jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp

Fri, 10 Oct 2014 15:51:58 +0200

author: tschatzl
date: Fri, 10 Oct 2014 15:51:58 +0200
changeset 7257: e7d0505c8a30
parent 7219: 8ba0078861d4
child 7535: 7ae4e26cb1e0
permissions: -rw-r--r--

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

 /*
  * Copyright (c) 2001, 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
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 #include "precompiled.hpp"
 #include "gc_implementation/g1/concurrentG1Refine.hpp"
 #include "gc_implementation/g1/concurrentG1RefineThread.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1HotCardCache.hpp"
 #include "runtime/java.hpp"
 ConcurrentG1Refine::ConcurrentG1Refine(G1CollectedHeap* g1h, CardTableEntryClosure* refine_closure) :
   _threads(NULL), _n_threads(0),
   _hot_card_cache(g1h)
 {
   // Ergomonically select initial concurrent refinement parameters
   if (FLAG_IS_DEFAULT(G1ConcRefinementGreenZone)) {
     FLAG_SET_DEFAULT(G1ConcRefinementGreenZone, MAX2<int>(ParallelGCThreads, 1));
   }
   set_green_zone(G1ConcRefinementGreenZone);
   if (FLAG_IS_DEFAULT(G1ConcRefinementYellowZone)) {
     FLAG_SET_DEFAULT(G1ConcRefinementYellowZone, green_zone() * 3);
   }
   set_yellow_zone(MAX2<int>(G1ConcRefinementYellowZone, green_zone()));
   if (FLAG_IS_DEFAULT(G1ConcRefinementRedZone)) {
     FLAG_SET_DEFAULT(G1ConcRefinementRedZone, yellow_zone() * 2);
   }
   set_red_zone(MAX2<int>(G1ConcRefinementRedZone, yellow_zone()));
   _n_worker_threads = thread_num();
   // We need one extra thread to do the young gen rset size sampling.
   _n_threads = _n_worker_threads + 1;
   reset_threshold_step();
   _threads = NEW_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _n_threads, mtGC);
   uint worker_id_offset = DirtyCardQueueSet::num_par_ids();
   ConcurrentG1RefineThread *next = NULL;
   for (uint i = _n_threads - 1; i != UINT_MAX; i--) {
     ConcurrentG1RefineThread* t = new ConcurrentG1RefineThread(this, next, refine_closure, worker_id_offset, i);
     assert(t != NULL, "Conc refine should have been created");
     if (t->osthread() == NULL) {
         vm_shutdown_during_initialization("Could not create ConcurrentG1RefineThread");
     }
     assert(t->cg1r() == this, "Conc refine thread should refer to this");
     _threads[i] = t;
     next = t;
   }
 }
 void ConcurrentG1Refine::reset_threshold_step() {
   if (FLAG_IS_DEFAULT(G1ConcRefinementThresholdStep)) {
     _thread_threshold_step = (yellow_zone() - green_zone()) / (worker_thread_num() + 1);
   } else {
     _thread_threshold_step = G1ConcRefinementThresholdStep;
   }
 }
 void ConcurrentG1Refine::init(G1RegionToSpaceMapper* card_counts_storage) {
   _hot_card_cache.initialize(card_counts_storage);
 }
 void ConcurrentG1Refine::stop() {
   if (_threads != NULL) {
     for (uint i = 0; i < _n_threads; i++) {
       _threads[i]->stop();
     }
   }
 }
 void ConcurrentG1Refine::reinitialize_threads() {
   reset_threshold_step();
   if (_threads != NULL) {
     for (uint i = 0; i < _n_threads; i++) {
       _threads[i]->initialize();
     }
   }
 }
 ConcurrentG1Refine::~ConcurrentG1Refine() {
   if (_threads != NULL) {
     for (uint i = 0; i < _n_threads; i++) {
       delete _threads[i];
     }
     FREE_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _threads, mtGC);
   }
 }
 void ConcurrentG1Refine::threads_do(ThreadClosure *tc) {
   if (_threads != NULL) {
     for (uint i = 0; i < _n_threads; i++) {
       tc->do_thread(_threads[i]);
     }
   }
 }
 void ConcurrentG1Refine::worker_threads_do(ThreadClosure * tc) {
   if (_threads != NULL) {
     for (uint i = 0; i < worker_thread_num(); i++) {
       tc->do_thread(_threads[i]);
     }
   }
 }
 uint ConcurrentG1Refine::thread_num() {
   return G1ConcRefinementThreads;
 }
 void ConcurrentG1Refine::print_worker_threads_on(outputStream* st) const {
   for (uint i = 0; i < _n_threads; ++i) {
     _threads[i]->print_on(st);
     st->cr();
   }
 }
 ConcurrentG1RefineThread * ConcurrentG1Refine::sampling_thread() const {
   return _threads[worker_thread_num()];
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp