Mercurial > hg > truffle
annotate src/share/vm/runtime/sweeper.cpp @ 1538:bfe29ec02863
6950075: nmethod sweeper should operate concurrently
Reviewed-by: never, kvn
Contributed-by: eric.caspole@amd.com
| author | never |
|---|---|
| date | Mon, 17 May 2010 16:50:07 -0700 |
| parents | 5f24d0319e54 |
| children | c18cbe5936b8 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 948 | 2 * Copyright 1997-2009 Sun Microsystems, Inc. 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 * | |
| 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 # include "incls/_precompiled.incl" | |
| 26 # include "incls/_sweeper.cpp.incl" | |
| 27 | |
| 28 long NMethodSweeper::_traversals = 0; // No. of stack traversals performed | |
| 29 CodeBlob* NMethodSweeper::_current = NULL; // Current nmethod | |
| 30 int NMethodSweeper::_seen = 0 ; // No. of blobs we have currently processed in current pass of CodeCache | |
| 31 int NMethodSweeper::_invocations = 0; // No. of invocations left until we are completed with this pass | |
| 32 | |
| 33 jint NMethodSweeper::_locked_seen = 0; | |
| 34 jint NMethodSweeper::_not_entrant_seen_on_stack = 0; | |
| 35 bool NMethodSweeper::_rescan = false; | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
36 bool NMethodSweeper::_do_sweep = false; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
37 jint NMethodSweeper::_sweep_started = 0; |
| 1202 | 38 bool NMethodSweeper::_was_full = false; |
| 39 jint NMethodSweeper::_advise_to_sweep = 0; | |
| 40 jlong NMethodSweeper::_last_was_full = 0; | |
| 41 uint NMethodSweeper::_highest_marked = 0; | |
| 42 long NMethodSweeper::_was_full_traversal = 0; | |
| 0 | 43 |
| 989 | 44 class MarkActivationClosure: public CodeBlobClosure { |
| 45 public: | |
| 46 virtual void do_code_blob(CodeBlob* cb) { | |
| 47 // If we see an activation belonging to a non_entrant nmethod, we mark it. | |
| 48 if (cb->is_nmethod() && ((nmethod*)cb)->is_not_entrant()) { | |
| 49 ((nmethod*)cb)->mark_as_seen_on_stack(); | |
| 50 } | |
| 51 } | |
| 52 }; | |
| 53 static MarkActivationClosure mark_activation_closure; | |
| 54 | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
55 void NMethodSweeper::scan_stacks() { |
| 0 | 56 assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint"); |
| 57 if (!MethodFlushing) return; | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
58 _do_sweep = true; |
| 0 | 59 |
| 60 // No need to synchronize access, since this is always executed at a | |
| 61 // safepoint. If we aren't in the middle of scan and a rescan | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
62 // hasn't been requested then just return. If UseCodeCacheFlushing is on and |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
63 // code cache flushing is in progress, don't skip sweeping to help make progress |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
64 // clearing space in the code cache. |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
65 if ((_current == NULL && !_rescan) && !(UseCodeCacheFlushing && !CompileBroker::should_compile_new_jobs())) { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
66 _do_sweep = false; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
67 return; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
68 } |
| 0 | 69 |
| 70 // Make sure CompiledIC_lock in unlocked, since we might update some | |
| 71 // inline caches. If it is, we just bail-out and try later. | |
| 72 if (CompiledIC_lock->is_locked() || Patching_lock->is_locked()) return; | |
| 73 | |
| 74 // Check for restart | |
| 75 assert(CodeCache::find_blob_unsafe(_current) == _current, "Sweeper nmethod cached state invalid"); | |
| 76 if (_current == NULL) { | |
| 77 _seen = 0; | |
| 78 _invocations = NmethodSweepFraction; | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
79 _current = CodeCache::first_nmethod(); |
| 0 | 80 _traversals += 1; |
| 81 if (PrintMethodFlushing) { | |
| 82 tty->print_cr("### Sweep: stack traversal %d", _traversals); | |
| 83 } | |
| 989 | 84 Threads::nmethods_do(&mark_activation_closure); |
| 0 | 85 |
| 86 // reset the flags since we started a scan from the beginning. | |
| 87 _rescan = false; | |
| 88 _locked_seen = 0; | |
| 89 _not_entrant_seen_on_stack = 0; | |
| 90 } | |
| 91 | |
| 1202 | 92 if (UseCodeCacheFlushing) { |
| 93 if (!CodeCache::needs_flushing()) { | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
94 // scan_stacks() runs during a safepoint, no race with setters |
| 1202 | 95 _advise_to_sweep = 0; |
| 96 } | |
| 97 | |
| 98 if (was_full()) { | |
| 99 // There was some progress so attempt to restart the compiler | |
| 100 jlong now = os::javaTimeMillis(); | |
| 101 jlong max_interval = (jlong)MinCodeCacheFlushingInterval * (jlong)1000; | |
| 102 jlong curr_interval = now - _last_was_full; | |
| 103 if ((!CodeCache::needs_flushing()) && (curr_interval > max_interval)) { | |
| 104 CompileBroker::set_should_compile_new_jobs(CompileBroker::run_compilation); | |
| 105 set_was_full(false); | |
| 106 | |
| 107 // Update the _last_was_full time so we can tell how fast the | |
| 108 // code cache is filling up | |
| 109 _last_was_full = os::javaTimeMillis(); | |
| 110 | |
| 111 if (PrintMethodFlushing) { | |
| 112 tty->print_cr("### sweeper: Live blobs:" UINT32_FORMAT "/Free code cache:" SIZE_FORMAT " bytes, restarting compiler", | |
| 113 CodeCache::nof_blobs(), CodeCache::unallocated_capacity()); | |
| 114 } | |
| 115 if (LogCompilation && (xtty != NULL)) { | |
| 116 ttyLocker ttyl; | |
| 117 xtty->begin_elem("restart_compiler live_blobs='" UINT32_FORMAT "' free_code_cache='" SIZE_FORMAT "'", | |
| 118 CodeCache::nof_blobs(), CodeCache::unallocated_capacity()); | |
| 119 xtty->stamp(); | |
| 120 xtty->end_elem(); | |
| 121 } | |
| 122 } | |
| 123 } | |
| 124 } | |
| 0 | 125 } |
| 126 | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
127 void NMethodSweeper::possibly_sweep() { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
128 if ((!MethodFlushing) || (!_do_sweep)) return; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
129 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
130 if (_invocations > 0) { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
131 // Only one thread at a time will sweep |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
132 jint old = Atomic::cmpxchg( 1, &_sweep_started, 0 ); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
133 if (old != 0) { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
134 return; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
135 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
136 sweep_code_cache(); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
137 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
138 _sweep_started = 0; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
139 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
140 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
141 void NMethodSweeper::sweep_code_cache() { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
142 #ifdef ASSERT |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
143 jlong sweep_start; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
144 if(PrintMethodFlushing) { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
145 sweep_start = os::javaTimeMillis(); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
146 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
147 #endif |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
148 if (PrintMethodFlushing && Verbose) { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
149 tty->print_cr("### Sweep at %d out of %d. Invocations left: %d", _seen, CodeCache::nof_blobs(), _invocations); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
150 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
151 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
152 // We want to visit all nmethods after NmethodSweepFraction invocations. |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
153 // If invocation is 1 we do the rest |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
154 int todo = CodeCache::nof_blobs(); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
155 if (_invocations > 1) { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
156 todo = (CodeCache::nof_blobs() - _seen) / _invocations; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
157 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
158 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
159 // Compilers may check to sweep more often than stack scans happen, |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
160 // don't keep trying once it is all scanned |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
161 _invocations--; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
162 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
163 assert(!SafepointSynchronize::is_at_safepoint(), "should not be in safepoint when we get here"); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
164 assert(!CodeCache_lock->owned_by_self(), "just checking"); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
165 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
166 { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
167 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
168 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
169 for(int i = 0; i < todo && _current != NULL; i++) { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
170 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
171 // Since we will give up the CodeCache_lock, always skip ahead to an nmethod. |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
172 // Other blobs can be deleted by other threads |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
173 // Read next before we potentially delete current |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
174 CodeBlob* next = CodeCache::next_nmethod(_current); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
175 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
176 // Now ready to process nmethod and give up CodeCache_lock |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
177 { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
178 MutexUnlockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
179 process_nmethod((nmethod *)_current); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
180 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
181 _seen++; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
182 _current = next; |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
183 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
184 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
185 // Skip forward to the next nmethod (if any). Code blobs other than nmethods |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
186 // can be freed async to us and make _current invalid while we sleep. |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
187 _current = CodeCache::next_nmethod(_current); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
188 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
189 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
190 if (_current == NULL && !_rescan && (_locked_seen || _not_entrant_seen_on_stack)) { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
191 // we've completed a scan without making progress but there were |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
192 // nmethods we were unable to process either because they were |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
193 // locked or were still on stack. We don't have to aggresively |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
194 // clean them up so just stop scanning. We could scan once more |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
195 // but that complicates the control logic and it's unlikely to |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
196 // matter much. |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
197 if (PrintMethodFlushing) { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
198 tty->print_cr("### Couldn't make progress on some nmethods so stopping sweep"); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
199 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
200 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
201 |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
202 #ifdef ASSERT |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
203 if(PrintMethodFlushing) { |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
204 jlong sweep_end = os::javaTimeMillis(); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
205 tty->print_cr("### sweeper: sweep time(%d): " INT64_FORMAT, _invocations, sweep_end - sweep_start); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
206 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
207 #endif |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
208 } |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
209 |
| 0 | 210 |
| 211 void NMethodSweeper::process_nmethod(nmethod *nm) { | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
212 assert(!CodeCache_lock->owned_by_self(), "just checking"); |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
213 |
| 0 | 214 // Skip methods that are currently referenced by the VM |
| 215 if (nm->is_locked_by_vm()) { | |
| 216 // But still remember to clean-up inline caches for alive nmethods | |
| 217 if (nm->is_alive()) { | |
| 218 // Clean-up all inline caches that points to zombie/non-reentrant methods | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
219 MutexLocker cl(CompiledIC_lock); |
| 0 | 220 nm->cleanup_inline_caches(); |
| 221 } else { | |
| 222 _locked_seen++; | |
| 223 } | |
| 224 return; | |
| 225 } | |
| 226 | |
| 227 if (nm->is_zombie()) { | |
| 228 // If it is first time, we see nmethod then we mark it. Otherwise, | |
| 229 // we reclame it. When we have seen a zombie method twice, we know that | |
| 230 // there are no inline caches that referes to it. | |
| 231 if (nm->is_marked_for_reclamation()) { | |
| 232 assert(!nm->is_locked_by_vm(), "must not flush locked nmethods"); | |
| 941 | 233 if (PrintMethodFlushing && Verbose) { |
| 1202 | 234 tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (marked for reclamation) being flushed", nm->compile_id(), nm); |
| 941 | 235 } |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
236 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); |
| 0 | 237 nm->flush(); |
| 238 } else { | |
| 941 | 239 if (PrintMethodFlushing && Verbose) { |
| 1202 | 240 tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (zombie) being marked for reclamation", nm->compile_id(), nm); |
| 941 | 241 } |
| 0 | 242 nm->mark_for_reclamation(); |
| 243 _rescan = true; | |
| 244 } | |
| 245 } else if (nm->is_not_entrant()) { | |
| 246 // If there is no current activations of this method on the | |
| 247 // stack we can safely convert it to a zombie method | |
| 248 if (nm->can_not_entrant_be_converted()) { | |
| 941 | 249 if (PrintMethodFlushing && Verbose) { |
| 1202 | 250 tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (not entrant) being made zombie", nm->compile_id(), nm); |
| 941 | 251 } |
| 0 | 252 nm->make_zombie(); |
| 253 _rescan = true; | |
| 254 } else { | |
| 255 // Still alive, clean up its inline caches | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
256 MutexLocker cl(CompiledIC_lock); |
| 0 | 257 nm->cleanup_inline_caches(); |
| 258 // we coudn't transition this nmethod so don't immediately | |
| 259 // request a rescan. If this method stays on the stack for a | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
260 // long time we don't want to keep rescanning the code cache. |
| 0 | 261 _not_entrant_seen_on_stack++; |
| 262 } | |
| 263 } else if (nm->is_unloaded()) { | |
| 264 // Unloaded code, just make it a zombie | |
| 941 | 265 if (PrintMethodFlushing && Verbose) |
| 1202 | 266 tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (unloaded) being made zombie", nm->compile_id(), nm); |
| 941 | 267 if (nm->is_osr_method()) { |
| 0 | 268 // No inline caches will ever point to osr methods, so we can just remove it |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
269 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag); |
| 0 | 270 nm->flush(); |
| 271 } else { | |
| 272 nm->make_zombie(); | |
| 273 _rescan = true; | |
| 274 } | |
| 275 } else { | |
| 276 assert(nm->is_alive(), "should be alive"); | |
| 1202 | 277 |
| 278 if (UseCodeCacheFlushing) { | |
| 279 if ((nm->method()->code() != nm) && !(nm->is_locked_by_vm()) && !(nm->is_osr_method()) && | |
| 280 (_traversals > _was_full_traversal+2) && (((uint)nm->compile_id()) < _highest_marked) && | |
| 281 CodeCache::needs_flushing()) { | |
| 282 // This method has not been called since the forced cleanup happened | |
| 283 nm->make_not_entrant(); | |
| 284 } | |
| 285 } | |
| 286 | |
| 0 | 287 // Clean-up all inline caches that points to zombie/non-reentrant methods |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
288 MutexLocker cl(CompiledIC_lock); |
| 0 | 289 nm->cleanup_inline_caches(); |
| 290 } | |
| 291 } | |
| 1202 | 292 |
| 293 // Code cache unloading: when compilers notice the code cache is getting full, | |
| 294 // they will call a vm op that comes here. This code attempts to speculatively | |
| 295 // unload the oldest half of the nmethods (based on the compile job id) by | |
| 296 // saving the old code in a list in the CodeCache. Then | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
297 // execution resumes. If a method so marked is not called by the second sweeper |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
298 // stack traversal after the current one, the nmethod will be marked non-entrant and |
| 1202 | 299 // got rid of by normal sweeping. If the method is called, the methodOop's |
| 300 // _code field is restored and the methodOop/nmethod | |
| 301 // go back to their normal state. | |
| 302 void NMethodSweeper::handle_full_code_cache(bool is_full) { | |
| 303 // Only the first one to notice can advise us to start early cleaning | |
| 304 if (!is_full){ | |
| 305 jint old = Atomic::cmpxchg( 1, &_advise_to_sweep, 0 ); | |
| 306 if (old != 0) { | |
| 307 return; | |
| 308 } | |
| 309 } | |
| 310 | |
| 311 if (is_full) { | |
| 312 // Since code cache is full, immediately stop new compiles | |
| 313 bool did_set = CompileBroker::set_should_compile_new_jobs(CompileBroker::stop_compilation); | |
| 314 if (!did_set) { | |
| 315 // only the first to notice can start the cleaning, | |
| 316 // others will go back and block | |
| 317 return; | |
| 318 } | |
| 319 set_was_full(true); | |
| 320 | |
| 321 // If we run out within MinCodeCacheFlushingInterval of the last unload time, give up | |
| 322 jlong now = os::javaTimeMillis(); | |
| 323 jlong max_interval = (jlong)MinCodeCacheFlushingInterval * (jlong)1000; | |
| 324 jlong curr_interval = now - _last_was_full; | |
| 325 if (curr_interval < max_interval) { | |
| 326 _rescan = true; | |
| 327 if (PrintMethodFlushing) { | |
| 328 tty->print_cr("### handle full too often, turning off compiler"); | |
| 329 } | |
| 330 if (LogCompilation && (xtty != NULL)) { | |
| 331 ttyLocker ttyl; | |
| 332 xtty->begin_elem("disable_compiler flushing_interval='" UINT64_FORMAT "' live_blobs='" UINT32_FORMAT "' free_code_cache='" SIZE_FORMAT "'", | |
| 333 curr_interval/1000, CodeCache::nof_blobs(), CodeCache::unallocated_capacity()); | |
| 334 xtty->stamp(); | |
| 335 xtty->end_elem(); | |
| 336 } | |
| 337 return; | |
| 338 } | |
| 339 } | |
| 340 | |
| 341 VM_HandleFullCodeCache op(is_full); | |
| 342 VMThread::execute(&op); | |
| 343 | |
| 344 // rescan again as soon as possible | |
| 345 _rescan = true; | |
| 346 } | |
| 347 | |
| 348 void NMethodSweeper::speculative_disconnect_nmethods(bool is_full) { | |
| 349 // If there was a race in detecting full code cache, only run | |
| 350 // one vm op for it or keep the compiler shut off | |
| 351 | |
| 352 debug_only(jlong start = os::javaTimeMillis();) | |
| 353 | |
| 354 if ((!was_full()) && (is_full)) { | |
| 355 if (!CodeCache::needs_flushing()) { | |
| 356 if (PrintMethodFlushing) { | |
| 357 tty->print_cr("### sweeper: Live blobs:" UINT32_FORMAT "/Free code cache:" SIZE_FORMAT " bytes, restarting compiler", | |
| 358 CodeCache::nof_blobs(), CodeCache::unallocated_capacity()); | |
| 359 } | |
| 360 if (LogCompilation && (xtty != NULL)) { | |
| 361 ttyLocker ttyl; | |
| 362 xtty->begin_elem("restart_compiler live_blobs='" UINT32_FORMAT "' free_code_cache='" SIZE_FORMAT "'", | |
| 363 CodeCache::nof_blobs(), CodeCache::unallocated_capacity()); | |
| 364 xtty->stamp(); | |
| 365 xtty->end_elem(); | |
| 366 } | |
| 367 CompileBroker::set_should_compile_new_jobs(CompileBroker::run_compilation); | |
| 368 return; | |
| 369 } | |
| 370 } | |
| 371 | |
| 372 // Traverse the code cache trying to dump the oldest nmethods | |
| 373 uint curr_max_comp_id = CompileBroker::get_compilation_id(); | |
| 374 uint flush_target = ((curr_max_comp_id - _highest_marked) >> 1) + _highest_marked; | |
| 375 if (PrintMethodFlushing && Verbose) { | |
| 376 tty->print_cr("### Cleaning code cache: Live blobs:" UINT32_FORMAT "/Free code cache:" SIZE_FORMAT " bytes", | |
| 377 CodeCache::nof_blobs(), CodeCache::unallocated_capacity()); | |
| 378 } | |
| 379 if (LogCompilation && (xtty != NULL)) { | |
| 380 ttyLocker ttyl; | |
| 381 xtty->begin_elem("start_cleaning_code_cache live_blobs='" UINT32_FORMAT "' free_code_cache='" SIZE_FORMAT "'", | |
| 382 CodeCache::nof_blobs(), CodeCache::unallocated_capacity()); | |
| 383 xtty->stamp(); | |
| 384 xtty->end_elem(); | |
| 385 } | |
| 386 | |
| 387 nmethod* nm = CodeCache::alive_nmethod(CodeCache::first()); | |
| 388 jint disconnected = 0; | |
| 389 jint made_not_entrant = 0; | |
| 390 while ((nm != NULL)){ | |
| 391 uint curr_comp_id = nm->compile_id(); | |
| 392 | |
| 393 // OSR methods cannot be flushed like this. Also, don't flush native methods | |
| 394 // since they are part of the JDK in most cases | |
| 395 if (nm->is_in_use() && (!nm->is_osr_method()) && (!nm->is_locked_by_vm()) && | |
| 396 (!nm->is_native_method()) && ((curr_comp_id < flush_target))) { | |
| 397 | |
| 398 if ((nm->method()->code() == nm)) { | |
| 399 // This method has not been previously considered for | |
| 400 // unloading or it was restored already | |
| 401 CodeCache::speculatively_disconnect(nm); | |
| 402 disconnected++; | |
| 403 } else if (nm->is_speculatively_disconnected()) { | |
| 404 // This method was previously considered for preemptive unloading and was not called since then | |
| 405 nm->method()->invocation_counter()->decay(); | |
| 406 nm->method()->backedge_counter()->decay(); | |
| 407 nm->make_not_entrant(); | |
| 408 made_not_entrant++; | |
| 409 } | |
| 410 | |
| 411 if (curr_comp_id > _highest_marked) { | |
| 412 _highest_marked = curr_comp_id; | |
| 413 } | |
| 414 } | |
| 415 nm = CodeCache::alive_nmethod(CodeCache::next(nm)); | |
| 416 } | |
| 417 | |
| 418 if (LogCompilation && (xtty != NULL)) { | |
| 419 ttyLocker ttyl; | |
| 420 xtty->begin_elem("stop_cleaning_code_cache disconnected='" UINT32_FORMAT "' made_not_entrant='" UINT32_FORMAT "' live_blobs='" UINT32_FORMAT "' free_code_cache='" SIZE_FORMAT "'", | |
| 421 disconnected, made_not_entrant, CodeCache::nof_blobs(), CodeCache::unallocated_capacity()); | |
| 422 xtty->stamp(); | |
| 423 xtty->end_elem(); | |
| 424 } | |
| 425 | |
|
1538
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
426 // Shut off compiler. Sweeper will start over with a new stack scan and |
|
bfe29ec02863
6950075: nmethod sweeper should operate concurrently
never
parents:
1202
diff
changeset
|
427 // traversal cycle and turn it back on if it clears enough space. |
| 1202 | 428 if (was_full()) { |
| 429 _last_was_full = os::javaTimeMillis(); | |
| 430 CompileBroker::set_should_compile_new_jobs(CompileBroker::stop_compilation); | |
| 431 } | |
| 432 | |
| 433 // After two more traversals the sweeper will get rid of unrestored nmethods | |
| 434 _was_full_traversal = _traversals; | |
| 435 #ifdef ASSERT | |
| 436 jlong end = os::javaTimeMillis(); | |
| 437 if(PrintMethodFlushing && Verbose) { | |
| 438 tty->print_cr("### sweeper: unload time: " INT64_FORMAT, end-start); | |
| 439 } | |
| 440 #endif | |
| 441 } |