Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/survRateGroup.hpp @ 20543:e7d0505c8a30
8059758: Footprint regressions with JDK-8038423
Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything.
Reviewed-by: jwilhelm, brutisso
author | tschatzl |
---|---|
date | Fri, 10 Oct 2014 15:51:58 +0200 |
parents | b9a9ed0f8eeb |
children |
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/* * Copyright (c) 2001, 2012, 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_G1_SURVRATEGROUP_HPP #define SHARE_VM_GC_IMPLEMENTATION_G1_SURVRATEGROUP_HPP #include "utilities/numberSeq.hpp" class G1CollectorPolicy; class SurvRateGroup : public CHeapObj<mtGC> { private: G1CollectorPolicy* _g1p; const char* _name; size_t _stats_arrays_length; double* _surv_rate; double* _accum_surv_rate_pred; double _last_pred; double _accum_surv_rate; TruncatedSeq** _surv_rate_pred; NumberSeq** _summary_surv_rates; size_t _summary_surv_rates_len; size_t _summary_surv_rates_max_len; int _all_regions_allocated; size_t _region_num; size_t _setup_seq_num; public: SurvRateGroup(G1CollectorPolicy* g1p, const char* name, size_t summary_surv_rates_len); void reset(); void start_adding_regions(); void stop_adding_regions(); void record_surviving_words(int age_in_group, size_t surv_words); void all_surviving_words_recorded(bool propagate); const char* name() { return _name; } size_t region_num() { return _region_num; } double accum_surv_rate_pred(int age) { assert(age >= 0, "must be"); if ((size_t)age < _stats_arrays_length) return _accum_surv_rate_pred[age]; else { double diff = (double) (age - _stats_arrays_length + 1); return _accum_surv_rate_pred[_stats_arrays_length-1] + diff * _last_pred; } } double accum_surv_rate(size_t adjustment); TruncatedSeq* get_seq(size_t age) { if (age >= _setup_seq_num) { guarantee( _setup_seq_num > 0, "invariant" ); age = _setup_seq_num-1; } TruncatedSeq* seq = _surv_rate_pred[age]; guarantee( seq != NULL, "invariant" ); return seq; } int next_age_index(); int age_in_group(int age_index) { int ret = (int) (_all_regions_allocated - age_index); assert( ret >= 0, "invariant" ); return ret; } void finished_recalculating_age_indexes() { _all_regions_allocated = 0; } #ifndef PRODUCT void print(); void print_surv_rate_summary(); #endif // PRODUCT }; #endif // SHARE_VM_GC_IMPLEMENTATION_G1_SURVRATEGROUP_HPP