--- old/src/share/vm/gc_implementation/shared/plab.cpp 2015-05-12 11:42:17.007281261 +0200 +++ /dev/null 2015-03-18 17:10:38.111854831 +0100 @@ -1,160 +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/plab.hpp" -#include "gc_interface/collectedHeap.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), _undo_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_undo_wasted(_undo_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; - _undo_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; -} - -void PLAB::add_undo_waste(HeapWord* obj, size_t word_sz) { - CollectedHeap::fill_with_object(obj, word_sz); - _undo_wasted += word_sz; -} - -void PLAB::undo_last_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; -} - -void PLAB::undo_allocation(HeapWord* obj, size_t word_sz) { - // Is the alloc in the current alloc buffer? - if (contains(obj)) { - assert(contains(obj + word_sz - 1), - "should contain whole object"); - undo_last_allocation(obj, word_sz); - } else { - add_undo_waste(obj, word_sz); - } -} - -// 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", " - "_undo_wasted: "SIZE_FORMAT, - _allocated, _wasted, _unused, _undo_wasted)); - - _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 --- /dev/null 2015-03-18 17:10:38.111854831 +0100 +++ new/src/share/vm/gc/shared/plab.cpp 2015-05-12 11:42:16.809273014 +0200 @@ -0,0 +1,160 @@ +/* + * 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/shared/collectedHeap.hpp" +#include "gc/shared/plab.hpp" +#include "gc/shared/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), _undo_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_undo_wasted(_undo_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; + _undo_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; +} + +void PLAB::add_undo_waste(HeapWord* obj, size_t word_sz) { + CollectedHeap::fill_with_object(obj, word_sz); + _undo_wasted += word_sz; +} + +void PLAB::undo_last_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; +} + +void PLAB::undo_allocation(HeapWord* obj, size_t word_sz) { + // Is the alloc in the current alloc buffer? + if (contains(obj)) { + assert(contains(obj + word_sz - 1), + "should contain whole object"); + undo_last_allocation(obj, word_sz); + } else { + add_undo_waste(obj, word_sz); + } +} + +// 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", " + "_undo_wasted: "SIZE_FORMAT, + _allocated, _wasted, _unused, _undo_wasted)); + + _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