| /* |
| * Copyright (c) 2004, 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/shared/adaptiveSizePolicy.hpp" |
| #include "gc_interface/gcCause.hpp" |
| #include "memory/collectorPolicy.hpp" |
| #include "runtime/timer.hpp" |
| #include "utilities/ostream.hpp" |
| #include "utilities/workgroup.hpp" |
| elapsedTimer AdaptiveSizePolicy::_minor_timer; |
| elapsedTimer AdaptiveSizePolicy::_major_timer; |
| bool AdaptiveSizePolicy::_debug_perturbation = false; |
| |
| // The throughput goal is implemented as |
| // _throughput_goal = 1 - ( 1 / (1 + gc_cost_ratio)) |
| // gc_cost_ratio is the ratio |
| // application cost / gc cost |
| // For example a gc_cost_ratio of 4 translates into a |
| // throughput goal of .80 |
| |
| AdaptiveSizePolicy::AdaptiveSizePolicy(size_t init_eden_size, |
| size_t init_promo_size, |
| size_t init_survivor_size, |
| double gc_pause_goal_sec, |
| uint gc_cost_ratio) : |
| _eden_size(init_eden_size), |
| _promo_size(init_promo_size), |
| _survivor_size(init_survivor_size), |
| _gc_pause_goal_sec(gc_pause_goal_sec), |
| _throughput_goal(1.0 - double(1.0 / (1.0 + (double) gc_cost_ratio))), |
| _gc_overhead_limit_exceeded(false), |
| _print_gc_overhead_limit_would_be_exceeded(false), |
| _gc_overhead_limit_count(0), |
| _latest_minor_mutator_interval_seconds(0), |
| _threshold_tolerance_percent(1.0 + ThresholdTolerance/100.0), |
| _young_gen_change_for_minor_throughput(0), |
| _old_gen_change_for_major_throughput(0) { |
| assert(AdaptiveSizePolicyGCTimeLimitThreshold > 0, |
| "No opportunity to clear SoftReferences before GC overhead limit"); |
| _avg_minor_pause = |
| new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding); |
| _avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); |
| _avg_minor_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); |
| _avg_major_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); |
| |
| _avg_young_live = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight); |
| _avg_old_live = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight); |
| _avg_eden_live = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight); |
| |
| _avg_survived = new AdaptivePaddedAverage(AdaptiveSizePolicyWeight, |
| SurvivorPadding); |
| _avg_pretenured = new AdaptivePaddedNoZeroDevAverage( |
| AdaptiveSizePolicyWeight, |
| SurvivorPadding); |
| |
| _minor_pause_old_estimator = |
| new LinearLeastSquareFit(AdaptiveSizePolicyWeight); |
| _minor_pause_young_estimator = |
| new LinearLeastSquareFit(AdaptiveSizePolicyWeight); |
| _minor_collection_estimator = |
| new LinearLeastSquareFit(AdaptiveSizePolicyWeight); |
| _major_collection_estimator = |
| new LinearLeastSquareFit(AdaptiveSizePolicyWeight); |
| |
| // Start the timers |
| _minor_timer.start(); |
| |
| _young_gen_policy_is_ready = false; |
| } |
| |
| // If the number of GC threads was set on the command line, |
| // use it. |
| // Else |
| // Calculate the number of GC threads based on the number of Java threads. |
| // Calculate the number of GC threads based on the size of the heap. |
| // Use the larger. |
| |
| int AdaptiveSizePolicy::calc_default_active_workers(uintx total_workers, |
| const uintx min_workers, |
| uintx active_workers, |
| uintx application_workers) { |
| // If the user has specifically set the number of |
| // GC threads, use them. |
| |
| // If the user has turned off using a dynamic number of GC threads |
| // or the users has requested a specific number, set the active |
| // number of workers to all the workers. |
| |
| uintx new_active_workers = total_workers; |
| uintx prev_active_workers = active_workers; |
| uintx active_workers_by_JT = 0; |
| uintx active_workers_by_heap_size = 0; |
| |
| // Always use at least min_workers but use up to |
| // GCThreadsPerJavaThreads * application threads. |
| active_workers_by_JT = |
| MAX2((uintx) GCWorkersPerJavaThread * application_workers, |
| min_workers); |
| |
| // Choose a number of GC threads based on the current size |
| // of the heap. This may be complicated because the size of |
| // the heap depends on factors such as the thoughput goal. |
| // Still a large heap should be collected by more GC threads. |
| active_workers_by_heap_size = |
| MAX2((size_t) 2U, Universe::heap()->capacity() / HeapSizePerGCThread); |
| |
| uintx max_active_workers = |
| MAX2(active_workers_by_JT, active_workers_by_heap_size); |
| |
| // Limit the number of workers to the the number created, |
| // (workers()). |
| new_active_workers = MIN2(max_active_workers, |
| (uintx) total_workers); |
| |
| // Increase GC workers instantly but decrease them more |
| // slowly. |
| if (new_active_workers < prev_active_workers) { |
| new_active_workers = |
| MAX2(min_workers, (prev_active_workers + new_active_workers) / 2); |
| } |
| |
| // Check once more that the number of workers is within the limits. |
| assert(min_workers <= total_workers, "Minimum workers not consistent with total workers"); |
| assert(new_active_workers >= min_workers, "Minimum workers not observed"); |
| assert(new_active_workers <= total_workers, "Total workers not observed"); |
| |
| if (ForceDynamicNumberOfGCThreads) { |
| // Assume this is debugging and jiggle the number of GC threads. |
| if (new_active_workers == prev_active_workers) { |
| if (new_active_workers < total_workers) { |
| new_active_workers++; |
| } else if (new_active_workers > min_workers) { |
| new_active_workers--; |
| } |
| } |
| if (new_active_workers == total_workers) { |
| if (_debug_perturbation) { |
| new_active_workers = min_workers; |
| } |
| _debug_perturbation = !_debug_perturbation; |
| } |
| assert((new_active_workers <= (uintx) ParallelGCThreads) && |
| (new_active_workers >= min_workers), |
| "Jiggled active workers too much"); |
| } |
| |
| if (TraceDynamicGCThreads) { |
| gclog_or_tty->print_cr("GCTaskManager::calc_default_active_workers() : " |
| "active_workers(): %d new_active_workers: %d " |
| "prev_active_workers: %d\n" |
| " active_workers_by_JT: %d active_workers_by_heap_size: %d", |
| (int) active_workers, (int) new_active_workers, (int) prev_active_workers, |
| (int) active_workers_by_JT, (int) active_workers_by_heap_size); |
| } |
| assert(new_active_workers > 0, "Always need at least 1"); |
| return new_active_workers; |
| } |
| |
| int AdaptiveSizePolicy::calc_active_workers(uintx total_workers, |
| uintx active_workers, |
| uintx application_workers) { |
| // If the user has specifically set the number of |
| // GC threads, use them. |
| |
| // If the user has turned off using a dynamic number of GC threads |
| // or the users has requested a specific number, set the active |
| // number of workers to all the workers. |
| |
| int new_active_workers; |
| if (!UseDynamicNumberOfGCThreads || |
| (!FLAG_IS_DEFAULT(ParallelGCThreads) && !ForceDynamicNumberOfGCThreads)) { |
| new_active_workers = total_workers; |
| } else { |
| uintx min_workers = (total_workers == 1) ? 1 : 2; |
| new_active_workers = calc_default_active_workers(total_workers, |
| min_workers, |
| active_workers, |
| application_workers); |
| } |
| assert(new_active_workers > 0, "Always need at least 1"); |
| return new_active_workers; |
| } |
| |
| int AdaptiveSizePolicy::calc_active_conc_workers(uintx total_workers, |
| uintx active_workers, |
| uintx application_workers) { |
| if (!UseDynamicNumberOfGCThreads || |
| (!FLAG_IS_DEFAULT(ConcGCThreads) && !ForceDynamicNumberOfGCThreads)) { |
| return ConcGCThreads; |
| } else { |
| int no_of_gc_threads = calc_default_active_workers( |
| total_workers, |
| 1, /* Minimum number of workers */ |
| active_workers, |
| application_workers); |
| return no_of_gc_threads; |
| } |
| } |
| |
| bool AdaptiveSizePolicy::tenuring_threshold_change() const { |
| return decrement_tenuring_threshold_for_gc_cost() || |
| increment_tenuring_threshold_for_gc_cost() || |
| decrement_tenuring_threshold_for_survivor_limit(); |
| } |
| |
| void AdaptiveSizePolicy::minor_collection_begin() { |
| // Update the interval time |
| _minor_timer.stop(); |
| // Save most recent collection time |
| _latest_minor_mutator_interval_seconds = _minor_timer.seconds(); |
| _minor_timer.reset(); |
| _minor_timer.start(); |
| } |
| |
| void AdaptiveSizePolicy::update_minor_pause_young_estimator( |
| double minor_pause_in_ms) { |
| double eden_size_in_mbytes = ((double)_eden_size)/((double)M); |
| _minor_pause_young_estimator->update(eden_size_in_mbytes, |
| minor_pause_in_ms); |
| } |
| |
| void AdaptiveSizePolicy::minor_collection_end(GCCause::Cause gc_cause) { |
| // Update the pause time. |
| _minor_timer.stop(); |
| |
| if (gc_cause != GCCause::_java_lang_system_gc || |
| UseAdaptiveSizePolicyWithSystemGC) { |
| double minor_pause_in_seconds = _minor_timer.seconds(); |
| double minor_pause_in_ms = minor_pause_in_seconds * MILLIUNITS; |
| |
| // Sample for performance counter |
| _avg_minor_pause->sample(minor_pause_in_seconds); |
| |
| // Cost of collection (unit-less) |
| double collection_cost = 0.0; |
| if ((_latest_minor_mutator_interval_seconds > 0.0) && |
| (minor_pause_in_seconds > 0.0)) { |
| double interval_in_seconds = |
| _latest_minor_mutator_interval_seconds + minor_pause_in_seconds; |
| collection_cost = |
| minor_pause_in_seconds / interval_in_seconds; |
| _avg_minor_gc_cost->sample(collection_cost); |
| // Sample for performance counter |
| _avg_minor_interval->sample(interval_in_seconds); |
| } |
| |
| // The policy does not have enough data until at least some |
| // minor collections have been done. |
| _young_gen_policy_is_ready = |
| (_avg_minor_gc_cost->count() >= AdaptiveSizePolicyReadyThreshold); |
| |
| // Calculate variables used to estimate pause time vs. gen sizes |
| double eden_size_in_mbytes = ((double)_eden_size)/((double)M); |
| update_minor_pause_young_estimator(minor_pause_in_ms); |
| update_minor_pause_old_estimator(minor_pause_in_ms); |
| |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print("AdaptiveSizePolicy::minor_collection_end: " |
| "minor gc cost: %f average: %f", collection_cost, |
| _avg_minor_gc_cost->average()); |
| gclog_or_tty->print_cr(" minor pause: %f minor period %f", |
| minor_pause_in_ms, |
| _latest_minor_mutator_interval_seconds * MILLIUNITS); |
| } |
| |
| // Calculate variable used to estimate collection cost vs. gen sizes |
| assert(collection_cost >= 0.0, "Expected to be non-negative"); |
| _minor_collection_estimator->update(eden_size_in_mbytes, collection_cost); |
| } |
| |
| // Interval times use this timer to measure the mutator time. |
| // Reset the timer after the GC pause. |
| _minor_timer.reset(); |
| _minor_timer.start(); |
| } |
| |
| size_t AdaptiveSizePolicy::eden_increment(size_t cur_eden, |
| uint percent_change) { |
| size_t eden_heap_delta; |
| eden_heap_delta = cur_eden / 100 * percent_change; |
| return eden_heap_delta; |
| } |
| |
| size_t AdaptiveSizePolicy::eden_increment(size_t cur_eden) { |
| return eden_increment(cur_eden, YoungGenerationSizeIncrement); |
| } |
| |
| size_t AdaptiveSizePolicy::eden_decrement(size_t cur_eden) { |
| size_t eden_heap_delta = eden_increment(cur_eden) / |
| AdaptiveSizeDecrementScaleFactor; |
| return eden_heap_delta; |
| } |
| |
| size_t AdaptiveSizePolicy::promo_increment(size_t cur_promo, |
| uint percent_change) { |
| size_t promo_heap_delta; |
| promo_heap_delta = cur_promo / 100 * percent_change; |
| return promo_heap_delta; |
| } |
| |
| size_t AdaptiveSizePolicy::promo_increment(size_t cur_promo) { |
| return promo_increment(cur_promo, TenuredGenerationSizeIncrement); |
| } |
| |
| size_t AdaptiveSizePolicy::promo_decrement(size_t cur_promo) { |
| size_t promo_heap_delta = promo_increment(cur_promo); |
| promo_heap_delta = promo_heap_delta / AdaptiveSizeDecrementScaleFactor; |
| return promo_heap_delta; |
| } |
| |
| double AdaptiveSizePolicy::time_since_major_gc() const { |
| _major_timer.stop(); |
| double result = _major_timer.seconds(); |
| _major_timer.start(); |
| return result; |
| } |
| |
| // Linear decay of major gc cost |
| double AdaptiveSizePolicy::decaying_major_gc_cost() const { |
| double major_interval = major_gc_interval_average_for_decay(); |
| double major_gc_cost_average = major_gc_cost(); |
| double decayed_major_gc_cost = major_gc_cost_average; |
| if(time_since_major_gc() > 0.0) { |
| decayed_major_gc_cost = major_gc_cost() * |
| (((double) AdaptiveSizeMajorGCDecayTimeScale) * major_interval) |
| / time_since_major_gc(); |
| } |
| |
| // The decayed cost should always be smaller than the |
| // average cost but the vagaries of finite arithmetic could |
| // produce a larger value in decayed_major_gc_cost so protect |
| // against that. |
| return MIN2(major_gc_cost_average, decayed_major_gc_cost); |
| } |
| |
| // Use a value of the major gc cost that has been decayed |
| // by the factor |
| // |
| // average-interval-between-major-gc * AdaptiveSizeMajorGCDecayTimeScale / |
| // time-since-last-major-gc |
| // |
| // if the average-interval-between-major-gc * AdaptiveSizeMajorGCDecayTimeScale |
| // is less than time-since-last-major-gc. |
| // |
| // In cases where there are initial major gc's that |
| // are of a relatively high cost but no later major |
| // gc's, the total gc cost can remain high because |
| // the major gc cost remains unchanged (since there are no major |
| // gc's). In such a situation the value of the unchanging |
| // major gc cost can keep the mutator throughput below |
| // the goal when in fact the major gc cost is becoming diminishingly |
| // small. Use the decaying gc cost only to decide whether to |
| // adjust for throughput. Using it also to determine the adjustment |
| // to be made for throughput also seems reasonable but there is |
| // no test case to use to decide if it is the right thing to do |
| // don't do it yet. |
| |
| double AdaptiveSizePolicy::decaying_gc_cost() const { |
| double decayed_major_gc_cost = major_gc_cost(); |
| double avg_major_interval = major_gc_interval_average_for_decay(); |
| if (UseAdaptiveSizeDecayMajorGCCost && |
| (AdaptiveSizeMajorGCDecayTimeScale > 0) && |
| (avg_major_interval > 0.00)) { |
| double time_since_last_major_gc = time_since_major_gc(); |
| |
| // Decay the major gc cost? |
| if (time_since_last_major_gc > |
| ((double) AdaptiveSizeMajorGCDecayTimeScale) * avg_major_interval) { |
| |
| // Decay using the time-since-last-major-gc |
| decayed_major_gc_cost = decaying_major_gc_cost(); |
| if (PrintGCDetails && Verbose) { |
| gclog_or_tty->print_cr("\ndecaying_gc_cost: major interval average:" |
| " %f time since last major gc: %f", |
| avg_major_interval, time_since_last_major_gc); |
| gclog_or_tty->print_cr(" major gc cost: %f decayed major gc cost: %f", |
| major_gc_cost(), decayed_major_gc_cost); |
| } |
| } |
| } |
| double result = MIN2(1.0, decayed_major_gc_cost + minor_gc_cost()); |
| return result; |
| } |
| |
| |
| void AdaptiveSizePolicy::clear_generation_free_space_flags() { |
| set_change_young_gen_for_min_pauses(0); |
| set_change_old_gen_for_maj_pauses(0); |
| |
| set_change_old_gen_for_throughput(0); |
| set_change_young_gen_for_throughput(0); |
| set_decrease_for_footprint(0); |
| set_decide_at_full_gc(0); |
| } |
| |
| void AdaptiveSizePolicy::check_gc_overhead_limit( |
| size_t young_live, |
| size_t eden_live, |
| size_t max_old_gen_size, |
| size_t max_eden_size, |
| bool is_full_gc, |
| GCCause::Cause gc_cause, |
| CollectorPolicy* collector_policy) { |
| |
| // Ignore explicit GC's. Exiting here does not set the flag and |
| // does not reset the count. Updating of the averages for system |
| // GC's is still controlled by UseAdaptiveSizePolicyWithSystemGC. |
| if (GCCause::is_user_requested_gc(gc_cause) || |
| GCCause::is_serviceability_requested_gc(gc_cause)) { |
| return; |
| } |
| // eden_limit is the upper limit on the size of eden based on |
| // the maximum size of the young generation and the sizes |
| // of the survivor space. |
| // The question being asked is whether the gc costs are high |
| // and the space being recovered by a collection is low. |
| // free_in_young_gen is the free space in the young generation |
| // after a collection and promo_live is the free space in the old |
| // generation after a collection. |
| // |
| // Use the minimum of the current value of the live in the |
| // young gen or the average of the live in the young gen. |
| // If the current value drops quickly, that should be taken |
| // into account (i.e., don't trigger if the amount of free |
| // space has suddenly jumped up). If the current is much |
| // higher than the average, use the average since it represents |
| // the longer term behavor. |
| const size_t live_in_eden = |
| MIN2(eden_live, (size_t) avg_eden_live()->average()); |
| const size_t free_in_eden = max_eden_size > live_in_eden ? |
| max_eden_size - live_in_eden : 0; |
| const size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average()); |
| const size_t total_free_limit = free_in_old_gen + free_in_eden; |
| const size_t total_mem = max_old_gen_size + max_eden_size; |
| const double mem_free_limit = total_mem * (GCHeapFreeLimit/100.0); |
| const double mem_free_old_limit = max_old_gen_size * (GCHeapFreeLimit/100.0); |
| const double mem_free_eden_limit = max_eden_size * (GCHeapFreeLimit/100.0); |
| const double gc_cost_limit = GCTimeLimit/100.0; |
| size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average()); |
| // But don't force a promo size below the current promo size. Otherwise, |
| // the promo size will shrink for no good reason. |
| promo_limit = MAX2(promo_limit, _promo_size); |
| |
| |
| if (PrintAdaptiveSizePolicy && (Verbose || |
| (free_in_old_gen < (size_t) mem_free_old_limit && |
| free_in_eden < (size_t) mem_free_eden_limit))) { |
| gclog_or_tty->print_cr( |
| "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; |
| if (is_full_gc) { |
| 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); |
| if (PrintGCDetails && Verbose) { |
| gclog_or_tty->print_cr(" 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 && PrintGCDetails && Verbose) { |
| if (gc_overhead_limit_exceeded()) { |
| gclog_or_tty->print_cr(" GC is exceeding overhead limit " |
| "of %d%%", (int) 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"); |
| gclog_or_tty->print_cr(" GC would exceed overhead limit " |
| "of %d%% %d consecutive time(s)", |
| (int) GCTimeLimit, gc_overhead_limit_count()); |
| } |
| } |
| } |
| // Printing |
| |
| bool AdaptiveSizePolicy::print_adaptive_size_policy_on(outputStream* st) const { |
| |
| // Should only be used with adaptive size policy turned on. |
| // Otherwise, there may be variables that are undefined. |
| if (!UseAdaptiveSizePolicy) 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; |
| } |
| |
| st->print_cr(" UseAdaptiveSizePolicy actions to meet %s", action); |
| st->print_cr(" GC overhead (%%)"); |
| st->print_cr(" Young generation: %7.2f\t %s", |
| 100.0 * avg_minor_gc_cost()->average(), |
| young_gen_action); |
| st->print_cr(" Tenured generation: %7.2f\t %s", |
| 100.0 * avg_major_gc_cost()->average(), |
| tenured_gen_action); |
| return true; |
| } |
| |
| bool AdaptiveSizePolicy::print_adaptive_size_policy_on( |
| outputStream* st, |
| uint tenuring_threshold_arg) const { |
| if (!AdaptiveSizePolicy::print_adaptive_size_policy_on(st)) { |
| return false; |
| } |
| |
| // Tenuring threshold |
| bool tenuring_threshold_changed = true; |
| if (decrement_tenuring_threshold_for_survivor_limit()) { |
| st->print(" Tenuring threshold: (attempted to decrease to avoid" |
| " survivor space overflow) = "); |
| } else if (decrement_tenuring_threshold_for_gc_cost()) { |
| st->print(" Tenuring threshold: (attempted to decrease to balance" |
| " GC costs) = "); |
| } else if (increment_tenuring_threshold_for_gc_cost()) { |
| st->print(" Tenuring threshold: (attempted to increase to balance" |
| " GC costs) = "); |
| } else { |
| tenuring_threshold_changed = false; |
| assert(!tenuring_threshold_change(), "(no change was attempted)"); |
| } |
| if (tenuring_threshold_changed) { |
| st->print_cr("%u", tenuring_threshold_arg); |
| } |
| return true; |
| } |
