Mercurial > hg > truffle
annotate src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp @ 677:96b229c54d1e
6543938: G1: remove the concept of popularity
Reviewed-by: iveresov, tonyp
| author | apetrusenko |
|---|---|
| date | Wed, 25 Mar 2009 13:10:54 -0700 |
| parents | 7bb995fbd3c0 |
| children | 315a5d70b295 |
| rev | line source |
|---|---|
| 342 | 1 /* |
| 579 | 2 * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved. |
| 342 | 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 // A G1CollectorPolicy makes policy decisions that determine the | |
| 26 // characteristics of the collector. Examples include: | |
| 27 // * choice of collection set. | |
| 28 // * when to collect. | |
| 29 | |
| 30 class HeapRegion; | |
| 31 class CollectionSetChooser; | |
| 32 | |
| 33 // Yes, this is a bit unpleasant... but it saves replicating the same thing | |
| 34 // over and over again and introducing subtle problems through small typos and | |
| 35 // cutting and pasting mistakes. The macros below introduces a number | |
| 36 // sequnce into the following two classes and the methods that access it. | |
| 37 | |
| 38 #define define_num_seq(name) \ | |
| 39 private: \ | |
| 40 NumberSeq _all_##name##_times_ms; \ | |
| 41 public: \ | |
| 42 void record_##name##_time_ms(double ms) { \ | |
| 43 _all_##name##_times_ms.add(ms); \ | |
| 44 } \ | |
| 45 NumberSeq* get_##name##_seq() { \ | |
| 46 return &_all_##name##_times_ms; \ | |
| 47 } | |
| 48 | |
| 49 class MainBodySummary; | |
| 50 | |
|
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51 class PauseSummary: public CHeapObj { |
| 342 | 52 define_num_seq(total) |
| 53 define_num_seq(other) | |
| 54 | |
| 55 public: | |
| 56 virtual MainBodySummary* main_body_summary() { return NULL; } | |
| 57 }; | |
| 58 | |
|
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59 class MainBodySummary: public CHeapObj { |
| 342 | 60 define_num_seq(satb_drain) // optional |
| 61 define_num_seq(parallel) // parallel only | |
| 62 define_num_seq(ext_root_scan) | |
| 63 define_num_seq(mark_stack_scan) | |
| 64 define_num_seq(scan_only) | |
| 65 define_num_seq(update_rs) | |
| 66 define_num_seq(scan_rs) | |
| 67 define_num_seq(scan_new_refs) // Only for temp use; added to | |
| 68 // in parallel case. | |
| 69 define_num_seq(obj_copy) | |
| 70 define_num_seq(termination) // parallel only | |
| 71 define_num_seq(parallel_other) // parallel only | |
| 72 define_num_seq(mark_closure) | |
| 73 define_num_seq(clear_ct) // parallel only | |
| 74 }; | |
| 75 | |
| 677 | 76 class Summary: public PauseSummary, |
| 77 public MainBodySummary { | |
| 342 | 78 public: |
| 79 virtual MainBodySummary* main_body_summary() { return this; } | |
| 80 }; | |
| 81 | |
| 677 | 82 class AbandonedSummary: public PauseSummary { |
| 342 | 83 }; |
| 84 | |
| 85 class G1CollectorPolicy: public CollectorPolicy { | |
| 86 protected: | |
| 87 // The number of pauses during the execution. | |
| 88 long _n_pauses; | |
| 89 | |
| 90 // either equal to the number of parallel threads, if ParallelGCThreads | |
| 91 // has been set, or 1 otherwise | |
| 92 int _parallel_gc_threads; | |
| 93 | |
| 94 enum SomePrivateConstants { | |
| 95 NumPrevPausesForHeuristics = 10, | |
| 96 NumPrevGCsForHeuristics = 10, | |
| 97 NumAPIs = HeapRegion::MaxAge | |
| 98 }; | |
| 99 | |
| 100 G1MMUTracker* _mmu_tracker; | |
| 101 | |
| 102 void initialize_flags(); | |
| 103 | |
| 104 void initialize_all() { | |
| 105 initialize_flags(); | |
| 106 initialize_size_info(); | |
| 107 initialize_perm_generation(PermGen::MarkSweepCompact); | |
| 108 } | |
| 109 | |
| 110 virtual size_t default_init_heap_size() { | |
| 111 // Pick some reasonable default. | |
| 112 return 8*M; | |
| 113 } | |
| 114 | |
| 115 | |
| 116 double _cur_collection_start_sec; | |
| 117 size_t _cur_collection_pause_used_at_start_bytes; | |
| 118 size_t _cur_collection_pause_used_regions_at_start; | |
| 119 size_t _prev_collection_pause_used_at_end_bytes; | |
| 120 double _cur_collection_par_time_ms; | |
| 121 double _cur_satb_drain_time_ms; | |
| 122 double _cur_clear_ct_time_ms; | |
| 123 bool _satb_drain_time_set; | |
| 124 | |
| 125 double _cur_CH_strong_roots_end_sec; | |
| 126 double _cur_CH_strong_roots_dur_ms; | |
| 127 double _cur_G1_strong_roots_end_sec; | |
| 128 double _cur_G1_strong_roots_dur_ms; | |
| 129 | |
| 130 // Statistics for recent GC pauses. See below for how indexed. | |
| 131 TruncatedSeq* _recent_CH_strong_roots_times_ms; | |
| 132 TruncatedSeq* _recent_G1_strong_roots_times_ms; | |
| 133 TruncatedSeq* _recent_evac_times_ms; | |
| 134 // These exclude marking times. | |
| 135 TruncatedSeq* _recent_pause_times_ms; | |
| 136 TruncatedSeq* _recent_gc_times_ms; | |
| 137 | |
| 138 TruncatedSeq* _recent_CS_bytes_used_before; | |
| 139 TruncatedSeq* _recent_CS_bytes_surviving; | |
| 140 | |
| 141 TruncatedSeq* _recent_rs_sizes; | |
| 142 | |
| 143 TruncatedSeq* _concurrent_mark_init_times_ms; | |
| 144 TruncatedSeq* _concurrent_mark_remark_times_ms; | |
| 145 TruncatedSeq* _concurrent_mark_cleanup_times_ms; | |
| 146 | |
| 677 | 147 Summary* _summary; |
| 148 AbandonedSummary* _abandoned_summary; | |
| 342 | 149 |
| 150 NumberSeq* _all_pause_times_ms; | |
| 151 NumberSeq* _all_full_gc_times_ms; | |
| 152 double _stop_world_start; | |
| 153 NumberSeq* _all_stop_world_times_ms; | |
| 154 NumberSeq* _all_yield_times_ms; | |
| 155 | |
| 156 size_t _region_num_young; | |
| 157 size_t _region_num_tenured; | |
| 158 size_t _prev_region_num_young; | |
| 159 size_t _prev_region_num_tenured; | |
| 160 | |
| 161 NumberSeq* _all_mod_union_times_ms; | |
| 162 | |
| 163 int _aux_num; | |
| 164 NumberSeq* _all_aux_times_ms; | |
| 165 double* _cur_aux_start_times_ms; | |
| 166 double* _cur_aux_times_ms; | |
| 167 bool* _cur_aux_times_set; | |
| 168 | |
| 169 double* _par_last_ext_root_scan_times_ms; | |
| 170 double* _par_last_mark_stack_scan_times_ms; | |
| 171 double* _par_last_scan_only_times_ms; | |
| 172 double* _par_last_scan_only_regions_scanned; | |
| 173 double* _par_last_update_rs_start_times_ms; | |
| 174 double* _par_last_update_rs_times_ms; | |
| 175 double* _par_last_update_rs_processed_buffers; | |
| 176 double* _par_last_scan_rs_start_times_ms; | |
| 177 double* _par_last_scan_rs_times_ms; | |
| 178 double* _par_last_scan_new_refs_times_ms; | |
| 179 double* _par_last_obj_copy_times_ms; | |
| 180 double* _par_last_termination_times_ms; | |
| 181 | |
| 182 // indicates that we are in young GC mode | |
| 183 bool _in_young_gc_mode; | |
| 184 | |
| 185 // indicates whether we are in full young or partially young GC mode | |
| 186 bool _full_young_gcs; | |
| 187 | |
| 188 // if true, then it tries to dynamically adjust the length of the | |
| 189 // young list | |
| 190 bool _adaptive_young_list_length; | |
| 191 size_t _young_list_min_length; | |
| 192 size_t _young_list_target_length; | |
| 193 size_t _young_list_so_prefix_length; | |
| 194 size_t _young_list_fixed_length; | |
| 195 | |
| 196 size_t _young_cset_length; | |
| 197 bool _last_young_gc_full; | |
| 198 | |
| 199 double _target_pause_time_ms; | |
| 200 | |
| 201 unsigned _full_young_pause_num; | |
| 202 unsigned _partial_young_pause_num; | |
| 203 | |
| 204 bool _during_marking; | |
| 205 bool _in_marking_window; | |
| 206 bool _in_marking_window_im; | |
| 207 | |
| 208 SurvRateGroup* _short_lived_surv_rate_group; | |
| 209 SurvRateGroup* _survivor_surv_rate_group; | |
| 210 // add here any more surv rate groups | |
| 211 | |
| 212 bool during_marking() { | |
| 213 return _during_marking; | |
| 214 } | |
| 215 | |
| 216 // <NEW PREDICTION> | |
| 217 | |
| 218 private: | |
| 219 enum PredictionConstants { | |
| 220 TruncatedSeqLength = 10 | |
| 221 }; | |
| 222 | |
| 223 TruncatedSeq* _alloc_rate_ms_seq; | |
| 224 double _prev_collection_pause_end_ms; | |
| 225 | |
| 226 TruncatedSeq* _pending_card_diff_seq; | |
| 227 TruncatedSeq* _rs_length_diff_seq; | |
| 228 TruncatedSeq* _cost_per_card_ms_seq; | |
| 229 TruncatedSeq* _cost_per_scan_only_region_ms_seq; | |
| 230 TruncatedSeq* _fully_young_cards_per_entry_ratio_seq; | |
| 231 TruncatedSeq* _partially_young_cards_per_entry_ratio_seq; | |
| 232 TruncatedSeq* _cost_per_entry_ms_seq; | |
| 233 TruncatedSeq* _partially_young_cost_per_entry_ms_seq; | |
| 234 TruncatedSeq* _cost_per_byte_ms_seq; | |
| 235 TruncatedSeq* _constant_other_time_ms_seq; | |
| 236 TruncatedSeq* _young_other_cost_per_region_ms_seq; | |
| 237 TruncatedSeq* _non_young_other_cost_per_region_ms_seq; | |
| 238 | |
| 239 TruncatedSeq* _pending_cards_seq; | |
| 240 TruncatedSeq* _scanned_cards_seq; | |
| 241 TruncatedSeq* _rs_lengths_seq; | |
| 242 | |
| 243 TruncatedSeq* _cost_per_byte_ms_during_cm_seq; | |
| 244 TruncatedSeq* _cost_per_scan_only_region_ms_during_cm_seq; | |
| 245 | |
| 246 TruncatedSeq* _young_gc_eff_seq; | |
| 247 | |
| 248 TruncatedSeq* _max_conc_overhead_seq; | |
| 249 | |
| 250 size_t _recorded_young_regions; | |
| 251 size_t _recorded_scan_only_regions; | |
| 252 size_t _recorded_non_young_regions; | |
| 253 size_t _recorded_region_num; | |
| 254 | |
| 255 size_t _free_regions_at_end_of_collection; | |
| 256 size_t _scan_only_regions_at_end_of_collection; | |
| 257 | |
| 258 size_t _recorded_rs_lengths; | |
| 259 size_t _max_rs_lengths; | |
| 260 | |
| 261 size_t _recorded_marked_bytes; | |
| 262 size_t _recorded_young_bytes; | |
| 263 | |
| 264 size_t _predicted_pending_cards; | |
| 265 size_t _predicted_cards_scanned; | |
| 266 size_t _predicted_rs_lengths; | |
| 267 size_t _predicted_bytes_to_copy; | |
| 268 | |
| 269 double _predicted_survival_ratio; | |
| 270 double _predicted_rs_update_time_ms; | |
| 271 double _predicted_rs_scan_time_ms; | |
| 272 double _predicted_scan_only_scan_time_ms; | |
| 273 double _predicted_object_copy_time_ms; | |
| 274 double _predicted_constant_other_time_ms; | |
| 275 double _predicted_young_other_time_ms; | |
| 276 double _predicted_non_young_other_time_ms; | |
| 277 double _predicted_pause_time_ms; | |
| 278 | |
| 279 double _vtime_diff_ms; | |
| 280 | |
| 281 double _recorded_young_free_cset_time_ms; | |
| 282 double _recorded_non_young_free_cset_time_ms; | |
| 283 | |
| 284 double _sigma; | |
| 285 double _expensive_region_limit_ms; | |
| 286 | |
| 287 size_t _rs_lengths_prediction; | |
| 288 | |
| 289 size_t _known_garbage_bytes; | |
| 290 double _known_garbage_ratio; | |
| 291 | |
| 292 double sigma() { | |
| 293 return _sigma; | |
| 294 } | |
| 295 | |
| 296 // A function that prevents us putting too much stock in small sample | |
| 297 // sets. Returns a number between 2.0 and 1.0, depending on the number | |
| 298 // of samples. 5 or more samples yields one; fewer scales linearly from | |
| 299 // 2.0 at 1 sample to 1.0 at 5. | |
| 300 double confidence_factor(int samples) { | |
| 301 if (samples > 4) return 1.0; | |
| 302 else return 1.0 + sigma() * ((double)(5 - samples))/2.0; | |
| 303 } | |
| 304 | |
| 305 double get_new_neg_prediction(TruncatedSeq* seq) { | |
| 306 return seq->davg() - sigma() * seq->dsd(); | |
| 307 } | |
| 308 | |
| 309 #ifndef PRODUCT | |
| 310 bool verify_young_ages(HeapRegion* head, SurvRateGroup *surv_rate_group); | |
| 311 #endif // PRODUCT | |
| 312 | |
| 313 protected: | |
| 314 double _pause_time_target_ms; | |
| 315 double _recorded_young_cset_choice_time_ms; | |
| 316 double _recorded_non_young_cset_choice_time_ms; | |
| 317 bool _within_target; | |
| 318 size_t _pending_cards; | |
| 319 size_t _max_pending_cards; | |
| 320 | |
| 321 public: | |
| 322 | |
| 323 void set_region_short_lived(HeapRegion* hr) { | |
| 324 hr->install_surv_rate_group(_short_lived_surv_rate_group); | |
| 325 } | |
| 326 | |
| 327 void set_region_survivors(HeapRegion* hr) { | |
| 328 hr->install_surv_rate_group(_survivor_surv_rate_group); | |
| 329 } | |
| 330 | |
| 331 #ifndef PRODUCT | |
| 332 bool verify_young_ages(); | |
| 333 #endif // PRODUCT | |
| 334 | |
| 335 void tag_scan_only(size_t short_lived_scan_only_length); | |
| 336 | |
| 337 double get_new_prediction(TruncatedSeq* seq) { | |
| 338 return MAX2(seq->davg() + sigma() * seq->dsd(), | |
| 339 seq->davg() * confidence_factor(seq->num())); | |
| 340 } | |
| 341 | |
| 342 size_t young_cset_length() { | |
| 343 return _young_cset_length; | |
| 344 } | |
| 345 | |
| 346 void record_max_rs_lengths(size_t rs_lengths) { | |
| 347 _max_rs_lengths = rs_lengths; | |
| 348 } | |
| 349 | |
| 350 size_t predict_pending_card_diff() { | |
| 351 double prediction = get_new_neg_prediction(_pending_card_diff_seq); | |
| 352 if (prediction < 0.00001) | |
| 353 return 0; | |
| 354 else | |
| 355 return (size_t) prediction; | |
| 356 } | |
| 357 | |
| 358 size_t predict_pending_cards() { | |
| 359 size_t max_pending_card_num = _g1->max_pending_card_num(); | |
| 360 size_t diff = predict_pending_card_diff(); | |
| 361 size_t prediction; | |
| 362 if (diff > max_pending_card_num) | |
| 363 prediction = max_pending_card_num; | |
| 364 else | |
| 365 prediction = max_pending_card_num - diff; | |
| 366 | |
| 367 return prediction; | |
| 368 } | |
| 369 | |
| 370 size_t predict_rs_length_diff() { | |
| 371 return (size_t) get_new_prediction(_rs_length_diff_seq); | |
| 372 } | |
| 373 | |
| 374 double predict_alloc_rate_ms() { | |
| 375 return get_new_prediction(_alloc_rate_ms_seq); | |
| 376 } | |
| 377 | |
| 378 double predict_cost_per_card_ms() { | |
| 379 return get_new_prediction(_cost_per_card_ms_seq); | |
| 380 } | |
| 381 | |
| 382 double predict_rs_update_time_ms(size_t pending_cards) { | |
| 383 return (double) pending_cards * predict_cost_per_card_ms(); | |
| 384 } | |
| 385 | |
| 386 double predict_fully_young_cards_per_entry_ratio() { | |
| 387 return get_new_prediction(_fully_young_cards_per_entry_ratio_seq); | |
| 388 } | |
| 389 | |
| 390 double predict_partially_young_cards_per_entry_ratio() { | |
| 391 if (_partially_young_cards_per_entry_ratio_seq->num() < 2) | |
| 392 return predict_fully_young_cards_per_entry_ratio(); | |
| 393 else | |
| 394 return get_new_prediction(_partially_young_cards_per_entry_ratio_seq); | |
| 395 } | |
| 396 | |
| 397 size_t predict_young_card_num(size_t rs_length) { | |
| 398 return (size_t) ((double) rs_length * | |
| 399 predict_fully_young_cards_per_entry_ratio()); | |
| 400 } | |
| 401 | |
| 402 size_t predict_non_young_card_num(size_t rs_length) { | |
| 403 return (size_t) ((double) rs_length * | |
| 404 predict_partially_young_cards_per_entry_ratio()); | |
| 405 } | |
| 406 | |
| 407 double predict_rs_scan_time_ms(size_t card_num) { | |
| 408 if (full_young_gcs()) | |
| 409 return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq); | |
| 410 else | |
| 411 return predict_partially_young_rs_scan_time_ms(card_num); | |
| 412 } | |
| 413 | |
| 414 double predict_partially_young_rs_scan_time_ms(size_t card_num) { | |
| 415 if (_partially_young_cost_per_entry_ms_seq->num() < 3) | |
| 416 return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq); | |
| 417 else | |
| 418 return (double) card_num * | |
| 419 get_new_prediction(_partially_young_cost_per_entry_ms_seq); | |
| 420 } | |
| 421 | |
| 422 double predict_scan_only_time_ms_during_cm(size_t scan_only_region_num) { | |
| 423 if (_cost_per_scan_only_region_ms_during_cm_seq->num() < 3) | |
| 424 return 1.5 * (double) scan_only_region_num * | |
| 425 get_new_prediction(_cost_per_scan_only_region_ms_seq); | |
| 426 else | |
| 427 return (double) scan_only_region_num * | |
| 428 get_new_prediction(_cost_per_scan_only_region_ms_during_cm_seq); | |
| 429 } | |
| 430 | |
| 431 double predict_scan_only_time_ms(size_t scan_only_region_num) { | |
| 432 if (_in_marking_window_im) | |
| 433 return predict_scan_only_time_ms_during_cm(scan_only_region_num); | |
| 434 else | |
| 435 return (double) scan_only_region_num * | |
| 436 get_new_prediction(_cost_per_scan_only_region_ms_seq); | |
| 437 } | |
| 438 | |
| 439 double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) { | |
| 440 if (_cost_per_byte_ms_during_cm_seq->num() < 3) | |
| 441 return 1.1 * (double) bytes_to_copy * | |
| 442 get_new_prediction(_cost_per_byte_ms_seq); | |
| 443 else | |
| 444 return (double) bytes_to_copy * | |
| 445 get_new_prediction(_cost_per_byte_ms_during_cm_seq); | |
| 446 } | |
| 447 | |
| 448 double predict_object_copy_time_ms(size_t bytes_to_copy) { | |
| 449 if (_in_marking_window && !_in_marking_window_im) | |
| 450 return predict_object_copy_time_ms_during_cm(bytes_to_copy); | |
| 451 else | |
| 452 return (double) bytes_to_copy * | |
| 453 get_new_prediction(_cost_per_byte_ms_seq); | |
| 454 } | |
| 455 | |
| 456 double predict_constant_other_time_ms() { | |
| 457 return get_new_prediction(_constant_other_time_ms_seq); | |
| 458 } | |
| 459 | |
| 460 double predict_young_other_time_ms(size_t young_num) { | |
| 461 return | |
| 462 (double) young_num * | |
| 463 get_new_prediction(_young_other_cost_per_region_ms_seq); | |
| 464 } | |
| 465 | |
| 466 double predict_non_young_other_time_ms(size_t non_young_num) { | |
| 467 return | |
| 468 (double) non_young_num * | |
| 469 get_new_prediction(_non_young_other_cost_per_region_ms_seq); | |
| 470 } | |
| 471 | |
| 472 void check_if_region_is_too_expensive(double predicted_time_ms); | |
| 473 | |
| 474 double predict_young_collection_elapsed_time_ms(size_t adjustment); | |
| 475 double predict_base_elapsed_time_ms(size_t pending_cards); | |
| 476 double predict_base_elapsed_time_ms(size_t pending_cards, | |
| 477 size_t scanned_cards); | |
| 478 size_t predict_bytes_to_copy(HeapRegion* hr); | |
| 479 double predict_region_elapsed_time_ms(HeapRegion* hr, bool young); | |
| 480 | |
| 481 // for use by: calculate_optimal_so_length(length) | |
| 482 void predict_gc_eff(size_t young_region_num, | |
| 483 size_t so_length, | |
| 484 double base_time_ms, | |
| 485 double *gc_eff, | |
| 486 double *pause_time_ms); | |
| 487 | |
| 488 // for use by: calculate_young_list_target_config(rs_length) | |
| 489 bool predict_gc_eff(size_t young_region_num, | |
| 490 size_t so_length, | |
| 491 double base_time_with_so_ms, | |
| 492 size_t init_free_regions, | |
| 493 double target_pause_time_ms, | |
| 494 double* gc_eff); | |
| 495 | |
| 496 void start_recording_regions(); | |
| 497 void record_cset_region(HeapRegion* hr, bool young); | |
| 498 void record_scan_only_regions(size_t scan_only_length); | |
| 499 void end_recording_regions(); | |
| 500 | |
| 501 void record_vtime_diff_ms(double vtime_diff_ms) { | |
| 502 _vtime_diff_ms = vtime_diff_ms; | |
| 503 } | |
| 504 | |
| 505 void record_young_free_cset_time_ms(double time_ms) { | |
| 506 _recorded_young_free_cset_time_ms = time_ms; | |
| 507 } | |
| 508 | |
| 509 void record_non_young_free_cset_time_ms(double time_ms) { | |
| 510 _recorded_non_young_free_cset_time_ms = time_ms; | |
| 511 } | |
| 512 | |
| 513 double predict_young_gc_eff() { | |
| 514 return get_new_neg_prediction(_young_gc_eff_seq); | |
| 515 } | |
| 516 | |
| 545 | 517 double predict_survivor_regions_evac_time(); |
| 518 | |
| 342 | 519 // </NEW PREDICTION> |
| 520 | |
| 521 public: | |
| 522 void cset_regions_freed() { | |
| 523 bool propagate = _last_young_gc_full && !_in_marking_window; | |
| 524 _short_lived_surv_rate_group->all_surviving_words_recorded(propagate); | |
| 525 _survivor_surv_rate_group->all_surviving_words_recorded(propagate); | |
| 526 // also call it on any more surv rate groups | |
| 527 } | |
| 528 | |
| 529 void set_known_garbage_bytes(size_t known_garbage_bytes) { | |
| 530 _known_garbage_bytes = known_garbage_bytes; | |
| 531 size_t heap_bytes = _g1->capacity(); | |
| 532 _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes; | |
| 533 } | |
| 534 | |
| 535 void decrease_known_garbage_bytes(size_t known_garbage_bytes) { | |
| 536 guarantee( _known_garbage_bytes >= known_garbage_bytes, "invariant" ); | |
| 537 | |
| 538 _known_garbage_bytes -= known_garbage_bytes; | |
| 539 size_t heap_bytes = _g1->capacity(); | |
| 540 _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes; | |
| 541 } | |
| 542 | |
| 543 G1MMUTracker* mmu_tracker() { | |
| 544 return _mmu_tracker; | |
| 545 } | |
| 546 | |
| 547 double predict_init_time_ms() { | |
| 548 return get_new_prediction(_concurrent_mark_init_times_ms); | |
| 549 } | |
| 550 | |
| 551 double predict_remark_time_ms() { | |
| 552 return get_new_prediction(_concurrent_mark_remark_times_ms); | |
| 553 } | |
| 554 | |
| 555 double predict_cleanup_time_ms() { | |
| 556 return get_new_prediction(_concurrent_mark_cleanup_times_ms); | |
| 557 } | |
| 558 | |
| 559 // Returns an estimate of the survival rate of the region at yg-age | |
| 560 // "yg_age". | |
| 545 | 561 double predict_yg_surv_rate(int age, SurvRateGroup* surv_rate_group) { |
| 562 TruncatedSeq* seq = surv_rate_group->get_seq(age); | |
| 342 | 563 if (seq->num() == 0) |
| 564 gclog_or_tty->print("BARF! age is %d", age); | |
| 565 guarantee( seq->num() > 0, "invariant" ); | |
| 566 double pred = get_new_prediction(seq); | |
| 567 if (pred > 1.0) | |
| 568 pred = 1.0; | |
| 569 return pred; | |
| 570 } | |
| 571 | |
| 545 | 572 double predict_yg_surv_rate(int age) { |
| 573 return predict_yg_surv_rate(age, _short_lived_surv_rate_group); | |
| 574 } | |
| 575 | |
| 342 | 576 double accum_yg_surv_rate_pred(int age) { |
| 577 return _short_lived_surv_rate_group->accum_surv_rate_pred(age); | |
| 578 } | |
| 579 | |
| 580 protected: | |
| 581 void print_stats (int level, const char* str, double value); | |
| 582 void print_stats (int level, const char* str, int value); | |
| 583 void print_par_stats (int level, const char* str, double* data) { | |
| 584 print_par_stats(level, str, data, true); | |
| 585 } | |
| 586 void print_par_stats (int level, const char* str, double* data, bool summary); | |
| 587 void print_par_buffers (int level, const char* str, double* data, bool summary); | |
| 588 | |
| 589 void check_other_times(int level, | |
| 590 NumberSeq* other_times_ms, | |
| 591 NumberSeq* calc_other_times_ms) const; | |
| 592 | |
| 593 void print_summary (PauseSummary* stats) const; | |
| 677 | 594 void print_abandoned_summary(PauseSummary* summary) const; |
| 342 | 595 |
| 596 void print_summary (int level, const char* str, NumberSeq* seq) const; | |
| 597 void print_summary_sd (int level, const char* str, NumberSeq* seq) const; | |
| 598 | |
| 599 double avg_value (double* data); | |
| 600 double max_value (double* data); | |
| 601 double sum_of_values (double* data); | |
| 602 double max_sum (double* data1, double* data2); | |
| 603 | |
| 604 int _last_satb_drain_processed_buffers; | |
| 605 int _last_update_rs_processed_buffers; | |
| 606 double _last_pause_time_ms; | |
| 607 | |
| 608 size_t _bytes_in_to_space_before_gc; | |
| 609 size_t _bytes_in_to_space_after_gc; | |
| 610 size_t bytes_in_to_space_during_gc() { | |
| 611 return | |
| 612 _bytes_in_to_space_after_gc - _bytes_in_to_space_before_gc; | |
| 613 } | |
| 614 size_t _bytes_in_collection_set_before_gc; | |
| 615 // Used to count used bytes in CS. | |
| 616 friend class CountCSClosure; | |
| 617 | |
| 618 // Statistics kept per GC stoppage, pause or full. | |
| 619 TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec; | |
| 620 | |
| 621 // We track markings. | |
| 622 int _num_markings; | |
| 623 double _mark_thread_startup_sec; // Time at startup of marking thread | |
| 624 | |
| 625 // Add a new GC of the given duration and end time to the record. | |
| 626 void update_recent_gc_times(double end_time_sec, double elapsed_ms); | |
| 627 | |
| 628 // The head of the list (via "next_in_collection_set()") representing the | |
| 629 // current collection set. | |
| 630 HeapRegion* _collection_set; | |
| 631 size_t _collection_set_size; | |
| 632 size_t _collection_set_bytes_used_before; | |
| 633 | |
| 634 // Info about marking. | |
| 635 int _n_marks; // Sticky at 2, so we know when we've done at least 2. | |
| 636 | |
| 637 // The number of collection pauses at the end of the last mark. | |
| 638 size_t _n_pauses_at_mark_end; | |
| 639 | |
| 640 // ==== This section is for stats related to starting Conc Refinement on time. | |
| 641 size_t _conc_refine_enabled; | |
| 642 size_t _conc_refine_zero_traversals; | |
| 643 size_t _conc_refine_max_traversals; | |
| 644 // In # of heap regions. | |
| 645 size_t _conc_refine_current_delta; | |
| 646 | |
| 647 // At the beginning of a collection pause, update the variables above, | |
| 648 // especially the "delta". | |
| 649 void update_conc_refine_data(); | |
| 650 // ==== | |
| 651 | |
| 652 // Stash a pointer to the g1 heap. | |
| 653 G1CollectedHeap* _g1; | |
| 654 | |
| 655 // The average time in ms per collection pause, averaged over recent pauses. | |
| 656 double recent_avg_time_for_pauses_ms(); | |
| 657 | |
| 658 // The average time in ms for processing CollectedHeap strong roots, per | |
| 659 // collection pause, averaged over recent pauses. | |
| 660 double recent_avg_time_for_CH_strong_ms(); | |
| 661 | |
| 662 // The average time in ms for processing the G1 remembered set, per | |
| 663 // pause, averaged over recent pauses. | |
| 664 double recent_avg_time_for_G1_strong_ms(); | |
| 665 | |
| 666 // The average time in ms for "evacuating followers", per pause, averaged | |
| 667 // over recent pauses. | |
| 668 double recent_avg_time_for_evac_ms(); | |
| 669 | |
| 670 // The number of "recent" GCs recorded in the number sequences | |
| 671 int number_of_recent_gcs(); | |
| 672 | |
| 673 // The average survival ratio, computed by the total number of bytes | |
| 674 // suriviving / total number of bytes before collection over the last | |
| 675 // several recent pauses. | |
| 676 double recent_avg_survival_fraction(); | |
| 677 // The survival fraction of the most recent pause; if there have been no | |
| 678 // pauses, returns 1.0. | |
| 679 double last_survival_fraction(); | |
| 680 | |
| 681 // Returns a "conservative" estimate of the recent survival rate, i.e., | |
| 682 // one that may be higher than "recent_avg_survival_fraction". | |
| 683 // This is conservative in several ways: | |
| 684 // If there have been few pauses, it will assume a potential high | |
| 685 // variance, and err on the side of caution. | |
| 686 // It puts a lower bound (currently 0.1) on the value it will return. | |
| 687 // To try to detect phase changes, if the most recent pause ("latest") has a | |
| 688 // higher-than average ("avg") survival rate, it returns that rate. | |
| 689 // "work" version is a utility function; young is restricted to young regions. | |
| 690 double conservative_avg_survival_fraction_work(double avg, | |
| 691 double latest); | |
| 692 | |
| 693 // The arguments are the two sequences that keep track of the number of bytes | |
| 694 // surviving and the total number of bytes before collection, resp., | |
| 695 // over the last evereal recent pauses | |
| 696 // Returns the survival rate for the category in the most recent pause. | |
| 697 // If there have been no pauses, returns 1.0. | |
| 698 double last_survival_fraction_work(TruncatedSeq* surviving, | |
| 699 TruncatedSeq* before); | |
| 700 | |
| 701 // The arguments are the two sequences that keep track of the number of bytes | |
| 702 // surviving and the total number of bytes before collection, resp., | |
| 703 // over the last several recent pauses | |
| 704 // Returns the average survival ration over the last several recent pauses | |
| 705 // If there have been no pauses, return 1.0 | |
| 706 double recent_avg_survival_fraction_work(TruncatedSeq* surviving, | |
| 707 TruncatedSeq* before); | |
| 708 | |
| 709 double conservative_avg_survival_fraction() { | |
| 710 double avg = recent_avg_survival_fraction(); | |
| 711 double latest = last_survival_fraction(); | |
| 712 return conservative_avg_survival_fraction_work(avg, latest); | |
| 713 } | |
| 714 | |
| 715 // The ratio of gc time to elapsed time, computed over recent pauses. | |
| 716 double _recent_avg_pause_time_ratio; | |
| 717 | |
| 718 double recent_avg_pause_time_ratio() { | |
| 719 return _recent_avg_pause_time_ratio; | |
| 720 } | |
| 721 | |
| 722 // Number of pauses between concurrent marking. | |
| 723 size_t _pauses_btwn_concurrent_mark; | |
| 724 | |
| 725 size_t _n_marks_since_last_pause; | |
| 726 | |
| 727 // True iff CM has been initiated. | |
| 728 bool _conc_mark_initiated; | |
| 729 | |
| 730 // True iff CM should be initiated | |
| 731 bool _should_initiate_conc_mark; | |
| 732 bool _should_revert_to_full_young_gcs; | |
| 733 bool _last_full_young_gc; | |
| 734 | |
| 735 // This set of variables tracks the collector efficiency, in order to | |
| 736 // determine whether we should initiate a new marking. | |
| 737 double _cur_mark_stop_world_time_ms; | |
| 738 double _mark_init_start_sec; | |
| 739 double _mark_remark_start_sec; | |
| 740 double _mark_cleanup_start_sec; | |
| 741 double _mark_closure_time_ms; | |
| 742 | |
| 743 void calculate_young_list_min_length(); | |
| 744 void calculate_young_list_target_config(); | |
| 745 void calculate_young_list_target_config(size_t rs_lengths); | |
| 746 size_t calculate_optimal_so_length(size_t young_list_length); | |
| 747 | |
| 748 public: | |
| 749 | |
| 750 G1CollectorPolicy(); | |
| 751 | |
| 752 virtual G1CollectorPolicy* as_g1_policy() { return this; } | |
| 753 | |
| 754 virtual CollectorPolicy::Name kind() { | |
| 755 return CollectorPolicy::G1CollectorPolicyKind; | |
| 756 } | |
| 757 | |
| 758 void check_prediction_validity(); | |
| 759 | |
| 760 size_t bytes_in_collection_set() { | |
| 761 return _bytes_in_collection_set_before_gc; | |
| 762 } | |
| 763 | |
| 764 size_t bytes_in_to_space() { | |
| 765 return bytes_in_to_space_during_gc(); | |
| 766 } | |
| 767 | |
| 768 unsigned calc_gc_alloc_time_stamp() { | |
| 769 return _all_pause_times_ms->num() + 1; | |
| 770 } | |
| 771 | |
| 772 protected: | |
| 773 | |
| 774 // Count the number of bytes used in the CS. | |
| 775 void count_CS_bytes_used(); | |
| 776 | |
| 777 // Together these do the base cleanup-recording work. Subclasses might | |
| 778 // want to put something between them. | |
| 779 void record_concurrent_mark_cleanup_end_work1(size_t freed_bytes, | |
| 780 size_t max_live_bytes); | |
| 781 void record_concurrent_mark_cleanup_end_work2(); | |
| 782 | |
| 783 public: | |
| 784 | |
| 785 virtual void init(); | |
| 786 | |
| 545 | 787 // Create jstat counters for the policy. |
| 788 virtual void initialize_gc_policy_counters(); | |
| 789 | |
| 342 | 790 virtual HeapWord* mem_allocate_work(size_t size, |
| 791 bool is_tlab, | |
| 792 bool* gc_overhead_limit_was_exceeded); | |
| 793 | |
| 794 // This method controls how a collector handles one or more | |
| 795 // of its generations being fully allocated. | |
| 796 virtual HeapWord* satisfy_failed_allocation(size_t size, | |
| 797 bool is_tlab); | |
| 798 | |
| 799 BarrierSet::Name barrier_set_name() { return BarrierSet::G1SATBCTLogging; } | |
| 800 | |
| 801 GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; } | |
| 802 | |
| 803 // The number of collection pauses so far. | |
| 804 long n_pauses() const { return _n_pauses; } | |
| 805 | |
| 806 // Update the heuristic info to record a collection pause of the given | |
| 807 // start time, where the given number of bytes were used at the start. | |
| 808 // This may involve changing the desired size of a collection set. | |
| 809 | |
| 810 virtual void record_stop_world_start(); | |
| 811 | |
| 812 virtual void record_collection_pause_start(double start_time_sec, | |
| 813 size_t start_used); | |
| 814 | |
| 815 // Must currently be called while the world is stopped. | |
| 816 virtual void record_concurrent_mark_init_start(); | |
| 817 virtual void record_concurrent_mark_init_end(); | |
| 818 void record_concurrent_mark_init_end_pre(double | |
| 819 mark_init_elapsed_time_ms); | |
| 820 | |
| 821 void record_mark_closure_time(double mark_closure_time_ms); | |
| 822 | |
| 823 virtual void record_concurrent_mark_remark_start(); | |
| 824 virtual void record_concurrent_mark_remark_end(); | |
| 825 | |
| 826 virtual void record_concurrent_mark_cleanup_start(); | |
| 827 virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes, | |
| 828 size_t max_live_bytes); | |
| 829 virtual void record_concurrent_mark_cleanup_completed(); | |
| 830 | |
| 831 virtual void record_concurrent_pause(); | |
| 832 virtual void record_concurrent_pause_end(); | |
| 833 | |
| 834 virtual void record_collection_pause_end_CH_strong_roots(); | |
| 835 virtual void record_collection_pause_end_G1_strong_roots(); | |
| 836 | |
| 677 | 837 virtual void record_collection_pause_end(bool abandoned); |
| 342 | 838 |
| 839 // Record the fact that a full collection occurred. | |
| 840 virtual void record_full_collection_start(); | |
| 841 virtual void record_full_collection_end(); | |
| 842 | |
| 843 void record_ext_root_scan_time(int worker_i, double ms) { | |
| 844 _par_last_ext_root_scan_times_ms[worker_i] = ms; | |
| 845 } | |
| 846 | |
| 847 void record_mark_stack_scan_time(int worker_i, double ms) { | |
| 848 _par_last_mark_stack_scan_times_ms[worker_i] = ms; | |
| 849 } | |
| 850 | |
| 851 void record_scan_only_time(int worker_i, double ms, int n) { | |
| 852 _par_last_scan_only_times_ms[worker_i] = ms; | |
| 853 _par_last_scan_only_regions_scanned[worker_i] = (double) n; | |
| 854 } | |
| 855 | |
| 856 void record_satb_drain_time(double ms) { | |
| 857 _cur_satb_drain_time_ms = ms; | |
| 858 _satb_drain_time_set = true; | |
| 859 } | |
| 860 | |
| 861 void record_satb_drain_processed_buffers (int processed_buffers) { | |
| 862 _last_satb_drain_processed_buffers = processed_buffers; | |
| 863 } | |
| 864 | |
| 865 void record_mod_union_time(double ms) { | |
| 866 _all_mod_union_times_ms->add(ms); | |
| 867 } | |
| 868 | |
| 869 void record_update_rs_start_time(int thread, double ms) { | |
| 870 _par_last_update_rs_start_times_ms[thread] = ms; | |
| 871 } | |
| 872 | |
| 873 void record_update_rs_time(int thread, double ms) { | |
| 874 _par_last_update_rs_times_ms[thread] = ms; | |
| 875 } | |
| 876 | |
| 877 void record_update_rs_processed_buffers (int thread, | |
| 878 double processed_buffers) { | |
| 879 _par_last_update_rs_processed_buffers[thread] = processed_buffers; | |
| 880 } | |
| 881 | |
| 882 void record_scan_rs_start_time(int thread, double ms) { | |
| 883 _par_last_scan_rs_start_times_ms[thread] = ms; | |
| 884 } | |
| 885 | |
| 886 void record_scan_rs_time(int thread, double ms) { | |
| 887 _par_last_scan_rs_times_ms[thread] = ms; | |
| 888 } | |
| 889 | |
| 890 void record_scan_new_refs_time(int thread, double ms) { | |
| 891 _par_last_scan_new_refs_times_ms[thread] = ms; | |
| 892 } | |
| 893 | |
| 894 double get_scan_new_refs_time(int thread) { | |
| 895 return _par_last_scan_new_refs_times_ms[thread]; | |
| 896 } | |
| 897 | |
| 898 void reset_obj_copy_time(int thread) { | |
| 899 _par_last_obj_copy_times_ms[thread] = 0.0; | |
| 900 } | |
| 901 | |
| 902 void reset_obj_copy_time() { | |
| 903 reset_obj_copy_time(0); | |
| 904 } | |
| 905 | |
| 906 void record_obj_copy_time(int thread, double ms) { | |
| 907 _par_last_obj_copy_times_ms[thread] += ms; | |
| 908 } | |
| 909 | |
| 910 void record_obj_copy_time(double ms) { | |
| 911 record_obj_copy_time(0, ms); | |
| 912 } | |
| 913 | |
| 914 void record_termination_time(int thread, double ms) { | |
| 915 _par_last_termination_times_ms[thread] = ms; | |
| 916 } | |
| 917 | |
| 918 void record_termination_time(double ms) { | |
| 919 record_termination_time(0, ms); | |
| 920 } | |
| 921 | |
|
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|
922 void record_pause_time_ms(double ms) { |
| 342 | 923 _last_pause_time_ms = ms; |
| 924 } | |
| 925 | |
| 926 void record_clear_ct_time(double ms) { | |
| 927 _cur_clear_ct_time_ms = ms; | |
| 928 } | |
| 929 | |
| 930 void record_par_time(double ms) { | |
| 931 _cur_collection_par_time_ms = ms; | |
| 932 } | |
| 933 | |
| 934 void record_aux_start_time(int i) { | |
| 935 guarantee(i < _aux_num, "should be within range"); | |
| 936 _cur_aux_start_times_ms[i] = os::elapsedTime() * 1000.0; | |
| 937 } | |
| 938 | |
| 939 void record_aux_end_time(int i) { | |
| 940 guarantee(i < _aux_num, "should be within range"); | |
| 941 double ms = os::elapsedTime() * 1000.0 - _cur_aux_start_times_ms[i]; | |
| 942 _cur_aux_times_set[i] = true; | |
| 943 _cur_aux_times_ms[i] += ms; | |
| 944 } | |
| 945 | |
| 946 // Record the fact that "bytes" bytes allocated in a region. | |
| 947 void record_before_bytes(size_t bytes); | |
| 948 void record_after_bytes(size_t bytes); | |
| 949 | |
| 950 // Returns "true" if this is a good time to do a collection pause. | |
| 951 // The "word_size" argument, if non-zero, indicates the size of an | |
| 952 // allocation request that is prompting this query. | |
| 953 virtual bool should_do_collection_pause(size_t word_size) = 0; | |
| 954 | |
| 955 // Choose a new collection set. Marks the chosen regions as being | |
| 956 // "in_collection_set", and links them together. The head and number of | |
| 957 // the collection set are available via access methods. | |
| 677 | 958 virtual void choose_collection_set() = 0; |
| 342 | 959 |
| 960 void clear_collection_set() { _collection_set = NULL; } | |
| 961 | |
| 962 // The head of the list (via "next_in_collection_set()") representing the | |
| 963 // current collection set. | |
| 964 HeapRegion* collection_set() { return _collection_set; } | |
| 965 | |
| 966 // The number of elements in the current collection set. | |
| 967 size_t collection_set_size() { return _collection_set_size; } | |
| 968 | |
| 969 // Add "hr" to the CS. | |
| 970 void add_to_collection_set(HeapRegion* hr); | |
| 971 | |
| 972 bool should_initiate_conc_mark() { return _should_initiate_conc_mark; } | |
| 973 void set_should_initiate_conc_mark() { _should_initiate_conc_mark = true; } | |
| 974 void unset_should_initiate_conc_mark(){ _should_initiate_conc_mark = false; } | |
| 975 | |
| 976 void checkpoint_conc_overhead(); | |
| 977 | |
| 978 // If an expansion would be appropriate, because recent GC overhead had | |
| 979 // exceeded the desired limit, return an amount to expand by. | |
| 980 virtual size_t expansion_amount(); | |
| 981 | |
| 982 // note start of mark thread | |
| 983 void note_start_of_mark_thread(); | |
| 984 | |
| 985 // The marked bytes of the "r" has changed; reclassify it's desirability | |
| 986 // for marking. Also asserts that "r" is eligible for a CS. | |
| 987 virtual void note_change_in_marked_bytes(HeapRegion* r) = 0; | |
| 988 | |
| 989 #ifndef PRODUCT | |
| 990 // Check any appropriate marked bytes info, asserting false if | |
| 991 // something's wrong, else returning "true". | |
| 992 virtual bool assertMarkedBytesDataOK() = 0; | |
| 993 #endif | |
| 994 | |
| 995 // Print tracing information. | |
| 996 void print_tracing_info() const; | |
| 997 | |
| 998 // Print stats on young survival ratio | |
| 999 void print_yg_surv_rate_info() const; | |
| 1000 | |
| 545 | 1001 void finished_recalculating_age_indexes(bool is_survivors) { |
| 1002 if (is_survivors) { | |
| 1003 _survivor_surv_rate_group->finished_recalculating_age_indexes(); | |
| 1004 } else { | |
| 1005 _short_lived_surv_rate_group->finished_recalculating_age_indexes(); | |
| 1006 } | |
| 342 | 1007 // do that for any other surv rate groups |
| 1008 } | |
| 1009 | |
| 1010 bool should_add_next_region_to_young_list(); | |
| 1011 | |
| 1012 bool in_young_gc_mode() { | |
| 1013 return _in_young_gc_mode; | |
| 1014 } | |
| 1015 void set_in_young_gc_mode(bool in_young_gc_mode) { | |
| 1016 _in_young_gc_mode = in_young_gc_mode; | |
| 1017 } | |
| 1018 | |
| 1019 bool full_young_gcs() { | |
| 1020 return _full_young_gcs; | |
| 1021 } | |
| 1022 void set_full_young_gcs(bool full_young_gcs) { | |
| 1023 _full_young_gcs = full_young_gcs; | |
| 1024 } | |
| 1025 | |
| 1026 bool adaptive_young_list_length() { | |
| 1027 return _adaptive_young_list_length; | |
| 1028 } | |
| 1029 void set_adaptive_young_list_length(bool adaptive_young_list_length) { | |
| 1030 _adaptive_young_list_length = adaptive_young_list_length; | |
| 1031 } | |
| 1032 | |
| 1033 inline double get_gc_eff_factor() { | |
| 1034 double ratio = _known_garbage_ratio; | |
| 1035 | |
| 1036 double square = ratio * ratio; | |
| 1037 // square = square * square; | |
| 1038 double ret = square * 9.0 + 1.0; | |
| 1039 #if 0 | |
| 1040 gclog_or_tty->print_cr("ratio = %1.2lf, ret = %1.2lf", ratio, ret); | |
| 1041 #endif // 0 | |
| 1042 guarantee(0.0 <= ret && ret < 10.0, "invariant!"); | |
| 1043 return ret; | |
| 1044 } | |
| 1045 | |
| 1046 // | |
| 1047 // Survivor regions policy. | |
| 1048 // | |
| 1049 protected: | |
| 1050 | |
| 1051 // Current tenuring threshold, set to 0 if the collector reaches the | |
| 1052 // maximum amount of suvivors regions. | |
| 1053 int _tenuring_threshold; | |
| 1054 | |
| 545 | 1055 // The limit on the number of regions allocated for survivors. |
| 1056 size_t _max_survivor_regions; | |
| 1057 | |
| 1058 // The amount of survor regions after a collection. | |
| 1059 size_t _recorded_survivor_regions; | |
| 1060 // List of survivor regions. | |
| 1061 HeapRegion* _recorded_survivor_head; | |
| 1062 HeapRegion* _recorded_survivor_tail; | |
| 1063 | |
| 1064 ageTable _survivors_age_table; | |
| 1065 | |
| 342 | 1066 public: |
| 1067 | |
| 1068 inline GCAllocPurpose | |
| 1069 evacuation_destination(HeapRegion* src_region, int age, size_t word_sz) { | |
| 1070 if (age < _tenuring_threshold && src_region->is_young()) { | |
| 1071 return GCAllocForSurvived; | |
| 1072 } else { | |
| 1073 return GCAllocForTenured; | |
| 1074 } | |
| 1075 } | |
| 1076 | |
| 1077 inline bool track_object_age(GCAllocPurpose purpose) { | |
| 1078 return purpose == GCAllocForSurvived; | |
| 1079 } | |
| 1080 | |
| 1081 inline GCAllocPurpose alternative_purpose(int purpose) { | |
| 1082 return GCAllocForTenured; | |
| 1083 } | |
| 1084 | |
| 545 | 1085 static const size_t REGIONS_UNLIMITED = ~(size_t)0; |
| 1086 | |
| 1087 size_t max_regions(int purpose); | |
| 342 | 1088 |
| 1089 // The limit on regions for a particular purpose is reached. | |
| 1090 void note_alloc_region_limit_reached(int purpose) { | |
| 1091 if (purpose == GCAllocForSurvived) { | |
| 1092 _tenuring_threshold = 0; | |
| 1093 } | |
| 1094 } | |
| 1095 | |
| 1096 void note_start_adding_survivor_regions() { | |
| 1097 _survivor_surv_rate_group->start_adding_regions(); | |
| 1098 } | |
| 1099 | |
| 1100 void note_stop_adding_survivor_regions() { | |
| 1101 _survivor_surv_rate_group->stop_adding_regions(); | |
| 1102 } | |
| 545 | 1103 |
| 1104 void record_survivor_regions(size_t regions, | |
| 1105 HeapRegion* head, | |
| 1106 HeapRegion* tail) { | |
| 1107 _recorded_survivor_regions = regions; | |
| 1108 _recorded_survivor_head = head; | |
| 1109 _recorded_survivor_tail = tail; | |
| 1110 } | |
| 1111 | |
| 1112 void record_thread_age_table(ageTable* age_table) | |
| 1113 { | |
| 1114 _survivors_age_table.merge_par(age_table); | |
| 1115 } | |
| 1116 | |
| 1117 // Calculates survivor space parameters. | |
| 1118 void calculate_survivors_policy(); | |
| 1119 | |
| 342 | 1120 }; |
| 1121 | |
| 1122 // This encapsulates a particular strategy for a g1 Collector. | |
| 1123 // | |
| 1124 // Start a concurrent mark when our heap size is n bytes | |
| 1125 // greater then our heap size was at the last concurrent | |
| 1126 // mark. Where n is a function of the CMSTriggerRatio | |
| 1127 // and the MinHeapFreeRatio. | |
| 1128 // | |
| 1129 // Start a g1 collection pause when we have allocated the | |
| 1130 // average number of bytes currently being freed in | |
| 1131 // a collection, but only if it is at least one region | |
| 1132 // full | |
| 1133 // | |
| 1134 // Resize Heap based on desired | |
| 1135 // allocation space, where desired allocation space is | |
| 1136 // a function of survival rate and desired future to size. | |
| 1137 // | |
| 1138 // Choose collection set by first picking all older regions | |
| 1139 // which have a survival rate which beats our projected young | |
| 1140 // survival rate. Then fill out the number of needed regions | |
| 1141 // with young regions. | |
| 1142 | |
| 1143 class G1CollectorPolicy_BestRegionsFirst: public G1CollectorPolicy { | |
| 1144 CollectionSetChooser* _collectionSetChooser; | |
| 1145 // If the estimated is less then desirable, resize if possible. | |
| 1146 void expand_if_possible(size_t numRegions); | |
| 1147 | |
| 677 | 1148 virtual void choose_collection_set(); |
| 342 | 1149 virtual void record_collection_pause_start(double start_time_sec, |
| 1150 size_t start_used); | |
| 1151 virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes, | |
| 1152 size_t max_live_bytes); | |
| 1153 virtual void record_full_collection_end(); | |
| 1154 | |
| 1155 public: | |
| 1156 G1CollectorPolicy_BestRegionsFirst() { | |
| 1157 _collectionSetChooser = new CollectionSetChooser(); | |
| 1158 } | |
| 677 | 1159 void record_collection_pause_end(bool abandoned); |
| 342 | 1160 bool should_do_collection_pause(size_t word_size); |
| 1161 // This is not needed any more, after the CSet choosing code was | |
| 1162 // changed to use the pause prediction work. But let's leave the | |
| 1163 // hook in just in case. | |
| 1164 void note_change_in_marked_bytes(HeapRegion* r) { } | |
| 1165 #ifndef PRODUCT | |
| 1166 bool assertMarkedBytesDataOK(); | |
| 1167 #endif | |
| 1168 }; | |
| 1169 | |
| 1170 // This should move to some place more general... | |
| 1171 | |
| 1172 // If we have "n" measurements, and we've kept track of their "sum" and the | |
| 1173 // "sum_of_squares" of the measurements, this returns the variance of the | |
| 1174 // sequence. | |
| 1175 inline double variance(int n, double sum_of_squares, double sum) { | |
| 1176 double n_d = (double)n; | |
| 1177 double avg = sum/n_d; | |
| 1178 return (sum_of_squares - 2.0 * avg * sum + n_d * avg * avg) / n_d; | |
| 1179 } | |
| 1180 | |
| 1181 // Local Variables: *** | |
| 1182 // c-indentation-style: gnu *** | |
| 1183 // End: *** |