author | jrose |
Wed, 02 Jun 2010 22:45:42 -0700 | |
changeset 5702 | 201c5cde25bb |
parent 5547 | f4b087cbb361 |
parent 5694 | 1e0532a6abff |
child 6258 | 68f252c6e825 |
permissions | -rw-r--r-- |
1 | 1 |
/* |
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* Copyright (c) 2001, 2009, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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* |
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*/ |
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||
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# include "incls/_precompiled.incl" |
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# include "incls/_compactibleFreeListSpace.cpp.incl" |
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///////////////////////////////////////////////////////////////////////// |
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//// CompactibleFreeListSpace |
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///////////////////////////////////////////////////////////////////////// |
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||
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// highest ranked free list lock rank |
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int CompactibleFreeListSpace::_lockRank = Mutex::leaf + 3; |
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// Defaults are 0 so things will break badly if incorrectly initialized. |
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int CompactibleFreeListSpace::IndexSetStart = 0; |
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int CompactibleFreeListSpace::IndexSetStride = 0; |
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size_t MinChunkSize = 0; |
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void CompactibleFreeListSpace::set_cms_values() { |
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// Set CMS global values |
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assert(MinChunkSize == 0, "already set"); |
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#define numQuanta(x,y) ((x+y-1)/y) |
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MinChunkSize = numQuanta(sizeof(FreeChunk), MinObjAlignmentInBytes) * MinObjAlignment; |
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assert(IndexSetStart == 0 && IndexSetStride == 0, "already set"); |
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IndexSetStart = MinObjAlignment; |
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IndexSetStride = MinObjAlignment; |
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} |
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// Constructor |
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CompactibleFreeListSpace::CompactibleFreeListSpace(BlockOffsetSharedArray* bs, |
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MemRegion mr, bool use_adaptive_freelists, |
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FreeBlockDictionary::DictionaryChoice dictionaryChoice) : |
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_dictionaryChoice(dictionaryChoice), |
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_adaptive_freelists(use_adaptive_freelists), |
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_bt(bs, mr), |
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// free list locks are in the range of values taken by _lockRank |
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// This range currently is [_leaf+2, _leaf+3] |
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// Note: this requires that CFLspace c'tors |
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// are called serially in the order in which the locks are |
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// are acquired in the program text. This is true today. |
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_freelistLock(_lockRank--, "CompactibleFreeListSpace._lock", true), |
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_parDictionaryAllocLock(Mutex::leaf - 1, // == rank(ExpandHeap_lock) - 1 |
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"CompactibleFreeListSpace._dict_par_lock", true), |
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_rescan_task_size(CardTableModRefBS::card_size_in_words * BitsPerWord * |
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CMSRescanMultiple), |
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_marking_task_size(CardTableModRefBS::card_size_in_words * BitsPerWord * |
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CMSConcMarkMultiple), |
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_collector(NULL) |
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{ |
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_bt.set_space(this); |
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initialize(mr, SpaceDecorator::Clear, SpaceDecorator::Mangle); |
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// We have all of "mr", all of which we place in the dictionary |
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// as one big chunk. We'll need to decide here which of several |
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// possible alternative dictionary implementations to use. For |
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// now the choice is easy, since we have only one working |
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// implementation, namely, the simple binary tree (splaying |
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// temporarily disabled). |
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switch (dictionaryChoice) { |
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case FreeBlockDictionary::dictionarySplayTree: |
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case FreeBlockDictionary::dictionarySkipList: |
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default: |
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warning("dictionaryChoice: selected option not understood; using" |
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" default BinaryTreeDictionary implementation instead."); |
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case FreeBlockDictionary::dictionaryBinaryTree: |
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_dictionary = new BinaryTreeDictionary(mr); |
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break; |
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} |
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assert(_dictionary != NULL, "CMS dictionary initialization"); |
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// The indexed free lists are initially all empty and are lazily |
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// filled in on demand. Initialize the array elements to NULL. |
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initializeIndexedFreeListArray(); |
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// Not using adaptive free lists assumes that allocation is first |
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// from the linAB's. Also a cms perm gen which can be compacted |
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// has to have the klass's klassKlass allocated at a lower |
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// address in the heap than the klass so that the klassKlass is |
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// moved to its new location before the klass is moved. |
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// Set the _refillSize for the linear allocation blocks |
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if (!use_adaptive_freelists) { |
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FreeChunk* fc = _dictionary->getChunk(mr.word_size()); |
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// The small linAB initially has all the space and will allocate |
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// a chunk of any size. |
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HeapWord* addr = (HeapWord*) fc; |
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_smallLinearAllocBlock.set(addr, fc->size() , |
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1024*SmallForLinearAlloc, fc->size()); |
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// Note that _unallocated_block is not updated here. |
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// Allocations from the linear allocation block should |
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// update it. |
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} else { |
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_smallLinearAllocBlock.set(0, 0, 1024*SmallForLinearAlloc, |
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SmallForLinearAlloc); |
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} |
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// CMSIndexedFreeListReplenish should be at least 1 |
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CMSIndexedFreeListReplenish = MAX2((uintx)1, CMSIndexedFreeListReplenish); |
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_promoInfo.setSpace(this); |
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if (UseCMSBestFit) { |
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_fitStrategy = FreeBlockBestFitFirst; |
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} else { |
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_fitStrategy = FreeBlockStrategyNone; |
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} |
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checkFreeListConsistency(); |
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// Initialize locks for parallel case. |
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if (ParallelGCThreads > 0) { |
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for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
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_indexedFreeListParLocks[i] = new Mutex(Mutex::leaf - 1, // == ExpandHeap_lock - 1 |
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"a freelist par lock", |
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true); |
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if (_indexedFreeListParLocks[i] == NULL) |
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vm_exit_during_initialization("Could not allocate a par lock"); |
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DEBUG_ONLY( |
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_indexedFreeList[i].set_protecting_lock(_indexedFreeListParLocks[i]); |
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) |
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} |
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_dictionary->set_par_lock(&_parDictionaryAllocLock); |
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} |
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} |
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// Like CompactibleSpace forward() but always calls cross_threshold() to |
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// update the block offset table. Removed initialize_threshold call because |
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// CFLS does not use a block offset array for contiguous spaces. |
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HeapWord* CompactibleFreeListSpace::forward(oop q, size_t size, |
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CompactPoint* cp, HeapWord* compact_top) { |
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// q is alive |
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// First check if we should switch compaction space |
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assert(this == cp->space, "'this' should be current compaction space."); |
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size_t compaction_max_size = pointer_delta(end(), compact_top); |
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assert(adjustObjectSize(size) == cp->space->adjust_object_size_v(size), |
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"virtual adjustObjectSize_v() method is not correct"); |
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size_t adjusted_size = adjustObjectSize(size); |
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assert(compaction_max_size >= MinChunkSize || compaction_max_size == 0, |
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"no small fragments allowed"); |
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assert(minimum_free_block_size() == MinChunkSize, |
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"for de-virtualized reference below"); |
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// Can't leave a nonzero size, residual fragment smaller than MinChunkSize |
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if (adjusted_size + MinChunkSize > compaction_max_size && |
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adjusted_size != compaction_max_size) { |
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do { |
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// switch to next compaction space |
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cp->space->set_compaction_top(compact_top); |
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cp->space = cp->space->next_compaction_space(); |
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if (cp->space == NULL) { |
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cp->gen = GenCollectedHeap::heap()->prev_gen(cp->gen); |
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assert(cp->gen != NULL, "compaction must succeed"); |
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cp->space = cp->gen->first_compaction_space(); |
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assert(cp->space != NULL, "generation must have a first compaction space"); |
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} |
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compact_top = cp->space->bottom(); |
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cp->space->set_compaction_top(compact_top); |
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// The correct adjusted_size may not be the same as that for this method |
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// (i.e., cp->space may no longer be "this" so adjust the size again. |
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// Use the virtual method which is not used above to save the virtual |
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// dispatch. |
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adjusted_size = cp->space->adjust_object_size_v(size); |
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compaction_max_size = pointer_delta(cp->space->end(), compact_top); |
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assert(cp->space->minimum_free_block_size() == 0, "just checking"); |
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} while (adjusted_size > compaction_max_size); |
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} |
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// store the forwarding pointer into the mark word |
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if ((HeapWord*)q != compact_top) { |
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q->forward_to(oop(compact_top)); |
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assert(q->is_gc_marked(), "encoding the pointer should preserve the mark"); |
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} else { |
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// if the object isn't moving we can just set the mark to the default |
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// mark and handle it specially later on. |
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q->init_mark(); |
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assert(q->forwardee() == NULL, "should be forwarded to NULL"); |
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} |
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VALIDATE_MARK_SWEEP_ONLY(MarkSweep::register_live_oop(q, adjusted_size)); |
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compact_top += adjusted_size; |
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// we need to update the offset table so that the beginnings of objects can be |
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// found during scavenge. Note that we are updating the offset table based on |
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// where the object will be once the compaction phase finishes. |
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// Always call cross_threshold(). A contiguous space can only call it when |
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// the compaction_top exceeds the current threshold but not for an |
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// non-contiguous space. |
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cp->threshold = |
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cp->space->cross_threshold(compact_top - adjusted_size, compact_top); |
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return compact_top; |
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} |
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// A modified copy of OffsetTableContigSpace::cross_threshold() with _offsets -> _bt |
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// and use of single_block instead of alloc_block. The name here is not really |
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// appropriate - maybe a more general name could be invented for both the |
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// contiguous and noncontiguous spaces. |
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HeapWord* CompactibleFreeListSpace::cross_threshold(HeapWord* start, HeapWord* the_end) { |
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_bt.single_block(start, the_end); |
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return end(); |
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} |
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// Initialize them to NULL. |
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void CompactibleFreeListSpace::initializeIndexedFreeListArray() { |
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for (size_t i = 0; i < IndexSetSize; i++) { |
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// Note that on platforms where objects are double word aligned, |
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// the odd array elements are not used. It is convenient, however, |
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// to map directly from the object size to the array element. |
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_indexedFreeList[i].reset(IndexSetSize); |
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_indexedFreeList[i].set_size(i); |
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assert(_indexedFreeList[i].count() == 0, "reset check failed"); |
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assert(_indexedFreeList[i].head() == NULL, "reset check failed"); |
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assert(_indexedFreeList[i].tail() == NULL, "reset check failed"); |
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assert(_indexedFreeList[i].hint() == IndexSetSize, "reset check failed"); |
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} |
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} |
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void CompactibleFreeListSpace::resetIndexedFreeListArray() { |
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for (int i = 1; i < IndexSetSize; i++) { |
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assert(_indexedFreeList[i].size() == (size_t) i, |
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"Indexed free list sizes are incorrect"); |
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_indexedFreeList[i].reset(IndexSetSize); |
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assert(_indexedFreeList[i].count() == 0, "reset check failed"); |
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assert(_indexedFreeList[i].head() == NULL, "reset check failed"); |
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assert(_indexedFreeList[i].tail() == NULL, "reset check failed"); |
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assert(_indexedFreeList[i].hint() == IndexSetSize, "reset check failed"); |
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} |
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} |
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void CompactibleFreeListSpace::reset(MemRegion mr) { |
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resetIndexedFreeListArray(); |
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dictionary()->reset(); |
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if (BlockOffsetArrayUseUnallocatedBlock) { |
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assert(end() == mr.end(), "We are compacting to the bottom of CMS gen"); |
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// Everything's allocated until proven otherwise. |
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_bt.set_unallocated_block(end()); |
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} |
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if (!mr.is_empty()) { |
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assert(mr.word_size() >= MinChunkSize, "Chunk size is too small"); |
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_bt.single_block(mr.start(), mr.word_size()); |
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FreeChunk* fc = (FreeChunk*) mr.start(); |
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fc->setSize(mr.word_size()); |
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if (mr.word_size() >= IndexSetSize ) { |
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returnChunkToDictionary(fc); |
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} else { |
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_bt.verify_not_unallocated((HeapWord*)fc, fc->size()); |
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_indexedFreeList[mr.word_size()].returnChunkAtHead(fc); |
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} |
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} |
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_promoInfo.reset(); |
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_smallLinearAllocBlock._ptr = NULL; |
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_smallLinearAllocBlock._word_size = 0; |
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} |
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void CompactibleFreeListSpace::reset_after_compaction() { |
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// Reset the space to the new reality - one free chunk. |
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MemRegion mr(compaction_top(), end()); |
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reset(mr); |
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// Now refill the linear allocation block(s) if possible. |
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276 |
if (_adaptive_freelists) { |
|
277 |
refillLinearAllocBlocksIfNeeded(); |
|
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} else { |
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279 |
// Place as much of mr in the linAB as we can get, |
|
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// provided it was big enough to go into the dictionary. |
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281 |
FreeChunk* fc = dictionary()->findLargestDict(); |
|
282 |
if (fc != NULL) { |
|
283 |
assert(fc->size() == mr.word_size(), |
|
284 |
"Why was the chunk broken up?"); |
|
285 |
removeChunkFromDictionary(fc); |
|
286 |
HeapWord* addr = (HeapWord*) fc; |
|
287 |
_smallLinearAllocBlock.set(addr, fc->size() , |
|
288 |
1024*SmallForLinearAlloc, fc->size()); |
|
289 |
// Note that _unallocated_block is not updated here. |
|
290 |
} |
|
291 |
} |
|
292 |
} |
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293 |
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294 |
// Walks the entire dictionary, returning a coterminal |
|
295 |
// chunk, if it exists. Use with caution since it involves |
|
296 |
// a potentially complete walk of a potentially large tree. |
|
297 |
FreeChunk* CompactibleFreeListSpace::find_chunk_at_end() { |
|
298 |
||
299 |
assert_lock_strong(&_freelistLock); |
|
300 |
||
301 |
return dictionary()->find_chunk_ends_at(end()); |
|
302 |
} |
|
303 |
||
304 |
||
305 |
#ifndef PRODUCT |
|
306 |
void CompactibleFreeListSpace::initializeIndexedFreeListArrayReturnedBytes() { |
|
307 |
for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
|
308 |
_indexedFreeList[i].allocation_stats()->set_returnedBytes(0); |
|
309 |
} |
|
310 |
} |
|
311 |
||
312 |
size_t CompactibleFreeListSpace::sumIndexedFreeListArrayReturnedBytes() { |
|
313 |
size_t sum = 0; |
|
314 |
for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
|
315 |
sum += _indexedFreeList[i].allocation_stats()->returnedBytes(); |
|
316 |
} |
|
317 |
return sum; |
|
318 |
} |
|
319 |
||
320 |
size_t CompactibleFreeListSpace::totalCountInIndexedFreeLists() const { |
|
321 |
size_t count = 0; |
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for (int i = (int)MinChunkSize; i < IndexSetSize; i++) { |
1 | 323 |
debug_only( |
324 |
ssize_t total_list_count = 0; |
|
325 |
for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
|
326 |
fc = fc->next()) { |
|
327 |
total_list_count++; |
|
328 |
} |
|
329 |
assert(total_list_count == _indexedFreeList[i].count(), |
|
330 |
"Count in list is incorrect"); |
|
331 |
) |
|
332 |
count += _indexedFreeList[i].count(); |
|
333 |
} |
|
334 |
return count; |
|
335 |
} |
|
336 |
||
337 |
size_t CompactibleFreeListSpace::totalCount() { |
|
338 |
size_t num = totalCountInIndexedFreeLists(); |
|
339 |
num += dictionary()->totalCount(); |
|
340 |
if (_smallLinearAllocBlock._word_size != 0) { |
|
341 |
num++; |
|
342 |
} |
|
343 |
return num; |
|
344 |
} |
|
345 |
#endif |
|
346 |
||
347 |
bool CompactibleFreeListSpace::is_free_block(const HeapWord* p) const { |
|
348 |
FreeChunk* fc = (FreeChunk*) p; |
|
349 |
return fc->isFree(); |
|
350 |
} |
|
351 |
||
352 |
size_t CompactibleFreeListSpace::used() const { |
|
353 |
return capacity() - free(); |
|
354 |
} |
|
355 |
||
356 |
size_t CompactibleFreeListSpace::free() const { |
|
357 |
// "MT-safe, but not MT-precise"(TM), if you will: i.e. |
|
358 |
// if you do this while the structures are in flux you |
|
359 |
// may get an approximate answer only; for instance |
|
360 |
// because there is concurrent allocation either |
|
361 |
// directly by mutators or for promotion during a GC. |
|
362 |
// It's "MT-safe", however, in the sense that you are guaranteed |
|
363 |
// not to crash and burn, for instance, because of walking |
|
364 |
// pointers that could disappear as you were walking them. |
|
365 |
// The approximation is because the various components |
|
366 |
// that are read below are not read atomically (and |
|
367 |
// further the computation of totalSizeInIndexedFreeLists() |
|
368 |
// is itself a non-atomic computation. The normal use of |
|
369 |
// this is during a resize operation at the end of GC |
|
370 |
// and at that time you are guaranteed to get the |
|
371 |
// correct actual value. However, for instance, this is |
|
372 |
// also read completely asynchronously by the "perf-sampler" |
|
373 |
// that supports jvmstat, and you are apt to see the values |
|
374 |
// flicker in such cases. |
|
375 |
assert(_dictionary != NULL, "No _dictionary?"); |
|
376 |
return (_dictionary->totalChunkSize(DEBUG_ONLY(freelistLock())) + |
|
377 |
totalSizeInIndexedFreeLists() + |
|
378 |
_smallLinearAllocBlock._word_size) * HeapWordSize; |
|
379 |
} |
|
380 |
||
381 |
size_t CompactibleFreeListSpace::max_alloc_in_words() const { |
|
382 |
assert(_dictionary != NULL, "No _dictionary?"); |
|
383 |
assert_locked(); |
|
384 |
size_t res = _dictionary->maxChunkSize(); |
|
385 |
res = MAX2(res, MIN2(_smallLinearAllocBlock._word_size, |
|
386 |
(size_t) SmallForLinearAlloc - 1)); |
|
387 |
// XXX the following could potentially be pretty slow; |
|
388 |
// should one, pesimally for the rare cases when res |
|
389 |
// caclulated above is less than IndexSetSize, |
|
390 |
// just return res calculated above? My reasoning was that |
|
391 |
// those cases will be so rare that the extra time spent doesn't |
|
392 |
// really matter.... |
|
393 |
// Note: do not change the loop test i >= res + IndexSetStride |
|
394 |
// to i > res below, because i is unsigned and res may be zero. |
|
395 |
for (size_t i = IndexSetSize - 1; i >= res + IndexSetStride; |
|
396 |
i -= IndexSetStride) { |
|
397 |
if (_indexedFreeList[i].head() != NULL) { |
|
398 |
assert(_indexedFreeList[i].count() != 0, "Inconsistent FreeList"); |
|
399 |
return i; |
|
400 |
} |
|
401 |
} |
|
402 |
return res; |
|
403 |
} |
|
404 |
||
4574
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405 |
void CompactibleFreeListSpace::print_indexed_free_lists(outputStream* st) |
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406 |
const { |
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407 |
reportIndexedFreeListStatistics(); |
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408 |
gclog_or_tty->print_cr("Layout of Indexed Freelists"); |
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409 |
gclog_or_tty->print_cr("---------------------------"); |
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410 |
FreeList::print_labels_on(st, "size"); |
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411 |
for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
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412 |
_indexedFreeList[i].print_on(gclog_or_tty); |
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413 |
for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
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414 |
fc = fc->next()) { |
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415 |
gclog_or_tty->print_cr("\t[" PTR_FORMAT "," PTR_FORMAT ") %s", |
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416 |
fc, (HeapWord*)fc + i, |
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417 |
fc->cantCoalesce() ? "\t CC" : ""); |
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|
418 |
} |
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|
419 |
} |
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|
420 |
} |
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|
421 |
|
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422 |
void CompactibleFreeListSpace::print_promo_info_blocks(outputStream* st) |
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|
423 |
const { |
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424 |
_promoInfo.print_on(st); |
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|
425 |
} |
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|
426 |
|
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|
427 |
void CompactibleFreeListSpace::print_dictionary_free_lists(outputStream* st) |
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|
428 |
const { |
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|
429 |
_dictionary->reportStatistics(); |
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|
430 |
st->print_cr("Layout of Freelists in Tree"); |
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|
431 |
st->print_cr("---------------------------"); |
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|
432 |
_dictionary->print_free_lists(st); |
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|
433 |
} |
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|
434 |
|
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435 |
class BlkPrintingClosure: public BlkClosure { |
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|
436 |
const CMSCollector* _collector; |
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|
437 |
const CompactibleFreeListSpace* _sp; |
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438 |
const CMSBitMap* _live_bit_map; |
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|
439 |
const bool _post_remark; |
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|
440 |
outputStream* _st; |
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|
441 |
public: |
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|
442 |
BlkPrintingClosure(const CMSCollector* collector, |
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|
443 |
const CompactibleFreeListSpace* sp, |
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|
444 |
const CMSBitMap* live_bit_map, |
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|
445 |
outputStream* st): |
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|
446 |
_collector(collector), |
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|
447 |
_sp(sp), |
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|
448 |
_live_bit_map(live_bit_map), |
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|
449 |
_post_remark(collector->abstract_state() > CMSCollector::FinalMarking), |
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|
450 |
_st(st) { } |
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|
451 |
size_t do_blk(HeapWord* addr); |
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|
452 |
}; |
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|
453 |
|
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|
454 |
size_t BlkPrintingClosure::do_blk(HeapWord* addr) { |
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|
455 |
size_t sz = _sp->block_size_no_stall(addr, _collector); |
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|
456 |
assert(sz != 0, "Should always be able to compute a size"); |
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|
457 |
if (_sp->block_is_obj(addr)) { |
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|
458 |
const bool dead = _post_remark && !_live_bit_map->isMarked(addr); |
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|
459 |
_st->print_cr(PTR_FORMAT ": %s object of size " SIZE_FORMAT "%s", |
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|
460 |
addr, |
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|
461 |
dead ? "dead" : "live", |
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|
462 |
sz, |
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|
463 |
(!dead && CMSPrintObjectsInDump) ? ":" : "."); |
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|
464 |
if (CMSPrintObjectsInDump && !dead) { |
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|
465 |
oop(addr)->print_on(_st); |
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|
466 |
_st->print_cr("--------------------------------------"); |
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|
467 |
} |
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|
468 |
} else { // free block |
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|
469 |
_st->print_cr(PTR_FORMAT ": free block of size " SIZE_FORMAT "%s", |
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|
470 |
addr, sz, CMSPrintChunksInDump ? ":" : "."); |
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|
471 |
if (CMSPrintChunksInDump) { |
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|
472 |
((FreeChunk*)addr)->print_on(_st); |
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|
473 |
_st->print_cr("--------------------------------------"); |
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|
474 |
} |
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|
475 |
} |
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|
476 |
return sz; |
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|
477 |
} |
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|
478 |
|
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|
479 |
void CompactibleFreeListSpace::dump_at_safepoint_with_locks(CMSCollector* c, |
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|
480 |
outputStream* st) { |
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|
481 |
st->print_cr("\n========================="); |
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|
482 |
st->print_cr("Block layout in CMS Heap:"); |
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|
483 |
st->print_cr("========================="); |
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|
484 |
BlkPrintingClosure bpcl(c, this, c->markBitMap(), st); |
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|
485 |
blk_iterate(&bpcl); |
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|
486 |
|
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|
487 |
st->print_cr("\n======================================="); |
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|
488 |
st->print_cr("Order & Layout of Promotion Info Blocks"); |
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|
489 |
st->print_cr("======================================="); |
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|
490 |
print_promo_info_blocks(st); |
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|
491 |
|
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|
492 |
st->print_cr("\n==========================="); |
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|
493 |
st->print_cr("Order of Indexed Free Lists"); |
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|
494 |
st->print_cr("========================="); |
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|
495 |
print_indexed_free_lists(st); |
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|
496 |
|
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|
497 |
st->print_cr("\n================================="); |
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|
498 |
st->print_cr("Order of Free Lists in Dictionary"); |
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|
499 |
st->print_cr("================================="); |
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|
500 |
print_dictionary_free_lists(st); |
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|
501 |
} |
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|
502 |
|
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|
503 |
|
1 | 504 |
void CompactibleFreeListSpace::reportFreeListStatistics() const { |
505 |
assert_lock_strong(&_freelistLock); |
|
506 |
assert(PrintFLSStatistics != 0, "Reporting error"); |
|
507 |
_dictionary->reportStatistics(); |
|
508 |
if (PrintFLSStatistics > 1) { |
|
509 |
reportIndexedFreeListStatistics(); |
|
510 |
size_t totalSize = totalSizeInIndexedFreeLists() + |
|
511 |
_dictionary->totalChunkSize(DEBUG_ONLY(freelistLock())); |
|
512 |
gclog_or_tty->print(" free=%ld frag=%1.4f\n", totalSize, flsFrag()); |
|
513 |
} |
|
514 |
} |
|
515 |
||
516 |
void CompactibleFreeListSpace::reportIndexedFreeListStatistics() const { |
|
517 |
assert_lock_strong(&_freelistLock); |
|
518 |
gclog_or_tty->print("Statistics for IndexedFreeLists:\n" |
|
519 |
"--------------------------------\n"); |
|
520 |
size_t totalSize = totalSizeInIndexedFreeLists(); |
|
521 |
size_t freeBlocks = numFreeBlocksInIndexedFreeLists(); |
|
522 |
gclog_or_tty->print("Total Free Space: %d\n", totalSize); |
|
523 |
gclog_or_tty->print("Max Chunk Size: %d\n", maxChunkSizeInIndexedFreeLists()); |
|
524 |
gclog_or_tty->print("Number of Blocks: %d\n", freeBlocks); |
|
525 |
if (freeBlocks != 0) { |
|
526 |
gclog_or_tty->print("Av. Block Size: %d\n", totalSize/freeBlocks); |
|
527 |
} |
|
528 |
} |
|
529 |
||
530 |
size_t CompactibleFreeListSpace::numFreeBlocksInIndexedFreeLists() const { |
|
531 |
size_t res = 0; |
|
532 |
for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
|
533 |
debug_only( |
|
534 |
ssize_t recount = 0; |
|
535 |
for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
|
536 |
fc = fc->next()) { |
|
537 |
recount += 1; |
|
538 |
} |
|
539 |
assert(recount == _indexedFreeList[i].count(), |
|
540 |
"Incorrect count in list"); |
|
541 |
) |
|
542 |
res += _indexedFreeList[i].count(); |
|
543 |
} |
|
544 |
return res; |
|
545 |
} |
|
546 |
||
547 |
size_t CompactibleFreeListSpace::maxChunkSizeInIndexedFreeLists() const { |
|
548 |
for (size_t i = IndexSetSize - 1; i != 0; i -= IndexSetStride) { |
|
549 |
if (_indexedFreeList[i].head() != NULL) { |
|
550 |
assert(_indexedFreeList[i].count() != 0, "Inconsistent FreeList"); |
|
551 |
return (size_t)i; |
|
552 |
} |
|
553 |
} |
|
554 |
return 0; |
|
555 |
} |
|
556 |
||
557 |
void CompactibleFreeListSpace::set_end(HeapWord* value) { |
|
558 |
HeapWord* prevEnd = end(); |
|
559 |
assert(prevEnd != value, "unnecessary set_end call"); |
|
560 |
assert(prevEnd == NULL || value >= unallocated_block(), "New end is below unallocated block"); |
|
561 |
_end = value; |
|
562 |
if (prevEnd != NULL) { |
|
563 |
// Resize the underlying block offset table. |
|
564 |
_bt.resize(pointer_delta(value, bottom())); |
|
4574
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|
565 |
if (value <= prevEnd) { |
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|
566 |
assert(value >= unallocated_block(), "New end is below unallocated block"); |
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|
567 |
} else { |
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|
568 |
// Now, take this new chunk and add it to the free blocks. |
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|
569 |
// Note that the BOT has not yet been updated for this block. |
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|
570 |
size_t newFcSize = pointer_delta(value, prevEnd); |
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|
571 |
// XXX This is REALLY UGLY and should be fixed up. XXX |
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|
572 |
if (!_adaptive_freelists && _smallLinearAllocBlock._ptr == NULL) { |
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|
573 |
// Mark the boundary of the new block in BOT |
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|
574 |
_bt.mark_block(prevEnd, value); |
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|
575 |
// put it all in the linAB |
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|
576 |
if (ParallelGCThreads == 0) { |
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|
577 |
_smallLinearAllocBlock._ptr = prevEnd; |
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|
578 |
_smallLinearAllocBlock._word_size = newFcSize; |
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|
579 |
repairLinearAllocBlock(&_smallLinearAllocBlock); |
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|
580 |
} else { // ParallelGCThreads > 0 |
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|
581 |
MutexLockerEx x(parDictionaryAllocLock(), |
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|
582 |
Mutex::_no_safepoint_check_flag); |
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|
583 |
_smallLinearAllocBlock._ptr = prevEnd; |
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|
584 |
_smallLinearAllocBlock._word_size = newFcSize; |
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|
585 |
repairLinearAllocBlock(&_smallLinearAllocBlock); |
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|
586 |
} |
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|
587 |
// Births of chunks put into a LinAB are not recorded. Births |
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|
588 |
// of chunks as they are allocated out of a LinAB are. |
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|
589 |
} else { |
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|
590 |
// Add the block to the free lists, if possible coalescing it |
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|
591 |
// with the last free block, and update the BOT and census data. |
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|
592 |
addChunkToFreeListsAtEndRecordingStats(prevEnd, newFcSize); |
1 | 593 |
} |
594 |
} |
|
595 |
} |
|
596 |
} |
|
597 |
||
598 |
class FreeListSpace_DCTOC : public Filtering_DCTOC { |
|
599 |
CompactibleFreeListSpace* _cfls; |
|
600 |
CMSCollector* _collector; |
|
601 |
protected: |
|
602 |
// Override. |
|
603 |
#define walk_mem_region_with_cl_DECL(ClosureType) \ |
|
604 |
virtual void walk_mem_region_with_cl(MemRegion mr, \ |
|
605 |
HeapWord* bottom, HeapWord* top, \ |
|
606 |
ClosureType* cl); \ |
|
607 |
void walk_mem_region_with_cl_par(MemRegion mr, \ |
|
608 |
HeapWord* bottom, HeapWord* top, \ |
|
609 |
ClosureType* cl); \ |
|
610 |
void walk_mem_region_with_cl_nopar(MemRegion mr, \ |
|
611 |
HeapWord* bottom, HeapWord* top, \ |
|
612 |
ClosureType* cl) |
|
613 |
walk_mem_region_with_cl_DECL(OopClosure); |
|
614 |
walk_mem_region_with_cl_DECL(FilteringClosure); |
|
615 |
||
616 |
public: |
|
617 |
FreeListSpace_DCTOC(CompactibleFreeListSpace* sp, |
|
618 |
CMSCollector* collector, |
|
619 |
OopClosure* cl, |
|
620 |
CardTableModRefBS::PrecisionStyle precision, |
|
621 |
HeapWord* boundary) : |
|
622 |
Filtering_DCTOC(sp, cl, precision, boundary), |
|
623 |
_cfls(sp), _collector(collector) {} |
|
624 |
}; |
|
625 |
||
626 |
// We de-virtualize the block-related calls below, since we know that our |
|
627 |
// space is a CompactibleFreeListSpace. |
|
628 |
#define FreeListSpace_DCTOC__walk_mem_region_with_cl_DEFN(ClosureType) \ |
|
629 |
void FreeListSpace_DCTOC::walk_mem_region_with_cl(MemRegion mr, \ |
|
630 |
HeapWord* bottom, \ |
|
631 |
HeapWord* top, \ |
|
632 |
ClosureType* cl) { \ |
|
633 |
if (SharedHeap::heap()->n_par_threads() > 0) { \ |
|
634 |
walk_mem_region_with_cl_par(mr, bottom, top, cl); \ |
|
635 |
} else { \ |
|
636 |
walk_mem_region_with_cl_nopar(mr, bottom, top, cl); \ |
|
637 |
} \ |
|
638 |
} \ |
|
639 |
void FreeListSpace_DCTOC::walk_mem_region_with_cl_par(MemRegion mr, \ |
|
640 |
HeapWord* bottom, \ |
|
641 |
HeapWord* top, \ |
|
642 |
ClosureType* cl) { \ |
|
643 |
/* Skip parts that are before "mr", in case "block_start" sent us \ |
|
644 |
back too far. */ \ |
|
645 |
HeapWord* mr_start = mr.start(); \ |
|
646 |
size_t bot_size = _cfls->CompactibleFreeListSpace::block_size(bottom); \ |
|
647 |
HeapWord* next = bottom + bot_size; \ |
|
648 |
while (next < mr_start) { \ |
|
649 |
bottom = next; \ |
|
650 |
bot_size = _cfls->CompactibleFreeListSpace::block_size(bottom); \ |
|
651 |
next = bottom + bot_size; \ |
|
652 |
} \ |
|
653 |
\ |
|
654 |
while (bottom < top) { \ |
|
655 |
if (_cfls->CompactibleFreeListSpace::block_is_obj(bottom) && \ |
|
656 |
!_cfls->CompactibleFreeListSpace::obj_allocated_since_save_marks( \ |
|
657 |
oop(bottom)) && \ |
|
658 |
!_collector->CMSCollector::is_dead_obj(oop(bottom))) { \ |
|
659 |
size_t word_sz = oop(bottom)->oop_iterate(cl, mr); \ |
|
660 |
bottom += _cfls->adjustObjectSize(word_sz); \ |
|
661 |
} else { \ |
|
662 |
bottom += _cfls->CompactibleFreeListSpace::block_size(bottom); \ |
|
663 |
} \ |
|
664 |
} \ |
|
665 |
} \ |
|
666 |
void FreeListSpace_DCTOC::walk_mem_region_with_cl_nopar(MemRegion mr, \ |
|
667 |
HeapWord* bottom, \ |
|
668 |
HeapWord* top, \ |
|
669 |
ClosureType* cl) { \ |
|
670 |
/* Skip parts that are before "mr", in case "block_start" sent us \ |
|
671 |
back too far. */ \ |
|
672 |
HeapWord* mr_start = mr.start(); \ |
|
673 |
size_t bot_size = _cfls->CompactibleFreeListSpace::block_size_nopar(bottom); \ |
|
674 |
HeapWord* next = bottom + bot_size; \ |
|
675 |
while (next < mr_start) { \ |
|
676 |
bottom = next; \ |
|
677 |
bot_size = _cfls->CompactibleFreeListSpace::block_size_nopar(bottom); \ |
|
678 |
next = bottom + bot_size; \ |
|
679 |
} \ |
|
680 |
\ |
|
681 |
while (bottom < top) { \ |
|
682 |
if (_cfls->CompactibleFreeListSpace::block_is_obj_nopar(bottom) && \ |
|
683 |
!_cfls->CompactibleFreeListSpace::obj_allocated_since_save_marks( \ |
|
684 |
oop(bottom)) && \ |
|
685 |
!_collector->CMSCollector::is_dead_obj(oop(bottom))) { \ |
|
686 |
size_t word_sz = oop(bottom)->oop_iterate(cl, mr); \ |
|
687 |
bottom += _cfls->adjustObjectSize(word_sz); \ |
|
688 |
} else { \ |
|
689 |
bottom += _cfls->CompactibleFreeListSpace::block_size_nopar(bottom); \ |
|
690 |
} \ |
|
691 |
} \ |
|
692 |
} |
|
693 |
||
694 |
// (There are only two of these, rather than N, because the split is due |
|
695 |
// only to the introduction of the FilteringClosure, a local part of the |
|
696 |
// impl of this abstraction.) |
|
697 |
FreeListSpace_DCTOC__walk_mem_region_with_cl_DEFN(OopClosure) |
|
698 |
FreeListSpace_DCTOC__walk_mem_region_with_cl_DEFN(FilteringClosure) |
|
699 |
||
700 |
DirtyCardToOopClosure* |
|
701 |
CompactibleFreeListSpace::new_dcto_cl(OopClosure* cl, |
|
702 |
CardTableModRefBS::PrecisionStyle precision, |
|
703 |
HeapWord* boundary) { |
|
704 |
return new FreeListSpace_DCTOC(this, _collector, cl, precision, boundary); |
|
705 |
} |
|
706 |
||
707 |
||
708 |
// Note on locking for the space iteration functions: |
|
709 |
// since the collector's iteration activities are concurrent with |
|
710 |
// allocation activities by mutators, absent a suitable mutual exclusion |
|
711 |
// mechanism the iterators may go awry. For instace a block being iterated |
|
712 |
// may suddenly be allocated or divided up and part of it allocated and |
|
713 |
// so on. |
|
714 |
||
715 |
// Apply the given closure to each block in the space. |
|
716 |
void CompactibleFreeListSpace::blk_iterate_careful(BlkClosureCareful* cl) { |
|
717 |
assert_lock_strong(freelistLock()); |
|
718 |
HeapWord *cur, *limit; |
|
719 |
for (cur = bottom(), limit = end(); cur < limit; |
|
720 |
cur += cl->do_blk_careful(cur)); |
|
721 |
} |
|
722 |
||
723 |
// Apply the given closure to each block in the space. |
|
724 |
void CompactibleFreeListSpace::blk_iterate(BlkClosure* cl) { |
|
725 |
assert_lock_strong(freelistLock()); |
|
726 |
HeapWord *cur, *limit; |
|
727 |
for (cur = bottom(), limit = end(); cur < limit; |
|
728 |
cur += cl->do_blk(cur)); |
|
729 |
} |
|
730 |
||
731 |
// Apply the given closure to each oop in the space. |
|
732 |
void CompactibleFreeListSpace::oop_iterate(OopClosure* cl) { |
|
733 |
assert_lock_strong(freelistLock()); |
|
734 |
HeapWord *cur, *limit; |
|
735 |
size_t curSize; |
|
736 |
for (cur = bottom(), limit = end(); cur < limit; |
|
737 |
cur += curSize) { |
|
738 |
curSize = block_size(cur); |
|
739 |
if (block_is_obj(cur)) { |
|
740 |
oop(cur)->oop_iterate(cl); |
|
741 |
} |
|
742 |
} |
|
743 |
} |
|
744 |
||
745 |
// Apply the given closure to each oop in the space \intersect memory region. |
|
746 |
void CompactibleFreeListSpace::oop_iterate(MemRegion mr, OopClosure* cl) { |
|
747 |
assert_lock_strong(freelistLock()); |
|
748 |
if (is_empty()) { |
|
749 |
return; |
|
750 |
} |
|
751 |
MemRegion cur = MemRegion(bottom(), end()); |
|
752 |
mr = mr.intersection(cur); |
|
753 |
if (mr.is_empty()) { |
|
754 |
return; |
|
755 |
} |
|
756 |
if (mr.equals(cur)) { |
|
757 |
oop_iterate(cl); |
|
758 |
return; |
|
759 |
} |
|
760 |
assert(mr.end() <= end(), "just took an intersection above"); |
|
761 |
HeapWord* obj_addr = block_start(mr.start()); |
|
762 |
HeapWord* t = mr.end(); |
|
763 |
||
764 |
SpaceMemRegionOopsIterClosure smr_blk(cl, mr); |
|
765 |
if (block_is_obj(obj_addr)) { |
|
766 |
// Handle first object specially. |
|
767 |
oop obj = oop(obj_addr); |
|
768 |
obj_addr += adjustObjectSize(obj->oop_iterate(&smr_blk)); |
|
769 |
} else { |
|
770 |
FreeChunk* fc = (FreeChunk*)obj_addr; |
|
771 |
obj_addr += fc->size(); |
|
772 |
} |
|
773 |
while (obj_addr < t) { |
|
774 |
HeapWord* obj = obj_addr; |
|
775 |
obj_addr += block_size(obj_addr); |
|
776 |
// If "obj_addr" is not greater than top, then the |
|
777 |
// entire object "obj" is within the region. |
|
778 |
if (obj_addr <= t) { |
|
779 |
if (block_is_obj(obj)) { |
|
780 |
oop(obj)->oop_iterate(cl); |
|
781 |
} |
|
782 |
} else { |
|
783 |
// "obj" extends beyond end of region |
|
784 |
if (block_is_obj(obj)) { |
|
785 |
oop(obj)->oop_iterate(&smr_blk); |
|
786 |
} |
|
787 |
break; |
|
788 |
} |
|
789 |
} |
|
790 |
} |
|
791 |
||
792 |
// NOTE: In the following methods, in order to safely be able to |
|
793 |
// apply the closure to an object, we need to be sure that the |
|
794 |
// object has been initialized. We are guaranteed that an object |
|
795 |
// is initialized if we are holding the Heap_lock with the |
|
796 |
// world stopped. |
|
797 |
void CompactibleFreeListSpace::verify_objects_initialized() const { |
|
798 |
if (is_init_completed()) { |
|
799 |
assert_locked_or_safepoint(Heap_lock); |
|
800 |
if (Universe::is_fully_initialized()) { |
|
801 |
guarantee(SafepointSynchronize::is_at_safepoint(), |
|
802 |
"Required for objects to be initialized"); |
|
803 |
} |
|
804 |
} // else make a concession at vm start-up |
|
805 |
} |
|
806 |
||
807 |
// Apply the given closure to each object in the space |
|
808 |
void CompactibleFreeListSpace::object_iterate(ObjectClosure* blk) { |
|
809 |
assert_lock_strong(freelistLock()); |
|
810 |
NOT_PRODUCT(verify_objects_initialized()); |
|
811 |
HeapWord *cur, *limit; |
|
812 |
size_t curSize; |
|
813 |
for (cur = bottom(), limit = end(); cur < limit; |
|
814 |
cur += curSize) { |
|
815 |
curSize = block_size(cur); |
|
816 |
if (block_is_obj(cur)) { |
|
817 |
blk->do_object(oop(cur)); |
|
818 |
} |
|
819 |
} |
|
820 |
} |
|
821 |
||
1893
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6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
1392
diff
changeset
|
822 |
// Apply the given closure to each live object in the space |
c82e388e17c5
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jmasa
parents:
1392
diff
changeset
|
823 |
// The usage of CompactibleFreeListSpace |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
1392
diff
changeset
|
824 |
// by the ConcurrentMarkSweepGeneration for concurrent GC's allows |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
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1392
diff
changeset
|
825 |
// objects in the space with references to objects that are no longer |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
1392
diff
changeset
|
826 |
// valid. For example, an object may reference another object |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
1392
diff
changeset
|
827 |
// that has already been sweep up (collected). This method uses |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
1392
diff
changeset
|
828 |
// obj_is_alive() to determine whether it is safe to apply the closure to |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
1392
diff
changeset
|
829 |
// an object. See obj_is_alive() for details on how liveness of an |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
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1392
diff
changeset
|
830 |
// object is decided. |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
jmasa
parents:
1392
diff
changeset
|
831 |
|
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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|
832 |
void CompactibleFreeListSpace::safe_object_iterate(ObjectClosure* blk) { |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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|
833 |
assert_lock_strong(freelistLock()); |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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|
834 |
NOT_PRODUCT(verify_objects_initialized()); |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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changeset
|
835 |
HeapWord *cur, *limit; |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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changeset
|
836 |
size_t curSize; |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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diff
changeset
|
837 |
for (cur = bottom(), limit = end(); cur < limit; |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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changeset
|
838 |
cur += curSize) { |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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diff
changeset
|
839 |
curSize = block_size(cur); |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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changeset
|
840 |
if (block_is_obj(cur) && obj_is_alive(cur)) { |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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changeset
|
841 |
blk->do_object(oop(cur)); |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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diff
changeset
|
842 |
} |
c82e388e17c5
6689653: JMapPerm fails with UseConcMarkSweepIncGC and compressed oops off
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changeset
|
843 |
} |
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changeset
|
844 |
} |
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changeset
|
845 |
|
1 | 846 |
void CompactibleFreeListSpace::object_iterate_mem(MemRegion mr, |
847 |
UpwardsObjectClosure* cl) { |
|
4574
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6631166: CMS: better heuristics when combatting fragmentation
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diff
changeset
|
848 |
assert_locked(freelistLock()); |
1 | 849 |
NOT_PRODUCT(verify_objects_initialized()); |
850 |
Space::object_iterate_mem(mr, cl); |
|
851 |
} |
|
852 |
||
853 |
// Callers of this iterator beware: The closure application should |
|
854 |
// be robust in the face of uninitialized objects and should (always) |
|
855 |
// return a correct size so that the next addr + size below gives us a |
|
856 |
// valid block boundary. [See for instance, |
|
857 |
// ScanMarkedObjectsAgainCarefullyClosure::do_object_careful() |
|
858 |
// in ConcurrentMarkSweepGeneration.cpp.] |
|
859 |
HeapWord* |
|
860 |
CompactibleFreeListSpace::object_iterate_careful(ObjectClosureCareful* cl) { |
|
861 |
assert_lock_strong(freelistLock()); |
|
862 |
HeapWord *addr, *last; |
|
863 |
size_t size; |
|
864 |
for (addr = bottom(), last = end(); |
|
865 |
addr < last; addr += size) { |
|
866 |
FreeChunk* fc = (FreeChunk*)addr; |
|
867 |
if (fc->isFree()) { |
|
868 |
// Since we hold the free list lock, which protects direct |
|
869 |
// allocation in this generation by mutators, a free object |
|
870 |
// will remain free throughout this iteration code. |
|
871 |
size = fc->size(); |
|
872 |
} else { |
|
873 |
// Note that the object need not necessarily be initialized, |
|
874 |
// because (for instance) the free list lock does NOT protect |
|
875 |
// object initialization. The closure application below must |
|
876 |
// therefore be correct in the face of uninitialized objects. |
|
877 |
size = cl->do_object_careful(oop(addr)); |
|
878 |
if (size == 0) { |
|
879 |
// An unparsable object found. Signal early termination. |
|
880 |
return addr; |
|
881 |
} |
|
882 |
} |
|
883 |
} |
|
884 |
return NULL; |
|
885 |
} |
|
886 |
||
887 |
// Callers of this iterator beware: The closure application should |
|
888 |
// be robust in the face of uninitialized objects and should (always) |
|
889 |
// return a correct size so that the next addr + size below gives us a |
|
890 |
// valid block boundary. [See for instance, |
|
891 |
// ScanMarkedObjectsAgainCarefullyClosure::do_object_careful() |
|
892 |
// in ConcurrentMarkSweepGeneration.cpp.] |
|
893 |
HeapWord* |
|
894 |
CompactibleFreeListSpace::object_iterate_careful_m(MemRegion mr, |
|
895 |
ObjectClosureCareful* cl) { |
|
896 |
assert_lock_strong(freelistLock()); |
|
897 |
// Can't use used_region() below because it may not necessarily |
|
898 |
// be the same as [bottom(),end()); although we could |
|
899 |
// use [used_region().start(),round_to(used_region().end(),CardSize)), |
|
900 |
// that appears too cumbersome, so we just do the simpler check |
|
901 |
// in the assertion below. |
|
902 |
assert(!mr.is_empty() && MemRegion(bottom(),end()).contains(mr), |
|
903 |
"mr should be non-empty and within used space"); |
|
904 |
HeapWord *addr, *end; |
|
905 |
size_t size; |
|
906 |
for (addr = block_start_careful(mr.start()), end = mr.end(); |
|
907 |
addr < end; addr += size) { |
|
908 |
FreeChunk* fc = (FreeChunk*)addr; |
|
909 |
if (fc->isFree()) { |
|
910 |
// Since we hold the free list lock, which protects direct |
|
911 |
// allocation in this generation by mutators, a free object |
|
912 |
// will remain free throughout this iteration code. |
|
913 |
size = fc->size(); |
|
914 |
} else { |
|
915 |
// Note that the object need not necessarily be initialized, |
|
916 |
// because (for instance) the free list lock does NOT protect |
|
917 |
// object initialization. The closure application below must |
|
918 |
// therefore be correct in the face of uninitialized objects. |
|
919 |
size = cl->do_object_careful_m(oop(addr), mr); |
|
920 |
if (size == 0) { |
|
921 |
// An unparsable object found. Signal early termination. |
|
922 |
return addr; |
|
923 |
} |
|
924 |
} |
|
925 |
} |
|
926 |
return NULL; |
|
927 |
} |
|
928 |
||
929 |
||
1374
4c24294029a9
6711316: Open source the Garbage-First garbage collector
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360
diff
changeset
|
930 |
HeapWord* CompactibleFreeListSpace::block_start_const(const void* p) const { |
1 | 931 |
NOT_PRODUCT(verify_objects_initialized()); |
932 |
return _bt.block_start(p); |
|
933 |
} |
|
934 |
||
935 |
HeapWord* CompactibleFreeListSpace::block_start_careful(const void* p) const { |
|
936 |
return _bt.block_start_careful(p); |
|
937 |
} |
|
938 |
||
939 |
size_t CompactibleFreeListSpace::block_size(const HeapWord* p) const { |
|
940 |
NOT_PRODUCT(verify_objects_initialized()); |
|
941 |
assert(MemRegion(bottom(), end()).contains(p), "p not in space"); |
|
942 |
// This must be volatile, or else there is a danger that the compiler |
|
943 |
// will compile the code below into a sometimes-infinite loop, by keeping |
|
944 |
// the value read the first time in a register. |
|
945 |
while (true) { |
|
946 |
// We must do this until we get a consistent view of the object. |
|
613 | 947 |
if (FreeChunk::indicatesFreeChunk(p)) { |
948 |
volatile FreeChunk* fc = (volatile FreeChunk*)p; |
|
949 |
size_t res = fc->size(); |
|
950 |
// If the object is still a free chunk, return the size, else it |
|
951 |
// has been allocated so try again. |
|
952 |
if (FreeChunk::indicatesFreeChunk(p)) { |
|
1 | 953 |
assert(res != 0, "Block size should not be 0"); |
954 |
return res; |
|
955 |
} |
|
613 | 956 |
} else { |
957 |
// must read from what 'p' points to in each loop. |
|
958 |
klassOop k = ((volatile oopDesc*)p)->klass_or_null(); |
|
959 |
if (k != NULL) { |
|
960 |
assert(k->is_oop(true /* ignore mark word */), "Should really be klass oop."); |
|
961 |
oop o = (oop)p; |
|
962 |
assert(o->is_parsable(), "Should be parsable"); |
|
963 |
assert(o->is_oop(true /* ignore mark word */), "Should be an oop."); |
|
964 |
size_t res = o->size_given_klass(k->klass_part()); |
|
965 |
res = adjustObjectSize(res); |
|
966 |
assert(res != 0, "Block size should not be 0"); |
|
967 |
return res; |
|
968 |
} |
|
1 | 969 |
} |
970 |
} |
|
971 |
} |
|
972 |
||
973 |
// A variant of the above that uses the Printezis bits for |
|
974 |
// unparsable but allocated objects. This avoids any possible |
|
975 |
// stalls waiting for mutators to initialize objects, and is |
|
976 |
// thus potentially faster than the variant above. However, |
|
977 |
// this variant may return a zero size for a block that is |
|
978 |
// under mutation and for which a consistent size cannot be |
|
979 |
// inferred without stalling; see CMSCollector::block_size_if_printezis_bits(). |
|
980 |
size_t CompactibleFreeListSpace::block_size_no_stall(HeapWord* p, |
|
981 |
const CMSCollector* c) |
|
982 |
const { |
|
983 |
assert(MemRegion(bottom(), end()).contains(p), "p not in space"); |
|
984 |
// This must be volatile, or else there is a danger that the compiler |
|
985 |
// will compile the code below into a sometimes-infinite loop, by keeping |
|
986 |
// the value read the first time in a register. |
|
987 |
DEBUG_ONLY(uint loops = 0;) |
|
988 |
while (true) { |
|
989 |
// We must do this until we get a consistent view of the object. |
|
613 | 990 |
if (FreeChunk::indicatesFreeChunk(p)) { |
991 |
volatile FreeChunk* fc = (volatile FreeChunk*)p; |
|
992 |
size_t res = fc->size(); |
|
993 |
if (FreeChunk::indicatesFreeChunk(p)) { |
|
1 | 994 |
assert(res != 0, "Block size should not be 0"); |
995 |
assert(loops == 0, "Should be 0"); |
|
996 |
return res; |
|
997 |
} |
|
998 |
} else { |
|
613 | 999 |
// must read from what 'p' points to in each loop. |
1000 |
klassOop k = ((volatile oopDesc*)p)->klass_or_null(); |
|
1894
5c343868d071
6692899: CMS: many vm.parallel_class_loading tests fail with assert "missing Printezis mark"
jmasa
parents:
1893
diff
changeset
|
1001 |
if (k != NULL && |
5c343868d071
6692899: CMS: many vm.parallel_class_loading tests fail with assert "missing Printezis mark"
jmasa
parents:
1893
diff
changeset
|
1002 |
((oopDesc*)p)->is_parsable() && |
5c343868d071
6692899: CMS: many vm.parallel_class_loading tests fail with assert "missing Printezis mark"
jmasa
parents:
1893
diff
changeset
|
1003 |
((oopDesc*)p)->is_conc_safe()) { |
613 | 1004 |
assert(k->is_oop(), "Should really be klass oop."); |
1005 |
oop o = (oop)p; |
|
1006 |
assert(o->is_oop(), "Should be an oop"); |
|
1007 |
size_t res = o->size_given_klass(k->klass_part()); |
|
1008 |
res = adjustObjectSize(res); |
|
1009 |
assert(res != 0, "Block size should not be 0"); |
|
1010 |
return res; |
|
1011 |
} else { |
|
1012 |
return c->block_size_if_printezis_bits(p); |
|
1013 |
} |
|
1 | 1014 |
} |
1015 |
assert(loops == 0, "Can loop at most once"); |
|
1016 |
DEBUG_ONLY(loops++;) |
|
1017 |
} |
|
1018 |
} |
|
1019 |
||
1020 |
size_t CompactibleFreeListSpace::block_size_nopar(const HeapWord* p) const { |
|
1021 |
NOT_PRODUCT(verify_objects_initialized()); |
|
1022 |
assert(MemRegion(bottom(), end()).contains(p), "p not in space"); |
|
1023 |
FreeChunk* fc = (FreeChunk*)p; |
|
1024 |
if (fc->isFree()) { |
|
1025 |
return fc->size(); |
|
1026 |
} else { |
|
1027 |
// Ignore mark word because this may be a recently promoted |
|
1028 |
// object whose mark word is used to chain together grey |
|
1029 |
// objects (the last one would have a null value). |
|
1030 |
assert(oop(p)->is_oop(true), "Should be an oop"); |
|
1031 |
return adjustObjectSize(oop(p)->size()); |
|
1032 |
} |
|
1033 |
} |
|
1034 |
||
1035 |
// This implementation assumes that the property of "being an object" is |
|
1036 |
// stable. But being a free chunk may not be (because of parallel |
|
1037 |
// promotion.) |
|
1038 |
bool CompactibleFreeListSpace::block_is_obj(const HeapWord* p) const { |
|
1039 |
FreeChunk* fc = (FreeChunk*)p; |
|
1040 |
assert(is_in_reserved(p), "Should be in space"); |
|
1041 |
// When doing a mark-sweep-compact of the CMS generation, this |
|
1042 |
// assertion may fail because prepare_for_compaction() uses |
|
1043 |
// space that is garbage to maintain information on ranges of |
|
1044 |
// live objects so that these live ranges can be moved as a whole. |
|
1045 |
// Comment out this assertion until that problem can be solved |
|
1046 |
// (i.e., that the block start calculation may look at objects |
|
1047 |
// at address below "p" in finding the object that contains "p" |
|
1048 |
// and those objects (if garbage) may have been modified to hold |
|
1049 |
// live range information. |
|
1050 |
// assert(ParallelGCThreads > 0 || _bt.block_start(p) == p, "Should be a block boundary"); |
|
613 | 1051 |
if (FreeChunk::indicatesFreeChunk(p)) return false; |
1052 |
klassOop k = oop(p)->klass_or_null(); |
|
1 | 1053 |
if (k != NULL) { |
1054 |
// Ignore mark word because it may have been used to |
|
1055 |
// chain together promoted objects (the last one |
|
1056 |
// would have a null value). |
|
1057 |
assert(oop(p)->is_oop(true), "Should be an oop"); |
|
1058 |
return true; |
|
1059 |
} else { |
|
1060 |
return false; // Was not an object at the start of collection. |
|
1061 |
} |
|
1062 |
} |
|
1063 |
||
1064 |
// Check if the object is alive. This fact is checked either by consulting |
|
1065 |
// the main marking bitmap in the sweeping phase or, if it's a permanent |
|
1066 |
// generation and we're not in the sweeping phase, by checking the |
|
1067 |
// perm_gen_verify_bit_map where we store the "deadness" information if |
|
1068 |
// we did not sweep the perm gen in the most recent previous GC cycle. |
|
1069 |
bool CompactibleFreeListSpace::obj_is_alive(const HeapWord* p) const { |
|
1070 |
assert (block_is_obj(p), "The address should point to an object"); |
|
1071 |
||
1072 |
// If we're sweeping, we use object liveness information from the main bit map |
|
1073 |
// for both perm gen and old gen. |
|
1074 |
// We don't need to lock the bitmap (live_map or dead_map below), because |
|
1075 |
// EITHER we are in the middle of the sweeping phase, and the |
|
1076 |
// main marking bit map (live_map below) is locked, |
|
1077 |
// OR we're in other phases and perm_gen_verify_bit_map (dead_map below) |
|
1078 |
// is stable, because it's mutated only in the sweeping phase. |
|
1079 |
if (_collector->abstract_state() == CMSCollector::Sweeping) { |
|
1080 |
CMSBitMap* live_map = _collector->markBitMap(); |
|
1081 |
return live_map->isMarked((HeapWord*) p); |
|
1082 |
} else { |
|
1083 |
// If we're not currently sweeping and we haven't swept the perm gen in |
|
1084 |
// the previous concurrent cycle then we may have dead but unswept objects |
|
1085 |
// in the perm gen. In this case, we use the "deadness" information |
|
1086 |
// that we had saved in perm_gen_verify_bit_map at the last sweep. |
|
1087 |
if (!CMSClassUnloadingEnabled && _collector->_permGen->reserved().contains(p)) { |
|
1088 |
if (_collector->verifying()) { |
|
1089 |
CMSBitMap* dead_map = _collector->perm_gen_verify_bit_map(); |
|
1090 |
// Object is marked in the dead_map bitmap at the previous sweep |
|
1091 |
// when we know that it's dead; if the bitmap is not allocated then |
|
1092 |
// the object is alive. |
|
1093 |
return (dead_map->sizeInBits() == 0) // bit_map has been allocated |
|
1094 |
|| !dead_map->par_isMarked((HeapWord*) p); |
|
1095 |
} else { |
|
1096 |
return false; // We can't say for sure if it's live, so we say that it's dead. |
|
1097 |
} |
|
1098 |
} |
|
1099 |
} |
|
1100 |
return true; |
|
1101 |
} |
|
1102 |
||
1103 |
bool CompactibleFreeListSpace::block_is_obj_nopar(const HeapWord* p) const { |
|
1104 |
FreeChunk* fc = (FreeChunk*)p; |
|
1105 |
assert(is_in_reserved(p), "Should be in space"); |
|
1106 |
assert(_bt.block_start(p) == p, "Should be a block boundary"); |
|
1107 |
if (!fc->isFree()) { |
|
1108 |
// Ignore mark word because it may have been used to |
|
1109 |
// chain together promoted objects (the last one |
|
1110 |
// would have a null value). |
|
1111 |
assert(oop(p)->is_oop(true), "Should be an oop"); |
|
1112 |
return true; |
|
1113 |
} |
|
1114 |
return false; |
|
1115 |
} |
|
1116 |
||
1117 |
// "MT-safe but not guaranteed MT-precise" (TM); you may get an |
|
1118 |
// approximate answer if you don't hold the freelistlock when you call this. |
|
1119 |
size_t CompactibleFreeListSpace::totalSizeInIndexedFreeLists() const { |
|
1120 |
size_t size = 0; |
|
1121 |
for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
|
1122 |
debug_only( |
|
1123 |
// We may be calling here without the lock in which case we |
|
1124 |
// won't do this modest sanity check. |
|
1125 |
if (freelistLock()->owned_by_self()) { |
|
1126 |
size_t total_list_size = 0; |
|
1127 |
for (FreeChunk* fc = _indexedFreeList[i].head(); fc != NULL; |
|
1128 |
fc = fc->next()) { |
|
1129 |
total_list_size += i; |
|
1130 |
} |
|
1131 |
assert(total_list_size == i * _indexedFreeList[i].count(), |
|
1132 |
"Count in list is incorrect"); |
|
1133 |
} |
|
1134 |
) |
|
1135 |
size += i * _indexedFreeList[i].count(); |
|
1136 |
} |
|
1137 |
return size; |
|
1138 |
} |
|
1139 |
||
1140 |
HeapWord* CompactibleFreeListSpace::par_allocate(size_t size) { |
|
1141 |
MutexLockerEx x(freelistLock(), Mutex::_no_safepoint_check_flag); |
|
1142 |
return allocate(size); |
|
1143 |
} |
|
1144 |
||
1145 |
HeapWord* |
|
1146 |
CompactibleFreeListSpace::getChunkFromSmallLinearAllocBlockRemainder(size_t size) { |
|
1147 |
return getChunkFromLinearAllocBlockRemainder(&_smallLinearAllocBlock, size); |
|
1148 |
} |
|
1149 |
||
1150 |
HeapWord* CompactibleFreeListSpace::allocate(size_t size) { |
|
1151 |
assert_lock_strong(freelistLock()); |
|
1152 |
HeapWord* res = NULL; |
|
1153 |
assert(size == adjustObjectSize(size), |
|
1154 |
"use adjustObjectSize() before calling into allocate()"); |
|
1155 |
||
1156 |
if (_adaptive_freelists) { |
|
1157 |
res = allocate_adaptive_freelists(size); |
|
1158 |
} else { // non-adaptive free lists |
|
1159 |
res = allocate_non_adaptive_freelists(size); |
|
1160 |
} |
|
1161 |
||
1162 |
if (res != NULL) { |
|
1163 |
// check that res does lie in this space! |
|
1164 |
assert(is_in_reserved(res), "Not in this space!"); |
|
1165 |
assert(is_aligned((void*)res), "alignment check"); |
|
1166 |
||
1167 |
FreeChunk* fc = (FreeChunk*)res; |
|
1168 |
fc->markNotFree(); |
|
1169 |
assert(!fc->isFree(), "shouldn't be marked free"); |
|
613 | 1170 |
assert(oop(fc)->klass_or_null() == NULL, "should look uninitialized"); |
1 | 1171 |
// Verify that the block offset table shows this to |
1172 |
// be a single block, but not one which is unallocated. |
|
1173 |
_bt.verify_single_block(res, size); |
|
1174 |
_bt.verify_not_unallocated(res, size); |
|
1175 |
// mangle a just allocated object with a distinct pattern. |
|
1176 |
debug_only(fc->mangleAllocated(size)); |
|
1177 |
} |
|
1178 |
||
1179 |
return res; |
|
1180 |
} |
|
1181 |
||
1182 |
HeapWord* CompactibleFreeListSpace::allocate_non_adaptive_freelists(size_t size) { |
|
1183 |
HeapWord* res = NULL; |
|
1184 |
// try and use linear allocation for smaller blocks |
|
1185 |
if (size < _smallLinearAllocBlock._allocation_size_limit) { |
|
1186 |
// if successful, the following also adjusts block offset table |
|
1187 |
res = getChunkFromSmallLinearAllocBlock(size); |
|
1188 |
} |
|
1189 |
// Else triage to indexed lists for smaller sizes |
|
1190 |
if (res == NULL) { |
|
1191 |
if (size < SmallForDictionary) { |
|
1192 |
res = (HeapWord*) getChunkFromIndexedFreeList(size); |
|
1193 |
} else { |
|
1194 |
// else get it from the big dictionary; if even this doesn't |
|
1195 |
// work we are out of luck. |
|
1196 |
res = (HeapWord*)getChunkFromDictionaryExact(size); |
|
1197 |
} |
|
1198 |
} |
|
1199 |
||
1200 |
return res; |
|
1201 |
} |
|
1202 |
||
1203 |
HeapWord* CompactibleFreeListSpace::allocate_adaptive_freelists(size_t size) { |
|
1204 |
assert_lock_strong(freelistLock()); |
|
1205 |
HeapWord* res = NULL; |
|
1206 |
assert(size == adjustObjectSize(size), |
|
1207 |
"use adjustObjectSize() before calling into allocate()"); |
|
1208 |
||
1209 |
// Strategy |
|
1210 |
// if small |
|
1211 |
// exact size from small object indexed list if small |
|
1212 |
// small or large linear allocation block (linAB) as appropriate |
|
1213 |
// take from lists of greater sized chunks |
|
1214 |
// else |
|
1215 |
// dictionary |
|
1216 |
// small or large linear allocation block if it has the space |
|
1217 |
// Try allocating exact size from indexTable first |
|
1218 |
if (size < IndexSetSize) { |
|
1219 |
res = (HeapWord*) getChunkFromIndexedFreeList(size); |
|
1220 |
if(res != NULL) { |
|
1221 |
assert(res != (HeapWord*)_indexedFreeList[size].head(), |
|
1222 |
"Not removed from free list"); |
|
1223 |
// no block offset table adjustment is necessary on blocks in |
|
1224 |
// the indexed lists. |
|
1225 |
||
1226 |
// Try allocating from the small LinAB |
|
1227 |
} else if (size < _smallLinearAllocBlock._allocation_size_limit && |
|
1228 |
(res = getChunkFromSmallLinearAllocBlock(size)) != NULL) { |
|
1229 |
// if successful, the above also adjusts block offset table |
|
1230 |
// Note that this call will refill the LinAB to |
|
1231 |
// satisfy the request. This is different that |
|
1232 |
// evm. |
|
1233 |
// Don't record chunk off a LinAB? smallSplitBirth(size); |
|
1234 |
||
1235 |
} else { |
|
1236 |
// Raid the exact free lists larger than size, even if they are not |
|
1237 |
// overpopulated. |
|
1238 |
res = (HeapWord*) getChunkFromGreater(size); |
|
1239 |
} |
|
1240 |
} else { |
|
1241 |
// Big objects get allocated directly from the dictionary. |
|
1242 |
res = (HeapWord*) getChunkFromDictionaryExact(size); |
|
1243 |
if (res == NULL) { |
|
1244 |
// Try hard not to fail since an allocation failure will likely |
|
1245 |
// trigger a synchronous GC. Try to get the space from the |
|
1246 |
// allocation blocks. |
|
1247 |
res = getChunkFromSmallLinearAllocBlockRemainder(size); |
|
1248 |
} |
|
1249 |
} |
|
1250 |
||
1251 |
return res; |
|
1252 |
} |
|
1253 |
||
1254 |
// A worst-case estimate of the space required (in HeapWords) to expand the heap |
|
1255 |
// when promoting obj. |
|
1256 |
size_t CompactibleFreeListSpace::expansionSpaceRequired(size_t obj_size) const { |
|
1257 |
// Depending on the object size, expansion may require refilling either a |
|
1258 |
// bigLAB or a smallLAB plus refilling a PromotionInfo object. MinChunkSize |
|
1259 |
// is added because the dictionary may over-allocate to avoid fragmentation. |
|
1260 |
size_t space = obj_size; |
|
1261 |
if (!_adaptive_freelists) { |
|
1262 |
space = MAX2(space, _smallLinearAllocBlock._refillSize); |
|
1263 |
} |
|
1264 |
space += _promoInfo.refillSize() + 2 * MinChunkSize; |
|
1265 |
return space; |
|
1266 |
} |
|
1267 |
||
1268 |
FreeChunk* CompactibleFreeListSpace::getChunkFromGreater(size_t numWords) { |
|
1269 |
FreeChunk* ret; |
|
1270 |
||
1271 |
assert(numWords >= MinChunkSize, "Size is less than minimum"); |
|
1272 |
assert(linearAllocationWouldFail() || bestFitFirst(), |
|
1273 |
"Should not be here"); |
|
1274 |
||
1275 |
size_t i; |
|
1276 |
size_t currSize = numWords + MinChunkSize; |
|
1277 |
assert(currSize % MinObjAlignment == 0, "currSize should be aligned"); |
|
1278 |
for (i = currSize; i < IndexSetSize; i += IndexSetStride) { |
|
1279 |
FreeList* fl = &_indexedFreeList[i]; |
|
1280 |
if (fl->head()) { |
|
1281 |
ret = getFromListGreater(fl, numWords); |
|
1282 |
assert(ret == NULL || ret->isFree(), "Should be returning a free chunk"); |
|
1283 |
return ret; |
|
1284 |
} |
|
1285 |
} |
|
1286 |
||
1287 |
currSize = MAX2((size_t)SmallForDictionary, |
|
1288 |
(size_t)(numWords + MinChunkSize)); |
|
1289 |
||
1290 |
/* Try to get a chunk that satisfies request, while avoiding |
|
1291 |
fragmentation that can't be handled. */ |
|
1292 |
{ |
|
1293 |
ret = dictionary()->getChunk(currSize); |
|
1294 |
if (ret != NULL) { |
|
1295 |
assert(ret->size() - numWords >= MinChunkSize, |
|
1296 |
"Chunk is too small"); |
|
1297 |
_bt.allocated((HeapWord*)ret, ret->size()); |
|
1298 |
/* Carve returned chunk. */ |
|
1299 |
(void) splitChunkAndReturnRemainder(ret, numWords); |
|
1300 |
/* Label this as no longer a free chunk. */ |
|
1301 |
assert(ret->isFree(), "This chunk should be free"); |
|
1302 |
ret->linkPrev(NULL); |
|
1303 |
} |
|
1304 |
assert(ret == NULL || ret->isFree(), "Should be returning a free chunk"); |
|
1305 |
return ret; |
|
1306 |
} |
|
1307 |
ShouldNotReachHere(); |
|
1308 |
} |
|
1309 |
||
1310 |
bool CompactibleFreeListSpace::verifyChunkInIndexedFreeLists(FreeChunk* fc) |
|
1311 |
const { |
|
1312 |
assert(fc->size() < IndexSetSize, "Size of chunk is too large"); |
|
1313 |
return _indexedFreeList[fc->size()].verifyChunkInFreeLists(fc); |
|
1314 |
} |
|
1315 |
||
1316 |
bool CompactibleFreeListSpace::verifyChunkInFreeLists(FreeChunk* fc) const { |
|
1317 |
if (fc->size() >= IndexSetSize) { |
|
1318 |
return dictionary()->verifyChunkInFreeLists(fc); |
|
1319 |
} else { |
|
1320 |
return verifyChunkInIndexedFreeLists(fc); |
|
1321 |
} |
|
1322 |
} |
|
1323 |
||
1324 |
#ifndef PRODUCT |
|
1325 |
void CompactibleFreeListSpace::assert_locked() const { |
|
1326 |
CMSLockVerifier::assert_locked(freelistLock(), parDictionaryAllocLock()); |
|
1327 |
} |
|
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1328 |
|
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|
1329 |
void CompactibleFreeListSpace::assert_locked(const Mutex* lock) const { |
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|
1330 |
CMSLockVerifier::assert_locked(lock); |
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|
1331 |
} |
1 | 1332 |
#endif |
1333 |
||
1334 |
FreeChunk* CompactibleFreeListSpace::allocateScratch(size_t size) { |
|
1335 |
// In the parallel case, the main thread holds the free list lock |
|
1336 |
// on behalf the parallel threads. |
|
1337 |
FreeChunk* fc; |
|
1338 |
{ |
|
1339 |
// If GC is parallel, this might be called by several threads. |
|
1340 |
// This should be rare enough that the locking overhead won't affect |
|
1341 |
// the sequential code. |
|
1342 |
MutexLockerEx x(parDictionaryAllocLock(), |
|
1343 |
Mutex::_no_safepoint_check_flag); |
|
1344 |
fc = getChunkFromDictionary(size); |
|
1345 |
} |
|
1346 |
if (fc != NULL) { |
|
1347 |
fc->dontCoalesce(); |
|
1348 |
assert(fc->isFree(), "Should be free, but not coalescable"); |
|
1349 |
// Verify that the block offset table shows this to |
|
1350 |
// be a single block, but not one which is unallocated. |
|
1351 |
_bt.verify_single_block((HeapWord*)fc, fc->size()); |
|
1352 |
_bt.verify_not_unallocated((HeapWord*)fc, fc->size()); |
|
1353 |
} |
|
1354 |
return fc; |
|
1355 |
} |
|
1356 |
||
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|
1357 |
oop CompactibleFreeListSpace::promote(oop obj, size_t obj_size) { |
1 | 1358 |
assert(obj_size == (size_t)obj->size(), "bad obj_size passed in"); |
1359 |
assert_locked(); |
|
1360 |
||
1361 |
// if we are tracking promotions, then first ensure space for |
|
1362 |
// promotion (including spooling space for saving header if necessary). |
|
1363 |
// then allocate and copy, then track promoted info if needed. |
|
1364 |
// When tracking (see PromotionInfo::track()), the mark word may |
|
1365 |
// be displaced and in this case restoration of the mark word |
|
1366 |
// occurs in the (oop_since_save_marks_)iterate phase. |
|
1367 |
if (_promoInfo.tracking() && !_promoInfo.ensure_spooling_space()) { |
|
1368 |
return NULL; |
|
1369 |
} |
|
1370 |
// Call the allocate(size_t, bool) form directly to avoid the |
|
1371 |
// additional call through the allocate(size_t) form. Having |
|
1372 |
// the compile inline the call is problematic because allocate(size_t) |
|
1373 |
// is a virtual method. |
|
1374 |
HeapWord* res = allocate(adjustObjectSize(obj_size)); |
|
1375 |
if (res != NULL) { |
|
1376 |
Copy::aligned_disjoint_words((HeapWord*)obj, res, obj_size); |
|
1377 |
// if we should be tracking promotions, do so. |
|
1378 |
if (_promoInfo.tracking()) { |
|
1379 |
_promoInfo.track((PromotedObject*)res); |
|
1380 |
} |
|
1381 |
} |
|
1382 |
return oop(res); |
|
1383 |
} |
|
1384 |
||
1385 |
HeapWord* |
|
1386 |
CompactibleFreeListSpace::getChunkFromSmallLinearAllocBlock(size_t size) { |
|
1387 |
assert_locked(); |
|
1388 |
assert(size >= MinChunkSize, "minimum chunk size"); |
|
1389 |
assert(size < _smallLinearAllocBlock._allocation_size_limit, |
|
1390 |
"maximum from smallLinearAllocBlock"); |
|
1391 |
return getChunkFromLinearAllocBlock(&_smallLinearAllocBlock, size); |
|
1392 |
} |
|
1393 |
||
1394 |
HeapWord* |
|
1395 |
CompactibleFreeListSpace::getChunkFromLinearAllocBlock(LinearAllocBlock *blk, |
|
1396 |
size_t size) { |
|
1397 |
assert_locked(); |
|
1398 |
assert(size >= MinChunkSize, "too small"); |
|
1399 |
HeapWord* res = NULL; |
|
1400 |
// Try to do linear allocation from blk, making sure that |
|
1401 |
if (blk->_word_size == 0) { |
|
1402 |
// We have probably been unable to fill this either in the prologue or |
|
1403 |
// when it was exhausted at the last linear allocation. Bail out until |
|
1404 |
// next time. |
|
1405 |
assert(blk->_ptr == NULL, "consistency check"); |
|
1406 |
return NULL; |
|
1407 |
} |
|
1408 |
assert(blk->_word_size != 0 && blk->_ptr != NULL, "consistency check"); |
|
1409 |
res = getChunkFromLinearAllocBlockRemainder(blk, size); |
|
1410 |
if (res != NULL) return res; |
|
1411 |
||
1412 |
// about to exhaust this linear allocation block |
|
1413 |
if (blk->_word_size == size) { // exactly satisfied |
|
1414 |
res = blk->_ptr; |
|
1415 |
_bt.allocated(res, blk->_word_size); |
|
1416 |
} else if (size + MinChunkSize <= blk->_refillSize) { |
|
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|
1417 |
size_t sz = blk->_word_size; |
1 | 1418 |
// Update _unallocated_block if the size is such that chunk would be |
1419 |
// returned to the indexed free list. All other chunks in the indexed |
|
1420 |
// free lists are allocated from the dictionary so that _unallocated_block |
|
1421 |
// has already been adjusted for them. Do it here so that the cost |
|
1422 |
// for all chunks added back to the indexed free lists. |
|
4574
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|
1423 |
if (sz < SmallForDictionary) { |
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|
1424 |
_bt.allocated(blk->_ptr, sz); |
1 | 1425 |
} |
1426 |
// Return the chunk that isn't big enough, and then refill below. |
|
4574
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|
1427 |
addChunkToFreeLists(blk->_ptr, sz); |
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|
1428 |
splitBirth(sz); |
1 | 1429 |
// Don't keep statistics on adding back chunk from a LinAB. |
1430 |
} else { |
|
1431 |
// A refilled block would not satisfy the request. |
|
1432 |
return NULL; |
|
1433 |
} |
|
1434 |
||
1435 |
blk->_ptr = NULL; blk->_word_size = 0; |
|
1436 |
refillLinearAllocBlock(blk); |
|
1437 |
assert(blk->_ptr == NULL || blk->_word_size >= size + MinChunkSize, |
|
1438 |
"block was replenished"); |
|
1439 |
if (res != NULL) { |
|
1440 |
splitBirth(size); |
|
1441 |
repairLinearAllocBlock(blk); |
|
1442 |
} else if (blk->_ptr != NULL) { |
|
1443 |
res = blk->_ptr; |
|
1444 |
size_t blk_size = blk->_word_size; |
|
1445 |
blk->_word_size -= size; |
|
1446 |
blk->_ptr += size; |
|
1447 |
splitBirth(size); |
|
1448 |
repairLinearAllocBlock(blk); |
|
1449 |
// Update BOT last so that other (parallel) GC threads see a consistent |
|
1450 |
// view of the BOT and free blocks. |
|
1451 |
// Above must occur before BOT is updated below. |
|
1452 |
_bt.split_block(res, blk_size, size); // adjust block offset table |
|
1453 |
} |
|
1454 |
return res; |
|
1455 |
} |
|
1456 |
||
1457 |
HeapWord* CompactibleFreeListSpace::getChunkFromLinearAllocBlockRemainder( |
|
1458 |
LinearAllocBlock* blk, |
|
1459 |
size_t size) { |
|
1460 |
assert_locked(); |
|
1461 |
assert(size >= MinChunkSize, "too small"); |
|
1462 |
||
1463 |
HeapWord* res = NULL; |
|
1464 |
// This is the common case. Keep it simple. |
|
1465 |
if (blk->_word_size >= size + MinChunkSize) { |
|
1466 |
assert(blk->_ptr != NULL, "consistency check"); |
|
1467 |
res = blk->_ptr; |
|
1468 |
// Note that the BOT is up-to-date for the linAB before allocation. It |
|
1469 |
// indicates the start of the linAB. The split_block() updates the |
|
1470 |
// BOT for the linAB after the allocation (indicates the start of the |
|
1471 |
// next chunk to be allocated). |
|
1472 |
size_t blk_size = blk->_word_size; |
|
1473 |
blk->_word_size -= size; |
|
1474 |
blk->_ptr += size; |
|
1475 |
splitBirth(size); |
|
1476 |
repairLinearAllocBlock(blk); |
|
1477 |
// Update BOT last so that other (parallel) GC threads see a consistent |
|
1478 |
// view of the BOT and free blocks. |
|
1479 |
// Above must occur before BOT is updated below. |
|
1480 |
_bt.split_block(res, blk_size, size); // adjust block offset table |
|
1481 |
_bt.allocated(res, size); |
|
1482 |
} |
|
1483 |
return res; |
|
1484 |
} |
|
1485 |
||
1486 |
FreeChunk* |
|
1487 |
CompactibleFreeListSpace::getChunkFromIndexedFreeList(size_t size) { |
|
1488 |
assert_locked(); |
|
1489 |
assert(size < SmallForDictionary, "just checking"); |
|
1490 |
FreeChunk* res; |
|
1491 |
res = _indexedFreeList[size].getChunkAtHead(); |
|
1492 |
if (res == NULL) { |
|
1493 |
res = getChunkFromIndexedFreeListHelper(size); |
|
1494 |
} |
|
1495 |
_bt.verify_not_unallocated((HeapWord*) res, size); |
|
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|
1496 |
assert(res == NULL || res->size() == size, "Incorrect block size"); |
1 | 1497 |
return res; |
1498 |
} |
|
1499 |
||
1500 |
FreeChunk* |
|
4574
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|
1501 |
CompactibleFreeListSpace::getChunkFromIndexedFreeListHelper(size_t size, |
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|
1502 |
bool replenish) { |
1 | 1503 |
assert_locked(); |
1504 |
FreeChunk* fc = NULL; |
|
1505 |
if (size < SmallForDictionary) { |
|
1506 |
assert(_indexedFreeList[size].head() == NULL || |
|
1507 |
_indexedFreeList[size].surplus() <= 0, |
|
1508 |
"List for this size should be empty or under populated"); |
|
1509 |
// Try best fit in exact lists before replenishing the list |
|
1510 |
if (!bestFitFirst() || (fc = bestFitSmall(size)) == NULL) { |
|
1511 |
// Replenish list. |
|
1512 |
// |
|
1513 |
// Things tried that failed. |
|
1514 |
// Tried allocating out of the two LinAB's first before |
|
1515 |
// replenishing lists. |
|
1516 |
// Tried small linAB of size 256 (size in indexed list) |
|
1517 |
// and replenishing indexed lists from the small linAB. |
|
1518 |
// |
|
1519 |
FreeChunk* newFc = NULL; |
|
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|
1520 |
const size_t replenish_size = CMSIndexedFreeListReplenish * size; |
1 | 1521 |
if (replenish_size < SmallForDictionary) { |
1522 |
// Do not replenish from an underpopulated size. |
|
1523 |
if (_indexedFreeList[replenish_size].surplus() > 0 && |
|
1524 |
_indexedFreeList[replenish_size].head() != NULL) { |
|
4574
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|
1525 |
newFc = _indexedFreeList[replenish_size].getChunkAtHead(); |
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|
1526 |
} else if (bestFitFirst()) { |
1 | 1527 |
newFc = bestFitSmall(replenish_size); |
1528 |
} |
|
1529 |
} |
|
4574
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|
1530 |
if (newFc == NULL && replenish_size > size) { |
1 | 1531 |
assert(CMSIndexedFreeListReplenish > 1, "ctl pt invariant"); |
4574
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|
1532 |
newFc = getChunkFromIndexedFreeListHelper(replenish_size, false); |
1 | 1533 |
} |
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|
1534 |
// Note: The stats update re split-death of block obtained above |
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|
1535 |
// will be recorded below precisely when we know we are going to |
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|
1536 |
// be actually splitting it into more than one pieces below. |
1 | 1537 |
if (newFc != NULL) { |
4574
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|
1538 |
if (replenish || CMSReplenishIntermediate) { |
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|
1539 |
// Replenish this list and return one block to caller. |
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|
1540 |
size_t i; |
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|
1541 |
FreeChunk *curFc, *nextFc; |
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|
1542 |
size_t num_blk = newFc->size() / size; |
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|
1543 |
assert(num_blk >= 1, "Smaller than requested?"); |
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|
1544 |
assert(newFc->size() % size == 0, "Should be integral multiple of request"); |
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|
1545 |
if (num_blk > 1) { |
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|
1546 |
// we are sure we will be splitting the block just obtained |
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|
1547 |
// into multiple pieces; record the split-death of the original |
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|
1548 |
splitDeath(replenish_size); |
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|
1549 |
} |
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|
1550 |
// carve up and link blocks 0, ..., num_blk - 2 |
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|
1551 |
// The last chunk is not added to the lists but is returned as the |
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|
1552 |
// free chunk. |
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|
1553 |
for (curFc = newFc, nextFc = (FreeChunk*)((HeapWord*)curFc + size), |
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|
1554 |
i = 0; |
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|
1555 |
i < (num_blk - 1); |
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|
1556 |
curFc = nextFc, nextFc = (FreeChunk*)((HeapWord*)nextFc + size), |
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|
1557 |
i++) { |
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|
1558 |
curFc->setSize(size); |
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changeset
|
1559 |
// Don't record this as a return in order to try and |
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|
1560 |
// determine the "returns" from a GC. |
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|
1561 |
_bt.verify_not_unallocated((HeapWord*) fc, size); |
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|
1562 |
_indexedFreeList[size].returnChunkAtTail(curFc, false); |
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|
1563 |
_bt.mark_block((HeapWord*)curFc, size); |
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|
1564 |
splitBirth(size); |
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|
1565 |
// Don't record the initial population of the indexed list |
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|
1566 |
// as a split birth. |
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|
1567 |
} |
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|
1568 |
|
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|
1569 |
// check that the arithmetic was OK above |
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changeset
|
1570 |
assert((HeapWord*)nextFc == (HeapWord*)newFc + num_blk*size, |
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changeset
|
1571 |
"inconsistency in carving newFc"); |
1 | 1572 |
curFc->setSize(size); |
1573 |
_bt.mark_block((HeapWord*)curFc, size); |
|
1574 |
splitBirth(size); |
|
4574
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|
1575 |
fc = curFc; |
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|
1576 |
} else { |
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|
1577 |
// Return entire block to caller |
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changeset
|
1578 |
fc = newFc; |
1 | 1579 |
} |
1580 |
} |
|
1581 |
} |
|
1582 |
} else { |
|
1583 |
// Get a free chunk from the free chunk dictionary to be returned to |
|
1584 |
// replenish the indexed free list. |
|
1585 |
fc = getChunkFromDictionaryExact(size); |
|
1586 |
} |
|
4574
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|
1587 |
// assert(fc == NULL || fc->isFree(), "Should be returning a free chunk"); |
1 | 1588 |
return fc; |
1589 |
} |
|
1590 |
||
1591 |
FreeChunk* |
|
1592 |
CompactibleFreeListSpace::getChunkFromDictionary(size_t size) { |
|
1593 |
assert_locked(); |
|
1594 |
FreeChunk* fc = _dictionary->getChunk(size); |
|
1595 |
if (fc == NULL) { |
|
1596 |
return NULL; |
|
1597 |
} |
|
1598 |
_bt.allocated((HeapWord*)fc, fc->size()); |
|
1599 |
if (fc->size() >= size + MinChunkSize) { |
|
1600 |
fc = splitChunkAndReturnRemainder(fc, size); |
|
1601 |
} |
|
1602 |
assert(fc->size() >= size, "chunk too small"); |
|
1603 |
assert(fc->size() < size + MinChunkSize, "chunk too big"); |
|
1604 |
_bt.verify_single_block((HeapWord*)fc, fc->size()); |
|
1605 |
return fc; |
|
1606 |
} |
|
1607 |
||
1608 |
FreeChunk* |
|
1609 |
CompactibleFreeListSpace::getChunkFromDictionaryExact(size_t size) { |
|
1610 |
assert_locked(); |
|
1611 |
FreeChunk* fc = _dictionary->getChunk(size); |
|
1612 |
if (fc == NULL) { |
|
1613 |
return fc; |
|
1614 |
} |
|
1615 |
_bt.allocated((HeapWord*)fc, fc->size()); |
|
1616 |
if (fc->size() == size) { |
|
1617 |
_bt.verify_single_block((HeapWord*)fc, size); |
|
1618 |
return fc; |
|
1619 |
} |
|
1620 |
assert(fc->size() > size, "getChunk() guarantee"); |
|
1621 |
if (fc->size() < size + MinChunkSize) { |
|
1622 |
// Return the chunk to the dictionary and go get a bigger one. |
|
1623 |
returnChunkToDictionary(fc); |
|
1624 |
fc = _dictionary->getChunk(size + MinChunkSize); |
|
1625 |
if (fc == NULL) { |
|
1626 |
return NULL; |
|
1627 |
} |
|
1628 |
_bt.allocated((HeapWord*)fc, fc->size()); |
|
1629 |
} |
|
1630 |
assert(fc->size() >= size + MinChunkSize, "tautology"); |
|
1631 |
fc = splitChunkAndReturnRemainder(fc, size); |
|
1632 |
assert(fc->size() == size, "chunk is wrong size"); |
|
1633 |
_bt.verify_single_block((HeapWord*)fc, size); |
|
1634 |
return fc; |
|
1635 |
} |
|
1636 |
||
1637 |
void |
|
1638 |
CompactibleFreeListSpace::returnChunkToDictionary(FreeChunk* chunk) { |
|
1639 |
assert_locked(); |
|
1640 |
||
1641 |
size_t size = chunk->size(); |
|
1642 |
_bt.verify_single_block((HeapWord*)chunk, size); |
|
1643 |
// adjust _unallocated_block downward, as necessary |
|
1644 |
_bt.freed((HeapWord*)chunk, size); |
|
1645 |
_dictionary->returnChunk(chunk); |
|
4574
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|
1646 |
#ifndef PRODUCT |
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|
1647 |
if (CMSCollector::abstract_state() != CMSCollector::Sweeping) { |
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|
1648 |
TreeChunk::as_TreeChunk(chunk)->list()->verify_stats(); |
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|
1649 |
} |
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|
1650 |
#endif // PRODUCT |
1 | 1651 |
} |
1652 |
||
1653 |
void |
|
1654 |
CompactibleFreeListSpace::returnChunkToFreeList(FreeChunk* fc) { |
|
1655 |
assert_locked(); |
|
1656 |
size_t size = fc->size(); |
|
1657 |
_bt.verify_single_block((HeapWord*) fc, size); |
|
1658 |
_bt.verify_not_unallocated((HeapWord*) fc, size); |
|
1659 |
if (_adaptive_freelists) { |
|
1660 |
_indexedFreeList[size].returnChunkAtTail(fc); |
|
1661 |
} else { |
|
1662 |
_indexedFreeList[size].returnChunkAtHead(fc); |
|
1663 |
} |
|
4574
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|
1664 |
#ifndef PRODUCT |
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|
1665 |
if (CMSCollector::abstract_state() != CMSCollector::Sweeping) { |
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|
1666 |
_indexedFreeList[size].verify_stats(); |
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|
1667 |
} |
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|
1668 |
#endif // PRODUCT |
1 | 1669 |
} |
1670 |
||
1671 |
// Add chunk to end of last block -- if it's the largest |
|
1672 |
// block -- and update BOT and census data. We would |
|
1673 |
// of course have preferred to coalesce it with the |
|
1674 |
// last block, but it's currently less expensive to find the |
|
1675 |
// largest block than it is to find the last. |
|
1676 |
void |
|
1677 |
CompactibleFreeListSpace::addChunkToFreeListsAtEndRecordingStats( |
|
1678 |
HeapWord* chunk, size_t size) { |
|
1679 |
// check that the chunk does lie in this space! |
|
1680 |
assert(chunk != NULL && is_in_reserved(chunk), "Not in this space!"); |
|
1681 |
// One of the parallel gc task threads may be here |
|
1682 |
// whilst others are allocating. |
|
1683 |
Mutex* lock = NULL; |
|
1684 |
if (ParallelGCThreads != 0) { |
|
1685 |
lock = &_parDictionaryAllocLock; |
|
1686 |
} |
|
1687 |
FreeChunk* ec; |
|
1688 |
{ |
|
1689 |
MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag); |
|
1690 |
ec = dictionary()->findLargestDict(); // get largest block |
|
1691 |
if (ec != NULL && ec->end() == chunk) { |
|
1692 |
// It's a coterminal block - we can coalesce. |
|
1693 |
size_t old_size = ec->size(); |
|
1694 |
coalDeath(old_size); |
|
1695 |
removeChunkFromDictionary(ec); |
|
1696 |
size += old_size; |
|
1697 |
} else { |
|
1698 |
ec = (FreeChunk*)chunk; |
|
1699 |
} |
|
1700 |
} |
|
1701 |
ec->setSize(size); |
|
1702 |
debug_only(ec->mangleFreed(size)); |
|
1703 |
if (size < SmallForDictionary) { |
|
1704 |
lock = _indexedFreeListParLocks[size]; |
|
1705 |
} |
|
1706 |
MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag); |
|
1707 |
addChunkAndRepairOffsetTable((HeapWord*)ec, size, true); |
|
1708 |
// record the birth under the lock since the recording involves |
|
1709 |
// manipulation of the list on which the chunk lives and |
|
1710 |
// if the chunk is allocated and is the last on the list, |
|
1711 |
// the list can go away. |
|
1712 |
coalBirth(size); |
|
1713 |
} |
|
1714 |
||
1715 |
void |
|
1716 |
CompactibleFreeListSpace::addChunkToFreeLists(HeapWord* chunk, |
|
1717 |
size_t size) { |
|
1718 |
// check that the chunk does lie in this space! |
|
1719 |
assert(chunk != NULL && is_in_reserved(chunk), "Not in this space!"); |
|
1720 |
assert_locked(); |
|
1721 |
_bt.verify_single_block(chunk, size); |
|
1722 |
||
1723 |
FreeChunk* fc = (FreeChunk*) chunk; |
|
1724 |
fc->setSize(size); |
|
1725 |
debug_only(fc->mangleFreed(size)); |
|
1726 |
if (size < SmallForDictionary) { |
|
1727 |
returnChunkToFreeList(fc); |
|
1728 |
} else { |
|
1729 |
returnChunkToDictionary(fc); |
|
1730 |
} |
|
1731 |
} |
|
1732 |
||
1733 |
void |
|
1734 |
CompactibleFreeListSpace::addChunkAndRepairOffsetTable(HeapWord* chunk, |
|
1735 |
size_t size, bool coalesced) { |
|
1736 |
assert_locked(); |
|
1737 |
assert(chunk != NULL, "null chunk"); |
|
1738 |
if (coalesced) { |
|
1739 |
// repair BOT |
|
1740 |
_bt.single_block(chunk, size); |
|
1741 |
} |
|
1742 |
addChunkToFreeLists(chunk, size); |
|
1743 |
} |
|
1744 |
||
1745 |
// We _must_ find the purported chunk on our free lists; |
|
1746 |
// we assert if we don't. |
|
1747 |
void |
|
1748 |
CompactibleFreeListSpace::removeFreeChunkFromFreeLists(FreeChunk* fc) { |
|
1749 |
size_t size = fc->size(); |
|
1750 |
assert_locked(); |
|
1751 |
debug_only(verifyFreeLists()); |
|
1752 |
if (size < SmallForDictionary) { |
|
1753 |
removeChunkFromIndexedFreeList(fc); |
|
1754 |
} else { |
|
1755 |
removeChunkFromDictionary(fc); |
|
1756 |
} |
|
1757 |
_bt.verify_single_block((HeapWord*)fc, size); |
|
1758 |
debug_only(verifyFreeLists()); |
|
1759 |
} |
|
1760 |
||
1761 |
void |
|
1762 |
CompactibleFreeListSpace::removeChunkFromDictionary(FreeChunk* fc) { |
|
1763 |
size_t size = fc->size(); |
|
1764 |
assert_locked(); |
|
1765 |
assert(fc != NULL, "null chunk"); |
|
1766 |
_bt.verify_single_block((HeapWord*)fc, size); |
|
1767 |
_dictionary->removeChunk(fc); |
|
1768 |
// adjust _unallocated_block upward, as necessary |
|
1769 |
_bt.allocated((HeapWord*)fc, size); |
|
1770 |
} |
|
1771 |
||
1772 |
void |
|
1773 |
CompactibleFreeListSpace::removeChunkFromIndexedFreeList(FreeChunk* fc) { |
|
1774 |
assert_locked(); |
|
1775 |
size_t size = fc->size(); |
|
1776 |
_bt.verify_single_block((HeapWord*)fc, size); |
|
1777 |
NOT_PRODUCT( |
|
1778 |
if (FLSVerifyIndexTable) { |
|
1779 |
verifyIndexedFreeList(size); |
|
1780 |
} |
|
1781 |
) |
|
1782 |
_indexedFreeList[size].removeChunk(fc); |
|
1783 |
debug_only(fc->clearNext()); |
|
1784 |
debug_only(fc->clearPrev()); |
|
1785 |
NOT_PRODUCT( |
|
1786 |
if (FLSVerifyIndexTable) { |
|
1787 |
verifyIndexedFreeList(size); |
|
1788 |
} |
|
1789 |
) |
|
1790 |
} |
|
1791 |
||
1792 |
FreeChunk* CompactibleFreeListSpace::bestFitSmall(size_t numWords) { |
|
1793 |
/* A hint is the next larger size that has a surplus. |
|
1794 |
Start search at a size large enough to guarantee that |
|
1795 |
the excess is >= MIN_CHUNK. */ |
|
1796 |
size_t start = align_object_size(numWords + MinChunkSize); |
|
1797 |
if (start < IndexSetSize) { |
|
1798 |
FreeList* it = _indexedFreeList; |
|
1799 |
size_t hint = _indexedFreeList[start].hint(); |
|
1800 |
while (hint < IndexSetSize) { |
|
1801 |
assert(hint % MinObjAlignment == 0, "hint should be aligned"); |
|
1802 |
FreeList *fl = &_indexedFreeList[hint]; |
|
1803 |
if (fl->surplus() > 0 && fl->head() != NULL) { |
|
1804 |
// Found a list with surplus, reset original hint |
|
1805 |
// and split out a free chunk which is returned. |
|
1806 |
_indexedFreeList[start].set_hint(hint); |
|
1807 |
FreeChunk* res = getFromListGreater(fl, numWords); |
|
1808 |
assert(res == NULL || res->isFree(), |
|
1809 |
"Should be returning a free chunk"); |
|
1810 |
return res; |
|
1811 |
} |
|
1812 |
hint = fl->hint(); /* keep looking */ |
|
1813 |
} |
|
1814 |
/* None found. */ |
|
1815 |
it[start].set_hint(IndexSetSize); |
|
1816 |
} |
|
1817 |
return NULL; |
|
1818 |
} |
|
1819 |
||
1820 |
/* Requires fl->size >= numWords + MinChunkSize */ |
|
1821 |
FreeChunk* CompactibleFreeListSpace::getFromListGreater(FreeList* fl, |
|
1822 |
size_t numWords) { |
|
1823 |
FreeChunk *curr = fl->head(); |
|
1824 |
size_t oldNumWords = curr->size(); |
|
1825 |
assert(numWords >= MinChunkSize, "Word size is too small"); |
|
1826 |
assert(curr != NULL, "List is empty"); |
|
1827 |
assert(oldNumWords >= numWords + MinChunkSize, |
|
1828 |
"Size of chunks in the list is too small"); |
|
1829 |
||
1830 |
fl->removeChunk(curr); |
|
1831 |
// recorded indirectly by splitChunkAndReturnRemainder - |
|
1832 |
// smallSplit(oldNumWords, numWords); |
|
1833 |
FreeChunk* new_chunk = splitChunkAndReturnRemainder(curr, numWords); |
|
1834 |
// Does anything have to be done for the remainder in terms of |
|
1835 |
// fixing the card table? |
|
1836 |
assert(new_chunk == NULL || new_chunk->isFree(), |
|
1837 |
"Should be returning a free chunk"); |
|
1838 |
return new_chunk; |
|
1839 |
} |
|
1840 |
||
1841 |
FreeChunk* |
|
1842 |
CompactibleFreeListSpace::splitChunkAndReturnRemainder(FreeChunk* chunk, |
|
1843 |
size_t new_size) { |
|
1844 |
assert_locked(); |
|
1845 |
size_t size = chunk->size(); |
|
1846 |
assert(size > new_size, "Split from a smaller block?"); |
|
1847 |
assert(is_aligned(chunk), "alignment problem"); |
|
1848 |
assert(size == adjustObjectSize(size), "alignment problem"); |
|
1849 |
size_t rem_size = size - new_size; |
|
1850 |
assert(rem_size == adjustObjectSize(rem_size), "alignment problem"); |
|
1851 |
assert(rem_size >= MinChunkSize, "Free chunk smaller than minimum"); |
|
1852 |
FreeChunk* ffc = (FreeChunk*)((HeapWord*)chunk + new_size); |
|
1853 |
assert(is_aligned(ffc), "alignment problem"); |
|
1854 |
ffc->setSize(rem_size); |
|
1855 |
ffc->linkNext(NULL); |
|
1856 |
ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
|
1857 |
// Above must occur before BOT is updated below. |
|
1858 |
// adjust block offset table |
|
1859 |
_bt.split_block((HeapWord*)chunk, chunk->size(), new_size); |
|
1860 |
if (rem_size < SmallForDictionary) { |
|
1861 |
bool is_par = (SharedHeap::heap()->n_par_threads() > 0); |
|
1862 |
if (is_par) _indexedFreeListParLocks[rem_size]->lock(); |
|
1863 |
returnChunkToFreeList(ffc); |
|
1864 |
split(size, rem_size); |
|
1865 |
if (is_par) _indexedFreeListParLocks[rem_size]->unlock(); |
|
1866 |
} else { |
|
1867 |
returnChunkToDictionary(ffc); |
|
1868 |
split(size ,rem_size); |
|
1869 |
} |
|
1870 |
chunk->setSize(new_size); |
|
1871 |
return chunk; |
|
1872 |
} |
|
1873 |
||
1874 |
void |
|
1875 |
CompactibleFreeListSpace::sweep_completed() { |
|
1876 |
// Now that space is probably plentiful, refill linear |
|
1877 |
// allocation blocks as needed. |
|
1878 |
refillLinearAllocBlocksIfNeeded(); |
|
1879 |
} |
|
1880 |
||
1881 |
void |
|
1882 |
CompactibleFreeListSpace::gc_prologue() { |
|
1883 |
assert_locked(); |
|
1884 |
if (PrintFLSStatistics != 0) { |
|
1885 |
gclog_or_tty->print("Before GC:\n"); |
|
1886 |
reportFreeListStatistics(); |
|
1887 |
} |
|
1888 |
refillLinearAllocBlocksIfNeeded(); |
|
1889 |
} |
|
1890 |
||
1891 |
void |
|
1892 |
CompactibleFreeListSpace::gc_epilogue() { |
|
1893 |
assert_locked(); |
|
1894 |
if (PrintGCDetails && Verbose && !_adaptive_freelists) { |
|
1895 |
if (_smallLinearAllocBlock._word_size == 0) |
|
1896 |
warning("CompactibleFreeListSpace(epilogue):: Linear allocation failure"); |
|
1897 |
} |
|
1898 |
assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); |
|
1899 |
_promoInfo.stopTrackingPromotions(); |
|
1900 |
repairLinearAllocationBlocks(); |
|
1901 |
// Print Space's stats |
|
1902 |
if (PrintFLSStatistics != 0) { |
|
1903 |
gclog_or_tty->print("After GC:\n"); |
|
1904 |
reportFreeListStatistics(); |
|
1905 |
} |
|
1906 |
} |
|
1907 |
||
1908 |
// Iteration support, mostly delegated from a CMS generation |
|
1909 |
||
1910 |
void CompactibleFreeListSpace::save_marks() { |
|
1911 |
// mark the "end" of the used space at the time of this call; |
|
1912 |
// note, however, that promoted objects from this point |
|
1913 |
// on are tracked in the _promoInfo below. |
|
1914 |
set_saved_mark_word(BlockOffsetArrayUseUnallocatedBlock ? |
|
1915 |
unallocated_block() : end()); |
|
1916 |
// inform allocator that promotions should be tracked. |
|
1917 |
assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); |
|
1918 |
_promoInfo.startTrackingPromotions(); |
|
1919 |
} |
|
1920 |
||
1921 |
bool CompactibleFreeListSpace::no_allocs_since_save_marks() { |
|
1922 |
assert(_promoInfo.tracking(), "No preceding save_marks?"); |
|
1923 |
guarantee(SharedHeap::heap()->n_par_threads() == 0, |
|
1924 |
"Shouldn't be called (yet) during parallel part of gc."); |
|
1925 |
return _promoInfo.noPromotions(); |
|
1926 |
} |
|
1927 |
||
1928 |
#define CFLS_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \ |
|
1929 |
\ |
|
1930 |
void CompactibleFreeListSpace:: \ |
|
1931 |
oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) { \ |
|
1932 |
assert(SharedHeap::heap()->n_par_threads() == 0, \ |
|
1933 |
"Shouldn't be called (yet) during parallel part of gc."); \ |
|
1934 |
_promoInfo.promoted_oops_iterate##nv_suffix(blk); \ |
|
1935 |
/* \ |
|
1936 |
* This also restores any displaced headers and removes the elements from \ |
|
1937 |
* the iteration set as they are processed, so that we have a clean slate \ |
|
1938 |
* at the end of the iteration. Note, thus, that if new objects are \ |
|
1939 |
* promoted as a result of the iteration they are iterated over as well. \ |
|
1940 |
*/ \ |
|
1941 |
assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); \ |
|
1942 |
} |
|
1943 |
||
1944 |
ALL_SINCE_SAVE_MARKS_CLOSURES(CFLS_OOP_SINCE_SAVE_MARKS_DEFN) |
|
1945 |
||
1946 |
||
1947 |
void CompactibleFreeListSpace::object_iterate_since_last_GC(ObjectClosure* cl) { |
|
1948 |
// ugghh... how would one do this efficiently for a non-contiguous space? |
|
1949 |
guarantee(false, "NYI"); |
|
1950 |
} |
|
1951 |
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1952 |
bool CompactibleFreeListSpace::linearAllocationWouldFail() const { |
1 | 1953 |
return _smallLinearAllocBlock._word_size == 0; |
1954 |
} |
|
1955 |
||
1956 |
void CompactibleFreeListSpace::repairLinearAllocationBlocks() { |
|
1957 |
// Fix up linear allocation blocks to look like free blocks |
|
1958 |
repairLinearAllocBlock(&_smallLinearAllocBlock); |
|
1959 |
} |
|
1960 |
||
1961 |
void CompactibleFreeListSpace::repairLinearAllocBlock(LinearAllocBlock* blk) { |
|
1962 |
assert_locked(); |
|
1963 |
if (blk->_ptr != NULL) { |
|
1964 |
assert(blk->_word_size != 0 && blk->_word_size >= MinChunkSize, |
|
1965 |
"Minimum block size requirement"); |
|
1966 |
FreeChunk* fc = (FreeChunk*)(blk->_ptr); |
|
1967 |
fc->setSize(blk->_word_size); |
|
1968 |
fc->linkPrev(NULL); // mark as free |
|
1969 |
fc->dontCoalesce(); |
|
1970 |
assert(fc->isFree(), "just marked it free"); |
|
1971 |
assert(fc->cantCoalesce(), "just marked it uncoalescable"); |
|
1972 |
} |
|
1973 |
} |
|
1974 |
||
1975 |
void CompactibleFreeListSpace::refillLinearAllocBlocksIfNeeded() { |
|
1976 |
assert_locked(); |
|
1977 |
if (_smallLinearAllocBlock._ptr == NULL) { |
|
1978 |
assert(_smallLinearAllocBlock._word_size == 0, |
|
1979 |
"Size of linAB should be zero if the ptr is NULL"); |
|
1980 |
// Reset the linAB refill and allocation size limit. |
|
1981 |
_smallLinearAllocBlock.set(0, 0, 1024*SmallForLinearAlloc, SmallForLinearAlloc); |
|
1982 |
} |
|
1983 |
refillLinearAllocBlockIfNeeded(&_smallLinearAllocBlock); |
|
1984 |
} |
|
1985 |
||
1986 |
void |
|
1987 |
CompactibleFreeListSpace::refillLinearAllocBlockIfNeeded(LinearAllocBlock* blk) { |
|
1988 |
assert_locked(); |
|
1989 |
assert((blk->_ptr == NULL && blk->_word_size == 0) || |
|
1990 |
(blk->_ptr != NULL && blk->_word_size >= MinChunkSize), |
|
1991 |
"blk invariant"); |
|
1992 |
if (blk->_ptr == NULL) { |
|
1993 |
refillLinearAllocBlock(blk); |
|
1994 |
} |
|
1995 |
if (PrintMiscellaneous && Verbose) { |
|
1996 |
if (blk->_word_size == 0) { |
|
1997 |
warning("CompactibleFreeListSpace(prologue):: Linear allocation failure"); |
|
1998 |
} |
|
1999 |
} |
|
2000 |
} |
|
2001 |
||
2002 |
void |
|
2003 |
CompactibleFreeListSpace::refillLinearAllocBlock(LinearAllocBlock* blk) { |
|
2004 |
assert_locked(); |
|
2005 |
assert(blk->_word_size == 0 && blk->_ptr == NULL, |
|
2006 |
"linear allocation block should be empty"); |
|
2007 |
FreeChunk* fc; |
|
2008 |
if (blk->_refillSize < SmallForDictionary && |
|
2009 |
(fc = getChunkFromIndexedFreeList(blk->_refillSize)) != NULL) { |
|
2010 |
// A linAB's strategy might be to use small sizes to reduce |
|
2011 |
// fragmentation but still get the benefits of allocation from a |
|
2012 |
// linAB. |
|
2013 |
} else { |
|
2014 |
fc = getChunkFromDictionary(blk->_refillSize); |
|
2015 |
} |
|
2016 |
if (fc != NULL) { |
|
2017 |
blk->_ptr = (HeapWord*)fc; |
|
2018 |
blk->_word_size = fc->size(); |
|
2019 |
fc->dontCoalesce(); // to prevent sweeper from sweeping us up |
|
2020 |
} |
|
2021 |
} |
|
2022 |
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|
2023 |
// Support for concurrent collection policy decisions. |
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|
2024 |
bool CompactibleFreeListSpace::should_concurrent_collect() const { |
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|
2025 |
// In the future we might want to add in frgamentation stats -- |
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|
2026 |
// including erosion of the "mountain" into this decision as well. |
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|
2027 |
return !adaptive_freelists() && linearAllocationWouldFail(); |
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|
2028 |
} |
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|
2029 |
|
1 | 2030 |
// Support for compaction |
2031 |
||
2032 |
void CompactibleFreeListSpace::prepare_for_compaction(CompactPoint* cp) { |
|
2033 |
SCAN_AND_FORWARD(cp,end,block_is_obj,block_size); |
|
2034 |
// prepare_for_compaction() uses the space between live objects |
|
2035 |
// so that later phase can skip dead space quickly. So verification |
|
2036 |
// of the free lists doesn't work after. |
|
2037 |
} |
|
2038 |
||
2039 |
#define obj_size(q) adjustObjectSize(oop(q)->size()) |
|
2040 |
#define adjust_obj_size(s) adjustObjectSize(s) |
|
2041 |
||
2042 |
void CompactibleFreeListSpace::adjust_pointers() { |
|
2043 |
// In other versions of adjust_pointers(), a bail out |
|
2044 |
// based on the amount of live data in the generation |
|
2045 |
// (i.e., if 0, bail out) may be used. |
|
2046 |
// Cannot test used() == 0 here because the free lists have already |
|
2047 |
// been mangled by the compaction. |
|
2048 |
||
2049 |
SCAN_AND_ADJUST_POINTERS(adjust_obj_size); |
|
2050 |
// See note about verification in prepare_for_compaction(). |
|
2051 |
} |
|
2052 |
||
2053 |
void CompactibleFreeListSpace::compact() { |
|
2054 |
SCAN_AND_COMPACT(obj_size); |
|
2055 |
} |
|
2056 |
||
2057 |
// fragmentation_metric = 1 - [sum of (fbs**2) / (sum of fbs)**2] |
|
2058 |
// where fbs is free block sizes |
|
2059 |
double CompactibleFreeListSpace::flsFrag() const { |
|
2060 |
size_t itabFree = totalSizeInIndexedFreeLists(); |
|
2061 |
double frag = 0.0; |
|
2062 |
size_t i; |
|
2063 |
||
2064 |
for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
|
2065 |
double sz = i; |
|
2066 |
frag += _indexedFreeList[i].count() * (sz * sz); |
|
2067 |
} |
|
2068 |
||
2069 |
double totFree = itabFree + |
|
2070 |
_dictionary->totalChunkSize(DEBUG_ONLY(freelistLock())); |
|
2071 |
if (totFree > 0) { |
|
2072 |
frag = ((frag + _dictionary->sum_of_squared_block_sizes()) / |
|
2073 |
(totFree * totFree)); |
|
2074 |
frag = (double)1.0 - frag; |
|
2075 |
} else { |
|
2076 |
assert(frag == 0.0, "Follows from totFree == 0"); |
|
2077 |
} |
|
2078 |
return frag; |
|
2079 |
} |
|
2080 |
||
2081 |
void CompactibleFreeListSpace::beginSweepFLCensus( |
|
2082 |
float inter_sweep_current, |
|
4574
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|
2083 |
float inter_sweep_estimate, |
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|
2084 |
float intra_sweep_estimate) { |
1 | 2085 |
assert_locked(); |
2086 |
size_t i; |
|
2087 |
for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
|
2088 |
FreeList* fl = &_indexedFreeList[i]; |
|
4574
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|
2089 |
if (PrintFLSStatistics > 1) { |
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|
2090 |
gclog_or_tty->print("size[%d] : ", i); |
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|
2091 |
} |
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|
2092 |
fl->compute_desired(inter_sweep_current, inter_sweep_estimate, intra_sweep_estimate); |
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|
2093 |
fl->set_coalDesired((ssize_t)((double)fl->desired() * CMSSmallCoalSurplusPercent)); |
1 | 2094 |
fl->set_beforeSweep(fl->count()); |
2095 |
fl->set_bfrSurp(fl->surplus()); |
|
2096 |
} |
|
4574
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|
2097 |
_dictionary->beginSweepDictCensus(CMSLargeCoalSurplusPercent, |
1 | 2098 |
inter_sweep_current, |
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|
2099 |
inter_sweep_estimate, |
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|
2100 |
intra_sweep_estimate); |
1 | 2101 |
} |
2102 |
||
2103 |
void CompactibleFreeListSpace::setFLSurplus() { |
|
2104 |
assert_locked(); |
|
2105 |
size_t i; |
|
2106 |
for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
|
2107 |
FreeList *fl = &_indexedFreeList[i]; |
|
2108 |
fl->set_surplus(fl->count() - |
|
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|
2109 |
(ssize_t)((double)fl->desired() * CMSSmallSplitSurplusPercent)); |
1 | 2110 |
} |
2111 |
} |
|
2112 |
||
2113 |
void CompactibleFreeListSpace::setFLHints() { |
|
2114 |
assert_locked(); |
|
2115 |
size_t i; |
|
2116 |
size_t h = IndexSetSize; |
|
2117 |
for (i = IndexSetSize - 1; i != 0; i -= IndexSetStride) { |
|
2118 |
FreeList *fl = &_indexedFreeList[i]; |
|
2119 |
fl->set_hint(h); |
|
2120 |
if (fl->surplus() > 0) { |
|
2121 |
h = i; |
|
2122 |
} |
|
2123 |
} |
|
2124 |
} |
|
2125 |
||
2126 |
void CompactibleFreeListSpace::clearFLCensus() { |
|
2127 |
assert_locked(); |
|
2128 |
int i; |
|
2129 |
for (i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
|
2130 |
FreeList *fl = &_indexedFreeList[i]; |
|
2131 |
fl->set_prevSweep(fl->count()); |
|
2132 |
fl->set_coalBirths(0); |
|
2133 |
fl->set_coalDeaths(0); |
|
2134 |
fl->set_splitBirths(0); |
|
2135 |
fl->set_splitDeaths(0); |
|
2136 |
} |
|
2137 |
} |
|
2138 |
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|
2139 |
void CompactibleFreeListSpace::endSweepFLCensus(size_t sweep_count) { |
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|
2140 |
if (PrintFLSStatistics > 0) { |
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|
2141 |
HeapWord* largestAddr = (HeapWord*) dictionary()->findLargestDict(); |
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|
2142 |
gclog_or_tty->print_cr("CMS: Large block " PTR_FORMAT, |
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|
2143 |
largestAddr); |
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|
2144 |
} |
1 | 2145 |
setFLSurplus(); |
2146 |
setFLHints(); |
|
2147 |
if (PrintGC && PrintFLSCensus > 0) { |
|
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|
2148 |
printFLCensus(sweep_count); |
1 | 2149 |
} |
2150 |
clearFLCensus(); |
|
2151 |
assert_locked(); |
|
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|
2152 |
_dictionary->endSweepDictCensus(CMSLargeSplitSurplusPercent); |
1 | 2153 |
} |
2154 |
||
2155 |
bool CompactibleFreeListSpace::coalOverPopulated(size_t size) { |
|
2156 |
if (size < SmallForDictionary) { |
|
2157 |
FreeList *fl = &_indexedFreeList[size]; |
|
2158 |
return (fl->coalDesired() < 0) || |
|
2159 |
((int)fl->count() > fl->coalDesired()); |
|
2160 |
} else { |
|
2161 |
return dictionary()->coalDictOverPopulated(size); |
|
2162 |
} |
|
2163 |
} |
|
2164 |
||
2165 |
void CompactibleFreeListSpace::smallCoalBirth(size_t size) { |
|
2166 |
assert(size < SmallForDictionary, "Size too large for indexed list"); |
|
2167 |
FreeList *fl = &_indexedFreeList[size]; |
|
2168 |
fl->increment_coalBirths(); |
|
2169 |
fl->increment_surplus(); |
|
2170 |
} |
|
2171 |
||
2172 |
void CompactibleFreeListSpace::smallCoalDeath(size_t size) { |
|
2173 |
assert(size < SmallForDictionary, "Size too large for indexed list"); |
|
2174 |
FreeList *fl = &_indexedFreeList[size]; |
|
2175 |
fl->increment_coalDeaths(); |
|
2176 |
fl->decrement_surplus(); |
|
2177 |
} |
|
2178 |
||
2179 |
void CompactibleFreeListSpace::coalBirth(size_t size) { |
|
2180 |
if (size < SmallForDictionary) { |
|
2181 |
smallCoalBirth(size); |
|
2182 |
} else { |
|
2183 |
dictionary()->dictCensusUpdate(size, |
|
2184 |
false /* split */, |
|
2185 |
true /* birth */); |
|
2186 |
} |
|
2187 |
} |
|
2188 |
||
2189 |
void CompactibleFreeListSpace::coalDeath(size_t size) { |
|
2190 |
if(size < SmallForDictionary) { |
|
2191 |
smallCoalDeath(size); |
|
2192 |
} else { |
|
2193 |
dictionary()->dictCensusUpdate(size, |
|
2194 |
false /* split */, |
|
2195 |
false /* birth */); |
|
2196 |
} |
|
2197 |
} |
|
2198 |
||
2199 |
void CompactibleFreeListSpace::smallSplitBirth(size_t size) { |
|
2200 |
assert(size < SmallForDictionary, "Size too large for indexed list"); |
|
2201 |
FreeList *fl = &_indexedFreeList[size]; |
|
2202 |
fl->increment_splitBirths(); |
|
2203 |
fl->increment_surplus(); |
|
2204 |
} |
|
2205 |
||
2206 |
void CompactibleFreeListSpace::smallSplitDeath(size_t size) { |
|
2207 |
assert(size < SmallForDictionary, "Size too large for indexed list"); |
|
2208 |
FreeList *fl = &_indexedFreeList[size]; |
|
2209 |
fl->increment_splitDeaths(); |
|
2210 |
fl->decrement_surplus(); |
|
2211 |
} |
|
2212 |
||
2213 |
void CompactibleFreeListSpace::splitBirth(size_t size) { |
|
2214 |
if (size < SmallForDictionary) { |
|
2215 |
smallSplitBirth(size); |
|
2216 |
} else { |
|
2217 |
dictionary()->dictCensusUpdate(size, |
|
2218 |
true /* split */, |
|
2219 |
true /* birth */); |
|
2220 |
} |
|
2221 |
} |
|
2222 |
||
2223 |
void CompactibleFreeListSpace::splitDeath(size_t size) { |
|
2224 |
if (size < SmallForDictionary) { |
|
2225 |
smallSplitDeath(size); |
|
2226 |
} else { |
|
2227 |
dictionary()->dictCensusUpdate(size, |
|
2228 |
true /* split */, |
|
2229 |
false /* birth */); |
|
2230 |
} |
|
2231 |
} |
|
2232 |
||
2233 |
void CompactibleFreeListSpace::split(size_t from, size_t to1) { |
|
2234 |
size_t to2 = from - to1; |
|
2235 |
splitDeath(from); |
|
2236 |
splitBirth(to1); |
|
2237 |
splitBirth(to2); |
|
2238 |
} |
|
2239 |
||
2240 |
void CompactibleFreeListSpace::print() const { |
|
2241 |
tty->print(" CompactibleFreeListSpace"); |
|
2242 |
Space::print(); |
|
2243 |
} |
|
2244 |
||
2245 |
void CompactibleFreeListSpace::prepare_for_verify() { |
|
2246 |
assert_locked(); |
|
2247 |
repairLinearAllocationBlocks(); |
|
2248 |
// Verify that the SpoolBlocks look like free blocks of |
|
2249 |
// appropriate sizes... To be done ... |
|
2250 |
} |
|
2251 |
||
2252 |
class VerifyAllBlksClosure: public BlkClosure { |
|
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2253 |
private: |
1 | 2254 |
const CompactibleFreeListSpace* _sp; |
2255 |
const MemRegion _span; |
|
2256 |
||
2257 |
public: |
|
2258 |
VerifyAllBlksClosure(const CompactibleFreeListSpace* sp, |
|
2259 |
MemRegion span) : _sp(sp), _span(span) { } |
|
2260 |
||
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|
2261 |
virtual size_t do_blk(HeapWord* addr) { |
1 | 2262 |
size_t res; |
2263 |
if (_sp->block_is_obj(addr)) { |
|
2264 |
oop p = oop(addr); |
|
2265 |
guarantee(p->is_oop(), "Should be an oop"); |
|
2266 |
res = _sp->adjustObjectSize(p->size()); |
|
2267 |
if (_sp->obj_is_alive(addr)) { |
|
2268 |
p->verify(); |
|
2269 |
} |
|
2270 |
} else { |
|
2271 |
FreeChunk* fc = (FreeChunk*)addr; |
|
2272 |
res = fc->size(); |
|
2273 |
if (FLSVerifyLists && !fc->cantCoalesce()) { |
|
2274 |
guarantee(_sp->verifyChunkInFreeLists(fc), |
|
2275 |
"Chunk should be on a free list"); |
|
2276 |
} |
|
2277 |
} |
|
2278 |
guarantee(res != 0, "Livelock: no rank reduction!"); |
|
2279 |
return res; |
|
2280 |
} |
|
2281 |
}; |
|
2282 |
||
2283 |
class VerifyAllOopsClosure: public OopClosure { |
|
360
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|
2284 |
private: |
1 | 2285 |
const CMSCollector* _collector; |
2286 |
const CompactibleFreeListSpace* _sp; |
|
2287 |
const MemRegion _span; |
|
2288 |
const bool _past_remark; |
|
2289 |
const CMSBitMap* _bit_map; |
|
2290 |
||
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|
2291 |
protected: |
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|
2292 |
void do_oop(void* p, oop obj) { |
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|
2293 |
if (_span.contains(obj)) { // the interior oop points into CMS heap |
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|
2294 |
if (!_span.contains(p)) { // reference from outside CMS heap |
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|
2295 |
// Should be a valid object; the first disjunct below allows |
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|
2296 |
// us to sidestep an assertion in block_is_obj() that insists |
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|
2297 |
// that p be in _sp. Note that several generations (and spaces) |
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|
2298 |
// are spanned by _span (CMS heap) above. |
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|
2299 |
guarantee(!_sp->is_in_reserved(obj) || |
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|
2300 |
_sp->block_is_obj((HeapWord*)obj), |
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|
2301 |
"Should be an object"); |
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|
2302 |
guarantee(obj->is_oop(), "Should be an oop"); |
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|
2303 |
obj->verify(); |
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|
2304 |
if (_past_remark) { |
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|
2305 |
// Remark has been completed, the object should be marked |
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|
2306 |
_bit_map->isMarked((HeapWord*)obj); |
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|
2307 |
} |
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|
2308 |
} else { // reference within CMS heap |
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|
2309 |
if (_past_remark) { |
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|
2310 |
// Remark has been completed -- so the referent should have |
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|
2311 |
// been marked, if referring object is. |
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|
2312 |
if (_bit_map->isMarked(_collector->block_start(p))) { |
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|
2313 |
guarantee(_bit_map->isMarked((HeapWord*)obj), "Marking error?"); |
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|
2314 |
} |
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|
2315 |
} |
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|
2316 |
} |
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|
2317 |
} else if (_sp->is_in_reserved(p)) { |
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|
2318 |
// the reference is from FLS, and points out of FLS |
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|
2319 |
guarantee(obj->is_oop(), "Should be an oop"); |
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|
2320 |
obj->verify(); |
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|
2321 |
} |
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|
2322 |
} |
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|
2323 |
|
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|
2324 |
template <class T> void do_oop_work(T* p) { |
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|
2325 |
T heap_oop = oopDesc::load_heap_oop(p); |
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|
2326 |
if (!oopDesc::is_null(heap_oop)) { |
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|
2327 |
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); |
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|
2328 |
do_oop(p, obj); |
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|
2329 |
} |
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|
2330 |
} |
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|
2331 |
|
1 | 2332 |
public: |
2333 |
VerifyAllOopsClosure(const CMSCollector* collector, |
|
2334 |
const CompactibleFreeListSpace* sp, MemRegion span, |
|
2335 |
bool past_remark, CMSBitMap* bit_map) : |
|
2336 |
OopClosure(), _collector(collector), _sp(sp), _span(span), |
|
2337 |
_past_remark(past_remark), _bit_map(bit_map) { } |
|
2338 |
||
360
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|
2339 |
virtual void do_oop(oop* p) { VerifyAllOopsClosure::do_oop_work(p); } |
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|
2340 |
virtual void do_oop(narrowOop* p) { VerifyAllOopsClosure::do_oop_work(p); } |
1 | 2341 |
}; |
2342 |
||
2343 |
void CompactibleFreeListSpace::verify(bool ignored) const { |
|
2344 |
assert_lock_strong(&_freelistLock); |
|
2345 |
verify_objects_initialized(); |
|
2346 |
MemRegion span = _collector->_span; |
|
2347 |
bool past_remark = (_collector->abstract_state() == |
|
2348 |
CMSCollector::Sweeping); |
|
2349 |
||
2350 |
ResourceMark rm; |
|
2351 |
HandleMark hm; |
|
2352 |
||
2353 |
// Check integrity of CFL data structures |
|
2354 |
_promoInfo.verify(); |
|
2355 |
_dictionary->verify(); |
|
2356 |
if (FLSVerifyIndexTable) { |
|
2357 |
verifyIndexedFreeLists(); |
|
2358 |
} |
|
2359 |
// Check integrity of all objects and free blocks in space |
|
2360 |
{ |
|
2361 |
VerifyAllBlksClosure cl(this, span); |
|
2362 |
((CompactibleFreeListSpace*)this)->blk_iterate(&cl); // cast off const |
|
2363 |
} |
|
2364 |
// Check that all references in the heap to FLS |
|
2365 |
// are to valid objects in FLS or that references in |
|
2366 |
// FLS are to valid objects elsewhere in the heap |
|
2367 |
if (FLSVerifyAllHeapReferences) |
|
2368 |
{ |
|
2369 |
VerifyAllOopsClosure cl(_collector, this, span, past_remark, |
|
2370 |
_collector->markBitMap()); |
|
2371 |
CollectedHeap* ch = Universe::heap(); |
|
2372 |
ch->oop_iterate(&cl); // all oops in generations |
|
2373 |
ch->permanent_oop_iterate(&cl); // all oops in perm gen |
|
2374 |
} |
|
2375 |
||
2376 |
if (VerifyObjectStartArray) { |
|
2377 |
// Verify the block offset table |
|
2378 |
_bt.verify(); |
|
2379 |
} |
|
2380 |
} |
|
2381 |
||
2382 |
#ifndef PRODUCT |
|
2383 |
void CompactibleFreeListSpace::verifyFreeLists() const { |
|
2384 |
if (FLSVerifyLists) { |
|
2385 |
_dictionary->verify(); |
|
2386 |
verifyIndexedFreeLists(); |
|
2387 |
} else { |
|
2388 |
if (FLSVerifyDictionary) { |
|
2389 |
_dictionary->verify(); |
|
2390 |
} |
|
2391 |
if (FLSVerifyIndexTable) { |
|
2392 |
verifyIndexedFreeLists(); |
|
2393 |
} |
|
2394 |
} |
|
2395 |
} |
|
2396 |
#endif |
|
2397 |
||
2398 |
void CompactibleFreeListSpace::verifyIndexedFreeLists() const { |
|
2399 |
size_t i = 0; |
|
2400 |
for (; i < MinChunkSize; i++) { |
|
2401 |
guarantee(_indexedFreeList[i].head() == NULL, "should be NULL"); |
|
2402 |
} |
|
2403 |
for (; i < IndexSetSize; i++) { |
|
2404 |
verifyIndexedFreeList(i); |
|
2405 |
} |
|
2406 |
} |
|
2407 |
||
2408 |
void CompactibleFreeListSpace::verifyIndexedFreeList(size_t size) const { |
|
4574
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|
2409 |
FreeChunk* fc = _indexedFreeList[size].head(); |
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|
2410 |
FreeChunk* tail = _indexedFreeList[size].tail(); |
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|
2411 |
size_t num = _indexedFreeList[size].count(); |
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|
2412 |
size_t n = 0; |
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|
2413 |
guarantee((size % 2 == 0) || fc == NULL, "Odd slots should be empty"); |
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|
2414 |
for (; fc != NULL; fc = fc->next(), n++) { |
1 | 2415 |
guarantee(fc->size() == size, "Size inconsistency"); |
2416 |
guarantee(fc->isFree(), "!free?"); |
|
2417 |
guarantee(fc->next() == NULL || fc->next()->prev() == fc, "Broken list"); |
|
4574
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|
2418 |
guarantee((fc->next() == NULL) == (fc == tail), "Incorrect tail"); |
1 | 2419 |
} |
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|
2420 |
guarantee(n == num, "Incorrect count"); |
1 | 2421 |
} |
2422 |
||
2423 |
#ifndef PRODUCT |
|
2424 |
void CompactibleFreeListSpace::checkFreeListConsistency() const { |
|
2425 |
assert(_dictionary->minSize() <= IndexSetSize, |
|
2426 |
"Some sizes can't be allocated without recourse to" |
|
2427 |
" linear allocation buffers"); |
|
2428 |
assert(MIN_TREE_CHUNK_SIZE*HeapWordSize == sizeof(TreeChunk), |
|
2429 |
"else MIN_TREE_CHUNK_SIZE is wrong"); |
|
2430 |
assert((IndexSetStride == 2 && IndexSetStart == 2) || |
|
2431 |
(IndexSetStride == 1 && IndexSetStart == 1), "just checking"); |
|
2432 |
assert((IndexSetStride != 2) || (MinChunkSize % 2 == 0), |
|
2433 |
"Some for-loops may be incorrectly initialized"); |
|
2434 |
assert((IndexSetStride != 2) || (IndexSetSize % 2 == 1), |
|
2435 |
"For-loops that iterate over IndexSet with stride 2 may be wrong"); |
|
2436 |
} |
|
2437 |
#endif |
|
2438 |
||
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|
2439 |
void CompactibleFreeListSpace::printFLCensus(size_t sweep_count) const { |
1 | 2440 |
assert_lock_strong(&_freelistLock); |
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|
2441 |
FreeList total; |
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|
2442 |
gclog_or_tty->print("end sweep# " SIZE_FORMAT "\n", sweep_count); |
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diff
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|
2443 |
FreeList::print_labels_on(gclog_or_tty, "size"); |
1 | 2444 |
size_t totalFree = 0; |
2445 |
for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) { |
|
2446 |
const FreeList *fl = &_indexedFreeList[i]; |
|
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|
2447 |
totalFree += fl->count() * fl->size(); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
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1
diff
changeset
|
2448 |
if (i % (40*IndexSetStride) == 0) { |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
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1
diff
changeset
|
2449 |
FreeList::print_labels_on(gclog_or_tty, "size"); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2450 |
} |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2451 |
fl->print_on(gclog_or_tty); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
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1
diff
changeset
|
2452 |
total.set_bfrSurp( total.bfrSurp() + fl->bfrSurp() ); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
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parents:
1
diff
changeset
|
2453 |
total.set_surplus( total.surplus() + fl->surplus() ); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
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1
diff
changeset
|
2454 |
total.set_desired( total.desired() + fl->desired() ); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
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1
diff
changeset
|
2455 |
total.set_prevSweep( total.prevSweep() + fl->prevSweep() ); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2456 |
total.set_beforeSweep(total.beforeSweep() + fl->beforeSweep()); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2457 |
total.set_count( total.count() + fl->count() ); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2458 |
total.set_coalBirths( total.coalBirths() + fl->coalBirths() ); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2459 |
total.set_coalDeaths( total.coalDeaths() + fl->coalDeaths() ); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2460 |
total.set_splitBirths(total.splitBirths() + fl->splitBirths()); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2461 |
total.set_splitDeaths(total.splitDeaths() + fl->splitDeaths()); |
1 | 2462 |
} |
185
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2463 |
total.print_on(gclog_or_tty, "TOTAL"); |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2464 |
gclog_or_tty->print_cr("Total free in indexed lists " |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2465 |
SIZE_FORMAT " words", totalFree); |
1 | 2466 |
gclog_or_tty->print("growth: %8.5f deficit: %8.5f\n", |
185
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2467 |
(double)(total.splitBirths()+total.coalBirths()-total.splitDeaths()-total.coalDeaths())/ |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2468 |
(total.prevSweep() != 0 ? (double)total.prevSweep() : 1.0), |
cda2a1eb4be5
6668743: CMS: Consolidate block statistics reporting code
ysr
parents:
1
diff
changeset
|
2469 |
(double)(total.desired() - total.count())/(total.desired() != 0 ? (double)total.desired() : 1.0)); |
1 | 2470 |
_dictionary->printDictCensus(); |
2471 |
} |
|
2472 |
||
4574
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|
2473 |
/////////////////////////////////////////////////////////////////////////// |
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changeset
|
2474 |
// CFLS_LAB |
b2d5b0975515
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|
2475 |
/////////////////////////////////////////////////////////////////////////// |
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changeset
|
2476 |
|
b2d5b0975515
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changeset
|
2477 |
#define VECTOR_257(x) \ |
b2d5b0975515
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diff
changeset
|
2478 |
/* 1 2 3 4 5 6 7 8 9 1x 11 12 13 14 15 16 17 18 19 2x 21 22 23 24 25 26 27 28 29 3x 31 32 */ \ |
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changeset
|
2479 |
{ x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
b2d5b0975515
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diff
changeset
|
2480 |
x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
b2d5b0975515
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2105
diff
changeset
|
2481 |
x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2482 |
x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
b2d5b0975515
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ysr
parents:
2105
diff
changeset
|
2483 |
x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
b2d5b0975515
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ysr
parents:
2105
diff
changeset
|
2484 |
x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2485 |
x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
b2d5b0975515
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ysr
parents:
2105
diff
changeset
|
2486 |
x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, \ |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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parents:
2105
diff
changeset
|
2487 |
x } |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2488 |
|
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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parents:
2105
diff
changeset
|
2489 |
// Initialize with default setting of CMSParPromoteBlocksToClaim, _not_ |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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2105
diff
changeset
|
2490 |
// OldPLABSize, whose static default is different; if overridden at the |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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diff
changeset
|
2491 |
// command-line, this will get reinitialized via a call to |
b2d5b0975515
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ysr
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2105
diff
changeset
|
2492 |
// modify_initialization() below. |
b2d5b0975515
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2105
diff
changeset
|
2493 |
AdaptiveWeightedAverage CFLS_LAB::_blocks_to_claim[] = |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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2105
diff
changeset
|
2494 |
VECTOR_257(AdaptiveWeightedAverage(OldPLABWeight, (float)CMSParPromoteBlocksToClaim)); |
b2d5b0975515
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diff
changeset
|
2495 |
size_t CFLS_LAB::_global_num_blocks[] = VECTOR_257(0); |
b2d5b0975515
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diff
changeset
|
2496 |
int CFLS_LAB::_global_num_workers[] = VECTOR_257(0); |
1 | 2497 |
|
2498 |
CFLS_LAB::CFLS_LAB(CompactibleFreeListSpace* cfls) : |
|
2499 |
_cfls(cfls) |
|
2500 |
{ |
|
4574
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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diff
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|
2501 |
assert(CompactibleFreeListSpace::IndexSetSize == 257, "Modify VECTOR_257() macro above"); |
1 | 2502 |
for (size_t i = CompactibleFreeListSpace::IndexSetStart; |
2503 |
i < CompactibleFreeListSpace::IndexSetSize; |
|
2504 |
i += CompactibleFreeListSpace::IndexSetStride) { |
|
2505 |
_indexedFreeList[i].set_size(i); |
|
4574
b2d5b0975515
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diff
changeset
|
2506 |
_num_blocks[i] = 0; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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2105
diff
changeset
|
2507 |
} |
b2d5b0975515
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parents:
2105
diff
changeset
|
2508 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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2105
diff
changeset
|
2509 |
|
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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diff
changeset
|
2510 |
static bool _CFLS_LAB_modified = false; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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diff
changeset
|
2511 |
|
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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diff
changeset
|
2512 |
void CFLS_LAB::modify_initialization(size_t n, unsigned wt) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2513 |
assert(!_CFLS_LAB_modified, "Call only once"); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2514 |
_CFLS_LAB_modified = true; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2515 |
for (size_t i = CompactibleFreeListSpace::IndexSetStart; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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diff
changeset
|
2516 |
i < CompactibleFreeListSpace::IndexSetSize; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2517 |
i += CompactibleFreeListSpace::IndexSetStride) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2518 |
_blocks_to_claim[i].modify(n, wt, true /* force */); |
1 | 2519 |
} |
2520 |
} |
|
2521 |
||
2522 |
HeapWord* CFLS_LAB::alloc(size_t word_sz) { |
|
2523 |
FreeChunk* res; |
|
2524 |
word_sz = _cfls->adjustObjectSize(word_sz); |
|
2525 |
if (word_sz >= CompactibleFreeListSpace::IndexSetSize) { |
|
2526 |
// This locking manages sync with other large object allocations. |
|
2527 |
MutexLockerEx x(_cfls->parDictionaryAllocLock(), |
|
2528 |
Mutex::_no_safepoint_check_flag); |
|
2529 |
res = _cfls->getChunkFromDictionaryExact(word_sz); |
|
2530 |
if (res == NULL) return NULL; |
|
2531 |
} else { |
|
2532 |
FreeList* fl = &_indexedFreeList[word_sz]; |
|
2533 |
if (fl->count() == 0) { |
|
2534 |
// Attempt to refill this local free list. |
|
4574
b2d5b0975515
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ysr
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diff
changeset
|
2535 |
get_from_global_pool(word_sz, fl); |
1 | 2536 |
// If it didn't work, give up. |
2537 |
if (fl->count() == 0) return NULL; |
|
2538 |
} |
|
2539 |
res = fl->getChunkAtHead(); |
|
2540 |
assert(res != NULL, "Why was count non-zero?"); |
|
2541 |
} |
|
2542 |
res->markNotFree(); |
|
2543 |
assert(!res->isFree(), "shouldn't be marked free"); |
|
613 | 2544 |
assert(oop(res)->klass_or_null() == NULL, "should look uninitialized"); |
1 | 2545 |
// mangle a just allocated object with a distinct pattern. |
2546 |
debug_only(res->mangleAllocated(word_sz)); |
|
2547 |
return (HeapWord*)res; |
|
2548 |
} |
|
2549 |
||
4574
b2d5b0975515
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diff
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|
2550 |
// Get a chunk of blocks of the right size and update related |
b2d5b0975515
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diff
changeset
|
2551 |
// book-keeping stats |
b2d5b0975515
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diff
changeset
|
2552 |
void CFLS_LAB::get_from_global_pool(size_t word_sz, FreeList* fl) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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diff
changeset
|
2553 |
// Get the #blocks we want to claim |
b2d5b0975515
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ysr
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diff
changeset
|
2554 |
size_t n_blks = (size_t)_blocks_to_claim[word_sz].average(); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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2105
diff
changeset
|
2555 |
assert(n_blks > 0, "Error"); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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diff
changeset
|
2556 |
assert(ResizePLAB || n_blks == OldPLABSize, "Error"); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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diff
changeset
|
2557 |
// In some cases, when the application has a phase change, |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2558 |
// there may be a sudden and sharp shift in the object survival |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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diff
changeset
|
2559 |
// profile, and updating the counts at the end of a scavenge |
b2d5b0975515
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ysr
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diff
changeset
|
2560 |
// may not be quick enough, giving rise to large scavenge pauses |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2561 |
// during these phase changes. It is beneficial to detect such |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2562 |
// changes on-the-fly during a scavenge and avoid such a phase-change |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
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diff
changeset
|
2563 |
// pothole. The following code is a heuristic attempt to do that. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2564 |
// It is protected by a product flag until we have gained |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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diff
changeset
|
2565 |
// enough experience with this heuristic and fine-tuned its behaviour. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2566 |
// WARNING: This might increase fragmentation if we overreact to |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
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diff
changeset
|
2567 |
// small spikes, so some kind of historical smoothing based on |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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diff
changeset
|
2568 |
// previous experience with the greater reactivity might be useful. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2569 |
// Lacking sufficient experience, CMSOldPLABResizeQuicker is disabled by |
b2d5b0975515
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parents:
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diff
changeset
|
2570 |
// default. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
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diff
changeset
|
2571 |
if (ResizeOldPLAB && CMSOldPLABResizeQuicker) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2572 |
size_t multiple = _num_blocks[word_sz]/(CMSOldPLABToleranceFactor*CMSOldPLABNumRefills*n_blks); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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diff
changeset
|
2573 |
n_blks += CMSOldPLABReactivityFactor*multiple*n_blks; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
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diff
changeset
|
2574 |
n_blks = MIN2(n_blks, CMSOldPLABMax); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
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diff
changeset
|
2575 |
} |
b2d5b0975515
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ysr
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diff
changeset
|
2576 |
assert(n_blks > 0, "Error"); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2577 |
_cfls->par_get_chunk_of_blocks(word_sz, n_blks, fl); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
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diff
changeset
|
2578 |
// Update stats table entry for this block size |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2579 |
_num_blocks[word_sz] += fl->count(); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2580 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2581 |
|
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
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diff
changeset
|
2582 |
void CFLS_LAB::compute_desired_plab_size() { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2583 |
for (size_t i = CompactibleFreeListSpace::IndexSetStart; |
1 | 2584 |
i < CompactibleFreeListSpace::IndexSetSize; |
2585 |
i += CompactibleFreeListSpace::IndexSetStride) { |
|
4574
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2586 |
assert((_global_num_workers[i] == 0) == (_global_num_blocks[i] == 0), |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2587 |
"Counter inconsistency"); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2588 |
if (_global_num_workers[i] > 0) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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diff
changeset
|
2589 |
// Need to smooth wrt historical average |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2590 |
if (ResizeOldPLAB) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2591 |
_blocks_to_claim[i].sample( |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2592 |
MAX2((size_t)CMSOldPLABMin, |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2593 |
MIN2((size_t)CMSOldPLABMax, |
b2d5b0975515
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ysr
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2105
diff
changeset
|
2594 |
_global_num_blocks[i]/(_global_num_workers[i]*CMSOldPLABNumRefills)))); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2595 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2596 |
// Reset counters for next round |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2597 |
_global_num_workers[i] = 0; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2598 |
_global_num_blocks[i] = 0; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2599 |
if (PrintOldPLAB) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2600 |
gclog_or_tty->print_cr("[%d]: %d", i, (size_t)_blocks_to_claim[i].average()); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
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diff
changeset
|
2601 |
} |
1 | 2602 |
} |
2603 |
} |
|
2604 |
} |
|
2605 |
||
4574
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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|
2606 |
void CFLS_LAB::retire(int tid) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2607 |
// We run this single threaded with the world stopped; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2608 |
// so no need for locks and such. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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diff
changeset
|
2609 |
#define CFLS_LAB_PARALLEL_ACCESS 0 |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2610 |
NOT_PRODUCT(Thread* t = Thread::current();) |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2611 |
assert(Thread::current()->is_VM_thread(), "Error"); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2612 |
assert(CompactibleFreeListSpace::IndexSetStart == CompactibleFreeListSpace::IndexSetStride, |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2613 |
"Will access to uninitialized slot below"); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2614 |
#if CFLS_LAB_PARALLEL_ACCESS |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2615 |
for (size_t i = CompactibleFreeListSpace::IndexSetSize - 1; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2616 |
i > 0; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2617 |
i -= CompactibleFreeListSpace::IndexSetStride) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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2105
diff
changeset
|
2618 |
#else // CFLS_LAB_PARALLEL_ACCESS |
b2d5b0975515
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ysr
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2105
diff
changeset
|
2619 |
for (size_t i = CompactibleFreeListSpace::IndexSetStart; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2620 |
i < CompactibleFreeListSpace::IndexSetSize; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2621 |
i += CompactibleFreeListSpace::IndexSetStride) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2622 |
#endif // !CFLS_LAB_PARALLEL_ACCESS |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
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2105
diff
changeset
|
2623 |
assert(_num_blocks[i] >= (size_t)_indexedFreeList[i].count(), |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2624 |
"Can't retire more than what we obtained"); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2625 |
if (_num_blocks[i] > 0) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2626 |
size_t num_retire = _indexedFreeList[i].count(); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2627 |
assert(_num_blocks[i] > num_retire, "Should have used at least one"); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2628 |
{ |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2629 |
#if CFLS_LAB_PARALLEL_ACCESS |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2630 |
MutexLockerEx x(_cfls->_indexedFreeListParLocks[i], |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2631 |
Mutex::_no_safepoint_check_flag); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2632 |
#endif // CFLS_LAB_PARALLEL_ACCESS |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2633 |
// Update globals stats for num_blocks used |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2634 |
_global_num_blocks[i] += (_num_blocks[i] - num_retire); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2635 |
_global_num_workers[i]++; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2636 |
assert(_global_num_workers[i] <= (ssize_t)ParallelGCThreads, "Too big"); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2637 |
if (num_retire > 0) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2638 |
_cfls->_indexedFreeList[i].prepend(&_indexedFreeList[i]); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2639 |
// Reset this list. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2640 |
_indexedFreeList[i] = FreeList(); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2641 |
_indexedFreeList[i].set_size(i); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2642 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2643 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2644 |
if (PrintOldPLAB) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2645 |
gclog_or_tty->print_cr("%d[%d]: %d/%d/%d", |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2646 |
tid, i, num_retire, _num_blocks[i], (size_t)_blocks_to_claim[i].average()); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2647 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2648 |
// Reset stats for next round |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2649 |
_num_blocks[i] = 0; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2650 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2651 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2652 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2653 |
|
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2654 |
void CompactibleFreeListSpace:: par_get_chunk_of_blocks(size_t word_sz, size_t n, FreeList* fl) { |
1 | 2655 |
assert(fl->count() == 0, "Precondition."); |
2656 |
assert(word_sz < CompactibleFreeListSpace::IndexSetSize, |
|
2657 |
"Precondition"); |
|
2658 |
||
4574
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2659 |
// We'll try all multiples of word_sz in the indexed set, starting with |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2660 |
// word_sz itself and, if CMSSplitIndexedFreeListBlocks, try larger multiples, |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2661 |
// then try getting a big chunk and splitting it. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2662 |
{ |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2663 |
bool found; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2664 |
int k; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2665 |
size_t cur_sz; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2666 |
for (k = 1, cur_sz = k * word_sz, found = false; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2667 |
(cur_sz < CompactibleFreeListSpace::IndexSetSize) && |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2668 |
(CMSSplitIndexedFreeListBlocks || k <= 1); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2669 |
k++, cur_sz = k * word_sz) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2670 |
FreeList* gfl = &_indexedFreeList[cur_sz]; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2671 |
FreeList fl_for_cur_sz; // Empty. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2672 |
fl_for_cur_sz.set_size(cur_sz); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2673 |
{ |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2674 |
MutexLockerEx x(_indexedFreeListParLocks[cur_sz], |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2675 |
Mutex::_no_safepoint_check_flag); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2676 |
if (gfl->count() != 0) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2677 |
// nn is the number of chunks of size cur_sz that |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2678 |
// we'd need to split k-ways each, in order to create |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2679 |
// "n" chunks of size word_sz each. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2680 |
const size_t nn = MAX2(n/k, (size_t)1); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2681 |
gfl->getFirstNChunksFromList(nn, &fl_for_cur_sz); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2682 |
found = true; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2683 |
if (k > 1) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2684 |
// Update split death stats for the cur_sz-size blocks list: |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2685 |
// we increment the split death count by the number of blocks |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2686 |
// we just took from the cur_sz-size blocks list and which |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2687 |
// we will be splitting below. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2688 |
ssize_t deaths = _indexedFreeList[cur_sz].splitDeaths() + |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2689 |
fl_for_cur_sz.count(); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2690 |
_indexedFreeList[cur_sz].set_splitDeaths(deaths); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2691 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2692 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2693 |
} |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2694 |
// Now transfer fl_for_cur_sz to fl. Common case, we hope, is k = 1. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2695 |
if (found) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2696 |
if (k == 1) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2697 |
fl->prepend(&fl_for_cur_sz); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2698 |
} else { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2699 |
// Divide each block on fl_for_cur_sz up k ways. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2700 |
FreeChunk* fc; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2701 |
while ((fc = fl_for_cur_sz.getChunkAtHead()) != NULL) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2702 |
// Must do this in reverse order, so that anybody attempting to |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2703 |
// access the main chunk sees it as a single free block until we |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2704 |
// change it. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2705 |
size_t fc_size = fc->size(); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2706 |
for (int i = k-1; i >= 0; i--) { |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2707 |
FreeChunk* ffc = (FreeChunk*)((HeapWord*)fc + i * word_sz); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2708 |
ffc->setSize(word_sz); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2709 |
ffc->linkNext(NULL); |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2710 |
ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2711 |
// Above must occur before BOT is updated below. |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2712 |
// splitting from the right, fc_size == (k - i + 1) * wordsize |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2713 |
_bt.mark_block((HeapWord*)ffc, word_sz); |
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parents:
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diff
changeset
|
2714 |
fc_size -= word_sz; |
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parents:
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diff
changeset
|
2715 |
_bt.verify_not_unallocated((HeapWord*)ffc, ffc->size()); |
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parents:
2105
diff
changeset
|
2716 |
_bt.verify_single_block((HeapWord*)fc, fc_size); |
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parents:
2105
diff
changeset
|
2717 |
_bt.verify_single_block((HeapWord*)ffc, ffc->size()); |
b2d5b0975515
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parents:
2105
diff
changeset
|
2718 |
// Push this on "fl". |
b2d5b0975515
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parents:
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diff
changeset
|
2719 |
fl->returnChunkAtHead(ffc); |
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parents:
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diff
changeset
|
2720 |
} |
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parents:
2105
diff
changeset
|
2721 |
// TRAP |
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parents:
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diff
changeset
|
2722 |
assert(fl->tail()->next() == NULL, "List invariant."); |
b2d5b0975515
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parents:
2105
diff
changeset
|
2723 |
} |
b2d5b0975515
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parents:
2105
diff
changeset
|
2724 |
} |
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parents:
2105
diff
changeset
|
2725 |
// Update birth stats for this block size. |
b2d5b0975515
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ysr
parents:
2105
diff
changeset
|
2726 |
size_t num = fl->count(); |
b2d5b0975515
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parents:
2105
diff
changeset
|
2727 |
MutexLockerEx x(_indexedFreeListParLocks[word_sz], |
b2d5b0975515
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parents:
2105
diff
changeset
|
2728 |
Mutex::_no_safepoint_check_flag); |
b2d5b0975515
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ysr
parents:
2105
diff
changeset
|
2729 |
ssize_t births = _indexedFreeList[word_sz].splitBirths() + num; |
b2d5b0975515
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parents:
2105
diff
changeset
|
2730 |
_indexedFreeList[word_sz].set_splitBirths(births); |
b2d5b0975515
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parents:
2105
diff
changeset
|
2731 |
return; |
1 | 2732 |
} |
2733 |
} |
|
2734 |
} |
|
2735 |
// Otherwise, we'll split a block from the dictionary. |
|
2736 |
FreeChunk* fc = NULL; |
|
2737 |
FreeChunk* rem_fc = NULL; |
|
2738 |
size_t rem; |
|
2739 |
{ |
|
2740 |
MutexLockerEx x(parDictionaryAllocLock(), |
|
2741 |
Mutex::_no_safepoint_check_flag); |
|
2742 |
while (n > 0) { |
|
2743 |
fc = dictionary()->getChunk(MAX2(n * word_sz, |
|
2744 |
_dictionary->minSize()), |
|
2745 |
FreeBlockDictionary::atLeast); |
|
2746 |
if (fc != NULL) { |
|
2747 |
_bt.allocated((HeapWord*)fc, fc->size()); // update _unallocated_blk |
|
2748 |
dictionary()->dictCensusUpdate(fc->size(), |
|
2749 |
true /*split*/, |
|
2750 |
false /*birth*/); |
|
2751 |
break; |
|
2752 |
} else { |
|
2753 |
n--; |
|
2754 |
} |
|
2755 |
} |
|
2756 |
if (fc == NULL) return; |
|
4574
b2d5b0975515
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parents:
2105
diff
changeset
|
2757 |
assert((ssize_t)n >= 1, "Control point invariant"); |
1 | 2758 |
// Otherwise, split up that block. |
4574
b2d5b0975515
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ysr
parents:
2105
diff
changeset
|
2759 |
const size_t nn = fc->size() / word_sz; |
1 | 2760 |
n = MIN2(nn, n); |
4574
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2761 |
assert((ssize_t)n >= 1, "Control point invariant"); |
1 | 2762 |
rem = fc->size() - n * word_sz; |
2763 |
// If there is a remainder, and it's too small, allocate one fewer. |
|
2764 |
if (rem > 0 && rem < MinChunkSize) { |
|
2765 |
n--; rem += word_sz; |
|
2766 |
} |
|
4577
18d854d28d4e
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jmasa
parents:
4574
diff
changeset
|
2767 |
// Note that at this point we may have n == 0. |
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2768 |
assert((ssize_t)n >= 0, "Control point invariant"); |
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2769 |
|
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2770 |
// If n is 0, the chunk fc that was found is not large |
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2771 |
// enough to leave a viable remainder. We are unable to |
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2772 |
// allocate even one block. Return fc to the |
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2773 |
// dictionary and return, leaving "fl" empty. |
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2774 |
if (n == 0) { |
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2775 |
returnChunkToDictionary(fc); |
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2776 |
return; |
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2777 |
} |
18d854d28d4e
6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
jmasa
parents:
4574
diff
changeset
|
2778 |
|
1 | 2779 |
// First return the remainder, if any. |
2780 |
// Note that we hold the lock until we decide if we're going to give |
|
4574
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2781 |
// back the remainder to the dictionary, since a concurrent allocation |
1 | 2782 |
// may otherwise see the heap as empty. (We're willing to take that |
2783 |
// hit if the block is a small block.) |
|
2784 |
if (rem > 0) { |
|
2785 |
size_t prefix_size = n * word_sz; |
|
2786 |
rem_fc = (FreeChunk*)((HeapWord*)fc + prefix_size); |
|
2787 |
rem_fc->setSize(rem); |
|
2788 |
rem_fc->linkNext(NULL); |
|
2789 |
rem_fc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
|
2790 |
// Above must occur before BOT is updated below. |
|
4574
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2791 |
assert((ssize_t)n > 0 && prefix_size > 0 && rem_fc > fc, "Error"); |
1 | 2792 |
_bt.split_block((HeapWord*)fc, fc->size(), prefix_size); |
2793 |
if (rem >= IndexSetSize) { |
|
2794 |
returnChunkToDictionary(rem_fc); |
|
4574
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2795 |
dictionary()->dictCensusUpdate(rem, true /*split*/, true /*birth*/); |
1 | 2796 |
rem_fc = NULL; |
2797 |
} |
|
2798 |
// Otherwise, return it to the small list below. |
|
2799 |
} |
|
2800 |
} |
|
2801 |
if (rem_fc != NULL) { |
|
2802 |
MutexLockerEx x(_indexedFreeListParLocks[rem], |
|
2803 |
Mutex::_no_safepoint_check_flag); |
|
2804 |
_bt.verify_not_unallocated((HeapWord*)rem_fc, rem_fc->size()); |
|
2805 |
_indexedFreeList[rem].returnChunkAtHead(rem_fc); |
|
2806 |
smallSplitBirth(rem); |
|
2807 |
} |
|
4574
b2d5b0975515
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ysr
parents:
2105
diff
changeset
|
2808 |
assert((ssize_t)n > 0 && fc != NULL, "Consistency"); |
1 | 2809 |
// Now do the splitting up. |
2810 |
// Must do this in reverse order, so that anybody attempting to |
|
2811 |
// access the main chunk sees it as a single free block until we |
|
2812 |
// change it. |
|
2813 |
size_t fc_size = n * word_sz; |
|
2814 |
// All but first chunk in this loop |
|
2815 |
for (ssize_t i = n-1; i > 0; i--) { |
|
2816 |
FreeChunk* ffc = (FreeChunk*)((HeapWord*)fc + i * word_sz); |
|
2817 |
ffc->setSize(word_sz); |
|
2818 |
ffc->linkNext(NULL); |
|
2819 |
ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. |
|
2820 |
// Above must occur before BOT is updated below. |
|
2821 |
// splitting from the right, fc_size == (n - i + 1) * wordsize |
|
2822 |
_bt.mark_block((HeapWord*)ffc, word_sz); |
|
2823 |
fc_size -= word_sz; |
|
2824 |
_bt.verify_not_unallocated((HeapWord*)ffc, ffc->size()); |
|
2825 |
_bt.verify_single_block((HeapWord*)ffc, ffc->size()); |
|
2826 |
_bt.verify_single_block((HeapWord*)fc, fc_size); |
|
2827 |
// Push this on "fl". |
|
2828 |
fl->returnChunkAtHead(ffc); |
|
2829 |
} |
|
2830 |
// First chunk |
|
2831 |
fc->setSize(word_sz); |
|
2832 |
fc->linkNext(NULL); |
|
2833 |
fc->linkPrev(NULL); |
|
2834 |
_bt.verify_not_unallocated((HeapWord*)fc, fc->size()); |
|
2835 |
_bt.verify_single_block((HeapWord*)fc, fc->size()); |
|
2836 |
fl->returnChunkAtHead(fc); |
|
2837 |
||
4574
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2838 |
assert((ssize_t)n > 0 && (ssize_t)n == fl->count(), "Incorrect number of blocks"); |
1 | 2839 |
{ |
4574
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
ysr
parents:
2105
diff
changeset
|
2840 |
// Update the stats for this block size. |
1 | 2841 |
MutexLockerEx x(_indexedFreeListParLocks[word_sz], |
2842 |
Mutex::_no_safepoint_check_flag); |
|
4574
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parents:
2105
diff
changeset
|
2843 |
const ssize_t births = _indexedFreeList[word_sz].splitBirths() + n; |
b2d5b0975515
6631166: CMS: better heuristics when combatting fragmentation
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parents:
2105
diff
changeset
|
2844 |
_indexedFreeList[word_sz].set_splitBirths(births); |
b2d5b0975515
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parents:
2105
diff
changeset
|
2845 |
// ssize_t new_surplus = _indexedFreeList[word_sz].surplus() + n; |
b2d5b0975515
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ysr
parents:
2105
diff
changeset
|
2846 |
// _indexedFreeList[word_sz].set_surplus(new_surplus); |
1 | 2847 |
} |
2848 |
||
2849 |
// TRAP |
|
2850 |
assert(fl->tail()->next() == NULL, "List invariant."); |
|
2851 |
} |
|
2852 |
||
2853 |
// Set up the space's par_seq_tasks structure for work claiming |
|
2854 |
// for parallel rescan. See CMSParRemarkTask where this is currently used. |
|
2855 |
// XXX Need to suitably abstract and generalize this and the next |
|
2856 |
// method into one. |
|
2857 |
void |
|
2858 |
CompactibleFreeListSpace:: |
|
2859 |
initialize_sequential_subtasks_for_rescan(int n_threads) { |
|
2860 |
// The "size" of each task is fixed according to rescan_task_size. |
|
2861 |
assert(n_threads > 0, "Unexpected n_threads argument"); |
|
2862 |
const size_t task_size = rescan_task_size(); |
|
2863 |
size_t n_tasks = (used_region().word_size() + task_size - 1)/task_size; |
|
1372
654bcf7839bc
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
977
diff
changeset
|
2864 |
assert((n_tasks == 0) == used_region().is_empty(), "n_tasks incorrect"); |
654bcf7839bc
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
977
diff
changeset
|
2865 |
assert(n_tasks == 0 || |
654bcf7839bc
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
977
diff
changeset
|
2866 |
((used_region().start() + (n_tasks - 1)*task_size < used_region().end()) && |
654bcf7839bc
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
977
diff
changeset
|
2867 |
(used_region().start() + n_tasks*task_size >= used_region().end())), |
654bcf7839bc
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
977
diff
changeset
|
2868 |
"n_tasks calculation incorrect"); |
1 | 2869 |
SequentialSubTasksDone* pst = conc_par_seq_tasks(); |
2870 |
assert(!pst->valid(), "Clobbering existing data?"); |
|
2871 |
pst->set_par_threads(n_threads); |
|
2872 |
pst->set_n_tasks((int)n_tasks); |
|
2873 |
} |
|
2874 |
||
2875 |
// Set up the space's par_seq_tasks structure for work claiming |
|
2876 |
// for parallel concurrent marking. See CMSConcMarkTask where this is currently used. |
|
2877 |
void |
|
2878 |
CompactibleFreeListSpace:: |
|
2879 |
initialize_sequential_subtasks_for_marking(int n_threads, |
|
2880 |
HeapWord* low) { |
|
2881 |
// The "size" of each task is fixed according to rescan_task_size. |
|
2882 |
assert(n_threads > 0, "Unexpected n_threads argument"); |
|
2883 |
const size_t task_size = marking_task_size(); |
|
2884 |
assert(task_size > CardTableModRefBS::card_size_in_words && |
|
2885 |
(task_size % CardTableModRefBS::card_size_in_words == 0), |
|
2886 |
"Otherwise arithmetic below would be incorrect"); |
|
2887 |
MemRegion span = _gen->reserved(); |
|
2888 |
if (low != NULL) { |
|
2889 |
if (span.contains(low)) { |
|
2890 |
// Align low down to a card boundary so that |
|
2891 |
// we can use block_offset_careful() on span boundaries. |
|
2892 |
HeapWord* aligned_low = (HeapWord*)align_size_down((uintptr_t)low, |
|
2893 |
CardTableModRefBS::card_size); |
|
2894 |
// Clip span prefix at aligned_low |
|
2895 |
span = span.intersection(MemRegion(aligned_low, span.end())); |
|
2896 |
} else if (low > span.end()) { |
|
2897 |
span = MemRegion(low, low); // Null region |
|
2898 |
} // else use entire span |
|
2899 |
} |
|
2900 |
assert(span.is_empty() || |
|
2901 |
((uintptr_t)span.start() % CardTableModRefBS::card_size == 0), |
|
2902 |
"span should start at a card boundary"); |
|
2903 |
size_t n_tasks = (span.word_size() + task_size - 1)/task_size; |
|
2904 |
assert((n_tasks == 0) == span.is_empty(), "Inconsistency"); |
|
2905 |
assert(n_tasks == 0 || |
|
2906 |
((span.start() + (n_tasks - 1)*task_size < span.end()) && |
|
2907 |
(span.start() + n_tasks*task_size >= span.end())), |
|
1372
654bcf7839bc
6722116: CMS: Incorrect overflow handling when using parallel concurrent marking
ysr
parents:
977
diff
changeset
|
2908 |
"n_tasks calculation incorrect"); |
1 | 2909 |
SequentialSubTasksDone* pst = conc_par_seq_tasks(); |
2910 |
assert(!pst->valid(), "Clobbering existing data?"); |
|
2911 |
pst->set_par_threads(n_threads); |
|
2912 |
pst->set_n_tasks((int)n_tasks); |
|
2913 |
} |