# HG changeset patch # User jprovino # Date 1429112540 14400 # Node ID faa43d41b739a36f30f5b92160e7d13fd70e5aa8 # Parent a7bfa4e20897780e448b67b10d9dcd9f1bfe31da 8074545: Rename and clean up the ParGCAllocBuffer class Summary: Rename ParGCAllocBuffer to PLAB and rename affected files. Reviewed-by: tschatzl, kbarrett diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/g1/g1Allocator.cpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1Allocator.cpp Thu Apr 16 15:31:20 2015 +0200 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1Allocator.cpp Wed Apr 15 11:42:20 2015 -0400 @@ -110,15 +110,15 @@ _retained_old_gc_alloc_region = NULL; } -G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) : - ParGCAllocBuffer(gclab_word_size), _retired(true) { } +G1PLAB::G1PLAB(size_t gclab_word_size) : + PLAB(gclab_word_size), _retired(true) { } HeapWord* G1ParGCAllocator::allocate_direct_or_new_plab(InCSetState dest, size_t word_sz, AllocationContext_t context) { size_t gclab_word_size = _g1h->desired_plab_sz(dest); if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) { - G1ParGCAllocBuffer* alloc_buf = alloc_buffer(dest, context); + G1PLAB* alloc_buf = alloc_buffer(dest, context); add_to_alloc_buffer_waste(alloc_buf->words_remaining()); alloc_buf->retire(); @@ -151,7 +151,7 @@ void G1DefaultParGCAllocator::retire_alloc_buffers() { for (uint state = 0; state < InCSetState::Num; state++) { - G1ParGCAllocBuffer* const buf = _alloc_buffers[state]; + G1PLAB* const buf = _alloc_buffers[state]; if (buf != NULL) { add_to_alloc_buffer_waste(buf->words_remaining()); buf->flush_and_retire_stats(_g1h->alloc_buffer_stats(state)); diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/g1/g1Allocator.hpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1Allocator.hpp Thu Apr 16 15:31:20 2015 +0200 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1Allocator.hpp Wed Apr 15 11:42:20 2015 -0400 @@ -28,7 +28,7 @@ #include "gc_implementation/g1/g1AllocationContext.hpp" #include "gc_implementation/g1/g1AllocRegion.hpp" #include "gc_implementation/g1/g1InCSetState.hpp" -#include "gc_implementation/shared/parGCAllocBuffer.hpp" +#include "gc_implementation/shared/plab.hpp" #include "gc_interface/collectedHeap.hpp" class EvacuationInfo; @@ -147,18 +147,18 @@ } }; -class G1ParGCAllocBuffer: public ParGCAllocBuffer { +class G1PLAB: public PLAB { private: bool _retired; public: - G1ParGCAllocBuffer(size_t gclab_word_size); - virtual ~G1ParGCAllocBuffer() { + G1PLAB(size_t gclab_word_size); + virtual ~G1PLAB() { guarantee(_retired, "Allocation buffer has not been retired"); } virtual void set_buf(HeapWord* buf) { - ParGCAllocBuffer::set_buf(buf); + PLAB::set_buf(buf); _retired = false; } @@ -166,7 +166,7 @@ if (_retired) { return; } - ParGCAllocBuffer::retire(); + PLAB::retire(); _retired = true; } }; @@ -190,7 +190,7 @@ void add_to_undo_waste(size_t waste) { _undo_waste += waste; } virtual void retire_alloc_buffers() = 0; - virtual G1ParGCAllocBuffer* alloc_buffer(InCSetState dest, AllocationContext_t context) = 0; + virtual G1PLAB* alloc_buffer(InCSetState dest, AllocationContext_t context) = 0; // Calculate the survivor space object alignment in bytes. Returns that or 0 if // there are no restrictions on survivor alignment. @@ -229,7 +229,7 @@ HeapWord* plab_allocate(InCSetState dest, size_t word_sz, AllocationContext_t context) { - G1ParGCAllocBuffer* buffer = alloc_buffer(dest, context); + G1PLAB* buffer = alloc_buffer(dest, context); if (_survivor_alignment_bytes == 0) { return buffer->allocate(word_sz); } else { @@ -259,14 +259,14 @@ }; class G1DefaultParGCAllocator : public G1ParGCAllocator { - G1ParGCAllocBuffer _surviving_alloc_buffer; - G1ParGCAllocBuffer _tenured_alloc_buffer; - G1ParGCAllocBuffer* _alloc_buffers[InCSetState::Num]; + G1PLAB _surviving_alloc_buffer; + G1PLAB _tenured_alloc_buffer; + G1PLAB* _alloc_buffers[InCSetState::Num]; public: G1DefaultParGCAllocator(G1CollectedHeap* g1h); - virtual G1ParGCAllocBuffer* alloc_buffer(InCSetState dest, AllocationContext_t context) { + virtual G1PLAB* alloc_buffer(InCSetState dest, AllocationContext_t context) { assert(dest.is_valid(), err_msg("Allocation buffer index out-of-bounds: " CSETSTATE_FORMAT, dest.value())); assert(_alloc_buffers[dest.value()] != NULL, diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp --- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Thu Apr 16 15:31:20 2015 +0200 +++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Wed Apr 15 11:42:20 2015 -0400 @@ -39,7 +39,6 @@ #include "gc_implementation/g1/heapRegionManager.hpp" #include "gc_implementation/g1/heapRegionSet.hpp" #include "gc_implementation/shared/hSpaceCounters.hpp" -#include "gc_implementation/shared/parGCAllocBuffer.hpp" #include "gc_interface/collectedHeap.hpp" #include "memory/barrierSet.hpp" #include "memory/memRegion.hpp" diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp --- a/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp Thu Apr 16 15:31:20 2015 +0200 +++ b/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp Wed Apr 15 11:42:20 2015 -0400 @@ -34,7 +34,7 @@ #include "gc_implementation/shared/gcTimer.hpp" #include "gc_implementation/shared/gcTrace.hpp" #include "gc_implementation/shared/gcTraceTime.hpp" -#include "gc_implementation/shared/parGCAllocBuffer.inline.hpp" +#include "gc_implementation/shared/plab.inline.hpp" #include "gc_implementation/shared/spaceDecorator.hpp" #include "memory/defNewGeneration.inline.hpp" #include "memory/genCollectedHeap.hpp" @@ -226,7 +226,7 @@ // buffer. HeapWord* obj = NULL; if (!_to_space_full) { - ParGCAllocBuffer* const plab = to_space_alloc_buffer(); + PLAB* const plab = to_space_alloc_buffer(); Space* const sp = to_space(); if (word_sz * 100 < ParallelGCBufferWastePct * plab->word_sz()) { @@ -236,7 +236,7 @@ HeapWord* buf_space = sp->par_allocate(buf_size); if (buf_space == NULL) { const size_t min_bytes = - ParGCAllocBuffer::min_size() << LogHeapWordSize; + PLAB::min_size() << LogHeapWordSize; size_t free_bytes = sp->free(); while(buf_space == NULL && free_bytes >= min_bytes) { buf_size = free_bytes >> LogHeapWordSize; @@ -252,7 +252,7 @@ record_survivor_plab(buf_space, buf_size); obj = plab->allocate_aligned(word_sz, SurvivorAlignmentInBytes); // Note that we cannot compare buf_size < word_sz below - // because of AlignmentReserve (see ParGCAllocBuffer::allocate()). + // because of AlignmentReserve (see PLAB::allocate()). assert(obj != NULL || plab->words_remaining() < word_sz, "Else should have been able to allocate"); // It's conceivable that we may be able to use the diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp --- a/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp Thu Apr 16 15:31:20 2015 +0200 +++ b/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp Wed Apr 15 11:42:20 2015 -0400 @@ -27,7 +27,7 @@ #include "gc_implementation/parNew/parOopClosures.hpp" #include "gc_implementation/shared/gcTrace.hpp" -#include "gc_implementation/shared/parGCAllocBuffer.hpp" +#include "gc_implementation/shared/plab.hpp" #include "gc_implementation/shared/copyFailedInfo.hpp" #include "memory/defNewGeneration.hpp" #include "memory/padded.hpp" @@ -65,7 +65,7 @@ ObjToScanQueue *_work_queue; Stack* const _overflow_stack; - ParGCAllocBuffer _to_space_alloc_buffer; + PLAB _to_space_alloc_buffer; ParScanWithoutBarrierClosure _to_space_closure; // scan_without_gc_barrier ParScanWithBarrierClosure _old_gen_closure; // scan_with_gc_barrier @@ -140,7 +140,7 @@ ObjToScanQueue* work_queue() { return _work_queue; } - ParGCAllocBuffer* to_space_alloc_buffer() { + PLAB* to_space_alloc_buffer() { return &_to_space_alloc_buffer; } diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/shared/parGCAllocBuffer.cpp --- a/hotspot/src/share/vm/gc_implementation/shared/parGCAllocBuffer.cpp Thu Apr 16 15:31:20 2015 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,134 +0,0 @@ -/* - * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - * - */ - -#include "precompiled.hpp" -#include "gc_implementation/shared/parGCAllocBuffer.hpp" -#include "memory/threadLocalAllocBuffer.hpp" -#include "oops/arrayOop.hpp" -#include "oops/oop.inline.hpp" - -size_t ParGCAllocBuffer::min_size() { - // Make sure that we return something that is larger than AlignmentReserve - return align_object_size(MAX2(MinTLABSize / HeapWordSize, (uintx)oopDesc::header_size())) + AlignmentReserve; -} - -size_t ParGCAllocBuffer::max_size() { - return ThreadLocalAllocBuffer::max_size(); -} - -ParGCAllocBuffer::ParGCAllocBuffer(size_t desired_plab_sz_) : - _word_sz(desired_plab_sz_), _bottom(NULL), _top(NULL), - _end(NULL), _hard_end(NULL), _allocated(0), _wasted(0) -{ - // ArrayOopDesc::header_size depends on command line initialization. - AlignmentReserve = oopDesc::header_size() > MinObjAlignment ? align_object_size(arrayOopDesc::header_size(T_INT)) : 0; - assert(min_size() > AlignmentReserve, - err_msg("Minimum PLAB size " SIZE_FORMAT" must be larger than alignment reserve " SIZE_FORMAT" " - "to be able to contain objects", min_size(), AlignmentReserve)); -} - -// If the minimum object size is greater than MinObjAlignment, we can -// end up with a shard at the end of the buffer that's smaller than -// the smallest object. We can't allow that because the buffer must -// look like it's full of objects when we retire it, so we make -// sure we have enough space for a filler int array object. -size_t ParGCAllocBuffer::AlignmentReserve; - -void ParGCAllocBuffer::flush_and_retire_stats(PLABStats* stats) { - // Retire the last allocation buffer. - size_t unused = retire_internal(); - - // Now flush the statistics. - stats->add_allocated(_allocated); - stats->add_wasted(_wasted); - stats->add_unused(unused); - - // Since we have flushed the stats we need to clear the _allocated and _wasted - // fields in case somebody retains an instance of this over GCs. Not doing so - // will artifically inflate the values in the statistics. - _allocated = 0; - _wasted = 0; -} - -void ParGCAllocBuffer::retire() { - _wasted += retire_internal(); -} - -size_t ParGCAllocBuffer::retire_internal() { - size_t result = 0; - if (_top < _hard_end) { - CollectedHeap::fill_with_object(_top, _hard_end); - result += invalidate(); - } - return result; -} - -// Compute desired plab size and latch result for later -// use. This should be called once at the end of parallel -// scavenge; it clears the sensor accumulators. -void PLABStats::adjust_desired_plab_sz(uint no_of_gc_workers) { - assert(ResizePLAB, "Not set"); - - assert(is_object_aligned(max_size()) && min_size() <= max_size(), - "PLAB clipping computation may be incorrect"); - - if (_allocated == 0) { - assert(_unused == 0, - err_msg("Inconsistency in PLAB stats: " - "_allocated: "SIZE_FORMAT", " - "_wasted: "SIZE_FORMAT", " - "_unused: "SIZE_FORMAT, - _allocated, _wasted, _unused)); - - _allocated = 1; - } - double wasted_frac = (double)_unused / (double)_allocated; - size_t target_refills = (size_t)((wasted_frac * TargetSurvivorRatio) / TargetPLABWastePct); - if (target_refills == 0) { - target_refills = 1; - } - size_t used = _allocated - _wasted - _unused; - size_t recent_plab_sz = used / (target_refills * no_of_gc_workers); - // Take historical weighted average - _filter.sample(recent_plab_sz); - // Clip from above and below, and align to object boundary - size_t new_plab_sz = MAX2(min_size(), (size_t)_filter.average()); - new_plab_sz = MIN2(max_size(), new_plab_sz); - new_plab_sz = align_object_size(new_plab_sz); - // Latch the result - if (PrintPLAB) { - gclog_or_tty->print(" (plab_sz = " SIZE_FORMAT" desired_plab_sz = " SIZE_FORMAT") ", recent_plab_sz, new_plab_sz); - } - _desired_plab_sz = new_plab_sz; - - reset(); -} - -#ifndef PRODUCT -void ParGCAllocBuffer::print() { - gclog_or_tty->print_cr("parGCAllocBuffer: _bottom: " PTR_FORMAT " _top: " PTR_FORMAT - " _end: " PTR_FORMAT " _hard_end: " PTR_FORMAT ")", - p2i(_bottom), p2i(_top), p2i(_end), p2i(_hard_end)); -} -#endif // !PRODUCT diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/shared/parGCAllocBuffer.hpp --- a/hotspot/src/share/vm/gc_implementation/shared/parGCAllocBuffer.hpp Thu Apr 16 15:31:20 2015 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,197 +0,0 @@ -/* - * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - * - */ - -#ifndef SHARE_VM_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP -#define SHARE_VM_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP - -#include "gc_implementation/shared/gcUtil.hpp" -#include "memory/allocation.hpp" -#include "runtime/atomic.hpp" -#include "utilities/globalDefinitions.hpp" - -// Forward declarations. -class PLABStats; - -// A per-thread allocation buffer used during GC. -class ParGCAllocBuffer: public CHeapObj { -protected: - char head[32]; - size_t _word_sz; // In HeapWord units - HeapWord* _bottom; - HeapWord* _top; - HeapWord* _end; // Last allocatable address + 1 - HeapWord* _hard_end; // _end + AlignmentReserve - // In support of ergonomic sizing of PLAB's - size_t _allocated; // in HeapWord units - size_t _wasted; // in HeapWord units - char tail[32]; - static size_t AlignmentReserve; - - // Force future allocations to fail and queries for contains() - // to return false. Returns the amount of unused space in this PLAB. - size_t invalidate() { - _end = _hard_end; - size_t remaining = pointer_delta(_end, _top); // Calculate remaining space. - _top = _end; // Force future allocations to fail. - _bottom = _end; // Force future contains() queries to return false. - return remaining; - } - - // Fill in remaining space with a dummy object and invalidate the PLAB. Returns - // the amount of remaining space. - size_t retire_internal(); - -public: - // Initializes the buffer to be empty, but with the given "word_sz". - // Must get initialized with "set_buf" for an allocation to succeed. - ParGCAllocBuffer(size_t word_sz); - virtual ~ParGCAllocBuffer() {} - - // Minimum PLAB size. - static size_t min_size(); - // Maximum PLAB size. - static size_t max_size(); - - // If an allocation of the given "word_sz" can be satisfied within the - // buffer, do the allocation, returning a pointer to the start of the - // allocated block. If the allocation request cannot be satisfied, - // return NULL. - HeapWord* allocate(size_t word_sz) { - HeapWord* res = _top; - if (pointer_delta(_end, _top) >= word_sz) { - _top = _top + word_sz; - return res; - } else { - return NULL; - } - } - - // Allocate the object aligned to "alignment_in_bytes". - HeapWord* allocate_aligned(size_t word_sz, unsigned short alignment_in_bytes); - - // Undo the last allocation in the buffer, which is required to be of the - // "obj" of the given "word_sz". - void undo_allocation(HeapWord* obj, size_t word_sz) { - assert(pointer_delta(_top, _bottom) >= word_sz, "Bad undo"); - assert(pointer_delta(_top, obj) == word_sz, "Bad undo"); - _top = obj; - } - - // The total (word) size of the buffer, including both allocated and - // unallocated space. - size_t word_sz() { return _word_sz; } - - // Should only be done if we are about to reset with a new buffer of the - // given size. - void set_word_size(size_t new_word_sz) { - assert(new_word_sz > AlignmentReserve, "Too small"); - _word_sz = new_word_sz; - } - - // The number of words of unallocated space remaining in the buffer. - size_t words_remaining() { - assert(_end >= _top, "Negative buffer"); - return pointer_delta(_end, _top, HeapWordSize); - } - - bool contains(void* addr) { - return (void*)_bottom <= addr && addr < (void*)_hard_end; - } - - // Sets the space of the buffer to be [buf, space+word_sz()). - virtual void set_buf(HeapWord* buf) { - _bottom = buf; - _top = _bottom; - _hard_end = _bottom + word_sz(); - _end = _hard_end - AlignmentReserve; - assert(_end >= _top, "Negative buffer"); - // In support of ergonomic sizing - _allocated += word_sz(); - } - - // Flush allocation statistics into the given PLABStats supporting ergonomic - // sizing of PLAB's and retire the current buffer. To be called at the end of - // GC. - void flush_and_retire_stats(PLABStats* stats); - - // Fills in the unallocated portion of the buffer with a garbage object and updates - // statistics. To be called during GC. - virtual void retire(); - - void print() PRODUCT_RETURN; -}; - -// PLAB book-keeping. -class PLABStats VALUE_OBJ_CLASS_SPEC { - size_t _allocated; // Total allocated - size_t _wasted; // of which wasted (internal fragmentation) - size_t _unused; // Unused in last buffer - size_t _desired_plab_sz;// Output of filter (below), suitably trimmed and quantized - AdaptiveWeightedAverage - _filter; // Integrator with decay - - void reset() { - _allocated = 0; - _wasted = 0; - _unused = 0; - } - public: - PLABStats(size_t desired_plab_sz_, unsigned wt) : - _allocated(0), - _wasted(0), - _unused(0), - _desired_plab_sz(desired_plab_sz_), - _filter(wt) - { } - - static const size_t min_size() { - return ParGCAllocBuffer::min_size(); - } - - static const size_t max_size() { - return ParGCAllocBuffer::max_size(); - } - - size_t desired_plab_sz() { - return _desired_plab_sz; - } - - // Updates the current desired PLAB size. Computes the new desired PLAB size, - // updates _desired_plab_sz and clears sensor accumulators. - void adjust_desired_plab_sz(uint no_of_gc_workers); - - void add_allocated(size_t v) { - Atomic::add_ptr(v, &_allocated); - } - - void add_unused(size_t v) { - Atomic::add_ptr(v, &_unused); - } - - void add_wasted(size_t v) { - Atomic::add_ptr(v, &_wasted); - } -}; - -#endif // SHARE_VM_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/shared/parGCAllocBuffer.inline.hpp --- a/hotspot/src/share/vm/gc_implementation/shared/parGCAllocBuffer.inline.hpp Thu Apr 16 15:31:20 2015 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,44 +0,0 @@ -/* - * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - * - */ - -#ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_PARGCALLOCBUFFER_INLINE_HPP -#define SHARE_VM_GC_IMPLEMENTATION_SHARED_PARGCALLOCBUFFER_INLINE_HPP - -#include "gc_implementation/shared/parGCAllocBuffer.hpp" -#include "gc_interface/collectedHeap.inline.hpp" - -HeapWord* ParGCAllocBuffer::allocate_aligned(size_t word_sz, unsigned short alignment_in_bytes) { - - HeapWord* res = CollectedHeap::align_allocation_or_fail(_top, _end, alignment_in_bytes); - if (res == NULL) { - return NULL; - } - - // Set _top so that allocate(), which expects _top to be correctly set, - // can be used below. - _top = res; - return allocate(word_sz); -} - -#endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_PARGCALLOCBUFFER_INLINE_HPP diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/shared/plab.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/src/share/vm/gc_implementation/shared/plab.cpp Wed Apr 15 11:42:20 2015 -0400 @@ -0,0 +1,134 @@ +/* + * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "gc_implementation/shared/plab.hpp" +#include "memory/threadLocalAllocBuffer.hpp" +#include "oops/arrayOop.hpp" +#include "oops/oop.inline.hpp" + +size_t PLAB::min_size() { + // Make sure that we return something that is larger than AlignmentReserve + return align_object_size(MAX2(MinTLABSize / HeapWordSize, (uintx)oopDesc::header_size())) + AlignmentReserve; +} + +size_t PLAB::max_size() { + return ThreadLocalAllocBuffer::max_size(); +} + +PLAB::PLAB(size_t desired_plab_sz_) : + _word_sz(desired_plab_sz_), _bottom(NULL), _top(NULL), + _end(NULL), _hard_end(NULL), _allocated(0), _wasted(0) +{ + // ArrayOopDesc::header_size depends on command line initialization. + AlignmentReserve = oopDesc::header_size() > MinObjAlignment ? align_object_size(arrayOopDesc::header_size(T_INT)) : 0; + assert(min_size() > AlignmentReserve, + err_msg("Minimum PLAB size " SIZE_FORMAT" must be larger than alignment reserve " SIZE_FORMAT" " + "to be able to contain objects", min_size(), AlignmentReserve)); +} + +// If the minimum object size is greater than MinObjAlignment, we can +// end up with a shard at the end of the buffer that's smaller than +// the smallest object. We can't allow that because the buffer must +// look like it's full of objects when we retire it, so we make +// sure we have enough space for a filler int array object. +size_t PLAB::AlignmentReserve; + +void PLAB::flush_and_retire_stats(PLABStats* stats) { + // Retire the last allocation buffer. + size_t unused = retire_internal(); + + // Now flush the statistics. + stats->add_allocated(_allocated); + stats->add_wasted(_wasted); + stats->add_unused(unused); + + // Since we have flushed the stats we need to clear the _allocated and _wasted + // fields in case somebody retains an instance of this over GCs. Not doing so + // will artifically inflate the values in the statistics. + _allocated = 0; + _wasted = 0; +} + +void PLAB::retire() { + _wasted += retire_internal(); +} + +size_t PLAB::retire_internal() { + size_t result = 0; + if (_top < _hard_end) { + CollectedHeap::fill_with_object(_top, _hard_end); + result += invalidate(); + } + return result; +} + +// Compute desired plab size and latch result for later +// use. This should be called once at the end of parallel +// scavenge; it clears the sensor accumulators. +void PLABStats::adjust_desired_plab_sz(uint no_of_gc_workers) { + assert(ResizePLAB, "Not set"); + + assert(is_object_aligned(max_size()) && min_size() <= max_size(), + "PLAB clipping computation may be incorrect"); + + if (_allocated == 0) { + assert(_unused == 0, + err_msg("Inconsistency in PLAB stats: " + "_allocated: "SIZE_FORMAT", " + "_wasted: "SIZE_FORMAT", " + "_unused: "SIZE_FORMAT, + _allocated, _wasted, _unused)); + + _allocated = 1; + } + double wasted_frac = (double)_unused / (double)_allocated; + size_t target_refills = (size_t)((wasted_frac * TargetSurvivorRatio) / TargetPLABWastePct); + if (target_refills == 0) { + target_refills = 1; + } + size_t used = _allocated - _wasted - _unused; + size_t recent_plab_sz = used / (target_refills * no_of_gc_workers); + // Take historical weighted average + _filter.sample(recent_plab_sz); + // Clip from above and below, and align to object boundary + size_t new_plab_sz = MAX2(min_size(), (size_t)_filter.average()); + new_plab_sz = MIN2(max_size(), new_plab_sz); + new_plab_sz = align_object_size(new_plab_sz); + // Latch the result + if (PrintPLAB) { + gclog_or_tty->print(" (plab_sz = " SIZE_FORMAT" desired_plab_sz = " SIZE_FORMAT") ", recent_plab_sz, new_plab_sz); + } + _desired_plab_sz = new_plab_sz; + + reset(); +} + +#ifndef PRODUCT +void PLAB::print() { + gclog_or_tty->print_cr("PLAB: _bottom: " PTR_FORMAT " _top: " PTR_FORMAT + " _end: " PTR_FORMAT " _hard_end: " PTR_FORMAT ")", + p2i(_bottom), p2i(_top), p2i(_end), p2i(_hard_end)); +} +#endif // !PRODUCT diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/shared/plab.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/src/share/vm/gc_implementation/shared/plab.hpp Wed Apr 15 11:42:20 2015 -0400 @@ -0,0 +1,197 @@ +/* + * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_PLAB_HPP +#define SHARE_VM_GC_IMPLEMENTATION_SHARED_PLAB_HPP + +#include "gc_implementation/shared/gcUtil.hpp" +#include "memory/allocation.hpp" +#include "runtime/atomic.hpp" +#include "utilities/globalDefinitions.hpp" + +// Forward declarations. +class PLABStats; + +// A per-thread allocation buffer used during GC. +class PLAB: public CHeapObj { +protected: + char head[32]; + size_t _word_sz; // In HeapWord units + HeapWord* _bottom; + HeapWord* _top; + HeapWord* _end; // Last allocatable address + 1 + HeapWord* _hard_end; // _end + AlignmentReserve + // In support of ergonomic sizing of PLAB's + size_t _allocated; // in HeapWord units + size_t _wasted; // in HeapWord units + char tail[32]; + static size_t AlignmentReserve; + + // Force future allocations to fail and queries for contains() + // to return false. Returns the amount of unused space in this PLAB. + size_t invalidate() { + _end = _hard_end; + size_t remaining = pointer_delta(_end, _top); // Calculate remaining space. + _top = _end; // Force future allocations to fail. + _bottom = _end; // Force future contains() queries to return false. + return remaining; + } + + // Fill in remaining space with a dummy object and invalidate the PLAB. Returns + // the amount of remaining space. + size_t retire_internal(); + +public: + // Initializes the buffer to be empty, but with the given "word_sz". + // Must get initialized with "set_buf" for an allocation to succeed. + PLAB(size_t word_sz); + virtual ~PLAB() {} + + // Minimum PLAB size. + static size_t min_size(); + // Maximum PLAB size. + static size_t max_size(); + + // If an allocation of the given "word_sz" can be satisfied within the + // buffer, do the allocation, returning a pointer to the start of the + // allocated block. If the allocation request cannot be satisfied, + // return NULL. + HeapWord* allocate(size_t word_sz) { + HeapWord* res = _top; + if (pointer_delta(_end, _top) >= word_sz) { + _top = _top + word_sz; + return res; + } else { + return NULL; + } + } + + // Allocate the object aligned to "alignment_in_bytes". + HeapWord* allocate_aligned(size_t word_sz, unsigned short alignment_in_bytes); + + // Undo the last allocation in the buffer, which is required to be of the + // "obj" of the given "word_sz". + void undo_allocation(HeapWord* obj, size_t word_sz) { + assert(pointer_delta(_top, _bottom) >= word_sz, "Bad undo"); + assert(pointer_delta(_top, obj) == word_sz, "Bad undo"); + _top = obj; + } + + // The total (word) size of the buffer, including both allocated and + // unallocated space. + size_t word_sz() { return _word_sz; } + + // Should only be done if we are about to reset with a new buffer of the + // given size. + void set_word_size(size_t new_word_sz) { + assert(new_word_sz > AlignmentReserve, "Too small"); + _word_sz = new_word_sz; + } + + // The number of words of unallocated space remaining in the buffer. + size_t words_remaining() { + assert(_end >= _top, "Negative buffer"); + return pointer_delta(_end, _top, HeapWordSize); + } + + bool contains(void* addr) { + return (void*)_bottom <= addr && addr < (void*)_hard_end; + } + + // Sets the space of the buffer to be [buf, space+word_sz()). + virtual void set_buf(HeapWord* buf) { + _bottom = buf; + _top = _bottom; + _hard_end = _bottom + word_sz(); + _end = _hard_end - AlignmentReserve; + assert(_end >= _top, "Negative buffer"); + // In support of ergonomic sizing + _allocated += word_sz(); + } + + // Flush allocation statistics into the given PLABStats supporting ergonomic + // sizing of PLAB's and retire the current buffer. To be called at the end of + // GC. + void flush_and_retire_stats(PLABStats* stats); + + // Fills in the unallocated portion of the buffer with a garbage object and updates + // statistics. To be called during GC. + virtual void retire(); + + void print() PRODUCT_RETURN; +}; + +// PLAB book-keeping. +class PLABStats VALUE_OBJ_CLASS_SPEC { + size_t _allocated; // Total allocated + size_t _wasted; // of which wasted (internal fragmentation) + size_t _unused; // Unused in last buffer + size_t _desired_plab_sz;// Output of filter (below), suitably trimmed and quantized + AdaptiveWeightedAverage + _filter; // Integrator with decay + + void reset() { + _allocated = 0; + _wasted = 0; + _unused = 0; + } + public: + PLABStats(size_t desired_plab_sz_, unsigned wt) : + _allocated(0), + _wasted(0), + _unused(0), + _desired_plab_sz(desired_plab_sz_), + _filter(wt) + { } + + static const size_t min_size() { + return PLAB::min_size(); + } + + static const size_t max_size() { + return PLAB::max_size(); + } + + size_t desired_plab_sz() { + return _desired_plab_sz; + } + + // Updates the current desired PLAB size. Computes the new desired PLAB size, + // updates _desired_plab_sz and clears sensor accumulators. + void adjust_desired_plab_sz(uint no_of_gc_workers); + + void add_allocated(size_t v) { + Atomic::add_ptr(v, &_allocated); + } + + void add_unused(size_t v) { + Atomic::add_ptr(v, &_unused); + } + + void add_wasted(size_t v) { + Atomic::add_ptr(v, &_wasted); + } +}; + +#endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_PLAB_HPP diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/gc_implementation/shared/plab.inline.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/src/share/vm/gc_implementation/shared/plab.inline.hpp Wed Apr 15 11:42:20 2015 -0400 @@ -0,0 +1,44 @@ +/* + * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_PLAB_INLINE_HPP +#define SHARE_VM_GC_IMPLEMENTATION_SHARED_PLAB_INLINE_HPP + +#include "gc_implementation/shared/plab.hpp" +#include "gc_interface/collectedHeap.inline.hpp" + +HeapWord* PLAB::allocate_aligned(size_t word_sz, unsigned short alignment_in_bytes) { + + HeapWord* res = CollectedHeap::align_allocation_or_fail(_top, _end, alignment_in_bytes); + if (res == NULL) { + return NULL; + } + + // Set _top so that allocate(), which expects _top to be correctly set, + // can be used below. + _top = res; + return allocate(word_sz); +} + +#endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_PLAB_INLINE_HPP diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/precompiled/precompiled.hpp --- a/hotspot/src/share/vm/precompiled/precompiled.hpp Thu Apr 16 15:31:20 2015 +0200 +++ b/hotspot/src/share/vm/precompiled/precompiled.hpp Wed Apr 15 11:42:20 2015 -0400 @@ -315,7 +315,7 @@ # include "gc_implementation/parallelScavenge/psYoungGen.hpp" # include "gc_implementation/shared/gcAdaptivePolicyCounters.hpp" # include "gc_implementation/shared/gcPolicyCounters.hpp" -# include "gc_implementation/shared/parGCAllocBuffer.hpp" +# include "gc_implementation/shared/plab.hpp" #endif // INCLUDE_ALL_GCS #endif // !DONT_USE_PRECOMPILED_HEADER diff -r a7bfa4e20897 -r faa43d41b739 hotspot/src/share/vm/runtime/globals.hpp --- a/hotspot/src/share/vm/runtime/globals.hpp Thu Apr 16 15:31:20 2015 +0200 +++ b/hotspot/src/share/vm/runtime/globals.hpp Wed Apr 15 11:42:20 2015 -0400 @@ -1960,7 +1960,7 @@ "collection") \ \ develop(uintx, PromotionFailureALotCount, 1000, \ - "Number of promotion failures occurring at ParGCAllocBuffer " \ + "Number of promotion failures occurring at PLAB " \ "refill attempts (ParNew) or promotion attempts " \ "(other young collectors)") \ \