Mercurial > hg > graal-compiler
view src/share/vm/utilities/taskqueue.cpp @ 616:4f360ec815ba
6720309: G1: don't synchronously update RSet during evacuation pauses
6720334: G1: don't update RSets of collection set regions during an evacuation pause
Summary: Introduced a deferred update mechanism for delaying the rset updates during the collection pause
Reviewed-by: apetrusenko, tonyp
author | iveresov |
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date | Fri, 06 Mar 2009 13:50:14 -0800 |
parents | 05c6d52fa7a9 |
children | 0fbdb4381b99 |
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/* * Copyright 2001-2008 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/_taskqueue.cpp.incl" #ifdef TRACESPINNING uint ParallelTaskTerminator::_total_yields = 0; uint ParallelTaskTerminator::_total_spins = 0; uint ParallelTaskTerminator::_total_peeks = 0; #endif bool TaskQueueSuper::peek() { return _bottom != _age.top(); } int TaskQueueSetSuper::randomParkAndMiller(int *seed0) { const int a = 16807; const int m = 2147483647; const int q = 127773; /* m div a */ const int r = 2836; /* m mod a */ assert(sizeof(int) == 4, "I think this relies on that"); int seed = *seed0; int hi = seed / q; int lo = seed % q; int test = a * lo - r * hi; if (test > 0) seed = test; else seed = test + m; *seed0 = seed; return seed; } ParallelTaskTerminator:: ParallelTaskTerminator(int n_threads, TaskQueueSetSuper* queue_set) : _n_threads(n_threads), _queue_set(queue_set), _offered_termination(0) {} bool ParallelTaskTerminator::peek_in_queue_set() { return _queue_set->peek(); } void ParallelTaskTerminator::yield() { os::yield(); } void ParallelTaskTerminator::sleep(uint millis) { os::sleep(Thread::current(), millis, false); } bool ParallelTaskTerminator::offer_termination(TerminatorTerminator* terminator) { Atomic::inc(&_offered_termination); uint yield_count = 0; // Number of hard spin loops done since last yield uint hard_spin_count = 0; // Number of iterations in the hard spin loop. uint hard_spin_limit = WorkStealingHardSpins; // If WorkStealingSpinToYieldRatio is 0, no hard spinning is done. // If it is greater than 0, then start with a small number // of spins and increase number with each turn at spinning until // the count of hard spins exceeds WorkStealingSpinToYieldRatio. // Then do a yield() call and start spinning afresh. if (WorkStealingSpinToYieldRatio > 0) { hard_spin_limit = WorkStealingHardSpins >> WorkStealingSpinToYieldRatio; hard_spin_limit = MAX2(hard_spin_limit, 1U); } // Remember the initial spin limit. uint hard_spin_start = hard_spin_limit; // Loop waiting for all threads to offer termination or // more work. while (true) { // Are all threads offering termination? if (_offered_termination == _n_threads) { return true; } else { // Look for more work. // Periodically sleep() instead of yield() to give threads // waiting on the cores the chance to grab this code if (yield_count <= WorkStealingYieldsBeforeSleep) { // Do a yield or hardspin. For purposes of deciding whether // to sleep, count this as a yield. yield_count++; // Periodically call yield() instead spinning // After WorkStealingSpinToYieldRatio spins, do a yield() call // and reset the counts and starting limit. if (hard_spin_count > WorkStealingSpinToYieldRatio) { yield(); hard_spin_count = 0; hard_spin_limit = hard_spin_start; #ifdef TRACESPINNING _total_yields++; #endif } else { // Hard spin this time // Increase the hard spinning period but only up to a limit. hard_spin_limit = MIN2(2*hard_spin_limit, (uint) WorkStealingHardSpins); for (uint j = 0; j < hard_spin_limit; j++) { SpinPause(); } hard_spin_count++; #ifdef TRACESPINNING _total_spins++; #endif } } else { if (PrintGCDetails && Verbose) { gclog_or_tty->print_cr("ParallelTaskTerminator::offer_termination() " "thread %d sleeps after %d yields", Thread::current(), yield_count); } yield_count = 0; // A sleep will cause this processor to seek work on another processor's // runqueue, if it has nothing else to run (as opposed to the yield // which may only move the thread to the end of the this processor's // runqueue). sleep(WorkStealingSleepMillis); } #ifdef TRACESPINNING _total_peeks++; #endif if (peek_in_queue_set() || (terminator != NULL && terminator->should_exit_termination())) { Atomic::dec(&_offered_termination); return false; } } } } #ifdef TRACESPINNING void ParallelTaskTerminator::print_termination_counts() { gclog_or_tty->print_cr("ParallelTaskTerminator Total yields: %lld " "Total spins: %lld Total peeks: %lld", total_yields(), total_spins(), total_peeks()); } #endif void ParallelTaskTerminator::reset_for_reuse() { if (_offered_termination != 0) { assert(_offered_termination == _n_threads, "Terminator may still be in use"); _offered_termination = 0; } } bool RegionTaskQueueWithOverflow::is_empty() { return (_region_queue.size() == 0) && (_overflow_stack->length() == 0); } bool RegionTaskQueueWithOverflow::stealable_is_empty() { return _region_queue.size() == 0; } bool RegionTaskQueueWithOverflow::overflow_is_empty() { return _overflow_stack->length() == 0; } void RegionTaskQueueWithOverflow::initialize() { _region_queue.initialize(); assert(_overflow_stack == 0, "Creating memory leak"); _overflow_stack = new (ResourceObj::C_HEAP) GrowableArray<RegionTask>(10, true); } void RegionTaskQueueWithOverflow::save(RegionTask t) { if (TraceRegionTasksQueuing && Verbose) { gclog_or_tty->print_cr("CTQ: save " PTR_FORMAT, t); } if(!_region_queue.push(t)) { _overflow_stack->push(t); } } // Note that using this method will retrieve all regions // that have been saved but that it will always check // the overflow stack. It may be more efficient to // check the stealable queue and the overflow stack // separately. bool RegionTaskQueueWithOverflow::retrieve(RegionTask& region_task) { bool result = retrieve_from_overflow(region_task); if (!result) { result = retrieve_from_stealable_queue(region_task); } if (TraceRegionTasksQueuing && Verbose && result) { gclog_or_tty->print_cr(" CTQ: retrieve " PTR_FORMAT, result); } return result; } bool RegionTaskQueueWithOverflow::retrieve_from_stealable_queue( RegionTask& region_task) { bool result = _region_queue.pop_local(region_task); if (TraceRegionTasksQueuing && Verbose) { gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, region_task); } return result; } bool RegionTaskQueueWithOverflow::retrieve_from_overflow(RegionTask& region_task) { bool result; if (!_overflow_stack->is_empty()) { region_task = _overflow_stack->pop(); result = true; } else { region_task = (RegionTask) NULL; result = false; } if (TraceRegionTasksQueuing && Verbose) { gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, region_task); } return result; }