ffeb0bdad0
JEP-271. VM changes contributed by brutisso, test changes contributed by david. Co-authored-by: David Lindholm <david.lindholm@oralce.com> Reviewed-by: sjohanss, david, brutisso
632 lines
26 KiB
C++
632 lines
26 KiB
C++
/*
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* Copyright (c) 2004, 2016, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*
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*/
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#include "precompiled.hpp"
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#include "gc/shared/adaptiveSizePolicy.hpp"
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#include "gc/shared/collectorPolicy.hpp"
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#include "gc/shared/gcCause.hpp"
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#include "gc/shared/workgroup.hpp"
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#include "logging/log.hpp"
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#include "runtime/timer.hpp"
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#include "utilities/ostream.hpp"
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elapsedTimer AdaptiveSizePolicy::_minor_timer;
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elapsedTimer AdaptiveSizePolicy::_major_timer;
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bool AdaptiveSizePolicy::_debug_perturbation = false;
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// The throughput goal is implemented as
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// _throughput_goal = 1 - ( 1 / (1 + gc_cost_ratio))
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// gc_cost_ratio is the ratio
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// application cost / gc cost
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// For example a gc_cost_ratio of 4 translates into a
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// throughput goal of .80
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AdaptiveSizePolicy::AdaptiveSizePolicy(size_t init_eden_size,
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size_t init_promo_size,
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size_t init_survivor_size,
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double gc_pause_goal_sec,
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uint gc_cost_ratio) :
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_eden_size(init_eden_size),
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_promo_size(init_promo_size),
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_survivor_size(init_survivor_size),
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_gc_pause_goal_sec(gc_pause_goal_sec),
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_throughput_goal(1.0 - double(1.0 / (1.0 + (double) gc_cost_ratio))),
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_gc_overhead_limit_exceeded(false),
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_print_gc_overhead_limit_would_be_exceeded(false),
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_gc_overhead_limit_count(0),
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_latest_minor_mutator_interval_seconds(0),
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_threshold_tolerance_percent(1.0 + ThresholdTolerance/100.0),
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_young_gen_change_for_minor_throughput(0),
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_old_gen_change_for_major_throughput(0) {
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assert(AdaptiveSizePolicyGCTimeLimitThreshold > 0,
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"No opportunity to clear SoftReferences before GC overhead limit");
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_avg_minor_pause =
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new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding);
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_avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
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_avg_minor_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
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_avg_major_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
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_avg_young_live = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight);
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_avg_old_live = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight);
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_avg_eden_live = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight);
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_avg_survived = new AdaptivePaddedAverage(AdaptiveSizePolicyWeight,
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SurvivorPadding);
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_avg_pretenured = new AdaptivePaddedNoZeroDevAverage(
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AdaptiveSizePolicyWeight,
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SurvivorPadding);
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_minor_pause_old_estimator =
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new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
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_minor_pause_young_estimator =
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new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
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_minor_collection_estimator =
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new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
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_major_collection_estimator =
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new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
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// Start the timers
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_minor_timer.start();
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_young_gen_policy_is_ready = false;
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}
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// If the number of GC threads was set on the command line,
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// use it.
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// Else
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// Calculate the number of GC threads based on the number of Java threads.
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// Calculate the number of GC threads based on the size of the heap.
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// Use the larger.
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uint AdaptiveSizePolicy::calc_default_active_workers(uintx total_workers,
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const uintx min_workers,
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uintx active_workers,
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uintx application_workers) {
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// If the user has specifically set the number of
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// GC threads, use them.
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// If the user has turned off using a dynamic number of GC threads
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// or the users has requested a specific number, set the active
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// number of workers to all the workers.
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uintx new_active_workers = total_workers;
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uintx prev_active_workers = active_workers;
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uintx active_workers_by_JT = 0;
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uintx active_workers_by_heap_size = 0;
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// Always use at least min_workers but use up to
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// GCThreadsPerJavaThreads * application threads.
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active_workers_by_JT =
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MAX2((uintx) GCWorkersPerJavaThread * application_workers,
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min_workers);
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// Choose a number of GC threads based on the current size
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// of the heap. This may be complicated because the size of
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// the heap depends on factors such as the throughput goal.
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// Still a large heap should be collected by more GC threads.
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active_workers_by_heap_size =
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MAX2((size_t) 2U, Universe::heap()->capacity() / HeapSizePerGCThread);
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uintx max_active_workers =
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MAX2(active_workers_by_JT, active_workers_by_heap_size);
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new_active_workers = MIN2(max_active_workers, (uintx) total_workers);
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// Increase GC workers instantly but decrease them more
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// slowly.
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if (new_active_workers < prev_active_workers) {
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new_active_workers =
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MAX2(min_workers, (prev_active_workers + new_active_workers) / 2);
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}
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// Check once more that the number of workers is within the limits.
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assert(min_workers <= total_workers, "Minimum workers not consistent with total workers");
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assert(new_active_workers >= min_workers, "Minimum workers not observed");
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assert(new_active_workers <= total_workers, "Total workers not observed");
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if (ForceDynamicNumberOfGCThreads) {
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// Assume this is debugging and jiggle the number of GC threads.
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if (new_active_workers == prev_active_workers) {
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if (new_active_workers < total_workers) {
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new_active_workers++;
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} else if (new_active_workers > min_workers) {
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new_active_workers--;
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}
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}
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if (new_active_workers == total_workers) {
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if (_debug_perturbation) {
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new_active_workers = min_workers;
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}
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_debug_perturbation = !_debug_perturbation;
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}
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assert((new_active_workers <= ParallelGCThreads) &&
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(new_active_workers >= min_workers),
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"Jiggled active workers too much");
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}
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log_trace(gc, task)("GCTaskManager::calc_default_active_workers() : "
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"active_workers(): " UINTX_FORMAT " new_active_workers: " UINTX_FORMAT " "
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"prev_active_workers: " UINTX_FORMAT "\n"
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" active_workers_by_JT: " UINTX_FORMAT " active_workers_by_heap_size: " UINTX_FORMAT,
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active_workers, new_active_workers, prev_active_workers,
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active_workers_by_JT, active_workers_by_heap_size);
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assert(new_active_workers > 0, "Always need at least 1");
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return new_active_workers;
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}
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uint AdaptiveSizePolicy::calc_active_workers(uintx total_workers,
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uintx active_workers,
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uintx application_workers) {
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// If the user has specifically set the number of
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// GC threads, use them.
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// If the user has turned off using a dynamic number of GC threads
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// or the users has requested a specific number, set the active
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// number of workers to all the workers.
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uint new_active_workers;
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if (!UseDynamicNumberOfGCThreads ||
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(!FLAG_IS_DEFAULT(ParallelGCThreads) && !ForceDynamicNumberOfGCThreads)) {
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new_active_workers = total_workers;
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} else {
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uintx min_workers = (total_workers == 1) ? 1 : 2;
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new_active_workers = calc_default_active_workers(total_workers,
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min_workers,
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active_workers,
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application_workers);
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}
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assert(new_active_workers > 0, "Always need at least 1");
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return new_active_workers;
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}
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uint AdaptiveSizePolicy::calc_active_conc_workers(uintx total_workers,
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uintx active_workers,
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uintx application_workers) {
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if (!UseDynamicNumberOfGCThreads ||
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(!FLAG_IS_DEFAULT(ConcGCThreads) && !ForceDynamicNumberOfGCThreads)) {
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return ConcGCThreads;
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} else {
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uint no_of_gc_threads = calc_default_active_workers(total_workers,
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1, /* Minimum number of workers */
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active_workers,
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application_workers);
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return no_of_gc_threads;
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}
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}
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bool AdaptiveSizePolicy::tenuring_threshold_change() const {
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return decrement_tenuring_threshold_for_gc_cost() ||
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increment_tenuring_threshold_for_gc_cost() ||
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decrement_tenuring_threshold_for_survivor_limit();
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}
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void AdaptiveSizePolicy::minor_collection_begin() {
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// Update the interval time
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_minor_timer.stop();
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// Save most recent collection time
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_latest_minor_mutator_interval_seconds = _minor_timer.seconds();
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_minor_timer.reset();
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_minor_timer.start();
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}
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void AdaptiveSizePolicy::update_minor_pause_young_estimator(
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double minor_pause_in_ms) {
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double eden_size_in_mbytes = ((double)_eden_size)/((double)M);
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_minor_pause_young_estimator->update(eden_size_in_mbytes,
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minor_pause_in_ms);
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}
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void AdaptiveSizePolicy::minor_collection_end(GCCause::Cause gc_cause) {
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// Update the pause time.
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_minor_timer.stop();
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if (!GCCause::is_user_requested_gc(gc_cause) ||
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UseAdaptiveSizePolicyWithSystemGC) {
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double minor_pause_in_seconds = _minor_timer.seconds();
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double minor_pause_in_ms = minor_pause_in_seconds * MILLIUNITS;
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// Sample for performance counter
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_avg_minor_pause->sample(minor_pause_in_seconds);
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// Cost of collection (unit-less)
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double collection_cost = 0.0;
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if ((_latest_minor_mutator_interval_seconds > 0.0) &&
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(minor_pause_in_seconds > 0.0)) {
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double interval_in_seconds =
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_latest_minor_mutator_interval_seconds + minor_pause_in_seconds;
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collection_cost =
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minor_pause_in_seconds / interval_in_seconds;
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_avg_minor_gc_cost->sample(collection_cost);
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// Sample for performance counter
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_avg_minor_interval->sample(interval_in_seconds);
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}
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// The policy does not have enough data until at least some
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// young collections have been done.
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_young_gen_policy_is_ready =
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(_avg_minor_gc_cost->count() >= AdaptiveSizePolicyReadyThreshold);
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// Calculate variables used to estimate pause time vs. gen sizes
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double eden_size_in_mbytes = ((double)_eden_size) / ((double)M);
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update_minor_pause_young_estimator(minor_pause_in_ms);
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update_minor_pause_old_estimator(minor_pause_in_ms);
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log_trace(gc, ergo)("AdaptiveSizePolicy::minor_collection_end: minor gc cost: %f average: %f",
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collection_cost, _avg_minor_gc_cost->average());
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log_trace(gc, ergo)(" minor pause: %f minor period %f",
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minor_pause_in_ms, _latest_minor_mutator_interval_seconds * MILLIUNITS);
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// Calculate variable used to estimate collection cost vs. gen sizes
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assert(collection_cost >= 0.0, "Expected to be non-negative");
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_minor_collection_estimator->update(eden_size_in_mbytes, collection_cost);
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}
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// Interval times use this timer to measure the mutator time.
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// Reset the timer after the GC pause.
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_minor_timer.reset();
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_minor_timer.start();
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}
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size_t AdaptiveSizePolicy::eden_increment(size_t cur_eden, uint percent_change) {
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size_t eden_heap_delta;
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eden_heap_delta = cur_eden / 100 * percent_change;
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return eden_heap_delta;
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}
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size_t AdaptiveSizePolicy::eden_increment(size_t cur_eden) {
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return eden_increment(cur_eden, YoungGenerationSizeIncrement);
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}
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size_t AdaptiveSizePolicy::eden_decrement(size_t cur_eden) {
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size_t eden_heap_delta = eden_increment(cur_eden) /
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AdaptiveSizeDecrementScaleFactor;
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return eden_heap_delta;
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}
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size_t AdaptiveSizePolicy::promo_increment(size_t cur_promo, uint percent_change) {
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size_t promo_heap_delta;
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promo_heap_delta = cur_promo / 100 * percent_change;
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return promo_heap_delta;
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}
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size_t AdaptiveSizePolicy::promo_increment(size_t cur_promo) {
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return promo_increment(cur_promo, TenuredGenerationSizeIncrement);
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}
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size_t AdaptiveSizePolicy::promo_decrement(size_t cur_promo) {
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size_t promo_heap_delta = promo_increment(cur_promo);
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promo_heap_delta = promo_heap_delta / AdaptiveSizeDecrementScaleFactor;
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return promo_heap_delta;
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}
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double AdaptiveSizePolicy::time_since_major_gc() const {
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_major_timer.stop();
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double result = _major_timer.seconds();
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_major_timer.start();
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return result;
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}
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// Linear decay of major gc cost
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double AdaptiveSizePolicy::decaying_major_gc_cost() const {
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double major_interval = major_gc_interval_average_for_decay();
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double major_gc_cost_average = major_gc_cost();
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double decayed_major_gc_cost = major_gc_cost_average;
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if(time_since_major_gc() > 0.0) {
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decayed_major_gc_cost = major_gc_cost() *
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(((double) AdaptiveSizeMajorGCDecayTimeScale) * major_interval)
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/ time_since_major_gc();
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}
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// The decayed cost should always be smaller than the
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// average cost but the vagaries of finite arithmetic could
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// produce a larger value in decayed_major_gc_cost so protect
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// against that.
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return MIN2(major_gc_cost_average, decayed_major_gc_cost);
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}
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// Use a value of the major gc cost that has been decayed
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// by the factor
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//
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// average-interval-between-major-gc * AdaptiveSizeMajorGCDecayTimeScale /
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// time-since-last-major-gc
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//
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// if the average-interval-between-major-gc * AdaptiveSizeMajorGCDecayTimeScale
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// is less than time-since-last-major-gc.
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//
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// In cases where there are initial major gc's that
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// are of a relatively high cost but no later major
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// gc's, the total gc cost can remain high because
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// the major gc cost remains unchanged (since there are no major
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// gc's). In such a situation the value of the unchanging
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// major gc cost can keep the mutator throughput below
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// the goal when in fact the major gc cost is becoming diminishingly
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// small. Use the decaying gc cost only to decide whether to
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// adjust for throughput. Using it also to determine the adjustment
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// to be made for throughput also seems reasonable but there is
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// no test case to use to decide if it is the right thing to do
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// don't do it yet.
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double AdaptiveSizePolicy::decaying_gc_cost() const {
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double decayed_major_gc_cost = major_gc_cost();
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double avg_major_interval = major_gc_interval_average_for_decay();
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if (UseAdaptiveSizeDecayMajorGCCost &&
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(AdaptiveSizeMajorGCDecayTimeScale > 0) &&
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(avg_major_interval > 0.00)) {
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double time_since_last_major_gc = time_since_major_gc();
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// Decay the major gc cost?
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if (time_since_last_major_gc >
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((double) AdaptiveSizeMajorGCDecayTimeScale) * avg_major_interval) {
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// Decay using the time-since-last-major-gc
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decayed_major_gc_cost = decaying_major_gc_cost();
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log_trace(gc, ergo)("decaying_gc_cost: major interval average: %f time since last major gc: %f",
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avg_major_interval, time_since_last_major_gc);
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log_trace(gc, ergo)(" major gc cost: %f decayed major gc cost: %f",
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major_gc_cost(), decayed_major_gc_cost);
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}
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}
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double result = MIN2(1.0, decayed_major_gc_cost + minor_gc_cost());
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return result;
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}
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void AdaptiveSizePolicy::clear_generation_free_space_flags() {
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set_change_young_gen_for_min_pauses(0);
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set_change_old_gen_for_maj_pauses(0);
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set_change_old_gen_for_throughput(0);
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set_change_young_gen_for_throughput(0);
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set_decrease_for_footprint(0);
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set_decide_at_full_gc(0);
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}
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void AdaptiveSizePolicy::check_gc_overhead_limit(
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size_t young_live,
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size_t eden_live,
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size_t max_old_gen_size,
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size_t max_eden_size,
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bool is_full_gc,
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GCCause::Cause gc_cause,
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CollectorPolicy* collector_policy) {
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// Ignore explicit GC's. Exiting here does not set the flag and
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// does not reset the count. Updating of the averages for system
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// GC's is still controlled by UseAdaptiveSizePolicyWithSystemGC.
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if (GCCause::is_user_requested_gc(gc_cause) ||
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GCCause::is_serviceability_requested_gc(gc_cause)) {
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return;
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}
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// eden_limit is the upper limit on the size of eden based on
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// the maximum size of the young generation and the sizes
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// of the survivor space.
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// The question being asked is whether the gc costs are high
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// and the space being recovered by a collection is low.
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// free_in_young_gen is the free space in the young generation
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// after a collection and promo_live is the free space in the old
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// generation after a collection.
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//
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// Use the minimum of the current value of the live in the
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// young gen or the average of the live in the young gen.
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// If the current value drops quickly, that should be taken
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// into account (i.e., don't trigger if the amount of free
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// space has suddenly jumped up). If the current is much
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// higher than the average, use the average since it represents
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// the longer term behavior.
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const size_t live_in_eden =
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MIN2(eden_live, (size_t) avg_eden_live()->average());
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const size_t free_in_eden = max_eden_size > live_in_eden ?
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max_eden_size - live_in_eden : 0;
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const size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
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const size_t total_free_limit = free_in_old_gen + free_in_eden;
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const size_t total_mem = max_old_gen_size + max_eden_size;
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const double mem_free_limit = total_mem * (GCHeapFreeLimit/100.0);
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const double mem_free_old_limit = max_old_gen_size * (GCHeapFreeLimit/100.0);
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const double mem_free_eden_limit = max_eden_size * (GCHeapFreeLimit/100.0);
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const double gc_cost_limit = GCTimeLimit/100.0;
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size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average());
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// But don't force a promo size below the current promo size. Otherwise,
|
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// the promo size will shrink for no good reason.
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promo_limit = MAX2(promo_limit, _promo_size);
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|
|
|
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log_trace(gc, ergo)(
|
|
"PSAdaptiveSizePolicy::check_gc_overhead_limit:"
|
|
" promo_limit: " SIZE_FORMAT
|
|
" max_eden_size: " SIZE_FORMAT
|
|
" total_free_limit: " SIZE_FORMAT
|
|
" max_old_gen_size: " SIZE_FORMAT
|
|
" max_eden_size: " SIZE_FORMAT
|
|
" mem_free_limit: " SIZE_FORMAT,
|
|
promo_limit, max_eden_size, total_free_limit,
|
|
max_old_gen_size, max_eden_size,
|
|
(size_t) mem_free_limit);
|
|
|
|
bool print_gc_overhead_limit_would_be_exceeded = false;
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|
if (is_full_gc) {
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|
if (gc_cost() > gc_cost_limit &&
|
|
free_in_old_gen < (size_t) mem_free_old_limit &&
|
|
free_in_eden < (size_t) mem_free_eden_limit) {
|
|
// Collections, on average, are taking too much time, and
|
|
// gc_cost() > gc_cost_limit
|
|
// we have too little space available after a full gc.
|
|
// total_free_limit < mem_free_limit
|
|
// where
|
|
// total_free_limit is the free space available in
|
|
// both generations
|
|
// total_mem is the total space available for allocation
|
|
// in both generations (survivor spaces are not included
|
|
// just as they are not included in eden_limit).
|
|
// mem_free_limit is a fraction of total_mem judged to be an
|
|
// acceptable amount that is still unused.
|
|
// The heap can ask for the value of this variable when deciding
|
|
// whether to thrown an OutOfMemory error.
|
|
// Note that the gc time limit test only works for the collections
|
|
// of the young gen + tenured gen and not for collections of the
|
|
// permanent gen. That is because the calculation of the space
|
|
// freed by the collection is the free space in the young gen +
|
|
// tenured gen.
|
|
// At this point the GC overhead limit is being exceeded.
|
|
inc_gc_overhead_limit_count();
|
|
if (UseGCOverheadLimit) {
|
|
if (gc_overhead_limit_count() >=
|
|
AdaptiveSizePolicyGCTimeLimitThreshold){
|
|
// All conditions have been met for throwing an out-of-memory
|
|
set_gc_overhead_limit_exceeded(true);
|
|
// Avoid consecutive OOM due to the gc time limit by resetting
|
|
// the counter.
|
|
reset_gc_overhead_limit_count();
|
|
} else {
|
|
// The required consecutive collections which exceed the
|
|
// GC time limit may or may not have been reached. We
|
|
// are approaching that condition and so as not to
|
|
// throw an out-of-memory before all SoftRef's have been
|
|
// cleared, set _should_clear_all_soft_refs in CollectorPolicy.
|
|
// The clearing will be done on the next GC.
|
|
bool near_limit = gc_overhead_limit_near();
|
|
if (near_limit) {
|
|
collector_policy->set_should_clear_all_soft_refs(true);
|
|
log_trace(gc, ergo)("Nearing GC overhead limit, will be clearing all SoftReference");
|
|
}
|
|
}
|
|
}
|
|
// Set this even when the overhead limit will not
|
|
// cause an out-of-memory. Diagnostic message indicating
|
|
// that the overhead limit is being exceeded is sometimes
|
|
// printed.
|
|
print_gc_overhead_limit_would_be_exceeded = true;
|
|
|
|
} else {
|
|
// Did not exceed overhead limits
|
|
reset_gc_overhead_limit_count();
|
|
}
|
|
}
|
|
|
|
if (UseGCOverheadLimit) {
|
|
if (gc_overhead_limit_exceeded()) {
|
|
log_trace(gc, ergo)("GC is exceeding overhead limit of " UINTX_FORMAT "%%", GCTimeLimit);
|
|
reset_gc_overhead_limit_count();
|
|
} else if (print_gc_overhead_limit_would_be_exceeded) {
|
|
assert(gc_overhead_limit_count() > 0, "Should not be printing");
|
|
log_trace(gc, ergo)("GC would exceed overhead limit of " UINTX_FORMAT "%% %d consecutive time(s)",
|
|
GCTimeLimit, gc_overhead_limit_count());
|
|
}
|
|
}
|
|
}
|
|
// Printing
|
|
|
|
bool AdaptiveSizePolicy::print() const {
|
|
assert(UseAdaptiveSizePolicy, "UseAdaptiveSizePolicy need to be enabled.");
|
|
|
|
if (!log_is_enabled(Debug, gc, ergo)) {
|
|
return false;
|
|
}
|
|
|
|
// Print goal for which action is needed.
|
|
char* action = NULL;
|
|
bool change_for_pause = false;
|
|
if ((change_old_gen_for_maj_pauses() ==
|
|
decrease_old_gen_for_maj_pauses_true) ||
|
|
(change_young_gen_for_min_pauses() ==
|
|
decrease_young_gen_for_min_pauses_true)) {
|
|
action = (char*) " *** pause time goal ***";
|
|
change_for_pause = true;
|
|
} else if ((change_old_gen_for_throughput() ==
|
|
increase_old_gen_for_throughput_true) ||
|
|
(change_young_gen_for_throughput() ==
|
|
increase_young_gen_for_througput_true)) {
|
|
action = (char*) " *** throughput goal ***";
|
|
} else if (decrease_for_footprint()) {
|
|
action = (char*) " *** reduced footprint ***";
|
|
} else {
|
|
// No actions were taken. This can legitimately be the
|
|
// situation if not enough data has been gathered to make
|
|
// decisions.
|
|
return false;
|
|
}
|
|
|
|
// Pauses
|
|
// Currently the size of the old gen is only adjusted to
|
|
// change the major pause times.
|
|
char* young_gen_action = NULL;
|
|
char* tenured_gen_action = NULL;
|
|
|
|
char* shrink_msg = (char*) "(attempted to shrink)";
|
|
char* grow_msg = (char*) "(attempted to grow)";
|
|
char* no_change_msg = (char*) "(no change)";
|
|
if (change_young_gen_for_min_pauses() ==
|
|
decrease_young_gen_for_min_pauses_true) {
|
|
young_gen_action = shrink_msg;
|
|
} else if (change_for_pause) {
|
|
young_gen_action = no_change_msg;
|
|
}
|
|
|
|
if (change_old_gen_for_maj_pauses() == decrease_old_gen_for_maj_pauses_true) {
|
|
tenured_gen_action = shrink_msg;
|
|
} else if (change_for_pause) {
|
|
tenured_gen_action = no_change_msg;
|
|
}
|
|
|
|
// Throughput
|
|
if (change_old_gen_for_throughput() == increase_old_gen_for_throughput_true) {
|
|
assert(change_young_gen_for_throughput() ==
|
|
increase_young_gen_for_througput_true,
|
|
"Both generations should be growing");
|
|
young_gen_action = grow_msg;
|
|
tenured_gen_action = grow_msg;
|
|
} else if (change_young_gen_for_throughput() ==
|
|
increase_young_gen_for_througput_true) {
|
|
// Only the young generation may grow at start up (before
|
|
// enough full collections have been done to grow the old generation).
|
|
young_gen_action = grow_msg;
|
|
tenured_gen_action = no_change_msg;
|
|
}
|
|
|
|
// Minimum footprint
|
|
if (decrease_for_footprint() != 0) {
|
|
young_gen_action = shrink_msg;
|
|
tenured_gen_action = shrink_msg;
|
|
}
|
|
|
|
log_debug(gc, ergo)("UseAdaptiveSizePolicy actions to meet %s", action);
|
|
log_debug(gc, ergo)(" GC overhead (%%)");
|
|
log_debug(gc, ergo)(" Young generation: %7.2f\t %s",
|
|
100.0 * avg_minor_gc_cost()->average(), young_gen_action);
|
|
log_debug(gc, ergo)(" Tenured generation: %7.2f\t %s",
|
|
100.0 * avg_major_gc_cost()->average(), tenured_gen_action);
|
|
return true;
|
|
}
|
|
|
|
void AdaptiveSizePolicy::print_tenuring_threshold( uint new_tenuring_threshold_arg) const {
|
|
// Tenuring threshold
|
|
if (decrement_tenuring_threshold_for_survivor_limit()) {
|
|
log_debug(gc, ergo)("Tenuring threshold: (attempted to decrease to avoid survivor space overflow) = %u", new_tenuring_threshold_arg);
|
|
} else if (decrement_tenuring_threshold_for_gc_cost()) {
|
|
log_debug(gc, ergo)("Tenuring threshold: (attempted to decrease to balance GC costs) = %u", new_tenuring_threshold_arg);
|
|
} else if (increment_tenuring_threshold_for_gc_cost()) {
|
|
log_debug(gc, ergo)("Tenuring threshold: (attempted to increase to balance GC costs) = %u", new_tenuring_threshold_arg);
|
|
} else {
|
|
assert(!tenuring_threshold_change(), "(no change was attempted)");
|
|
}
|
|
}
|