jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1StringDedupThread.cpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/g1StringDedupThread.cpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/g1StringDedupThread.cpp

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

author: tschatzl
date: Fri, 10 Oct 2014 15:51:58 +0200
changeset 7257: e7d0505c8a30
parent 6906: 581e70386ec9
child 7535: 7ae4e26cb1e0
child 8452: 04a62a3d51d7
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) 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.
  *
  */
 #include "precompiled.hpp"
 #include "gc_implementation/g1/g1Log.hpp"
 #include "gc_implementation/g1/g1StringDedup.hpp"
 #include "gc_implementation/g1/g1StringDedupTable.hpp"
 #include "gc_implementation/g1/g1StringDedupThread.hpp"
 #include "gc_implementation/g1/g1StringDedupQueue.hpp"
 G1StringDedupThread* G1StringDedupThread::_thread = NULL;
 G1StringDedupThread::G1StringDedupThread() :
   ConcurrentGCThread() {
   set_name("String Deduplication Thread");
   create_and_start();
 }
 G1StringDedupThread::~G1StringDedupThread() {
   ShouldNotReachHere();
 }
 void G1StringDedupThread::create() {
   assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
   assert(_thread == NULL, "One string deduplication thread allowed");
   _thread = new G1StringDedupThread();
 }
 G1StringDedupThread* G1StringDedupThread::thread() {
   assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
   assert(_thread != NULL, "String deduplication thread not created");
   return _thread;
 }
 void G1StringDedupThread::print_on(outputStream* st) const {
   st->print("\"%s\" ", name());
   Thread::print_on(st);
   st->cr();
 }
 void G1StringDedupThread::run() {
   G1StringDedupStat total_stat;
   initialize_in_thread();
   wait_for_universe_init();
   // Main loop
   for (;;) {
     G1StringDedupStat stat;
     stat.mark_idle();
     // Wait for the queue to become non-empty
     G1StringDedupQueue::wait();
     if (_should_terminate) {
       break;
     }
     {
       // Include thread in safepoints
       SuspendibleThreadSetJoiner sts;
       stat.mark_exec();
       // Process the queue
       for (;;) {
         oop java_string = G1StringDedupQueue::pop();
         if (java_string == NULL) {
           break;
         }
         G1StringDedupTable::deduplicate(java_string, stat);
         // Safepoint this thread if needed
         if (sts.should_yield()) {
           stat.mark_block();
           sts.yield();
           stat.mark_unblock();
         }
       }
       G1StringDedupTable::trim_entry_cache();
       stat.mark_done();
       // Print statistics
       total_stat.add(stat);
       print(gclog_or_tty, stat, total_stat);
     }
   }
   terminate();
 }
 void G1StringDedupThread::stop() {
   {
     MonitorLockerEx ml(Terminator_lock);
     _thread->_should_terminate = true;
   }
   G1StringDedupQueue::cancel_wait();
   {
     MonitorLockerEx ml(Terminator_lock);
     while (!_thread->_has_terminated) {
       ml.wait();
     }
   }
 }
 void G1StringDedupThread::print(outputStream* st, const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat) {
   if (G1Log::fine() || PrintStringDeduplicationStatistics) {
     G1StringDedupStat::print_summary(st, last_stat, total_stat);
     if (PrintStringDeduplicationStatistics) {
       G1StringDedupStat::print_statistics(st, last_stat, false);
       G1StringDedupStat::print_statistics(st, total_stat, true);
       G1StringDedupTable::print_statistics(st);
       G1StringDedupQueue::print_statistics(st);
     }
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1StringDedupThread.cpp@e7d0505c8a30 (annotated)

src/share/vm/gc_implementation/g1/g1StringDedupThread.cpp