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rev 2691 : [mq]: g1-reference-processing
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--- old/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp
+++ new/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp
1 1 /*
2 2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
3 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 4 *
5 5 * This code is free software; you can redistribute it and/or modify it
6 6 * under the terms of the GNU General Public License version 2 only, as
7 7 * published by the Free Software Foundation.
8 8 *
9 9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 12 * version 2 for more details (a copy is included in the LICENSE file that
13 13 * accompanied this code).
14 14 *
15 15 * You should have received a copy of the GNU General Public License version
16 16 * 2 along with this work; if not, write to the Free Software Foundation,
17 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 18 *
19 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 20 * or visit www.oracle.com if you need additional information or have any
21 21 * questions.
22 22 *
23 23 */
24 24
25 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP
26 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP
27 27
28 28 #include "gc_implementation/g1/collectionSetChooser.hpp"
29 29 #include "gc_implementation/g1/g1MMUTracker.hpp"
30 30 #include "memory/collectorPolicy.hpp"
31 31
32 32 // A G1CollectorPolicy makes policy decisions that determine the
33 33 // characteristics of the collector. Examples include:
34 34 // * choice of collection set.
35 35 // * when to collect.
36 36
37 37 class HeapRegion;
38 38 class CollectionSetChooser;
39 39
40 40 // Yes, this is a bit unpleasant... but it saves replicating the same thing
41 41 // over and over again and introducing subtle problems through small typos and
42 42 // cutting and pasting mistakes. The macros below introduces a number
43 43 // sequnce into the following two classes and the methods that access it.
44 44
45 45 #define define_num_seq(name) \
46 46 private: \
47 47 NumberSeq _all_##name##_times_ms; \
48 48 public: \
49 49 void record_##name##_time_ms(double ms) { \
50 50 _all_##name##_times_ms.add(ms); \
51 51 } \
52 52 NumberSeq* get_##name##_seq() { \
53 53 return &_all_##name##_times_ms; \
54 54 }
55 55
56 56 class MainBodySummary;
57 57
58 58 class PauseSummary: public CHeapObj {
59 59 define_num_seq(total)
60 60 define_num_seq(other)
61 61
62 62 public:
63 63 virtual MainBodySummary* main_body_summary() { return NULL; }
64 64 };
65 65
66 66 class MainBodySummary: public CHeapObj {
67 67 define_num_seq(satb_drain) // optional
68 68 define_num_seq(parallel) // parallel only
69 69 define_num_seq(ext_root_scan)
70 70 define_num_seq(mark_stack_scan)
71 71 define_num_seq(update_rs)
72 72 define_num_seq(scan_rs)
73 73 define_num_seq(obj_copy)
74 74 define_num_seq(termination) // parallel only
75 75 define_num_seq(parallel_other) // parallel only
76 76 define_num_seq(mark_closure)
77 77 define_num_seq(clear_ct) // parallel only
78 78 };
79 79
80 80 class Summary: public PauseSummary,
81 81 public MainBodySummary {
82 82 public:
83 83 virtual MainBodySummary* main_body_summary() { return this; }
84 84 };
85 85
86 86 class G1CollectorPolicy: public CollectorPolicy {
87 87 protected:
88 88 // The number of pauses during the execution.
89 89 long _n_pauses;
90 90
91 91 // either equal to the number of parallel threads, if ParallelGCThreads
92 92 // has been set, or 1 otherwise
93 93 int _parallel_gc_threads;
94 94
95 95 enum SomePrivateConstants {
96 96 NumPrevPausesForHeuristics = 10
97 97 };
98 98
99 99 G1MMUTracker* _mmu_tracker;
100 100
101 101 void initialize_flags();
102 102
103 103 void initialize_all() {
104 104 initialize_flags();
105 105 initialize_size_info();
106 106 initialize_perm_generation(PermGen::MarkSweepCompact);
107 107 }
108 108
109 109 virtual size_t default_init_heap_size() {
110 110 // Pick some reasonable default.
111 111 return 8*M;
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112 112 }
113 113
114 114 double _cur_collection_start_sec;
115 115 size_t _cur_collection_pause_used_at_start_bytes;
116 116 size_t _cur_collection_pause_used_regions_at_start;
117 117 size_t _prev_collection_pause_used_at_end_bytes;
118 118 double _cur_collection_par_time_ms;
119 119 double _cur_satb_drain_time_ms;
120 120 double _cur_clear_ct_time_ms;
121 121 bool _satb_drain_time_set;
122 + double _cur_ref_proc_time_ms;
123 + double _cur_ref_enq_time_ms;
122 124
123 125 #ifndef PRODUCT
124 126 // Card Table Count Cache stats
125 127 double _min_clear_cc_time_ms; // min
126 128 double _max_clear_cc_time_ms; // max
127 129 double _cur_clear_cc_time_ms; // clearing time during current pause
128 130 double _cum_clear_cc_time_ms; // cummulative clearing time
129 131 jlong _num_cc_clears; // number of times the card count cache has been cleared
130 132 #endif
131 133
132 134 // Statistics for recent GC pauses. See below for how indexed.
133 135 TruncatedSeq* _recent_rs_scan_times_ms;
134 136
135 137 // These exclude marking times.
136 138 TruncatedSeq* _recent_pause_times_ms;
137 139 TruncatedSeq* _recent_gc_times_ms;
138 140
139 141 TruncatedSeq* _recent_CS_bytes_used_before;
140 142 TruncatedSeq* _recent_CS_bytes_surviving;
141 143
142 144 TruncatedSeq* _recent_rs_sizes;
143 145
144 146 TruncatedSeq* _concurrent_mark_remark_times_ms;
145 147 TruncatedSeq* _concurrent_mark_cleanup_times_ms;
146 148
147 149 Summary* _summary;
148 150
149 151 NumberSeq* _all_pause_times_ms;
150 152 NumberSeq* _all_full_gc_times_ms;
151 153 double _stop_world_start;
152 154 NumberSeq* _all_stop_world_times_ms;
153 155 NumberSeq* _all_yield_times_ms;
154 156
155 157 size_t _region_num_young;
156 158 size_t _region_num_tenured;
157 159 size_t _prev_region_num_young;
158 160 size_t _prev_region_num_tenured;
159 161
160 162 NumberSeq* _all_mod_union_times_ms;
161 163
162 164 int _aux_num;
163 165 NumberSeq* _all_aux_times_ms;
164 166 double* _cur_aux_start_times_ms;
165 167 double* _cur_aux_times_ms;
166 168 bool* _cur_aux_times_set;
167 169
168 170 double* _par_last_gc_worker_start_times_ms;
169 171 double* _par_last_ext_root_scan_times_ms;
170 172 double* _par_last_mark_stack_scan_times_ms;
171 173 double* _par_last_update_rs_times_ms;
172 174 double* _par_last_update_rs_processed_buffers;
173 175 double* _par_last_scan_rs_times_ms;
174 176 double* _par_last_obj_copy_times_ms;
175 177 double* _par_last_termination_times_ms;
176 178 double* _par_last_termination_attempts;
177 179 double* _par_last_gc_worker_end_times_ms;
178 180 double* _par_last_gc_worker_times_ms;
179 181
180 182 // indicates whether we are in full young or partially young GC mode
181 183 bool _full_young_gcs;
182 184
183 185 // if true, then it tries to dynamically adjust the length of the
184 186 // young list
185 187 bool _adaptive_young_list_length;
186 188 size_t _young_list_target_length;
187 189 size_t _young_list_fixed_length;
188 190 size_t _prev_eden_capacity; // used for logging
189 191
190 192 // The max number of regions we can extend the eden by while the GC
191 193 // locker is active. This should be >= _young_list_target_length;
192 194 size_t _young_list_max_length;
193 195
194 196 size_t _young_cset_length;
195 197 bool _last_young_gc_full;
196 198
197 199 unsigned _full_young_pause_num;
198 200 unsigned _partial_young_pause_num;
199 201
200 202 bool _during_marking;
201 203 bool _in_marking_window;
202 204 bool _in_marking_window_im;
203 205
204 206 SurvRateGroup* _short_lived_surv_rate_group;
205 207 SurvRateGroup* _survivor_surv_rate_group;
206 208 // add here any more surv rate groups
207 209
208 210 double _gc_overhead_perc;
209 211
210 212 double _reserve_factor;
211 213 size_t _reserve_regions;
212 214
213 215 bool during_marking() {
214 216 return _during_marking;
215 217 }
216 218
217 219 // <NEW PREDICTION>
218 220
219 221 private:
220 222 enum PredictionConstants {
221 223 TruncatedSeqLength = 10
222 224 };
223 225
224 226 TruncatedSeq* _alloc_rate_ms_seq;
225 227 double _prev_collection_pause_end_ms;
226 228
227 229 TruncatedSeq* _pending_card_diff_seq;
228 230 TruncatedSeq* _rs_length_diff_seq;
229 231 TruncatedSeq* _cost_per_card_ms_seq;
230 232 TruncatedSeq* _fully_young_cards_per_entry_ratio_seq;
231 233 TruncatedSeq* _partially_young_cards_per_entry_ratio_seq;
232 234 TruncatedSeq* _cost_per_entry_ms_seq;
233 235 TruncatedSeq* _partially_young_cost_per_entry_ms_seq;
234 236 TruncatedSeq* _cost_per_byte_ms_seq;
235 237 TruncatedSeq* _constant_other_time_ms_seq;
236 238 TruncatedSeq* _young_other_cost_per_region_ms_seq;
237 239 TruncatedSeq* _non_young_other_cost_per_region_ms_seq;
238 240
239 241 TruncatedSeq* _pending_cards_seq;
240 242 TruncatedSeq* _scanned_cards_seq;
241 243 TruncatedSeq* _rs_lengths_seq;
242 244
243 245 TruncatedSeq* _cost_per_byte_ms_during_cm_seq;
244 246
245 247 TruncatedSeq* _young_gc_eff_seq;
246 248
247 249 TruncatedSeq* _max_conc_overhead_seq;
248 250
249 251 bool _using_new_ratio_calculations;
250 252 size_t _min_desired_young_length; // as set on the command line or default calculations
251 253 size_t _max_desired_young_length; // as set on the command line or default calculations
252 254
253 255 size_t _recorded_young_regions;
254 256 size_t _recorded_non_young_regions;
255 257 size_t _recorded_region_num;
256 258
257 259 size_t _free_regions_at_end_of_collection;
258 260
259 261 size_t _recorded_rs_lengths;
260 262 size_t _max_rs_lengths;
261 263
262 264 size_t _recorded_marked_bytes;
263 265 size_t _recorded_young_bytes;
264 266
265 267 size_t _predicted_pending_cards;
266 268 size_t _predicted_cards_scanned;
267 269 size_t _predicted_rs_lengths;
268 270 size_t _predicted_bytes_to_copy;
269 271
270 272 double _predicted_survival_ratio;
271 273 double _predicted_rs_update_time_ms;
272 274 double _predicted_rs_scan_time_ms;
273 275 double _predicted_object_copy_time_ms;
274 276 double _predicted_constant_other_time_ms;
275 277 double _predicted_young_other_time_ms;
276 278 double _predicted_non_young_other_time_ms;
277 279 double _predicted_pause_time_ms;
278 280
279 281 double _vtime_diff_ms;
280 282
281 283 double _recorded_young_free_cset_time_ms;
282 284 double _recorded_non_young_free_cset_time_ms;
283 285
284 286 double _sigma;
285 287 double _expensive_region_limit_ms;
286 288
287 289 size_t _rs_lengths_prediction;
288 290
289 291 size_t _known_garbage_bytes;
290 292 double _known_garbage_ratio;
291 293
292 294 double sigma() {
293 295 return _sigma;
294 296 }
295 297
296 298 // A function that prevents us putting too much stock in small sample
297 299 // sets. Returns a number between 2.0 and 1.0, depending on the number
298 300 // of samples. 5 or more samples yields one; fewer scales linearly from
299 301 // 2.0 at 1 sample to 1.0 at 5.
300 302 double confidence_factor(int samples) {
301 303 if (samples > 4) return 1.0;
302 304 else return 1.0 + sigma() * ((double)(5 - samples))/2.0;
303 305 }
304 306
305 307 double get_new_neg_prediction(TruncatedSeq* seq) {
306 308 return seq->davg() - sigma() * seq->dsd();
307 309 }
308 310
309 311 #ifndef PRODUCT
310 312 bool verify_young_ages(HeapRegion* head, SurvRateGroup *surv_rate_group);
311 313 #endif // PRODUCT
312 314
313 315 void adjust_concurrent_refinement(double update_rs_time,
314 316 double update_rs_processed_buffers,
315 317 double goal_ms);
316 318
317 319 protected:
318 320 double _pause_time_target_ms;
319 321 double _recorded_young_cset_choice_time_ms;
320 322 double _recorded_non_young_cset_choice_time_ms;
321 323 bool _within_target;
322 324 size_t _pending_cards;
323 325 size_t _max_pending_cards;
324 326
325 327 public:
326 328
327 329 void set_region_short_lived(HeapRegion* hr) {
328 330 hr->install_surv_rate_group(_short_lived_surv_rate_group);
329 331 }
330 332
331 333 void set_region_survivors(HeapRegion* hr) {
332 334 hr->install_surv_rate_group(_survivor_surv_rate_group);
333 335 }
334 336
335 337 #ifndef PRODUCT
336 338 bool verify_young_ages();
337 339 #endif // PRODUCT
338 340
339 341 double get_new_prediction(TruncatedSeq* seq) {
340 342 return MAX2(seq->davg() + sigma() * seq->dsd(),
341 343 seq->davg() * confidence_factor(seq->num()));
342 344 }
343 345
344 346 size_t young_cset_length() {
345 347 return _young_cset_length;
346 348 }
347 349
348 350 void record_max_rs_lengths(size_t rs_lengths) {
349 351 _max_rs_lengths = rs_lengths;
350 352 }
351 353
352 354 size_t predict_pending_card_diff() {
353 355 double prediction = get_new_neg_prediction(_pending_card_diff_seq);
354 356 if (prediction < 0.00001)
355 357 return 0;
356 358 else
357 359 return (size_t) prediction;
358 360 }
359 361
360 362 size_t predict_pending_cards() {
361 363 size_t max_pending_card_num = _g1->max_pending_card_num();
362 364 size_t diff = predict_pending_card_diff();
363 365 size_t prediction;
364 366 if (diff > max_pending_card_num)
365 367 prediction = max_pending_card_num;
366 368 else
367 369 prediction = max_pending_card_num - diff;
368 370
369 371 return prediction;
370 372 }
371 373
372 374 size_t predict_rs_length_diff() {
373 375 return (size_t) get_new_prediction(_rs_length_diff_seq);
374 376 }
375 377
376 378 double predict_alloc_rate_ms() {
377 379 return get_new_prediction(_alloc_rate_ms_seq);
378 380 }
379 381
380 382 double predict_cost_per_card_ms() {
381 383 return get_new_prediction(_cost_per_card_ms_seq);
382 384 }
383 385
384 386 double predict_rs_update_time_ms(size_t pending_cards) {
385 387 return (double) pending_cards * predict_cost_per_card_ms();
386 388 }
387 389
388 390 double predict_fully_young_cards_per_entry_ratio() {
389 391 return get_new_prediction(_fully_young_cards_per_entry_ratio_seq);
390 392 }
391 393
392 394 double predict_partially_young_cards_per_entry_ratio() {
393 395 if (_partially_young_cards_per_entry_ratio_seq->num() < 2)
394 396 return predict_fully_young_cards_per_entry_ratio();
395 397 else
396 398 return get_new_prediction(_partially_young_cards_per_entry_ratio_seq);
397 399 }
398 400
399 401 size_t predict_young_card_num(size_t rs_length) {
400 402 return (size_t) ((double) rs_length *
401 403 predict_fully_young_cards_per_entry_ratio());
402 404 }
403 405
404 406 size_t predict_non_young_card_num(size_t rs_length) {
405 407 return (size_t) ((double) rs_length *
406 408 predict_partially_young_cards_per_entry_ratio());
407 409 }
408 410
409 411 double predict_rs_scan_time_ms(size_t card_num) {
410 412 if (full_young_gcs())
411 413 return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq);
412 414 else
413 415 return predict_partially_young_rs_scan_time_ms(card_num);
414 416 }
415 417
416 418 double predict_partially_young_rs_scan_time_ms(size_t card_num) {
417 419 if (_partially_young_cost_per_entry_ms_seq->num() < 3)
418 420 return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq);
419 421 else
420 422 return (double) card_num *
421 423 get_new_prediction(_partially_young_cost_per_entry_ms_seq);
422 424 }
423 425
424 426 double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) {
425 427 if (_cost_per_byte_ms_during_cm_seq->num() < 3)
426 428 return 1.1 * (double) bytes_to_copy *
427 429 get_new_prediction(_cost_per_byte_ms_seq);
428 430 else
429 431 return (double) bytes_to_copy *
430 432 get_new_prediction(_cost_per_byte_ms_during_cm_seq);
431 433 }
432 434
433 435 double predict_object_copy_time_ms(size_t bytes_to_copy) {
434 436 if (_in_marking_window && !_in_marking_window_im)
435 437 return predict_object_copy_time_ms_during_cm(bytes_to_copy);
436 438 else
437 439 return (double) bytes_to_copy *
438 440 get_new_prediction(_cost_per_byte_ms_seq);
439 441 }
440 442
441 443 double predict_constant_other_time_ms() {
442 444 return get_new_prediction(_constant_other_time_ms_seq);
443 445 }
444 446
445 447 double predict_young_other_time_ms(size_t young_num) {
446 448 return
447 449 (double) young_num *
448 450 get_new_prediction(_young_other_cost_per_region_ms_seq);
449 451 }
450 452
451 453 double predict_non_young_other_time_ms(size_t non_young_num) {
452 454 return
453 455 (double) non_young_num *
454 456 get_new_prediction(_non_young_other_cost_per_region_ms_seq);
455 457 }
456 458
457 459 void check_if_region_is_too_expensive(double predicted_time_ms);
458 460
459 461 double predict_young_collection_elapsed_time_ms(size_t adjustment);
460 462 double predict_base_elapsed_time_ms(size_t pending_cards);
461 463 double predict_base_elapsed_time_ms(size_t pending_cards,
462 464 size_t scanned_cards);
463 465 size_t predict_bytes_to_copy(HeapRegion* hr);
464 466 double predict_region_elapsed_time_ms(HeapRegion* hr, bool young);
465 467
466 468 void start_recording_regions();
467 469 void record_cset_region_info(HeapRegion* hr, bool young);
468 470 void record_non_young_cset_region(HeapRegion* hr);
469 471
470 472 void set_recorded_young_regions(size_t n_regions);
471 473 void set_recorded_young_bytes(size_t bytes);
472 474 void set_recorded_rs_lengths(size_t rs_lengths);
473 475 void set_predicted_bytes_to_copy(size_t bytes);
474 476
475 477 void end_recording_regions();
476 478
477 479 void record_vtime_diff_ms(double vtime_diff_ms) {
478 480 _vtime_diff_ms = vtime_diff_ms;
479 481 }
480 482
481 483 void record_young_free_cset_time_ms(double time_ms) {
482 484 _recorded_young_free_cset_time_ms = time_ms;
483 485 }
484 486
485 487 void record_non_young_free_cset_time_ms(double time_ms) {
486 488 _recorded_non_young_free_cset_time_ms = time_ms;
487 489 }
488 490
489 491 double predict_young_gc_eff() {
490 492 return get_new_neg_prediction(_young_gc_eff_seq);
491 493 }
492 494
493 495 double predict_survivor_regions_evac_time();
494 496
495 497 // </NEW PREDICTION>
496 498
497 499 void cset_regions_freed() {
498 500 bool propagate = _last_young_gc_full && !_in_marking_window;
499 501 _short_lived_surv_rate_group->all_surviving_words_recorded(propagate);
500 502 _survivor_surv_rate_group->all_surviving_words_recorded(propagate);
501 503 // also call it on any more surv rate groups
502 504 }
503 505
504 506 void set_known_garbage_bytes(size_t known_garbage_bytes) {
505 507 _known_garbage_bytes = known_garbage_bytes;
506 508 size_t heap_bytes = _g1->capacity();
507 509 _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes;
508 510 }
509 511
510 512 void decrease_known_garbage_bytes(size_t known_garbage_bytes) {
511 513 guarantee( _known_garbage_bytes >= known_garbage_bytes, "invariant" );
512 514
513 515 _known_garbage_bytes -= known_garbage_bytes;
514 516 size_t heap_bytes = _g1->capacity();
515 517 _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes;
516 518 }
517 519
518 520 G1MMUTracker* mmu_tracker() {
519 521 return _mmu_tracker;
520 522 }
521 523
522 524 double max_pause_time_ms() {
523 525 return _mmu_tracker->max_gc_time() * 1000.0;
524 526 }
525 527
526 528 double predict_remark_time_ms() {
527 529 return get_new_prediction(_concurrent_mark_remark_times_ms);
528 530 }
529 531
530 532 double predict_cleanup_time_ms() {
531 533 return get_new_prediction(_concurrent_mark_cleanup_times_ms);
532 534 }
533 535
534 536 // Returns an estimate of the survival rate of the region at yg-age
535 537 // "yg_age".
536 538 double predict_yg_surv_rate(int age, SurvRateGroup* surv_rate_group) {
537 539 TruncatedSeq* seq = surv_rate_group->get_seq(age);
538 540 if (seq->num() == 0)
539 541 gclog_or_tty->print("BARF! age is %d", age);
540 542 guarantee( seq->num() > 0, "invariant" );
541 543 double pred = get_new_prediction(seq);
542 544 if (pred > 1.0)
543 545 pred = 1.0;
544 546 return pred;
545 547 }
546 548
547 549 double predict_yg_surv_rate(int age) {
548 550 return predict_yg_surv_rate(age, _short_lived_surv_rate_group);
549 551 }
550 552
551 553 double accum_yg_surv_rate_pred(int age) {
552 554 return _short_lived_surv_rate_group->accum_surv_rate_pred(age);
553 555 }
554 556
555 557 protected:
556 558 void print_stats(int level, const char* str, double value);
557 559 void print_stats(int level, const char* str, int value);
558 560
559 561 void print_par_stats(int level, const char* str, double* data);
560 562 void print_par_sizes(int level, const char* str, double* data);
561 563
562 564 void check_other_times(int level,
563 565 NumberSeq* other_times_ms,
564 566 NumberSeq* calc_other_times_ms) const;
565 567
566 568 void print_summary (PauseSummary* stats) const;
567 569
568 570 void print_summary (int level, const char* str, NumberSeq* seq) const;
569 571 void print_summary_sd (int level, const char* str, NumberSeq* seq) const;
570 572
571 573 double avg_value (double* data);
572 574 double max_value (double* data);
573 575 double sum_of_values (double* data);
574 576 double max_sum (double* data1, double* data2);
575 577
576 578 int _last_satb_drain_processed_buffers;
577 579 int _last_update_rs_processed_buffers;
578 580 double _last_pause_time_ms;
579 581
580 582 size_t _bytes_in_collection_set_before_gc;
581 583 size_t _bytes_copied_during_gc;
582 584
583 585 // Used to count used bytes in CS.
584 586 friend class CountCSClosure;
585 587
586 588 // Statistics kept per GC stoppage, pause or full.
587 589 TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec;
588 590
589 591 // We track markings.
590 592 int _num_markings;
591 593 double _mark_thread_startup_sec; // Time at startup of marking thread
592 594
593 595 // Add a new GC of the given duration and end time to the record.
594 596 void update_recent_gc_times(double end_time_sec, double elapsed_ms);
595 597
596 598 // The head of the list (via "next_in_collection_set()") representing the
597 599 // current collection set. Set from the incrementally built collection
598 600 // set at the start of the pause.
599 601 HeapRegion* _collection_set;
600 602
601 603 // The number of regions in the collection set. Set from the incrementally
602 604 // built collection set at the start of an evacuation pause.
603 605 size_t _collection_set_size;
604 606
605 607 // The number of bytes in the collection set before the pause. Set from
606 608 // the incrementally built collection set at the start of an evacuation
607 609 // pause.
608 610 size_t _collection_set_bytes_used_before;
609 611
610 612 // The associated information that is maintained while the incremental
611 613 // collection set is being built with young regions. Used to populate
612 614 // the recorded info for the evacuation pause.
613 615
614 616 enum CSetBuildType {
615 617 Active, // We are actively building the collection set
616 618 Inactive // We are not actively building the collection set
617 619 };
618 620
619 621 CSetBuildType _inc_cset_build_state;
620 622
621 623 // The head of the incrementally built collection set.
622 624 HeapRegion* _inc_cset_head;
623 625
624 626 // The tail of the incrementally built collection set.
625 627 HeapRegion* _inc_cset_tail;
626 628
627 629 // The number of regions in the incrementally built collection set.
628 630 // Used to set _collection_set_size at the start of an evacuation
629 631 // pause.
630 632 size_t _inc_cset_size;
631 633
632 634 // Used as the index in the surving young words structure
633 635 // which tracks the amount of space, for each young region,
634 636 // that survives the pause.
635 637 size_t _inc_cset_young_index;
636 638
637 639 // The number of bytes in the incrementally built collection set.
638 640 // Used to set _collection_set_bytes_used_before at the start of
639 641 // an evacuation pause.
640 642 size_t _inc_cset_bytes_used_before;
641 643
642 644 // Used to record the highest end of heap region in collection set
643 645 HeapWord* _inc_cset_max_finger;
644 646
645 647 // The number of recorded used bytes in the young regions
646 648 // of the collection set. This is the sum of the used() bytes
647 649 // of retired young regions in the collection set.
648 650 size_t _inc_cset_recorded_young_bytes;
649 651
650 652 // The RSet lengths recorded for regions in the collection set
651 653 // (updated by the periodic sampling of the regions in the
652 654 // young list/collection set).
653 655 size_t _inc_cset_recorded_rs_lengths;
654 656
655 657 // The predicted elapsed time it will take to collect the regions
656 658 // in the collection set (updated by the periodic sampling of the
657 659 // regions in the young list/collection set).
658 660 double _inc_cset_predicted_elapsed_time_ms;
659 661
660 662 // The predicted bytes to copy for the regions in the collection
661 663 // set (updated by the periodic sampling of the regions in the
662 664 // young list/collection set).
663 665 size_t _inc_cset_predicted_bytes_to_copy;
664 666
665 667 // Info about marking.
666 668 int _n_marks; // Sticky at 2, so we know when we've done at least 2.
667 669
668 670 // The number of collection pauses at the end of the last mark.
669 671 size_t _n_pauses_at_mark_end;
670 672
671 673 // Stash a pointer to the g1 heap.
672 674 G1CollectedHeap* _g1;
673 675
674 676 // The average time in ms per collection pause, averaged over recent pauses.
675 677 double recent_avg_time_for_pauses_ms();
676 678
677 679 // The average time in ms for RS scanning, per pause, averaged
678 680 // over recent pauses. (Note the RS scanning time for a pause
679 681 // is itself an average of the RS scanning time for each worker
680 682 // thread.)
681 683 double recent_avg_time_for_rs_scan_ms();
682 684
683 685 // The number of "recent" GCs recorded in the number sequences
684 686 int number_of_recent_gcs();
685 687
686 688 // The average survival ratio, computed by the total number of bytes
687 689 // suriviving / total number of bytes before collection over the last
688 690 // several recent pauses.
689 691 double recent_avg_survival_fraction();
690 692 // The survival fraction of the most recent pause; if there have been no
691 693 // pauses, returns 1.0.
692 694 double last_survival_fraction();
693 695
694 696 // Returns a "conservative" estimate of the recent survival rate, i.e.,
695 697 // one that may be higher than "recent_avg_survival_fraction".
696 698 // This is conservative in several ways:
697 699 // If there have been few pauses, it will assume a potential high
698 700 // variance, and err on the side of caution.
699 701 // It puts a lower bound (currently 0.1) on the value it will return.
700 702 // To try to detect phase changes, if the most recent pause ("latest") has a
701 703 // higher-than average ("avg") survival rate, it returns that rate.
702 704 // "work" version is a utility function; young is restricted to young regions.
703 705 double conservative_avg_survival_fraction_work(double avg,
704 706 double latest);
705 707
706 708 // The arguments are the two sequences that keep track of the number of bytes
707 709 // surviving and the total number of bytes before collection, resp.,
708 710 // over the last evereal recent pauses
709 711 // Returns the survival rate for the category in the most recent pause.
710 712 // If there have been no pauses, returns 1.0.
711 713 double last_survival_fraction_work(TruncatedSeq* surviving,
712 714 TruncatedSeq* before);
713 715
714 716 // The arguments are the two sequences that keep track of the number of bytes
715 717 // surviving and the total number of bytes before collection, resp.,
716 718 // over the last several recent pauses
717 719 // Returns the average survival ration over the last several recent pauses
718 720 // If there have been no pauses, return 1.0
719 721 double recent_avg_survival_fraction_work(TruncatedSeq* surviving,
720 722 TruncatedSeq* before);
721 723
722 724 double conservative_avg_survival_fraction() {
723 725 double avg = recent_avg_survival_fraction();
724 726 double latest = last_survival_fraction();
725 727 return conservative_avg_survival_fraction_work(avg, latest);
726 728 }
727 729
728 730 // The ratio of gc time to elapsed time, computed over recent pauses.
729 731 double _recent_avg_pause_time_ratio;
730 732
731 733 double recent_avg_pause_time_ratio() {
732 734 return _recent_avg_pause_time_ratio;
733 735 }
734 736
735 737 // Number of pauses between concurrent marking.
736 738 size_t _pauses_btwn_concurrent_mark;
737 739
738 740 size_t _n_marks_since_last_pause;
739 741
740 742 // At the end of a pause we check the heap occupancy and we decide
741 743 // whether we will start a marking cycle during the next pause. If
742 744 // we decide that we want to do that, we will set this parameter to
743 745 // true. So, this parameter will stay true between the end of a
744 746 // pause and the beginning of a subsequent pause (not necessarily
745 747 // the next one, see the comments on the next field) when we decide
746 748 // that we will indeed start a marking cycle and do the initial-mark
747 749 // work.
748 750 volatile bool _initiate_conc_mark_if_possible;
749 751
750 752 // If initiate_conc_mark_if_possible() is set at the beginning of a
751 753 // pause, it is a suggestion that the pause should start a marking
752 754 // cycle by doing the initial-mark work. However, it is possible
753 755 // that the concurrent marking thread is still finishing up the
754 756 // previous marking cycle (e.g., clearing the next marking
755 757 // bitmap). If that is the case we cannot start a new cycle and
756 758 // we'll have to wait for the concurrent marking thread to finish
757 759 // what it is doing. In this case we will postpone the marking cycle
758 760 // initiation decision for the next pause. When we eventually decide
759 761 // to start a cycle, we will set _during_initial_mark_pause which
760 762 // will stay true until the end of the initial-mark pause and it's
761 763 // the condition that indicates that a pause is doing the
762 764 // initial-mark work.
763 765 volatile bool _during_initial_mark_pause;
764 766
765 767 bool _should_revert_to_full_young_gcs;
766 768 bool _last_full_young_gc;
767 769
768 770 // This set of variables tracks the collector efficiency, in order to
769 771 // determine whether we should initiate a new marking.
770 772 double _cur_mark_stop_world_time_ms;
771 773 double _mark_remark_start_sec;
772 774 double _mark_cleanup_start_sec;
773 775 double _mark_closure_time_ms;
774 776
775 777 // Update the young list target length either by setting it to the
776 778 // desired fixed value or by calculating it using G1's pause
777 779 // prediction model. If no rs_lengths parameter is passed, predict
778 780 // the RS lengths using the prediction model, otherwise use the
779 781 // given rs_lengths as the prediction.
780 782 void update_young_list_target_length(size_t rs_lengths = (size_t) -1);
781 783
782 784 // Calculate and return the minimum desired young list target
783 785 // length. This is the minimum desired young list length according
784 786 // to the user's inputs.
785 787 size_t calculate_young_list_desired_min_length(size_t base_min_length);
786 788
787 789 // Calculate and return the maximum desired young list target
788 790 // length. This is the maximum desired young list length according
789 791 // to the user's inputs.
790 792 size_t calculate_young_list_desired_max_length();
791 793
792 794 // Calculate and return the maximum young list target length that
793 795 // can fit into the pause time goal. The parameters are: rs_lengths
794 796 // represent the prediction of how large the young RSet lengths will
795 797 // be, base_min_length is the alreay existing number of regions in
796 798 // the young list, min_length and max_length are the desired min and
797 799 // max young list length according to the user's inputs.
798 800 size_t calculate_young_list_target_length(size_t rs_lengths,
799 801 size_t base_min_length,
800 802 size_t desired_min_length,
801 803 size_t desired_max_length);
802 804
803 805 // Check whether a given young length (young_length) fits into the
804 806 // given target pause time and whether the prediction for the amount
805 807 // of objects to be copied for the given length will fit into the
806 808 // given free space (expressed by base_free_regions). It is used by
807 809 // calculate_young_list_target_length().
808 810 bool predict_will_fit(size_t young_length, double base_time_ms,
809 811 size_t base_free_regions, double target_pause_time_ms);
810 812
811 813 public:
812 814
813 815 G1CollectorPolicy();
814 816
815 817 virtual G1CollectorPolicy* as_g1_policy() { return this; }
816 818
817 819 virtual CollectorPolicy::Name kind() {
818 820 return CollectorPolicy::G1CollectorPolicyKind;
819 821 }
820 822
821 823 // Check the current value of the young list RSet lengths and
822 824 // compare it against the last prediction. If the current value is
823 825 // higher, recalculate the young list target length prediction.
824 826 void revise_young_list_target_length_if_necessary();
825 827
826 828 size_t bytes_in_collection_set() {
827 829 return _bytes_in_collection_set_before_gc;
828 830 }
829 831
830 832 unsigned calc_gc_alloc_time_stamp() {
831 833 return _all_pause_times_ms->num() + 1;
832 834 }
833 835
834 836 // This should be called after the heap is resized.
835 837 void record_new_heap_size(size_t new_number_of_regions);
836 838
837 839 protected:
838 840
839 841 // Count the number of bytes used in the CS.
840 842 void count_CS_bytes_used();
841 843
842 844 // Together these do the base cleanup-recording work. Subclasses might
843 845 // want to put something between them.
844 846 void record_concurrent_mark_cleanup_end_work1(size_t freed_bytes,
845 847 size_t max_live_bytes);
846 848 void record_concurrent_mark_cleanup_end_work2();
847 849
848 850 void update_young_list_size_using_newratio(size_t number_of_heap_regions);
849 851
850 852 public:
851 853
852 854 virtual void init();
853 855
854 856 // Create jstat counters for the policy.
855 857 virtual void initialize_gc_policy_counters();
856 858
857 859 virtual HeapWord* mem_allocate_work(size_t size,
858 860 bool is_tlab,
859 861 bool* gc_overhead_limit_was_exceeded);
860 862
861 863 // This method controls how a collector handles one or more
862 864 // of its generations being fully allocated.
863 865 virtual HeapWord* satisfy_failed_allocation(size_t size,
864 866 bool is_tlab);
865 867
866 868 BarrierSet::Name barrier_set_name() { return BarrierSet::G1SATBCTLogging; }
867 869
868 870 GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; }
869 871
870 872 // The number of collection pauses so far.
871 873 long n_pauses() const { return _n_pauses; }
872 874
873 875 // Update the heuristic info to record a collection pause of the given
874 876 // start time, where the given number of bytes were used at the start.
875 877 // This may involve changing the desired size of a collection set.
876 878
877 879 virtual void record_stop_world_start();
878 880
879 881 virtual void record_collection_pause_start(double start_time_sec,
880 882 size_t start_used);
881 883
882 884 // Must currently be called while the world is stopped.
883 885 void record_concurrent_mark_init_end(double
884 886 mark_init_elapsed_time_ms);
885 887
886 888 void record_mark_closure_time(double mark_closure_time_ms);
887 889
888 890 virtual void record_concurrent_mark_remark_start();
889 891 virtual void record_concurrent_mark_remark_end();
890 892
891 893 virtual void record_concurrent_mark_cleanup_start();
892 894 virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,
893 895 size_t max_live_bytes);
894 896 virtual void record_concurrent_mark_cleanup_completed();
895 897
896 898 virtual void record_concurrent_pause();
897 899 virtual void record_concurrent_pause_end();
898 900
899 901 virtual void record_collection_pause_end();
900 902 void print_heap_transition();
901 903
902 904 // Record the fact that a full collection occurred.
903 905 virtual void record_full_collection_start();
904 906 virtual void record_full_collection_end();
905 907
906 908 void record_gc_worker_start_time(int worker_i, double ms) {
907 909 _par_last_gc_worker_start_times_ms[worker_i] = ms;
908 910 }
909 911
910 912 void record_ext_root_scan_time(int worker_i, double ms) {
911 913 _par_last_ext_root_scan_times_ms[worker_i] = ms;
912 914 }
913 915
914 916 void record_mark_stack_scan_time(int worker_i, double ms) {
915 917 _par_last_mark_stack_scan_times_ms[worker_i] = ms;
916 918 }
917 919
918 920 void record_satb_drain_time(double ms) {
919 921 _cur_satb_drain_time_ms = ms;
920 922 _satb_drain_time_set = true;
921 923 }
922 924
923 925 void record_satb_drain_processed_buffers (int processed_buffers) {
924 926 _last_satb_drain_processed_buffers = processed_buffers;
925 927 }
926 928
927 929 void record_mod_union_time(double ms) {
928 930 _all_mod_union_times_ms->add(ms);
929 931 }
930 932
931 933 void record_update_rs_time(int thread, double ms) {
932 934 _par_last_update_rs_times_ms[thread] = ms;
933 935 }
934 936
935 937 void record_update_rs_processed_buffers (int thread,
936 938 double processed_buffers) {
937 939 _par_last_update_rs_processed_buffers[thread] = processed_buffers;
938 940 }
939 941
940 942 void record_scan_rs_time(int thread, double ms) {
941 943 _par_last_scan_rs_times_ms[thread] = ms;
942 944 }
943 945
944 946 void reset_obj_copy_time(int thread) {
945 947 _par_last_obj_copy_times_ms[thread] = 0.0;
946 948 }
947 949
948 950 void reset_obj_copy_time() {
949 951 reset_obj_copy_time(0);
950 952 }
951 953
952 954 void record_obj_copy_time(int thread, double ms) {
953 955 _par_last_obj_copy_times_ms[thread] += ms;
954 956 }
955 957
956 958 void record_termination(int thread, double ms, size_t attempts) {
957 959 _par_last_termination_times_ms[thread] = ms;
958 960 _par_last_termination_attempts[thread] = (double) attempts;
959 961 }
960 962
961 963 void record_gc_worker_end_time(int worker_i, double ms) {
962 964 _par_last_gc_worker_end_times_ms[worker_i] = ms;
963 965 }
964 966
965 967 void record_pause_time_ms(double ms) {
966 968 _last_pause_time_ms = ms;
967 969 }
968 970
969 971 void record_clear_ct_time(double ms) {
970 972 _cur_clear_ct_time_ms = ms;
971 973 }
972 974
973 975 void record_par_time(double ms) {
974 976 _cur_collection_par_time_ms = ms;
975 977 }
976 978
977 979 void record_aux_start_time(int i) {
978 980 guarantee(i < _aux_num, "should be within range");
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979 981 _cur_aux_start_times_ms[i] = os::elapsedTime() * 1000.0;
980 982 }
981 983
982 984 void record_aux_end_time(int i) {
983 985 guarantee(i < _aux_num, "should be within range");
984 986 double ms = os::elapsedTime() * 1000.0 - _cur_aux_start_times_ms[i];
985 987 _cur_aux_times_set[i] = true;
986 988 _cur_aux_times_ms[i] += ms;
987 989 }
988 990
991 + void record_ref_proc_time(double ms) {
992 + _cur_ref_proc_time_ms = ms;
993 + }
994 +
995 + void record_ref_enq_time(double ms) {
996 + _cur_ref_enq_time_ms = ms;
997 + }
998 +
989 999 #ifndef PRODUCT
990 1000 void record_cc_clear_time(double ms) {
991 1001 if (_min_clear_cc_time_ms < 0.0 || ms <= _min_clear_cc_time_ms)
992 1002 _min_clear_cc_time_ms = ms;
993 1003 if (_max_clear_cc_time_ms < 0.0 || ms >= _max_clear_cc_time_ms)
994 1004 _max_clear_cc_time_ms = ms;
995 1005 _cur_clear_cc_time_ms = ms;
996 1006 _cum_clear_cc_time_ms += ms;
997 1007 _num_cc_clears++;
998 1008 }
999 1009 #endif
1000 1010
1001 1011 // Record how much space we copied during a GC. This is typically
1002 1012 // called when a GC alloc region is being retired.
1003 1013 void record_bytes_copied_during_gc(size_t bytes) {
1004 1014 _bytes_copied_during_gc += bytes;
1005 1015 }
1006 1016
1007 1017 // The amount of space we copied during a GC.
1008 1018 size_t bytes_copied_during_gc() {
1009 1019 return _bytes_copied_during_gc;
1010 1020 }
1011 1021
1012 1022 // Choose a new collection set. Marks the chosen regions as being
1013 1023 // "in_collection_set", and links them together. The head and number of
1014 1024 // the collection set are available via access methods.
1015 1025 virtual void choose_collection_set(double target_pause_time_ms) = 0;
1016 1026
1017 1027 // The head of the list (via "next_in_collection_set()") representing the
1018 1028 // current collection set.
1019 1029 HeapRegion* collection_set() { return _collection_set; }
1020 1030
1021 1031 void clear_collection_set() { _collection_set = NULL; }
1022 1032
1023 1033 // The number of elements in the current collection set.
1024 1034 size_t collection_set_size() { return _collection_set_size; }
1025 1035
1026 1036 // Add "hr" to the CS.
1027 1037 void add_to_collection_set(HeapRegion* hr);
1028 1038
1029 1039 // Incremental CSet Support
1030 1040
1031 1041 // The head of the incrementally built collection set.
1032 1042 HeapRegion* inc_cset_head() { return _inc_cset_head; }
1033 1043
1034 1044 // The tail of the incrementally built collection set.
1035 1045 HeapRegion* inc_set_tail() { return _inc_cset_tail; }
1036 1046
1037 1047 // The number of elements in the incrementally built collection set.
1038 1048 size_t inc_cset_size() { return _inc_cset_size; }
1039 1049
1040 1050 // Initialize incremental collection set info.
1041 1051 void start_incremental_cset_building();
1042 1052
1043 1053 void clear_incremental_cset() {
1044 1054 _inc_cset_head = NULL;
1045 1055 _inc_cset_tail = NULL;
1046 1056 }
1047 1057
1048 1058 // Stop adding regions to the incremental collection set
1049 1059 void stop_incremental_cset_building() { _inc_cset_build_state = Inactive; }
1050 1060
1051 1061 // Add/remove information about hr to the aggregated information
1052 1062 // for the incrementally built collection set.
1053 1063 void add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length);
1054 1064 void remove_from_incremental_cset_info(HeapRegion* hr);
1055 1065
1056 1066 // Update information about hr in the aggregated information for
1057 1067 // the incrementally built collection set.
1058 1068 void update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length);
1059 1069
1060 1070 private:
1061 1071 // Update the incremental cset information when adding a region
1062 1072 // (should not be called directly).
1063 1073 void add_region_to_incremental_cset_common(HeapRegion* hr);
1064 1074
1065 1075 public:
1066 1076 // Add hr to the LHS of the incremental collection set.
1067 1077 void add_region_to_incremental_cset_lhs(HeapRegion* hr);
1068 1078
1069 1079 // Add hr to the RHS of the incremental collection set.
1070 1080 void add_region_to_incremental_cset_rhs(HeapRegion* hr);
1071 1081
1072 1082 #ifndef PRODUCT
1073 1083 void print_collection_set(HeapRegion* list_head, outputStream* st);
1074 1084 #endif // !PRODUCT
1075 1085
1076 1086 bool initiate_conc_mark_if_possible() { return _initiate_conc_mark_if_possible; }
1077 1087 void set_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = true; }
1078 1088 void clear_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = false; }
1079 1089
1080 1090 bool during_initial_mark_pause() { return _during_initial_mark_pause; }
1081 1091 void set_during_initial_mark_pause() { _during_initial_mark_pause = true; }
1082 1092 void clear_during_initial_mark_pause(){ _during_initial_mark_pause = false; }
1083 1093
1084 1094 // This sets the initiate_conc_mark_if_possible() flag to start a
1085 1095 // new cycle, as long as we are not already in one. It's best if it
1086 1096 // is called during a safepoint when the test whether a cycle is in
1087 1097 // progress or not is stable.
1088 1098 bool force_initial_mark_if_outside_cycle(GCCause::Cause gc_cause);
1089 1099
1090 1100 // This is called at the very beginning of an evacuation pause (it
1091 1101 // has to be the first thing that the pause does). If
1092 1102 // initiate_conc_mark_if_possible() is true, and the concurrent
1093 1103 // marking thread has completed its work during the previous cycle,
1094 1104 // it will set during_initial_mark_pause() to so that the pause does
1095 1105 // the initial-mark work and start a marking cycle.
1096 1106 void decide_on_conc_mark_initiation();
1097 1107
1098 1108 // If an expansion would be appropriate, because recent GC overhead had
1099 1109 // exceeded the desired limit, return an amount to expand by.
1100 1110 virtual size_t expansion_amount();
1101 1111
1102 1112 // note start of mark thread
1103 1113 void note_start_of_mark_thread();
1104 1114
1105 1115 // The marked bytes of the "r" has changed; reclassify it's desirability
1106 1116 // for marking. Also asserts that "r" is eligible for a CS.
1107 1117 virtual void note_change_in_marked_bytes(HeapRegion* r) = 0;
1108 1118
1109 1119 #ifndef PRODUCT
1110 1120 // Check any appropriate marked bytes info, asserting false if
1111 1121 // something's wrong, else returning "true".
1112 1122 virtual bool assertMarkedBytesDataOK() = 0;
1113 1123 #endif
1114 1124
1115 1125 // Print tracing information.
1116 1126 void print_tracing_info() const;
1117 1127
1118 1128 // Print stats on young survival ratio
1119 1129 void print_yg_surv_rate_info() const;
1120 1130
1121 1131 void finished_recalculating_age_indexes(bool is_survivors) {
1122 1132 if (is_survivors) {
1123 1133 _survivor_surv_rate_group->finished_recalculating_age_indexes();
1124 1134 } else {
1125 1135 _short_lived_surv_rate_group->finished_recalculating_age_indexes();
1126 1136 }
1127 1137 // do that for any other surv rate groups
1128 1138 }
1129 1139
1130 1140 bool is_young_list_full() {
1131 1141 size_t young_list_length = _g1->young_list()->length();
1132 1142 size_t young_list_target_length = _young_list_target_length;
1133 1143 return young_list_length >= young_list_target_length;
1134 1144 }
1135 1145
1136 1146 bool can_expand_young_list() {
1137 1147 size_t young_list_length = _g1->young_list()->length();
1138 1148 size_t young_list_max_length = _young_list_max_length;
1139 1149 return young_list_length < young_list_max_length;
1140 1150 }
1141 1151
1142 1152 void update_region_num(bool young);
1143 1153
1144 1154 bool full_young_gcs() {
1145 1155 return _full_young_gcs;
1146 1156 }
1147 1157 void set_full_young_gcs(bool full_young_gcs) {
1148 1158 _full_young_gcs = full_young_gcs;
1149 1159 }
1150 1160
1151 1161 bool adaptive_young_list_length() {
1152 1162 return _adaptive_young_list_length;
1153 1163 }
1154 1164 void set_adaptive_young_list_length(bool adaptive_young_list_length) {
1155 1165 _adaptive_young_list_length = adaptive_young_list_length;
1156 1166 }
1157 1167
1158 1168 inline double get_gc_eff_factor() {
1159 1169 double ratio = _known_garbage_ratio;
1160 1170
1161 1171 double square = ratio * ratio;
1162 1172 // square = square * square;
1163 1173 double ret = square * 9.0 + 1.0;
1164 1174 #if 0
1165 1175 gclog_or_tty->print_cr("ratio = %1.2lf, ret = %1.2lf", ratio, ret);
1166 1176 #endif // 0
1167 1177 guarantee(0.0 <= ret && ret < 10.0, "invariant!");
1168 1178 return ret;
1169 1179 }
1170 1180
1171 1181 //
1172 1182 // Survivor regions policy.
1173 1183 //
1174 1184 protected:
1175 1185
1176 1186 // Current tenuring threshold, set to 0 if the collector reaches the
1177 1187 // maximum amount of suvivors regions.
1178 1188 int _tenuring_threshold;
1179 1189
1180 1190 // The limit on the number of regions allocated for survivors.
1181 1191 size_t _max_survivor_regions;
1182 1192
1183 1193 // For reporting purposes.
1184 1194 size_t _eden_bytes_before_gc;
1185 1195 size_t _survivor_bytes_before_gc;
1186 1196 size_t _capacity_before_gc;
1187 1197
1188 1198 // The amount of survor regions after a collection.
1189 1199 size_t _recorded_survivor_regions;
1190 1200 // List of survivor regions.
1191 1201 HeapRegion* _recorded_survivor_head;
1192 1202 HeapRegion* _recorded_survivor_tail;
1193 1203
1194 1204 ageTable _survivors_age_table;
1195 1205
1196 1206 public:
1197 1207
1198 1208 inline GCAllocPurpose
1199 1209 evacuation_destination(HeapRegion* src_region, int age, size_t word_sz) {
1200 1210 if (age < _tenuring_threshold && src_region->is_young()) {
1201 1211 return GCAllocForSurvived;
1202 1212 } else {
1203 1213 return GCAllocForTenured;
1204 1214 }
1205 1215 }
1206 1216
1207 1217 inline bool track_object_age(GCAllocPurpose purpose) {
1208 1218 return purpose == GCAllocForSurvived;
1209 1219 }
1210 1220
1211 1221 static const size_t REGIONS_UNLIMITED = ~(size_t)0;
1212 1222
1213 1223 size_t max_regions(int purpose);
1214 1224
1215 1225 // The limit on regions for a particular purpose is reached.
1216 1226 void note_alloc_region_limit_reached(int purpose) {
1217 1227 if (purpose == GCAllocForSurvived) {
1218 1228 _tenuring_threshold = 0;
1219 1229 }
1220 1230 }
1221 1231
1222 1232 void note_start_adding_survivor_regions() {
1223 1233 _survivor_surv_rate_group->start_adding_regions();
1224 1234 }
1225 1235
1226 1236 void note_stop_adding_survivor_regions() {
1227 1237 _survivor_surv_rate_group->stop_adding_regions();
1228 1238 }
1229 1239
1230 1240 void record_survivor_regions(size_t regions,
1231 1241 HeapRegion* head,
1232 1242 HeapRegion* tail) {
1233 1243 _recorded_survivor_regions = regions;
1234 1244 _recorded_survivor_head = head;
1235 1245 _recorded_survivor_tail = tail;
1236 1246 }
1237 1247
1238 1248 size_t recorded_survivor_regions() {
1239 1249 return _recorded_survivor_regions;
1240 1250 }
1241 1251
1242 1252 void record_thread_age_table(ageTable* age_table)
1243 1253 {
1244 1254 _survivors_age_table.merge_par(age_table);
1245 1255 }
1246 1256
1247 1257 void update_max_gc_locker_expansion();
1248 1258
1249 1259 // Calculates survivor space parameters.
1250 1260 void update_survivors_policy();
1251 1261
1252 1262 };
1253 1263
1254 1264 // This encapsulates a particular strategy for a g1 Collector.
1255 1265 //
1256 1266 // Start a concurrent mark when our heap size is n bytes
1257 1267 // greater then our heap size was at the last concurrent
1258 1268 // mark. Where n is a function of the CMSTriggerRatio
1259 1269 // and the MinHeapFreeRatio.
1260 1270 //
1261 1271 // Start a g1 collection pause when we have allocated the
1262 1272 // average number of bytes currently being freed in
1263 1273 // a collection, but only if it is at least one region
1264 1274 // full
1265 1275 //
1266 1276 // Resize Heap based on desired
1267 1277 // allocation space, where desired allocation space is
1268 1278 // a function of survival rate and desired future to size.
1269 1279 //
1270 1280 // Choose collection set by first picking all older regions
1271 1281 // which have a survival rate which beats our projected young
1272 1282 // survival rate. Then fill out the number of needed regions
1273 1283 // with young regions.
1274 1284
1275 1285 class G1CollectorPolicy_BestRegionsFirst: public G1CollectorPolicy {
1276 1286 CollectionSetChooser* _collectionSetChooser;
1277 1287
1278 1288 virtual void choose_collection_set(double target_pause_time_ms);
1279 1289 virtual void record_collection_pause_start(double start_time_sec,
1280 1290 size_t start_used);
1281 1291 virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,
1282 1292 size_t max_live_bytes);
1283 1293 virtual void record_full_collection_end();
1284 1294
1285 1295 public:
1286 1296 G1CollectorPolicy_BestRegionsFirst() {
1287 1297 _collectionSetChooser = new CollectionSetChooser();
1288 1298 }
1289 1299 void record_collection_pause_end();
1290 1300 // This is not needed any more, after the CSet choosing code was
1291 1301 // changed to use the pause prediction work. But let's leave the
1292 1302 // hook in just in case.
1293 1303 void note_change_in_marked_bytes(HeapRegion* r) { }
1294 1304 #ifndef PRODUCT
1295 1305 bool assertMarkedBytesDataOK();
1296 1306 #endif
1297 1307 };
1298 1308
1299 1309 // This should move to some place more general...
1300 1310
1301 1311 // If we have "n" measurements, and we've kept track of their "sum" and the
1302 1312 // "sum_of_squares" of the measurements, this returns the variance of the
1303 1313 // sequence.
1304 1314 inline double variance(int n, double sum_of_squares, double sum) {
1305 1315 double n_d = (double)n;
1306 1316 double avg = sum/n_d;
1307 1317 return (sum_of_squares - 2.0 * avg * sum + n_d * avg * avg) / n_d;
1308 1318 }
1309 1319
1310 1320 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP
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