diff -r 000000000000 -r a61af66fc99e src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,1334 @@ +/* + * Copyright 2004-2006 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/_cmsAdaptiveSizePolicy.cpp.incl" + +elapsedTimer CMSAdaptiveSizePolicy::_concurrent_timer; +elapsedTimer CMSAdaptiveSizePolicy::_STW_timer; + +// Defined if the granularity of the time measurements is potentially too large. +#define CLOCK_GRANULARITY_TOO_LARGE + +CMSAdaptiveSizePolicy::CMSAdaptiveSizePolicy(size_t init_eden_size, + size_t init_promo_size, + size_t init_survivor_size, + double max_gc_minor_pause_sec, + double max_gc_pause_sec, + uint gc_cost_ratio) : + AdaptiveSizePolicy(init_eden_size, + init_promo_size, + init_survivor_size, + max_gc_pause_sec, + gc_cost_ratio) { + + clear_internal_time_intervals(); + + _processor_count = os::active_processor_count(); + + if (CMSConcurrentMTEnabled && (ParallelCMSThreads > 1)) { + assert(_processor_count > 0, "Processor count is suspect"); + _concurrent_processor_count = MIN2((uint) ParallelCMSThreads, + (uint) _processor_count); + } else { + _concurrent_processor_count = 1; + } + + _avg_concurrent_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + _avg_concurrent_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + _avg_concurrent_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + + _avg_initial_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight, + PausePadding); + _avg_remark_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight, + PausePadding); + + _avg_cms_STW_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + _avg_cms_STW_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + + _avg_cms_free = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + _avg_cms_free_at_sweep = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + _avg_cms_promo = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + + // Mark-sweep-compact + _avg_msc_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + _avg_msc_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + _avg_msc_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + + // Mark-sweep + _avg_ms_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + _avg_ms_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + _avg_ms_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); + + // Variables that estimate pause times as a function of generation + // size. + _remark_pause_old_estimator = + new LinearLeastSquareFit(AdaptiveSizePolicyWeight); + _initial_pause_old_estimator = + new LinearLeastSquareFit(AdaptiveSizePolicyWeight); + _remark_pause_young_estimator = + new LinearLeastSquareFit(AdaptiveSizePolicyWeight); + _initial_pause_young_estimator = + new LinearLeastSquareFit(AdaptiveSizePolicyWeight); + + // Alignment comes from that used in ReservedSpace. + _generation_alignment = os::vm_allocation_granularity(); + + // Start the concurrent timer here so that the first + // concurrent_phases_begin() measures a finite mutator + // time. A finite mutator time is used to determine + // if a concurrent collection has been started. If this + // proves to be a problem, use some explicit flag to + // signal that a concurrent collection has been started. + _concurrent_timer.start(); + _STW_timer.start(); +} + +double CMSAdaptiveSizePolicy::concurrent_processor_fraction() { + // For now assume no other daemon threads are taking alway + // cpu's from the application. + return ((double) _concurrent_processor_count / (double) _processor_count); +} + +double CMSAdaptiveSizePolicy::concurrent_collection_cost( + double interval_in_seconds) { + // When the precleaning and sweeping phases use multiple + // threads, change one_processor_fraction to + // concurrent_processor_fraction(). + double one_processor_fraction = 1.0 / ((double) processor_count()); + double concurrent_cost = + collection_cost(_latest_cms_concurrent_marking_time_secs, + interval_in_seconds) * concurrent_processor_fraction() + + collection_cost(_latest_cms_concurrent_precleaning_time_secs, + interval_in_seconds) * one_processor_fraction + + collection_cost(_latest_cms_concurrent_sweeping_time_secs, + interval_in_seconds) * one_processor_fraction; + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr( + "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_cost(%f) " + "_latest_cms_concurrent_marking_cost %f " + "_latest_cms_concurrent_precleaning_cost %f " + "_latest_cms_concurrent_sweeping_cost %f " + "concurrent_processor_fraction %f " + "concurrent_cost %f ", + interval_in_seconds, + collection_cost(_latest_cms_concurrent_marking_time_secs, + interval_in_seconds), + collection_cost(_latest_cms_concurrent_precleaning_time_secs, + interval_in_seconds), + collection_cost(_latest_cms_concurrent_sweeping_time_secs, + interval_in_seconds), + concurrent_processor_fraction(), + concurrent_cost); + } + return concurrent_cost; +} + +double CMSAdaptiveSizePolicy::concurrent_collection_time() { + double latest_cms_sum_concurrent_phases_time_secs = + _latest_cms_concurrent_marking_time_secs + + _latest_cms_concurrent_precleaning_time_secs + + _latest_cms_concurrent_sweeping_time_secs; + return latest_cms_sum_concurrent_phases_time_secs; +} + +double CMSAdaptiveSizePolicy::scaled_concurrent_collection_time() { + // When the precleaning and sweeping phases use multiple + // threads, change one_processor_fraction to + // concurrent_processor_fraction(). + double one_processor_fraction = 1.0 / ((double) processor_count()); + double latest_cms_sum_concurrent_phases_time_secs = + _latest_cms_concurrent_marking_time_secs * concurrent_processor_fraction() + + _latest_cms_concurrent_precleaning_time_secs * one_processor_fraction + + _latest_cms_concurrent_sweeping_time_secs * one_processor_fraction ; + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr( + "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_time " + "_latest_cms_concurrent_marking_time_secs %f " + "_latest_cms_concurrent_precleaning_time_secs %f " + "_latest_cms_concurrent_sweeping_time_secs %f " + "concurrent_processor_fraction %f " + "latest_cms_sum_concurrent_phases_time_secs %f ", + _latest_cms_concurrent_marking_time_secs, + _latest_cms_concurrent_precleaning_time_secs, + _latest_cms_concurrent_sweeping_time_secs, + concurrent_processor_fraction(), + latest_cms_sum_concurrent_phases_time_secs); + } + return latest_cms_sum_concurrent_phases_time_secs; +} + +void CMSAdaptiveSizePolicy::update_minor_pause_old_estimator( + double minor_pause_in_ms) { + // Get the equivalent of the free space + // that is available for promotions in the CMS generation + // and use that to update _minor_pause_old_estimator + + // Don't implement this until it is needed. A warning is + // printed if _minor_pause_old_estimator is used. +} + +void CMSAdaptiveSizePolicy::concurrent_marking_begin() { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print(" "); + gclog_or_tty->stamp(); + gclog_or_tty->print(": concurrent_marking_begin "); + } + // Update the interval time + _concurrent_timer.stop(); + _latest_cms_collection_end_to_collection_start_secs = _concurrent_timer.seconds(); + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_begin: " + "mutator time %f", _latest_cms_collection_end_to_collection_start_secs); + } + _concurrent_timer.reset(); + _concurrent_timer.start(); +} + +void CMSAdaptiveSizePolicy::concurrent_marking_end() { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->stamp(); + gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_end()"); + } + + _concurrent_timer.stop(); + _latest_cms_concurrent_marking_time_secs = _concurrent_timer.seconds(); + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_marking_end" + ":concurrent marking time (s) %f", + _latest_cms_concurrent_marking_time_secs); + } +} + +void CMSAdaptiveSizePolicy::concurrent_precleaning_begin() { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->stamp(); + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::concurrent_precleaning_begin()"); + } + _concurrent_timer.reset(); + _concurrent_timer.start(); +} + + +void CMSAdaptiveSizePolicy::concurrent_precleaning_end() { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->stamp(); + gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_precleaning_end()"); + } + + _concurrent_timer.stop(); + // May be set again by a second call during the same collection. + _latest_cms_concurrent_precleaning_time_secs = _concurrent_timer.seconds(); + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_precleaning_end" + ":concurrent precleaning time (s) %f", + _latest_cms_concurrent_precleaning_time_secs); + } +} + +void CMSAdaptiveSizePolicy::concurrent_sweeping_begin() { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->stamp(); + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::concurrent_sweeping_begin()"); + } + _concurrent_timer.reset(); + _concurrent_timer.start(); +} + + +void CMSAdaptiveSizePolicy::concurrent_sweeping_end() { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->stamp(); + gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_sweeping_end()"); + } + + _concurrent_timer.stop(); + _latest_cms_concurrent_sweeping_time_secs = _concurrent_timer.seconds(); + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_sweeping_end" + ":concurrent sweeping time (s) %f", + _latest_cms_concurrent_sweeping_time_secs); + } +} + +void CMSAdaptiveSizePolicy::concurrent_phases_end(GCCause::Cause gc_cause, + size_t cur_eden, + size_t cur_promo) { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print(" "); + gclog_or_tty->stamp(); + gclog_or_tty->print(": concurrent_phases_end "); + } + + // Update the concurrent timer + _concurrent_timer.stop(); + + if (gc_cause != GCCause::_java_lang_system_gc || + UseAdaptiveSizePolicyWithSystemGC) { + + avg_cms_free()->sample(cur_promo); + double latest_cms_sum_concurrent_phases_time_secs = + concurrent_collection_time(); + + _avg_concurrent_time->sample(latest_cms_sum_concurrent_phases_time_secs); + + // Cost of collection (unit-less) + + // Total interval for collection. May not be valid. Tests + // below determine whether to use this. + // + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::concurrent_phases_end \n" + "_latest_cms_reset_end_to_initial_mark_start_secs %f \n" + "_latest_cms_initial_mark_start_to_end_time_secs %f \n" + "_latest_cms_remark_start_to_end_time_secs %f \n" + "_latest_cms_concurrent_marking_time_secs %f \n" + "_latest_cms_concurrent_precleaning_time_secs %f \n" + "_latest_cms_concurrent_sweeping_time_secs %f \n" + "latest_cms_sum_concurrent_phases_time_secs %f \n" + "_latest_cms_collection_end_to_collection_start_secs %f \n" + "concurrent_processor_fraction %f", + _latest_cms_reset_end_to_initial_mark_start_secs, + _latest_cms_initial_mark_start_to_end_time_secs, + _latest_cms_remark_start_to_end_time_secs, + _latest_cms_concurrent_marking_time_secs, + _latest_cms_concurrent_precleaning_time_secs, + _latest_cms_concurrent_sweeping_time_secs, + latest_cms_sum_concurrent_phases_time_secs, + _latest_cms_collection_end_to_collection_start_secs, + concurrent_processor_fraction()); + } + double interval_in_seconds = + _latest_cms_initial_mark_start_to_end_time_secs + + _latest_cms_remark_start_to_end_time_secs + + latest_cms_sum_concurrent_phases_time_secs + + _latest_cms_collection_end_to_collection_start_secs; + assert(interval_in_seconds >= 0.0, + "Bad interval between cms collections"); + + // Sample for performance counter + avg_concurrent_interval()->sample(interval_in_seconds); + + // STW costs (initial and remark pauses) + // Cost of collection (unit-less) + assert(_latest_cms_initial_mark_start_to_end_time_secs >= 0.0, + "Bad initial mark pause"); + assert(_latest_cms_remark_start_to_end_time_secs >= 0.0, + "Bad remark pause"); + double STW_time_in_seconds = + _latest_cms_initial_mark_start_to_end_time_secs + + _latest_cms_remark_start_to_end_time_secs; + double STW_collection_cost = 0.0; + if (interval_in_seconds > 0.0) { + // cost for the STW phases of the concurrent collection. + STW_collection_cost = STW_time_in_seconds / interval_in_seconds; + avg_cms_STW_gc_cost()->sample(STW_collection_cost); + } + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print("cmsAdaptiveSizePolicy::STW_collection_end: " + "STW gc cost: %f average: %f", STW_collection_cost, + avg_cms_STW_gc_cost()->average()); + gclog_or_tty->print_cr(" STW pause: %f (ms) STW period %f (ms)", + (double) STW_time_in_seconds * MILLIUNITS, + (double) interval_in_seconds * MILLIUNITS); + } + + double concurrent_cost = 0.0; + if (latest_cms_sum_concurrent_phases_time_secs > 0.0) { + concurrent_cost = concurrent_collection_cost(interval_in_seconds); + + avg_concurrent_gc_cost()->sample(concurrent_cost); + // Average this ms cost into all the other types gc costs + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print("cmsAdaptiveSizePolicy::concurrent_phases_end: " + "concurrent gc cost: %f average: %f", + concurrent_cost, + _avg_concurrent_gc_cost->average()); + gclog_or_tty->print_cr(" concurrent time: %f (ms) cms period %f (ms)" + " processor fraction: %f", + latest_cms_sum_concurrent_phases_time_secs * MILLIUNITS, + interval_in_seconds * MILLIUNITS, + concurrent_processor_fraction()); + } + } + double total_collection_cost = STW_collection_cost + concurrent_cost; + avg_major_gc_cost()->sample(total_collection_cost); + + // Gather information for estimating future behavior + double initial_pause_in_ms = _latest_cms_initial_mark_start_to_end_time_secs * MILLIUNITS; + double remark_pause_in_ms = _latest_cms_remark_start_to_end_time_secs * MILLIUNITS; + + double cur_promo_size_in_mbytes = ((double)cur_promo)/((double)M); + initial_pause_old_estimator()->update(cur_promo_size_in_mbytes, + initial_pause_in_ms); + remark_pause_old_estimator()->update(cur_promo_size_in_mbytes, + remark_pause_in_ms); + major_collection_estimator()->update(cur_promo_size_in_mbytes, + total_collection_cost); + + // This estimate uses the average eden size. It could also + // have used the latest eden size. Which is better? + double cur_eden_size_in_mbytes = ((double)cur_eden)/((double) M); + initial_pause_young_estimator()->update(cur_eden_size_in_mbytes, + initial_pause_in_ms); + remark_pause_young_estimator()->update(cur_eden_size_in_mbytes, + remark_pause_in_ms); + } + + clear_internal_time_intervals(); + + set_first_after_collection(); + + // The concurrent phases keeps track of it's own mutator interval + // with this timer. This allows the stop-the-world phase to + // be included in the mutator time so that the stop-the-world time + // is not double counted. Reset and start it. + _concurrent_timer.reset(); + _concurrent_timer.start(); + + // The mutator time between STW phases does not include the + // concurrent collection time. + _STW_timer.reset(); + _STW_timer.start(); +} + +void CMSAdaptiveSizePolicy::checkpoint_roots_initial_begin() { + // Update the interval time + _STW_timer.stop(); + _latest_cms_reset_end_to_initial_mark_start_secs = _STW_timer.seconds(); + // Reset for the initial mark + _STW_timer.reset(); + _STW_timer.start(); +} + +void CMSAdaptiveSizePolicy::checkpoint_roots_initial_end( + GCCause::Cause gc_cause) { + _STW_timer.stop(); + + if (gc_cause != GCCause::_java_lang_system_gc || + UseAdaptiveSizePolicyWithSystemGC) { + _latest_cms_initial_mark_start_to_end_time_secs = _STW_timer.seconds(); + avg_initial_pause()->sample(_latest_cms_initial_mark_start_to_end_time_secs); + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print( + "cmsAdaptiveSizePolicy::checkpoint_roots_initial_end: " + "initial pause: %f ", _latest_cms_initial_mark_start_to_end_time_secs); + } + } + + _STW_timer.reset(); + _STW_timer.start(); +} + +void CMSAdaptiveSizePolicy::checkpoint_roots_final_begin() { + _STW_timer.stop(); + _latest_cms_initial_mark_end_to_remark_start_secs = _STW_timer.seconds(); + // Start accumumlating time for the remark in the STW timer. + _STW_timer.reset(); + _STW_timer.start(); +} + +void CMSAdaptiveSizePolicy::checkpoint_roots_final_end( + GCCause::Cause gc_cause) { + _STW_timer.stop(); + if (gc_cause != GCCause::_java_lang_system_gc || + UseAdaptiveSizePolicyWithSystemGC) { + // Total initial mark pause + remark pause. + _latest_cms_remark_start_to_end_time_secs = _STW_timer.seconds(); + double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + + _latest_cms_remark_start_to_end_time_secs; + double STW_time_in_ms = STW_time_in_seconds * MILLIUNITS; + + avg_remark_pause()->sample(_latest_cms_remark_start_to_end_time_secs); + + // Sample total for initial mark + remark + avg_cms_STW_time()->sample(STW_time_in_seconds); + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print("cmsAdaptiveSizePolicy::checkpoint_roots_final_end: " + "remark pause: %f", _latest_cms_remark_start_to_end_time_secs); + } + + } + // Don't start the STW times here because the concurrent + // sweep and reset has not happened. + // Keep the old comment above in case I don't understand + // what is going on but now + // Start the STW timer because it is used by ms_collection_begin() + // and ms_collection_end() to get the sweep time if a MS is being + // done in the foreground. + _STW_timer.reset(); + _STW_timer.start(); +} + +void CMSAdaptiveSizePolicy::msc_collection_begin() { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print(" "); + gclog_or_tty->stamp(); + gclog_or_tty->print(": msc_collection_begin "); + } + _STW_timer.stop(); + _latest_cms_msc_end_to_msc_start_time_secs = _STW_timer.seconds(); + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::msc_collection_begin: " + "mutator time %f", + _latest_cms_msc_end_to_msc_start_time_secs); + } + avg_msc_interval()->sample(_latest_cms_msc_end_to_msc_start_time_secs); + _STW_timer.reset(); + _STW_timer.start(); +} + +void CMSAdaptiveSizePolicy::msc_collection_end(GCCause::Cause gc_cause) { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print(" "); + gclog_or_tty->stamp(); + gclog_or_tty->print(": msc_collection_end "); + } + _STW_timer.stop(); + if (gc_cause != GCCause::_java_lang_system_gc || + UseAdaptiveSizePolicyWithSystemGC) { + double msc_pause_in_seconds = _STW_timer.seconds(); + if ((_latest_cms_msc_end_to_msc_start_time_secs > 0.0) && + (msc_pause_in_seconds > 0.0)) { + avg_msc_pause()->sample(msc_pause_in_seconds); + double mutator_time_in_seconds = 0.0; + if (_latest_cms_collection_end_to_collection_start_secs == 0.0) { + // This assertion may fail because of time stamp gradularity. + // Comment it out and investiage it at a later time. The large + // time stamp granularity occurs on some older linux systems. +#ifndef CLOCK_GRANULARITY_TOO_LARGE + assert((_latest_cms_concurrent_marking_time_secs == 0.0) && + (_latest_cms_concurrent_precleaning_time_secs == 0.0) && + (_latest_cms_concurrent_sweeping_time_secs == 0.0), + "There should not be any concurrent time"); +#endif + // A concurrent collection did not start. Mutator time + // between collections comes from the STW MSC timer. + mutator_time_in_seconds = _latest_cms_msc_end_to_msc_start_time_secs; + } else { + // The concurrent collection did start so count the mutator + // time to the start of the concurrent collection. In this + // case the _latest_cms_msc_end_to_msc_start_time_secs measures + // the time between the initial mark or remark and the + // start of the MSC. That has no real meaning. + mutator_time_in_seconds = _latest_cms_collection_end_to_collection_start_secs; + } + + double latest_cms_sum_concurrent_phases_time_secs = + concurrent_collection_time(); + double interval_in_seconds = + mutator_time_in_seconds + + _latest_cms_initial_mark_start_to_end_time_secs + + _latest_cms_remark_start_to_end_time_secs + + latest_cms_sum_concurrent_phases_time_secs + + msc_pause_in_seconds; + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr(" interval_in_seconds %f \n" + " mutator_time_in_seconds %f \n" + " _latest_cms_initial_mark_start_to_end_time_secs %f\n" + " _latest_cms_remark_start_to_end_time_secs %f\n" + " latest_cms_sum_concurrent_phases_time_secs %f\n" + " msc_pause_in_seconds %f\n", + interval_in_seconds, + mutator_time_in_seconds, + _latest_cms_initial_mark_start_to_end_time_secs, + _latest_cms_remark_start_to_end_time_secs, + latest_cms_sum_concurrent_phases_time_secs, + msc_pause_in_seconds); + } + + // The concurrent cost is wasted cost but it should be + // included. + double concurrent_cost = concurrent_collection_cost(interval_in_seconds); + + // Initial mark and remark, also wasted. + double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + + _latest_cms_remark_start_to_end_time_secs; + double STW_collection_cost = + collection_cost(STW_time_in_seconds, interval_in_seconds) + + concurrent_cost; + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr(" msc_collection_end:\n" + "_latest_cms_collection_end_to_collection_start_secs %f\n" + "_latest_cms_msc_end_to_msc_start_time_secs %f\n" + "_latest_cms_initial_mark_start_to_end_time_secs %f\n" + "_latest_cms_remark_start_to_end_time_secs %f\n" + "latest_cms_sum_concurrent_phases_time_secs %f\n", + _latest_cms_collection_end_to_collection_start_secs, + _latest_cms_msc_end_to_msc_start_time_secs, + _latest_cms_initial_mark_start_to_end_time_secs, + _latest_cms_remark_start_to_end_time_secs, + latest_cms_sum_concurrent_phases_time_secs); + + gclog_or_tty->print_cr(" msc_collection_end: \n" + "latest_cms_sum_concurrent_phases_time_secs %f\n" + "STW_time_in_seconds %f\n" + "msc_pause_in_seconds %f\n", + latest_cms_sum_concurrent_phases_time_secs, + STW_time_in_seconds, + msc_pause_in_seconds); + } + + double cost = concurrent_cost + STW_collection_cost + + collection_cost(msc_pause_in_seconds, interval_in_seconds); + + _avg_msc_gc_cost->sample(cost); + + // Average this ms cost into all the other types gc costs + avg_major_gc_cost()->sample(cost); + + // Sample for performance counter + _avg_msc_interval->sample(interval_in_seconds); + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print("cmsAdaptiveSizePolicy::msc_collection_end: " + "MSC gc cost: %f average: %f", cost, + _avg_msc_gc_cost->average()); + + double msc_pause_in_ms = msc_pause_in_seconds * MILLIUNITS; + gclog_or_tty->print_cr(" MSC pause: %f (ms) MSC period %f (ms)", + msc_pause_in_ms, (double) interval_in_seconds * MILLIUNITS); + } + } + } + + clear_internal_time_intervals(); + + // Can this call be put into the epilogue? + set_first_after_collection(); + + // The concurrent phases keeps track of it's own mutator interval + // with this timer. This allows the stop-the-world phase to + // be included in the mutator time so that the stop-the-world time + // is not double counted. Reset and start it. + _concurrent_timer.stop(); + _concurrent_timer.reset(); + _concurrent_timer.start(); + + _STW_timer.reset(); + _STW_timer.start(); +} + +void CMSAdaptiveSizePolicy::ms_collection_begin() { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print(" "); + gclog_or_tty->stamp(); + gclog_or_tty->print(": ms_collection_begin "); + } + _STW_timer.stop(); + _latest_cms_ms_end_to_ms_start = _STW_timer.seconds(); + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::ms_collection_begin: " + "mutator time %f", + _latest_cms_ms_end_to_ms_start); + } + avg_ms_interval()->sample(_STW_timer.seconds()); + _STW_timer.reset(); + _STW_timer.start(); +} + +void CMSAdaptiveSizePolicy::ms_collection_end(GCCause::Cause gc_cause) { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print(" "); + gclog_or_tty->stamp(); + gclog_or_tty->print(": ms_collection_end "); + } + _STW_timer.stop(); + if (gc_cause != GCCause::_java_lang_system_gc || + UseAdaptiveSizePolicyWithSystemGC) { + // The MS collection is a foreground collection that does all + // the parts of a mostly concurrent collection. + // + // For this collection include the cost of the + // initial mark + // remark + // all concurrent time (scaled down by the + // concurrent_processor_fraction). Some + // may be zero if the baton was passed before + // it was reached. + // concurrent marking + // sweeping + // resetting + // STW after baton was passed (STW_in_foreground_in_seconds) + double STW_in_foreground_in_seconds = _STW_timer.seconds(); + + double latest_cms_sum_concurrent_phases_time_secs = + concurrent_collection_time(); + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::ms_collecton_end " + "STW_in_foreground_in_seconds %f " + "_latest_cms_initial_mark_start_to_end_time_secs %f " + "_latest_cms_remark_start_to_end_time_secs %f " + "latest_cms_sum_concurrent_phases_time_secs %f " + "_latest_cms_ms_marking_start_to_end_time_secs %f " + "_latest_cms_ms_end_to_ms_start %f", + STW_in_foreground_in_seconds, + _latest_cms_initial_mark_start_to_end_time_secs, + _latest_cms_remark_start_to_end_time_secs, + latest_cms_sum_concurrent_phases_time_secs, + _latest_cms_ms_marking_start_to_end_time_secs, + _latest_cms_ms_end_to_ms_start); + } + + double STW_marking_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + + _latest_cms_remark_start_to_end_time_secs; +#ifndef CLOCK_GRANULARITY_TOO_LARGE + assert(_latest_cms_ms_marking_start_to_end_time_secs == 0.0 || + latest_cms_sum_concurrent_phases_time_secs == 0.0, + "marking done twice?"); +#endif + double ms_time_in_seconds = STW_marking_in_seconds + + STW_in_foreground_in_seconds + + _latest_cms_ms_marking_start_to_end_time_secs + + scaled_concurrent_collection_time(); + avg_ms_pause()->sample(ms_time_in_seconds); + // Use the STW costs from the initial mark and remark plus + // the cost of the concurrent phase to calculate a + // collection cost. + double cost = 0.0; + if ((_latest_cms_ms_end_to_ms_start > 0.0) && + (ms_time_in_seconds > 0.0)) { + double interval_in_seconds = + _latest_cms_ms_end_to_ms_start + ms_time_in_seconds; + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("\n ms_time_in_seconds %f " + "latest_cms_sum_concurrent_phases_time_secs %f " + "interval_in_seconds %f", + ms_time_in_seconds, + latest_cms_sum_concurrent_phases_time_secs, + interval_in_seconds); + } + + cost = collection_cost(ms_time_in_seconds, interval_in_seconds); + + _avg_ms_gc_cost->sample(cost); + // Average this ms cost into all the other types gc costs + avg_major_gc_cost()->sample(cost); + + // Sample for performance counter + _avg_ms_interval->sample(interval_in_seconds); + } + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print("cmsAdaptiveSizePolicy::ms_collection_end: " + "MS gc cost: %f average: %f", cost, _avg_ms_gc_cost->average()); + + double ms_time_in_ms = ms_time_in_seconds * MILLIUNITS; + gclog_or_tty->print_cr(" MS pause: %f (ms) MS period %f (ms)", + ms_time_in_ms, + _latest_cms_ms_end_to_ms_start * MILLIUNITS); + } + } + + // Consider putting this code (here to end) into a + // method for convenience. + clear_internal_time_intervals(); + + set_first_after_collection(); + + // The concurrent phases keeps track of it's own mutator interval + // with this timer. This allows the stop-the-world phase to + // be included in the mutator time so that the stop-the-world time + // is not double counted. Reset and start it. + _concurrent_timer.stop(); + _concurrent_timer.reset(); + _concurrent_timer.start(); + + _STW_timer.reset(); + _STW_timer.start(); +} + +void CMSAdaptiveSizePolicy::clear_internal_time_intervals() { + _latest_cms_reset_end_to_initial_mark_start_secs = 0.0; + _latest_cms_initial_mark_end_to_remark_start_secs = 0.0; + _latest_cms_collection_end_to_collection_start_secs = 0.0; + _latest_cms_concurrent_marking_time_secs = 0.0; + _latest_cms_concurrent_precleaning_time_secs = 0.0; + _latest_cms_concurrent_sweeping_time_secs = 0.0; + _latest_cms_msc_end_to_msc_start_time_secs = 0.0; + _latest_cms_ms_end_to_ms_start = 0.0; + _latest_cms_remark_start_to_end_time_secs = 0.0; + _latest_cms_initial_mark_start_to_end_time_secs = 0.0; + _latest_cms_ms_marking_start_to_end_time_secs = 0.0; +} + +void CMSAdaptiveSizePolicy::clear_generation_free_space_flags() { + AdaptiveSizePolicy::clear_generation_free_space_flags(); + + set_change_young_gen_for_maj_pauses(0); +} + +void CMSAdaptiveSizePolicy::concurrent_phases_resume() { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->stamp(); + gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_phases_resume()"); + } + _concurrent_timer.start(); +} + +double CMSAdaptiveSizePolicy::time_since_major_gc() const { + _concurrent_timer.stop(); + double time_since_cms_gc = _concurrent_timer.seconds(); + _concurrent_timer.start(); + _STW_timer.stop(); + double time_since_STW_gc = _STW_timer.seconds(); + _STW_timer.start(); + + return MIN2(time_since_cms_gc, time_since_STW_gc); +} + +double CMSAdaptiveSizePolicy::major_gc_interval_average_for_decay() const { + double cms_interval = _avg_concurrent_interval->average(); + double msc_interval = _avg_msc_interval->average(); + double ms_interval = _avg_ms_interval->average(); + + return MAX3(cms_interval, msc_interval, ms_interval); +} + +double CMSAdaptiveSizePolicy::cms_gc_cost() const { + return avg_major_gc_cost()->average(); +} + +void CMSAdaptiveSizePolicy::ms_collection_marking_begin() { + _STW_timer.stop(); + // Start accumumlating time for the marking in the STW timer. + _STW_timer.reset(); + _STW_timer.start(); +} + +void CMSAdaptiveSizePolicy::ms_collection_marking_end( + GCCause::Cause gc_cause) { + _STW_timer.stop(); + if (gc_cause != GCCause::_java_lang_system_gc || + UseAdaptiveSizePolicyWithSystemGC) { + _latest_cms_ms_marking_start_to_end_time_secs = _STW_timer.seconds(); + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::" + "msc_collection_marking_end: mutator time %f", + _latest_cms_ms_marking_start_to_end_time_secs); + } + } + _STW_timer.reset(); + _STW_timer.start(); +} + +double CMSAdaptiveSizePolicy::gc_cost() const { + double cms_gen_cost = cms_gc_cost(); + double result = MIN2(1.0, minor_gc_cost() + cms_gen_cost); + assert(result >= 0.0, "Both minor and major costs are non-negative"); + return result; +} + +// Cost of collection (unit-less) +double CMSAdaptiveSizePolicy::collection_cost(double pause_in_seconds, + double interval_in_seconds) { + // Cost of collection (unit-less) + double cost = 0.0; + if ((interval_in_seconds > 0.0) && + (pause_in_seconds > 0.0)) { + cost = + pause_in_seconds / interval_in_seconds; + } + return cost; +} + +size_t CMSAdaptiveSizePolicy::adjust_eden_for_pause_time(size_t cur_eden) { + size_t change = 0; + size_t desired_eden = cur_eden; + + // reduce eden size + change = eden_decrement_aligned_down(cur_eden); + desired_eden = cur_eden - change; + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::adjust_eden_for_pause_time " + "adjusting eden for pause time. " + " starting eden size " SIZE_FORMAT + " reduced eden size " SIZE_FORMAT + " eden delta " SIZE_FORMAT, + cur_eden, desired_eden, change); + } + + return desired_eden; +} + +size_t CMSAdaptiveSizePolicy::adjust_eden_for_throughput(size_t cur_eden) { + + size_t desired_eden = cur_eden; + + set_change_young_gen_for_throughput(increase_young_gen_for_througput_true); + + size_t change = eden_increment_aligned_up(cur_eden); + size_t scaled_change = scale_by_gen_gc_cost(change, minor_gc_cost()); + + if (cur_eden + scaled_change > cur_eden) { + desired_eden = cur_eden + scaled_change; + } + + _young_gen_change_for_minor_throughput++; + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::adjust_eden_for_throughput " + "adjusting eden for throughput. " + " starting eden size " SIZE_FORMAT + " increased eden size " SIZE_FORMAT + " eden delta " SIZE_FORMAT, + cur_eden, desired_eden, scaled_change); + } + + return desired_eden; +} + +size_t CMSAdaptiveSizePolicy::adjust_eden_for_footprint(size_t cur_eden) { + + set_decrease_for_footprint(decrease_young_gen_for_footprint_true); + + size_t change = eden_decrement(cur_eden); + size_t desired_eden_size = cur_eden - change; + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::adjust_eden_for_footprint " + "adjusting eden for footprint. " + " starting eden size " SIZE_FORMAT + " reduced eden size " SIZE_FORMAT + " eden delta " SIZE_FORMAT, + cur_eden, desired_eden_size, change); + } + return desired_eden_size; +} + +// The eden and promo versions should be combined if possible. +// They are the same except that the sizes of the decrement +// and increment are different for eden and promo. +size_t CMSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) { + size_t delta = eden_decrement(cur_eden); + return align_size_down(delta, generation_alignment()); +} + +size_t CMSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) { + size_t delta = eden_increment(cur_eden); + return align_size_up(delta, generation_alignment()); +} + +size_t CMSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) { + size_t delta = promo_decrement(cur_promo); + return align_size_down(delta, generation_alignment()); +} + +size_t CMSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) { + size_t delta = promo_increment(cur_promo); + return align_size_up(delta, generation_alignment()); +} + + +void CMSAdaptiveSizePolicy::compute_young_generation_free_space(size_t cur_eden, + size_t max_eden_size) +{ + size_t desired_eden_size = cur_eden; + size_t eden_limit = max_eden_size; + + // Printout input + if (PrintGC && PrintAdaptiveSizePolicy) { + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::compute_young_generation_free_space: " + "cur_eden " SIZE_FORMAT, + cur_eden); + } + + // Used for diagnostics + clear_generation_free_space_flags(); + + if (_avg_minor_pause->padded_average() > gc_pause_goal_sec()) { + if (minor_pause_young_estimator()->decrement_will_decrease()) { + // If the minor pause is too long, shrink the young gen. + set_change_young_gen_for_min_pauses( + decrease_young_gen_for_min_pauses_true); + desired_eden_size = adjust_eden_for_pause_time(desired_eden_size); + } + } else if ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) || + (avg_initial_pause()->padded_average() > gc_pause_goal_sec())) { + // The remark or initial pauses are not meeting the goal. Should + // the generation be shrunk? + if (get_and_clear_first_after_collection() && + ((avg_remark_pause()->padded_average() > gc_pause_goal_sec() && + remark_pause_young_estimator()->decrement_will_decrease()) || + (avg_initial_pause()->padded_average() > gc_pause_goal_sec() && + initial_pause_young_estimator()->decrement_will_decrease()))) { + + set_change_young_gen_for_maj_pauses( + decrease_young_gen_for_maj_pauses_true); + + // If the remark or initial pause is too long and this is the + // first young gen collection after a cms collection, shrink + // the young gen. + desired_eden_size = adjust_eden_for_pause_time(desired_eden_size); + } + // If not the first young gen collection after a cms collection, + // don't do anything. In this case an adjustment has already + // been made and the results of the adjustment has not yet been + // measured. + } else if ((minor_gc_cost() >= 0.0) && + (adjusted_mutator_cost() < _throughput_goal)) { + desired_eden_size = adjust_eden_for_throughput(desired_eden_size); + } else { + desired_eden_size = adjust_eden_for_footprint(desired_eden_size); + } + + if (PrintGC && PrintAdaptiveSizePolicy) { + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::compute_young_generation_free_space limits:" + " desired_eden_size: " SIZE_FORMAT + " old_eden_size: " SIZE_FORMAT, + desired_eden_size, cur_eden); + } + + set_eden_size(desired_eden_size); +} + +size_t CMSAdaptiveSizePolicy::adjust_promo_for_pause_time(size_t cur_promo) { + size_t change = 0; + size_t desired_promo = cur_promo; + // Move this test up to caller like the adjust_eden_for_pause_time() + // call. + if ((AdaptiveSizePausePolicy == 0) && + ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) || + (avg_initial_pause()->padded_average() > gc_pause_goal_sec()))) { + set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true); + change = promo_decrement_aligned_down(cur_promo); + desired_promo = cur_promo - change; + } else if ((AdaptiveSizePausePolicy > 0) && + (((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) && + remark_pause_old_estimator()->decrement_will_decrease()) || + ((avg_initial_pause()->padded_average() > gc_pause_goal_sec()) && + initial_pause_old_estimator()->decrement_will_decrease()))) { + set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true); + change = promo_decrement_aligned_down(cur_promo); + desired_promo = cur_promo - change; + } + + if ((change != 0) &&PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::adjust_promo_for_pause_time " + "adjusting promo for pause time. " + " starting promo size " SIZE_FORMAT + " reduced promo size " SIZE_FORMAT + " promo delta " SIZE_FORMAT, + cur_promo, desired_promo, change); + } + + return desired_promo; +} + +// Try to share this with PS. +size_t CMSAdaptiveSizePolicy::scale_by_gen_gc_cost(size_t base_change, + double gen_gc_cost) { + + // Calculate the change to use for the tenured gen. + size_t scaled_change = 0; + // Can the increment to the generation be scaled? + if (gc_cost() >= 0.0 && gen_gc_cost >= 0.0) { + double scale_by_ratio = gen_gc_cost / gc_cost(); + scaled_change = + (size_t) (scale_by_ratio * (double) base_change); + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr( + "Scaled tenured increment: " SIZE_FORMAT " by %f down to " + SIZE_FORMAT, + base_change, scale_by_ratio, scaled_change); + } + } else if (gen_gc_cost >= 0.0) { + // Scaling is not going to work. If the major gc time is the + // larger than the other GC costs, give it a full increment. + if (gen_gc_cost >= (gc_cost() - gen_gc_cost)) { + scaled_change = base_change; + } + } else { + // Don't expect to get here but it's ok if it does + // in the product build since the delta will be 0 + // and nothing will change. + assert(false, "Unexpected value for gc costs"); + } + + return scaled_change; +} + +size_t CMSAdaptiveSizePolicy::adjust_promo_for_throughput(size_t cur_promo) { + + size_t desired_promo = cur_promo; + + set_change_old_gen_for_throughput(increase_old_gen_for_throughput_true); + + size_t change = promo_increment_aligned_up(cur_promo); + size_t scaled_change = scale_by_gen_gc_cost(change, major_gc_cost()); + + if (cur_promo + scaled_change > cur_promo) { + desired_promo = cur_promo + scaled_change; + } + + _old_gen_change_for_major_throughput++; + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::adjust_promo_for_throughput " + "adjusting promo for throughput. " + " starting promo size " SIZE_FORMAT + " increased promo size " SIZE_FORMAT + " promo delta " SIZE_FORMAT, + cur_promo, desired_promo, scaled_change); + } + + return desired_promo; +} + +size_t CMSAdaptiveSizePolicy::adjust_promo_for_footprint(size_t cur_promo, + size_t cur_eden) { + + set_decrease_for_footprint(decrease_young_gen_for_footprint_true); + + size_t change = promo_decrement(cur_promo); + size_t desired_promo_size = cur_promo - change; + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::adjust_promo_for_footprint " + "adjusting promo for footprint. " + " starting promo size " SIZE_FORMAT + " reduced promo size " SIZE_FORMAT + " promo delta " SIZE_FORMAT, + cur_promo, desired_promo_size, change); + } + return desired_promo_size; +} + +void CMSAdaptiveSizePolicy::compute_tenured_generation_free_space( + size_t cur_tenured_free, + size_t max_tenured_available, + size_t cur_eden) { + // This can be bad if the desired value grows/shrinks without + // any connection to the read free space + size_t desired_promo_size = promo_size(); + size_t tenured_limit = max_tenured_available; + + // Printout input + if (PrintGC && PrintAdaptiveSizePolicy) { + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space: " + "cur_tenured_free " SIZE_FORMAT + " max_tenured_available " SIZE_FORMAT, + cur_tenured_free, max_tenured_available); + } + + // Used for diagnostics + clear_generation_free_space_flags(); + + set_decide_at_full_gc(decide_at_full_gc_true); + if (avg_remark_pause()->padded_average() > gc_pause_goal_sec() || + avg_initial_pause()->padded_average() > gc_pause_goal_sec()) { + desired_promo_size = adjust_promo_for_pause_time(cur_tenured_free); + } else if (avg_minor_pause()->padded_average() > gc_pause_goal_sec()) { + // Nothing to do since the minor collections are too large and + // this method only deals with the cms generation. + } else if ((cms_gc_cost() >= 0.0) && + (adjusted_mutator_cost() < _throughput_goal)) { + desired_promo_size = adjust_promo_for_throughput(cur_tenured_free); + } else { + desired_promo_size = adjust_promo_for_footprint(cur_tenured_free, + cur_eden); + } + + if (PrintGC && PrintAdaptiveSizePolicy) { + gclog_or_tty->print_cr( + "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space limits:" + " desired_promo_size: " SIZE_FORMAT + " old_promo_size: " SIZE_FORMAT, + desired_promo_size, cur_tenured_free); + } + + set_promo_size(desired_promo_size); +} + +int CMSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold( + bool is_survivor_overflow, + int tenuring_threshold, + size_t survivor_limit) { + assert(survivor_limit >= generation_alignment(), + "survivor_limit too small"); + assert((size_t)align_size_down(survivor_limit, generation_alignment()) + == survivor_limit, "survivor_limit not aligned"); + + // Change UsePSAdaptiveSurvivorSizePolicy -> UseAdaptiveSurvivorSizePolicy? + if (!UsePSAdaptiveSurvivorSizePolicy || + !young_gen_policy_is_ready()) { + return tenuring_threshold; + } + + // We'll decide whether to increase or decrease the tenuring + // threshold based partly on the newly computed survivor size + // (if we hit the maximum limit allowed, we'll always choose to + // decrement the threshold). + bool incr_tenuring_threshold = false; + bool decr_tenuring_threshold = false; + + set_decrement_tenuring_threshold_for_gc_cost(false); + set_increment_tenuring_threshold_for_gc_cost(false); + set_decrement_tenuring_threshold_for_survivor_limit(false); + + if (!is_survivor_overflow) { + // Keep running averages on how much survived + + // We use the tenuring threshold to equalize the cost of major + // and minor collections. + // ThresholdTolerance is used to indicate how sensitive the + // tenuring threshold is to differences in cost betweent the + // collection types. + + // Get the times of interest. This involves a little work, so + // we cache the values here. + const double major_cost = major_gc_cost(); + const double minor_cost = minor_gc_cost(); + + if (minor_cost > major_cost * _threshold_tolerance_percent) { + // Minor times are getting too long; lower the threshold so + // less survives and more is promoted. + decr_tenuring_threshold = true; + set_decrement_tenuring_threshold_for_gc_cost(true); + } else if (major_cost > minor_cost * _threshold_tolerance_percent) { + // Major times are too long, so we want less promotion. + incr_tenuring_threshold = true; + set_increment_tenuring_threshold_for_gc_cost(true); + } + + } else { + // Survivor space overflow occurred, so promoted and survived are + // not accurate. We'll make our best guess by combining survived + // and promoted and count them as survivors. + // + // We'll lower the tenuring threshold to see if we can correct + // things. Also, set the survivor size conservatively. We're + // trying to avoid many overflows from occurring if defnew size + // is just too small. + + decr_tenuring_threshold = true; + } + + // The padded average also maintains a deviation from the average; + // we use this to see how good of an estimate we have of what survived. + // We're trying to pad the survivor size as little as possible without + // overflowing the survivor spaces. + size_t target_size = align_size_up((size_t)_avg_survived->padded_average(), + generation_alignment()); + target_size = MAX2(target_size, generation_alignment()); + + if (target_size > survivor_limit) { + // Target size is bigger than we can handle. Let's also reduce + // the tenuring threshold. + target_size = survivor_limit; + decr_tenuring_threshold = true; + set_decrement_tenuring_threshold_for_survivor_limit(true); + } + + // Finally, increment or decrement the tenuring threshold, as decided above. + // We test for decrementing first, as we might have hit the target size + // limit. + if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { + if (tenuring_threshold > 1) { + tenuring_threshold--; + } + } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { + if (tenuring_threshold < MaxTenuringThreshold) { + tenuring_threshold++; + } + } + + // We keep a running average of the amount promoted which is used + // to decide when we should collect the old generation (when + // the amount of old gen free space is less than what we expect to + // promote). + + if (PrintAdaptiveSizePolicy) { + // A little more detail if Verbose is on + GenCollectedHeap* gch = GenCollectedHeap::heap(); + if (Verbose) { + gclog_or_tty->print( " avg_survived: %f" + " avg_deviation: %f", + _avg_survived->average(), + _avg_survived->deviation()); + } + + gclog_or_tty->print( " avg_survived_padded_avg: %f", + _avg_survived->padded_average()); + + if (Verbose) { + gclog_or_tty->print( " avg_promoted_avg: %f" + " avg_promoted_dev: %f", + gch->gc_stats(1)->avg_promoted()->average(), + gch->gc_stats(1)->avg_promoted()->deviation()); + } + + gclog_or_tty->print( " avg_promoted_padded_avg: %f" + " avg_pretenured_padded_avg: %f" + " tenuring_thresh: %d" + " target_size: " SIZE_FORMAT + " survivor_limit: " SIZE_FORMAT, + gch->gc_stats(1)->avg_promoted()->padded_average(), + _avg_pretenured->padded_average(), + tenuring_threshold, target_size, survivor_limit); + gclog_or_tty->cr(); + } + + set_survivor_size(target_size); + + return tenuring_threshold; +} + +bool CMSAdaptiveSizePolicy::get_and_clear_first_after_collection() { + bool result = _first_after_collection; + _first_after_collection = false; + return result; +} + +bool CMSAdaptiveSizePolicy::print_adaptive_size_policy_on( + outputStream* st) const { + + if (!UseAdaptiveSizePolicy) return false; + + GenCollectedHeap* gch = GenCollectedHeap::heap(); + Generation* gen0 = gch->get_gen(0); + DefNewGeneration* def_new = gen0->as_DefNewGeneration(); + return + AdaptiveSizePolicy::print_adaptive_size_policy_on( + st, + def_new->tenuring_threshold()); +}