Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/g1MonitoringSupport.cpp @ 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 | 55fb97c4c58d |
children | 63a4eb8bcd23 |
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/* * Copyright (c) 2011, 2013, 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/g1/g1MonitoringSupport.hpp" #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" #include "gc_implementation/g1/g1CollectorPolicy.hpp" G1GenerationCounters::G1GenerationCounters(G1MonitoringSupport* g1mm, const char* name, int ordinal, int spaces, size_t min_capacity, size_t max_capacity, size_t curr_capacity) : GenerationCounters(name, ordinal, spaces, min_capacity, max_capacity, curr_capacity), _g1mm(g1mm) { } // We pad the capacity three times given that the young generation // contains three spaces (eden and two survivors). G1YoungGenerationCounters::G1YoungGenerationCounters(G1MonitoringSupport* g1mm, const char* name) : G1GenerationCounters(g1mm, name, 0 /* ordinal */, 3 /* spaces */, G1MonitoringSupport::pad_capacity(0, 3) /* min_capacity */, G1MonitoringSupport::pad_capacity(g1mm->young_gen_max(), 3), G1MonitoringSupport::pad_capacity(0, 3) /* curr_capacity */) { if (UsePerfData) { update_all(); } } G1OldGenerationCounters::G1OldGenerationCounters(G1MonitoringSupport* g1mm, const char* name) : G1GenerationCounters(g1mm, name, 1 /* ordinal */, 1 /* spaces */, G1MonitoringSupport::pad_capacity(0) /* min_capacity */, G1MonitoringSupport::pad_capacity(g1mm->old_gen_max()), G1MonitoringSupport::pad_capacity(0) /* curr_capacity */) { if (UsePerfData) { update_all(); } } void G1YoungGenerationCounters::update_all() { size_t committed = G1MonitoringSupport::pad_capacity(_g1mm->young_gen_committed(), 3); _current_size->set_value(committed); } void G1OldGenerationCounters::update_all() { size_t committed = G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed()); _current_size->set_value(committed); } G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) : _g1h(g1h), _incremental_collection_counters(NULL), _full_collection_counters(NULL), _old_collection_counters(NULL), _old_space_counters(NULL), _young_collection_counters(NULL), _eden_counters(NULL), _from_counters(NULL), _to_counters(NULL), _overall_reserved(0), _overall_committed(0), _overall_used(0), _young_region_num(0), _young_gen_committed(0), _eden_committed(0), _eden_used(0), _survivor_committed(0), _survivor_used(0), _old_committed(0), _old_used(0) { _overall_reserved = g1h->max_capacity(); recalculate_sizes(); // Counters for GC collections // // name "collector.0". In a generational collector this would be the // young generation collection. _incremental_collection_counters = new CollectorCounters("G1 incremental collections", 0); // name "collector.1". In a generational collector this would be the // old generation collection. _full_collection_counters = new CollectorCounters("G1 stop-the-world full collections", 1); // timer sampling for all counters supporting sampling only update the // used value. See the take_sample() method. G1 requires both used and // capacity updated so sampling is not currently used. It might // be sufficient to update all counters in take_sample() even though // take_sample() only returns "used". When sampling was used, there // were some anomolous values emitted which may have been the consequence // of not updating all values simultaneously (i.e., see the calculation done // in eden_space_used(), is it possbile that the values used to // calculate either eden_used or survivor_used are being updated by // the collector when the sample is being done?). const bool sampled = false; // "Generation" and "Space" counters. // // name "generation.1" This is logically the old generation in // generational GC terms. The "1, 1" parameters are for // the n-th generation (=1) with 1 space. // Counters are created from minCapacity, maxCapacity, and capacity _old_collection_counters = new G1OldGenerationCounters(this, "old"); // name "generation.1.space.0" // Counters are created from maxCapacity, capacity, initCapacity, // and used. _old_space_counters = new HSpaceCounters("space", 0 /* ordinal */, pad_capacity(overall_reserved()) /* max_capacity */, pad_capacity(old_space_committed()) /* init_capacity */, _old_collection_counters); // Young collection set // name "generation.0". This is logically the young generation. // The "0, 3" are paremeters for the n-th genertaion (=0) with 3 spaces. // See _old_collection_counters for additional counters _young_collection_counters = new G1YoungGenerationCounters(this, "young"); // name "generation.0.space.0" // See _old_space_counters for additional counters _eden_counters = new HSpaceCounters("eden", 0 /* ordinal */, pad_capacity(overall_reserved()) /* max_capacity */, pad_capacity(eden_space_committed()) /* init_capacity */, _young_collection_counters); // name "generation.0.space.1" // See _old_space_counters for additional counters // Set the arguments to indicate that this survivor space is not used. _from_counters = new HSpaceCounters("s0", 1 /* ordinal */, pad_capacity(0) /* max_capacity */, pad_capacity(0) /* init_capacity */, _young_collection_counters); // name "generation.0.space.2" // See _old_space_counters for additional counters _to_counters = new HSpaceCounters("s1", 2 /* ordinal */, pad_capacity(overall_reserved()) /* max_capacity */, pad_capacity(survivor_space_committed()) /* init_capacity */, _young_collection_counters); if (UsePerfData) { // Given that this survivor space is not used, we update it here // once to reflect that its used space is 0 so that we don't have to // worry about updating it again later. _from_counters->update_used(0); } } void G1MonitoringSupport::recalculate_sizes() { G1CollectedHeap* g1 = g1h(); // Recalculate all the sizes from scratch. We assume that this is // called at a point where no concurrent updates to the various // values we read here are possible (i.e., at a STW phase at the end // of a GC). uint young_list_length = g1->young_list()->length(); uint survivor_list_length = g1->g1_policy()->recorded_survivor_regions(); assert(young_list_length >= survivor_list_length, "invariant"); uint eden_list_length = young_list_length - survivor_list_length; // Max length includes any potential extensions to the young gen // we'll do when the GC locker is active. uint young_list_max_length = g1->g1_policy()->young_list_max_length(); assert(young_list_max_length >= survivor_list_length, "invariant"); uint eden_list_max_length = young_list_max_length - survivor_list_length; _overall_used = g1->used_unlocked(); _eden_used = (size_t) eden_list_length * HeapRegion::GrainBytes; _survivor_used = (size_t) survivor_list_length * HeapRegion::GrainBytes; _young_region_num = young_list_length; _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used); // First calculate the committed sizes that can be calculated independently. _survivor_committed = _survivor_used; _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used); // Next, start with the overall committed size. _overall_committed = g1->capacity(); size_t committed = _overall_committed; // Remove the committed size we have calculated so far (for the // survivor and old space). assert(committed >= (_survivor_committed + _old_committed), "sanity"); committed -= _survivor_committed + _old_committed; // Next, calculate and remove the committed size for the eden. _eden_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes; // Somewhat defensive: be robust in case there are inaccuracies in // the calculations _eden_committed = MIN2(_eden_committed, committed); committed -= _eden_committed; // Finally, give the rest to the old space... _old_committed += committed; // ..and calculate the young gen committed. _young_gen_committed = _eden_committed + _survivor_committed; assert(_overall_committed == (_eden_committed + _survivor_committed + _old_committed), "the committed sizes should add up"); // Somewhat defensive: cap the eden used size to make sure it // never exceeds the committed size. _eden_used = MIN2(_eden_used, _eden_committed); // _survivor_committed and _old_committed are calculated in terms of // the corresponding _*_used value, so the next two conditions // should hold. assert(_survivor_used <= _survivor_committed, "post-condition"); assert(_old_used <= _old_committed, "post-condition"); } void G1MonitoringSupport::recalculate_eden_size() { G1CollectedHeap* g1 = g1h(); // When a new eden region is allocated, only the eden_used size is // affected (since we have recalculated everything else at the last GC). uint young_region_num = g1h()->young_list()->length(); if (young_region_num > _young_region_num) { uint diff = young_region_num - _young_region_num; _eden_used += (size_t) diff * HeapRegion::GrainBytes; // Somewhat defensive: cap the eden used size to make sure it // never exceeds the committed size. _eden_used = MIN2(_eden_used, _eden_committed); _young_region_num = young_region_num; } } void G1MonitoringSupport::update_sizes() { recalculate_sizes(); if (UsePerfData) { eden_counters()->update_capacity(pad_capacity(eden_space_committed())); eden_counters()->update_used(eden_space_used()); // only the to survivor space (s1) is active, so we don't need to // update the counteres for the from survivor space (s0) to_counters()->update_capacity(pad_capacity(survivor_space_committed())); to_counters()->update_used(survivor_space_used()); old_space_counters()->update_capacity(pad_capacity(old_space_committed())); old_space_counters()->update_used(old_space_used()); old_collection_counters()->update_all(); young_collection_counters()->update_all(); MetaspaceCounters::update_performance_counters(); CompressedClassSpaceCounters::update_performance_counters(); } } void G1MonitoringSupport::update_eden_size() { recalculate_eden_size(); if (UsePerfData) { eden_counters()->update_used(eden_space_used()); } }