duke@435: /*
tamao@5120:  * Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSADAPTIVESIZEPOLICY_HPP
stefank@2314: #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSADAPTIVESIZEPOLICY_HPP
stefank@2314: 
stefank@2314: #include "gc_implementation/shared/adaptiveSizePolicy.hpp"
stefank@2314: #include "gc_implementation/shared/gcStats.hpp"
stefank@2314: #include "gc_implementation/shared/gcUtil.hpp"
stefank@2314: #include "gc_interface/gcCause.hpp"
stefank@2314: 
duke@435: // This class keeps statistical information and computes the
duke@435: // optimal free space for both the young and old generation
duke@435: // based on current application characteristics (based on gc cost
duke@435: // and application footprint).
duke@435: //
duke@435: // It also computes an optimal tenuring threshold between the young
duke@435: // and old generations, so as to equalize the cost of collections
duke@435: // of those generations, as well as optimial survivor space sizes
duke@435: // for the young generation.
duke@435: //
duke@435: // While this class is specifically intended for a generational system
duke@435: // consisting of a young gen (containing an Eden and two semi-spaces)
duke@435: // and a tenured gen, as well as a perm gen for reflective data, it
duke@435: // makes NO references to specific generations.
duke@435: //
duke@435: // 05/02/2003 Update
duke@435: // The 1.5 policy makes use of data gathered for the costs of GC on
duke@435: // specific generations.  That data does reference specific
duke@435: // generation.  Also diagnostics specific to generations have
duke@435: // been added.
duke@435: 
duke@435: // Forward decls
duke@435: class elapsedTimer;
duke@435: 
duke@435: class PSAdaptiveSizePolicy : public AdaptiveSizePolicy {
duke@435:  friend class PSGCAdaptivePolicyCounters;
duke@435:  private:
duke@435:   // These values are used to record decisions made during the
duke@435:   // policy.  For example, if the young generation was decreased
duke@435:   // to decrease the GC cost of minor collections the value
duke@435:   // decrease_young_gen_for_throughput_true is used.
duke@435: 
duke@435:   // Last calculated sizes, in bytes, and aligned
duke@435:   // NEEDS_CLEANUP should use sizes.hpp,  but it works in ints, not size_t's
duke@435: 
duke@435:   // Time statistics
duke@435:   AdaptivePaddedAverage* _avg_major_pause;
duke@435: 
duke@435:   // Footprint statistics
duke@435:   AdaptiveWeightedAverage* _avg_base_footprint;
duke@435: 
duke@435:   // Statistical data gathered for GC
duke@435:   GCStats _gc_stats;
duke@435: 
duke@435:   size_t _survivor_size_limit;   // Limit in bytes of survivor size
duke@435:   const double _collection_cost_margin_fraction;
duke@435: 
duke@435:   // Variable for estimating the major and minor pause times.
duke@435:   // These variables represent linear least-squares fits of
duke@435:   // the data.
duke@435:   //   major pause time vs. old gen size
duke@435:   LinearLeastSquareFit* _major_pause_old_estimator;
duke@435:   //   major pause time vs. young gen size
duke@435:   LinearLeastSquareFit* _major_pause_young_estimator;
duke@435: 
duke@435: 
duke@435:   // These record the most recent collection times.  They
duke@435:   // are available as an alternative to using the averages
duke@435:   // for making ergonomic decisions.
duke@435:   double _latest_major_mutator_interval_seconds;
duke@435: 
jwilhelm@6085:   const size_t _space_alignment; // alignment for eden, survivors
duke@435: 
duke@435:   const double _gc_minor_pause_goal_sec;    // goal for maximum minor gc pause
duke@435: 
duke@435:   // The amount of live data in the heap at the last full GC, used
duke@435:   // as a baseline to help us determine when we need to perform the
duke@435:   // next full GC.
duke@435:   size_t _live_at_last_full_gc;
duke@435: 
duke@435:   // decrease/increase the old generation for minor pause time
duke@435:   int _change_old_gen_for_min_pauses;
duke@435: 
duke@435:   // increase/decrease the young generation for major pause time
duke@435:   int _change_young_gen_for_maj_pauses;
duke@435: 
duke@435: 
duke@435:   // Flag indicating that the adaptive policy is ready to use
duke@435:   bool _old_gen_policy_is_ready;
duke@435: 
duke@435:   // Changing the generation sizing depends on the data that is
duke@435:   // gathered about the effects of changes on the pause times and
duke@435:   // throughput.  These variable count the number of data points
duke@435:   // gathered.  The policy may use these counters as a threshhold
duke@435:   // for reliable data.
duke@435:   julong _young_gen_change_for_major_pause_count;
duke@435: 
duke@435:   // To facilitate faster growth at start up, supplement the normal
duke@435:   // growth percentage for the young gen eden and the
duke@435:   // old gen space for promotion with these value which decay
duke@435:   // with increasing collections.
duke@435:   uint _young_gen_size_increment_supplement;
duke@435:   uint _old_gen_size_increment_supplement;
duke@435: 
duke@435:   // The number of bytes absorbed from eden into the old gen by moving the
duke@435:   // boundary over live data.
duke@435:   size_t _bytes_absorbed_from_eden;
duke@435: 
duke@435:  private:
duke@435: 
duke@435:   // Accessors
duke@435:   AdaptivePaddedAverage* avg_major_pause() const { return _avg_major_pause; }
duke@435:   double gc_minor_pause_goal_sec() const { return _gc_minor_pause_goal_sec; }
duke@435: 
duke@435:   // Change the young generation size to achieve a minor GC pause time goal
tamao@5120:   void adjust_promo_for_minor_pause_time(bool is_full_gc,
duke@435:                                    size_t* desired_promo_size_ptr,
duke@435:                                    size_t* desired_eden_size_ptr);
tamao@5120:   void adjust_eden_for_minor_pause_time(bool is_full_gc,
tamao@5120:                                    size_t* desired_eden_size_ptr);
duke@435:   // Change the generation sizes to achieve a GC pause time goal
duke@435:   // Returned sizes are not necessarily aligned.
tamao@5120:   void adjust_promo_for_pause_time(bool is_full_gc,
tamao@5120:                          size_t* desired_promo_size_ptr,
tamao@5120:                          size_t* desired_eden_size_ptr);
tamao@5120:   void adjust_eden_for_pause_time(bool is_full_gc,
duke@435:                          size_t* desired_promo_size_ptr,
duke@435:                          size_t* desired_eden_size_ptr);
duke@435:   // Change the generation sizes to achieve an application throughput goal
duke@435:   // Returned sizes are not necessarily aligned.
tamao@5120:   void adjust_promo_for_throughput(bool is_full_gc,
tamao@5120:                              size_t* desired_promo_size_ptr);
tamao@5120:   void adjust_eden_for_throughput(bool is_full_gc,
duke@435:                              size_t* desired_eden_size_ptr);
duke@435:   // Change the generation sizes to achieve minimum footprint
duke@435:   // Returned sizes are not aligned.
duke@435:   size_t adjust_promo_for_footprint(size_t desired_promo_size,
duke@435:                                     size_t desired_total);
duke@435:   size_t adjust_eden_for_footprint(size_t desired_promo_size,
duke@435:                                    size_t desired_total);
duke@435: 
duke@435:   // Size in bytes for an increment or decrement of eden.
duke@435:   virtual size_t eden_increment(size_t cur_eden, uint percent_change);
duke@435:   virtual size_t eden_decrement(size_t cur_eden);
duke@435:   size_t eden_decrement_aligned_down(size_t cur_eden);
duke@435:   size_t eden_increment_with_supplement_aligned_up(size_t cur_eden);
duke@435: 
duke@435:   // Size in bytes for an increment or decrement of the promotion area
duke@435:   virtual size_t promo_increment(size_t cur_promo, uint percent_change);
duke@435:   virtual size_t promo_decrement(size_t cur_promo);
duke@435:   size_t promo_decrement_aligned_down(size_t cur_promo);
duke@435:   size_t promo_increment_with_supplement_aligned_up(size_t cur_promo);
duke@435: 
duke@435:   // Returns a change that has been scaled down.  Result
duke@435:   // is not aligned.  (If useful, move to some shared
duke@435:   // location.)
duke@435:   size_t scale_down(size_t change, double part, double total);
duke@435: 
duke@435:  protected:
duke@435:   // Time accessors
duke@435: 
duke@435:   // Footprint accessors
duke@435:   size_t live_space() const {
duke@435:     return (size_t)(avg_base_footprint()->average() +
duke@435:                     avg_young_live()->average() +
duke@435:                     avg_old_live()->average());
duke@435:   }
duke@435:   size_t free_space() const {
duke@435:     return _eden_size + _promo_size;
duke@435:   }
duke@435: 
duke@435:   void set_promo_size(size_t new_size) {
duke@435:     _promo_size = new_size;
duke@435:   }
duke@435:   void set_survivor_size(size_t new_size) {
duke@435:     _survivor_size = new_size;
duke@435:   }
duke@435: 
duke@435:   // Update estimators
duke@435:   void update_minor_pause_old_estimator(double minor_pause_in_ms);
duke@435: 
duke@435:   virtual GCPolicyKind kind() const { return _gc_ps_adaptive_size_policy; }
duke@435: 
duke@435:  public:
duke@435:   // Use by ASPSYoungGen and ASPSOldGen to limit boundary moving.
duke@435:   size_t eden_increment_aligned_up(size_t cur_eden);
duke@435:   size_t eden_increment_aligned_down(size_t cur_eden);
duke@435:   size_t promo_increment_aligned_up(size_t cur_promo);
duke@435:   size_t promo_increment_aligned_down(size_t cur_promo);
duke@435: 
duke@435:   virtual size_t eden_increment(size_t cur_eden);
duke@435:   virtual size_t promo_increment(size_t cur_promo);
duke@435: 
duke@435:   // Accessors for use by performance counters
duke@435:   AdaptivePaddedNoZeroDevAverage*  avg_promoted() const {
duke@435:     return _gc_stats.avg_promoted();
duke@435:   }
duke@435:   AdaptiveWeightedAverage* avg_base_footprint() const {
duke@435:     return _avg_base_footprint;
duke@435:   }
duke@435: 
duke@435:   // Input arguments are initial free space sizes for young and old
duke@435:   // generations, the initial survivor space size, the
duke@435:   // alignment values and the pause & throughput goals.
duke@435:   //
duke@435:   // NEEDS_CLEANUP this is a singleton object
duke@435:   PSAdaptiveSizePolicy(size_t init_eden_size,
duke@435:                        size_t init_promo_size,
duke@435:                        size_t init_survivor_size,
jwilhelm@6085:                        size_t space_alignment,
duke@435:                        double gc_pause_goal_sec,
duke@435:                        double gc_minor_pause_goal_sec,
duke@435:                        uint gc_time_ratio);
duke@435: 
duke@435:   // Methods indicating events of interest to the adaptive size policy,
duke@435:   // called by GC algorithms. It is the responsibility of users of this
duke@435:   // policy to call these methods at the correct times!
duke@435:   void major_collection_begin();
duke@435:   void major_collection_end(size_t amount_live, GCCause::Cause gc_cause);
duke@435: 
duke@435:   void tenured_allocation(size_t size) {
duke@435:     _avg_pretenured->sample(size);
duke@435:   }
duke@435: 
duke@435:   // Accessors
duke@435:   // NEEDS_CLEANUP   should use sizes.hpp
duke@435: 
jwilhelm@6267:   static size_t calculate_free_based_on_live(size_t live, uintx ratio_as_percentage);
jwilhelm@6267: 
jwilhelm@6267:   size_t calculated_old_free_size_in_bytes() const;
duke@435: 
duke@435:   size_t average_old_live_in_bytes() const {
duke@435:     return (size_t) avg_old_live()->average();
duke@435:   }
duke@435: 
duke@435:   size_t average_promoted_in_bytes() const {
duke@435:     return (size_t)avg_promoted()->average();
duke@435:   }
duke@435: 
duke@435:   size_t padded_average_promoted_in_bytes() const {
duke@435:     return (size_t)avg_promoted()->padded_average();
duke@435:   }
duke@435: 
duke@435:   int change_young_gen_for_maj_pauses() {
duke@435:     return _change_young_gen_for_maj_pauses;
duke@435:   }
duke@435:   void set_change_young_gen_for_maj_pauses(int v) {
duke@435:     _change_young_gen_for_maj_pauses = v;
duke@435:   }
duke@435: 
duke@435:   int change_old_gen_for_min_pauses() {
duke@435:     return _change_old_gen_for_min_pauses;
duke@435:   }
duke@435:   void set_change_old_gen_for_min_pauses(int v) {
duke@435:     _change_old_gen_for_min_pauses = v;
duke@435:   }
duke@435: 
duke@435:   // Return true if the old generation size was changed
duke@435:   // to try to reach a pause time goal.
duke@435:   bool old_gen_changed_for_pauses() {
duke@435:     bool result = _change_old_gen_for_maj_pauses != 0 ||
duke@435:                   _change_old_gen_for_min_pauses != 0;
duke@435:     return result;
duke@435:   }
duke@435: 
duke@435:   // Return true if the young generation size was changed
duke@435:   // to try to reach a pause time goal.
duke@435:   bool young_gen_changed_for_pauses() {
duke@435:     bool result = _change_young_gen_for_min_pauses != 0 ||
duke@435:                   _change_young_gen_for_maj_pauses != 0;
duke@435:     return result;
duke@435:   }
duke@435:   // end flags for pause goal
duke@435: 
duke@435:   // Return true if the old generation size was changed
duke@435:   // to try to reach a throughput goal.
duke@435:   bool old_gen_changed_for_throughput() {
duke@435:     bool result = _change_old_gen_for_throughput != 0;
duke@435:     return result;
duke@435:   }
duke@435: 
duke@435:   // Return true if the young generation size was changed
duke@435:   // to try to reach a throughput goal.
duke@435:   bool young_gen_changed_for_throughput() {
duke@435:     bool result = _change_young_gen_for_throughput != 0;
duke@435:     return result;
duke@435:   }
duke@435: 
duke@435:   int decrease_for_footprint() { return _decrease_for_footprint; }
duke@435: 
duke@435: 
duke@435:   // Accessors for estimators.  The slope of the linear fit is
duke@435:   // currently all that is used for making decisions.
duke@435: 
duke@435:   LinearLeastSquareFit* major_pause_old_estimator() {
duke@435:     return _major_pause_old_estimator;
duke@435:   }
duke@435: 
duke@435:   LinearLeastSquareFit* major_pause_young_estimator() {
duke@435:     return _major_pause_young_estimator;
duke@435:   }
duke@435: 
duke@435: 
duke@435:   virtual void clear_generation_free_space_flags();
duke@435: 
duke@435:   float major_pause_old_slope() { return _major_pause_old_estimator->slope(); }
duke@435:   float major_pause_young_slope() {
duke@435:     return _major_pause_young_estimator->slope();
duke@435:   }
duke@435:   float major_collection_slope() { return _major_collection_estimator->slope();}
duke@435: 
duke@435:   bool old_gen_policy_is_ready() { return _old_gen_policy_is_ready; }
duke@435: 
duke@435:   // Given the amount of live data in the heap, should we
duke@435:   // perform a Full GC?
duke@435:   bool should_full_GC(size_t live_in_old_gen);
duke@435: 
tamao@5120:   // Calculates optimal (free) space sizes for both the young and old
duke@435:   // generations.  Stores results in _eden_size and _promo_size.
duke@435:   // Takes current used space in all generations as input, as well
duke@435:   // as an indication if a full gc has just been performed, for use
duke@435:   // in deciding if an OOM error should be thrown.
tamao@5192:   void compute_generations_free_space(size_t young_live,
tamao@5192:                                       size_t eden_live,
tamao@5192:                                       size_t old_live,
tamao@5192:                                       size_t cur_eden,  // current eden in bytes
tamao@5192:                                       size_t max_old_gen_size,
tamao@5192:                                       size_t max_eden_size,
tamao@5192:                                       bool   is_full_gc);
tamao@5120: 
tamao@5120:   void compute_eden_space_size(size_t young_live,
tamao@5120:                                size_t eden_live,
tamao@5120:                                size_t cur_eden,  // current eden in bytes
tamao@5120:                                size_t max_eden_size,
tamao@5120:                                bool   is_full_gc);
tamao@5120: 
tamao@5120:   void compute_old_gen_free_space(size_t old_live,
tamao@5120:                                              size_t cur_eden,  // current eden in bytes
tamao@5120:                                              size_t max_old_gen_size,
tamao@5120:                                              bool   is_full_gc);
duke@435: 
duke@435:   // Calculates new survivor space size;  returns a new tenuring threshold
duke@435:   // value. Stores new survivor size in _survivor_size.
jwilhelm@4129:   uint compute_survivor_space_size_and_threshold(bool   is_survivor_overflow,
jwilhelm@4129:                                                  uint    tenuring_threshold,
jwilhelm@4129:                                                  size_t survivor_limit);
duke@435: 
duke@435:   // Return the maximum size of a survivor space if the young generation were of
duke@435:   // size gen_size.
duke@435:   size_t max_survivor_size(size_t gen_size) {
duke@435:     // Never allow the target survivor size to grow more than MinSurvivorRatio
duke@435:     // of the young generation size.  We cannot grow into a two semi-space
duke@435:     // system, with Eden zero sized.  Even if the survivor space grows, from()
duke@435:     // might grow by moving the bottom boundary "down" -- so from space will
duke@435:     // remain almost full anyway (top() will be near end(), but there will be a
duke@435:     // large filler object at the bottom).
duke@435:     const size_t sz = gen_size / MinSurvivorRatio;
jwilhelm@6085:     const size_t alignment = _space_alignment;
duke@435:     return sz > alignment ? align_size_down(sz, alignment) : alignment;
duke@435:   }
duke@435: 
duke@435:   size_t live_at_last_full_gc() {
duke@435:     return _live_at_last_full_gc;
duke@435:   }
duke@435: 
duke@435:   size_t bytes_absorbed_from_eden() const { return _bytes_absorbed_from_eden; }
duke@435:   void   reset_bytes_absorbed_from_eden() { _bytes_absorbed_from_eden = 0; }
duke@435: 
duke@435:   void set_bytes_absorbed_from_eden(size_t val) {
duke@435:     _bytes_absorbed_from_eden = val;
duke@435:   }
duke@435: 
duke@435:   // Update averages that are always used (even
duke@435:   // if adaptive sizing is turned off).
duke@435:   void update_averages(bool is_survivor_overflow,
duke@435:                        size_t survived,
duke@435:                        size_t promoted);
duke@435: 
duke@435:   // Printing support
duke@435:   virtual bool print_adaptive_size_policy_on(outputStream* st) const;
tamao@5120: 
tamao@5120:   // Decay the supplemental growth additive.
tamao@5120:   void decay_supplemental_growth(bool is_full_gc);
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSADAPTIVESIZEPOLICY_HPP