diff -r 000000000000 -r f90c822e73f8 src/share/vm/gc_implementation/parallelScavenge/psOldGen.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/parallelScavenge/psOldGen.cpp Wed Apr 27 01:25:04 2016 +0800 @@ -0,0 +1,515 @@ +/* + * Copyright (c) 2001, 2014, 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 "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp" +#include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp" +#include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp" +#include "gc_implementation/parallelScavenge/psOldGen.hpp" +#include "gc_implementation/shared/spaceDecorator.hpp" +#include "memory/cardTableModRefBS.hpp" +#include "memory/gcLocker.inline.hpp" +#include "oops/oop.inline.hpp" +#include "runtime/java.hpp" + +PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC + +inline const char* PSOldGen::select_name() { + return UseParallelOldGC ? "ParOldGen" : "PSOldGen"; +} + +PSOldGen::PSOldGen(ReservedSpace rs, size_t alignment, + size_t initial_size, size_t min_size, size_t max_size, + const char* perf_data_name, int level): + _name(select_name()), _init_gen_size(initial_size), _min_gen_size(min_size), + _max_gen_size(max_size) +{ + initialize(rs, alignment, perf_data_name, level); +} + +PSOldGen::PSOldGen(size_t initial_size, + size_t min_size, size_t max_size, + const char* perf_data_name, int level): + _name(select_name()), _init_gen_size(initial_size), _min_gen_size(min_size), + _max_gen_size(max_size) +{} + +void PSOldGen::initialize(ReservedSpace rs, size_t alignment, + const char* perf_data_name, int level) { + initialize_virtual_space(rs, alignment); + initialize_work(perf_data_name, level); + + // The old gen can grow to gen_size_limit(). _reserve reflects only + // the current maximum that can be committed. + assert(_reserved.byte_size() <= gen_size_limit(), "Consistency check"); + + initialize_performance_counters(perf_data_name, level); +} + +void PSOldGen::initialize_virtual_space(ReservedSpace rs, size_t alignment) { + + _virtual_space = new PSVirtualSpace(rs, alignment); + if (!_virtual_space->expand_by(_init_gen_size)) { + vm_exit_during_initialization("Could not reserve enough space for " + "object heap"); + } +} + +void PSOldGen::initialize_work(const char* perf_data_name, int level) { + // + // Basic memory initialization + // + + MemRegion limit_reserved((HeapWord*)virtual_space()->low_boundary(), + heap_word_size(_max_gen_size)); + assert(limit_reserved.byte_size() == _max_gen_size, + "word vs bytes confusion"); + // + // Object start stuff + // + + start_array()->initialize(limit_reserved); + + _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(), + (HeapWord*)virtual_space()->high_boundary()); + + // + // Card table stuff + // + + MemRegion cmr((HeapWord*)virtual_space()->low(), + (HeapWord*)virtual_space()->high()); + if (ZapUnusedHeapArea) { + // Mangle newly committed space immediately rather than + // waiting for the initialization of the space even though + // mangling is related to spaces. Doing it here eliminates + // the need to carry along information that a complete mangling + // (bottom to end) needs to be done. + SpaceMangler::mangle_region(cmr); + } + + Universe::heap()->barrier_set()->resize_covered_region(cmr); + + CardTableModRefBS* _ct = (CardTableModRefBS*)Universe::heap()->barrier_set(); + assert (_ct->kind() == BarrierSet::CardTableModRef, "Sanity"); + + // Verify that the start and end of this generation is the start of a card. + // If this wasn't true, a single card could span more than one generation, + // which would cause problems when we commit/uncommit memory, and when we + // clear and dirty cards. + guarantee(_ct->is_card_aligned(_reserved.start()), "generation must be card aligned"); + if (_reserved.end() != Universe::heap()->reserved_region().end()) { + // Don't check at the very end of the heap as we'll assert that we're probing off + // the end if we try. + guarantee(_ct->is_card_aligned(_reserved.end()), "generation must be card aligned"); + } + + // + // ObjectSpace stuff + // + + _object_space = new MutableSpace(virtual_space()->alignment()); + + if (_object_space == NULL) + vm_exit_during_initialization("Could not allocate an old gen space"); + + object_space()->initialize(cmr, + SpaceDecorator::Clear, + SpaceDecorator::Mangle); + + _object_mark_sweep = new PSMarkSweepDecorator(_object_space, start_array(), MarkSweepDeadRatio); + + if (_object_mark_sweep == NULL) + vm_exit_during_initialization("Could not complete allocation of old generation"); + + // Update the start_array + start_array()->set_covered_region(cmr); +} + +void PSOldGen::initialize_performance_counters(const char* perf_data_name, int level) { + // Generation Counters, generation 'level', 1 subspace + _gen_counters = new PSGenerationCounters(perf_data_name, level, 1, + virtual_space()); + _space_counters = new SpaceCounters(perf_data_name, 0, + virtual_space()->reserved_size(), + _object_space, _gen_counters); +} + +// Assume that the generation has been allocated if its +// reserved size is not 0. +bool PSOldGen::is_allocated() { + return virtual_space()->reserved_size() != 0; +} + +void PSOldGen::precompact() { + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + + // Reset start array first. + start_array()->reset(); + + object_mark_sweep()->precompact(); + + // Now compact the young gen + heap->young_gen()->precompact(); +} + +void PSOldGen::adjust_pointers() { + object_mark_sweep()->adjust_pointers(); +} + +void PSOldGen::compact() { + object_mark_sweep()->compact(ZapUnusedHeapArea); +} + +size_t PSOldGen::contiguous_available() const { + return object_space()->free_in_bytes() + virtual_space()->uncommitted_size(); +} + +// Allocation. We report all successful allocations to the size policy +// Note that the perm gen does not use this method, and should not! +HeapWord* PSOldGen::allocate(size_t word_size) { + assert_locked_or_safepoint(Heap_lock); + HeapWord* res = allocate_noexpand(word_size); + + if (res == NULL) { + res = expand_and_allocate(word_size); + } + + // Allocations in the old generation need to be reported + if (res != NULL) { + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + heap->size_policy()->tenured_allocation(word_size); + } + + return res; +} + +HeapWord* PSOldGen::expand_and_allocate(size_t word_size) { + expand(word_size*HeapWordSize); + if (GCExpandToAllocateDelayMillis > 0) { + os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false); + } + return allocate_noexpand(word_size); +} + +HeapWord* PSOldGen::expand_and_cas_allocate(size_t word_size) { + expand(word_size*HeapWordSize); + if (GCExpandToAllocateDelayMillis > 0) { + os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false); + } + return cas_allocate_noexpand(word_size); +} + +void PSOldGen::expand(size_t bytes) { + if (bytes == 0) { + return; + } + MutexLocker x(ExpandHeap_lock); + const size_t alignment = virtual_space()->alignment(); + size_t aligned_bytes = align_size_up(bytes, alignment); + size_t aligned_expand_bytes = align_size_up(MinHeapDeltaBytes, alignment); + + if (UseNUMA) { + // With NUMA we use round-robin page allocation for the old gen. Expand by at least + // providing a page per lgroup. Alignment is larger or equal to the page size. + aligned_expand_bytes = MAX2(aligned_expand_bytes, alignment * os::numa_get_groups_num()); + } + if (aligned_bytes == 0){ + // The alignment caused the number of bytes to wrap. An expand_by(0) will + // return true with the implication that and expansion was done when it + // was not. A call to expand implies a best effort to expand by "bytes" + // but not a guarantee. Align down to give a best effort. This is likely + // the most that the generation can expand since it has some capacity to + // start with. + aligned_bytes = align_size_down(bytes, alignment); + } + + bool success = false; + if (aligned_expand_bytes > aligned_bytes) { + success = expand_by(aligned_expand_bytes); + } + if (!success) { + success = expand_by(aligned_bytes); + } + if (!success) { + success = expand_to_reserved(); + } + + if (PrintGC && Verbose) { + if (success && GC_locker::is_active_and_needs_gc()) { + gclog_or_tty->print_cr("Garbage collection disabled, expanded heap instead"); + } + } +} + +bool PSOldGen::expand_by(size_t bytes) { + assert_lock_strong(ExpandHeap_lock); + assert_locked_or_safepoint(Heap_lock); + if (bytes == 0) { + return true; // That's what virtual_space()->expand_by(0) would return + } + bool result = virtual_space()->expand_by(bytes); + if (result) { + if (ZapUnusedHeapArea) { + // We need to mangle the newly expanded area. The memregion spans + // end -> new_end, we assume that top -> end is already mangled. + // Do the mangling before post_resize() is called because + // the space is available for allocation after post_resize(); + HeapWord* const virtual_space_high = (HeapWord*) virtual_space()->high(); + assert(object_space()->end() < virtual_space_high, + "Should be true before post_resize()"); + MemRegion mangle_region(object_space()->end(), virtual_space_high); + // Note that the object space has not yet been updated to + // coincede with the new underlying virtual space. + SpaceMangler::mangle_region(mangle_region); + } + post_resize(); + if (UsePerfData) { + _space_counters->update_capacity(); + _gen_counters->update_all(); + } + } + + if (result && Verbose && PrintGC) { + size_t new_mem_size = virtual_space()->committed_size(); + size_t old_mem_size = new_mem_size - bytes; + gclog_or_tty->print_cr("Expanding %s from " SIZE_FORMAT "K by " + SIZE_FORMAT "K to " + SIZE_FORMAT "K", + name(), old_mem_size/K, bytes/K, new_mem_size/K); + } + + return result; +} + +bool PSOldGen::expand_to_reserved() { + assert_lock_strong(ExpandHeap_lock); + assert_locked_or_safepoint(Heap_lock); + + bool result = true; + const size_t remaining_bytes = virtual_space()->uncommitted_size(); + if (remaining_bytes > 0) { + result = expand_by(remaining_bytes); + DEBUG_ONLY(if (!result) warning("grow to reserve failed")); + } + return result; +} + +void PSOldGen::shrink(size_t bytes) { + assert_lock_strong(ExpandHeap_lock); + assert_locked_or_safepoint(Heap_lock); + + size_t size = align_size_down(bytes, virtual_space()->alignment()); + if (size > 0) { + assert_lock_strong(ExpandHeap_lock); + virtual_space()->shrink_by(bytes); + post_resize(); + + if (Verbose && PrintGC) { + size_t new_mem_size = virtual_space()->committed_size(); + size_t old_mem_size = new_mem_size + bytes; + gclog_or_tty->print_cr("Shrinking %s from " SIZE_FORMAT "K by " + SIZE_FORMAT "K to " + SIZE_FORMAT "K", + name(), old_mem_size/K, bytes/K, new_mem_size/K); + } + } +} + +void PSOldGen::resize(size_t desired_free_space) { + const size_t alignment = virtual_space()->alignment(); + const size_t size_before = virtual_space()->committed_size(); + size_t new_size = used_in_bytes() + desired_free_space; + if (new_size < used_in_bytes()) { + // Overflowed the addition. + new_size = gen_size_limit(); + } + // Adjust according to our min and max + new_size = MAX2(MIN2(new_size, gen_size_limit()), min_gen_size()); + + assert(gen_size_limit() >= reserved().byte_size(), "max new size problem?"); + new_size = align_size_up(new_size, alignment); + + const size_t current_size = capacity_in_bytes(); + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("AdaptiveSizePolicy::old generation size: " + "desired free: " SIZE_FORMAT " used: " SIZE_FORMAT + " new size: " SIZE_FORMAT " current size " SIZE_FORMAT + " gen limits: " SIZE_FORMAT " / " SIZE_FORMAT, + desired_free_space, used_in_bytes(), new_size, current_size, + gen_size_limit(), min_gen_size()); + } + + if (new_size == current_size) { + // No change requested + return; + } + if (new_size > current_size) { + size_t change_bytes = new_size - current_size; + expand(change_bytes); + } else { + size_t change_bytes = current_size - new_size; + // shrink doesn't grab this lock, expand does. Is that right? + MutexLocker x(ExpandHeap_lock); + shrink(change_bytes); + } + + if (PrintAdaptiveSizePolicy) { + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + gclog_or_tty->print_cr("AdaptiveSizePolicy::old generation size: " + "collection: %d " + "(" SIZE_FORMAT ") -> (" SIZE_FORMAT ") ", + heap->total_collections(), + size_before, virtual_space()->committed_size()); + } +} + +// NOTE! We need to be careful about resizing. During a GC, multiple +// allocators may be active during heap expansion. If we allow the +// heap resizing to become visible before we have correctly resized +// all heap related data structures, we may cause program failures. +void PSOldGen::post_resize() { + // First construct a memregion representing the new size + MemRegion new_memregion((HeapWord*)virtual_space()->low(), + (HeapWord*)virtual_space()->high()); + size_t new_word_size = new_memregion.word_size(); + + start_array()->set_covered_region(new_memregion); + Universe::heap()->barrier_set()->resize_covered_region(new_memregion); + + // ALWAYS do this last!! + object_space()->initialize(new_memregion, + SpaceDecorator::DontClear, + SpaceDecorator::DontMangle); + + assert(new_word_size == heap_word_size(object_space()->capacity_in_bytes()), + "Sanity"); +} + +size_t PSOldGen::gen_size_limit() { + return _max_gen_size; +} + +void PSOldGen::reset_after_change() { + ShouldNotReachHere(); + return; +} + +size_t PSOldGen::available_for_expansion() { + ShouldNotReachHere(); + return 0; +} + +size_t PSOldGen::available_for_contraction() { + ShouldNotReachHere(); + return 0; +} + +void PSOldGen::print() const { print_on(tty);} +void PSOldGen::print_on(outputStream* st) const { + st->print(" %-15s", name()); + if (PrintGCDetails && Verbose) { + st->print(" total " SIZE_FORMAT ", used " SIZE_FORMAT, + capacity_in_bytes(), used_in_bytes()); + } else { + st->print(" total " SIZE_FORMAT "K, used " SIZE_FORMAT "K", + capacity_in_bytes()/K, used_in_bytes()/K); + } + st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ")", + virtual_space()->low_boundary(), + virtual_space()->high(), + virtual_space()->high_boundary()); + + st->print(" object"); object_space()->print_on(st); +} + +void PSOldGen::print_used_change(size_t prev_used) const { + gclog_or_tty->print(" [%s:", name()); + gclog_or_tty->print(" " SIZE_FORMAT "K" + "->" SIZE_FORMAT "K" + "(" SIZE_FORMAT "K)", + prev_used / K, used_in_bytes() / K, + capacity_in_bytes() / K); + gclog_or_tty->print("]"); +} + +void PSOldGen::update_counters() { + if (UsePerfData) { + _space_counters->update_all(); + _gen_counters->update_all(); + } +} + +#ifndef PRODUCT + +void PSOldGen::space_invariants() { + assert(object_space()->end() == (HeapWord*) virtual_space()->high(), + "Space invariant"); + assert(object_space()->bottom() == (HeapWord*) virtual_space()->low(), + "Space invariant"); + assert(virtual_space()->low_boundary() <= virtual_space()->low(), + "Space invariant"); + assert(virtual_space()->high_boundary() >= virtual_space()->high(), + "Space invariant"); + assert(virtual_space()->low_boundary() == (char*) _reserved.start(), + "Space invariant"); + assert(virtual_space()->high_boundary() == (char*) _reserved.end(), + "Space invariant"); + assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(), + "Space invariant"); +} +#endif + +void PSOldGen::verify() { + object_space()->verify(); +} +class VerifyObjectStartArrayClosure : public ObjectClosure { + PSOldGen* _gen; + ObjectStartArray* _start_array; + + public: + VerifyObjectStartArrayClosure(PSOldGen* gen, ObjectStartArray* start_array) : + _gen(gen), _start_array(start_array) { } + + virtual void do_object(oop obj) { + HeapWord* test_addr = (HeapWord*)obj + 1; + guarantee(_start_array->object_start(test_addr) == (HeapWord*)obj, "ObjectStartArray cannot find start of object"); + guarantee(_start_array->is_block_allocated((HeapWord*)obj), "ObjectStartArray missing block allocation"); + } +}; + +void PSOldGen::verify_object_start_array() { + VerifyObjectStartArrayClosure check( this, &_start_array ); + object_iterate(&check); +} + +#ifndef PRODUCT +void PSOldGen::record_spaces_top() { + assert(ZapUnusedHeapArea, "Not mangling unused space"); + object_space()->set_top_for_allocations(); +} +#endif