jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp@15c5903cf9e1 (annotated)

src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp@15c5903cf9e1 (annotated)

src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp

Mon, 03 Aug 2009 12:59:30 -0700

author: johnc
date: Mon, 03 Aug 2009 12:59:30 -0700
changeset 1324: 15c5903cf9e1
parent 1320: 7f807f55161a
child 1371: e1fdf4fd34dc
permissions: -rw-r--r--

6865703: G1: Parallelize hot card cache cleanup
Summary: Have the GC worker threads clear the hot card cache in parallel by having each worker thread claim a chunk of the card cache and process the cards in that chunk. The size of the chunks that each thread will claim is determined at VM initialization from the size of the card cache and the number of worker threads.
Reviewed-by: jmasa, tonyp

 /*
  * Copyright 2001-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 #include "incls/_precompiled.incl"
 #include "incls/_concurrentG1RefineThread.cpp.incl"
 // ======= Concurrent Mark Thread ========
 // The CM thread is created when the G1 garbage collector is used
 ConcurrentG1RefineThread::
 ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r, ConcurrentG1RefineThread *next,
                          int worker_id_offset, int worker_id) :
   ConcurrentGCThread(),
   _worker_id_offset(worker_id_offset),
   _worker_id(worker_id),
   _active(false),
   _next(next),
   _cg1r(cg1r),
   _vtime_accum(0.0),
   _co_tracker(G1CRGroup),
   _interval_ms(5.0)
 {
   create_and_start();
 }
 void ConcurrentG1RefineThread::sample_young_list_rs_lengths() {
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   G1CollectorPolicy* g1p = g1h->g1_policy();
   if (g1p->adaptive_young_list_length()) {
     int regions_visited = 0;
     g1h->young_list_rs_length_sampling_init();
     while (g1h->young_list_rs_length_sampling_more()) {
       g1h->young_list_rs_length_sampling_next();
       ++regions_visited;
       // we try to yield every time we visit 10 regions
       if (regions_visited == 10) {
         if (_sts.should_yield()) {
           _sts.yield("G1 refine");
           // we just abandon the iteration
           break;
         }
         regions_visited = 0;
       }
     }
     g1p->check_prediction_validity();
   }
 }
 void ConcurrentG1RefineThread::run() {
   initialize_in_thread();
   _vtime_start = os::elapsedVTime();
   wait_for_universe_init();
   _co_tracker.enable();
   _co_tracker.start();
   while (!_should_terminate) {
     DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
     // Wait for completed log buffers to exist.
     {
       MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
       while (((_worker_id == 0 && !dcqs.process_completed_buffers()) ||
               (_worker_id > 0 && !is_active())) &&
              !_should_terminate) {
          DirtyCardQ_CBL_mon->wait(Mutex::_no_safepoint_check_flag);
       }
     }
     if (_should_terminate) {
       return;
     }
     // Now we take them off (this doesn't hold locks while it applies
     // closures.)  (If we did a full collection, then we'll do a full
     // traversal.
     _sts.join();
     int n_logs = 0;
     int lower_limit = 0;
     double start_vtime_sec; // only used when G1SmoothConcRefine is on
     int prev_buffer_num; // only used when G1SmoothConcRefine is on
     // This thread activation threshold
     int threshold = G1UpdateBufferQueueProcessingThreshold * _worker_id;
     // Next thread activation threshold
     int next_threshold = threshold + G1UpdateBufferQueueProcessingThreshold;
     int deactivation_threshold = MAX2<int>(threshold - G1UpdateBufferQueueProcessingThreshold / 2, 0);
     if (G1SmoothConcRefine) {
       lower_limit = 0;
       start_vtime_sec = os::elapsedVTime();
       prev_buffer_num = (int) dcqs.completed_buffers_num();
     } else {
       lower_limit = G1UpdateBufferQueueProcessingThreshold / 4; // For now.
     }
     while (dcqs.apply_closure_to_completed_buffer(_worker_id + _worker_id_offset, lower_limit)) {
       double end_vtime_sec;
       double elapsed_vtime_sec;
       int elapsed_vtime_ms;
       int curr_buffer_num = (int) dcqs.completed_buffers_num();
       if (G1SmoothConcRefine) {
         end_vtime_sec = os::elapsedVTime();
         elapsed_vtime_sec = end_vtime_sec - start_vtime_sec;
         elapsed_vtime_ms = (int) (elapsed_vtime_sec * 1000.0);
         if (curr_buffer_num > prev_buffer_num ||
             curr_buffer_num > next_threshold) {
           decreaseInterval(elapsed_vtime_ms);
         } else if (curr_buffer_num < prev_buffer_num) {
           increaseInterval(elapsed_vtime_ms);
         }
       }
       if (_worker_id == 0) {
         sample_young_list_rs_lengths();
       } else if (curr_buffer_num < deactivation_threshold) {
         // If the number of the buffer has fallen below our threshold
         // we should deactivate. The predecessor will reactivate this
         // thread should the number of the buffers cross the threshold again.
         MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
         deactivate();
         if (G1TraceConcurrentRefinement) {
           gclog_or_tty->print_cr("G1-Refine-deactivated worker %d", _worker_id);
         }
         break;
       }
       _co_tracker.update(false);
       // Check if we need to activate the next thread.
       if (curr_buffer_num > next_threshold && _next != NULL && !_next->is_active()) {
         MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
         _next->activate();
         DirtyCardQ_CBL_mon->notify_all();
         if (G1TraceConcurrentRefinement) {
           gclog_or_tty->print_cr("G1-Refine-activated worker %d", _next->_worker_id);
         }
       }
       if (G1SmoothConcRefine) {
         prev_buffer_num = curr_buffer_num;
         _sts.leave();
         os::sleep(Thread::current(), (jlong) _interval_ms, false);
         _sts.join();
         start_vtime_sec = os::elapsedVTime();
       }
       n_logs++;
     }
     _co_tracker.update(false);
     _sts.leave();
     if (os::supports_vtime()) {
       _vtime_accum = (os::elapsedVTime() - _vtime_start);
     } else {
       _vtime_accum = 0.0;
     }
   }
   _sts.join();
   _co_tracker.update(true);
   _sts.leave();
   assert(_should_terminate, "just checking");
   terminate();
 }
 void ConcurrentG1RefineThread::yield() {
   if (G1TraceConcurrentRefinement) gclog_or_tty->print_cr("G1-Refine-yield");
   _sts.yield("G1 refine");
   if (G1TraceConcurrentRefinement) gclog_or_tty->print_cr("G1-Refine-yield-end");
 }
 void ConcurrentG1RefineThread::stop() {
   // it is ok to take late safepoints here, if needed
   {
     MutexLockerEx mu(Terminator_lock);
     _should_terminate = true;
   }
   {
     MutexLockerEx x(DirtyCardQ_CBL_mon, Mutex::_no_safepoint_check_flag);
     DirtyCardQ_CBL_mon->notify_all();
   }
   {
     MutexLockerEx mu(Terminator_lock);
     while (!_has_terminated) {
       Terminator_lock->wait();
     }
   }
   if (G1TraceConcurrentRefinement) gclog_or_tty->print_cr("G1-Refine-stop");
 }
 void ConcurrentG1RefineThread::print() {
   gclog_or_tty->print("\"Concurrent G1 Refinement Thread\" ");
   Thread::print();
   gclog_or_tty->cr();
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp@15c5903cf9e1 (annotated)

src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp