rev 47449 : imported patch 8189666
rev 47451 : imported patch 8189729-perc-naming

   1 /*
   2  * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_G1_G1DEFAULTPOLICY_HPP
  26 #define SHARE_VM_GC_G1_G1DEFAULTPOLICY_HPP
  27 
  28 #include "gc/g1/g1CollectorState.hpp"
  29 #include "gc/g1/g1GCPhaseTimes.hpp"
  30 #include "gc/g1/g1InCSetState.hpp"
  31 #include "gc/g1/g1InitialMarkToMixedTimeTracker.hpp"
  32 #include "gc/g1/g1MMUTracker.hpp"
  33 #include "gc/g1/g1Predictions.hpp"
  34 #include "gc/g1/g1Policy.hpp"
  35 #include "gc/g1/g1YoungGenSizer.hpp"
  36 #include "gc/shared/gcCause.hpp"
  37 #include "utilities/pair.hpp"
  38 
  39 class HeapRegion;
  40 class G1CollectionSet;
  41 class CollectionSetChooser;
  42 class G1IHOPControl;
  43 class G1Analytics;
  44 class G1SurvivorRegions;
  45 class G1YoungGenSizer;
  46 class GCPolicyCounters;
  47 class STWGCTimer;
  48 
  49 class G1DefaultPolicy: public G1Policy {
  50  private:
  51 
  52   static G1IHOPControl* create_ihop_control(const G1Predictions* predictor);
  53   // Update the IHOP control with necessary statistics.
  54   void update_ihop_prediction(double mutator_time_s,
  55                               size_t mutator_alloc_bytes,
  56                               size_t young_gen_size);
  57   void report_ihop_statistics();
  58 
  59   G1Predictions _predictor;
  60   G1Analytics* _analytics;
  61   G1MMUTracker* _mmu_tracker;
  62   G1IHOPControl* _ihop_control;
  63 
  64   GCPolicyCounters* _policy_counters;
  65 
  66   double _full_collection_start_sec;
  67 
  68   jlong _collection_pause_end_millis;
  69 
  70   uint _young_list_target_length;
  71   uint _young_list_fixed_length;
  72 
  73   // The max number of regions we can extend the eden by while the GC
  74   // locker is active. This should be >= _young_list_target_length;
  75   uint _young_list_max_length;
  76 
  77   // SurvRateGroups below must be initialized after the predictor because they
  78   // indirectly use it through this object passed to their constructor.
  79   SurvRateGroup* _short_lived_surv_rate_group;
  80   SurvRateGroup* _survivor_surv_rate_group;
  81 
  82   double _reserve_factor;
  83   // This will be set when the heap is expanded
  84   // for the first time during initialization.
  85   uint   _reserve_regions;
  86 
  87   G1YoungGenSizer _young_gen_sizer;
  88 
  89   uint _free_regions_at_end_of_collection;
  90 
  91   size_t _max_rs_lengths;
  92 
  93   size_t _rs_lengths_prediction;
  94 
  95   size_t _pending_cards;
  96 
  97   // The amount of allocated bytes in old gen during the last mutator and the following
  98   // young GC phase.
  99   size_t _bytes_allocated_in_old_since_last_gc;
 100 
 101   G1InitialMarkToMixedTimeTracker _initial_mark_to_mixed;
 102 public:
 103   const G1Predictions& predictor() const { return _predictor; }
 104   const G1Analytics* analytics()   const { return const_cast<const G1Analytics*>(_analytics); }
 105 
 106   void add_bytes_allocated_in_old_since_last_gc(size_t bytes) { _bytes_allocated_in_old_since_last_gc += bytes; }
 107 
 108   void set_region_eden(HeapRegion* hr) {
 109     hr->set_eden();
 110     hr->install_surv_rate_group(_short_lived_surv_rate_group);
 111   }
 112 
 113   void set_region_survivor(HeapRegion* hr) {
 114     assert(hr->is_survivor(), "pre-condition");
 115     hr->install_surv_rate_group(_survivor_surv_rate_group);
 116   }
 117 
 118   void record_max_rs_lengths(size_t rs_lengths) {
 119     _max_rs_lengths = rs_lengths;
 120   }
 121 
 122 
 123   double predict_base_elapsed_time_ms(size_t pending_cards) const;
 124   double predict_base_elapsed_time_ms(size_t pending_cards,
 125                                       size_t scanned_cards) const;
 126   size_t predict_bytes_to_copy(HeapRegion* hr) const;
 127   double predict_region_elapsed_time_ms(HeapRegion* hr, bool for_young_gc) const;
 128 
 129   double predict_survivor_regions_evac_time() const;
 130 
 131   bool should_update_surv_rate_group_predictors() {
 132     return collector_state()->last_gc_was_young() && !collector_state()->in_marking_window();
 133   }
 134 
 135   void cset_regions_freed() {
 136     bool update = should_update_surv_rate_group_predictors();
 137 
 138     _short_lived_surv_rate_group->all_surviving_words_recorded(predictor(), update);
 139     _survivor_surv_rate_group->all_surviving_words_recorded(predictor(), update);
 140   }
 141 
 142   G1MMUTracker* mmu_tracker() {
 143     return _mmu_tracker;
 144   }
 145 
 146   const G1MMUTracker* mmu_tracker() const {
 147     return _mmu_tracker;
 148   }
 149 
 150   double max_pause_time_ms() const {
 151     return _mmu_tracker->max_gc_time() * 1000.0;
 152   }
 153 
 154   double predict_yg_surv_rate(int age, SurvRateGroup* surv_rate_group) const;
 155 
 156   double predict_yg_surv_rate(int age) const;
 157 
 158   double accum_yg_surv_rate_pred(int age) const;
 159 
 160 protected:
 161   G1CollectionSet* _collection_set;
 162   virtual double average_time_ms(G1GCPhaseTimes::GCParPhases phase) const;
 163   virtual double other_time_ms(double pause_time_ms) const;
 164 
 165   double young_other_time_ms() const;
 166   double non_young_other_time_ms() const;
 167   double constant_other_time_ms(double pause_time_ms) const;
 168 
 169   CollectionSetChooser* cset_chooser() const;
 170 private:
 171 
 172   // The number of bytes copied during the GC.
 173   size_t _bytes_copied_during_gc;
 174 
 175   // Stash a pointer to the g1 heap.
 176   G1CollectedHeap* _g1;
 177 
 178   G1GCPhaseTimes* _phase_times;
 179 
 180   // This set of variables tracks the collector efficiency, in order to
 181   // determine whether we should initiate a new marking.
 182   double _mark_remark_start_sec;
 183   double _mark_cleanup_start_sec;
 184 
 185   // Updates the internal young list maximum and target lengths. Returns the
 186   // unbounded young list target length.
 187   uint update_young_list_max_and_target_length();
 188   uint update_young_list_max_and_target_length(size_t rs_lengths);
 189 
 190   // Update the young list target length either by setting it to the
 191   // desired fixed value or by calculating it using G1's pause
 192   // prediction model. If no rs_lengths parameter is passed, predict
 193   // the RS lengths using the prediction model, otherwise use the
 194   // given rs_lengths as the prediction.
 195   // Returns the unbounded young list target length.
 196   uint update_young_list_target_length(size_t rs_lengths);
 197 
 198   // Calculate and return the minimum desired young list target
 199   // length. This is the minimum desired young list length according
 200   // to the user's inputs.
 201   uint calculate_young_list_desired_min_length(uint base_min_length) const;
 202 
 203   // Calculate and return the maximum desired young list target
 204   // length. This is the maximum desired young list length according
 205   // to the user's inputs.
 206   uint calculate_young_list_desired_max_length() const;
 207 
 208   // Calculate and return the maximum young list target length that
 209   // can fit into the pause time goal. The parameters are: rs_lengths
 210   // represent the prediction of how large the young RSet lengths will
 211   // be, base_min_length is the already existing number of regions in
 212   // the young list, min_length and max_length are the desired min and
 213   // max young list length according to the user's inputs.
 214   uint calculate_young_list_target_length(size_t rs_lengths,
 215                                           uint base_min_length,
 216                                           uint desired_min_length,
 217                                           uint desired_max_length) const;
 218 
 219   // Result of the bounded_young_list_target_length() method, containing both the
 220   // bounded as well as the unbounded young list target lengths in this order.
 221   typedef Pair<uint, uint, StackObj> YoungTargetLengths;
 222   YoungTargetLengths young_list_target_lengths(size_t rs_lengths) const;
 223 
 224   void update_rs_lengths_prediction();
 225   void update_rs_lengths_prediction(size_t prediction);
 226 
 227   // Check whether a given young length (young_length) fits into the
 228   // given target pause time and whether the prediction for the amount
 229   // of objects to be copied for the given length will fit into the
 230   // given free space (expressed by base_free_regions).  It is used by
 231   // calculate_young_list_target_length().
 232   bool predict_will_fit(uint young_length, double base_time_ms,
 233                         uint base_free_regions, double target_pause_time_ms) const;
 234 
 235 public:
 236   size_t pending_cards() const { return _pending_cards; }
 237 
 238   uint calc_min_old_cset_length() const;
 239   uint calc_max_old_cset_length() const;
 240 
 241   // Returns the given amount of reclaimable bytes (that represents
 242   // the amount of reclaimable space still to be collected) as a
 243   // percentage of the current heap capacity.
 244   double reclaimable_bytes_perc(size_t reclaimable_bytes) const;
 245 
 246   jlong collection_pause_end_millis() { return _collection_pause_end_millis; }
 247 
 248 private:
 249   // Sets up marking if proper conditions are met.
 250   void maybe_start_marking();
 251 
 252   // The kind of STW pause.
 253   enum PauseKind {
 254     FullGC,
 255     YoungOnlyGC,
 256     MixedGC,
 257     LastYoungGC,
 258     InitialMarkGC,
 259     Cleanup,
 260     Remark
 261   };
 262 
 263   // Calculate PauseKind from internal state.
 264   PauseKind young_gc_pause_kind() const;
 265   // Record the given STW pause with the given start and end times (in s).
 266   void record_pause(PauseKind kind, double start, double end);
 267   // Indicate that we aborted marking before doing any mixed GCs.
 268   void abort_time_to_mixed_tracking();
 269 public:
 270 
 271   G1DefaultPolicy(STWGCTimer* gc_timer);
 272 
 273   virtual ~G1DefaultPolicy();
 274 
 275   G1CollectorState* collector_state() const;
 276 
 277   G1GCPhaseTimes* phase_times() const { return _phase_times; }
 278 
 279   void revise_young_list_target_length_if_necessary(size_t rs_lengths);
 280 
 281   void record_new_heap_size(uint new_number_of_regions);
 282 
 283   void init(G1CollectedHeap* g1h, G1CollectionSet* collection_set);
 284 
 285   virtual void note_gc_start();
 286 
 287   bool need_to_start_conc_mark(const char* source, size_t alloc_word_size = 0);
 288 
 289   bool about_to_start_mixed_phase() const;
 290 
 291   void record_collection_pause_start(double start_time_sec);
 292   void record_collection_pause_end(double pause_time_ms, size_t cards_scanned, size_t heap_used_bytes_before_gc);
 293 
 294   void record_full_collection_start();
 295   void record_full_collection_end();
 296 
 297   void record_concurrent_mark_init_end(double mark_init_elapsed_time_ms);
 298 
 299   void record_concurrent_mark_remark_start();
 300   void record_concurrent_mark_remark_end();
 301 
 302   void record_concurrent_mark_cleanup_start();
 303   void record_concurrent_mark_cleanup_end();
 304   void record_concurrent_mark_cleanup_completed();
 305 
 306   virtual void print_phases();
 307 
 308   void record_bytes_copied_during_gc(size_t bytes) {
 309     _bytes_copied_during_gc += bytes;
 310   }
 311 
 312   size_t bytes_copied_during_gc() const {
 313     return _bytes_copied_during_gc;
 314   }
 315 
 316   bool next_gc_should_be_mixed(const char* true_action_str,
 317                                const char* false_action_str) const;
 318 
 319   virtual void finalize_collection_set(double target_pause_time_ms, G1SurvivorRegions* survivor);
 320 private:
 321   // Set the state to start a concurrent marking cycle and clear
 322   // _initiate_conc_mark_if_possible because it has now been
 323   // acted on.
 324   void initiate_conc_mark();
 325 
 326 public:
 327   bool force_initial_mark_if_outside_cycle(GCCause::Cause gc_cause);
 328 
 329   void decide_on_conc_mark_initiation();
 330 
 331   void finished_recalculating_age_indexes(bool is_survivors) {
 332     if (is_survivors) {
 333       _survivor_surv_rate_group->finished_recalculating_age_indexes();
 334     } else {
 335       _short_lived_surv_rate_group->finished_recalculating_age_indexes();
 336     }
 337   }
 338 
 339   size_t young_list_target_length() const { return _young_list_target_length; }
 340 
 341   bool should_allocate_mutator_region() const;
 342 
 343   bool can_expand_young_list() const;
 344 
 345   uint young_list_max_length() const {
 346     return _young_list_max_length;
 347   }
 348 
 349   bool adaptive_young_list_length() const;
 350 
 351   virtual bool should_process_references() const {
 352     return true;
 353   }
 354 
 355   void transfer_survivors_to_cset(const G1SurvivorRegions* survivors);
 356 
 357 private:
 358   //
 359   // Survivor regions policy.
 360   //
 361 
 362   // Current tenuring threshold, set to 0 if the collector reaches the
 363   // maximum amount of survivors regions.
 364   uint _tenuring_threshold;
 365 
 366   // The limit on the number of regions allocated for survivors.
 367   uint _max_survivor_regions;
 368 
 369   AgeTable _survivors_age_table;
 370 
 371 protected:
 372   size_t desired_survivor_size() const;
 373 public:
 374   uint tenuring_threshold() const { return _tenuring_threshold; }
 375 
 376   uint max_survivor_regions() {
 377     return _max_survivor_regions;
 378   }
 379 
 380   void note_start_adding_survivor_regions() {
 381     _survivor_surv_rate_group->start_adding_regions();
 382   }
 383 
 384   void note_stop_adding_survivor_regions() {
 385     _survivor_surv_rate_group->stop_adding_regions();
 386   }
 387 
 388   void record_age_table(AgeTable* age_table) {
 389     _survivors_age_table.merge(age_table);
 390   }
 391 
 392   void print_age_table();
 393 
 394   void update_max_gc_locker_expansion();
 395 
 396   void update_survivors_policy();
 397 };
 398 
 399 #endif // SHARE_VM_GC_G1_G1DEFAULTPOLICY_HPP
--- EOF ---