| /* |
| * Copyright (c) 2002, 2024, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "classfile/classLoaderDataGraph.hpp" |
| #include "classfile/stringTable.hpp" |
| #include "code/codeCache.hpp" |
| #include "compiler/oopMap.hpp" |
| #include "gc/parallel/parallelScavengeHeap.hpp" |
| #include "gc/parallel/psAdaptiveSizePolicy.hpp" |
| #include "gc/parallel/psClosure.inline.hpp" |
| #include "gc/parallel/psCompactionManager.hpp" |
| #include "gc/parallel/psParallelCompact.inline.hpp" |
| #include "gc/parallel/psPromotionManager.inline.hpp" |
| #include "gc/parallel/psRootType.hpp" |
| #include "gc/parallel/psScavenge.inline.hpp" |
| #include "gc/shared/gcCause.hpp" |
| #include "gc/shared/gcHeapSummary.hpp" |
| #include "gc/shared/gcId.hpp" |
| #include "gc/shared/gcLocker.hpp" |
| #include "gc/shared/gcTimer.hpp" |
| #include "gc/shared/gcTrace.hpp" |
| #include "gc/shared/gcTraceTime.inline.hpp" |
| #include "gc/shared/isGCActiveMark.hpp" |
| #include "gc/shared/oopStorage.inline.hpp" |
| #include "gc/shared/oopStorageSetParState.inline.hpp" |
| #include "gc/shared/oopStorageParState.inline.hpp" |
| #include "gc/shared/referencePolicy.hpp" |
| #include "gc/shared/referenceProcessor.hpp" |
| #include "gc/shared/referenceProcessorPhaseTimes.hpp" |
| #include "gc/shared/scavengableNMethods.hpp" |
| #include "gc/shared/spaceDecorator.inline.hpp" |
| #include "gc/shared/taskTerminator.hpp" |
| #include "gc/shared/weakProcessor.inline.hpp" |
| #include "gc/shared/workerPolicy.hpp" |
| #include "gc/shared/workerThread.hpp" |
| #include "gc/shared/workerUtils.hpp" |
| #include "memory/iterator.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "memory/universe.hpp" |
| #include "logging/log.hpp" |
| #include "oops/access.inline.hpp" |
| #include "oops/compressedOops.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/handles.inline.hpp" |
| #include "runtime/threadCritical.hpp" |
| #include "runtime/threads.hpp" |
| #include "runtime/vmThread.hpp" |
| #include "runtime/vmOperations.hpp" |
| #include "services/memoryService.hpp" |
| #include "utilities/stack.inline.hpp" |
| |
| SpanSubjectToDiscoveryClosure PSScavenge::_span_based_discoverer; |
| ReferenceProcessor* PSScavenge::_ref_processor = nullptr; |
| PSCardTable* PSScavenge::_card_table = nullptr; |
| bool PSScavenge::_survivor_overflow = false; |
| uint PSScavenge::_tenuring_threshold = 0; |
| HeapWord* PSScavenge::_young_generation_boundary = nullptr; |
| uintptr_t PSScavenge::_young_generation_boundary_compressed = 0; |
| elapsedTimer PSScavenge::_accumulated_time; |
| STWGCTimer PSScavenge::_gc_timer; |
| ParallelScavengeTracer PSScavenge::_gc_tracer; |
| CollectorCounters* PSScavenge::_counters = nullptr; |
| |
| static void scavenge_roots_work(ParallelRootType::Value root_type, uint worker_id) { |
| assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc"); |
| |
| PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(worker_id); |
| PSPromoteRootsClosure roots_to_old_closure(pm); |
| |
| switch (root_type) { |
| case ParallelRootType::class_loader_data: |
| { |
| PSScavengeCLDClosure cld_closure(pm); |
| ClassLoaderDataGraph::cld_do(&cld_closure); |
| } |
| break; |
| |
| case ParallelRootType::code_cache: |
| { |
| MarkingCodeBlobClosure code_closure(&roots_to_old_closure, CodeBlobToOopClosure::FixRelocations, false /* keepalive nmethods */); |
| ScavengableNMethods::nmethods_do(&code_closure); |
| } |
| break; |
| |
| case ParallelRootType::sentinel: |
| DEBUG_ONLY(default:) // DEBUG_ONLY hack will create compile error on release builds (-Wswitch) and runtime check on debug builds |
| fatal("Bad enumeration value: %u", root_type); |
| break; |
| } |
| |
| // Do the real work |
| pm->drain_stacks(false); |
| } |
| |
| static void steal_work(TaskTerminator& terminator, uint worker_id) { |
| assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc"); |
| |
| PSPromotionManager* pm = |
| PSPromotionManager::gc_thread_promotion_manager(worker_id); |
| pm->drain_stacks(true); |
| guarantee(pm->stacks_empty(), |
| "stacks should be empty at this point"); |
| |
| while (true) { |
| ScannerTask task; |
| if (PSPromotionManager::steal_depth(worker_id, task)) { |
| TASKQUEUE_STATS_ONLY(pm->record_steal(task)); |
| pm->process_popped_location_depth(task); |
| pm->drain_stacks_depth(true); |
| } else { |
| if (terminator.offer_termination()) { |
| break; |
| } |
| } |
| } |
| guarantee(pm->stacks_empty(), "stacks should be empty at this point"); |
| } |
| |
| // Define before use |
| class PSIsAliveClosure: public BoolObjectClosure { |
| public: |
| bool do_object_b(oop p) { |
| return (!PSScavenge::is_obj_in_young(p)) || p->is_forwarded(); |
| } |
| }; |
| |
| PSIsAliveClosure PSScavenge::_is_alive_closure; |
| |
| class PSKeepAliveClosure: public OopClosure { |
| protected: |
| MutableSpace* _to_space; |
| PSPromotionManager* _promotion_manager; |
| |
| public: |
| PSKeepAliveClosure(PSPromotionManager* pm) : _promotion_manager(pm) { |
| ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); |
| _to_space = heap->young_gen()->to_space(); |
| |
| assert(_promotion_manager != nullptr, "Sanity"); |
| } |
| |
| template <class T> void do_oop_work(T* p) { |
| #ifdef ASSERT |
| // Referent must be non-null and in from-space |
| oop obj = RawAccess<IS_NOT_NULL>::oop_load(p); |
| assert(oopDesc::is_oop(obj), "referent must be an oop"); |
| assert(PSScavenge::is_obj_in_young(obj), "must be in young-gen"); |
| assert(!PSScavenge::is_obj_in_to_space(obj), "must be in from-space"); |
| #endif |
| |
| _promotion_manager->copy_and_push_safe_barrier</*promote_immediately=*/false>(p); |
| } |
| virtual void do_oop(oop* p) { PSKeepAliveClosure::do_oop_work(p); } |
| virtual void do_oop(narrowOop* p) { PSKeepAliveClosure::do_oop_work(p); } |
| }; |
| |
| class PSEvacuateFollowersClosure: public VoidClosure { |
| private: |
| PSPromotionManager* _promotion_manager; |
| TaskTerminator* _terminator; |
| uint _worker_id; |
| |
| public: |
| PSEvacuateFollowersClosure(PSPromotionManager* pm, TaskTerminator* terminator, uint worker_id) |
| : _promotion_manager(pm), _terminator(terminator), _worker_id(worker_id) {} |
| |
| virtual void do_void() { |
| assert(_promotion_manager != nullptr, "Sanity"); |
| _promotion_manager->drain_stacks(true); |
| guarantee(_promotion_manager->stacks_empty(), |
| "stacks should be empty at this point"); |
| |
| if (_terminator != nullptr) { |
| steal_work(*_terminator, _worker_id); |
| } |
| } |
| }; |
| |
| class ParallelScavengeRefProcProxyTask : public RefProcProxyTask { |
| TaskTerminator _terminator; |
| |
| public: |
| ParallelScavengeRefProcProxyTask(uint max_workers) |
| : RefProcProxyTask("ParallelScavengeRefProcProxyTask", max_workers), |
| _terminator(max_workers, ParCompactionManager::oop_task_queues()) {} |
| |
| void work(uint worker_id) override { |
| assert(worker_id < _max_workers, "sanity"); |
| PSPromotionManager* promotion_manager = (_tm == RefProcThreadModel::Single) ? PSPromotionManager::vm_thread_promotion_manager() : PSPromotionManager::gc_thread_promotion_manager(worker_id); |
| PSIsAliveClosure is_alive; |
| PSKeepAliveClosure keep_alive(promotion_manager); |
| BarrierEnqueueDiscoveredFieldClosure enqueue; |
| PSEvacuateFollowersClosure complete_gc(promotion_manager, (_marks_oops_alive && _tm == RefProcThreadModel::Multi) ? &_terminator : nullptr, worker_id);; |
| _rp_task->rp_work(worker_id, &is_alive, &keep_alive, &enqueue, &complete_gc); |
| } |
| |
| void prepare_run_task_hook() override { |
| _terminator.reset_for_reuse(_queue_count); |
| } |
| }; |
| |
| // This method contains all heap specific policy for invoking scavenge. |
| // PSScavenge::invoke_no_policy() will do nothing but attempt to |
| // scavenge. It will not clean up after failed promotions, bail out if |
| // we've exceeded policy time limits, or any other special behavior. |
| // All such policy should be placed here. |
| // |
| // Note that this method should only be called from the vm_thread while |
| // at a safepoint! |
| bool PSScavenge::invoke() { |
| assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); |
| assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); |
| assert(!ParallelScavengeHeap::heap()->is_gc_active(), "not reentrant"); |
| |
| ParallelScavengeHeap* const heap = ParallelScavengeHeap::heap(); |
| PSAdaptiveSizePolicy* policy = heap->size_policy(); |
| IsGCActiveMark mark; |
| |
| const bool scavenge_done = PSScavenge::invoke_no_policy(); |
| const bool need_full_gc = !scavenge_done; |
| bool full_gc_done = false; |
| |
| if (UsePerfData) { |
| PSGCAdaptivePolicyCounters* const counters = heap->gc_policy_counters(); |
| const int ffs_val = need_full_gc ? full_follows_scavenge : not_skipped; |
| counters->update_full_follows_scavenge(ffs_val); |
| } |
| |
| if (need_full_gc) { |
| GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy); |
| SoftRefPolicy* srp = heap->soft_ref_policy(); |
| const bool clear_all_softrefs = srp->should_clear_all_soft_refs(); |
| |
| full_gc_done = PSParallelCompact::invoke_no_policy(clear_all_softrefs); |
| } |
| |
| return full_gc_done; |
| } |
| |
| class PSThreadRootsTaskClosure : public ThreadClosure { |
| uint _worker_id; |
| public: |
| PSThreadRootsTaskClosure(uint worker_id) : _worker_id(worker_id) { } |
| virtual void do_thread(Thread* thread) { |
| assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc"); |
| |
| PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(_worker_id); |
| PSScavengeRootsClosure roots_closure(pm); |
| MarkingCodeBlobClosure roots_in_blobs(&roots_closure, CodeBlobToOopClosure::FixRelocations, false /* keepalive nmethods */); |
| |
| thread->oops_do(&roots_closure, &roots_in_blobs); |
| |
| // Do the real work |
| pm->drain_stacks(false); |
| } |
| }; |
| |
| class ScavengeRootsTask : public WorkerTask { |
| StrongRootsScope _strong_roots_scope; // needed for Threads::possibly_parallel_threads_do |
| OopStorageSetStrongParState<false /* concurrent */, false /* is_const */> _oop_storage_strong_par_state; |
| SequentialSubTasksDone _subtasks; |
| PSOldGen* _old_gen; |
| HeapWord* _gen_top; |
| uint _active_workers; |
| bool _is_old_gen_empty; |
| TaskTerminator _terminator; |
| |
| public: |
| ScavengeRootsTask(PSOldGen* old_gen, |
| uint active_workers) : |
| WorkerTask("ScavengeRootsTask"), |
| _strong_roots_scope(active_workers), |
| _subtasks(ParallelRootType::sentinel), |
| _old_gen(old_gen), |
| _gen_top(old_gen->object_space()->top()), |
| _active_workers(active_workers), |
| _is_old_gen_empty(old_gen->object_space()->is_empty()), |
| _terminator(active_workers, PSPromotionManager::vm_thread_promotion_manager()->stack_array_depth()) { |
| assert(_old_gen != nullptr, "Sanity"); |
| |
| if (!_is_old_gen_empty) { |
| PSCardTable* card_table = ParallelScavengeHeap::heap()->card_table(); |
| card_table->pre_scavenge(_old_gen->object_space()->bottom(), active_workers); |
| } |
| } |
| |
| virtual void work(uint worker_id) { |
| assert(worker_id < _active_workers, "Sanity"); |
| ResourceMark rm; |
| |
| if (!_is_old_gen_empty) { |
| // There are only old-to-young pointers if there are objects |
| // in the old gen. |
| { |
| PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(worker_id); |
| PSCardTable* card_table = ParallelScavengeHeap::heap()->card_table(); |
| |
| // The top of the old gen changes during scavenge when objects are promoted. |
| card_table->scavenge_contents_parallel(_old_gen->start_array(), |
| _old_gen->object_space()->bottom(), |
| _gen_top, |
| pm, |
| worker_id, |
| _active_workers); |
| |
| // Do the real work |
| pm->drain_stacks(false); |
| } |
| } |
| |
| for (uint root_type = 0; _subtasks.try_claim_task(root_type); /* empty */ ) { |
| scavenge_roots_work(static_cast<ParallelRootType::Value>(root_type), worker_id); |
| } |
| |
| PSThreadRootsTaskClosure closure(worker_id); |
| Threads::possibly_parallel_threads_do(true /* is_par */, &closure); |
| |
| // Scavenge OopStorages |
| { |
| PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(worker_id); |
| PSScavengeRootsClosure closure(pm); |
| _oop_storage_strong_par_state.oops_do(&closure); |
| // Do the real work |
| pm->drain_stacks(false); |
| } |
| |
| // If active_workers can exceed 1, add a steal_work(). |
| // PSPromotionManager::drain_stacks_depth() does not fully drain its |
| // stacks and expects a steal_work() to complete the draining if |
| // ParallelGCThreads is > 1. |
| |
| if (_active_workers > 1) { |
| steal_work(_terminator, worker_id); |
| } |
| } |
| }; |
| |
| // This method contains no policy. You should probably |
| // be calling invoke() instead. |
| bool PSScavenge::invoke_no_policy() { |
| assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); |
| assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); |
| |
| _gc_timer.register_gc_start(); |
| |
| if (GCLocker::check_active_before_gc()) { |
| return false; |
| } |
| |
| ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); |
| GCCause::Cause gc_cause = heap->gc_cause(); |
| |
| // Check for potential problems. |
| if (!should_attempt_scavenge()) { |
| return false; |
| } |
| |
| GCIdMark gc_id_mark; |
| _gc_tracer.report_gc_start(heap->gc_cause(), _gc_timer.gc_start()); |
| |
| bool promotion_failure_occurred = false; |
| |
| PSYoungGen* young_gen = heap->young_gen(); |
| PSOldGen* old_gen = heap->old_gen(); |
| PSAdaptiveSizePolicy* size_policy = heap->size_policy(); |
| |
| heap->increment_total_collections(); |
| |
| if (AdaptiveSizePolicy::should_update_eden_stats(gc_cause)) { |
| // Gather the feedback data for eden occupancy. |
| young_gen->eden_space()->accumulate_statistics(); |
| } |
| |
| heap->print_heap_before_gc(); |
| heap->trace_heap_before_gc(&_gc_tracer); |
| |
| assert(!NeverTenure || _tenuring_threshold == markWord::max_age + 1, "Sanity"); |
| assert(!AlwaysTenure || _tenuring_threshold == 0, "Sanity"); |
| |
| // Fill in TLABs |
| heap->ensure_parsability(true); // retire TLABs |
| |
| if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) { |
| Universe::verify("Before GC"); |
| } |
| |
| { |
| ResourceMark rm; |
| |
| GCTraceCPUTime tcpu(&_gc_tracer); |
| GCTraceTime(Info, gc) tm("Pause Young", nullptr, gc_cause, true); |
| TraceCollectorStats tcs(counters()); |
| TraceMemoryManagerStats tms(heap->young_gc_manager(), gc_cause, "end of minor GC"); |
| |
| if (log_is_enabled(Debug, gc, heap, exit)) { |
| accumulated_time()->start(); |
| } |
| |
| // Let the size policy know we're starting |
| size_policy->minor_collection_begin(); |
| |
| // Verify the object start arrays. |
| if (VerifyObjectStartArray && |
| VerifyBeforeGC) { |
| old_gen->verify_object_start_array(); |
| } |
| |
| // Verify no unmarked old->young roots |
| if (VerifyRememberedSets) { |
| heap->card_table()->verify_all_young_refs_imprecise(); |
| } |
| |
| assert(young_gen->to_space()->is_empty(), |
| "Attempt to scavenge with live objects in to_space"); |
| young_gen->to_space()->clear(SpaceDecorator::Mangle); |
| |
| #if COMPILER2_OR_JVMCI |
| DerivedPointerTable::clear(); |
| #endif |
| |
| reference_processor()->start_discovery(false /* always_clear */); |
| |
| const PreGenGCValues pre_gc_values = heap->get_pre_gc_values(); |
| |
| // Reset our survivor overflow. |
| set_survivor_overflow(false); |
| |
| const uint active_workers = |
| WorkerPolicy::calc_active_workers(ParallelScavengeHeap::heap()->workers().max_workers(), |
| ParallelScavengeHeap::heap()->workers().active_workers(), |
| Threads::number_of_non_daemon_threads()); |
| ParallelScavengeHeap::heap()->workers().set_active_workers(active_workers); |
| |
| PSPromotionManager::pre_scavenge(); |
| |
| // We'll use the promotion manager again later. |
| PSPromotionManager* promotion_manager = PSPromotionManager::vm_thread_promotion_manager(); |
| { |
| GCTraceTime(Debug, gc, phases) tm("Scavenge", &_gc_timer); |
| |
| ScavengeRootsTask task(old_gen, active_workers); |
| ParallelScavengeHeap::heap()->workers().run_task(&task); |
| } |
| |
| // Process reference objects discovered during scavenge |
| { |
| GCTraceTime(Debug, gc, phases) tm("Reference Processing", &_gc_timer); |
| |
| reference_processor()->set_active_mt_degree(active_workers); |
| ReferenceProcessorStats stats; |
| ReferenceProcessorPhaseTimes pt(&_gc_timer, reference_processor()->max_num_queues()); |
| |
| ParallelScavengeRefProcProxyTask task(reference_processor()->max_num_queues()); |
| stats = reference_processor()->process_discovered_references(task, pt); |
| |
| _gc_tracer.report_gc_reference_stats(stats); |
| pt.print_all_references(); |
| } |
| |
| assert(promotion_manager->stacks_empty(),"stacks should be empty at this point"); |
| |
| { |
| GCTraceTime(Debug, gc, phases) tm("Weak Processing", &_gc_timer); |
| PSAdjustWeakRootsClosure root_closure; |
| WeakProcessor::weak_oops_do(&ParallelScavengeHeap::heap()->workers(), &_is_alive_closure, &root_closure, 1); |
| } |
| |
| // Verify that usage of root_closure didn't copy any objects. |
| assert(promotion_manager->stacks_empty(),"stacks should be empty at this point"); |
| |
| // Finally, flush the promotion_manager's labs, and deallocate its stacks. |
| promotion_failure_occurred = PSPromotionManager::post_scavenge(_gc_tracer); |
| if (promotion_failure_occurred) { |
| clean_up_failed_promotion(); |
| log_info(gc, promotion)("Promotion failed"); |
| } |
| |
| _gc_tracer.report_tenuring_threshold(tenuring_threshold()); |
| |
| // Let the size policy know we're done. Note that we count promotion |
| // failure cleanup time as part of the collection (otherwise, we're |
| // implicitly saying it's mutator time). |
| size_policy->minor_collection_end(gc_cause); |
| |
| if (!promotion_failure_occurred) { |
| // Swap the survivor spaces. |
| young_gen->eden_space()->clear(SpaceDecorator::Mangle); |
| young_gen->from_space()->clear(SpaceDecorator::Mangle); |
| young_gen->swap_spaces(); |
| |
| size_t survived = young_gen->from_space()->used_in_bytes(); |
| size_t promoted = old_gen->used_in_bytes() - pre_gc_values.old_gen_used(); |
| size_policy->update_averages(_survivor_overflow, survived, promoted); |
| |
| // A successful scavenge should restart the GC time limit count which is |
| // for full GC's. |
| size_policy->reset_gc_overhead_limit_count(); |
| if (UseAdaptiveSizePolicy) { |
| // Calculate the new survivor size and tenuring threshold |
| |
| log_debug(gc, ergo)("AdaptiveSizeStart: collection: %d ", heap->total_collections()); |
| log_trace(gc, ergo)("old_gen_capacity: " SIZE_FORMAT " young_gen_capacity: " SIZE_FORMAT, |
| old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes()); |
| |
| if (UsePerfData) { |
| PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); |
| counters->update_old_eden_size( |
| size_policy->calculated_eden_size_in_bytes()); |
| counters->update_old_promo_size( |
| size_policy->calculated_promo_size_in_bytes()); |
| counters->update_old_capacity(old_gen->capacity_in_bytes()); |
| counters->update_young_capacity(young_gen->capacity_in_bytes()); |
| counters->update_survived(survived); |
| counters->update_promoted(promoted); |
| counters->update_survivor_overflowed(_survivor_overflow); |
| } |
| |
| size_t max_young_size = young_gen->max_gen_size(); |
| |
| // Deciding a free ratio in the young generation is tricky, so if |
| // MinHeapFreeRatio or MaxHeapFreeRatio are in use (implicating |
| // that the old generation size may have been limited because of them) we |
| // should then limit our young generation size using NewRatio to have it |
| // follow the old generation size. |
| if (MinHeapFreeRatio != 0 || MaxHeapFreeRatio != 100) { |
| max_young_size = MIN2(old_gen->capacity_in_bytes() / NewRatio, |
| young_gen->max_gen_size()); |
| } |
| |
| size_t survivor_limit = |
| size_policy->max_survivor_size(max_young_size); |
| _tenuring_threshold = |
| size_policy->compute_survivor_space_size_and_threshold( |
| _survivor_overflow, |
| _tenuring_threshold, |
| survivor_limit); |
| |
| log_debug(gc, age)("Desired survivor size " SIZE_FORMAT " bytes, new threshold %u (max threshold " UINTX_FORMAT ")", |
| size_policy->calculated_survivor_size_in_bytes(), |
| _tenuring_threshold, MaxTenuringThreshold); |
| |
| if (UsePerfData) { |
| PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); |
| counters->update_tenuring_threshold(_tenuring_threshold); |
| counters->update_survivor_size_counters(); |
| } |
| |
| // Do call at minor collections? |
| // Don't check if the size_policy is ready at this |
| // level. Let the size_policy check that internally. |
| if (UseAdaptiveGenerationSizePolicyAtMinorCollection && |
| AdaptiveSizePolicy::should_update_eden_stats(gc_cause)) { |
| // Calculate optimal free space amounts |
| assert(young_gen->max_gen_size() > |
| young_gen->from_space()->capacity_in_bytes() + |
| young_gen->to_space()->capacity_in_bytes(), |
| "Sizes of space in young gen are out-of-bounds"); |
| |
| size_t young_live = young_gen->used_in_bytes(); |
| size_t eden_live = young_gen->eden_space()->used_in_bytes(); |
| size_t cur_eden = young_gen->eden_space()->capacity_in_bytes(); |
| size_t max_old_gen_size = old_gen->max_gen_size(); |
| size_t max_eden_size = max_young_size - |
| young_gen->from_space()->capacity_in_bytes() - |
| young_gen->to_space()->capacity_in_bytes(); |
| |
| // Used for diagnostics |
| size_policy->clear_generation_free_space_flags(); |
| |
| size_policy->compute_eden_space_size(young_live, |
| eden_live, |
| cur_eden, |
| max_eden_size, |
| false /* not full gc*/); |
| |
| size_policy->check_gc_overhead_limit(eden_live, |
| max_old_gen_size, |
| max_eden_size, |
| false /* not full gc*/, |
| gc_cause, |
| heap->soft_ref_policy()); |
| |
| size_policy->decay_supplemental_growth(false /* not full gc*/); |
| } |
| // Resize the young generation at every collection |
| // even if new sizes have not been calculated. This is |
| // to allow resizes that may have been inhibited by the |
| // relative location of the "to" and "from" spaces. |
| |
| // Resizing the old gen at young collections can cause increases |
| // that don't feed back to the generation sizing policy until |
| // a full collection. Don't resize the old gen here. |
| |
| heap->resize_young_gen(size_policy->calculated_eden_size_in_bytes(), |
| size_policy->calculated_survivor_size_in_bytes()); |
| |
| log_debug(gc, ergo)("AdaptiveSizeStop: collection: %d ", heap->total_collections()); |
| } |
| |
| // Update the structure of the eden. With NUMA-eden CPU hotplugging or offlining can |
| // cause the change of the heap layout. Make sure eden is reshaped if that's the case. |
| // Also update() will case adaptive NUMA chunk resizing. |
| assert(young_gen->eden_space()->is_empty(), "eden space should be empty now"); |
| young_gen->eden_space()->update(); |
| |
| heap->gc_policy_counters()->update_counters(); |
| |
| heap->resize_all_tlabs(); |
| |
| assert(young_gen->to_space()->is_empty(), "to space should be empty now"); |
| } |
| |
| #if COMPILER2_OR_JVMCI |
| DerivedPointerTable::update_pointers(); |
| #endif |
| |
| // Re-verify object start arrays |
| if (VerifyObjectStartArray && |
| VerifyAfterGC) { |
| old_gen->verify_object_start_array(); |
| } |
| |
| // Verify all old -> young cards are now precise |
| if (VerifyRememberedSets) { |
| // Precise verification will give false positives. Until this is fixed, |
| // use imprecise verification. |
| // heap->card_table()->verify_all_young_refs_precise(); |
| heap->card_table()->verify_all_young_refs_imprecise(); |
| } |
| |
| if (log_is_enabled(Debug, gc, heap, exit)) { |
| accumulated_time()->stop(); |
| } |
| |
| heap->print_heap_change(pre_gc_values); |
| |
| // Track memory usage and detect low memory |
| MemoryService::track_memory_usage(); |
| heap->update_counters(); |
| } |
| |
| if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) { |
| Universe::verify("After GC"); |
| } |
| |
| heap->print_heap_after_gc(); |
| heap->trace_heap_after_gc(&_gc_tracer); |
| |
| AdaptiveSizePolicyOutput::print(size_policy, heap->total_collections()); |
| |
| _gc_timer.register_gc_end(); |
| |
| _gc_tracer.report_gc_end(_gc_timer.gc_end(), _gc_timer.time_partitions()); |
| |
| return !promotion_failure_occurred; |
| } |
| |
| void PSScavenge::clean_up_failed_promotion() { |
| PSPromotionManager::restore_preserved_marks(); |
| |
| // Reset the PromotionFailureALot counters. |
| NOT_PRODUCT(ParallelScavengeHeap::heap()->reset_promotion_should_fail();) |
| } |
| |
| bool PSScavenge::should_attempt_scavenge() { |
| ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); |
| PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters(); |
| |
| if (UsePerfData) { |
| counters->update_scavenge_skipped(not_skipped); |
| } |
| |
| PSYoungGen* young_gen = heap->young_gen(); |
| PSOldGen* old_gen = heap->old_gen(); |
| |
| // Do not attempt to promote unless to_space is empty |
| if (!young_gen->to_space()->is_empty()) { |
| if (UsePerfData) { |
| counters->update_scavenge_skipped(to_space_not_empty); |
| } |
| return false; |
| } |
| |
| // Test to see if the scavenge will likely fail. |
| PSAdaptiveSizePolicy* policy = heap->size_policy(); |
| |
| size_t avg_promoted = (size_t) policy->padded_average_promoted_in_bytes(); |
| size_t promotion_estimate = MIN2(avg_promoted, young_gen->used_in_bytes()); |
| // Total free size after possible old gen expansion |
| size_t free_in_old_gen = old_gen->max_gen_size() - old_gen->used_in_bytes(); |
| bool result = promotion_estimate < free_in_old_gen; |
| |
| log_trace(ergo)("%s scavenge: average_promoted " SIZE_FORMAT " padded_average_promoted " SIZE_FORMAT " free in old gen " SIZE_FORMAT, |
| result ? "Do" : "Skip", (size_t) policy->average_promoted_in_bytes(), |
| (size_t) policy->padded_average_promoted_in_bytes(), |
| free_in_old_gen); |
| if (young_gen->used_in_bytes() < (size_t) policy->padded_average_promoted_in_bytes()) { |
| log_trace(ergo)(" padded_promoted_average is greater than maximum promotion = " SIZE_FORMAT, young_gen->used_in_bytes()); |
| } |
| |
| if (!result) { |
| if (UsePerfData) { |
| counters->update_scavenge_skipped(promoted_too_large); |
| } |
| } |
| return result; |
| } |
| |
| // Adaptive size policy support. |
| void PSScavenge::set_young_generation_boundary(HeapWord* v) { |
| _young_generation_boundary = v; |
| if (UseCompressedOops) { |
| _young_generation_boundary_compressed = (uintptr_t)CompressedOops::encode(cast_to_oop(v)); |
| } |
| } |
| |
| void PSScavenge::initialize() { |
| // Arguments must have been parsed |
| |
| if (AlwaysTenure || NeverTenure) { |
| assert(MaxTenuringThreshold == 0 || MaxTenuringThreshold == markWord::max_age + 1, |
| "MaxTenuringThreshold should be 0 or markWord::max_age + 1, but is %d", (int) MaxTenuringThreshold); |
| _tenuring_threshold = MaxTenuringThreshold; |
| } else { |
| // We want to smooth out our startup times for the AdaptiveSizePolicy |
| _tenuring_threshold = (UseAdaptiveSizePolicy) ? InitialTenuringThreshold : |
| MaxTenuringThreshold; |
| } |
| |
| ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); |
| PSYoungGen* young_gen = heap->young_gen(); |
| PSOldGen* old_gen = heap->old_gen(); |
| |
| // Set boundary between young_gen and old_gen |
| assert(old_gen->reserved().end() <= young_gen->eden_space()->bottom(), |
| "old above young"); |
| set_young_generation_boundary(young_gen->eden_space()->bottom()); |
| |
| // Initialize ref handling object for scavenging. |
| _span_based_discoverer.set_span(young_gen->reserved()); |
| _ref_processor = |
| new ReferenceProcessor(&_span_based_discoverer, |
| ParallelGCThreads, // mt processing degree |
| ParallelGCThreads, // mt discovery degree |
| false, // concurrent_discovery |
| &_is_alive_closure); // header provides liveness info |
| |
| // Cache the cardtable |
| _card_table = heap->card_table(); |
| |
| _counters = new CollectorCounters("Parallel young collection pauses", 0); |
| } |
