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view src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp @ 17546:46fa2940e686 jdk8u5-b07
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author | asaha |
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date | Sun, 02 Feb 2014 22:45:03 -0800 |
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/* * Copyright (c) 2004, 2013, 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. * */ #ifndef SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_CMSADAPTIVESIZEPOLICY_HPP #define SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_CMSADAPTIVESIZEPOLICY_HPP #include "gc_implementation/shared/adaptiveSizePolicy.hpp" #include "runtime/timer.hpp" // This class keeps statistical information and computes the // size of the heap for the concurrent mark sweep collector. // // Cost for garbage collector include cost for // minor collection // concurrent collection // stop-the-world component // concurrent component // major compacting collection // uses decaying cost // Forward decls class elapsedTimer; class CMSAdaptiveSizePolicy : public AdaptiveSizePolicy { friend class CMSGCAdaptivePolicyCounters; friend class CMSCollector; private: // Total number of processors available int _processor_count; // Number of processors used by the concurrent phases of GC // This number is assumed to be the same for all concurrent // phases. int _concurrent_processor_count; // Time that the mutators run exclusive of a particular // phase. For example, the time the mutators run excluding // the time during which the cms collector runs concurrently // with the mutators. // Between end of most recent cms reset and start of initial mark // This may be redundant double _latest_cms_reset_end_to_initial_mark_start_secs; // Between end of the most recent initial mark and start of remark double _latest_cms_initial_mark_end_to_remark_start_secs; // Between end of most recent collection and start of // a concurrent collection double _latest_cms_collection_end_to_collection_start_secs; // Times of the concurrent phases of the most recent // concurrent collection double _latest_cms_concurrent_marking_time_secs; double _latest_cms_concurrent_precleaning_time_secs; double _latest_cms_concurrent_sweeping_time_secs; // Between end of most recent STW MSC and start of next STW MSC double _latest_cms_msc_end_to_msc_start_time_secs; // Between end of most recent MS and start of next MS // This does not include any time spent during a concurrent // collection. double _latest_cms_ms_end_to_ms_start; // Between start and end of the initial mark of the most recent // concurrent collection. double _latest_cms_initial_mark_start_to_end_time_secs; // Between start and end of the remark phase of the most recent // concurrent collection double _latest_cms_remark_start_to_end_time_secs; // Between start and end of the most recent MS STW marking phase double _latest_cms_ms_marking_start_to_end_time_secs; // Pause time timers static elapsedTimer _STW_timer; // Concurrent collection timer. Used for total of all concurrent phases // during 1 collection cycle. static elapsedTimer _concurrent_timer; // When the size of the generation is changed, the size // of the change will rounded up or down (depending on the // type of change) by this value. size_t _generation_alignment; // If this variable is true, the size of the young generation // may be changed in order to reduce the pause(s) of the // collection of the tenured generation in order to meet the // pause time goal. It is common to change the size of the // tenured generation in order to meet the pause time goal // for the tenured generation. With the CMS collector for // the tenured generation, the size of the young generation // can have an significant affect on the pause times for collecting the // tenured generation. // This is a duplicate of a variable in PSAdaptiveSizePolicy. It // is duplicated because it is not clear that it is general enough // to go into AdaptiveSizePolicy. int _change_young_gen_for_maj_pauses; // Variable that is set to true after a collection. bool _first_after_collection; // Fraction of collections that are of each type double concurrent_fraction() const; double STW_msc_fraction() const; double STW_ms_fraction() const; // This call cannot be put into the epilogue as long as some // of the counters can be set during concurrent phases. virtual void clear_generation_free_space_flags(); void set_first_after_collection() { _first_after_collection = true; } protected: // Average of the sum of the concurrent times for // one collection in seconds. AdaptiveWeightedAverage* _avg_concurrent_time; // Average time between concurrent collections in seconds. AdaptiveWeightedAverage* _avg_concurrent_interval; // Average cost of the concurrent part of a collection // in seconds. AdaptiveWeightedAverage* _avg_concurrent_gc_cost; // Average of the initial pause of a concurrent collection in seconds. AdaptivePaddedAverage* _avg_initial_pause; // Average of the remark pause of a concurrent collection in seconds. AdaptivePaddedAverage* _avg_remark_pause; // Average of the stop-the-world (STW) (initial mark + remark) // times in seconds for concurrent collections. AdaptiveWeightedAverage* _avg_cms_STW_time; // Average of the STW collection cost for concurrent collections. AdaptiveWeightedAverage* _avg_cms_STW_gc_cost; // Average of the bytes free at the start of the sweep. AdaptiveWeightedAverage* _avg_cms_free_at_sweep; // Average of the bytes free at the end of the collection. AdaptiveWeightedAverage* _avg_cms_free; // Average of the bytes promoted between cms collections. AdaptiveWeightedAverage* _avg_cms_promo; // stop-the-world (STW) mark-sweep-compact // Average of the pause time in seconds for STW mark-sweep-compact // collections. AdaptiveWeightedAverage* _avg_msc_pause; // Average of the interval in seconds between STW mark-sweep-compact // collections. AdaptiveWeightedAverage* _avg_msc_interval; // Average of the collection costs for STW mark-sweep-compact // collections. AdaptiveWeightedAverage* _avg_msc_gc_cost; // Averages for mark-sweep collections. // The collection may have started as a background collection // that completes in a stop-the-world (STW) collection. // Average of the pause time in seconds for mark-sweep // collections. AdaptiveWeightedAverage* _avg_ms_pause; // Average of the interval in seconds between mark-sweep // collections. AdaptiveWeightedAverage* _avg_ms_interval; // Average of the collection costs for mark-sweep // collections. AdaptiveWeightedAverage* _avg_ms_gc_cost; // These variables contain a linear fit of // a generation size as the independent variable // and a pause time as the dependent variable. // For example _remark_pause_old_estimator // is a fit of the old generation size as the // independent variable and the remark pause // as the dependent variable. // remark pause time vs. cms gen size LinearLeastSquareFit* _remark_pause_old_estimator; // initial pause time vs. cms gen size LinearLeastSquareFit* _initial_pause_old_estimator; // remark pause time vs. young gen size LinearLeastSquareFit* _remark_pause_young_estimator; // initial pause time vs. young gen size LinearLeastSquareFit* _initial_pause_young_estimator; // Accessors int processor_count() const { return _processor_count; } int concurrent_processor_count() const { return _concurrent_processor_count; } AdaptiveWeightedAverage* avg_concurrent_time() const { return _avg_concurrent_time; } AdaptiveWeightedAverage* avg_concurrent_interval() const { return _avg_concurrent_interval; } AdaptiveWeightedAverage* avg_concurrent_gc_cost() const { return _avg_concurrent_gc_cost; } AdaptiveWeightedAverage* avg_cms_STW_time() const { return _avg_cms_STW_time; } AdaptiveWeightedAverage* avg_cms_STW_gc_cost() const { return _avg_cms_STW_gc_cost; } AdaptivePaddedAverage* avg_initial_pause() const { return _avg_initial_pause; } AdaptivePaddedAverage* avg_remark_pause() const { return _avg_remark_pause; } AdaptiveWeightedAverage* avg_cms_free() const { return _avg_cms_free; } AdaptiveWeightedAverage* avg_cms_free_at_sweep() const { return _avg_cms_free_at_sweep; } AdaptiveWeightedAverage* avg_msc_pause() const { return _avg_msc_pause; } AdaptiveWeightedAverage* avg_msc_interval() const { return _avg_msc_interval; } AdaptiveWeightedAverage* avg_msc_gc_cost() const { return _avg_msc_gc_cost; } AdaptiveWeightedAverage* avg_ms_pause() const { return _avg_ms_pause; } AdaptiveWeightedAverage* avg_ms_interval() const { return _avg_ms_interval; } AdaptiveWeightedAverage* avg_ms_gc_cost() const { return _avg_ms_gc_cost; } LinearLeastSquareFit* remark_pause_old_estimator() { return _remark_pause_old_estimator; } LinearLeastSquareFit* initial_pause_old_estimator() { return _initial_pause_old_estimator; } LinearLeastSquareFit* remark_pause_young_estimator() { return _remark_pause_young_estimator; } LinearLeastSquareFit* initial_pause_young_estimator() { return _initial_pause_young_estimator; } // These *slope() methods return the slope // m for the linear fit of an independent // variable vs. a dependent variable. For // example // remark_pause = m * old_generation_size + c // These may be used to determine if an // adjustment should be made to achieve a goal. // For example, if remark_pause_old_slope() is // positive, a reduction of the old generation // size has on average resulted in the reduction // of the remark pause. float remark_pause_old_slope() { return _remark_pause_old_estimator->slope(); } float initial_pause_old_slope() { return _initial_pause_old_estimator->slope(); } float remark_pause_young_slope() { return _remark_pause_young_estimator->slope(); } float initial_pause_young_slope() { return _initial_pause_young_estimator->slope(); } // Update estimators void update_minor_pause_old_estimator(double minor_pause_in_ms); // Fraction of processors used by the concurrent phases. double concurrent_processor_fraction(); // Returns the total times for the concurrent part of the // latest collection in seconds. double concurrent_collection_time(); // Return the total times for the concurrent part of the // latest collection in seconds where the times of the various // concurrent phases are scaled by the processor fraction used // during the phase. double scaled_concurrent_collection_time(); // Dimensionless concurrent GC cost for all the concurrent phases. double concurrent_collection_cost(double interval_in_seconds); // Dimensionless GC cost double collection_cost(double pause_in_seconds, double interval_in_seconds); virtual GCPolicyKind kind() const { return _gc_cms_adaptive_size_policy; } virtual double time_since_major_gc() const; // This returns the maximum average for the concurrent, ms, and // msc collections. This is meant to be used for the calculation // of the decayed major gc cost and is not in general the // average of all the different types of major collections. virtual double major_gc_interval_average_for_decay() const; public: 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); // The timers for the stop-the-world phases measure a total // stop-the-world time. The timer is started and stopped // for each phase but is only reset after the final checkpoint. void checkpoint_roots_initial_begin(); void checkpoint_roots_initial_end(GCCause::Cause gc_cause); void checkpoint_roots_final_begin(); void checkpoint_roots_final_end(GCCause::Cause gc_cause); // Methods for gathering information about the // concurrent marking phase of the collection. // Records the mutator times and // resets the concurrent timer. void concurrent_marking_begin(); // Resets concurrent phase timer in the begin methods and // saves the time for a phase in the end methods. void concurrent_marking_end(); void concurrent_sweeping_begin(); void concurrent_sweeping_end(); // Similar to the above (e.g., concurrent_marking_end()) and // is used for both the precleaning an abortable precleaing // phases. void concurrent_precleaning_begin(); void concurrent_precleaning_end(); // Stops the concurrent phases time. Gathers // information and resets the timer. void concurrent_phases_end(GCCause::Cause gc_cause, size_t cur_eden, size_t cur_promo); // Methods for gather information about STW Mark-Sweep-Compact void msc_collection_begin(); void msc_collection_end(GCCause::Cause gc_cause); // Methods for gather information about Mark-Sweep done // in the foreground. void ms_collection_begin(); void ms_collection_end(GCCause::Cause gc_cause); // Cost for a mark-sweep tenured gen collection done in the foreground double ms_gc_cost() const { return MAX2(0.0F, _avg_ms_gc_cost->average()); } // Cost of collecting the tenured generation. Includes // concurrent collection and STW collection costs double cms_gc_cost() const; // Cost of STW mark-sweep-compact tenured gen collection. double msc_gc_cost() const { return MAX2(0.0F, _avg_msc_gc_cost->average()); } // double compacting_gc_cost() const { double result = MIN2(1.0, minor_gc_cost() + msc_gc_cost()); assert(result >= 0.0, "Both minor and major costs are non-negative"); return result; } // Restarts the concurrent phases timer. void concurrent_phases_resume(); // Time beginning and end of the marking phase for // a synchronous MS collection. A MS collection // that finishes in the foreground can have started // in the background. These methods capture the // completion of the marking (after the initial // marking) that is done in the foreground. void ms_collection_marking_begin(); void ms_collection_marking_end(GCCause::Cause gc_cause); static elapsedTimer* concurrent_timer_ptr() { return &_concurrent_timer; } AdaptiveWeightedAverage* avg_cms_promo() const { return _avg_cms_promo; } int change_young_gen_for_maj_pauses() { return _change_young_gen_for_maj_pauses; } void set_change_young_gen_for_maj_pauses(int v) { _change_young_gen_for_maj_pauses = v; } void clear_internal_time_intervals(); // Either calculated_promo_size_in_bytes() or promo_size() // should be deleted. size_t promo_size() { return _promo_size; } void set_promo_size(size_t v) { _promo_size = v; } // Cost of GC for all types of collections. virtual double gc_cost() const; size_t generation_alignment() { return _generation_alignment; } virtual void compute_eden_space_size(size_t cur_eden, size_t max_eden_size); // Calculates new survivor space size; returns a new tenuring threshold // value. Stores new survivor size in _survivor_size. virtual uint compute_survivor_space_size_and_threshold( bool is_survivor_overflow, uint tenuring_threshold, size_t survivor_limit); virtual void compute_tenured_generation_free_space(size_t cur_tenured_free, size_t max_tenured_available, size_t cur_eden); size_t eden_decrement_aligned_down(size_t cur_eden); size_t eden_increment_aligned_up(size_t cur_eden); size_t adjust_eden_for_pause_time(size_t cur_eden); size_t adjust_eden_for_throughput(size_t cur_eden); size_t adjust_eden_for_footprint(size_t cur_eden); size_t promo_decrement_aligned_down(size_t cur_promo); size_t promo_increment_aligned_up(size_t cur_promo); size_t adjust_promo_for_pause_time(size_t cur_promo); size_t adjust_promo_for_throughput(size_t cur_promo); size_t adjust_promo_for_footprint(size_t cur_promo, size_t cur_eden); // Scale down the input size by the ratio of the cost to collect the // generation to the total GC cost. size_t scale_by_gen_gc_cost(size_t base_change, double gen_gc_cost); // Return the value and clear it. bool get_and_clear_first_after_collection(); // Printing support virtual bool print_adaptive_size_policy_on(outputStream* st) const; }; #endif // SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_CMSADAPTIVESIZEPOLICY_HPP