration* gen, | |
6456 bool asynch) { | |
6457 // We iterate over the space(s) underlying this generation, | |
6458 // checking the mark bit map to see if the bits corresponding | |
6459 // to specific blocks are marked or not. Blocks that are | |
6460 // marked are live and are not swept up. All remaining blocks | |
6461 // are swept up, with coalescing on-the-fly as we sweep up | |
6462 // contiguous free and/or garbage blocks: | |
6463 // We need to ensure that the sweeper synchronizes with allocators | |
6464 // and stop-the-world collectors. In particular, the following | |
6465 // locks are used: | |
6466 // . CMS token: if this is held, a stop the world collection cannot occur | |
6467 // . freelistLock: if this is held no allocation can occur from this | |
6468 // generation by another thread | |
6469 // . bitMapLock: if this is held, no other thread can access or update | |
6470 // | |
6471 | |
6472 // Note that we need to hold the freelistLock if we use | |
6473 // block iterate below; else the iterator might go awry if | |
6474 // a mutator (or promotion) causes block contents to change | |
6475 // (for instance if the allocator divvies up a block). | |
6476 // If we hold the free list lock, for all practical purposes | |
6477 // young generation GC's can't occur (they'll usually need to | |
6478 // promote), so we might as well prevent all young generation | |
6479 // GC's while we do a sweeping step. For the same reason, we might | |
6480 // as well take the bit map lock for the entire duration | |
6481 | |
6482 // check that we hold the requisite locks | |
6483 assert(have_cms_token(), "Should hold cms token"); | |
6484 assert( (asynch && ConcurrentMarkSweepThread::cms_thread_has_cms_token()) | |
6485 || (!asynch && ConcurrentMarkSweepThread::vm_thread_has_cms_token()), | |
6486 "Should possess CMS token to sweep"); | |
6487 assert_lock_strong(gen->freelistLock()); | |
6488 assert_lock_strong(bitMapLock()); | |
6489 | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6490 assert(!_inter_sweep_timer.is_active(), "Was switched off in an outer context"); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6491 assert(_intra_sweep_timer.is_active(), "Was switched on in an outer context"); |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6492 gen->cmsSpace()->beginSweepFLCensus((float)(_inter_sweep_timer.seconds()), |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6493 _inter_sweep_estimate.padded_average(), |
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6494 _intra_sweep_estimate.padded_average()); |
0 | 6495 gen->setNearLargestChunk(); |
6496 | |
6497 { | |
6498 SweepClosure sweepClosure(this, gen, &_markBitMap, | |
6499 CMSYield && asynch); | |
6500 gen->cmsSpace()->blk_iterate_careful(&sweepClosure); | |
6501 // We need to free-up/coalesce garbage/blocks from a | |
6502 // co-terminal free run. This is done in the SweepClosure | |
6503 // destructor; so, do not remove this scope, else the | |
6504 // end-of-sweep-census below will be off by a little bit. | |
6505 } | |
6506 gen->cmsSpace()->sweep_completed(); | |
1145
e018e6884bd8
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
1085
diff
changeset
|
6507 gen->cmsSpace()->endSweepFLCensus(sweep_count()); |
94
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
6508 if (should_unload_classes()) { // unloaded classes this cycle, |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
6509 _concurrent_cycles_since_last_unload = 0; // ... reset count |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
6510 } else { // did not unload classes, |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
6511 _concurrent_cycles_since_last_unload++; // ... increment count |
0834225a7916
6634032: CMS: Need CMSInitiatingPermOccupancyFraction for perm, divorcing from CMSInitiatingOccupancyFraction
ysr
parents:
9
diff
changeset
|
6512 } |
0 | 6513 } |
6514 | |
6515 // Reset CMS data structures (for now just the marking bit map) | |
6516 // preparatory for the next cycle. | |
6517 void CMSCollector::reset(bool asynch) { | |
6518 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
6519 CMSAdaptiveSizePolicy* sp = size_policy(); | |
6520 AdaptiveSizePolicyOutput(sp, gch->total_collections()); | |
6521 if (asynch) { | |
6522 CMSTokenSyncWithLocks ts(true, bitMapLock()); | |
6523 | |
6524 // If the state is not "Resetting", the foreground thread | |
6525 // has done a collection and the resetting. | |
6526 if (_collectorState != Resetting) { | |
6527 assert(_collectorState == Idling, "The state should only change" | |
6528 " because the foreground collector has finished the collection"); | |
6529 return; | |
6530 } | |
6531 | |
6532 // Clear the mark bitmap (no grey objects to start with) | |
6533 // for the next cycle. | |
6534 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
6535 CMSPhaseAccounting cmspa(this, "reset", !PrintGCDetails); | |
6536 | |
6537 HeapWord* curAddr = _markBitMap.startWord(); | |
6538 while (curAddr < _markBitMap.endWord()) { | |
6539 size_t remaining = pointer_delta(_markBitMap.endWord(), curAddr); | |
6540 MemRegion chunk(curAddr, MIN2(CMSBitMapYieldQuantum, remaining)); | |
6541 _markBitMap.clear_large_range(chunk); | |
6542 if (ConcurrentMarkSweepThread::should_yield() && | |
6543 !foregroundGCIsActive() && | |
6544 CMSYield) { | |
6545 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
6546 "CMS thread should hold CMS token"); | |
6547 assert_lock_strong(bitMapLock()); | |
6548 bitMapLock()->unlock(); | |
6549 ConcurrentMarkSweepThread::desynchronize(true); | |
6550 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
6551 stopTimer(); | |
6552 if (PrintCMSStatistics != 0) { | |
6553 incrementYields(); | |
6554 } | |
6555 icms_wait(); | |
6556 | |
6557 // See the comment in coordinator_yield() | |
6558 for (unsigned i = 0; i < CMSYieldSleepCount && | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6559 ConcurrentMarkSweepThread::should_yield() && |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6560 !CMSCollector::foregroundGCIsActive(); ++i) { |
0 | 6561 os::sleep(Thread::current(), 1, false); |
6562 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
6563 } | |
6564 | |
6565 ConcurrentMarkSweepThread::synchronize(true); | |
6566 bitMapLock()->lock_without_safepoint_check(); | |
6567 startTimer(); | |
6568 } | |
6569 curAddr = chunk.end(); | |
6570 } | |
1387
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
6571 // A successful mostly concurrent collection has been done. |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
6572 // Because only the full (i.e., concurrent mode failure) collections |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
6573 // are being measured for gc overhead limits, clean the "near" flag |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
6574 // and count. |
0bfd3fb24150
6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
jmasa
parents:
1289
diff
changeset
|
6575 sp->reset_gc_overhead_limit_count(); |
0 | 6576 _collectorState = Idling; |
6577 } else { | |
6578 // already have the lock | |
6579 assert(_collectorState == Resetting, "just checking"); | |
6580 assert_lock_strong(bitMapLock()); | |
6581 _markBitMap.clear_all(); | |
6582 _collectorState = Idling; | |
6583 } | |
6584 | |
6585 // Stop incremental mode after a cycle completes, so that any future cycles | |
6586 // are triggered by allocation. | |
6587 stop_icms(); | |
6588 | |
6589 NOT_PRODUCT( | |
6590 if (RotateCMSCollectionTypes) { | |
6591 _cmsGen->rotate_debug_collection_type(); | |
6592 } | |
6593 ) | |
10405 | 6594 |
6595 register_gc_end(); | |
0 | 6596 } |
6597 | |
6064
9d679effd28c
7166894: Add gc cause to GC logging for all collectors
brutisso
parents:
6028
diff
changeset
|
6598 void CMSCollector::do_CMS_operation(CMS_op_type op, GCCause::Cause gc_cause) { |
0 | 6599 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); |
6600 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
10405 | 6601 GCTraceTime t(GCCauseString("GC", gc_cause), PrintGC, !PrintGCDetails, NULL); |
0 | 6602 TraceCollectorStats tcs(counters()); |
6603 | |
6604 switch (op) { | |
6605 case CMS_op_checkpointRootsInitial: { | |
2125
7246a374a9f2
6458402: 3 jvmti tests fail with CMS and +ExplicitGCInvokesConcurrent
kamg
parents:
1994
diff
changeset
|
6606 SvcGCMarker sgcm(SvcGCMarker::OTHER); |
0 | 6607 checkpointRootsInitial(true); // asynch |
6608 if (PrintGC) { | |
6609 _cmsGen->printOccupancy("initial-mark"); | |
6610 } | |
6611 break; | |
6612 } | |
6613 case CMS_op_checkpointRootsFinal: { | |
2125
7246a374a9f2
6458402: 3 jvmti tests fail with CMS and +ExplicitGCInvokesConcurrent
kamg
parents:
1994
diff
changeset
|
6614 SvcGCMarker sgcm(SvcGCMarker::OTHER); |
0 | 6615 checkpointRootsFinal(true, // asynch |
6616 false, // !clear_all_soft_refs | |
6617 false); // !init_mark_was_synchronous | |
6618 if (PrintGC) { | |
6619 _cmsGen->printOccupancy("remark"); | |
6620 } | |
6621 break; | |
6622 } | |
6623 default: | |
6624 fatal("No such CMS_op"); | |
6625 } | |
6626 } | |
6627 | |
6628 #ifndef PRODUCT | |
6629 size_t const CMSCollector::skip_header_HeapWords() { | |
6630 return FreeChunk::header_size(); | |
6631 } | |
6632 | |
6633 // Try and collect here conditions that should hold when | |
6634 // CMS thread is exiting. The idea is that the foreground GC | |
6635 // thread should not be blocked if it wants to terminate | |
6636 // the CMS thread and yet continue to run the VM for a while | |
6637 // after that. | |
6638 void CMSCollector::verify_ok_to_terminate() const { | |
6639 assert(Thread::current()->is_ConcurrentGC_thread(), | |
6640 "should be called by CMS thread"); | |
6641 assert(!_foregroundGCShouldWait, "should be false"); | |
6642 // We could check here that all the various low-level locks | |
6643 // are not held by the CMS thread, but that is overkill; see | |
6644 // also CMSThread::verify_ok_to_terminate() where the CGC_lock | |
6645 // is checked. | |
6646 } | |
6647 #endif | |
6648 | |
6649 size_t CMSCollector::block_size_using_printezis_bits(HeapWord* addr) const { | |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
6650 assert(_markBitMap.isMarked(addr) && _markBitMap.isMarked(addr + 1), |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
452
diff
changeset
|
6651 "missing Printezis mark?"); |
0 | 6652 HeapWord* nextOneAddr = _markBitMap.getNextMarkedWordAddress(addr + 2); |
6653 size_t size = pointer_delta(nextOneAddr + 1, addr); | |
6654 assert(size == CompactibleFreeListSpace::adjustObjectSize(size), | |
6655 "alignment problem"); | |
6656 assert(size >= 3, "Necessary for Printezis marks to work"); | |
6657 return size; | |
6658 } | |
6659 | |
6660 // A variant of the above (block_size_using_printezis_bits()) except | |
6661 // that we return 0 if the P-bits are not yet set. | |
6662 size_t CMSCollector::block_size_if_printezis_bits(HeapWord* addr) const { | |
2226
c5a923563727
6912621: iCMS: Error: assert(_markBitMap.isMarked(addr + 1),"Missing Printezis bit?")
ysr
parents:
2177
diff
changeset
|
6663 if (_markBitMap.isMarked(addr + 1)) { |
c5a923563727
6912621: iCMS: Error: assert(_markBitMap.isMarked(addr + 1),"Missing Printezis bit?")
ysr
parents:
2177
diff
changeset
|
6664 assert(_markBitMap.isMarked(addr), "P-bit can be set only for marked objects"); |
0 | 6665 HeapWord* nextOneAddr = _markBitMap.getNextMarkedWordAddress(addr + 2); |
6666 size_t size = pointer_delta(nextOneAddr + 1, addr); | |
6667 assert(size == CompactibleFreeListSpace::adjustObjectSize(size), | |
6668 "alignment problem"); | |
6669 assert(size >= 3, "Necessary for Printezis marks to work"); | |
6670 return size; | |
2226
c5a923563727
6912621: iCMS: Error: assert(_markBitMap.isMarked(addr + 1),"Missing Printezis bit?")
ysr
parents:
2177
diff
changeset
|
6671 } |
c5a923563727
6912621: iCMS: Error: assert(_markBitMap.isMarked(addr + 1),"Missing Printezis bit?")
ysr
parents:
2177
diff
changeset
|
6672 return 0; |
0 | 6673 } |
6674 | |
6675 HeapWord* CMSCollector::next_card_start_after_block(HeapWord* addr) const { | |
6676 size_t sz = 0; | |
6677 oop p = (oop)addr; | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6678 if (p->klass_or_null() != NULL) { |
0 | 6679 sz = CompactibleFreeListSpace::adjustObjectSize(p->size()); |
6680 } else { | |
6681 sz = block_size_using_printezis_bits(addr); | |
6682 } | |
6683 assert(sz > 0, "size must be nonzero"); | |
6684 HeapWord* next_block = addr + sz; | |
6685 HeapWord* next_card = (HeapWord*)round_to((uintptr_t)next_block, | |
6686 CardTableModRefBS::card_size); | |
6687 assert(round_down((uintptr_t)addr, CardTableModRefBS::card_size) < | |
6688 round_down((uintptr_t)next_card, CardTableModRefBS::card_size), | |
6689 "must be different cards"); | |
6690 return next_card; | |
6691 } | |
6692 | |
6693 | |
6694 // CMS Bit Map Wrapper ///////////////////////////////////////// | |
6695 | |
6696 // Construct a CMS bit map infrastructure, but don't create the | |
6697 // bit vector itself. That is done by a separate call CMSBitMap::allocate() | |
6698 // further below. | |
6699 CMSBitMap::CMSBitMap(int shifter, int mutex_rank, const char* mutex_name): | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
6700 _bm(), |
0 | 6701 _shifter(shifter), |
6702 _lock(mutex_rank >= 0 ? new Mutex(mutex_rank, mutex_name, true) : NULL) | |
6703 { | |
6704 _bmStartWord = 0; | |
6705 _bmWordSize = 0; | |
6706 } | |
6707 | |
6708 bool CMSBitMap::allocate(MemRegion mr) { | |
6709 _bmStartWord = mr.start(); | |
6710 _bmWordSize = mr.word_size(); | |
6711 ReservedSpace brs(ReservedSpace::allocation_align_size_up( | |
6712 (_bmWordSize >> (_shifter + LogBitsPerByte)) + 1)); | |
6713 if (!brs.is_reserved()) { | |
6714 warning("CMS bit map allocation failure"); | |
6715 return false; | |
6716 } | |
14309 | 6717 // For now we'll just commit all of the bit map up front. |
0 | 6718 // Later on we'll try to be more parsimonious with swap. |
6719 if (!_virtual_space.initialize(brs, brs.size())) { | |
6720 warning("CMS bit map backing store failure"); | |
6721 return false; | |
6722 } | |
6723 assert(_virtual_space.committed_size() == brs.size(), | |
6724 "didn't reserve backing store for all of CMS bit map?"); | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
6725 _bm.set_map((BitMap::bm_word_t*)_virtual_space.low()); |
0 | 6726 assert(_virtual_space.committed_size() << (_shifter + LogBitsPerByte) >= |
6727 _bmWordSize, "inconsistency in bit map sizing"); | |
6728 _bm.set_size(_bmWordSize >> _shifter); | |
6729 | |
6730 // bm.clear(); // can we rely on getting zero'd memory? verify below | |
6731 assert(isAllClear(), | |
6732 "Expected zero'd memory from ReservedSpace constructor"); | |
6733 assert(_bm.size() == heapWordDiffToOffsetDiff(sizeInWords()), | |
6734 "consistency check"); | |
6735 return true; | |
6736 } | |
6737 | |
6738 void CMSBitMap::dirty_range_iterate_clear(MemRegion mr, MemRegionClosure* cl) { | |
6739 HeapWord *next_addr, *end_addr, *last_addr; | |
6740 assert_locked(); | |
6741 assert(covers(mr), "out-of-range error"); | |
6742 // XXX assert that start and end are appropriately aligned | |
6743 for (next_addr = mr.start(), end_addr = mr.end(); | |
6744 next_addr < end_addr; next_addr = last_addr) { | |
6745 MemRegion dirty_region = getAndClearMarkedRegion(next_addr, end_addr); | |
6746 last_addr = dirty_region.end(); | |
6747 if (!dirty_region.is_empty()) { | |
6748 cl->do_MemRegion(dirty_region); | |
6749 } else { | |
6750 assert(last_addr == end_addr, "program logic"); | |
6751 return; | |
6752 } | |
6753 } | |
6754 } | |
6755 | |
9076
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
6756 void CMSBitMap::print_on_error(outputStream* st, const char* prefix) const { |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
6757 _bm.print_on_error(st, prefix); |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
6758 } |
7b835924c31c
8011872: Include Bit Map addresses in the hs_err files
stefank
parents:
9072
diff
changeset
|
6759 |
0 | 6760 #ifndef PRODUCT |
6761 void CMSBitMap::assert_locked() const { | |
6762 CMSLockVerifier::assert_locked(lock()); | |
6763 } | |
6764 | |
6765 bool CMSBitMap::covers(MemRegion mr) const { | |
6766 // assert(_bm.map() == _virtual_space.low(), "map inconsistency"); | |
6767 assert((size_t)_bm.size() == (_bmWordSize >> _shifter), | |
6768 "size inconsistency"); | |
6769 return (mr.start() >= _bmStartWord) && | |
6770 (mr.end() <= endWord()); | |
6771 } | |
6772 | |
6773 bool CMSBitMap::covers(HeapWord* start, size_t size) const { | |
6774 return (start >= _bmStartWord && (start + size) <= endWord()); | |
6775 } | |
6776 | |
6777 void CMSBitMap::verifyNoOneBitsInRange(HeapWord* left, HeapWord* right) { | |
6778 // verify that there are no 1 bits in the interval [left, right) | |
6779 FalseBitMapClosure falseBitMapClosure; | |
6780 iterate(&falseBitMapClosure, left, right); | |
6781 } | |
6782 | |
6783 void CMSBitMap::region_invariant(MemRegion mr) | |
6784 { | |
6785 assert_locked(); | |
6786 // mr = mr.intersection(MemRegion(_bmStartWord, _bmWordSize)); | |
6787 assert(!mr.is_empty(), "unexpected empty region"); | |
6788 assert(covers(mr), "mr should be covered by bit map"); | |
6789 // convert address range into offset range | |
6790 size_t start_ofs = heapWordToOffset(mr.start()); | |
6791 // Make sure that end() is appropriately aligned | |
6792 assert(mr.end() == (HeapWord*)round_to((intptr_t)mr.end(), | |
6793 (1 << (_shifter+LogHeapWordSize))), | |
6794 "Misaligned mr.end()"); | |
6795 size_t end_ofs = heapWordToOffset(mr.end()); | |
6796 assert(end_ofs > start_ofs, "Should mark at least one bit"); | |
6797 } | |
6798 | |
6799 #endif | |
6800 | |
6801 bool CMSMarkStack::allocate(size_t size) { | |
6802 // allocate a stack of the requisite depth | |
6803 ReservedSpace rs(ReservedSpace::allocation_align_size_up( | |
6804 size * sizeof(oop))); | |
6805 if (!rs.is_reserved()) { | |
6806 warning("CMSMarkStack allocation failure"); | |
6807 return false; | |
6808 } | |
6809 if (!_virtual_space.initialize(rs, rs.size())) { | |
6810 warning("CMSMarkStack backing store failure"); | |
6811 return false; | |
6812 } | |
6813 assert(_virtual_space.committed_size() == rs.size(), | |
6814 "didn't reserve backing store for all of CMS stack?"); | |
6815 _base = (oop*)(_virtual_space.low()); | |
6816 _index = 0; | |
6817 _capacity = size; | |
6818 NOT_PRODUCT(_max_depth = 0); | |
6819 return true; | |
6820 } | |
6821 | |
6822 // XXX FIX ME !!! In the MT case we come in here holding a | |
6823 // leaf lock. For printing we need to take a further lock | |
14309 | 6824 // which has lower rank. We need to recalibrate the two |
6825 // lock-ranks involved in order to be able to print the | |
0 | 6826 // messages below. (Or defer the printing to the caller. |
6827 // For now we take the expedient path of just disabling the | |
6828 // messages for the problematic case.) | |
6829 void CMSMarkStack::expand() { | |
1284 | 6830 assert(_capacity <= MarkStackSizeMax, "stack bigger than permitted"); |
6831 if (_capacity == MarkStackSizeMax) { | |
0 | 6832 if (_hit_limit++ == 0 && !CMSConcurrentMTEnabled && PrintGCDetails) { |
6833 // We print a warning message only once per CMS cycle. | |
6834 gclog_or_tty->print_cr(" (benign) Hit CMSMarkStack max size limit"); | |
6835 } | |
6836 return; | |
6837 } | |
6838 // Double capacity if possible | |
1284 | 6839 size_t new_capacity = MIN2(_capacity*2, MarkStackSizeMax); |
0 | 6840 // Do not give up existing stack until we have managed to |
6841 // get the double capacity that we desired. | |
6842 ReservedSpace rs(ReservedSpace::allocation_align_size_up( | |
6843 new_capacity * sizeof(oop))); | |
6844 if (rs.is_reserved()) { | |
6845 // Release the backing store associated with old stack | |
6846 _virtual_space.release(); | |
6847 // Reinitialize virtual space for new stack | |
6848 if (!_virtual_space.initialize(rs, rs.size())) { | |
6849 fatal("Not enough swap for expanded marking stack"); | |
6850 } | |
6851 _base = (oop*)(_virtual_space.low()); | |
6852 _index = 0; | |
6853 _capacity = new_capacity; | |
6854 } else if (_failed_double++ == 0 && !CMSConcurrentMTEnabled && PrintGCDetails) { | |
6855 // Failed to double capacity, continue; | |
6856 // we print a detail message only once per CMS cycle. | |
6857 gclog_or_tty->print(" (benign) Failed to expand marking stack from "SIZE_FORMAT"K to " | |
6858 SIZE_FORMAT"K", | |
6859 _capacity / K, new_capacity / K); | |
6860 } | |
6861 } | |
6862 | |
6863 | |
6864 // Closures | |
6865 // XXX: there seems to be a lot of code duplication here; | |
6866 // should refactor and consolidate common code. | |
6867 | |
6868 // This closure is used to mark refs into the CMS generation in | |
6869 // the CMS bit map. Called at the first checkpoint. This closure | |
6870 // assumes that we do not need to re-mark dirty cards; if the CMS | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6871 // generation on which this is used is not an oldest |
0 | 6872 // generation then this will lose younger_gen cards! |
6873 | |
6874 MarkRefsIntoClosure::MarkRefsIntoClosure( | |
994
753cf9794df9
6885169: merge of 4957990 and 6863023 causes conflict on do_nmethods
jrose
parents:
993
diff
changeset
|
6875 MemRegion span, CMSBitMap* bitMap): |
0 | 6876 _span(span), |
994
753cf9794df9
6885169: merge of 4957990 and 6863023 causes conflict on do_nmethods
jrose
parents:
993
diff
changeset
|
6877 _bitMap(bitMap) |
0 | 6878 { |
6879 assert(_ref_processor == NULL, "deliberately left NULL"); | |
6880 assert(_bitMap->covers(_span), "_bitMap/_span mismatch"); | |
6881 } | |
6882 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6883 void MarkRefsIntoClosure::do_oop(oop obj) { |
0 | 6884 // if p points into _span, then mark corresponding bit in _markBitMap |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6885 assert(obj->is_oop(), "expected an oop"); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6886 HeapWord* addr = (HeapWord*)obj; |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6887 if (_span.contains(addr)) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6888 // this should be made more efficient |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6889 _bitMap->mark(addr); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6890 } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6891 } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6892 |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6893 void MarkRefsIntoClosure::do_oop(oop* p) { MarkRefsIntoClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6894 void MarkRefsIntoClosure::do_oop(narrowOop* p) { MarkRefsIntoClosure::do_oop_work(p); } |
0 | 6895 |
11975 | 6896 Par_MarkRefsIntoClosure::Par_MarkRefsIntoClosure( |
6897 MemRegion span, CMSBitMap* bitMap): | |
6898 _span(span), | |
6899 _bitMap(bitMap) | |
6900 { | |
6901 assert(_ref_processor == NULL, "deliberately left NULL"); | |
6902 assert(_bitMap->covers(_span), "_bitMap/_span mismatch"); | |
6903 } | |
6904 | |
6905 void Par_MarkRefsIntoClosure::do_oop(oop obj) { | |
6906 // if p points into _span, then mark corresponding bit in _markBitMap | |
6907 assert(obj->is_oop(), "expected an oop"); | |
6908 HeapWord* addr = (HeapWord*)obj; | |
6909 if (_span.contains(addr)) { | |
6910 // this should be made more efficient | |
6911 _bitMap->par_mark(addr); | |
6912 } | |
6913 } | |
6914 | |
6915 void Par_MarkRefsIntoClosure::do_oop(oop* p) { Par_MarkRefsIntoClosure::do_oop_work(p); } | |
6916 void Par_MarkRefsIntoClosure::do_oop(narrowOop* p) { Par_MarkRefsIntoClosure::do_oop_work(p); } | |
6917 | |
0 | 6918 // A variant of the above, used for CMS marking verification. |
6919 MarkRefsIntoVerifyClosure::MarkRefsIntoVerifyClosure( | |
994
753cf9794df9
6885169: merge of 4957990 and 6863023 causes conflict on do_nmethods
jrose
parents:
993
diff
changeset
|
6920 MemRegion span, CMSBitMap* verification_bm, CMSBitMap* cms_bm): |
0 | 6921 _span(span), |
6922 _verification_bm(verification_bm), | |
994
753cf9794df9
6885169: merge of 4957990 and 6863023 causes conflict on do_nmethods
jrose
parents:
993
diff
changeset
|
6923 _cms_bm(cms_bm) |
753cf9794df9
6885169: merge of 4957990 and 6863023 causes conflict on do_nmethods
jrose
parents:
993
diff
changeset
|
6924 { |
0 | 6925 assert(_ref_processor == NULL, "deliberately left NULL"); |
6926 assert(_verification_bm->covers(_span), "_verification_bm/_span mismatch"); | |
6927 } | |
6928 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6929 void MarkRefsIntoVerifyClosure::do_oop(oop obj) { |
0 | 6930 // if p points into _span, then mark corresponding bit in _markBitMap |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6931 assert(obj->is_oop(), "expected an oop"); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6932 HeapWord* addr = (HeapWord*)obj; |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6933 if (_span.contains(addr)) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6934 _verification_bm->mark(addr); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6935 if (!_cms_bm->isMarked(addr)) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6936 oop(addr)->print(); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6937 gclog_or_tty->print_cr(" (" INTPTR_FORMAT " should have been marked)", addr); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6938 fatal("... aborting"); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6939 } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6940 } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6941 } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6942 |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6943 void MarkRefsIntoVerifyClosure::do_oop(oop* p) { MarkRefsIntoVerifyClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6944 void MarkRefsIntoVerifyClosure::do_oop(narrowOop* p) { MarkRefsIntoVerifyClosure::do_oop_work(p); } |
0 | 6945 |
6946 ////////////////////////////////////////////////// | |
6947 // MarkRefsIntoAndScanClosure | |
6948 ////////////////////////////////////////////////// | |
6949 | |
6950 MarkRefsIntoAndScanClosure::MarkRefsIntoAndScanClosure(MemRegion span, | |
6951 ReferenceProcessor* rp, | |
6952 CMSBitMap* bit_map, | |
6953 CMSBitMap* mod_union_table, | |
6954 CMSMarkStack* mark_stack, | |
6955 CMSCollector* collector, | |
6956 bool should_yield, | |
6957 bool concurrent_precleaning): | |
6958 _collector(collector), | |
6959 _span(span), | |
6960 _bit_map(bit_map), | |
6961 _mark_stack(mark_stack), | |
6962 _pushAndMarkClosure(collector, span, rp, bit_map, mod_union_table, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
6963 mark_stack, concurrent_precleaning), |
0 | 6964 _yield(should_yield), |
6965 _concurrent_precleaning(concurrent_precleaning), | |
6966 _freelistLock(NULL) | |
6967 { | |
6968 _ref_processor = rp; | |
6969 assert(_ref_processor != NULL, "_ref_processor shouldn't be NULL"); | |
6970 } | |
6971 | |
6972 // This closure is used to mark refs into the CMS generation at the | |
6973 // second (final) checkpoint, and to scan and transitively follow | |
6974 // the unmarked oops. It is also used during the concurrent precleaning | |
6975 // phase while scanning objects on dirty cards in the CMS generation. | |
6976 // The marks are made in the marking bit map and the marking stack is | |
6977 // used for keeping the (newly) grey objects during the scan. | |
6978 // The parallel version (Par_...) appears further below. | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6979 void MarkRefsIntoAndScanClosure::do_oop(oop obj) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6980 if (obj != NULL) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6981 assert(obj->is_oop(), "expected an oop"); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6982 HeapWord* addr = (HeapWord*)obj; |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6983 assert(_mark_stack->isEmpty(), "pre-condition (eager drainage)"); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6984 assert(_collector->overflow_list_is_empty(), |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6985 "overflow list should be empty"); |
0 | 6986 if (_span.contains(addr) && |
6987 !_bit_map->isMarked(addr)) { | |
6988 // mark bit map (object is now grey) | |
6989 _bit_map->mark(addr); | |
6990 // push on marking stack (stack should be empty), and drain the | |
6991 // stack by applying this closure to the oops in the oops popped | |
6992 // from the stack (i.e. blacken the grey objects) | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
6993 bool res = _mark_stack->push(obj); |
0 | 6994 assert(res, "Should have space to push on empty stack"); |
6995 do { | |
6996 oop new_oop = _mark_stack->pop(); | |
6997 assert(new_oop != NULL && new_oop->is_oop(), "Expected an oop"); | |
6998 assert(_bit_map->isMarked((HeapWord*)new_oop), | |
6999 "only grey objects on this stack"); | |
7000 // iterate over the oops in this oop, marking and pushing | |
7001 // the ones in CMS heap (i.e. in _span). | |
7002 new_oop->oop_iterate(&_pushAndMarkClosure); | |
7003 // check if it's time to yield | |
7004 do_yield_check(); | |
7005 } while (!_mark_stack->isEmpty() || | |
7006 (!_concurrent_precleaning && take_from_overflow_list())); | |
7007 // if marking stack is empty, and we are not doing this | |
7008 // during precleaning, then check the overflow list | |
7009 } | |
7010 assert(_mark_stack->isEmpty(), "post-condition (eager drainage)"); | |
7011 assert(_collector->overflow_list_is_empty(), | |
7012 "overflow list was drained above"); | |
7013 // We could restore evacuated mark words, if any, used for | |
7014 // overflow list links here because the overflow list is | |
7015 // provably empty here. That would reduce the maximum | |
7016 // size requirements for preserved_{oop,mark}_stack. | |
7017 // But we'll just postpone it until we are all done | |
7018 // so we can just stream through. | |
7019 if (!_concurrent_precleaning && CMSOverflowEarlyRestoration) { | |
7020 _collector->restore_preserved_marks_if_any(); | |
7021 assert(_collector->no_preserved_marks(), "No preserved marks"); | |
7022 } | |
7023 assert(!CMSOverflowEarlyRestoration || _collector->no_preserved_marks(), | |
7024 "All preserved marks should have been restored above"); | |
7025 } | |
7026 } | |
7027 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7028 void MarkRefsIntoAndScanClosure::do_oop(oop* p) { MarkRefsIntoAndScanClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7029 void MarkRefsIntoAndScanClosure::do_oop(narrowOop* p) { MarkRefsIntoAndScanClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7030 |
0 | 7031 void MarkRefsIntoAndScanClosure::do_yield_work() { |
7032 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
7033 "CMS thread should hold CMS token"); | |
7034 assert_lock_strong(_freelistLock); | |
7035 assert_lock_strong(_bit_map->lock()); | |
7036 // relinquish the free_list_lock and bitMaplock() | |
7037 _bit_map->lock()->unlock(); | |
7038 _freelistLock->unlock(); | |
7039 ConcurrentMarkSweepThread::desynchronize(true); | |
7040 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
7041 _collector->stopTimer(); | |
7042 GCPauseTimer p(_collector->size_policy()->concurrent_timer_ptr()); | |
7043 if (PrintCMSStatistics != 0) { | |
7044 _collector->incrementYields(); | |
7045 } | |
7046 _collector->icms_wait(); | |
7047 | |
7048 // See the comment in coordinator_yield() | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7049 for (unsigned i = 0; |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7050 i < CMSYieldSleepCount && |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7051 ConcurrentMarkSweepThread::should_yield() && |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7052 !CMSCollector::foregroundGCIsActive(); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7053 ++i) { |
0 | 7054 os::sleep(Thread::current(), 1, false); |
7055 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
7056 } | |
7057 | |
7058 ConcurrentMarkSweepThread::synchronize(true); | |
7059 _freelistLock->lock_without_safepoint_check(); | |
7060 _bit_map->lock()->lock_without_safepoint_check(); | |
7061 _collector->startTimer(); | |
7062 } | |
7063 | |
7064 /////////////////////////////////////////////////////////// | |
7065 // Par_MarkRefsIntoAndScanClosure: a parallel version of | |
7066 // MarkRefsIntoAndScanClosure | |
7067 /////////////////////////////////////////////////////////// | |
7068 Par_MarkRefsIntoAndScanClosure::Par_MarkRefsIntoAndScanClosure( | |
7069 CMSCollector* collector, MemRegion span, ReferenceProcessor* rp, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7070 CMSBitMap* bit_map, OopTaskQueue* work_queue): |
0 | 7071 _span(span), |
7072 _bit_map(bit_map), | |
7073 _work_queue(work_queue), | |
7074 _low_water_mark(MIN2((uint)(work_queue->max_elems()/4), | |
7075 (uint)(CMSWorkQueueDrainThreshold * ParallelGCThreads))), | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7076 _par_pushAndMarkClosure(collector, span, rp, bit_map, work_queue) |
0 | 7077 { |
7078 _ref_processor = rp; | |
7079 assert(_ref_processor != NULL, "_ref_processor shouldn't be NULL"); | |
7080 } | |
7081 | |
7082 // This closure is used to mark refs into the CMS generation at the | |
7083 // second (final) checkpoint, and to scan and transitively follow | |
7084 // the unmarked oops. The marks are made in the marking bit map and | |
7085 // the work_queue is used for keeping the (newly) grey objects during | |
7086 // the scan phase whence they are also available for stealing by parallel | |
7087 // threads. Since the marking bit map is shared, updates are | |
7088 // synchronized (via CAS). | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7089 void Par_MarkRefsIntoAndScanClosure::do_oop(oop obj) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7090 if (obj != NULL) { |
0 | 7091 // Ignore mark word because this could be an already marked oop |
7092 // that may be chained at the end of the overflow list. | |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
7093 assert(obj->is_oop(true), "expected an oop"); |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7094 HeapWord* addr = (HeapWord*)obj; |
0 | 7095 if (_span.contains(addr) && |
7096 !_bit_map->isMarked(addr)) { | |
7097 // mark bit map (object will become grey): | |
7098 // It is possible for several threads to be | |
7099 // trying to "claim" this object concurrently; | |
7100 // the unique thread that succeeds in marking the | |
7101 // object first will do the subsequent push on | |
7102 // to the work queue (or overflow list). | |
7103 if (_bit_map->par_mark(addr)) { | |
7104 // push on work_queue (which may not be empty), and trim the | |
7105 // queue to an appropriate length by applying this closure to | |
7106 // the oops in the oops popped from the stack (i.e. blacken the | |
7107 // grey objects) | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7108 bool res = _work_queue->push(obj); |
0 | 7109 assert(res, "Low water mark should be less than capacity?"); |
7110 trim_queue(_low_water_mark); | |
7111 } // Else, another thread claimed the object | |
7112 } | |
7113 } | |
7114 } | |
7115 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7116 void Par_MarkRefsIntoAndScanClosure::do_oop(oop* p) { Par_MarkRefsIntoAndScanClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7117 void Par_MarkRefsIntoAndScanClosure::do_oop(narrowOop* p) { Par_MarkRefsIntoAndScanClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7118 |
0 | 7119 // This closure is used to rescan the marked objects on the dirty cards |
7120 // in the mod union table and the card table proper. | |
7121 size_t ScanMarkedObjectsAgainCarefullyClosure::do_object_careful_m( | |
7122 oop p, MemRegion mr) { | |
7123 | |
7124 size_t size = 0; | |
7125 HeapWord* addr = (HeapWord*)p; | |
7126 DEBUG_ONLY(_collector->verify_work_stacks_empty();) | |
7127 assert(_span.contains(addr), "we are scanning the CMS generation"); | |
7128 // check if it's time to yield | |
7129 if (do_yield_check()) { | |
7130 // We yielded for some foreground stop-world work, | |
7131 // and we have been asked to abort this ongoing preclean cycle. | |
7132 return 0; | |
7133 } | |
7134 if (_bitMap->isMarked(addr)) { | |
7135 // it's marked; is it potentially uninitialized? | |
187 | 7136 if (p->klass_or_null() != NULL) { |
0 | 7137 // an initialized object; ignore mark word in verification below |
7138 // since we are running concurrent with mutators | |
7139 assert(p->is_oop(true), "should be an oop"); | |
7140 if (p->is_objArray()) { | |
7141 // objArrays are precisely marked; restrict scanning | |
7142 // to dirty cards only. | |
187 | 7143 size = CompactibleFreeListSpace::adjustObjectSize( |
7144 p->oop_iterate(_scanningClosure, mr)); | |
0 | 7145 } else { |
7146 // A non-array may have been imprecisely marked; we need | |
7147 // to scan object in its entirety. | |
7148 size = CompactibleFreeListSpace::adjustObjectSize( | |
7149 p->oop_iterate(_scanningClosure)); | |
7150 } | |
9152 | 7151 #ifdef ASSERT |
0 | 7152 size_t direct_size = |
7153 CompactibleFreeListSpace::adjustObjectSize(p->size()); | |
7154 assert(size == direct_size, "Inconsistency in size"); | |
7155 assert(size >= 3, "Necessary for Printezis marks to work"); | |
7156 if (!_bitMap->isMarked(addr+1)) { | |
7157 _bitMap->verifyNoOneBitsInRange(addr+2, addr+size); | |
7158 } else { | |
7159 _bitMap->verifyNoOneBitsInRange(addr+2, addr+size-1); | |
7160 assert(_bitMap->isMarked(addr+size-1), | |
7161 "inconsistent Printezis mark"); | |
7162 } | |
9152 | 7163 #endif // ASSERT |
0 | 7164 } else { |
14309 | 7165 // An uninitialized object. |
0 | 7166 assert(_bitMap->isMarked(addr+1), "missing Printezis mark?"); |
7167 HeapWord* nextOneAddr = _bitMap->getNextMarkedWordAddress(addr + 2); | |
7168 size = pointer_delta(nextOneAddr + 1, addr); | |
7169 assert(size == CompactibleFreeListSpace::adjustObjectSize(size), | |
7170 "alignment problem"); | |
7171 // Note that pre-cleaning needn't redirty the card. OopDesc::set_klass() | |
7172 // will dirty the card when the klass pointer is installed in the | |
14309 | 7173 // object (signaling the completion of initialization). |
0 | 7174 } |
7175 } else { | |
7176 // Either a not yet marked object or an uninitialized object | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7177 if (p->klass_or_null() == NULL) { |
0 | 7178 // An uninitialized object, skip to the next card, since |
7179 // we may not be able to read its P-bits yet. | |
7180 assert(size == 0, "Initial value"); | |
7181 } else { | |
7182 // An object not (yet) reached by marking: we merely need to | |
7183 // compute its size so as to go look at the next block. | |
7184 assert(p->is_oop(true), "should be an oop"); | |
7185 size = CompactibleFreeListSpace::adjustObjectSize(p->size()); | |
7186 } | |
7187 } | |
7188 DEBUG_ONLY(_collector->verify_work_stacks_empty();) | |
7189 return size; | |
7190 } | |
7191 | |
7192 void ScanMarkedObjectsAgainCarefullyClosure::do_yield_work() { | |
7193 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
7194 "CMS thread should hold CMS token"); | |
7195 assert_lock_strong(_freelistLock); | |
7196 assert_lock_strong(_bitMap->lock()); | |
7197 // relinquish the free_list_lock and bitMaplock() | |
7198 _bitMap->lock()->unlock(); | |
7199 _freelistLock->unlock(); | |
7200 ConcurrentMarkSweepThread::desynchronize(true); | |
7201 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
7202 _collector->stopTimer(); | |
7203 GCPauseTimer p(_collector->size_policy()->concurrent_timer_ptr()); | |
7204 if (PrintCMSStatistics != 0) { | |
7205 _collector->incrementYields(); | |
7206 } | |
7207 _collector->icms_wait(); | |
7208 | |
7209 // See the comment in coordinator_yield() | |
7210 for (unsigned i = 0; i < CMSYieldSleepCount && | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7211 ConcurrentMarkSweepThread::should_yield() && |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7212 !CMSCollector::foregroundGCIsActive(); ++i) { |
0 | 7213 os::sleep(Thread::current(), 1, false); |
7214 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
7215 } | |
7216 | |
7217 ConcurrentMarkSweepThread::synchronize(true); | |
7218 _freelistLock->lock_without_safepoint_check(); | |
7219 _bitMap->lock()->lock_without_safepoint_check(); | |
7220 _collector->startTimer(); | |
7221 } | |
7222 | |
7223 | |
7224 ////////////////////////////////////////////////////////////////// | |
7225 // SurvivorSpacePrecleanClosure | |
7226 ////////////////////////////////////////////////////////////////// | |
7227 // This (single-threaded) closure is used to preclean the oops in | |
7228 // the survivor spaces. | |
7229 size_t SurvivorSpacePrecleanClosure::do_object_careful(oop p) { | |
7230 | |
7231 HeapWord* addr = (HeapWord*)p; | |
7232 DEBUG_ONLY(_collector->verify_work_stacks_empty();) | |
7233 assert(!_span.contains(addr), "we are scanning the survivor spaces"); | |
14358 | 7234 assert(p->klass_or_null() != NULL, "object should be initialized"); |
0 | 7235 // an initialized object; ignore mark word in verification below |
7236 // since we are running concurrent with mutators | |
7237 assert(p->is_oop(true), "should be an oop"); | |
7238 // Note that we do not yield while we iterate over | |
7239 // the interior oops of p, pushing the relevant ones | |
7240 // on our marking stack. | |
7241 size_t size = p->oop_iterate(_scanning_closure); | |
7242 do_yield_check(); | |
7243 // Observe that below, we do not abandon the preclean | |
7244 // phase as soon as we should; rather we empty the | |
7245 // marking stack before returning. This is to satisfy | |
7246 // some existing assertions. In general, it may be a | |
7247 // good idea to abort immediately and complete the marking | |
7248 // from the grey objects at a later time. | |
7249 while (!_mark_stack->isEmpty()) { | |
7250 oop new_oop = _mark_stack->pop(); | |
7251 assert(new_oop != NULL && new_oop->is_oop(), "Expected an oop"); | |
7252 assert(_bit_map->isMarked((HeapWord*)new_oop), | |
7253 "only grey objects on this stack"); | |
7254 // iterate over the oops in this oop, marking and pushing | |
7255 // the ones in CMS heap (i.e. in _span). | |
7256 new_oop->oop_iterate(_scanning_closure); | |
7257 // check if it's time to yield | |
7258 do_yield_check(); | |
7259 } | |
7260 unsigned int after_count = | |
7261 GenCollectedHeap::heap()->total_collections(); | |
7262 bool abort = (_before_count != after_count) || | |
7263 _collector->should_abort_preclean(); | |
7264 return abort ? 0 : size; | |
7265 } | |
7266 | |
7267 void SurvivorSpacePrecleanClosure::do_yield_work() { | |
7268 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
7269 "CMS thread should hold CMS token"); | |
7270 assert_lock_strong(_bit_map->lock()); | |
7271 // Relinquish the bit map lock | |
7272 _bit_map->lock()->unlock(); | |
7273 ConcurrentMarkSweepThread::desynchronize(true); | |
7274 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
7275 _collector->stopTimer(); | |
7276 GCPauseTimer p(_collector->size_policy()->concurrent_timer_ptr()); | |
7277 if (PrintCMSStatistics != 0) { | |
7278 _collector->incrementYields(); | |
7279 } | |
7280 _collector->icms_wait(); | |
7281 | |
7282 // See the comment in coordinator_yield() | |
7283 for (unsigned i = 0; i < CMSYieldSleepCount && | |
7284 ConcurrentMarkSweepThread::should_yield() && | |
7285 !CMSCollector::foregroundGCIsActive(); ++i) { | |
7286 os::sleep(Thread::current(), 1, false); | |
7287 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
7288 } | |
7289 | |
7290 ConcurrentMarkSweepThread::synchronize(true); | |
7291 _bit_map->lock()->lock_without_safepoint_check(); | |
7292 _collector->startTimer(); | |
7293 } | |
7294 | |
7295 // This closure is used to rescan the marked objects on the dirty cards | |
7296 // in the mod union table and the card table proper. In the parallel | |
7297 // case, although the bitMap is shared, we do a single read so the | |
7298 // isMarked() query is "safe". | |
7299 bool ScanMarkedObjectsAgainClosure::do_object_bm(oop p, MemRegion mr) { | |
7300 // Ignore mark word because we are running concurrent with mutators | |
7301 assert(p->is_oop_or_null(true), "expected an oop or null"); | |
7302 HeapWord* addr = (HeapWord*)p; | |
7303 assert(_span.contains(addr), "we are scanning the CMS generation"); | |
7304 bool is_obj_array = false; | |
9152 | 7305 #ifdef ASSERT |
0 | 7306 if (!_parallel) { |
7307 assert(_mark_stack->isEmpty(), "pre-condition (eager drainage)"); | |
7308 assert(_collector->overflow_list_is_empty(), | |
7309 "overflow list should be empty"); | |
7310 | |
7311 } | |
9152 | 7312 #endif // ASSERT |
0 | 7313 if (_bit_map->isMarked(addr)) { |
7314 // Obj arrays are precisely marked, non-arrays are not; | |
7315 // so we scan objArrays precisely and non-arrays in their | |
7316 // entirety. | |
7317 if (p->is_objArray()) { | |
7318 is_obj_array = true; | |
7319 if (_parallel) { | |
7320 p->oop_iterate(_par_scan_closure, mr); | |
7321 } else { | |
7322 p->oop_iterate(_scan_closure, mr); | |
7323 } | |
7324 } else { | |
7325 if (_parallel) { | |
7326 p->oop_iterate(_par_scan_closure); | |
7327 } else { | |
7328 p->oop_iterate(_scan_closure); | |
7329 } | |
7330 } | |
7331 } | |
9152 | 7332 #ifdef ASSERT |
0 | 7333 if (!_parallel) { |
7334 assert(_mark_stack->isEmpty(), "post-condition (eager drainage)"); | |
7335 assert(_collector->overflow_list_is_empty(), | |
7336 "overflow list should be empty"); | |
7337 | |
7338 } | |
9152 | 7339 #endif // ASSERT |
0 | 7340 return is_obj_array; |
7341 } | |
7342 | |
7343 MarkFromRootsClosure::MarkFromRootsClosure(CMSCollector* collector, | |
7344 MemRegion span, | |
7345 CMSBitMap* bitMap, CMSMarkStack* markStack, | |
7346 bool should_yield, bool verifying): | |
7347 _collector(collector), | |
7348 _span(span), | |
7349 _bitMap(bitMap), | |
7350 _mut(&collector->_modUnionTable), | |
7351 _markStack(markStack), | |
7352 _yield(should_yield), | |
7353 _skipBits(0) | |
7354 { | |
7355 assert(_markStack->isEmpty(), "stack should be empty"); | |
7356 _finger = _bitMap->startWord(); | |
7357 _threshold = _finger; | |
7358 assert(_collector->_restart_addr == NULL, "Sanity check"); | |
7359 assert(_span.contains(_finger), "Out of bounds _finger?"); | |
7360 DEBUG_ONLY(_verifying = verifying;) | |
7361 } | |
7362 | |
7363 void MarkFromRootsClosure::reset(HeapWord* addr) { | |
7364 assert(_markStack->isEmpty(), "would cause duplicates on stack"); | |
7365 assert(_span.contains(addr), "Out of bounds _finger?"); | |
7366 _finger = addr; | |
7367 _threshold = (HeapWord*)round_to( | |
7368 (intptr_t)_finger, CardTableModRefBS::card_size); | |
7369 } | |
7370 | |
7371 // Should revisit to see if this should be restructured for | |
7372 // greater efficiency. | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7373 bool MarkFromRootsClosure::do_bit(size_t offset) { |
0 | 7374 if (_skipBits > 0) { |
7375 _skipBits--; | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7376 return true; |
0 | 7377 } |
7378 // convert offset into a HeapWord* | |
7379 HeapWord* addr = _bitMap->startWord() + offset; | |
7380 assert(_bitMap->endWord() && addr < _bitMap->endWord(), | |
7381 "address out of range"); | |
7382 assert(_bitMap->isMarked(addr), "tautology"); | |
7383 if (_bitMap->isMarked(addr+1)) { | |
7384 // this is an allocated but not yet initialized object | |
7385 assert(_skipBits == 0, "tautology"); | |
7386 _skipBits = 2; // skip next two marked bits ("Printezis-marks") | |
7387 oop p = oop(addr); | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7388 if (p->klass_or_null() == NULL) { |
0 | 7389 DEBUG_ONLY(if (!_verifying) {) |
7390 // We re-dirty the cards on which this object lies and increase | |
7391 // the _threshold so that we'll come back to scan this object | |
7392 // during the preclean or remark phase. (CMSCleanOnEnter) | |
7393 if (CMSCleanOnEnter) { | |
7394 size_t sz = _collector->block_size_using_printezis_bits(addr); | |
7395 HeapWord* end_card_addr = (HeapWord*)round_to( | |
7396 (intptr_t)(addr+sz), CardTableModRefBS::card_size); | |
283
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7397 MemRegion redirty_range = MemRegion(addr, end_card_addr); |
0 | 7398 assert(!redirty_range.is_empty(), "Arithmetical tautology"); |
7399 // Bump _threshold to end_card_addr; note that | |
7400 // _threshold cannot possibly exceed end_card_addr, anyhow. | |
7401 // This prevents future clearing of the card as the scan proceeds | |
7402 // to the right. | |
7403 assert(_threshold <= end_card_addr, | |
7404 "Because we are just scanning into this object"); | |
7405 if (_threshold < end_card_addr) { | |
7406 _threshold = end_card_addr; | |
7407 } | |
187 | 7408 if (p->klass_or_null() != NULL) { |
0 | 7409 // Redirty the range of cards... |
7410 _mut->mark_range(redirty_range); | |
7411 } // ...else the setting of klass will dirty the card anyway. | |
7412 } | |
7413 DEBUG_ONLY(}) | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7414 return true; |
0 | 7415 } |
7416 } | |
7417 scanOopsInOop(addr); | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7418 return true; |
0 | 7419 } |
7420 | |
7421 // We take a break if we've been at this for a while, | |
7422 // so as to avoid monopolizing the locks involved. | |
7423 void MarkFromRootsClosure::do_yield_work() { | |
7424 // First give up the locks, then yield, then re-lock | |
7425 // We should probably use a constructor/destructor idiom to | |
7426 // do this unlock/lock or modify the MutexUnlocker class to | |
7427 // serve our purpose. XXX | |
7428 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
7429 "CMS thread should hold CMS token"); | |
7430 assert_lock_strong(_bitMap->lock()); | |
7431 _bitMap->lock()->unlock(); | |
7432 ConcurrentMarkSweepThread::desynchronize(true); | |
7433 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
7434 _collector->stopTimer(); | |
7435 GCPauseTimer p(_collector->size_policy()->concurrent_timer_ptr()); | |
7436 if (PrintCMSStatistics != 0) { | |
7437 _collector->incrementYields(); | |
7438 } | |
7439 _collector->icms_wait(); | |
7440 | |
7441 // See the comment in coordinator_yield() | |
7442 for (unsigned i = 0; i < CMSYieldSleepCount && | |
7443 ConcurrentMarkSweepThread::should_yield() && | |
7444 !CMSCollector::foregroundGCIsActive(); ++i) { | |
7445 os::sleep(Thread::current(), 1, false); | |
7446 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
7447 } | |
7448 | |
7449 ConcurrentMarkSweepThread::synchronize(true); | |
7450 _bitMap->lock()->lock_without_safepoint_check(); | |
7451 _collector->startTimer(); | |
7452 } | |
7453 | |
7454 void MarkFromRootsClosure::scanOopsInOop(HeapWord* ptr) { | |
7455 assert(_bitMap->isMarked(ptr), "expected bit to be set"); | |
7456 assert(_markStack->isEmpty(), | |
7457 "should drain stack to limit stack usage"); | |
7458 // convert ptr to an oop preparatory to scanning | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7459 oop obj = oop(ptr); |
0 | 7460 // Ignore mark word in verification below, since we |
7461 // may be running concurrent with mutators. | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7462 assert(obj->is_oop(true), "should be an oop"); |
0 | 7463 assert(_finger <= ptr, "_finger runneth ahead"); |
7464 // advance the finger to right end of this object | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7465 _finger = ptr + obj->size(); |
0 | 7466 assert(_finger > ptr, "we just incremented it above"); |
7467 // On large heaps, it may take us some time to get through | |
7468 // the marking phase (especially if running iCMS). During | |
7469 // this time it's possible that a lot of mutations have | |
7470 // accumulated in the card table and the mod union table -- | |
7471 // these mutation records are redundant until we have | |
7472 // actually traced into the corresponding card. | |
7473 // Here, we check whether advancing the finger would make | |
7474 // us cross into a new card, and if so clear corresponding | |
7475 // cards in the MUT (preclean them in the card-table in the | |
7476 // future). | |
7477 | |
7478 DEBUG_ONLY(if (!_verifying) {) | |
7479 // The clean-on-enter optimization is disabled by default, | |
7480 // until we fix 6178663. | |
7481 if (CMSCleanOnEnter && (_finger > _threshold)) { | |
7482 // [_threshold, _finger) represents the interval | |
7483 // of cards to be cleared in MUT (or precleaned in card table). | |
7484 // The set of cards to be cleared is all those that overlap | |
7485 // with the interval [_threshold, _finger); note that | |
7486 // _threshold is always kept card-aligned but _finger isn't | |
7487 // always card-aligned. | |
7488 HeapWord* old_threshold = _threshold; | |
7489 assert(old_threshold == (HeapWord*)round_to( | |
7490 (intptr_t)old_threshold, CardTableModRefBS::card_size), | |
7491 "_threshold should always be card-aligned"); | |
7492 _threshold = (HeapWord*)round_to( | |
7493 (intptr_t)_finger, CardTableModRefBS::card_size); | |
7494 MemRegion mr(old_threshold, _threshold); | |
7495 assert(!mr.is_empty(), "Control point invariant"); | |
7496 assert(_span.contains(mr), "Should clear within span"); | |
7497 _mut->clear_range(mr); | |
7498 } | |
7499 DEBUG_ONLY(}) | |
7500 // Note: the finger doesn't advance while we drain | |
7501 // the stack below. | |
7502 PushOrMarkClosure pushOrMarkClosure(_collector, | |
7503 _span, _bitMap, _markStack, | |
7504 _finger, this); | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7505 bool res = _markStack->push(obj); |
0 | 7506 assert(res, "Empty non-zero size stack should have space for single push"); |
7507 while (!_markStack->isEmpty()) { | |
7508 oop new_oop = _markStack->pop(); | |
7509 // Skip verifying header mark word below because we are | |
7510 // running concurrent with mutators. | |
7511 assert(new_oop->is_oop(true), "Oops! expected to pop an oop"); | |
7512 // now scan this oop's oops | |
7513 new_oop->oop_iterate(&pushOrMarkClosure); | |
7514 do_yield_check(); | |
7515 } | |
7516 assert(_markStack->isEmpty(), "tautology, emphasizing post-condition"); | |
7517 } | |
7518 | |
7519 Par_MarkFromRootsClosure::Par_MarkFromRootsClosure(CMSConcMarkingTask* task, | |
7520 CMSCollector* collector, MemRegion span, | |
7521 CMSBitMap* bit_map, | |
7522 OopTaskQueue* work_queue, | |
7523 CMSMarkStack* overflow_stack, | |
7524 bool should_yield): | |
7525 _collector(collector), | |
7526 _whole_span(collector->_span), | |
7527 _span(span), | |
7528 _bit_map(bit_map), | |
7529 _mut(&collector->_modUnionTable), | |
7530 _work_queue(work_queue), | |
7531 _overflow_stack(overflow_stack), | |
7532 _yield(should_yield), | |
7533 _skip_bits(0), | |
7534 _task(task) | |
7535 { | |
7536 assert(_work_queue->size() == 0, "work_queue should be empty"); | |
7537 _finger = span.start(); | |
7538 _threshold = _finger; // XXX Defer clear-on-enter optimization for now | |
7539 assert(_span.contains(_finger), "Out of bounds _finger?"); | |
7540 } | |
7541 | |
7542 // Should revisit to see if this should be restructured for | |
7543 // greater efficiency. | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7544 bool Par_MarkFromRootsClosure::do_bit(size_t offset) { |
0 | 7545 if (_skip_bits > 0) { |
7546 _skip_bits--; | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7547 return true; |
0 | 7548 } |
7549 // convert offset into a HeapWord* | |
7550 HeapWord* addr = _bit_map->startWord() + offset; | |
7551 assert(_bit_map->endWord() && addr < _bit_map->endWord(), | |
7552 "address out of range"); | |
7553 assert(_bit_map->isMarked(addr), "tautology"); | |
7554 if (_bit_map->isMarked(addr+1)) { | |
7555 // this is an allocated object that might not yet be initialized | |
7556 assert(_skip_bits == 0, "tautology"); | |
7557 _skip_bits = 2; // skip next two marked bits ("Printezis-marks") | |
7558 oop p = oop(addr); | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7559 if (p->klass_or_null() == NULL) { |
0 | 7560 // in the case of Clean-on-Enter optimization, redirty card |
7561 // and avoid clearing card by increasing the threshold. | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7562 return true; |
0 | 7563 } |
7564 } | |
7565 scan_oops_in_oop(addr); | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7566 return true; |
0 | 7567 } |
7568 | |
7569 void Par_MarkFromRootsClosure::scan_oops_in_oop(HeapWord* ptr) { | |
7570 assert(_bit_map->isMarked(ptr), "expected bit to be set"); | |
7571 // Should we assert that our work queue is empty or | |
7572 // below some drain limit? | |
7573 assert(_work_queue->size() == 0, | |
7574 "should drain stack to limit stack usage"); | |
7575 // convert ptr to an oop preparatory to scanning | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7576 oop obj = oop(ptr); |
0 | 7577 // Ignore mark word in verification below, since we |
7578 // may be running concurrent with mutators. | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7579 assert(obj->is_oop(true), "should be an oop"); |
0 | 7580 assert(_finger <= ptr, "_finger runneth ahead"); |
7581 // advance the finger to right end of this object | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7582 _finger = ptr + obj->size(); |
0 | 7583 assert(_finger > ptr, "we just incremented it above"); |
7584 // On large heaps, it may take us some time to get through | |
7585 // the marking phase (especially if running iCMS). During | |
7586 // this time it's possible that a lot of mutations have | |
7587 // accumulated in the card table and the mod union table -- | |
7588 // these mutation records are redundant until we have | |
7589 // actually traced into the corresponding card. | |
7590 // Here, we check whether advancing the finger would make | |
7591 // us cross into a new card, and if so clear corresponding | |
7592 // cards in the MUT (preclean them in the card-table in the | |
7593 // future). | |
7594 | |
7595 // The clean-on-enter optimization is disabled by default, | |
7596 // until we fix 6178663. | |
7597 if (CMSCleanOnEnter && (_finger > _threshold)) { | |
7598 // [_threshold, _finger) represents the interval | |
7599 // of cards to be cleared in MUT (or precleaned in card table). | |
7600 // The set of cards to be cleared is all those that overlap | |
7601 // with the interval [_threshold, _finger); note that | |
7602 // _threshold is always kept card-aligned but _finger isn't | |
7603 // always card-aligned. | |
7604 HeapWord* old_threshold = _threshold; | |
7605 assert(old_threshold == (HeapWord*)round_to( | |
7606 (intptr_t)old_threshold, CardTableModRefBS::card_size), | |
7607 "_threshold should always be card-aligned"); | |
7608 _threshold = (HeapWord*)round_to( | |
7609 (intptr_t)_finger, CardTableModRefBS::card_size); | |
7610 MemRegion mr(old_threshold, _threshold); | |
7611 assert(!mr.is_empty(), "Control point invariant"); | |
7612 assert(_span.contains(mr), "Should clear within span"); // _whole_span ?? | |
7613 _mut->clear_range(mr); | |
7614 } | |
7615 | |
7616 // Note: the local finger doesn't advance while we drain | |
7617 // the stack below, but the global finger sure can and will. | |
7618 HeapWord** gfa = _task->global_finger_addr(); | |
7619 Par_PushOrMarkClosure pushOrMarkClosure(_collector, | |
7620 _span, _bit_map, | |
7621 _work_queue, | |
7622 _overflow_stack, | |
7623 _finger, | |
7624 gfa, this); | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7625 bool res = _work_queue->push(obj); // overflow could occur here |
0 | 7626 assert(res, "Will hold once we use workqueues"); |
7627 while (true) { | |
7628 oop new_oop; | |
7629 if (!_work_queue->pop_local(new_oop)) { | |
7630 // We emptied our work_queue; check if there's stuff that can | |
7631 // be gotten from the overflow stack. | |
7632 if (CMSConcMarkingTask::get_work_from_overflow_stack( | |
7633 _overflow_stack, _work_queue)) { | |
7634 do_yield_check(); | |
7635 continue; | |
7636 } else { // done | |
7637 break; | |
7638 } | |
7639 } | |
7640 // Skip verifying header mark word below because we are | |
7641 // running concurrent with mutators. | |
7642 assert(new_oop->is_oop(true), "Oops! expected to pop an oop"); | |
7643 // now scan this oop's oops | |
7644 new_oop->oop_iterate(&pushOrMarkClosure); | |
7645 do_yield_check(); | |
7646 } | |
7647 assert(_work_queue->size() == 0, "tautology, emphasizing post-condition"); | |
7648 } | |
7649 | |
7650 // Yield in response to a request from VM Thread or | |
7651 // from mutators. | |
7652 void Par_MarkFromRootsClosure::do_yield_work() { | |
7653 assert(_task != NULL, "sanity"); | |
7654 _task->yield(); | |
7655 } | |
7656 | |
7657 // A variant of the above used for verifying CMS marking work. | |
7658 MarkFromRootsVerifyClosure::MarkFromRootsVerifyClosure(CMSCollector* collector, | |
7659 MemRegion span, | |
7660 CMSBitMap* verification_bm, CMSBitMap* cms_bm, | |
7661 CMSMarkStack* mark_stack): | |
7662 _collector(collector), | |
7663 _span(span), | |
7664 _verification_bm(verification_bm), | |
7665 _cms_bm(cms_bm), | |
7666 _mark_stack(mark_stack), | |
7667 _pam_verify_closure(collector, span, verification_bm, cms_bm, | |
7668 mark_stack) | |
7669 { | |
7670 assert(_mark_stack->isEmpty(), "stack should be empty"); | |
7671 _finger = _verification_bm->startWord(); | |
7672 assert(_collector->_restart_addr == NULL, "Sanity check"); | |
7673 assert(_span.contains(_finger), "Out of bounds _finger?"); | |
7674 } | |
7675 | |
7676 void MarkFromRootsVerifyClosure::reset(HeapWord* addr) { | |
7677 assert(_mark_stack->isEmpty(), "would cause duplicates on stack"); | |
7678 assert(_span.contains(addr), "Out of bounds _finger?"); | |
7679 _finger = addr; | |
7680 } | |
7681 | |
7682 // Should revisit to see if this should be restructured for | |
7683 // greater efficiency. | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7684 bool MarkFromRootsVerifyClosure::do_bit(size_t offset) { |
0 | 7685 // convert offset into a HeapWord* |
7686 HeapWord* addr = _verification_bm->startWord() + offset; | |
7687 assert(_verification_bm->endWord() && addr < _verification_bm->endWord(), | |
7688 "address out of range"); | |
7689 assert(_verification_bm->isMarked(addr), "tautology"); | |
7690 assert(_cms_bm->isMarked(addr), "tautology"); | |
7691 | |
7692 assert(_mark_stack->isEmpty(), | |
7693 "should drain stack to limit stack usage"); | |
7694 // convert addr to an oop preparatory to scanning | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7695 oop obj = oop(addr); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7696 assert(obj->is_oop(), "should be an oop"); |
0 | 7697 assert(_finger <= addr, "_finger runneth ahead"); |
7698 // advance the finger to right end of this object | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7699 _finger = addr + obj->size(); |
0 | 7700 assert(_finger > addr, "we just incremented it above"); |
7701 // Note: the finger doesn't advance while we drain | |
7702 // the stack below. | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7703 bool res = _mark_stack->push(obj); |
0 | 7704 assert(res, "Empty non-zero size stack should have space for single push"); |
7705 while (!_mark_stack->isEmpty()) { | |
7706 oop new_oop = _mark_stack->pop(); | |
7707 assert(new_oop->is_oop(), "Oops! expected to pop an oop"); | |
7708 // now scan this oop's oops | |
7709 new_oop->oop_iterate(&_pam_verify_closure); | |
7710 } | |
7711 assert(_mark_stack->isEmpty(), "tautology, emphasizing post-condition"); | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7712 return true; |
0 | 7713 } |
7714 | |
7715 PushAndMarkVerifyClosure::PushAndMarkVerifyClosure( | |
7716 CMSCollector* collector, MemRegion span, | |
7717 CMSBitMap* verification_bm, CMSBitMap* cms_bm, | |
7718 CMSMarkStack* mark_stack): | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7719 CMSOopClosure(collector->ref_processor()), |
0 | 7720 _collector(collector), |
7721 _span(span), | |
7722 _verification_bm(verification_bm), | |
7723 _cms_bm(cms_bm), | |
7724 _mark_stack(mark_stack) | |
7725 { } | |
7726 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7727 void PushAndMarkVerifyClosure::do_oop(oop* p) { PushAndMarkVerifyClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7728 void PushAndMarkVerifyClosure::do_oop(narrowOop* p) { PushAndMarkVerifyClosure::do_oop_work(p); } |
0 | 7729 |
7730 // Upon stack overflow, we discard (part of) the stack, | |
7731 // remembering the least address amongst those discarded | |
7732 // in CMSCollector's _restart_address. | |
7733 void PushAndMarkVerifyClosure::handle_stack_overflow(HeapWord* lost) { | |
7734 // Remember the least grey address discarded | |
7735 HeapWord* ra = (HeapWord*)_mark_stack->least_value(lost); | |
7736 _collector->lower_restart_addr(ra); | |
7737 _mark_stack->reset(); // discard stack contents | |
7738 _mark_stack->expand(); // expand the stack if possible | |
7739 } | |
7740 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7741 void PushAndMarkVerifyClosure::do_oop(oop obj) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7742 assert(obj->is_oop_or_null(), "expected an oop or NULL"); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7743 HeapWord* addr = (HeapWord*)obj; |
0 | 7744 if (_span.contains(addr) && !_verification_bm->isMarked(addr)) { |
7745 // Oop lies in _span and isn't yet grey or black | |
7746 _verification_bm->mark(addr); // now grey | |
7747 if (!_cms_bm->isMarked(addr)) { | |
7748 oop(addr)->print(); | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7749 gclog_or_tty->print_cr(" (" INTPTR_FORMAT " should have been marked)", |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7750 addr); |
0 | 7751 fatal("... aborting"); |
7752 } | |
7753 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7754 if (!_mark_stack->push(obj)) { // stack overflow |
0 | 7755 if (PrintCMSStatistics != 0) { |
7756 gclog_or_tty->print_cr("CMS marking stack overflow (benign) at " | |
7757 SIZE_FORMAT, _mark_stack->capacity()); | |
7758 } | |
7759 assert(_mark_stack->isFull(), "Else push should have succeeded"); | |
7760 handle_stack_overflow(addr); | |
7761 } | |
7762 // anything including and to the right of _finger | |
7763 // will be scanned as we iterate over the remainder of the | |
7764 // bit map | |
7765 } | |
7766 } | |
7767 | |
7768 PushOrMarkClosure::PushOrMarkClosure(CMSCollector* collector, | |
7769 MemRegion span, | |
7770 CMSBitMap* bitMap, CMSMarkStack* markStack, | |
7771 HeapWord* finger, MarkFromRootsClosure* parent) : | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7772 CMSOopClosure(collector->ref_processor()), |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7773 _collector(collector), |
0 | 7774 _span(span), |
7775 _bitMap(bitMap), | |
7776 _markStack(markStack), | |
7777 _finger(finger), | |
935 | 7778 _parent(parent) |
0 | 7779 { } |
7780 | |
7781 Par_PushOrMarkClosure::Par_PushOrMarkClosure(CMSCollector* collector, | |
7782 MemRegion span, | |
7783 CMSBitMap* bit_map, | |
7784 OopTaskQueue* work_queue, | |
7785 CMSMarkStack* overflow_stack, | |
7786 HeapWord* finger, | |
7787 HeapWord** global_finger_addr, | |
7788 Par_MarkFromRootsClosure* parent) : | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7789 CMSOopClosure(collector->ref_processor()), |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7790 _collector(collector), |
0 | 7791 _whole_span(collector->_span), |
7792 _span(span), | |
7793 _bit_map(bit_map), | |
7794 _work_queue(work_queue), | |
7795 _overflow_stack(overflow_stack), | |
7796 _finger(finger), | |
7797 _global_finger_addr(global_finger_addr), | |
935 | 7798 _parent(parent) |
0 | 7799 { } |
7800 | |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
7801 // Assumes thread-safe access by callers, who are |
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
7802 // responsible for mutual exclusion. |
0 | 7803 void CMSCollector::lower_restart_addr(HeapWord* low) { |
7804 assert(_span.contains(low), "Out of bounds addr"); | |
7805 if (_restart_addr == NULL) { | |
7806 _restart_addr = low; | |
7807 } else { | |
7808 _restart_addr = MIN2(_restart_addr, low); | |
7809 } | |
7810 } | |
7811 | |
7812 // Upon stack overflow, we discard (part of) the stack, | |
7813 // remembering the least address amongst those discarded | |
7814 // in CMSCollector's _restart_address. | |
7815 void PushOrMarkClosure::handle_stack_overflow(HeapWord* lost) { | |
7816 // Remember the least grey address discarded | |
7817 HeapWord* ra = (HeapWord*)_markStack->least_value(lost); | |
7818 _collector->lower_restart_addr(ra); | |
7819 _markStack->reset(); // discard stack contents | |
7820 _markStack->expand(); // expand the stack if possible | |
7821 } | |
7822 | |
7823 // Upon stack overflow, we discard (part of) the stack, | |
7824 // remembering the least address amongst those discarded | |
7825 // in CMSCollector's _restart_address. | |
7826 void Par_PushOrMarkClosure::handle_stack_overflow(HeapWord* lost) { | |
7827 // We need to do this under a mutex to prevent other | |
340
ebeb6490b814
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
283
diff
changeset
|
7828 // workers from interfering with the work done below. |
0 | 7829 MutexLockerEx ml(_overflow_stack->par_lock(), |
7830 Mutex::_no_safepoint_check_flag); | |
7831 // Remember the least grey address discarded | |
7832 HeapWord* ra = (HeapWord*)_overflow_stack->least_value(lost); | |
7833 _collector->lower_restart_addr(ra); | |
7834 _overflow_stack->reset(); // discard stack contents | |
7835 _overflow_stack->expand(); // expand the stack if possible | |
7836 } | |
7837 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7838 void CMKlassClosure::do_klass(Klass* k) { |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7839 assert(_oop_closure != NULL, "Not initialized?"); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7840 k->oops_do(_oop_closure); |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7841 } |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7842 |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7843 void PushOrMarkClosure::do_oop(oop obj) { |
0 | 7844 // Ignore mark word because we are running concurrent with mutators. |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7845 assert(obj->is_oop_or_null(true), "expected an oop or NULL"); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7846 HeapWord* addr = (HeapWord*)obj; |
0 | 7847 if (_span.contains(addr) && !_bitMap->isMarked(addr)) { |
7848 // Oop lies in _span and isn't yet grey or black | |
7849 _bitMap->mark(addr); // now grey | |
7850 if (addr < _finger) { | |
7851 // the bit map iteration has already either passed, or | |
7852 // sampled, this bit in the bit map; we'll need to | |
7853 // use the marking stack to scan this oop's oops. | |
7854 bool simulate_overflow = false; | |
7855 NOT_PRODUCT( | |
7856 if (CMSMarkStackOverflowALot && | |
7857 _collector->simulate_overflow()) { | |
7858 // simulate a stack overflow | |
7859 simulate_overflow = true; | |
7860 } | |
7861 ) | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7862 if (simulate_overflow || !_markStack->push(obj)) { // stack overflow |
0 | 7863 if (PrintCMSStatistics != 0) { |
7864 gclog_or_tty->print_cr("CMS marking stack overflow (benign) at " | |
7865 SIZE_FORMAT, _markStack->capacity()); | |
7866 } | |
7867 assert(simulate_overflow || _markStack->isFull(), "Else push should have succeeded"); | |
7868 handle_stack_overflow(addr); | |
7869 } | |
7870 } | |
7871 // anything including and to the right of _finger | |
7872 // will be scanned as we iterate over the remainder of the | |
7873 // bit map | |
7874 do_yield_check(); | |
7875 } | |
7876 } | |
7877 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7878 void PushOrMarkClosure::do_oop(oop* p) { PushOrMarkClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7879 void PushOrMarkClosure::do_oop(narrowOop* p) { PushOrMarkClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7880 |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7881 void Par_PushOrMarkClosure::do_oop(oop obj) { |
0 | 7882 // Ignore mark word because we are running concurrent with mutators. |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7883 assert(obj->is_oop_or_null(true), "expected an oop or NULL"); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7884 HeapWord* addr = (HeapWord*)obj; |
0 | 7885 if (_whole_span.contains(addr) && !_bit_map->isMarked(addr)) { |
7886 // Oop lies in _span and isn't yet grey or black | |
7887 // We read the global_finger (volatile read) strictly after marking oop | |
7888 bool res = _bit_map->par_mark(addr); // now grey | |
7889 volatile HeapWord** gfa = (volatile HeapWord**)_global_finger_addr; | |
7890 // Should we push this marked oop on our stack? | |
7891 // -- if someone else marked it, nothing to do | |
7892 // -- if target oop is above global finger nothing to do | |
7893 // -- if target oop is in chunk and above local finger | |
7894 // then nothing to do | |
7895 // -- else push on work queue | |
7896 if ( !res // someone else marked it, they will deal with it | |
7897 || (addr >= *gfa) // will be scanned in a later task | |
7898 || (_span.contains(addr) && addr >= _finger)) { // later in this chunk | |
7899 return; | |
7900 } | |
7901 // the bit map iteration has already either passed, or | |
7902 // sampled, this bit in the bit map; we'll need to | |
7903 // use the marking stack to scan this oop's oops. | |
7904 bool simulate_overflow = false; | |
7905 NOT_PRODUCT( | |
7906 if (CMSMarkStackOverflowALot && | |
7907 _collector->simulate_overflow()) { | |
7908 // simulate a stack overflow | |
7909 simulate_overflow = true; | |
7910 } | |
7911 ) | |
7912 if (simulate_overflow || | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7913 !(_work_queue->push(obj) || _overflow_stack->par_push(obj))) { |
0 | 7914 // stack overflow |
7915 if (PrintCMSStatistics != 0) { | |
7916 gclog_or_tty->print_cr("CMS marking stack overflow (benign) at " | |
7917 SIZE_FORMAT, _overflow_stack->capacity()); | |
7918 } | |
7919 // We cannot assert that the overflow stack is full because | |
7920 // it may have been emptied since. | |
7921 assert(simulate_overflow || | |
7922 _work_queue->size() == _work_queue->max_elems(), | |
7923 "Else push should have succeeded"); | |
7924 handle_stack_overflow(addr); | |
7925 } | |
7926 do_yield_check(); | |
7927 } | |
7928 } | |
7929 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7930 void Par_PushOrMarkClosure::do_oop(oop* p) { Par_PushOrMarkClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7931 void Par_PushOrMarkClosure::do_oop(narrowOop* p) { Par_PushOrMarkClosure::do_oop_work(p); } |
0 | 7932 |
7933 PushAndMarkClosure::PushAndMarkClosure(CMSCollector* collector, | |
7934 MemRegion span, | |
7935 ReferenceProcessor* rp, | |
7936 CMSBitMap* bit_map, | |
7937 CMSBitMap* mod_union_table, | |
7938 CMSMarkStack* mark_stack, | |
7939 bool concurrent_precleaning): | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7940 CMSOopClosure(rp), |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
7941 _collector(collector), |
0 | 7942 _span(span), |
7943 _bit_map(bit_map), | |
7944 _mod_union_table(mod_union_table), | |
7945 _mark_stack(mark_stack), | |
935 | 7946 _concurrent_precleaning(concurrent_precleaning) |
0 | 7947 { |
7948 assert(_ref_processor != NULL, "_ref_processor shouldn't be NULL"); | |
7949 } | |
7950 | |
7951 // Grey object rescan during pre-cleaning and second checkpoint phases -- | |
7952 // the non-parallel version (the parallel version appears further below.) | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7953 void PushAndMarkClosure::do_oop(oop obj) { |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7954 // Ignore mark word verification. If during concurrent precleaning, |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7955 // the object monitor may be locked. If during the checkpoint |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7956 // phases, the object may already have been reached by a different |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7957 // path and may be at the end of the global overflow list (so |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7958 // the mark word may be NULL). |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
143
diff
changeset
|
7959 assert(obj->is_oop_or_null(true /* ignore mark word */), |
0 | 7960 "expected an oop or NULL"); |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7961 HeapWord* addr = (HeapWord*)obj; |
0 | 7962 // Check if oop points into the CMS generation |
7963 // and is not marked | |
7964 if (_span.contains(addr) && !_bit_map->isMarked(addr)) { | |
7965 // a white object ... | |
7966 _bit_map->mark(addr); // ... now grey | |
7967 // push on the marking stack (grey set) | |
7968 bool simulate_overflow = false; | |
7969 NOT_PRODUCT( | |
7970 if (CMSMarkStackOverflowALot && | |
7971 _collector->simulate_overflow()) { | |
7972 // simulate a stack overflow | |
7973 simulate_overflow = true; | |
7974 } | |
7975 ) | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
7976 if (simulate_overflow || !_mark_stack->push(obj)) { |
0 | 7977 if (_concurrent_precleaning) { |
283
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7978 // During precleaning we can just dirty the appropriate card(s) |
0 | 7979 // in the mod union table, thus ensuring that the object remains |
283
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7980 // in the grey set and continue. In the case of object arrays |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7981 // we need to dirty all of the cards that the object spans, |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7982 // since the rescan of object arrays will be limited to the |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7983 // dirty cards. |
14309 | 7984 // Note that no one can be interfering with us in this action |
283
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7985 // of dirtying the mod union table, so no locking or atomics |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7986 // are required. |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7987 if (obj->is_objArray()) { |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7988 size_t sz = obj->size(); |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7989 HeapWord* end_card_addr = (HeapWord*)round_to( |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7990 (intptr_t)(addr+sz), CardTableModRefBS::card_size); |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7991 MemRegion redirty_range = MemRegion(addr, end_card_addr); |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7992 assert(!redirty_range.is_empty(), "Arithmetical tautology"); |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7993 _mod_union_table->mark_range(redirty_range); |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7994 } else { |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7995 _mod_union_table->mark(addr); |
9199f248b0ee
6722112: CMS: Incorrect encoding of overflown object arrays during concurrent precleaning
ysr
parents:
271
diff
changeset
|
7996 } |
0 | 7997 _collector->_ser_pmc_preclean_ovflw++; |
7998 } else { | |
7999 // During the remark phase, we need to remember this oop | |
8000 // in the overflow list. | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8001 _collector->push_on_overflow_list(obj); |
0 | 8002 _collector->_ser_pmc_remark_ovflw++; |
8003 } | |
8004 } | |
8005 } | |
8006 } | |
8007 | |
8008 Par_PushAndMarkClosure::Par_PushAndMarkClosure(CMSCollector* collector, | |
8009 MemRegion span, | |
8010 ReferenceProcessor* rp, | |
8011 CMSBitMap* bit_map, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
8012 OopTaskQueue* work_queue): |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
8013 CMSOopClosure(rp), |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
8014 _collector(collector), |
0 | 8015 _span(span), |
8016 _bit_map(bit_map), | |
935 | 8017 _work_queue(work_queue) |
0 | 8018 { |
8019 assert(_ref_processor != NULL, "_ref_processor shouldn't be NULL"); | |
8020 } | |
8021 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8022 void PushAndMarkClosure::do_oop(oop* p) { PushAndMarkClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8023 void PushAndMarkClosure::do_oop(narrowOop* p) { PushAndMarkClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8024 |
0 | 8025 // Grey object rescan during second checkpoint phase -- |
8026 // the parallel version. | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8027 void Par_PushAndMarkClosure::do_oop(oop obj) { |
0 | 8028 // In the assert below, we ignore the mark word because |
8029 // this oop may point to an already visited object that is | |
8030 // on the overflow stack (in which case the mark word has | |
8031 // been hijacked for chaining into the overflow stack -- | |
8032 // if this is the last object in the overflow stack then | |
8033 // its mark word will be NULL). Because this object may | |
8034 // have been subsequently popped off the global overflow | |
8035 // stack, and the mark word possibly restored to the prototypical | |
8036 // value, by the time we get to examined this failing assert in | |
8037 // the debugger, is_oop_or_null(false) may subsequently start | |
8038 // to hold. | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8039 assert(obj->is_oop_or_null(true), |
0 | 8040 "expected an oop or NULL"); |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8041 HeapWord* addr = (HeapWord*)obj; |
0 | 8042 // Check if oop points into the CMS generation |
8043 // and is not marked | |
8044 if (_span.contains(addr) && !_bit_map->isMarked(addr)) { | |
8045 // a white object ... | |
8046 // If we manage to "claim" the object, by being the | |
8047 // first thread to mark it, then we push it on our | |
8048 // marking stack | |
8049 if (_bit_map->par_mark(addr)) { // ... now grey | |
8050 // push on work queue (grey set) | |
8051 bool simulate_overflow = false; | |
8052 NOT_PRODUCT( | |
8053 if (CMSMarkStackOverflowALot && | |
8054 _collector->par_simulate_overflow()) { | |
8055 // simulate a stack overflow | |
8056 simulate_overflow = true; | |
8057 } | |
8058 ) | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8059 if (simulate_overflow || !_work_queue->push(obj)) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8060 _collector->par_push_on_overflow_list(obj); |
0 | 8061 _collector->_par_pmc_remark_ovflw++; // imprecise OK: no need to CAS |
8062 } | |
8063 } // Else, some other thread got there first | |
8064 } | |
8065 } | |
8066 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8067 void Par_PushAndMarkClosure::do_oop(oop* p) { Par_PushAndMarkClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8068 void Par_PushAndMarkClosure::do_oop(narrowOop* p) { Par_PushAndMarkClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8069 |
0 | 8070 void CMSPrecleanRefsYieldClosure::do_yield_work() { |
8071 Mutex* bml = _collector->bitMapLock(); | |
8072 assert_lock_strong(bml); | |
8073 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
8074 "CMS thread should hold CMS token"); | |
8075 | |
8076 bml->unlock(); | |
8077 ConcurrentMarkSweepThread::desynchronize(true); | |
8078 | |
8079 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
8080 | |
8081 _collector->stopTimer(); | |
8082 GCPauseTimer p(_collector->size_policy()->concurrent_timer_ptr()); | |
8083 if (PrintCMSStatistics != 0) { | |
8084 _collector->incrementYields(); | |
8085 } | |
8086 _collector->icms_wait(); | |
8087 | |
8088 // See the comment in coordinator_yield() | |
8089 for (unsigned i = 0; i < CMSYieldSleepCount && | |
8090 ConcurrentMarkSweepThread::should_yield() && | |
8091 !CMSCollector::foregroundGCIsActive(); ++i) { | |
8092 os::sleep(Thread::current(), 1, false); | |
8093 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
8094 } | |
8095 | |
8096 ConcurrentMarkSweepThread::synchronize(true); | |
8097 bml->lock(); | |
8098 | |
8099 _collector->startTimer(); | |
8100 } | |
8101 | |
8102 bool CMSPrecleanRefsYieldClosure::should_return() { | |
8103 if (ConcurrentMarkSweepThread::should_yield()) { | |
8104 do_yield_work(); | |
8105 } | |
8106 return _collector->foregroundGCIsActive(); | |
8107 } | |
8108 | |
8109 void MarkFromDirtyCardsClosure::do_MemRegion(MemRegion mr) { | |
8110 assert(((size_t)mr.start())%CardTableModRefBS::card_size_in_words == 0, | |
8111 "mr should be aligned to start at a card boundary"); | |
8112 // We'd like to assert: | |
8113 // assert(mr.word_size()%CardTableModRefBS::card_size_in_words == 0, | |
8114 // "mr should be a range of cards"); | |
8115 // However, that would be too strong in one case -- the last | |
8116 // partition ends at _unallocated_block which, in general, can be | |
8117 // an arbitrary boundary, not necessarily card aligned. | |
8118 if (PrintCMSStatistics != 0) { | |
8119 _num_dirty_cards += | |
8120 mr.word_size()/CardTableModRefBS::card_size_in_words; | |
8121 } | |
8122 _space->object_iterate_mem(mr, &_scan_cl); | |
8123 } | |
8124 | |
8125 SweepClosure::SweepClosure(CMSCollector* collector, | |
8126 ConcurrentMarkSweepGeneration* g, | |
8127 CMSBitMap* bitMap, bool should_yield) : | |
8128 _collector(collector), | |
8129 _g(g), | |
8130 _sp(g->cmsSpace()), | |
8131 _limit(_sp->sweep_limit()), | |
8132 _freelistLock(_sp->freelistLock()), | |
8133 _bitMap(bitMap), | |
8134 _yield(should_yield), | |
8135 _inFreeRange(false), // No free range at beginning of sweep | |
8136 _freeRangeInFreeLists(false), // No free range at beginning of sweep | |
8137 _lastFreeRangeCoalesced(false), | |
8138 _freeFinger(g->used_region().start()) | |
8139 { | |
8140 NOT_PRODUCT( | |
8141 _numObjectsFreed = 0; | |
8142 _numWordsFreed = 0; | |
8143 _numObjectsLive = 0; | |
8144 _numWordsLive = 0; | |
8145 _numObjectsAlreadyFree = 0; | |
8146 _numWordsAlreadyFree = 0; | |
8147 _last_fc = NULL; | |
8148 | |
8149 _sp->initializeIndexedFreeListArrayReturnedBytes(); | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8150 _sp->dictionary()->initialize_dict_returned_bytes(); |
0 | 8151 ) |
8152 assert(_limit >= _sp->bottom() && _limit <= _sp->end(), | |
8153 "sweep _limit out of bounds"); | |
8154 if (CMSTraceSweeper) { | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8155 gclog_or_tty->print_cr("\n====================\nStarting new sweep with limit " PTR_FORMAT, |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8156 _limit); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8157 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8158 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8159 |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8160 void SweepClosure::print_on(outputStream* st) const { |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8161 tty->print_cr("_sp = [" PTR_FORMAT "," PTR_FORMAT ")", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8162 _sp->bottom(), _sp->end()); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8163 tty->print_cr("_limit = " PTR_FORMAT, _limit); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8164 tty->print_cr("_freeFinger = " PTR_FORMAT, _freeFinger); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8165 NOT_PRODUCT(tty->print_cr("_last_fc = " PTR_FORMAT, _last_fc);) |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8166 tty->print_cr("_inFreeRange = %d, _freeRangeInFreeLists = %d, _lastFreeRangeCoalesced = %d", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8167 _inFreeRange, _freeRangeInFreeLists, _lastFreeRangeCoalesced); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8168 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8169 |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8170 #ifndef PRODUCT |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8171 // Assertion checking only: no useful work in product mode -- |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8172 // however, if any of the flags below become product flags, |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8173 // you may need to review this code to see if it needs to be |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8174 // enabled in product mode. |
0 | 8175 SweepClosure::~SweepClosure() { |
8176 assert_lock_strong(_freelistLock); | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8177 assert(_limit >= _sp->bottom() && _limit <= _sp->end(), |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8178 "sweep _limit out of bounds"); |
0 | 8179 if (inFreeRange()) { |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8180 warning("inFreeRange() should have been reset; dumping state of SweepClosure"); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8181 print(); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8182 ShouldNotReachHere(); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8183 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8184 if (Verbose && PrintGC) { |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8185 gclog_or_tty->print("Collected "SIZE_FORMAT" objects, " SIZE_FORMAT " bytes", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8186 _numObjectsFreed, _numWordsFreed*sizeof(HeapWord)); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8187 gclog_or_tty->print_cr("\nLive "SIZE_FORMAT" objects, " |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8188 SIZE_FORMAT" bytes " |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8189 "Already free "SIZE_FORMAT" objects, "SIZE_FORMAT" bytes", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8190 _numObjectsLive, _numWordsLive*sizeof(HeapWord), |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8191 _numObjectsAlreadyFree, _numWordsAlreadyFree*sizeof(HeapWord)); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8192 size_t totalBytes = (_numWordsFreed + _numWordsLive + _numWordsAlreadyFree) |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8193 * sizeof(HeapWord); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8194 gclog_or_tty->print_cr("Total sweep: "SIZE_FORMAT" bytes", totalBytes); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8195 |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8196 if (PrintCMSStatistics && CMSVerifyReturnedBytes) { |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8197 size_t indexListReturnedBytes = _sp->sumIndexedFreeListArrayReturnedBytes(); |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8198 size_t dict_returned_bytes = _sp->dictionary()->sum_dict_returned_bytes(); |
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8199 size_t returned_bytes = indexListReturnedBytes + dict_returned_bytes; |
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8200 gclog_or_tty->print("Returned "SIZE_FORMAT" bytes", returned_bytes); |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8201 gclog_or_tty->print(" Indexed List Returned "SIZE_FORMAT" bytes", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8202 indexListReturnedBytes); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8203 gclog_or_tty->print_cr(" Dictionary Returned "SIZE_FORMAT" bytes", |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8204 dict_returned_bytes); |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8205 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8206 } |
0 | 8207 if (CMSTraceSweeper) { |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8208 gclog_or_tty->print_cr("end of sweep with _limit = " PTR_FORMAT "\n================", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8209 _limit); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8210 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8211 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8212 #endif // PRODUCT |
0 | 8213 |
8214 void SweepClosure::initialize_free_range(HeapWord* freeFinger, | |
8215 bool freeRangeInFreeLists) { | |
8216 if (CMSTraceSweeper) { | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8217 gclog_or_tty->print("---- Start free range at 0x%x with free block (%d)\n", |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8218 freeFinger, freeRangeInFreeLists); |
0 | 8219 } |
8220 assert(!inFreeRange(), "Trampling existing free range"); | |
8221 set_inFreeRange(true); | |
8222 set_lastFreeRangeCoalesced(false); | |
8223 | |
8224 set_freeFinger(freeFinger); | |
8225 set_freeRangeInFreeLists(freeRangeInFreeLists); | |
8226 if (CMSTestInFreeList) { | |
8227 if (freeRangeInFreeLists) { | |
8228 FreeChunk* fc = (FreeChunk*) freeFinger; | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8229 assert(fc->is_free(), "A chunk on the free list should be free."); |
0 | 8230 assert(fc->size() > 0, "Free range should have a size"); |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8231 assert(_sp->verify_chunk_in_free_list(fc), "Chunk is not in free lists"); |
0 | 8232 } |
8233 } | |
8234 } | |
8235 | |
8236 // Note that the sweeper runs concurrently with mutators. Thus, | |
8237 // it is possible for direct allocation in this generation to happen | |
8238 // in the middle of the sweep. Note that the sweeper also coalesces | |
8239 // contiguous free blocks. Thus, unless the sweeper and the allocator | |
8240 // synchronize appropriately freshly allocated blocks may get swept up. | |
8241 // This is accomplished by the sweeper locking the free lists while | |
8242 // it is sweeping. Thus blocks that are determined to be free are | |
8243 // indeed free. There is however one additional complication: | |
8244 // blocks that have been allocated since the final checkpoint and | |
8245 // mark, will not have been marked and so would be treated as | |
8246 // unreachable and swept up. To prevent this, the allocator marks | |
8247 // the bit map when allocating during the sweep phase. This leads, | |
8248 // however, to a further complication -- objects may have been allocated | |
8249 // but not yet initialized -- in the sense that the header isn't yet | |
8250 // installed. The sweeper can not then determine the size of the block | |
8251 // in order to skip over it. To deal with this case, we use a technique | |
8252 // (due to Printezis) to encode such uninitialized block sizes in the | |
8253 // bit map. Since the bit map uses a bit per every HeapWord, but the | |
8254 // CMS generation has a minimum object size of 3 HeapWords, it follows | |
8255 // that "normal marks" won't be adjacent in the bit map (there will | |
8256 // always be at least two 0 bits between successive 1 bits). We make use | |
8257 // of these "unused" bits to represent uninitialized blocks -- the bit | |
8258 // corresponding to the start of the uninitialized object and the next | |
8259 // bit are both set. Finally, a 1 bit marks the end of the object that | |
8260 // started with the two consecutive 1 bits to indicate its potentially | |
8261 // uninitialized state. | |
8262 | |
8263 size_t SweepClosure::do_blk_careful(HeapWord* addr) { | |
8264 FreeChunk* fc = (FreeChunk*)addr; | |
8265 size_t res; | |
8266 | |
1720
5ed703250bff
6977970: CMS: concurrentMarkSweepGeneration.cpp:7947 assert(addr <= _limit) failed: sweep invariant
ysr
parents:
1716
diff
changeset
|
8267 // Check if we are done sweeping. Below we check "addr >= _limit" rather |
5ed703250bff
6977970: CMS: concurrentMarkSweepGeneration.cpp:7947 assert(addr <= _limit) failed: sweep invariant
ysr
parents:
1716
diff
changeset
|
8268 // than "addr == _limit" because although _limit was a block boundary when |
5ed703250bff
6977970: CMS: concurrentMarkSweepGeneration.cpp:7947 assert(addr <= _limit) failed: sweep invariant
ysr
parents:
1716
diff
changeset
|
8269 // we started the sweep, it may no longer be one because heap expansion |
5ed703250bff
6977970: CMS: concurrentMarkSweepGeneration.cpp:7947 assert(addr <= _limit) failed: sweep invariant
ysr
parents:
1716
diff
changeset
|
8270 // may have caused us to coalesce the block ending at the address _limit |
5ed703250bff
6977970: CMS: concurrentMarkSweepGeneration.cpp:7947 assert(addr <= _limit) failed: sweep invariant
ysr
parents:
1716
diff
changeset
|
8271 // with a newly expanded chunk (this happens when _limit was set to the |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8272 // previous _end of the space), so we may have stepped past _limit: |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8273 // see the following Zeno-like trail of CRs 6977970, 7008136, 7042740. |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8274 if (addr >= _limit) { // we have swept up to or past the limit: finish up |
0 | 8275 assert(_limit >= _sp->bottom() && _limit <= _sp->end(), |
8276 "sweep _limit out of bounds"); | |
1720
5ed703250bff
6977970: CMS: concurrentMarkSweepGeneration.cpp:7947 assert(addr <= _limit) failed: sweep invariant
ysr
parents:
1716
diff
changeset
|
8277 assert(addr < _sp->end(), "addr out of bounds"); |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8278 // Flush any free range we might be holding as a single |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8279 // coalesced chunk to the appropriate free list. |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8280 if (inFreeRange()) { |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8281 assert(freeFinger() >= _sp->bottom() && freeFinger() < _limit, |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8282 err_msg("freeFinger() " PTR_FORMAT" is out-of-bounds", freeFinger())); |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8283 flush_cur_free_chunk(freeFinger(), |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8284 pointer_delta(addr, freeFinger())); |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8285 if (CMSTraceSweeper) { |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8286 gclog_or_tty->print("Sweep: last chunk: "); |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8287 gclog_or_tty->print("put_free_blk 0x%x ("SIZE_FORMAT") " |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8288 "[coalesced:"SIZE_FORMAT"]\n", |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8289 freeFinger(), pointer_delta(addr, freeFinger()), |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8290 lastFreeRangeCoalesced()); |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8291 } |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8292 } |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8293 |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8294 // help the iterator loop finish |
1720
5ed703250bff
6977970: CMS: concurrentMarkSweepGeneration.cpp:7947 assert(addr <= _limit) failed: sweep invariant
ysr
parents:
1716
diff
changeset
|
8295 return pointer_delta(_sp->end(), addr); |
5ed703250bff
6977970: CMS: concurrentMarkSweepGeneration.cpp:7947 assert(addr <= _limit) failed: sweep invariant
ysr
parents:
1716
diff
changeset
|
8296 } |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8297 |
1720
5ed703250bff
6977970: CMS: concurrentMarkSweepGeneration.cpp:7947 assert(addr <= _limit) failed: sweep invariant
ysr
parents:
1716
diff
changeset
|
8298 assert(addr < _limit, "sweep invariant"); |
0 | 8299 // check if we should yield |
8300 do_yield_check(addr); | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8301 if (fc->is_free()) { |
0 | 8302 // Chunk that is already free |
8303 res = fc->size(); | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8304 do_already_free_chunk(fc); |
0 | 8305 debug_only(_sp->verifyFreeLists()); |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8306 // If we flush the chunk at hand in lookahead_and_flush() |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8307 // and it's coalesced with a preceding chunk, then the |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8308 // process of "mangling" the payload of the coalesced block |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8309 // will cause erasure of the size information from the |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8310 // (erstwhile) header of all the coalesced blocks but the |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8311 // first, so the first disjunct in the assert will not hold |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8312 // in that specific case (in which case the second disjunct |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8313 // will hold). |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8314 assert(res == fc->size() || ((HeapWord*)fc) + res >= _limit, |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8315 "Otherwise the size info doesn't change at this step"); |
0 | 8316 NOT_PRODUCT( |
8317 _numObjectsAlreadyFree++; | |
8318 _numWordsAlreadyFree += res; | |
8319 ) | |
8320 NOT_PRODUCT(_last_fc = fc;) | |
8321 } else if (!_bitMap->isMarked(addr)) { | |
8322 // Chunk is fresh garbage | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8323 res = do_garbage_chunk(fc); |
0 | 8324 debug_only(_sp->verifyFreeLists()); |
8325 NOT_PRODUCT( | |
8326 _numObjectsFreed++; | |
8327 _numWordsFreed += res; | |
8328 ) | |
8329 } else { | |
8330 // Chunk that is alive. | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8331 res = do_live_chunk(fc); |
0 | 8332 debug_only(_sp->verifyFreeLists()); |
8333 NOT_PRODUCT( | |
8334 _numObjectsLive++; | |
8335 _numWordsLive += res; | |
8336 ) | |
8337 } | |
8338 return res; | |
8339 } | |
8340 | |
8341 // For the smart allocation, record following | |
8342 // split deaths - a free chunk is removed from its free list because | |
8343 // it is being split into two or more chunks. | |
8344 // split birth - a free chunk is being added to its free list because | |
8345 // a larger free chunk has been split and resulted in this free chunk. | |
8346 // coal death - a free chunk is being removed from its free list because | |
8347 // it is being coalesced into a large free chunk. | |
8348 // coal birth - a free chunk is being added to its free list because | |
8349 // it was created when two or more free chunks where coalesced into | |
8350 // this free chunk. | |
8351 // | |
8352 // These statistics are used to determine the desired number of free | |
8353 // chunks of a given size. The desired number is chosen to be relative | |
8354 // to the end of a CMS sweep. The desired number at the end of a sweep | |
8355 // is the | |
8356 // count-at-end-of-previous-sweep (an amount that was enough) | |
8357 // - count-at-beginning-of-current-sweep (the excess) | |
8358 // + split-births (gains in this size during interval) | |
8359 // - split-deaths (demands on this size during interval) | |
8360 // where the interval is from the end of one sweep to the end of the | |
8361 // next. | |
8362 // | |
8363 // When sweeping the sweeper maintains an accumulated chunk which is | |
8364 // the chunk that is made up of chunks that have been coalesced. That | |
8365 // will be termed the left-hand chunk. A new chunk of garbage that | |
8366 // is being considered for coalescing will be referred to as the | |
8367 // right-hand chunk. | |
8368 // | |
8369 // When making a decision on whether to coalesce a right-hand chunk with | |
8370 // the current left-hand chunk, the current count vs. the desired count | |
8371 // of the left-hand chunk is considered. Also if the right-hand chunk | |
8372 // is near the large chunk at the end of the heap (see | |
8373 // ConcurrentMarkSweepGeneration::isNearLargestChunk()), then the | |
8374 // left-hand chunk is coalesced. | |
8375 // | |
8376 // When making a decision about whether to split a chunk, the desired count | |
8377 // vs. the current count of the candidate to be split is also considered. | |
8378 // If the candidate is underpopulated (currently fewer chunks than desired) | |
8379 // a chunk of an overpopulated (currently more chunks than desired) size may | |
8380 // be chosen. The "hint" associated with a free list, if non-null, points | |
8381 // to a free list which may be overpopulated. | |
8382 // | |
8383 | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8384 void SweepClosure::do_already_free_chunk(FreeChunk* fc) { |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8385 const size_t size = fc->size(); |
0 | 8386 // Chunks that cannot be coalesced are not in the |
8387 // free lists. | |
8388 if (CMSTestInFreeList && !fc->cantCoalesce()) { | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8389 assert(_sp->verify_chunk_in_free_list(fc), |
0 | 8390 "free chunk should be in free lists"); |
8391 } | |
8392 // a chunk that is already free, should not have been | |
8393 // marked in the bit map | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8394 HeapWord* const addr = (HeapWord*) fc; |
0 | 8395 assert(!_bitMap->isMarked(addr), "free chunk should be unmarked"); |
8396 // Verify that the bit map has no bits marked between | |
8397 // addr and purported end of this block. | |
8398 _bitMap->verifyNoOneBitsInRange(addr + 1, addr + size); | |
8399 | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8400 // Some chunks cannot be coalesced under any circumstances. |
0 | 8401 // See the definition of cantCoalesce(). |
8402 if (!fc->cantCoalesce()) { | |
8403 // This chunk can potentially be coalesced. | |
8404 if (_sp->adaptive_freelists()) { | |
8405 // All the work is done in | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8406 do_post_free_or_garbage_chunk(fc, size); |
0 | 8407 } else { // Not adaptive free lists |
8408 // this is a free chunk that can potentially be coalesced by the sweeper; | |
8409 if (!inFreeRange()) { | |
8410 // if the next chunk is a free block that can't be coalesced | |
8411 // it doesn't make sense to remove this chunk from the free lists | |
8412 FreeChunk* nextChunk = (FreeChunk*)(addr + size); | |
2136
c91cc404ca46
7011940: iCMS: SIGSEGV in SweepClosure::do_already_free_chunk(FreeChunk*)+0x360
ysr
parents:
2132
diff
changeset
|
8413 assert((HeapWord*)nextChunk <= _sp->end(), "Chunk size out of bounds?"); |
c91cc404ca46
7011940: iCMS: SIGSEGV in SweepClosure::do_already_free_chunk(FreeChunk*)+0x360
ysr
parents:
2132
diff
changeset
|
8414 if ((HeapWord*)nextChunk < _sp->end() && // There is another free chunk to the right ... |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8415 nextChunk->is_free() && // ... which is free... |
2136
c91cc404ca46
7011940: iCMS: SIGSEGV in SweepClosure::do_already_free_chunk(FreeChunk*)+0x360
ysr
parents:
2132
diff
changeset
|
8416 nextChunk->cantCoalesce()) { // ... but can't be coalesced |
0 | 8417 // nothing to do |
8418 } else { | |
8419 // Potentially the start of a new free range: | |
8420 // Don't eagerly remove it from the free lists. | |
8421 // No need to remove it if it will just be put | |
8422 // back again. (Also from a pragmatic point of view | |
8423 // if it is a free block in a region that is beyond | |
8424 // any allocated blocks, an assertion will fail) | |
8425 // Remember the start of a free run. | |
8426 initialize_free_range(addr, true); | |
8427 // end - can coalesce with next chunk | |
8428 } | |
8429 } else { | |
8430 // the midst of a free range, we are coalescing | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8431 print_free_block_coalesced(fc); |
0 | 8432 if (CMSTraceSweeper) { |
8433 gclog_or_tty->print(" -- pick up free block 0x%x (%d)\n", fc, size); | |
8434 } | |
8435 // remove it from the free lists | |
8436 _sp->removeFreeChunkFromFreeLists(fc); | |
8437 set_lastFreeRangeCoalesced(true); | |
8438 // If the chunk is being coalesced and the current free range is | |
8439 // in the free lists, remove the current free range so that it | |
8440 // will be returned to the free lists in its entirety - all | |
8441 // the coalesced pieces included. | |
8442 if (freeRangeInFreeLists()) { | |
8443 FreeChunk* ffc = (FreeChunk*) freeFinger(); | |
8444 assert(ffc->size() == pointer_delta(addr, freeFinger()), | |
8445 "Size of free range is inconsistent with chunk size."); | |
8446 if (CMSTestInFreeList) { | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8447 assert(_sp->verify_chunk_in_free_list(ffc), |
0 | 8448 "free range is not in free lists"); |
8449 } | |
8450 _sp->removeFreeChunkFromFreeLists(ffc); | |
8451 set_freeRangeInFreeLists(false); | |
8452 } | |
8453 } | |
8454 } | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8455 // Note that if the chunk is not coalescable (the else arm |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8456 // below), we unconditionally flush, without needing to do |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8457 // a "lookahead," as we do below. |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8458 if (inFreeRange()) lookahead_and_flush(fc, size); |
0 | 8459 } else { |
8460 // Code path common to both original and adaptive free lists. | |
8461 | |
8462 // cant coalesce with previous block; this should be treated | |
8463 // as the end of a free run if any | |
8464 if (inFreeRange()) { | |
8465 // we kicked some butt; time to pick up the garbage | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8466 assert(freeFinger() < addr, "freeFinger points too high"); |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8467 flush_cur_free_chunk(freeFinger(), pointer_delta(addr, freeFinger())); |
0 | 8468 } |
8469 // else, nothing to do, just continue | |
8470 } | |
8471 } | |
8472 | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8473 size_t SweepClosure::do_garbage_chunk(FreeChunk* fc) { |
0 | 8474 // This is a chunk of garbage. It is not in any free list. |
8475 // Add it to a free list or let it possibly be coalesced into | |
8476 // a larger chunk. | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8477 HeapWord* const addr = (HeapWord*) fc; |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8478 const size_t size = CompactibleFreeListSpace::adjustObjectSize(oop(addr)->size()); |
0 | 8479 |
8480 if (_sp->adaptive_freelists()) { | |
8481 // Verify that the bit map has no bits marked between | |
8482 // addr and purported end of just dead object. | |
8483 _bitMap->verifyNoOneBitsInRange(addr + 1, addr + size); | |
8484 | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8485 do_post_free_or_garbage_chunk(fc, size); |
0 | 8486 } else { |
8487 if (!inFreeRange()) { | |
8488 // start of a new free range | |
8489 assert(size > 0, "A free range should have a size"); | |
8490 initialize_free_range(addr, false); | |
8491 } else { | |
8492 // this will be swept up when we hit the end of the | |
8493 // free range | |
8494 if (CMSTraceSweeper) { | |
8495 gclog_or_tty->print(" -- pick up garbage 0x%x (%d) \n", fc, size); | |
8496 } | |
8497 // If the chunk is being coalesced and the current free range is | |
8498 // in the free lists, remove the current free range so that it | |
8499 // will be returned to the free lists in its entirety - all | |
8500 // the coalesced pieces included. | |
8501 if (freeRangeInFreeLists()) { | |
8502 FreeChunk* ffc = (FreeChunk*)freeFinger(); | |
8503 assert(ffc->size() == pointer_delta(addr, freeFinger()), | |
8504 "Size of free range is inconsistent with chunk size."); | |
8505 if (CMSTestInFreeList) { | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8506 assert(_sp->verify_chunk_in_free_list(ffc), |
0 | 8507 "free range is not in free lists"); |
8508 } | |
8509 _sp->removeFreeChunkFromFreeLists(ffc); | |
8510 set_freeRangeInFreeLists(false); | |
8511 } | |
8512 set_lastFreeRangeCoalesced(true); | |
8513 } | |
8514 // this will be swept up when we hit the end of the free range | |
8515 | |
8516 // Verify that the bit map has no bits marked between | |
8517 // addr and purported end of just dead object. | |
8518 _bitMap->verifyNoOneBitsInRange(addr + 1, addr + size); | |
8519 } | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8520 assert(_limit >= addr + size, |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8521 "A freshly garbage chunk can't possibly straddle over _limit"); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8522 if (inFreeRange()) lookahead_and_flush(fc, size); |
0 | 8523 return size; |
8524 } | |
8525 | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8526 size_t SweepClosure::do_live_chunk(FreeChunk* fc) { |
0 | 8527 HeapWord* addr = (HeapWord*) fc; |
8528 // The sweeper has just found a live object. Return any accumulated | |
8529 // left hand chunk to the free lists. | |
8530 if (inFreeRange()) { | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8531 assert(freeFinger() < addr, "freeFinger points too high"); |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8532 flush_cur_free_chunk(freeFinger(), pointer_delta(addr, freeFinger())); |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8533 } |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8534 |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8535 // This object is live: we'd normally expect this to be |
0 | 8536 // an oop, and like to assert the following: |
8537 // assert(oop(addr)->is_oop(), "live block should be an oop"); | |
8538 // However, as we commented above, this may be an object whose | |
8539 // header hasn't yet been initialized. | |
8540 size_t size; | |
8541 assert(_bitMap->isMarked(addr), "Tautology for this control point"); | |
8542 if (_bitMap->isMarked(addr + 1)) { | |
8543 // Determine the size from the bit map, rather than trying to | |
8544 // compute it from the object header. | |
8545 HeapWord* nextOneAddr = _bitMap->getNextMarkedWordAddress(addr + 2); | |
8546 size = pointer_delta(nextOneAddr + 1, addr); | |
8547 assert(size == CompactibleFreeListSpace::adjustObjectSize(size), | |
8548 "alignment problem"); | |
8549 | |
9152 | 8550 #ifdef ASSERT |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
8551 if (oop(addr)->klass_or_null() != NULL) { |
0 | 8552 // Ignore mark word because we are running concurrent with mutators |
8553 assert(oop(addr)->is_oop(true), "live block should be an oop"); | |
8554 assert(size == | |
8555 CompactibleFreeListSpace::adjustObjectSize(oop(addr)->size()), | |
8556 "P-mark and computed size do not agree"); | |
8557 } | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8558 #endif |
0 | 8559 |
8560 } else { | |
8561 // This should be an initialized object that's alive. | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
8562 assert(oop(addr)->klass_or_null() != NULL, |
0 | 8563 "Should be an initialized object"); |
8564 // Ignore mark word because we are running concurrent with mutators | |
8565 assert(oop(addr)->is_oop(true), "live block should be an oop"); | |
8566 // Verify that the bit map has no bits marked between | |
8567 // addr and purported end of this block. | |
8568 size = CompactibleFreeListSpace::adjustObjectSize(oop(addr)->size()); | |
8569 assert(size >= 3, "Necessary for Printezis marks to work"); | |
8570 assert(!_bitMap->isMarked(addr+1), "Tautology for this control point"); | |
8571 DEBUG_ONLY(_bitMap->verifyNoOneBitsInRange(addr+2, addr+size);) | |
8572 } | |
8573 return size; | |
8574 } | |
8575 | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8576 void SweepClosure::do_post_free_or_garbage_chunk(FreeChunk* fc, |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8577 size_t chunkSize) { |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8578 // do_post_free_or_garbage_chunk() should only be called in the case |
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8579 // of the adaptive free list allocator. |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8580 const bool fcInFreeLists = fc->is_free(); |
0 | 8581 assert(_sp->adaptive_freelists(), "Should only be used in this case."); |
8582 assert((HeapWord*)fc <= _limit, "sweep invariant"); | |
8583 if (CMSTestInFreeList && fcInFreeLists) { | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8584 assert(_sp->verify_chunk_in_free_list(fc), "free chunk is not in free lists"); |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8585 } |
0 | 8586 |
8587 if (CMSTraceSweeper) { | |
8588 gclog_or_tty->print_cr(" -- pick up another chunk at 0x%x (%d)", fc, chunkSize); | |
8589 } | |
8590 | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8591 HeapWord* const fc_addr = (HeapWord*) fc; |
0 | 8592 |
8593 bool coalesce; | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8594 const size_t left = pointer_delta(fc_addr, freeFinger()); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8595 const size_t right = chunkSize; |
0 | 8596 switch (FLSCoalescePolicy) { |
8597 // numeric value forms a coalition aggressiveness metric | |
8598 case 0: { // never coalesce | |
8599 coalesce = false; | |
8600 break; | |
8601 } | |
8602 case 1: { // coalesce if left & right chunks on overpopulated lists | |
8603 coalesce = _sp->coalOverPopulated(left) && | |
8604 _sp->coalOverPopulated(right); | |
8605 break; | |
8606 } | |
8607 case 2: { // coalesce if left chunk on overpopulated list (default) | |
8608 coalesce = _sp->coalOverPopulated(left); | |
8609 break; | |
8610 } | |
8611 case 3: { // coalesce if left OR right chunk on overpopulated list | |
8612 coalesce = _sp->coalOverPopulated(left) || | |
8613 _sp->coalOverPopulated(right); | |
8614 break; | |
8615 } | |
8616 case 4: { // always coalesce | |
8617 coalesce = true; | |
8618 break; | |
8619 } | |
8620 default: | |
8621 ShouldNotReachHere(); | |
8622 } | |
8623 | |
8624 // Should the current free range be coalesced? | |
8625 // If the chunk is in a free range and either we decided to coalesce above | |
8626 // or the chunk is near the large block at the end of the heap | |
8627 // (isNearLargestChunk() returns true), then coalesce this chunk. | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8628 const bool doCoalesce = inFreeRange() |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8629 && (coalesce || _g->isNearLargestChunk(fc_addr)); |
0 | 8630 if (doCoalesce) { |
8631 // Coalesce the current free range on the left with the new | |
8632 // chunk on the right. If either is on a free list, | |
8633 // it must be removed from the list and stashed in the closure. | |
8634 if (freeRangeInFreeLists()) { | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8635 FreeChunk* const ffc = (FreeChunk*)freeFinger(); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8636 assert(ffc->size() == pointer_delta(fc_addr, freeFinger()), |
0 | 8637 "Size of free range is inconsistent with chunk size."); |
8638 if (CMSTestInFreeList) { | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8639 assert(_sp->verify_chunk_in_free_list(ffc), |
0 | 8640 "Chunk is not in free lists"); |
8641 } | |
8642 _sp->coalDeath(ffc->size()); | |
8643 _sp->removeFreeChunkFromFreeLists(ffc); | |
8644 set_freeRangeInFreeLists(false); | |
8645 } | |
8646 if (fcInFreeLists) { | |
8647 _sp->coalDeath(chunkSize); | |
8648 assert(fc->size() == chunkSize, | |
8649 "The chunk has the wrong size or is not in the free lists"); | |
8650 _sp->removeFreeChunkFromFreeLists(fc); | |
8651 } | |
8652 set_lastFreeRangeCoalesced(true); | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8653 print_free_block_coalesced(fc); |
0 | 8654 } else { // not in a free range and/or should not coalesce |
8655 // Return the current free range and start a new one. | |
8656 if (inFreeRange()) { | |
8657 // In a free range but cannot coalesce with the right hand chunk. | |
8658 // Put the current free range into the free lists. | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8659 flush_cur_free_chunk(freeFinger(), |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8660 pointer_delta(fc_addr, freeFinger())); |
0 | 8661 } |
8662 // Set up for new free range. Pass along whether the right hand | |
8663 // chunk is in the free lists. | |
8664 initialize_free_range((HeapWord*)fc, fcInFreeLists); | |
8665 } | |
8666 } | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8667 |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8668 // Lookahead flush: |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8669 // If we are tracking a free range, and this is the last chunk that |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8670 // we'll look at because its end crosses past _limit, we'll preemptively |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8671 // flush it along with any free range we may be holding on to. Note that |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8672 // this can be the case only for an already free or freshly garbage |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8673 // chunk. If this block is an object, it can never straddle |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8674 // over _limit. The "straddling" occurs when _limit is set at |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8675 // the previous end of the space when this cycle started, and |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8676 // a subsequent heap expansion caused the previously co-terminal |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8677 // free block to be coalesced with the newly expanded portion, |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8678 // thus rendering _limit a non-block-boundary making it dangerous |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8679 // for the sweeper to step over and examine. |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8680 void SweepClosure::lookahead_and_flush(FreeChunk* fc, size_t chunk_size) { |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8681 assert(inFreeRange(), "Should only be called if currently in a free range."); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8682 HeapWord* const eob = ((HeapWord*)fc) + chunk_size; |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8683 assert(_sp->used_region().contains(eob - 1), |
12112
1bb10d3170fa
8022817: CMS should not shrink if compaction was not done
jmasa
parents:
12088
diff
changeset
|
8684 err_msg("eob = " PTR_FORMAT " eob-1 = " PTR_FORMAT " _limit = " PTR_FORMAT |
1bb10d3170fa
8022817: CMS should not shrink if compaction was not done
jmasa
parents:
12088
diff
changeset
|
8685 " out of bounds wrt _sp = [" PTR_FORMAT "," PTR_FORMAT ")" |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8686 " when examining fc = " PTR_FORMAT "(" SIZE_FORMAT ")", |
12112
1bb10d3170fa
8022817: CMS should not shrink if compaction was not done
jmasa
parents:
12088
diff
changeset
|
8687 eob, eob-1, _limit, _sp->bottom(), _sp->end(), fc, chunk_size)); |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8688 if (eob >= _limit) { |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8689 assert(eob == _limit || fc->is_free(), "Only a free chunk should allow us to cross over the limit"); |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8690 if (CMSTraceSweeper) { |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8691 gclog_or_tty->print_cr("_limit " PTR_FORMAT " reached or crossed by block " |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8692 "[" PTR_FORMAT "," PTR_FORMAT ") in space " |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8693 "[" PTR_FORMAT "," PTR_FORMAT ")", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8694 _limit, fc, eob, _sp->bottom(), _sp->end()); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8695 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8696 // Return the storage we are tracking back into the free lists. |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8697 if (CMSTraceSweeper) { |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8698 gclog_or_tty->print_cr("Flushing ... "); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8699 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8700 assert(freeFinger() < eob, "Error"); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8701 flush_cur_free_chunk( freeFinger(), pointer_delta(eob, freeFinger())); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8702 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8703 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8704 |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8705 void SweepClosure::flush_cur_free_chunk(HeapWord* chunk, size_t size) { |
0 | 8706 assert(inFreeRange(), "Should only be called if currently in a free range."); |
8707 assert(size > 0, | |
8708 "A zero sized chunk cannot be added to the free lists."); | |
8709 if (!freeRangeInFreeLists()) { | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8710 if (CMSTestInFreeList) { |
0 | 8711 FreeChunk* fc = (FreeChunk*) chunk; |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8712 fc->set_size(size); |
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8713 assert(!_sp->verify_chunk_in_free_list(fc), |
0 | 8714 "chunk should not be in free lists yet"); |
8715 } | |
8716 if (CMSTraceSweeper) { | |
8717 gclog_or_tty->print_cr(" -- add free block 0x%x (%d) to free lists", | |
8718 chunk, size); | |
8719 } | |
8720 // A new free range is going to be starting. The current | |
8721 // free range has not been added to the free lists yet or | |
8722 // was removed so add it back. | |
8723 // If the current free range was coalesced, then the death | |
8724 // of the free range was recorded. Record a birth now. | |
8725 if (lastFreeRangeCoalesced()) { | |
8726 _sp->coalBirth(size); | |
8727 } | |
8728 _sp->addChunkAndRepairOffsetTable(chunk, size, | |
8729 lastFreeRangeCoalesced()); | |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8730 } else if (CMSTraceSweeper) { |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8731 gclog_or_tty->print_cr("Already in free list: nothing to flush"); |
0 | 8732 } |
8733 set_inFreeRange(false); | |
8734 set_freeRangeInFreeLists(false); | |
8735 } | |
8736 | |
8737 // We take a break if we've been at this for a while, | |
8738 // so as to avoid monopolizing the locks involved. | |
8739 void SweepClosure::do_yield_work(HeapWord* addr) { | |
8740 // Return current free chunk being used for coalescing (if any) | |
8741 // to the appropriate freelist. After yielding, the next | |
8742 // free block encountered will start a coalescing range of | |
8743 // free blocks. If the next free block is adjacent to the | |
8744 // chunk just flushed, they will need to wait for the next | |
8745 // sweep to be coalesced. | |
8746 if (inFreeRange()) { | |
2132
4947ee68d19c
7008136: CMS: assert((HeapWord*)nextChunk <= _limit) failed: sweep invariant
ysr
parents:
1994
diff
changeset
|
8747 flush_cur_free_chunk(freeFinger(), pointer_delta(addr, freeFinger())); |
0 | 8748 } |
8749 | |
8750 // First give up the locks, then yield, then re-lock. | |
8751 // We should probably use a constructor/destructor idiom to | |
8752 // do this unlock/lock or modify the MutexUnlocker class to | |
8753 // serve our purpose. XXX | |
8754 assert_lock_strong(_bitMap->lock()); | |
8755 assert_lock_strong(_freelistLock); | |
8756 assert(ConcurrentMarkSweepThread::cms_thread_has_cms_token(), | |
8757 "CMS thread should hold CMS token"); | |
8758 _bitMap->lock()->unlock(); | |
8759 _freelistLock->unlock(); | |
8760 ConcurrentMarkSweepThread::desynchronize(true); | |
8761 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
8762 _collector->stopTimer(); | |
8763 GCPauseTimer p(_collector->size_policy()->concurrent_timer_ptr()); | |
8764 if (PrintCMSStatistics != 0) { | |
8765 _collector->incrementYields(); | |
8766 } | |
8767 _collector->icms_wait(); | |
8768 | |
8769 // See the comment in coordinator_yield() | |
8770 for (unsigned i = 0; i < CMSYieldSleepCount && | |
8771 ConcurrentMarkSweepThread::should_yield() && | |
8772 !CMSCollector::foregroundGCIsActive(); ++i) { | |
8773 os::sleep(Thread::current(), 1, false); | |
8774 ConcurrentMarkSweepThread::acknowledge_yield_request(); | |
8775 } | |
8776 | |
8777 ConcurrentMarkSweepThread::synchronize(true); | |
8778 _freelistLock->lock(); | |
8779 _bitMap->lock()->lock_without_safepoint_check(); | |
8780 _collector->startTimer(); | |
8781 } | |
8782 | |
8783 #ifndef PRODUCT | |
8784 // This is actually very useful in a product build if it can | |
8785 // be called from the debugger. Compile it into the product | |
8786 // as needed. | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8787 bool debug_verify_chunk_in_free_list(FreeChunk* fc) { |
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
8788 return debug_cms_space->verify_chunk_in_free_list(fc); |
0 | 8789 } |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8790 #endif |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8791 |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8792 void SweepClosure::print_free_block_coalesced(FreeChunk* fc) const { |
0 | 8793 if (CMSTraceSweeper) { |
3746
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8794 gclog_or_tty->print_cr("Sweep:coal_free_blk " PTR_FORMAT " (" SIZE_FORMAT ")", |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8795 fc, fc->size()); |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8796 } |
537a4053b0f9
7042740: CMS: assert(n> q) failed: Looping at: ... blockOffsetTable.cpp:557
ysr
parents:
3356
diff
changeset
|
8797 } |
0 | 8798 |
8799 // CMSIsAliveClosure | |
8800 bool CMSIsAliveClosure::do_object_b(oop obj) { | |
8801 HeapWord* addr = (HeapWord*)obj; | |
8802 return addr != NULL && | |
8803 (!_span.contains(addr) || _bit_map->isMarked(addr)); | |
8804 } | |
8805 | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
8806 |
935 | 8807 CMSKeepAliveClosure::CMSKeepAliveClosure( CMSCollector* collector, |
8808 MemRegion span, | |
8809 CMSBitMap* bit_map, CMSMarkStack* mark_stack, | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
8810 bool cpc): |
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
8811 _collector(collector), |
935 | 8812 _span(span), |
8813 _bit_map(bit_map), | |
8814 _mark_stack(mark_stack), | |
8815 _concurrent_precleaning(cpc) { | |
8816 assert(!_span.is_empty(), "Empty span could spell trouble"); | |
8817 } | |
8818 | |
8819 | |
0 | 8820 // CMSKeepAliveClosure: the serial version |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8821 void CMSKeepAliveClosure::do_oop(oop obj) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8822 HeapWord* addr = (HeapWord*)obj; |
0 | 8823 if (_span.contains(addr) && |
8824 !_bit_map->isMarked(addr)) { | |
8825 _bit_map->mark(addr); | |
8826 bool simulate_overflow = false; | |
8827 NOT_PRODUCT( | |
8828 if (CMSMarkStackOverflowALot && | |
8829 _collector->simulate_overflow()) { | |
8830 // simulate a stack overflow | |
8831 simulate_overflow = true; | |
8832 } | |
8833 ) | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8834 if (simulate_overflow || !_mark_stack->push(obj)) { |
452
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8835 if (_concurrent_precleaning) { |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8836 // We dirty the overflown object and let the remark |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8837 // phase deal with it. |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8838 assert(_collector->overflow_list_is_empty(), "Error"); |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8839 // In the case of object arrays, we need to dirty all of |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8840 // the cards that the object spans. No locking or atomics |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8841 // are needed since no one else can be mutating the mod union |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8842 // table. |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8843 if (obj->is_objArray()) { |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8844 size_t sz = obj->size(); |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8845 HeapWord* end_card_addr = |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8846 (HeapWord*)round_to((intptr_t)(addr+sz), CardTableModRefBS::card_size); |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8847 MemRegion redirty_range = MemRegion(addr, end_card_addr); |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8848 assert(!redirty_range.is_empty(), "Arithmetical tautology"); |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8849 _collector->_modUnionTable.mark_range(redirty_range); |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8850 } else { |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8851 _collector->_modUnionTable.mark(addr); |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8852 } |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8853 _collector->_ser_kac_preclean_ovflw++; |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8854 } else { |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8855 _collector->push_on_overflow_list(obj); |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8856 _collector->_ser_kac_ovflw++; |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8857 } |
0 | 8858 } |
8859 } | |
8860 } | |
8861 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8862 void CMSKeepAliveClosure::do_oop(oop* p) { CMSKeepAliveClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8863 void CMSKeepAliveClosure::do_oop(narrowOop* p) { CMSKeepAliveClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8864 |
0 | 8865 // CMSParKeepAliveClosure: a parallel version of the above. |
8866 // The work queues are private to each closure (thread), | |
8867 // but (may be) available for stealing by other threads. | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8868 void CMSParKeepAliveClosure::do_oop(oop obj) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8869 HeapWord* addr = (HeapWord*)obj; |
0 | 8870 if (_span.contains(addr) && |
8871 !_bit_map->isMarked(addr)) { | |
8872 // In general, during recursive tracing, several threads | |
8873 // may be concurrently getting here; the first one to | |
8874 // "tag" it, claims it. | |
8875 if (_bit_map->par_mark(addr)) { | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8876 bool res = _work_queue->push(obj); |
0 | 8877 assert(res, "Low water mark should be much less than capacity"); |
8878 // Do a recursive trim in the hope that this will keep | |
8879 // stack usage lower, but leave some oops for potential stealers | |
8880 trim_queue(_low_water_mark); | |
8881 } // Else, another thread got there first | |
8882 } | |
8883 } | |
8884 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8885 void CMSParKeepAliveClosure::do_oop(oop* p) { CMSParKeepAliveClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8886 void CMSParKeepAliveClosure::do_oop(narrowOop* p) { CMSParKeepAliveClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8887 |
0 | 8888 void CMSParKeepAliveClosure::trim_queue(uint max) { |
8889 while (_work_queue->size() > max) { | |
8890 oop new_oop; | |
8891 if (_work_queue->pop_local(new_oop)) { | |
8892 assert(new_oop != NULL && new_oop->is_oop(), "Expected an oop"); | |
8893 assert(_bit_map->isMarked((HeapWord*)new_oop), | |
8894 "no white objects on this stack!"); | |
8895 assert(_span.contains((HeapWord*)new_oop), "Out of bounds oop"); | |
8896 // iterate over the oops in this oop, marking and pushing | |
8897 // the ones in CMS heap (i.e. in _span). | |
8898 new_oop->oop_iterate(&_mark_and_push); | |
8899 } | |
8900 } | |
8901 } | |
8902 | |
935 | 8903 CMSInnerParMarkAndPushClosure::CMSInnerParMarkAndPushClosure( |
8904 CMSCollector* collector, | |
8905 MemRegion span, CMSBitMap* bit_map, | |
8906 OopTaskQueue* work_queue): | |
6725
da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
coleenp
parents:
6197
diff
changeset
|
8907 _collector(collector), |
935 | 8908 _span(span), |
8909 _bit_map(bit_map), | |
8910 _work_queue(work_queue) { } | |
8911 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8912 void CMSInnerParMarkAndPushClosure::do_oop(oop obj) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8913 HeapWord* addr = (HeapWord*)obj; |
0 | 8914 if (_span.contains(addr) && |
8915 !_bit_map->isMarked(addr)) { | |
8916 if (_bit_map->par_mark(addr)) { | |
8917 bool simulate_overflow = false; | |
8918 NOT_PRODUCT( | |
8919 if (CMSMarkStackOverflowALot && | |
8920 _collector->par_simulate_overflow()) { | |
8921 // simulate a stack overflow | |
8922 simulate_overflow = true; | |
8923 } | |
8924 ) | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8925 if (simulate_overflow || !_work_queue->push(obj)) { |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8926 _collector->par_push_on_overflow_list(obj); |
0 | 8927 _collector->_par_kac_ovflw++; |
8928 } | |
8929 } // Else another thread got there already | |
8930 } | |
8931 } | |
8932 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8933 void CMSInnerParMarkAndPushClosure::do_oop(oop* p) { CMSInnerParMarkAndPushClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8934 void CMSInnerParMarkAndPushClosure::do_oop(narrowOop* p) { CMSInnerParMarkAndPushClosure::do_oop_work(p); } |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8935 |
0 | 8936 ////////////////////////////////////////////////////////////////// |
8937 // CMSExpansionCause ///////////////////////////// | |
8938 ////////////////////////////////////////////////////////////////// | |
8939 const char* CMSExpansionCause::to_string(CMSExpansionCause::Cause cause) { | |
8940 switch (cause) { | |
8941 case _no_expansion: | |
8942 return "No expansion"; | |
8943 case _satisfy_free_ratio: | |
8944 return "Free ratio"; | |
8945 case _satisfy_promotion: | |
8946 return "Satisfy promotion"; | |
8947 case _satisfy_allocation: | |
8948 return "allocation"; | |
8949 case _allocate_par_lab: | |
8950 return "Par LAB"; | |
8951 case _allocate_par_spooling_space: | |
8952 return "Par Spooling Space"; | |
8953 case _adaptive_size_policy: | |
8954 return "Ergonomics"; | |
8955 default: | |
8956 return "unknown"; | |
8957 } | |
8958 } | |
8959 | |
8960 void CMSDrainMarkingStackClosure::do_void() { | |
8961 // the max number to take from overflow list at a time | |
8962 const size_t num = _mark_stack->capacity()/4; | |
452
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8963 assert(!_concurrent_precleaning || _collector->overflow_list_is_empty(), |
00b023ae2d78
6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents:
360
diff
changeset
|
8964 "Overflow list should be NULL during concurrent phases"); |
0 | 8965 while (!_mark_stack->isEmpty() || |
8966 // if stack is empty, check the overflow list | |
8967 _collector->take_from_overflow_list(num, _mark_stack)) { | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8968 oop obj = _mark_stack->pop(); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8969 HeapWord* addr = (HeapWord*)obj; |
0 | 8970 assert(_span.contains(addr), "Should be within span"); |
8971 assert(_bit_map->isMarked(addr), "Should be marked"); | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8972 assert(obj->is_oop(), "Should be an oop"); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
94
diff
changeset
|
8973 obj->oop_iterate(_keep_alive); |
0 | 8974 } |
8975 } | |
8976 | |
8977 void CMSParDrainMarkingStackClosure::do_void() { | |
8978 // drain queue | |
8979 trim_queue(0); | |
8980 } | |
8981 | |
8982 // Trim our work_queue so its length is below max at return | |
8983 void CMSParDrainMarkingStackClosure::trim_queue(uint max) { | |
8984 while (_work_queue->size() > max) { | |
8985 oop new_oop; | |
8986 if (_work_queue->pop_local(new_oop)) { | |
8987 assert(new_oop->is_oop(), "Expected an oop"); | |
8988 assert(_bit_map->isMarked((HeapWord*)new_oop), | |
8989 "no white objects on this stack!"); | |
8990 assert(_span.contains((HeapWord*)new_oop), "Out of bounds oop"); | |
8991 // iterate over the oops in this oop, marking and pushing | |
8992 // the ones in CMS heap (i.e. in _span). | |
8993 new_oop->oop_iterate(&_mark_and_push); | |
8994 } | |
8995 } | |
8996 } | |
8997 | |
8998 //////////////////////////////////////////////////////////////////// | |
8999 // Support for Marking Stack Overflow list handling and related code | |
9000 //////////////////////////////////////////////////////////////////// | |
9001 // Much of the following code is similar in shape and spirit to the | |
9002 // code used in ParNewGC. We should try and share that code | |
9003 // as much as possible in the future. | |
9004 | |
9005 #ifndef PRODUCT | |
9006 // Debugging support for CMSStackOverflowALot | |
9007 | |
9008 // It's OK to call this multi-threaded; the worst thing | |
9009 // that can happen is that we'll get a bunch of closely | |
14309 | 9010 // spaced simulated overflows, but that's OK, in fact |
0 | 9011 // probably good as it would exercise the overflow code |
9012 // under contention. | |
9013 bool CMSCollector::simulate_overflow() { | |
9014 if (_overflow_counter-- <= 0) { // just being defensive | |
9015 _overflow_counter = CMSMarkStackOverflowInterval; | |
9016 return true; | |
9017 } else { | |
9018 return false; | |
9019 } | |
9020 } | |
9021 | |
9022 bool CMSCollector::par_simulate_overflow() { | |
9023 return simulate_overflow(); | |
9024 } | |
9025 #endif | |
9026 | |
9027 // Single-threaded | |
9028 bool CMSCollector::take_from_overflow_list(size_t num, CMSMarkStack* stack) { | |
9029 assert(stack->isEmpty(), "Expected precondition"); | |
9030 assert(stack->capacity() > num, "Shouldn't bite more than can chew"); | |
9031 size_t i = num; | |
9032 oop cur = _overflow_list; | |
9033 const markOop proto = markOopDesc::prototype(); | |
534 | 9034 NOT_PRODUCT(ssize_t n = 0;) |
0 | 9035 for (oop next; i > 0 && cur != NULL; cur = next, i--) { |
9036 next = oop(cur->mark()); | |
9037 cur->set_mark(proto); // until proven otherwise | |
9038 assert(cur->is_oop(), "Should be an oop"); | |
9039 bool res = stack->push(cur); | |
9040 assert(res, "Bit off more than can chew?"); | |
9041 NOT_PRODUCT(n++;) | |
9042 } | |
9043 _overflow_list = cur; | |
9044 #ifndef PRODUCT | |
9045 assert(_num_par_pushes >= n, "Too many pops?"); | |
9046 _num_par_pushes -=n; | |
9047 #endif | |
9048 return !stack->isEmpty(); | |
9049 } | |
9050 | |
12316
190899198332
7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents:
12226
diff
changeset
|
9051 #define BUSY (cast_to_oop<intptr_t>(0x1aff1aff)) |
534 | 9052 // (MT-safe) Get a prefix of at most "num" from the list. |
9053 // The overflow list is chained through the mark word of | |
9054 // each object in the list. We fetch the entire list, | |
9055 // break off a prefix of the right size and return the | |
9056 // remainder. If other threads try to take objects from | |
9057 // the overflow list at that time, they will wait for | |
9058 // some time to see if data becomes available. If (and | |
9059 // only if) another thread places one or more object(s) | |
9060 // on the global list before we have returned the suffix | |
9061 // to the global list, we will walk down our local list | |
9062 // to find its end and append the global list to | |
9063 // our suffix before returning it. This suffix walk can | |
9064 // prove to be expensive (quadratic in the amount of traffic) | |
9065 // when there are many objects in the overflow list and | |
9066 // there is much producer-consumer contention on the list. | |
9067 // *NOTE*: The overflow list manipulation code here and | |
9068 // in ParNewGeneration:: are very similar in shape, | |
9069 // except that in the ParNew case we use the old (from/eden) | |
9070 // copy of the object to thread the list via its klass word. | |
9071 // Because of the common code, if you make any changes in | |
9072 // the code below, please check the ParNew version to see if | |
9073 // similar changes might be needed. | |
9074 // CR 6797058 has been filed to consolidate the common code. | |
0 | 9075 bool CMSCollector::par_take_from_overflow_list(size_t num, |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
9076 OopTaskQueue* work_q, |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
9077 int no_of_gc_threads) { |
534 | 9078 assert(work_q->size() == 0, "First empty local work queue"); |
0 | 9079 assert(num < work_q->max_elems(), "Can't bite more than we can chew"); |
9080 if (_overflow_list == NULL) { | |
9081 return false; | |
9082 } | |
9083 // Grab the entire list; we'll put back a suffix | |
12316
190899198332
7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents:
12226
diff
changeset
|
9084 oop prefix = cast_to_oop(Atomic::xchg_ptr(BUSY, &_overflow_list)); |
534 | 9085 Thread* tid = Thread::current(); |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
9086 // Before "no_of_gc_threads" was introduced CMSOverflowSpinCount was |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
9087 // set to ParallelGCThreads. |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1777
diff
changeset
|
9088 size_t CMSOverflowSpinCount = (size_t) no_of_gc_threads; // was ParallelGCThreads; |
534 | 9089 size_t sleep_time_millis = MAX2((size_t)1, num/100); |
9090 // If the list is busy, we spin for a short while, | |
9091 // sleeping between attempts to get the list. | |
9092 for (size_t spin = 0; prefix == BUSY && spin < CMSOverflowSpinCount; spin++) { | |
9093 os::sleep(tid, sleep_time_millis, false); | |
9094 if (_overflow_list == NULL) { | |
9095 // Nothing left to take | |
9096 return false; | |
9097 } else if (_overflow_list != BUSY) { | |
9098 // Try and grab the prefix | |
12316
190899198332
7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents:
12226
diff
changeset
|
9099 prefix = cast_to_oop(Atomic::xchg_ptr(BUSY, &_overflow_list)); |
534 | 9100 } |
9101 } | |
9102 // If the list was found to be empty, or we spun long | |
9103 // enough, we give up and return empty-handed. If we leave | |
9104 // the list in the BUSY state below, it must be the case that | |
9105 // some other thread holds the overflow list and will set it | |
9106 // to a non-BUSY state in the future. | |
9107 if (prefix == NULL || prefix == BUSY) { | |
9108 // Nothing to take or waited long enough | |
9109 if (prefix == NULL) { | |
9110 // Write back the NULL in case we overwrote it with BUSY above | |
9111 // and it is still the same value. | |
9112 (void) Atomic::cmpxchg_ptr(NULL, &_overflow_list, BUSY); | |
9113 } | |
9114 return false; | |
9115 } | |
9116 assert(prefix != NULL && prefix != BUSY, "Error"); | |
0 | 9117 size_t i = num; |
9118 oop cur = prefix; | |
534 | 9119 // Walk down the first "num" objects, unless we reach the end. |
0 | 9120 for (; i > 1 && cur->mark() != NULL; cur = oop(cur->mark()), i--); |
534 | 9121 if (cur->mark() == NULL) { |
9122 // We have "num" or fewer elements in the list, so there | |
9123 // is nothing to return to the global list. | |
9124 // Write back the NULL in lieu of the BUSY we wrote | |
9125 // above, if it is still the same value. | |
9126 if (_overflow_list == BUSY) { | |
9127 (void) Atomic::cmpxchg_ptr(NULL, &_overflow_list, BUSY); | |
9128 } | |
9129 } else { | |
14309 | 9130 // Chop off the suffix and return it to the global list. |
534 | 9131 assert(cur->mark() != BUSY, "Error"); |
0 | 9132 oop suffix_head = cur->mark(); // suffix will be put back on global list |
9133 cur->set_mark(NULL); // break off suffix | |
534 | 9134 // It's possible that the list is still in the empty(busy) state |
9135 // we left it in a short while ago; in that case we may be | |
9136 // able to place back the suffix without incurring the cost | |
9137 // of a walk down the list. | |
0 | 9138 oop observed_overflow_list = _overflow_list; |
534 | 9139 oop cur_overflow_list = observed_overflow_list; |
9140 bool attached = false; | |
9141 while (observed_overflow_list == BUSY || observed_overflow_list == NULL) { | |
0 | 9142 observed_overflow_list = |
534 | 9143 (oop) Atomic::cmpxchg_ptr(suffix_head, &_overflow_list, cur_overflow_list); |
9144 if (cur_overflow_list == observed_overflow_list) { | |
9145 attached = true; | |
9146 break; | |
9147 } else cur_overflow_list = observed_overflow_list; | |
9148 } | |
9149 if (!attached) { | |
9150 // Too bad, someone else sneaked in (at least) an element; we'll need | |
9151 // to do a splice. Find tail of suffix so we can prepend suffix to global | |
9152 // list. | |
9153 for (cur = suffix_head; cur->mark() != NULL; cur = (oop)(cur->mark())); | |
9154 oop suffix_tail = cur; | |
9155 assert(suffix_tail != NULL && suffix_tail->mark() == NULL, | |
9156 "Tautology"); | |
9157 observed_overflow_list = _overflow_list; | |
9158 do { | |
9159 cur_overflow_list = observed_overflow_list; | |
9160 if (cur_overflow_list != BUSY) { | |
9161 // Do the splice ... | |
9162 suffix_tail->set_mark(markOop(cur_overflow_list)); | |
9163 } else { // cur_overflow_list == BUSY | |
9164 suffix_tail->set_mark(NULL); | |
9165 } | |
9166 // ... and try to place spliced list back on overflow_list ... | |
9167 observed_overflow_list = | |
9168 (oop) Atomic::cmpxchg_ptr(suffix_head, &_overflow_list, cur_overflow_list); | |
9169 } while (cur_overflow_list != observed_overflow_list); | |
9170 // ... until we have succeeded in doing so. | |
9171 } | |
0 | 9172 } |
9173 | |
9174 // Push the prefix elements on work_q | |
9175 assert(prefix != NULL, "control point invariant"); | |
9176 const markOop proto = markOopDesc::prototype(); | |
9177 oop next; | |
534 | 9178 NOT_PRODUCT(ssize_t n = 0;) |
0 | 9179 for (cur = prefix; cur != NULL; cur = next) { |
9180 next = oop(cur->mark()); | |
9181 cur->set_mark(proto); // until proven otherwise | |
9182 assert(cur->is_oop(), "Should be an oop"); | |
9183 bool res = work_q->push(cur); | |
9184 assert(res, "Bit off more than we can chew?"); | |
9185 NOT_PRODUCT(n++;) | |
9186 } | |
9187 #ifndef PRODUCT | |
9188 assert(_num_par_pushes >= n, "Too many pops?"); | |
9189 Atomic::add_ptr(-(intptr_t)n, &_num_par_pushes); | |
9190 #endif | |
9191 return true; | |
9192 } | |
9193 | |
9194 // Single-threaded | |
9195 void CMSCollector::push_on_overflow_list(oop p) { | |
9196 NOT_PRODUCT(_num_par_pushes++;) | |
9197 assert(p->is_oop(), "Not an oop"); | |
9198 preserve_mark_if_necessary(p); | |
9199 p->set_mark((markOop)_overflow_list); | |
9200 _overflow_list = p; | |
9201 } | |
9202 | |
9203 // Multi-threaded; use CAS to prepend to overflow list | |
9204 void CMSCollector::par_push_on_overflow_list(oop p) { | |
9205 NOT_PRODUCT(Atomic::inc_ptr(&_num_par_pushes);) | |
9206 assert(p->is_oop(), "Not an oop"); | |
9207 par_preserve_mark_if_necessary(p); | |
9208 oop observed_overflow_list = _overflow_list; | |
9209 oop cur_overflow_list; | |
9210 do { | |
9211 cur_overflow_list = observed_overflow_list; | |
534 | 9212 if (cur_overflow_list != BUSY) { |
9213 p->set_mark(markOop(cur_overflow_list)); | |
9214 } else { | |
9215 p->set_mark(NULL); | |
9216 } | |
0 | 9217 observed_overflow_list = |
9218 (oop) Atomic::cmpxchg_ptr(p, &_overflow_list, cur_overflow_list); | |
9219 } while (cur_overflow_list != observed_overflow_list); | |
9220 } | |
534 | 9221 #undef BUSY |
0 | 9222 |
9223 // Single threaded | |
9224 // General Note on GrowableArray: pushes may silently fail | |
9225 // because we are (temporarily) out of C-heap for expanding | |
9226 // the stack. The problem is quite ubiquitous and affects | |
9227 // a lot of code in the JVM. The prudent thing for GrowableArray | |
9228 // to do (for now) is to exit with an error. However, that may | |
9229 // be too draconian in some cases because the caller may be | |
534 | 9230 // able to recover without much harm. For such cases, we |
0 | 9231 // should probably introduce a "soft_push" method which returns |
9232 // an indication of success or failure with the assumption that | |
9233 // the caller may be able to recover from a failure; code in | |
9234 // the VM can then be changed, incrementally, to deal with such | |
9235 // failures where possible, thus, incrementally hardening the VM | |
9236 // in such low resource situations. | |
9237 void CMSCollector::preserve_mark_work(oop p, markOop m) { | |
1836
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9238 _preserved_oop_stack.push(p); |
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9239 _preserved_mark_stack.push(m); |
0 | 9240 assert(m == p->mark(), "Mark word changed"); |
1836
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9241 assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(), |
0 | 9242 "bijection"); |
9243 } | |
9244 | |
9245 // Single threaded | |
9246 void CMSCollector::preserve_mark_if_necessary(oop p) { | |
9247 markOop m = p->mark(); | |
9248 if (m->must_be_preserved(p)) { | |
9249 preserve_mark_work(p, m); | |
9250 } | |
9251 } | |
9252 | |
9253 void CMSCollector::par_preserve_mark_if_necessary(oop p) { | |
9254 markOop m = p->mark(); | |
9255 if (m->must_be_preserved(p)) { | |
9256 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); | |
9257 // Even though we read the mark word without holding | |
9258 // the lock, we are assured that it will not change | |
9259 // because we "own" this oop, so no other thread can | |
9260 // be trying to push it on the overflow list; see | |
9261 // the assertion in preserve_mark_work() that checks | |
9262 // that m == p->mark(). | |
9263 preserve_mark_work(p, m); | |
9264 } | |
9265 } | |
9266 | |
9267 // We should be able to do this multi-threaded, | |
9268 // a chunk of stack being a task (this is | |
9269 // correct because each oop only ever appears | |
9270 // once in the overflow list. However, it's | |
9271 // not very easy to completely overlap this with | |
9272 // other operations, so will generally not be done | |
9273 // until all work's been completed. Because we | |
9274 // expect the preserved oop stack (set) to be small, | |
9275 // it's probably fine to do this single-threaded. | |
9276 // We can explore cleverer concurrent/overlapped/parallel | |
9277 // processing of preserved marks if we feel the | |
9278 // need for this in the future. Stack overflow should | |
9279 // be so rare in practice and, when it happens, its | |
9280 // effect on performance so great that this will | |
9281 // likely just be in the noise anyway. | |
9282 void CMSCollector::restore_preserved_marks_if_any() { | |
9283 assert(SafepointSynchronize::is_at_safepoint(), | |
9284 "world should be stopped"); | |
9285 assert(Thread::current()->is_ConcurrentGC_thread() || | |
9286 Thread::current()->is_VM_thread(), | |
9287 "should be single-threaded"); | |
1836
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9288 assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(), |
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9289 "bijection"); |
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9290 |
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9291 while (!_preserved_oop_stack.is_empty()) { |
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9292 oop p = _preserved_oop_stack.pop(); |
0 | 9293 assert(p->is_oop(), "Should be an oop"); |
9294 assert(_span.contains(p), "oop should be in _span"); | |
9295 assert(p->mark() == markOopDesc::prototype(), | |
9296 "Set when taken from overflow list"); | |
1836
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9297 markOop m = _preserved_mark_stack.pop(); |
0 | 9298 p->set_mark(m); |
9299 } | |
1836
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9300 assert(_preserved_mark_stack.is_empty() && _preserved_oop_stack.is_empty(), |
0 | 9301 "stacks were cleared above"); |
9302 } | |
9303 | |
9304 #ifndef PRODUCT | |
9305 bool CMSCollector::no_preserved_marks() const { | |
1836
894b1d7c7e01
6423256: GC stacks should use a better data structure
jcoomes
parents:
1833
diff
changeset
|
9306 return _preserved_mark_stack.is_empty() && _preserved_oop_stack.is_empty(); |
0 | 9307 } |
9308 #endif | |
9309 | |
9310 CMSAdaptiveSizePolicy* ASConcurrentMarkSweepGeneration::cms_size_policy() const | |
9311 { | |
9312 GenCollectedHeap* gch = (GenCollectedHeap*) GenCollectedHeap::heap(); | |
9313 CMSAdaptiveSizePolicy* size_policy = | |
9314 (CMSAdaptiveSizePolicy*) gch->gen_policy()->size_policy(); | |
9315 assert(size_policy->is_gc_cms_adaptive_size_policy(), | |
9316 "Wrong type for size policy"); | |
9317 return size_policy; | |
9318 } | |
9319 | |
9320 void ASConcurrentMarkSweepGeneration::resize(size_t cur_promo_size, | |
9321 size_t desired_promo_size) { | |
9322 if (cur_promo_size < desired_promo_size) { | |
9323 size_t expand_bytes = desired_promo_size - cur_promo_size; | |
9324 if (PrintAdaptiveSizePolicy && Verbose) { | |
9325 gclog_or_tty->print_cr(" ASConcurrentMarkSweepGeneration::resize " | |
9326 "Expanding tenured generation by " SIZE_FORMAT " (bytes)", | |
9327 expand_bytes); | |
9328 } | |
9329 expand(expand_bytes, | |
9330 MinHeapDeltaBytes, | |
9331 CMSExpansionCause::_adaptive_size_policy); | |
9332 } else if (desired_promo_size < cur_promo_size) { | |
9333 size_t shrink_bytes = cur_promo_size - desired_promo_size; | |
9334 if (PrintAdaptiveSizePolicy && Verbose) { | |
9335 gclog_or_tty->print_cr(" ASConcurrentMarkSweepGeneration::resize " | |
9336 "Shrinking tenured generation by " SIZE_FORMAT " (bytes)", | |
9337 shrink_bytes); | |
9338 } | |
9339 shrink(shrink_bytes); | |
9340 } | |
9341 } | |
9342 | |
9343 CMSGCAdaptivePolicyCounters* ASConcurrentMarkSweepGeneration::gc_adaptive_policy_counters() { | |
9344 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
9345 CMSGCAdaptivePolicyCounters* counters = | |
9346 (CMSGCAdaptivePolicyCounters*) gch->collector_policy()->counters(); | |
9347 assert(counters->kind() == GCPolicyCounters::CMSGCAdaptivePolicyCountersKind, | |
9348 "Wrong kind of counters"); | |
9349 return counters; | |
9350 } | |
9351 | |
9352 | |
9353 void ASConcurrentMarkSweepGeneration::update_counters() { | |
9354 if (UsePerfData) { | |
9355 _space_counters->update_all(); | |
9356 _gen_counters->update_all(); | |
9357 CMSGCAdaptivePolicyCounters* counters = gc_adaptive_policy_counters(); | |
9358 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
9359 CMSGCStats* gc_stats_l = (CMSGCStats*) gc_stats(); | |
9360 assert(gc_stats_l->kind() == GCStats::CMSGCStatsKind, | |
9361 "Wrong gc statistics type"); | |
9362 counters->update_counters(gc_stats_l); | |
9363 } | |
9364 } | |
9365 | |
9366 void ASConcurrentMarkSweepGeneration::update_counters(size_t used) { | |
9367 if (UsePerfData) { | |
9368 _space_counters->update_used(used); | |
9369 _space_counters->update_capacity(); | |
9370 _gen_counters->update_all(); | |
9371 | |
9372 CMSGCAdaptivePolicyCounters* counters = gc_adaptive_policy_counters(); | |
9373 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
9374 CMSGCStats* gc_stats_l = (CMSGCStats*) gc_stats(); | |
9375 assert(gc_stats_l->kind() == GCStats::CMSGCStatsKind, | |
9376 "Wrong gc statistics type"); | |
9377 counters->update_counters(gc_stats_l); | |
9378 } | |
9379 } | |
9380 | |
9381 void ASConcurrentMarkSweepGeneration::shrink_by(size_t desired_bytes) { | |
9382 assert_locked_or_safepoint(Heap_lock); | |
9383 assert_lock_strong(freelistLock()); | |
9384 HeapWord* old_end = _cmsSpace->end(); | |
9385 HeapWord* unallocated_start = _cmsSpace->unallocated_block(); | |
9386 assert(old_end >= unallocated_start, "Miscalculation of unallocated_start"); | |
9387 FreeChunk* chunk_at_end = find_chunk_at_end(); | |
9388 if (chunk_at_end == NULL) { | |
9389 // No room to shrink | |
9390 if (PrintGCDetails && Verbose) { | |
9391 gclog_or_tty->print_cr("No room to shrink: old_end " | |
9392 PTR_FORMAT " unallocated_start " PTR_FORMAT | |
9393 " chunk_at_end " PTR_FORMAT, | |
9394 old_end, unallocated_start, chunk_at_end); | |
9395 } | |
9396 return; | |
9397 } else { | |
9398 | |
9399 // Find the chunk at the end of the space and determine | |
9400 // how much it can be shrunk. | |
9401 size_t shrinkable_size_in_bytes = chunk_at_end->size(); | |
9402 size_t aligned_shrinkable_size_in_bytes = | |
9403 align_size_down(shrinkable_size_in_bytes, os::vm_page_size()); | |
6885 | 9404 assert(unallocated_start <= (HeapWord*) chunk_at_end->end(), |
0 | 9405 "Inconsistent chunk at end of space"); |
9406 size_t bytes = MIN2(desired_bytes, aligned_shrinkable_size_in_bytes); | |
9407 size_t word_size_before = heap_word_size(_virtual_space.committed_size()); | |
9408 | |
9409 // Shrink the underlying space | |
9410 _virtual_space.shrink_by(bytes); | |
9411 if (PrintGCDetails && Verbose) { | |
9412 gclog_or_tty->print_cr("ConcurrentMarkSweepGeneration::shrink_by:" | |
9413 " desired_bytes " SIZE_FORMAT | |
9414 " shrinkable_size_in_bytes " SIZE_FORMAT | |
9415 " aligned_shrinkable_size_in_bytes " SIZE_FORMAT | |
9416 " bytes " SIZE_FORMAT, | |
9417 desired_bytes, shrinkable_size_in_bytes, | |
9418 aligned_shrinkable_size_in_bytes, bytes); | |
9419 gclog_or_tty->print_cr(" old_end " SIZE_FORMAT | |
9420 " unallocated_start " SIZE_FORMAT, | |
9421 old_end, unallocated_start); | |
9422 } | |
9423 | |
9424 // If the space did shrink (shrinking is not guaranteed), | |
9425 // shrink the chunk at the end by the appropriate amount. | |
9426 if (((HeapWord*)_virtual_space.high()) < old_end) { | |
9427 size_t new_word_size = | |
9428 heap_word_size(_virtual_space.committed_size()); | |
9429 | |
9430 // Have to remove the chunk from the dictionary because it is changing | |
9431 // size and might be someplace elsewhere in the dictionary. | |
9432 | |
9433 // Get the chunk at end, shrink it, and put it | |
9434 // back. | |
9435 _cmsSpace->removeChunkFromDictionary(chunk_at_end); | |
9436 size_t word_size_change = word_size_before - new_word_size; | |
9437 size_t chunk_at_end_old_size = chunk_at_end->size(); | |
9438 assert(chunk_at_end_old_size >= word_size_change, | |
9439 "Shrink is too large"); | |
6028
f69a5d43dc19
7164144: Fix variable naming style in freeBlockDictionary.* and binaryTreeDictionary*
jmasa
parents:
6026
diff
changeset
|
9440 chunk_at_end->set_size(chunk_at_end_old_size - |
0 | 9441 word_size_change); |
9442 _cmsSpace->freed((HeapWord*) chunk_at_end->end(), | |
9443 word_size_change); | |
9444 | |
9445 _cmsSpace->returnChunkToDictionary(chunk_at_end); | |
9446 | |
9447 MemRegion mr(_cmsSpace->bottom(), new_word_size); | |
9448 _bts->resize(new_word_size); // resize the block offset shared array | |
9449 Universe::heap()->barrier_set()->resize_covered_region(mr); | |
9450 _cmsSpace->assert_locked(); | |
9451 _cmsSpace->set_end((HeapWord*)_virtual_space.high()); | |
9452 | |
9453 NOT_PRODUCT(_cmsSpace->dictionary()->verify()); | |
9454 | |
9455 // update the space and generation capacity counters | |
9456 if (UsePerfData) { | |
9457 _space_counters->update_capacity(); | |
9458 _gen_counters->update_all(); | |
9459 } | |
9460 | |
9461 if (Verbose && PrintGCDetails) { | |
9462 size_t new_mem_size = _virtual_space.committed_size(); | |
9463 size_t old_mem_size = new_mem_size + bytes; | |
7623
203f64878aab
7102489: RFE: cleanup jlong typedef on __APPLE__and _LLP64 systems.
hseigel
parents:
6885
diff
changeset
|
9464 gclog_or_tty->print_cr("Shrinking %s from " SIZE_FORMAT "K by " SIZE_FORMAT "K to " SIZE_FORMAT "K", |
0 | 9465 name(), old_mem_size/K, bytes/K, new_mem_size/K); |
9466 } | |
9467 } | |
9468 | |
9469 assert(_cmsSpace->unallocated_block() <= _cmsSpace->end(), | |
9470 "Inconsistency at end of space"); | |
6885 | 9471 assert(chunk_at_end->end() == (uintptr_t*) _cmsSpace->end(), |
0 | 9472 "Shrinking is inconsistent"); |
9473 return; | |
9474 } | |
9475 } | |
9476 // Transfer some number of overflown objects to usual marking | |
9477 // stack. Return true if some objects were transferred. | |
9478 bool MarkRefsIntoAndScanClosure::take_from_overflow_list() { | |
679
cea947c8a988
6819891: ParNew: Fix work queue overflow code to deal correctly with +UseCompressedOops
ysr
parents:
628
diff
changeset
|
9479 size_t num = MIN2((size_t)(_mark_stack->capacity() - _mark_stack->length())/4, |
0 | 9480 (size_t)ParGCDesiredObjsFromOverflowList); |
9481 | |
9482 bool res = _collector->take_from_overflow_list(num, _mark_stack); | |
9483 assert(_collector->overflow_list_is_empty() || res, | |
9484 "If list is not empty, we should have taken something"); | |
9485 assert(!res || !_mark_stack->isEmpty(), | |
9486 "If we took something, it should now be on our stack"); | |
9487 return res; | |
9488 } | |
9489 | |
9490 size_t MarkDeadObjectsClosure::do_blk(HeapWord* addr) { | |
9491 size_t res = _sp->block_size_no_stall(addr, _collector); | |
9492 if (_sp->block_is_obj(addr)) { | |
9493 if (_live_bit_map->isMarked(addr)) { | |
9494 // It can't have been dead in a previous cycle | |
9495 guarantee(!_dead_bit_map->isMarked(addr), "No resurrection!"); | |
9496 } else { | |
9497 _dead_bit_map->mark(addr); // mark the dead object | |
9498 } | |
9499 } | |
2226
c5a923563727
6912621: iCMS: Error: assert(_markBitMap.isMarked(addr + 1),"Missing Printezis bit?")
ysr
parents:
2177
diff
changeset
|
9500 // Could be 0, if the block size could not be computed without stalling. |
0 | 9501 return res; |
9502 } | |
1703
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9503 |
3356
78542e2b5e35
7036199: Adding a notification to the implementation of GarbageCollectorMXBeans
fparain
parents:
3293
diff
changeset
|
9504 TraceCMSMemoryManagerStats::TraceCMSMemoryManagerStats(CMSCollector::CollectorState phase, GCCause::Cause cause): TraceMemoryManagerStats() { |
1703
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9505 |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9506 switch (phase) { |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9507 case CMSCollector::InitialMarking: |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9508 initialize(true /* fullGC */ , |
3356
78542e2b5e35
7036199: Adding a notification to the implementation of GarbageCollectorMXBeans
fparain
parents:
3293
diff
changeset
|
9509 cause /* cause of the GC */, |
1703
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9510 true /* recordGCBeginTime */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9511 true /* recordPreGCUsage */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9512 false /* recordPeakUsage */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9513 false /* recordPostGCusage */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9514 true /* recordAccumulatedGCTime */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9515 false /* recordGCEndTime */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9516 false /* countCollection */ ); |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9517 break; |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9518 |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9519 case CMSCollector::FinalMarking: |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9520 initialize(true /* fullGC */ , |
3356
78542e2b5e35
7036199: Adding a notification to the implementation of GarbageCollectorMXBeans
fparain
parents:
3293
diff
changeset
|
9521 cause /* cause of the GC */, |
1703
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9522 false /* recordGCBeginTime */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9523 false /* recordPreGCUsage */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9524 false /* recordPeakUsage */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9525 false /* recordPostGCusage */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9526 true /* recordAccumulatedGCTime */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9527 false /* recordGCEndTime */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9528 false /* countCollection */ ); |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9529 break; |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9530 |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9531 case CMSCollector::Sweeping: |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9532 initialize(true /* fullGC */ , |
3356
78542e2b5e35
7036199: Adding a notification to the implementation of GarbageCollectorMXBeans
fparain
parents:
3293
diff
changeset
|
9533 cause /* cause of the GC */, |
1703
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9534 false /* recordGCBeginTime */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9535 false /* recordPreGCUsage */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9536 true /* recordPeakUsage */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9537 true /* recordPostGCusage */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9538 false /* recordAccumulatedGCTime */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9539 true /* recordGCEndTime */, |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9540 true /* countCollection */ ); |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9541 break; |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9542 |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9543 default: |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9544 ShouldNotReachHere(); |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9545 } |
f6f3eef8a521
6581734: CMS Old Gen's collection usage is zero after GC which is incorrect
kevinw
parents:
1579
diff
changeset
|
9546 } |