| /* |
| * Copyright (c) 2013, 2019, Red Hat, Inc. All rights reserved. |
| * |
| * 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 "memory/allocation.hpp" |
| #include "gc/shenandoah/shenandoahHeapRegionSet.inline.hpp" |
| #include "gc/shenandoah/shenandoahHeap.inline.hpp" |
| #include "gc/shenandoah/shenandoahHeapRegion.hpp" |
| #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp" |
| #include "gc/shenandoah/shenandoahTraversalGC.hpp" |
| #include "gc/shared/space.inline.hpp" |
| #include "jfr/jfrEvents.hpp" |
| #include "memory/iterator.inline.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "memory/universe.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/java.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/os.hpp" |
| #include "runtime/safepoint.hpp" |
| |
| size_t ShenandoahHeapRegion::RegionCount = 0; |
| size_t ShenandoahHeapRegion::RegionSizeBytes = 0; |
| size_t ShenandoahHeapRegion::RegionSizeWords = 0; |
| size_t ShenandoahHeapRegion::RegionSizeBytesShift = 0; |
| size_t ShenandoahHeapRegion::RegionSizeWordsShift = 0; |
| size_t ShenandoahHeapRegion::RegionSizeBytesMask = 0; |
| size_t ShenandoahHeapRegion::RegionSizeWordsMask = 0; |
| size_t ShenandoahHeapRegion::HumongousThresholdBytes = 0; |
| size_t ShenandoahHeapRegion::HumongousThresholdWords = 0; |
| size_t ShenandoahHeapRegion::MaxTLABSizeBytes = 0; |
| size_t ShenandoahHeapRegion::MaxTLABSizeWords = 0; |
| |
| ShenandoahHeapRegion::PaddedAllocSeqNum ShenandoahHeapRegion::_alloc_seq_num; |
| |
| ShenandoahHeapRegion::ShenandoahHeapRegion(ShenandoahHeap* heap, HeapWord* start, |
| size_t size_words, size_t index, bool committed) : |
| _heap(heap), |
| _reserved(MemRegion(start, size_words)), |
| _region_number(index), |
| _new_top(NULL), |
| _critical_pins(0), |
| _empty_time(os::elapsedTime()), |
| _state(committed ? _empty_committed : _empty_uncommitted), |
| _tlab_allocs(0), |
| _gclab_allocs(0), |
| _shared_allocs(0), |
| _seqnum_first_alloc_mutator(0), |
| _seqnum_first_alloc_gc(0), |
| _seqnum_last_alloc_mutator(0), |
| _seqnum_last_alloc_gc(0), |
| _live_data(0) { |
| |
| ContiguousSpace::initialize(_reserved, true, committed); |
| } |
| |
| size_t ShenandoahHeapRegion::region_number() const { |
| return _region_number; |
| } |
| |
| void ShenandoahHeapRegion::report_illegal_transition(const char *method) { |
| ResourceMark rm; |
| stringStream ss; |
| ss.print("Illegal region state transition from \"%s\", at %s\n ", region_state_to_string(_state), method); |
| print_on(&ss); |
| fatal("%s", ss.as_string()); |
| } |
| |
| void ShenandoahHeapRegion::make_regular_allocation() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| |
| switch (_state) { |
| case _empty_uncommitted: |
| do_commit(); |
| case _empty_committed: |
| set_state(_regular); |
| case _regular: |
| case _pinned: |
| return; |
| default: |
| report_illegal_transition("regular allocation"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_regular_bypass() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| assert (_heap->is_full_gc_in_progress() || _heap->is_degenerated_gc_in_progress(), |
| "only for full or degen GC"); |
| |
| switch (_state) { |
| case _empty_uncommitted: |
| do_commit(); |
| case _empty_committed: |
| case _cset: |
| case _humongous_start: |
| case _humongous_cont: |
| set_state(_regular); |
| return; |
| case _pinned_cset: |
| set_state(_pinned); |
| return; |
| case _regular: |
| case _pinned: |
| return; |
| default: |
| report_illegal_transition("regular bypass"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_humongous_start() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| switch (_state) { |
| case _empty_uncommitted: |
| do_commit(); |
| case _empty_committed: |
| set_state(_humongous_start); |
| return; |
| default: |
| report_illegal_transition("humongous start allocation"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_humongous_start_bypass() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| assert (_heap->is_full_gc_in_progress(), "only for full GC"); |
| |
| switch (_state) { |
| case _empty_committed: |
| case _regular: |
| case _humongous_start: |
| case _humongous_cont: |
| set_state(_humongous_start); |
| return; |
| default: |
| report_illegal_transition("humongous start bypass"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_humongous_cont() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| switch (_state) { |
| case _empty_uncommitted: |
| do_commit(); |
| case _empty_committed: |
| set_state(_humongous_cont); |
| return; |
| default: |
| report_illegal_transition("humongous continuation allocation"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_humongous_cont_bypass() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| assert (_heap->is_full_gc_in_progress(), "only for full GC"); |
| |
| switch (_state) { |
| case _empty_committed: |
| case _regular: |
| case _humongous_start: |
| case _humongous_cont: |
| set_state(_humongous_cont); |
| return; |
| default: |
| report_illegal_transition("humongous continuation bypass"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_pinned() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| switch (_state) { |
| case _regular: |
| assert (_critical_pins == 0, "sanity"); |
| set_state(_pinned); |
| case _pinned_cset: |
| case _pinned: |
| _critical_pins++; |
| return; |
| case _humongous_start: |
| assert (_critical_pins == 0, "sanity"); |
| set_state(_pinned_humongous_start); |
| case _pinned_humongous_start: |
| _critical_pins++; |
| return; |
| case _cset: |
| guarantee(_heap->cancelled_gc(), "only valid when evac has been cancelled"); |
| assert (_critical_pins == 0, "sanity"); |
| _state = _pinned_cset; |
| _critical_pins++; |
| return; |
| default: |
| report_illegal_transition("pinning"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_unpinned() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| switch (_state) { |
| case _pinned: |
| assert (_critical_pins > 0, "sanity"); |
| _critical_pins--; |
| if (_critical_pins == 0) { |
| set_state(_regular); |
| } |
| return; |
| case _regular: |
| case _humongous_start: |
| assert (_critical_pins == 0, "sanity"); |
| return; |
| case _pinned_cset: |
| guarantee(_heap->cancelled_gc(), "only valid when evac has been cancelled"); |
| assert (_critical_pins > 0, "sanity"); |
| _critical_pins--; |
| if (_critical_pins == 0) { |
| set_state(_cset); |
| } |
| return; |
| case _pinned_humongous_start: |
| assert (_critical_pins > 0, "sanity"); |
| _critical_pins--; |
| if (_critical_pins == 0) { |
| set_state(_humongous_start); |
| } |
| return; |
| default: |
| report_illegal_transition("unpinning"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_cset() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| switch (_state) { |
| case _regular: |
| set_state(_cset); |
| case _cset: |
| return; |
| default: |
| report_illegal_transition("cset"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_trash() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| switch (_state) { |
| case _cset: |
| // Reclaiming cset regions |
| case _humongous_start: |
| case _humongous_cont: |
| // Reclaiming humongous regions |
| case _regular: |
| // Immediate region reclaim |
| set_state(_trash); |
| return; |
| default: |
| report_illegal_transition("trashing"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_trash_immediate() { |
| make_trash(); |
| |
| // On this path, we know there are no marked objects in the region, |
| // tell marking context about it to bypass bitmap resets. |
| _heap->complete_marking_context()->reset_top_bitmap(this); |
| } |
| |
| void ShenandoahHeapRegion::make_empty() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| switch (_state) { |
| case _trash: |
| set_state(_empty_committed); |
| _empty_time = os::elapsedTime(); |
| return; |
| default: |
| report_illegal_transition("emptying"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_uncommitted() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| switch (_state) { |
| case _empty_committed: |
| do_uncommit(); |
| set_state(_empty_uncommitted); |
| return; |
| default: |
| report_illegal_transition("uncommiting"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::make_committed_bypass() { |
| _heap->assert_heaplock_owned_by_current_thread(); |
| assert (_heap->is_full_gc_in_progress(), "only for full GC"); |
| |
| switch (_state) { |
| case _empty_uncommitted: |
| do_commit(); |
| set_state(_empty_committed); |
| return; |
| default: |
| report_illegal_transition("commit bypass"); |
| } |
| } |
| |
| void ShenandoahHeapRegion::clear_live_data() { |
| OrderAccess::release_store_fence<size_t>(&_live_data, 0); |
| } |
| |
| void ShenandoahHeapRegion::reset_alloc_metadata() { |
| _tlab_allocs = 0; |
| _gclab_allocs = 0; |
| _shared_allocs = 0; |
| _seqnum_first_alloc_mutator = 0; |
| _seqnum_last_alloc_mutator = 0; |
| _seqnum_first_alloc_gc = 0; |
| _seqnum_last_alloc_gc = 0; |
| } |
| |
| void ShenandoahHeapRegion::reset_alloc_metadata_to_shared() { |
| if (used() > 0) { |
| _tlab_allocs = 0; |
| _gclab_allocs = 0; |
| _shared_allocs = used() >> LogHeapWordSize; |
| uint64_t next = _alloc_seq_num.value++; |
| _seqnum_first_alloc_mutator = next; |
| _seqnum_last_alloc_mutator = next; |
| _seqnum_first_alloc_gc = 0; |
| _seqnum_last_alloc_gc = 0; |
| } else { |
| reset_alloc_metadata(); |
| } |
| } |
| |
| size_t ShenandoahHeapRegion::get_shared_allocs() const { |
| return _shared_allocs * HeapWordSize; |
| } |
| |
| size_t ShenandoahHeapRegion::get_tlab_allocs() const { |
| return _tlab_allocs * HeapWordSize; |
| } |
| |
| size_t ShenandoahHeapRegion::get_gclab_allocs() const { |
| return _gclab_allocs * HeapWordSize; |
| } |
| |
| void ShenandoahHeapRegion::set_live_data(size_t s) { |
| assert(Thread::current()->is_VM_thread(), "by VM thread"); |
| _live_data = (s >> LogHeapWordSize); |
| } |
| |
| size_t ShenandoahHeapRegion::get_live_data_words() const { |
| return OrderAccess::load_acquire(&_live_data); |
| } |
| |
| size_t ShenandoahHeapRegion::get_live_data_bytes() const { |
| return get_live_data_words() * HeapWordSize; |
| } |
| |
| bool ShenandoahHeapRegion::has_live() const { |
| return get_live_data_words() != 0; |
| } |
| |
| size_t ShenandoahHeapRegion::garbage() const { |
| assert(used() >= get_live_data_bytes(), "Live Data must be a subset of used() live: " SIZE_FORMAT " used: " SIZE_FORMAT, |
| get_live_data_bytes(), used()); |
| |
| size_t result = used() - get_live_data_bytes(); |
| return result; |
| } |
| |
| void ShenandoahHeapRegion::print_on(outputStream* st) const { |
| st->print("|"); |
| st->print(SIZE_FORMAT_W(5), this->_region_number); |
| |
| switch (_state) { |
| case _empty_uncommitted: |
| st->print("|EU "); |
| break; |
| case _empty_committed: |
| st->print("|EC "); |
| break; |
| case _regular: |
| st->print("|R "); |
| break; |
| case _humongous_start: |
| st->print("|H "); |
| break; |
| case _pinned_humongous_start: |
| st->print("|HP "); |
| break; |
| case _humongous_cont: |
| st->print("|HC "); |
| break; |
| case _cset: |
| st->print("|CS "); |
| break; |
| case _trash: |
| st->print("|T "); |
| break; |
| case _pinned: |
| st->print("|P "); |
| break; |
| case _pinned_cset: |
| st->print("|CSP"); |
| break; |
| default: |
| ShouldNotReachHere(); |
| } |
| st->print("|BTE " INTPTR_FORMAT_W(12) ", " INTPTR_FORMAT_W(12) ", " INTPTR_FORMAT_W(12), |
| p2i(bottom()), p2i(top()), p2i(end())); |
| st->print("|TAMS " INTPTR_FORMAT_W(12), |
| p2i(_heap->marking_context()->top_at_mark_start(const_cast<ShenandoahHeapRegion*>(this)))); |
| st->print("|U " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(used()), proper_unit_for_byte_size(used())); |
| st->print("|T " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(get_tlab_allocs()), proper_unit_for_byte_size(get_tlab_allocs())); |
| st->print("|G " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(get_gclab_allocs()), proper_unit_for_byte_size(get_gclab_allocs())); |
| st->print("|S " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(get_shared_allocs()), proper_unit_for_byte_size(get_shared_allocs())); |
| st->print("|L " SIZE_FORMAT_W(5) "%1s", byte_size_in_proper_unit(get_live_data_bytes()), proper_unit_for_byte_size(get_live_data_bytes())); |
| st->print("|CP " SIZE_FORMAT_W(3), _critical_pins); |
| st->print("|SN " UINT64_FORMAT_X_W(12) ", " UINT64_FORMAT_X_W(8) ", " UINT64_FORMAT_X_W(8) ", " UINT64_FORMAT_X_W(8), |
| seqnum_first_alloc_mutator(), seqnum_last_alloc_mutator(), |
| seqnum_first_alloc_gc(), seqnum_last_alloc_gc()); |
| st->cr(); |
| } |
| |
| void ShenandoahHeapRegion::oop_iterate(OopIterateClosure* blk) { |
| if (!is_active()) return; |
| if (is_humongous()) { |
| oop_iterate_humongous(blk); |
| } else { |
| oop_iterate_objects(blk); |
| } |
| } |
| |
| void ShenandoahHeapRegion::oop_iterate_objects(OopIterateClosure* blk) { |
| assert(! is_humongous(), "no humongous region here"); |
| HeapWord* obj_addr = bottom(); |
| HeapWord* t = top(); |
| // Could call objects iterate, but this is easier. |
| while (obj_addr < t) { |
| oop obj = oop(obj_addr); |
| obj_addr += obj->oop_iterate_size(blk); |
| } |
| } |
| |
| void ShenandoahHeapRegion::oop_iterate_humongous(OopIterateClosure* blk) { |
| assert(is_humongous(), "only humongous region here"); |
| // Find head. |
| ShenandoahHeapRegion* r = humongous_start_region(); |
| assert(r->is_humongous_start(), "need humongous head here"); |
| oop obj = oop(r->bottom()); |
| obj->oop_iterate(blk, MemRegion(bottom(), top())); |
| } |
| |
| ShenandoahHeapRegion* ShenandoahHeapRegion::humongous_start_region() const { |
| assert(is_humongous(), "Must be a part of the humongous region"); |
| size_t reg_num = region_number(); |
| ShenandoahHeapRegion* r = const_cast<ShenandoahHeapRegion*>(this); |
| while (!r->is_humongous_start()) { |
| assert(reg_num > 0, "Sanity"); |
| reg_num --; |
| r = _heap->get_region(reg_num); |
| assert(r->is_humongous(), "Must be a part of the humongous region"); |
| } |
| assert(r->is_humongous_start(), "Must be"); |
| return r; |
| } |
| |
| void ShenandoahHeapRegion::recycle() { |
| ContiguousSpace::clear(false); |
| if (ZapUnusedHeapArea) { |
| ContiguousSpace::mangle_unused_area_complete(); |
| } |
| clear_live_data(); |
| |
| reset_alloc_metadata(); |
| |
| _heap->marking_context()->reset_top_at_mark_start(this); |
| |
| make_empty(); |
| } |
| |
| HeapWord* ShenandoahHeapRegion::block_start_const(const void* p) const { |
| assert(MemRegion(bottom(), end()).contains(p), |
| "p (" PTR_FORMAT ") not in space [" PTR_FORMAT ", " PTR_FORMAT ")", |
| p2i(p), p2i(bottom()), p2i(end())); |
| if (p >= top()) { |
| return top(); |
| } else { |
| HeapWord* last = bottom(); |
| HeapWord* cur = last; |
| while (cur <= p) { |
| last = cur; |
| cur += oop(cur)->size(); |
| } |
| shenandoah_assert_correct(NULL, oop(last)); |
| return last; |
| } |
| } |
| |
| void ShenandoahHeapRegion::setup_sizes(size_t max_heap_size) { |
| // Absolute minimums we should not ever break. |
| static const size_t MIN_REGION_SIZE = 256*K; |
| |
| if (FLAG_IS_DEFAULT(ShenandoahMinRegionSize)) { |
| FLAG_SET_DEFAULT(ShenandoahMinRegionSize, MIN_REGION_SIZE); |
| } |
| |
| size_t region_size; |
| if (FLAG_IS_DEFAULT(ShenandoahHeapRegionSize)) { |
| if (ShenandoahMinRegionSize > max_heap_size / MIN_NUM_REGIONS) { |
| err_msg message("Max heap size (" SIZE_FORMAT "K) is too low to afford the minimum number " |
| "of regions (" SIZE_FORMAT ") of minimum region size (" SIZE_FORMAT "K).", |
| max_heap_size/K, MIN_NUM_REGIONS, ShenandoahMinRegionSize/K); |
| vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize option", message); |
| } |
| if (ShenandoahMinRegionSize < MIN_REGION_SIZE) { |
| err_msg message("" SIZE_FORMAT "K should not be lower than minimum region size (" SIZE_FORMAT "K).", |
| ShenandoahMinRegionSize/K, MIN_REGION_SIZE/K); |
| vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize option", message); |
| } |
| if (ShenandoahMinRegionSize < MinTLABSize) { |
| err_msg message("" SIZE_FORMAT "K should not be lower than TLAB size size (" SIZE_FORMAT "K).", |
| ShenandoahMinRegionSize/K, MinTLABSize/K); |
| vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize option", message); |
| } |
| if (ShenandoahMaxRegionSize < MIN_REGION_SIZE) { |
| err_msg message("" SIZE_FORMAT "K should not be lower than min region size (" SIZE_FORMAT "K).", |
| ShenandoahMaxRegionSize/K, MIN_REGION_SIZE/K); |
| vm_exit_during_initialization("Invalid -XX:ShenandoahMaxRegionSize option", message); |
| } |
| if (ShenandoahMinRegionSize > ShenandoahMaxRegionSize) { |
| err_msg message("Minimum (" SIZE_FORMAT "K) should be larger than maximum (" SIZE_FORMAT "K).", |
| ShenandoahMinRegionSize/K, ShenandoahMaxRegionSize/K); |
| vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize or -XX:ShenandoahMaxRegionSize", message); |
| } |
| |
| // We rapidly expand to max_heap_size in most scenarios, so that is the measure |
| // for usual heap sizes. Do not depend on initial_heap_size here. |
| region_size = max_heap_size / ShenandoahTargetNumRegions; |
| |
| // Now make sure that we don't go over or under our limits. |
| region_size = MAX2(ShenandoahMinRegionSize, region_size); |
| region_size = MIN2(ShenandoahMaxRegionSize, region_size); |
| |
| } else { |
| if (ShenandoahHeapRegionSize > max_heap_size / MIN_NUM_REGIONS) { |
| err_msg message("Max heap size (" SIZE_FORMAT "K) is too low to afford the minimum number " |
| "of regions (" SIZE_FORMAT ") of requested size (" SIZE_FORMAT "K).", |
| max_heap_size/K, MIN_NUM_REGIONS, ShenandoahHeapRegionSize/K); |
| vm_exit_during_initialization("Invalid -XX:ShenandoahHeapRegionSize option", message); |
| } |
| if (ShenandoahHeapRegionSize < ShenandoahMinRegionSize) { |
| err_msg message("Heap region size (" SIZE_FORMAT "K) should be larger than min region size (" SIZE_FORMAT "K).", |
| ShenandoahHeapRegionSize/K, ShenandoahMinRegionSize/K); |
| vm_exit_during_initialization("Invalid -XX:ShenandoahHeapRegionSize option", message); |
| } |
| if (ShenandoahHeapRegionSize > ShenandoahMaxRegionSize) { |
| err_msg message("Heap region size (" SIZE_FORMAT "K) should be lower than max region size (" SIZE_FORMAT "K).", |
| ShenandoahHeapRegionSize/K, ShenandoahMaxRegionSize/K); |
| vm_exit_during_initialization("Invalid -XX:ShenandoahHeapRegionSize option", message); |
| } |
| region_size = ShenandoahHeapRegionSize; |
| } |
| |
| // Make sure region size is at least one large page, if enabled. |
| // Otherwise, uncommitting one region may falsely uncommit the adjacent |
| // regions too. |
| // Also see shenandoahArguments.cpp, where it handles UseLargePages. |
| if (UseLargePages && ShenandoahUncommit) { |
| region_size = MAX2(region_size, os::large_page_size()); |
| } |
| |
| int region_size_log = log2_long((jlong) region_size); |
| // Recalculate the region size to make sure it's a power of |
| // 2. This means that region_size is the largest power of 2 that's |
| // <= what we've calculated so far. |
| region_size = size_t(1) << region_size_log; |
| |
| // Now, set up the globals. |
| guarantee(RegionSizeBytesShift == 0, "we should only set it once"); |
| RegionSizeBytesShift = (size_t)region_size_log; |
| |
| guarantee(RegionSizeWordsShift == 0, "we should only set it once"); |
| RegionSizeWordsShift = RegionSizeBytesShift - LogHeapWordSize; |
| |
| guarantee(RegionSizeBytes == 0, "we should only set it once"); |
| RegionSizeBytes = region_size; |
| RegionSizeWords = RegionSizeBytes >> LogHeapWordSize; |
| assert (RegionSizeWords*HeapWordSize == RegionSizeBytes, "sanity"); |
| |
| guarantee(RegionSizeWordsMask == 0, "we should only set it once"); |
| RegionSizeWordsMask = RegionSizeWords - 1; |
| |
| guarantee(RegionSizeBytesMask == 0, "we should only set it once"); |
| RegionSizeBytesMask = RegionSizeBytes - 1; |
| |
| guarantee(RegionCount == 0, "we should only set it once"); |
| RegionCount = max_heap_size / RegionSizeBytes; |
| guarantee(RegionCount >= MIN_NUM_REGIONS, "Should have at least minimum regions"); |
| |
| guarantee(HumongousThresholdWords == 0, "we should only set it once"); |
| HumongousThresholdWords = RegionSizeWords * ShenandoahHumongousThreshold / 100; |
| HumongousThresholdWords = align_down(HumongousThresholdWords, MinObjAlignment); |
| assert (HumongousThresholdWords <= RegionSizeWords, "sanity"); |
| |
| guarantee(HumongousThresholdBytes == 0, "we should only set it once"); |
| HumongousThresholdBytes = HumongousThresholdWords * HeapWordSize; |
| assert (HumongousThresholdBytes <= RegionSizeBytes, "sanity"); |
| |
| // The rationale for trimming the TLAB sizes has to do with the raciness in |
| // TLAB allocation machinery. It may happen that TLAB sizing policy polls Shenandoah |
| // about next free size, gets the answer for region #N, goes away for a while, then |
| // tries to allocate in region #N, and fail because some other thread have claimed part |
| // of the region #N, and then the freeset allocation code has to retire the region #N, |
| // before moving the allocation to region #N+1. |
| // |
| // The worst case realizes when "answer" is "region size", which means it could |
| // prematurely retire an entire region. Having smaller TLABs does not fix that |
| // completely, but reduces the probability of too wasteful region retirement. |
| // With current divisor, we will waste no more than 1/8 of region size in the worst |
| // case. This also has a secondary effect on collection set selection: even under |
| // the race, the regions would be at least 7/8 used, which allows relying on |
| // "used" - "live" for cset selection. Otherwise, we can get the fragmented region |
| // below the garbage threshold that would never be considered for collection. |
| // |
| // The whole thing is mitigated if Elastic TLABs are enabled. |
| // |
| guarantee(MaxTLABSizeWords == 0, "we should only set it once"); |
| MaxTLABSizeWords = MIN2(ShenandoahElasticTLAB ? RegionSizeWords : (RegionSizeWords / 8), HumongousThresholdWords); |
| MaxTLABSizeWords = align_down(MaxTLABSizeWords, MinObjAlignment); |
| |
| guarantee(MaxTLABSizeBytes == 0, "we should only set it once"); |
| MaxTLABSizeBytes = MaxTLABSizeWords * HeapWordSize; |
| assert (MaxTLABSizeBytes > MinTLABSize, "should be larger"); |
| |
| log_info(gc, init)("Regions: " SIZE_FORMAT " x " SIZE_FORMAT "%s", |
| RegionCount, byte_size_in_proper_unit(RegionSizeBytes), proper_unit_for_byte_size(RegionSizeBytes)); |
| log_info(gc, init)("Humongous object threshold: " SIZE_FORMAT "%s", |
| byte_size_in_proper_unit(HumongousThresholdBytes), proper_unit_for_byte_size(HumongousThresholdBytes)); |
| log_info(gc, init)("Max TLAB size: " SIZE_FORMAT "%s", |
| byte_size_in_proper_unit(MaxTLABSizeBytes), proper_unit_for_byte_size(MaxTLABSizeBytes)); |
| } |
| |
| void ShenandoahHeapRegion::do_commit() { |
| if (!_heap->is_heap_region_special() && !os::commit_memory((char *) _reserved.start(), _reserved.byte_size(), false)) { |
| report_java_out_of_memory("Unable to commit region"); |
| } |
| if (!_heap->commit_bitmap_slice(this)) { |
| report_java_out_of_memory("Unable to commit bitmaps for region"); |
| } |
| _heap->increase_committed(ShenandoahHeapRegion::region_size_bytes()); |
| } |
| |
| void ShenandoahHeapRegion::do_uncommit() { |
| if (!_heap->is_heap_region_special() && !os::uncommit_memory((char *) _reserved.start(), _reserved.byte_size())) { |
| report_java_out_of_memory("Unable to uncommit region"); |
| } |
| if (!_heap->uncommit_bitmap_slice(this)) { |
| report_java_out_of_memory("Unable to uncommit bitmaps for region"); |
| } |
| _heap->decrease_committed(ShenandoahHeapRegion::region_size_bytes()); |
| } |
| |
| void ShenandoahHeapRegion::set_state(RegionState to) { |
| EventShenandoahHeapRegionStateChange evt; |
| if (evt.should_commit()){ |
| evt.set_index((unsigned)region_number()); |
| evt.set_start((uintptr_t)bottom()); |
| evt.set_used(used()); |
| evt.set_from(_state); |
| evt.set_to(to); |
| evt.commit(); |
| } |
| _state = to; |
| } |