Mercurial > hg > truffle
annotate src/share/vm/memory/tenuredGeneration.cpp @ 3229:4a6bda6cfe28
Fix for usages that are phi in rematerialization
author | Gilles Duboscq <gilles.duboscq@oracle.com> |
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date | Thu, 21 Jul 2011 11:32:22 +0200 |
parents | f95d63e2154a |
children | d2a62e0f25eb |
rev | line source |
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0 | 1 /* |
1972 | 2 * Copyright (c) 2001, 2010, 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 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "gc_implementation/parNew/parGCAllocBuffer.hpp" | |
27 #include "gc_implementation/shared/collectorCounters.hpp" | |
28 #include "memory/allocation.inline.hpp" | |
29 #include "memory/blockOffsetTable.inline.hpp" | |
30 #include "memory/generation.inline.hpp" | |
31 #include "memory/generationSpec.hpp" | |
32 #include "memory/space.hpp" | |
33 #include "memory/tenuredGeneration.hpp" | |
34 #include "oops/oop.inline.hpp" | |
35 #include "runtime/java.hpp" | |
0 | 36 |
37 TenuredGeneration::TenuredGeneration(ReservedSpace rs, | |
38 size_t initial_byte_size, int level, | |
39 GenRemSet* remset) : | |
40 OneContigSpaceCardGeneration(rs, initial_byte_size, | |
41 MinHeapDeltaBytes, level, remset, NULL) | |
42 { | |
43 HeapWord* bottom = (HeapWord*) _virtual_space.low(); | |
44 HeapWord* end = (HeapWord*) _virtual_space.high(); | |
45 _the_space = new TenuredSpace(_bts, MemRegion(bottom, end)); | |
46 _the_space->reset_saved_mark(); | |
47 _shrink_factor = 0; | |
48 _capacity_at_prologue = 0; | |
49 | |
50 _gc_stats = new GCStats(); | |
51 | |
52 // initialize performance counters | |
53 | |
54 const char* gen_name = "old"; | |
55 | |
56 // Generation Counters -- generation 1, 1 subspace | |
57 _gen_counters = new GenerationCounters(gen_name, 1, 1, &_virtual_space); | |
58 | |
59 _gc_counters = new CollectorCounters("MSC", 1); | |
60 | |
61 _space_counters = new CSpaceCounters(gen_name, 0, | |
62 _virtual_space.reserved_size(), | |
63 _the_space, _gen_counters); | |
64 #ifndef SERIALGC | |
65 if (UseParNewGC && ParallelGCThreads > 0) { | |
66 typedef ParGCAllocBufferWithBOT* ParGCAllocBufferWithBOTPtr; | |
67 _alloc_buffers = NEW_C_HEAP_ARRAY(ParGCAllocBufferWithBOTPtr, | |
68 ParallelGCThreads); | |
69 if (_alloc_buffers == NULL) | |
70 vm_exit_during_initialization("Could not allocate alloc_buffers"); | |
71 for (uint i = 0; i < ParallelGCThreads; i++) { | |
72 _alloc_buffers[i] = | |
73 new ParGCAllocBufferWithBOT(OldPLABSize, _bts); | |
74 if (_alloc_buffers[i] == NULL) | |
75 vm_exit_during_initialization("Could not allocate alloc_buffers"); | |
76 } | |
77 } else { | |
78 _alloc_buffers = NULL; | |
79 } | |
80 #endif // SERIALGC | |
81 } | |
82 | |
83 | |
84 const char* TenuredGeneration::name() const { | |
85 return "tenured generation"; | |
86 } | |
87 | |
88 void TenuredGeneration::compute_new_size() { | |
89 assert(_shrink_factor <= 100, "invalid shrink factor"); | |
90 size_t current_shrink_factor = _shrink_factor; | |
91 _shrink_factor = 0; | |
92 | |
93 // We don't have floating point command-line arguments | |
94 // Note: argument processing ensures that MinHeapFreeRatio < 100. | |
95 const double minimum_free_percentage = MinHeapFreeRatio / 100.0; | |
96 const double maximum_used_percentage = 1.0 - minimum_free_percentage; | |
97 | |
98 // Compute some numbers about the state of the heap. | |
99 const size_t used_after_gc = used(); | |
100 const size_t capacity_after_gc = capacity(); | |
101 | |
102 const double min_tmp = used_after_gc / maximum_used_percentage; | |
103 size_t minimum_desired_capacity = (size_t)MIN2(min_tmp, double(max_uintx)); | |
104 // Don't shrink less than the initial generation size | |
105 minimum_desired_capacity = MAX2(minimum_desired_capacity, | |
106 spec()->init_size()); | |
107 assert(used_after_gc <= minimum_desired_capacity, "sanity check"); | |
108 | |
109 if (PrintGC && Verbose) { | |
110 const size_t free_after_gc = free(); | |
111 const double free_percentage = ((double)free_after_gc) / capacity_after_gc; | |
112 gclog_or_tty->print_cr("TenuredGeneration::compute_new_size: "); | |
113 gclog_or_tty->print_cr(" " | |
114 " minimum_free_percentage: %6.2f" | |
115 " maximum_used_percentage: %6.2f", | |
116 minimum_free_percentage, | |
117 maximum_used_percentage); | |
118 gclog_or_tty->print_cr(" " | |
119 " free_after_gc : %6.1fK" | |
120 " used_after_gc : %6.1fK" | |
121 " capacity_after_gc : %6.1fK", | |
122 free_after_gc / (double) K, | |
123 used_after_gc / (double) K, | |
124 capacity_after_gc / (double) K); | |
125 gclog_or_tty->print_cr(" " | |
126 " free_percentage: %6.2f", | |
127 free_percentage); | |
128 } | |
129 | |
130 if (capacity_after_gc < minimum_desired_capacity) { | |
131 // If we have less free space than we want then expand | |
132 size_t expand_bytes = minimum_desired_capacity - capacity_after_gc; | |
133 // Don't expand unless it's significant | |
134 if (expand_bytes >= _min_heap_delta_bytes) { | |
135 expand(expand_bytes, 0); // safe if expansion fails | |
136 } | |
137 if (PrintGC && Verbose) { | |
138 gclog_or_tty->print_cr(" expanding:" | |
139 " minimum_desired_capacity: %6.1fK" | |
140 " expand_bytes: %6.1fK" | |
141 " _min_heap_delta_bytes: %6.1fK", | |
142 minimum_desired_capacity / (double) K, | |
143 expand_bytes / (double) K, | |
144 _min_heap_delta_bytes / (double) K); | |
145 } | |
146 return; | |
147 } | |
148 | |
149 // No expansion, now see if we want to shrink | |
150 size_t shrink_bytes = 0; | |
151 // We would never want to shrink more than this | |
152 size_t max_shrink_bytes = capacity_after_gc - minimum_desired_capacity; | |
153 | |
154 if (MaxHeapFreeRatio < 100) { | |
155 const double maximum_free_percentage = MaxHeapFreeRatio / 100.0; | |
156 const double minimum_used_percentage = 1.0 - maximum_free_percentage; | |
157 const double max_tmp = used_after_gc / minimum_used_percentage; | |
158 size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx)); | |
159 maximum_desired_capacity = MAX2(maximum_desired_capacity, | |
160 spec()->init_size()); | |
161 if (PrintGC && Verbose) { | |
162 gclog_or_tty->print_cr(" " | |
163 " maximum_free_percentage: %6.2f" | |
164 " minimum_used_percentage: %6.2f", | |
165 maximum_free_percentage, | |
166 minimum_used_percentage); | |
167 gclog_or_tty->print_cr(" " | |
168 " _capacity_at_prologue: %6.1fK" | |
169 " minimum_desired_capacity: %6.1fK" | |
170 " maximum_desired_capacity: %6.1fK", | |
171 _capacity_at_prologue / (double) K, | |
172 minimum_desired_capacity / (double) K, | |
173 maximum_desired_capacity / (double) K); | |
174 } | |
175 assert(minimum_desired_capacity <= maximum_desired_capacity, | |
176 "sanity check"); | |
177 | |
178 if (capacity_after_gc > maximum_desired_capacity) { | |
179 // Capacity too large, compute shrinking size | |
180 shrink_bytes = capacity_after_gc - maximum_desired_capacity; | |
181 // We don't want shrink all the way back to initSize if people call | |
182 // System.gc(), because some programs do that between "phases" and then | |
183 // we'd just have to grow the heap up again for the next phase. So we | |
184 // damp the shrinking: 0% on the first call, 10% on the second call, 40% | |
185 // on the third call, and 100% by the fourth call. But if we recompute | |
186 // size without shrinking, it goes back to 0%. | |
187 shrink_bytes = shrink_bytes / 100 * current_shrink_factor; | |
188 assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size"); | |
189 if (current_shrink_factor == 0) { | |
190 _shrink_factor = 10; | |
191 } else { | |
192 _shrink_factor = MIN2(current_shrink_factor * 4, (size_t) 100); | |
193 } | |
194 if (PrintGC && Verbose) { | |
195 gclog_or_tty->print_cr(" " | |
196 " shrinking:" | |
197 " initSize: %.1fK" | |
198 " maximum_desired_capacity: %.1fK", | |
199 spec()->init_size() / (double) K, | |
200 maximum_desired_capacity / (double) K); | |
201 gclog_or_tty->print_cr(" " | |
202 " shrink_bytes: %.1fK" | |
203 " current_shrink_factor: %d" | |
204 " new shrink factor: %d" | |
205 " _min_heap_delta_bytes: %.1fK", | |
206 shrink_bytes / (double) K, | |
207 current_shrink_factor, | |
208 _shrink_factor, | |
209 _min_heap_delta_bytes / (double) K); | |
210 } | |
211 } | |
212 } | |
213 | |
214 if (capacity_after_gc > _capacity_at_prologue) { | |
215 // We might have expanded for promotions, in which case we might want to | |
216 // take back that expansion if there's room after GC. That keeps us from | |
217 // stretching the heap with promotions when there's plenty of room. | |
218 size_t expansion_for_promotion = capacity_after_gc - _capacity_at_prologue; | |
219 expansion_for_promotion = MIN2(expansion_for_promotion, max_shrink_bytes); | |
220 // We have two shrinking computations, take the largest | |
221 shrink_bytes = MAX2(shrink_bytes, expansion_for_promotion); | |
222 assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size"); | |
223 if (PrintGC && Verbose) { | |
224 gclog_or_tty->print_cr(" " | |
225 " aggressive shrinking:" | |
226 " _capacity_at_prologue: %.1fK" | |
227 " capacity_after_gc: %.1fK" | |
228 " expansion_for_promotion: %.1fK" | |
229 " shrink_bytes: %.1fK", | |
230 capacity_after_gc / (double) K, | |
231 _capacity_at_prologue / (double) K, | |
232 expansion_for_promotion / (double) K, | |
233 shrink_bytes / (double) K); | |
234 } | |
235 } | |
236 // Don't shrink unless it's significant | |
237 if (shrink_bytes >= _min_heap_delta_bytes) { | |
238 shrink(shrink_bytes); | |
239 } | |
240 assert(used() == used_after_gc && used_after_gc <= capacity(), | |
241 "sanity check"); | |
242 } | |
243 | |
244 void TenuredGeneration::gc_prologue(bool full) { | |
245 _capacity_at_prologue = capacity(); | |
246 _used_at_prologue = used(); | |
247 if (VerifyBeforeGC) { | |
248 verify_alloc_buffers_clean(); | |
249 } | |
250 } | |
251 | |
252 void TenuredGeneration::gc_epilogue(bool full) { | |
253 if (VerifyAfterGC) { | |
254 verify_alloc_buffers_clean(); | |
255 } | |
256 OneContigSpaceCardGeneration::gc_epilogue(full); | |
257 } | |
258 | |
259 | |
260 bool TenuredGeneration::should_collect(bool full, | |
261 size_t size, | |
262 bool is_tlab) { | |
263 // This should be one big conditional or (||), but I want to be able to tell | |
264 // why it returns what it returns (without re-evaluating the conditionals | |
265 // in case they aren't idempotent), so I'm doing it this way. | |
266 // DeMorgan says it's okay. | |
267 bool result = false; | |
268 if (!result && full) { | |
269 result = true; | |
270 if (PrintGC && Verbose) { | |
271 gclog_or_tty->print_cr("TenuredGeneration::should_collect: because" | |
272 " full"); | |
273 } | |
274 } | |
275 if (!result && should_allocate(size, is_tlab)) { | |
276 result = true; | |
277 if (PrintGC && Verbose) { | |
278 gclog_or_tty->print_cr("TenuredGeneration::should_collect: because" | |
279 " should_allocate(" SIZE_FORMAT ")", | |
280 size); | |
281 } | |
282 } | |
283 // If we don't have very much free space. | |
284 // XXX: 10000 should be a percentage of the capacity!!! | |
285 if (!result && free() < 10000) { | |
286 result = true; | |
287 if (PrintGC && Verbose) { | |
288 gclog_or_tty->print_cr("TenuredGeneration::should_collect: because" | |
289 " free(): " SIZE_FORMAT, | |
290 free()); | |
291 } | |
292 } | |
293 // If we had to expand to accomodate promotions from younger generations | |
294 if (!result && _capacity_at_prologue < capacity()) { | |
295 result = true; | |
296 if (PrintGC && Verbose) { | |
297 gclog_or_tty->print_cr("TenuredGeneration::should_collect: because" | |
298 "_capacity_at_prologue: " SIZE_FORMAT " < capacity(): " SIZE_FORMAT, | |
299 _capacity_at_prologue, capacity()); | |
300 } | |
301 } | |
302 return result; | |
303 } | |
304 | |
305 void TenuredGeneration::collect(bool full, | |
306 bool clear_all_soft_refs, | |
307 size_t size, | |
308 bool is_tlab) { | |
309 retire_alloc_buffers_before_full_gc(); | |
310 OneContigSpaceCardGeneration::collect(full, clear_all_soft_refs, | |
311 size, is_tlab); | |
312 } | |
313 | |
314 void TenuredGeneration::update_gc_stats(int current_level, | |
315 bool full) { | |
316 // If the next lower level(s) has been collected, gather any statistics | |
317 // that are of interest at this point. | |
318 if (!full && (current_level + 1) == level()) { | |
319 // Calculate size of data promoted from the younger generations | |
320 // before doing the collection. | |
321 size_t used_before_gc = used(); | |
322 | |
323 // If the younger gen collections were skipped, then the | |
324 // number of promoted bytes will be 0 and adding it to the | |
325 // average will incorrectly lessen the average. It is, however, | |
326 // also possible that no promotion was needed. | |
327 if (used_before_gc >= _used_at_prologue) { | |
328 size_t promoted_in_bytes = used_before_gc - _used_at_prologue; | |
329 gc_stats()->avg_promoted()->sample(promoted_in_bytes); | |
330 } | |
331 } | |
332 } | |
333 | |
334 void TenuredGeneration::update_counters() { | |
335 if (UsePerfData) { | |
336 _space_counters->update_all(); | |
337 _gen_counters->update_all(); | |
338 } | |
339 } | |
340 | |
341 | |
342 #ifndef SERIALGC | |
343 oop TenuredGeneration::par_promote(int thread_num, | |
344 oop old, markOop m, size_t word_sz) { | |
345 | |
346 ParGCAllocBufferWithBOT* buf = _alloc_buffers[thread_num]; | |
347 HeapWord* obj_ptr = buf->allocate(word_sz); | |
348 bool is_lab = true; | |
349 if (obj_ptr == NULL) { | |
350 #ifndef PRODUCT | |
351 if (Universe::heap()->promotion_should_fail()) { | |
352 return NULL; | |
353 } | |
354 #endif // #ifndef PRODUCT | |
355 | |
356 // Slow path: | |
357 if (word_sz * 100 < ParallelGCBufferWastePct * buf->word_sz()) { | |
358 // Is small enough; abandon this buffer and start a new one. | |
359 size_t buf_size = buf->word_sz(); | |
360 HeapWord* buf_space = | |
361 TenuredGeneration::par_allocate(buf_size, false); | |
362 if (buf_space == NULL) { | |
363 buf_space = expand_and_allocate(buf_size, false, true /* parallel*/); | |
364 } | |
365 if (buf_space != NULL) { | |
366 buf->retire(false, false); | |
367 buf->set_buf(buf_space); | |
368 obj_ptr = buf->allocate(word_sz); | |
369 assert(obj_ptr != NULL, "Buffer was definitely big enough..."); | |
370 } | |
371 }; | |
372 // Otherwise, buffer allocation failed; try allocating object | |
373 // individually. | |
374 if (obj_ptr == NULL) { | |
375 obj_ptr = TenuredGeneration::par_allocate(word_sz, false); | |
376 if (obj_ptr == NULL) { | |
377 obj_ptr = expand_and_allocate(word_sz, false, true /* parallel */); | |
378 } | |
379 } | |
380 if (obj_ptr == NULL) return NULL; | |
381 } | |
382 assert(obj_ptr != NULL, "program logic"); | |
383 Copy::aligned_disjoint_words((HeapWord*)old, obj_ptr, word_sz); | |
384 oop obj = oop(obj_ptr); | |
385 // Restore the mark word copied above. | |
386 obj->set_mark(m); | |
387 return obj; | |
388 } | |
389 | |
390 void TenuredGeneration::par_promote_alloc_undo(int thread_num, | |
391 HeapWord* obj, | |
392 size_t word_sz) { | |
393 ParGCAllocBufferWithBOT* buf = _alloc_buffers[thread_num]; | |
394 if (buf->contains(obj)) { | |
395 guarantee(buf->contains(obj + word_sz - 1), | |
396 "should contain whole object"); | |
397 buf->undo_allocation(obj, word_sz); | |
398 } else { | |
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399 CollectedHeap::fill_with_object(obj, word_sz); |
0 | 400 } |
401 } | |
402 | |
403 void TenuredGeneration::par_promote_alloc_done(int thread_num) { | |
404 ParGCAllocBufferWithBOT* buf = _alloc_buffers[thread_num]; | |
405 buf->retire(true, ParallelGCRetainPLAB); | |
406 } | |
407 | |
408 void TenuredGeneration::retire_alloc_buffers_before_full_gc() { | |
409 if (UseParNewGC) { | |
410 for (uint i = 0; i < ParallelGCThreads; i++) { | |
411 _alloc_buffers[i]->retire(true /*end_of_gc*/, false /*retain*/); | |
412 } | |
413 } | |
414 } | |
415 | |
416 // Verify that any retained parallel allocation buffers do not | |
417 // intersect with dirty cards. | |
418 void TenuredGeneration::verify_alloc_buffers_clean() { | |
419 if (UseParNewGC) { | |
420 for (uint i = 0; i < ParallelGCThreads; i++) { | |
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421 _rs->verify_aligned_region_empty(_alloc_buffers[i]->range()); |
0 | 422 } |
423 } | |
424 } | |
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425 |
0 | 426 #else // SERIALGC |
427 void TenuredGeneration::retire_alloc_buffers_before_full_gc() {} | |
428 void TenuredGeneration::verify_alloc_buffers_clean() {} | |
429 #endif // SERIALGC | |
430 | |
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431 bool TenuredGeneration::promotion_attempt_is_safe(size_t max_promotion_in_bytes) const { |
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432 size_t available = max_contiguous_available(); |
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433 size_t av_promo = (size_t)gc_stats()->avg_promoted()->padded_average(); |
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434 bool res = (available >= av_promo) || (available >= max_promotion_in_bytes); |
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435 if (PrintGC && Verbose) { |
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436 gclog_or_tty->print_cr( |
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437 "Tenured: promo attempt is%s safe: available("SIZE_FORMAT") %s av_promo("SIZE_FORMAT")," |
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438 "max_promo("SIZE_FORMAT")", |
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439 res? "":" not", available, res? ">=":"<", |
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440 av_promo, max_promotion_in_bytes); |
0 | 441 } |
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442 return res; |
0 | 443 } |