Mercurial > hg > truffle
annotate src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp @ 113:ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold
| author | coleenp |
|---|---|
| date | Sun, 13 Apr 2008 17:43:42 -0400 |
| parents | a61af66fc99e |
| children | d1605aabd0a1 12eea04c8b06 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 * Copyright 2002-2007 Sun Microsystems, Inc. All Rights Reserved. | |
| 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 | |
| 26 # include "incls/_precompiled.incl" | |
| 27 # include "incls/_psScavenge.cpp.incl" | |
| 28 | |
| 29 HeapWord* PSScavenge::_to_space_top_before_gc = NULL; | |
| 30 int PSScavenge::_consecutive_skipped_scavenges = 0; | |
| 31 ReferenceProcessor* PSScavenge::_ref_processor = NULL; | |
| 32 CardTableExtension* PSScavenge::_card_table = NULL; | |
| 33 bool PSScavenge::_survivor_overflow = false; | |
| 34 int PSScavenge::_tenuring_threshold = 0; | |
| 35 HeapWord* PSScavenge::_young_generation_boundary = NULL; | |
| 36 elapsedTimer PSScavenge::_accumulated_time; | |
| 37 GrowableArray<markOop>* PSScavenge::_preserved_mark_stack = NULL; | |
| 38 GrowableArray<oop>* PSScavenge::_preserved_oop_stack = NULL; | |
| 39 CollectorCounters* PSScavenge::_counters = NULL; | |
| 40 | |
| 41 // Define before use | |
| 42 class PSIsAliveClosure: public BoolObjectClosure { | |
| 43 public: | |
| 44 void do_object(oop p) { | |
| 45 assert(false, "Do not call."); | |
| 46 } | |
| 47 bool do_object_b(oop p) { | |
| 48 return (!PSScavenge::is_obj_in_young((HeapWord*) p)) || p->is_forwarded(); | |
| 49 } | |
| 50 }; | |
| 51 | |
| 52 PSIsAliveClosure PSScavenge::_is_alive_closure; | |
| 53 | |
| 54 class PSKeepAliveClosure: public OopClosure { | |
| 55 protected: | |
| 56 MutableSpace* _to_space; | |
| 57 PSPromotionManager* _promotion_manager; | |
| 58 | |
| 59 public: | |
| 60 PSKeepAliveClosure(PSPromotionManager* pm) : _promotion_manager(pm) { | |
| 61 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 62 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 63 _to_space = heap->young_gen()->to_space(); | |
| 64 | |
| 65 assert(_promotion_manager != NULL, "Sanity"); | |
| 66 } | |
| 67 | |
|
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6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
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68 template <class T> void do_oop_work(T* p) { |
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69 assert (!oopDesc::is_null(*p), "expected non-null ref"); |
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70 assert ((oopDesc::load_decode_heap_oop_not_null(p))->is_oop(), |
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71 "expected an oop while scanning weak refs"); |
| 0 | 72 |
| 73 // Weak refs may be visited more than once. | |
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74 if (PSScavenge::should_scavenge(p, _to_space)) { |
| 0 | 75 PSScavenge::copy_and_push_safe_barrier(_promotion_manager, p); |
| 76 } | |
| 77 } | |
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78 virtual void do_oop(oop* p) { PSKeepAliveClosure::do_oop_work(p); } |
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79 virtual void do_oop(narrowOop* p) { PSKeepAliveClosure::do_oop_work(p); } |
| 0 | 80 }; |
| 81 | |
| 82 class PSEvacuateFollowersClosure: public VoidClosure { | |
| 83 private: | |
| 84 PSPromotionManager* _promotion_manager; | |
| 85 public: | |
| 86 PSEvacuateFollowersClosure(PSPromotionManager* pm) : _promotion_manager(pm) {} | |
| 87 | |
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88 virtual void do_void() { |
| 0 | 89 assert(_promotion_manager != NULL, "Sanity"); |
| 90 _promotion_manager->drain_stacks(true); | |
| 91 guarantee(_promotion_manager->stacks_empty(), | |
| 92 "stacks should be empty at this point"); | |
| 93 } | |
| 94 }; | |
| 95 | |
| 96 class PSPromotionFailedClosure : public ObjectClosure { | |
| 97 virtual void do_object(oop obj) { | |
| 98 if (obj->is_forwarded()) { | |
| 99 obj->init_mark(); | |
| 100 } | |
| 101 } | |
| 102 }; | |
| 103 | |
| 104 class PSRefProcTaskProxy: public GCTask { | |
| 105 typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask; | |
| 106 ProcessTask & _rp_task; | |
| 107 uint _work_id; | |
| 108 public: | |
| 109 PSRefProcTaskProxy(ProcessTask & rp_task, uint work_id) | |
| 110 : _rp_task(rp_task), | |
| 111 _work_id(work_id) | |
| 112 { } | |
| 113 | |
| 114 private: | |
| 115 virtual char* name() { return (char *)"Process referents by policy in parallel"; } | |
| 116 virtual void do_it(GCTaskManager* manager, uint which); | |
| 117 }; | |
| 118 | |
| 119 void PSRefProcTaskProxy::do_it(GCTaskManager* manager, uint which) | |
| 120 { | |
| 121 PSPromotionManager* promotion_manager = | |
| 122 PSPromotionManager::gc_thread_promotion_manager(which); | |
| 123 assert(promotion_manager != NULL, "sanity check"); | |
| 124 PSKeepAliveClosure keep_alive(promotion_manager); | |
| 125 PSEvacuateFollowersClosure evac_followers(promotion_manager); | |
| 126 PSIsAliveClosure is_alive; | |
| 127 _rp_task.work(_work_id, is_alive, keep_alive, evac_followers); | |
| 128 } | |
| 129 | |
| 130 class PSRefEnqueueTaskProxy: public GCTask { | |
| 131 typedef AbstractRefProcTaskExecutor::EnqueueTask EnqueueTask; | |
| 132 EnqueueTask& _enq_task; | |
| 133 uint _work_id; | |
| 134 | |
| 135 public: | |
| 136 PSRefEnqueueTaskProxy(EnqueueTask& enq_task, uint work_id) | |
| 137 : _enq_task(enq_task), | |
| 138 _work_id(work_id) | |
| 139 { } | |
| 140 | |
| 141 virtual char* name() { return (char *)"Enqueue reference objects in parallel"; } | |
| 142 virtual void do_it(GCTaskManager* manager, uint which) | |
| 143 { | |
| 144 _enq_task.work(_work_id); | |
| 145 } | |
| 146 }; | |
| 147 | |
| 148 class PSRefProcTaskExecutor: public AbstractRefProcTaskExecutor { | |
| 149 virtual void execute(ProcessTask& task); | |
| 150 virtual void execute(EnqueueTask& task); | |
| 151 }; | |
| 152 | |
| 153 void PSRefProcTaskExecutor::execute(ProcessTask& task) | |
| 154 { | |
| 155 GCTaskQueue* q = GCTaskQueue::create(); | |
| 156 for(uint i=0; i<ParallelGCThreads; i++) { | |
| 157 q->enqueue(new PSRefProcTaskProxy(task, i)); | |
| 158 } | |
| 159 ParallelTaskTerminator terminator( | |
| 160 ParallelScavengeHeap::gc_task_manager()->workers(), | |
| 161 UseDepthFirstScavengeOrder ? | |
| 162 (TaskQueueSetSuper*) PSPromotionManager::stack_array_depth() | |
| 163 : (TaskQueueSetSuper*) PSPromotionManager::stack_array_breadth()); | |
| 164 if (task.marks_oops_alive() && ParallelGCThreads > 1) { | |
| 165 for (uint j=0; j<ParallelGCThreads; j++) { | |
| 166 q->enqueue(new StealTask(&terminator)); | |
| 167 } | |
| 168 } | |
| 169 ParallelScavengeHeap::gc_task_manager()->execute_and_wait(q); | |
| 170 } | |
| 171 | |
| 172 | |
| 173 void PSRefProcTaskExecutor::execute(EnqueueTask& task) | |
| 174 { | |
| 175 GCTaskQueue* q = GCTaskQueue::create(); | |
| 176 for(uint i=0; i<ParallelGCThreads; i++) { | |
| 177 q->enqueue(new PSRefEnqueueTaskProxy(task, i)); | |
| 178 } | |
| 179 ParallelScavengeHeap::gc_task_manager()->execute_and_wait(q); | |
| 180 } | |
| 181 | |
| 182 // This method contains all heap specific policy for invoking scavenge. | |
| 183 // PSScavenge::invoke_no_policy() will do nothing but attempt to | |
| 184 // scavenge. It will not clean up after failed promotions, bail out if | |
| 185 // we've exceeded policy time limits, or any other special behavior. | |
| 186 // All such policy should be placed here. | |
| 187 // | |
| 188 // Note that this method should only be called from the vm_thread while | |
| 189 // at a safepoint! | |
| 190 void PSScavenge::invoke() | |
| 191 { | |
| 192 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); | |
| 193 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); | |
| 194 assert(!Universe::heap()->is_gc_active(), "not reentrant"); | |
| 195 | |
| 196 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 197 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 198 | |
| 199 PSAdaptiveSizePolicy* policy = heap->size_policy(); | |
| 200 | |
| 201 // Before each allocation/collection attempt, find out from the | |
| 202 // policy object if GCs are, on the whole, taking too long. If so, | |
| 203 // bail out without attempting a collection. | |
| 204 if (!policy->gc_time_limit_exceeded()) { | |
| 205 IsGCActiveMark mark; | |
| 206 | |
| 207 bool scavenge_was_done = PSScavenge::invoke_no_policy(); | |
| 208 | |
| 209 PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); | |
| 210 if (UsePerfData) | |
| 211 counters->update_full_follows_scavenge(0); | |
| 212 if (!scavenge_was_done || | |
| 213 policy->should_full_GC(heap->old_gen()->free_in_bytes())) { | |
| 214 if (UsePerfData) | |
| 215 counters->update_full_follows_scavenge(full_follows_scavenge); | |
| 216 | |
| 217 GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy); | |
| 218 if (UseParallelOldGC) { | |
| 219 PSParallelCompact::invoke_no_policy(false); | |
| 220 } else { | |
| 221 PSMarkSweep::invoke_no_policy(false); | |
| 222 } | |
| 223 } | |
| 224 } | |
| 225 } | |
| 226 | |
| 227 // This method contains no policy. You should probably | |
| 228 // be calling invoke() instead. | |
| 229 bool PSScavenge::invoke_no_policy() { | |
| 230 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); | |
| 231 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); | |
| 232 | |
| 233 TimeStamp scavenge_entry; | |
| 234 TimeStamp scavenge_midpoint; | |
| 235 TimeStamp scavenge_exit; | |
| 236 | |
| 237 scavenge_entry.update(); | |
| 238 | |
| 239 if (GC_locker::check_active_before_gc()) { | |
| 240 return false; | |
| 241 } | |
| 242 | |
| 243 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 244 GCCause::Cause gc_cause = heap->gc_cause(); | |
| 245 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 246 | |
| 247 // Check for potential problems. | |
| 248 if (!should_attempt_scavenge()) { | |
| 249 return false; | |
| 250 } | |
| 251 | |
| 252 bool promotion_failure_occurred = false; | |
| 253 | |
| 254 PSYoungGen* young_gen = heap->young_gen(); | |
| 255 PSOldGen* old_gen = heap->old_gen(); | |
| 256 PSPermGen* perm_gen = heap->perm_gen(); | |
| 257 PSAdaptiveSizePolicy* size_policy = heap->size_policy(); | |
| 258 heap->increment_total_collections(); | |
| 259 | |
| 260 AdaptiveSizePolicyOutput(size_policy, heap->total_collections()); | |
| 261 | |
| 262 if ((gc_cause != GCCause::_java_lang_system_gc) || | |
| 263 UseAdaptiveSizePolicyWithSystemGC) { | |
| 264 // Gather the feedback data for eden occupancy. | |
| 265 young_gen->eden_space()->accumulate_statistics(); | |
| 266 } | |
| 267 | |
| 268 if (PrintHeapAtGC) { | |
| 269 Universe::print_heap_before_gc(); | |
| 270 } | |
| 271 | |
| 272 assert(!NeverTenure || _tenuring_threshold == markOopDesc::max_age + 1, "Sanity"); | |
| 273 assert(!AlwaysTenure || _tenuring_threshold == 0, "Sanity"); | |
| 274 | |
| 275 size_t prev_used = heap->used(); | |
| 276 assert(promotion_failed() == false, "Sanity"); | |
| 277 | |
| 278 // Fill in TLABs | |
| 279 heap->accumulate_statistics_all_tlabs(); | |
| 280 heap->ensure_parsability(true); // retire TLABs | |
| 281 | |
| 282 if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) { | |
| 283 HandleMark hm; // Discard invalid handles created during verification | |
| 284 gclog_or_tty->print(" VerifyBeforeGC:"); | |
| 285 Universe::verify(true); | |
| 286 } | |
| 287 | |
| 288 { | |
| 289 ResourceMark rm; | |
| 290 HandleMark hm; | |
| 291 | |
| 292 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); | |
| 293 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); | |
| 294 TraceTime t1("GC", PrintGC, !PrintGCDetails, gclog_or_tty); | |
| 295 TraceCollectorStats tcs(counters()); | |
| 296 TraceMemoryManagerStats tms(false /* not full GC */); | |
| 297 | |
| 298 if (TraceGen0Time) accumulated_time()->start(); | |
| 299 | |
| 300 // Let the size policy know we're starting | |
| 301 size_policy->minor_collection_begin(); | |
| 302 | |
| 303 // Verify the object start arrays. | |
| 304 if (VerifyObjectStartArray && | |
| 305 VerifyBeforeGC) { | |
| 306 old_gen->verify_object_start_array(); | |
| 307 perm_gen->verify_object_start_array(); | |
| 308 } | |
| 309 | |
| 310 // Verify no unmarked old->young roots | |
| 311 if (VerifyRememberedSets) { | |
| 312 CardTableExtension::verify_all_young_refs_imprecise(); | |
| 313 } | |
| 314 | |
| 315 if (!ScavengeWithObjectsInToSpace) { | |
| 316 assert(young_gen->to_space()->is_empty(), | |
| 317 "Attempt to scavenge with live objects in to_space"); | |
| 318 young_gen->to_space()->clear(); | |
| 319 } else if (ZapUnusedHeapArea) { | |
| 320 young_gen->to_space()->mangle_unused_area(); | |
| 321 } | |
| 322 save_to_space_top_before_gc(); | |
| 323 | |
| 324 NOT_PRODUCT(reference_processor()->verify_no_references_recorded()); | |
| 325 COMPILER2_PRESENT(DerivedPointerTable::clear()); | |
| 326 | |
| 327 reference_processor()->enable_discovery(); | |
| 328 | |
| 329 // We track how much was promoted to the next generation for | |
| 330 // the AdaptiveSizePolicy. | |
| 331 size_t old_gen_used_before = old_gen->used_in_bytes(); | |
| 332 | |
| 333 // For PrintGCDetails | |
| 334 size_t young_gen_used_before = young_gen->used_in_bytes(); | |
| 335 | |
| 336 // Reset our survivor overflow. | |
| 337 set_survivor_overflow(false); | |
| 338 | |
| 339 // We need to save the old/perm top values before | |
| 340 // creating the promotion_manager. We pass the top | |
| 341 // values to the card_table, to prevent it from | |
| 342 // straying into the promotion labs. | |
| 343 HeapWord* old_top = old_gen->object_space()->top(); | |
| 344 HeapWord* perm_top = perm_gen->object_space()->top(); | |
| 345 | |
| 346 // Release all previously held resources | |
| 347 gc_task_manager()->release_all_resources(); | |
| 348 | |
| 349 PSPromotionManager::pre_scavenge(); | |
| 350 | |
| 351 // We'll use the promotion manager again later. | |
| 352 PSPromotionManager* promotion_manager = PSPromotionManager::vm_thread_promotion_manager(); | |
| 353 { | |
| 354 // TraceTime("Roots"); | |
| 355 | |
| 356 GCTaskQueue* q = GCTaskQueue::create(); | |
| 357 | |
| 358 for(uint i=0; i<ParallelGCThreads; i++) { | |
| 359 q->enqueue(new OldToYoungRootsTask(old_gen, old_top, i)); | |
| 360 } | |
| 361 | |
| 362 q->enqueue(new SerialOldToYoungRootsTask(perm_gen, perm_top)); | |
| 363 | |
| 364 q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::universe)); | |
| 365 q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::jni_handles)); | |
| 366 // We scan the thread roots in parallel | |
| 367 Threads::create_thread_roots_tasks(q); | |
| 368 q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::object_synchronizer)); | |
| 369 q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::flat_profiler)); | |
| 370 q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::management)); | |
| 371 q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::system_dictionary)); | |
| 372 q->enqueue(new ScavengeRootsTask(ScavengeRootsTask::jvmti)); | |
| 373 | |
| 374 ParallelTaskTerminator terminator( | |
| 375 gc_task_manager()->workers(), | |
| 376 promotion_manager->depth_first() ? | |
| 377 (TaskQueueSetSuper*) promotion_manager->stack_array_depth() | |
| 378 : (TaskQueueSetSuper*) promotion_manager->stack_array_breadth()); | |
| 379 if (ParallelGCThreads>1) { | |
| 380 for (uint j=0; j<ParallelGCThreads; j++) { | |
| 381 q->enqueue(new StealTask(&terminator)); | |
| 382 } | |
| 383 } | |
| 384 | |
| 385 gc_task_manager()->execute_and_wait(q); | |
| 386 } | |
| 387 | |
| 388 scavenge_midpoint.update(); | |
| 389 | |
| 390 // Process reference objects discovered during scavenge | |
| 391 { | |
| 392 #ifdef COMPILER2 | |
| 393 ReferencePolicy *soft_ref_policy = new LRUMaxHeapPolicy(); | |
| 394 #else | |
| 395 ReferencePolicy *soft_ref_policy = new LRUCurrentHeapPolicy(); | |
| 396 #endif // COMPILER2 | |
| 397 | |
| 398 PSKeepAliveClosure keep_alive(promotion_manager); | |
| 399 PSEvacuateFollowersClosure evac_followers(promotion_manager); | |
| 400 assert(soft_ref_policy != NULL,"No soft reference policy"); | |
| 401 if (reference_processor()->processing_is_mt()) { | |
| 402 PSRefProcTaskExecutor task_executor; | |
| 403 reference_processor()->process_discovered_references( | |
| 404 soft_ref_policy, &_is_alive_closure, &keep_alive, &evac_followers, | |
| 405 &task_executor); | |
| 406 } else { | |
| 407 reference_processor()->process_discovered_references( | |
| 408 soft_ref_policy, &_is_alive_closure, &keep_alive, &evac_followers, | |
| 409 NULL); | |
| 410 } | |
| 411 } | |
| 412 | |
| 413 // Enqueue reference objects discovered during scavenge. | |
| 414 if (reference_processor()->processing_is_mt()) { | |
| 415 PSRefProcTaskExecutor task_executor; | |
| 416 reference_processor()->enqueue_discovered_references(&task_executor); | |
| 417 } else { | |
| 418 reference_processor()->enqueue_discovered_references(NULL); | |
| 419 } | |
| 420 | |
| 421 // Finally, flush the promotion_manager's labs, and deallocate its stacks. | |
| 422 assert(promotion_manager->claimed_stack_empty(), "Sanity"); | |
| 423 PSPromotionManager::post_scavenge(); | |
| 424 | |
| 425 promotion_failure_occurred = promotion_failed(); | |
| 426 if (promotion_failure_occurred) { | |
| 427 clean_up_failed_promotion(); | |
| 428 if (PrintGC) { | |
| 429 gclog_or_tty->print("--"); | |
| 430 } | |
| 431 } | |
| 432 | |
| 433 // Let the size policy know we're done. Note that we count promotion | |
| 434 // failure cleanup time as part of the collection (otherwise, we're | |
| 435 // implicitly saying it's mutator time). | |
| 436 size_policy->minor_collection_end(gc_cause); | |
| 437 | |
| 438 if (!promotion_failure_occurred) { | |
| 439 // Swap the survivor spaces. | |
| 440 young_gen->eden_space()->clear(); | |
| 441 young_gen->from_space()->clear(); | |
| 442 young_gen->swap_spaces(); | |
| 443 | |
| 444 size_t survived = young_gen->from_space()->used_in_bytes(); | |
| 445 size_t promoted = old_gen->used_in_bytes() - old_gen_used_before; | |
| 446 size_policy->update_averages(_survivor_overflow, survived, promoted); | |
| 447 | |
| 448 if (UseAdaptiveSizePolicy) { | |
| 449 // Calculate the new survivor size and tenuring threshold | |
| 450 | |
| 451 if (PrintAdaptiveSizePolicy) { | |
| 452 gclog_or_tty->print("AdaptiveSizeStart: "); | |
| 453 gclog_or_tty->stamp(); | |
| 454 gclog_or_tty->print_cr(" collection: %d ", | |
| 455 heap->total_collections()); | |
| 456 | |
| 457 if (Verbose) { | |
| 458 gclog_or_tty->print("old_gen_capacity: %d young_gen_capacity: %d" | |
| 459 " perm_gen_capacity: %d ", | |
| 460 old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes(), | |
| 461 perm_gen->capacity_in_bytes()); | |
| 462 } | |
| 463 } | |
| 464 | |
| 465 | |
| 466 if (UsePerfData) { | |
| 467 PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); | |
| 468 counters->update_old_eden_size( | |
| 469 size_policy->calculated_eden_size_in_bytes()); | |
| 470 counters->update_old_promo_size( | |
| 471 size_policy->calculated_promo_size_in_bytes()); | |
| 472 counters->update_old_capacity(old_gen->capacity_in_bytes()); | |
| 473 counters->update_young_capacity(young_gen->capacity_in_bytes()); | |
| 474 counters->update_survived(survived); | |
| 475 counters->update_promoted(promoted); | |
| 476 counters->update_survivor_overflowed(_survivor_overflow); | |
| 477 } | |
| 478 | |
| 479 size_t survivor_limit = | |
| 480 size_policy->max_survivor_size(young_gen->max_size()); | |
| 481 _tenuring_threshold = | |
| 482 size_policy->compute_survivor_space_size_and_threshold( | |
| 483 _survivor_overflow, | |
| 484 _tenuring_threshold, | |
| 485 survivor_limit); | |
| 486 | |
| 487 if (PrintTenuringDistribution) { | |
| 488 gclog_or_tty->cr(); | |
| 489 gclog_or_tty->print_cr("Desired survivor size %ld bytes, new threshold %d (max %d)", | |
| 490 size_policy->calculated_survivor_size_in_bytes(), | |
| 491 _tenuring_threshold, MaxTenuringThreshold); | |
| 492 } | |
| 493 | |
| 494 if (UsePerfData) { | |
| 495 PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); | |
| 496 counters->update_tenuring_threshold(_tenuring_threshold); | |
| 497 counters->update_survivor_size_counters(); | |
| 498 } | |
| 499 | |
| 500 // Do call at minor collections? | |
| 501 // Don't check if the size_policy is ready at this | |
| 502 // level. Let the size_policy check that internally. | |
| 503 if (UseAdaptiveSizePolicy && | |
| 504 UseAdaptiveGenerationSizePolicyAtMinorCollection && | |
| 505 ((gc_cause != GCCause::_java_lang_system_gc) || | |
| 506 UseAdaptiveSizePolicyWithSystemGC)) { | |
| 507 | |
| 508 // Calculate optimial free space amounts | |
| 509 assert(young_gen->max_size() > | |
| 510 young_gen->from_space()->capacity_in_bytes() + | |
| 511 young_gen->to_space()->capacity_in_bytes(), | |
| 512 "Sizes of space in young gen are out-of-bounds"); | |
| 513 size_t max_eden_size = young_gen->max_size() - | |
| 514 young_gen->from_space()->capacity_in_bytes() - | |
| 515 young_gen->to_space()->capacity_in_bytes(); | |
| 516 size_policy->compute_generation_free_space(young_gen->used_in_bytes(), | |
| 517 young_gen->eden_space()->used_in_bytes(), | |
| 518 old_gen->used_in_bytes(), | |
| 519 perm_gen->used_in_bytes(), | |
| 520 young_gen->eden_space()->capacity_in_bytes(), | |
| 521 old_gen->max_gen_size(), | |
| 522 max_eden_size, | |
| 523 false /* full gc*/, | |
| 524 gc_cause); | |
| 525 | |
| 526 } | |
| 527 // Resize the young generation at every collection | |
| 528 // even if new sizes have not been calculated. This is | |
| 529 // to allow resizes that may have been inhibited by the | |
| 530 // relative location of the "to" and "from" spaces. | |
| 531 | |
| 532 // Resizing the old gen at minor collects can cause increases | |
| 533 // that don't feed back to the generation sizing policy until | |
| 534 // a major collection. Don't resize the old gen here. | |
| 535 | |
| 536 heap->resize_young_gen(size_policy->calculated_eden_size_in_bytes(), | |
| 537 size_policy->calculated_survivor_size_in_bytes()); | |
| 538 | |
| 539 if (PrintAdaptiveSizePolicy) { | |
| 540 gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ", | |
| 541 heap->total_collections()); | |
| 542 } | |
| 543 } | |
| 544 | |
| 545 // Update the structure of the eden. With NUMA-eden CPU hotplugging or offlining can | |
| 546 // cause the change of the heap layout. Make sure eden is reshaped if that's the case. | |
| 547 // Also update() will case adaptive NUMA chunk resizing. | |
| 548 assert(young_gen->eden_space()->is_empty(), "eden space should be empty now"); | |
| 549 young_gen->eden_space()->update(); | |
| 550 | |
| 551 heap->gc_policy_counters()->update_counters(); | |
| 552 | |
| 553 heap->resize_all_tlabs(); | |
| 554 | |
| 555 assert(young_gen->to_space()->is_empty(), "to space should be empty now"); | |
| 556 } | |
| 557 | |
| 558 COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); | |
| 559 | |
| 560 NOT_PRODUCT(reference_processor()->verify_no_references_recorded()); | |
| 561 | |
| 562 // Re-verify object start arrays | |
| 563 if (VerifyObjectStartArray && | |
| 564 VerifyAfterGC) { | |
| 565 old_gen->verify_object_start_array(); | |
| 566 perm_gen->verify_object_start_array(); | |
| 567 } | |
| 568 | |
| 569 // Verify all old -> young cards are now precise | |
| 570 if (VerifyRememberedSets) { | |
| 571 // Precise verification will give false positives. Until this is fixed, | |
| 572 // use imprecise verification. | |
| 573 // CardTableExtension::verify_all_young_refs_precise(); | |
| 574 CardTableExtension::verify_all_young_refs_imprecise(); | |
| 575 } | |
| 576 | |
| 577 if (TraceGen0Time) accumulated_time()->stop(); | |
| 578 | |
| 579 if (PrintGC) { | |
| 580 if (PrintGCDetails) { | |
| 581 // Don't print a GC timestamp here. This is after the GC so | |
| 582 // would be confusing. | |
| 583 young_gen->print_used_change(young_gen_used_before); | |
| 584 } | |
| 585 heap->print_heap_change(prev_used); | |
| 586 } | |
| 587 | |
| 588 // Track memory usage and detect low memory | |
| 589 MemoryService::track_memory_usage(); | |
| 590 heap->update_counters(); | |
| 591 } | |
| 592 | |
| 593 if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) { | |
| 594 HandleMark hm; // Discard invalid handles created during verification | |
| 595 gclog_or_tty->print(" VerifyAfterGC:"); | |
| 596 Universe::verify(false); | |
| 597 } | |
| 598 | |
| 599 if (PrintHeapAtGC) { | |
| 600 Universe::print_heap_after_gc(); | |
| 601 } | |
| 602 | |
| 603 scavenge_exit.update(); | |
| 604 | |
| 605 if (PrintGCTaskTimeStamps) { | |
| 606 tty->print_cr("VM-Thread " INT64_FORMAT " " INT64_FORMAT " " INT64_FORMAT, | |
| 607 scavenge_entry.ticks(), scavenge_midpoint.ticks(), | |
| 608 scavenge_exit.ticks()); | |
| 609 gc_task_manager()->print_task_time_stamps(); | |
| 610 } | |
| 611 | |
| 612 return !promotion_failure_occurred; | |
| 613 } | |
| 614 | |
| 615 // This method iterates over all objects in the young generation, | |
| 616 // unforwarding markOops. It then restores any preserved mark oops, | |
| 617 // and clears the _preserved_mark_stack. | |
| 618 void PSScavenge::clean_up_failed_promotion() { | |
| 619 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 620 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 621 assert(promotion_failed(), "Sanity"); | |
| 622 | |
| 623 PSYoungGen* young_gen = heap->young_gen(); | |
| 624 | |
| 625 { | |
| 626 ResourceMark rm; | |
| 627 | |
| 628 // Unforward all pointers in the young gen. | |
| 629 PSPromotionFailedClosure unforward_closure; | |
| 630 young_gen->object_iterate(&unforward_closure); | |
| 631 | |
| 632 if (PrintGC && Verbose) { | |
| 633 gclog_or_tty->print_cr("Restoring %d marks", | |
| 634 _preserved_oop_stack->length()); | |
| 635 } | |
| 636 | |
| 637 // Restore any saved marks. | |
| 638 for (int i=0; i < _preserved_oop_stack->length(); i++) { | |
| 639 oop obj = _preserved_oop_stack->at(i); | |
| 640 markOop mark = _preserved_mark_stack->at(i); | |
| 641 obj->set_mark(mark); | |
| 642 } | |
| 643 | |
| 644 // Deallocate the preserved mark and oop stacks. | |
| 645 // The stacks were allocated as CHeap objects, so | |
| 646 // we must call delete to prevent mem leaks. | |
| 647 delete _preserved_mark_stack; | |
| 648 _preserved_mark_stack = NULL; | |
| 649 delete _preserved_oop_stack; | |
| 650 _preserved_oop_stack = NULL; | |
| 651 } | |
| 652 | |
| 653 // Reset the PromotionFailureALot counters. | |
| 654 NOT_PRODUCT(Universe::heap()->reset_promotion_should_fail();) | |
| 655 } | |
| 656 | |
| 657 // This method is called whenever an attempt to promote an object | |
| 658 // fails. Some markOops will need preserving, some will not. Note | |
| 659 // that the entire eden is traversed after a failed promotion, with | |
| 660 // all forwarded headers replaced by the default markOop. This means | |
| 661 // it is not neccessary to preserve most markOops. | |
| 662 void PSScavenge::oop_promotion_failed(oop obj, markOop obj_mark) { | |
| 663 if (_preserved_mark_stack == NULL) { | |
| 664 ThreadCritical tc; // Lock and retest | |
| 665 if (_preserved_mark_stack == NULL) { | |
| 666 assert(_preserved_oop_stack == NULL, "Sanity"); | |
| 667 _preserved_mark_stack = new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true); | |
| 668 _preserved_oop_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true); | |
| 669 } | |
| 670 } | |
| 671 | |
| 672 // Because we must hold the ThreadCritical lock before using | |
| 673 // the stacks, we should be safe from observing partial allocations, | |
| 674 // which are also guarded by the ThreadCritical lock. | |
| 675 if (obj_mark->must_be_preserved_for_promotion_failure(obj)) { | |
| 676 ThreadCritical tc; | |
| 677 _preserved_oop_stack->push(obj); | |
| 678 _preserved_mark_stack->push(obj_mark); | |
| 679 } | |
| 680 } | |
| 681 | |
| 682 bool PSScavenge::should_attempt_scavenge() { | |
| 683 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 684 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 685 PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); | |
| 686 | |
| 687 if (UsePerfData) { | |
| 688 counters->update_scavenge_skipped(not_skipped); | |
| 689 } | |
| 690 | |
| 691 PSYoungGen* young_gen = heap->young_gen(); | |
| 692 PSOldGen* old_gen = heap->old_gen(); | |
| 693 | |
| 694 if (!ScavengeWithObjectsInToSpace) { | |
| 695 // Do not attempt to promote unless to_space is empty | |
| 696 if (!young_gen->to_space()->is_empty()) { | |
| 697 _consecutive_skipped_scavenges++; | |
| 698 if (UsePerfData) { | |
| 699 counters->update_scavenge_skipped(to_space_not_empty); | |
| 700 } | |
| 701 return false; | |
| 702 } | |
| 703 } | |
| 704 | |
| 705 // Test to see if the scavenge will likely fail. | |
| 706 PSAdaptiveSizePolicy* policy = heap->size_policy(); | |
| 707 | |
| 708 // A similar test is done in the policy's should_full_GC(). If this is | |
| 709 // changed, decide if that test should also be changed. | |
| 710 size_t avg_promoted = (size_t) policy->padded_average_promoted_in_bytes(); | |
| 711 size_t promotion_estimate = MIN2(avg_promoted, young_gen->used_in_bytes()); | |
| 712 bool result = promotion_estimate < old_gen->free_in_bytes(); | |
| 713 | |
| 714 if (PrintGCDetails && Verbose) { | |
| 715 gclog_or_tty->print(result ? " do scavenge: " : " skip scavenge: "); | |
| 716 gclog_or_tty->print_cr(" average_promoted " SIZE_FORMAT | |
| 717 " padded_average_promoted " SIZE_FORMAT | |
| 718 " free in old gen " SIZE_FORMAT, | |
| 719 (size_t) policy->average_promoted_in_bytes(), | |
| 720 (size_t) policy->padded_average_promoted_in_bytes(), | |
| 721 old_gen->free_in_bytes()); | |
| 722 if (young_gen->used_in_bytes() < | |
| 723 (size_t) policy->padded_average_promoted_in_bytes()) { | |
| 724 gclog_or_tty->print_cr(" padded_promoted_average is greater" | |
| 725 " than maximum promotion = " SIZE_FORMAT, young_gen->used_in_bytes()); | |
| 726 } | |
| 727 } | |
| 728 | |
| 729 if (result) { | |
| 730 _consecutive_skipped_scavenges = 0; | |
| 731 } else { | |
| 732 _consecutive_skipped_scavenges++; | |
| 733 if (UsePerfData) { | |
| 734 counters->update_scavenge_skipped(promoted_too_large); | |
| 735 } | |
| 736 } | |
| 737 return result; | |
| 738 } | |
| 739 | |
| 740 // Used to add tasks | |
| 741 GCTaskManager* const PSScavenge::gc_task_manager() { | |
| 742 assert(ParallelScavengeHeap::gc_task_manager() != NULL, | |
| 743 "shouldn't return NULL"); | |
| 744 return ParallelScavengeHeap::gc_task_manager(); | |
| 745 } | |
| 746 | |
| 747 void PSScavenge::initialize() { | |
| 748 // Arguments must have been parsed | |
| 749 | |
| 750 if (AlwaysTenure) { | |
| 751 _tenuring_threshold = 0; | |
| 752 } else if (NeverTenure) { | |
| 753 _tenuring_threshold = markOopDesc::max_age + 1; | |
| 754 } else { | |
| 755 // We want to smooth out our startup times for the AdaptiveSizePolicy | |
| 756 _tenuring_threshold = (UseAdaptiveSizePolicy) ? InitialTenuringThreshold : | |
| 757 MaxTenuringThreshold; | |
| 758 } | |
| 759 | |
| 760 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
| 761 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); | |
| 762 | |
| 763 PSYoungGen* young_gen = heap->young_gen(); | |
| 764 PSOldGen* old_gen = heap->old_gen(); | |
| 765 PSPermGen* perm_gen = heap->perm_gen(); | |
| 766 | |
| 767 // Set boundary between young_gen and old_gen | |
| 768 assert(perm_gen->reserved().end() <= old_gen->object_space()->bottom(), | |
| 769 "perm above old"); | |
| 770 assert(old_gen->reserved().end() <= young_gen->eden_space()->bottom(), | |
| 771 "old above young"); | |
| 772 _young_generation_boundary = young_gen->eden_space()->bottom(); | |
| 773 | |
| 774 // Initialize ref handling object for scavenging. | |
| 775 MemRegion mr = young_gen->reserved(); | |
| 776 _ref_processor = ReferenceProcessor::create_ref_processor( | |
| 777 mr, // span | |
| 778 true, // atomic_discovery | |
| 779 true, // mt_discovery | |
| 780 NULL, // is_alive_non_header | |
| 781 ParallelGCThreads, | |
| 782 ParallelRefProcEnabled); | |
| 783 | |
| 784 // Cache the cardtable | |
| 785 BarrierSet* bs = Universe::heap()->barrier_set(); | |
| 786 assert(bs->kind() == BarrierSet::CardTableModRef, "Wrong barrier set kind"); | |
| 787 _card_table = (CardTableExtension*)bs; | |
| 788 | |
| 789 _counters = new CollectorCounters("PSScavenge", 0); | |
| 790 } |