Mercurial > hg > graal-jvmci-8
annotate src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp @ 3960:f08d439fab8c
7089790: integrate bsd-port changes
Reviewed-by: kvn, twisti, jrose
Contributed-by: Kurt Miller <kurt@intricatesoftware.com>, Greg Lewis <glewis@eyesbeyond.com>, Jung-uk Kim <jkim@freebsd.org>, Christos Zoulas <christos@zoulas.com>, Landon Fuller <landonf@plausible.coop>, The FreeBSD Foundation <board@freebsdfoundation.org>, Michael Franz <mvfranz@gmail.com>, Roger Hoover <rhoover@apple.com>, Alexander Strange <astrange@apple.com>
author | never |
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date | Sun, 25 Sep 2011 16:03:29 -0700 |
parents | af2ab04e0038 |
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342 | 1 /* |
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2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. 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 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
342 | 22 * |
23 */ | |
24 | |
1972 | 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP |
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP | |
27 | |
28 #include "gc_implementation/g1/collectionSetChooser.hpp" | |
29 #include "gc_implementation/g1/g1MMUTracker.hpp" | |
30 #include "memory/collectorPolicy.hpp" | |
31 | |
342 | 32 // A G1CollectorPolicy makes policy decisions that determine the |
33 // characteristics of the collector. Examples include: | |
34 // * choice of collection set. | |
35 // * when to collect. | |
36 | |
37 class HeapRegion; | |
38 class CollectionSetChooser; | |
39 | |
40 // Yes, this is a bit unpleasant... but it saves replicating the same thing | |
41 // over and over again and introducing subtle problems through small typos and | |
42 // cutting and pasting mistakes. The macros below introduces a number | |
43 // sequnce into the following two classes and the methods that access it. | |
44 | |
45 #define define_num_seq(name) \ | |
46 private: \ | |
47 NumberSeq _all_##name##_times_ms; \ | |
48 public: \ | |
49 void record_##name##_time_ms(double ms) { \ | |
50 _all_##name##_times_ms.add(ms); \ | |
51 } \ | |
52 NumberSeq* get_##name##_seq() { \ | |
53 return &_all_##name##_times_ms; \ | |
54 } | |
55 | |
56 class MainBodySummary; | |
57 | |
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58 class PauseSummary: public CHeapObj { |
342 | 59 define_num_seq(total) |
60 define_num_seq(other) | |
61 | |
62 public: | |
63 virtual MainBodySummary* main_body_summary() { return NULL; } | |
64 }; | |
65 | |
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66 class MainBodySummary: public CHeapObj { |
342 | 67 define_num_seq(satb_drain) // optional |
68 define_num_seq(parallel) // parallel only | |
69 define_num_seq(ext_root_scan) | |
70 define_num_seq(mark_stack_scan) | |
71 define_num_seq(update_rs) | |
72 define_num_seq(scan_rs) | |
73 define_num_seq(obj_copy) | |
74 define_num_seq(termination) // parallel only | |
75 define_num_seq(parallel_other) // parallel only | |
76 define_num_seq(mark_closure) | |
77 define_num_seq(clear_ct) // parallel only | |
78 }; | |
79 | |
677 | 80 class Summary: public PauseSummary, |
81 public MainBodySummary { | |
342 | 82 public: |
83 virtual MainBodySummary* main_body_summary() { return this; } | |
84 }; | |
85 | |
86 class G1CollectorPolicy: public CollectorPolicy { | |
87 protected: | |
88 // The number of pauses during the execution. | |
89 long _n_pauses; | |
90 | |
91 // either equal to the number of parallel threads, if ParallelGCThreads | |
92 // has been set, or 1 otherwise | |
93 int _parallel_gc_threads; | |
94 | |
95 enum SomePrivateConstants { | |
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96 NumPrevPausesForHeuristics = 10 |
342 | 97 }; |
98 | |
99 G1MMUTracker* _mmu_tracker; | |
100 | |
101 void initialize_flags(); | |
102 | |
103 void initialize_all() { | |
104 initialize_flags(); | |
105 initialize_size_info(); | |
106 initialize_perm_generation(PermGen::MarkSweepCompact); | |
107 } | |
108 | |
109 virtual size_t default_init_heap_size() { | |
110 // Pick some reasonable default. | |
111 return 8*M; | |
112 } | |
113 | |
114 double _cur_collection_start_sec; | |
115 size_t _cur_collection_pause_used_at_start_bytes; | |
116 size_t _cur_collection_pause_used_regions_at_start; | |
117 size_t _prev_collection_pause_used_at_end_bytes; | |
118 double _cur_collection_par_time_ms; | |
119 double _cur_satb_drain_time_ms; | |
120 double _cur_clear_ct_time_ms; | |
121 bool _satb_drain_time_set; | |
122 | |
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123 #ifndef PRODUCT |
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124 // Card Table Count Cache stats |
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125 double _min_clear_cc_time_ms; // min |
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126 double _max_clear_cc_time_ms; // max |
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127 double _cur_clear_cc_time_ms; // clearing time during current pause |
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128 double _cum_clear_cc_time_ms; // cummulative clearing time |
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129 jlong _num_cc_clears; // number of times the card count cache has been cleared |
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130 #endif |
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131 |
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132 // Statistics for recent GC pauses. See below for how indexed. |
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133 TruncatedSeq* _recent_rs_scan_times_ms; |
342 | 134 |
135 // These exclude marking times. | |
136 TruncatedSeq* _recent_pause_times_ms; | |
137 TruncatedSeq* _recent_gc_times_ms; | |
138 | |
139 TruncatedSeq* _recent_CS_bytes_used_before; | |
140 TruncatedSeq* _recent_CS_bytes_surviving; | |
141 | |
142 TruncatedSeq* _recent_rs_sizes; | |
143 | |
144 TruncatedSeq* _concurrent_mark_remark_times_ms; | |
145 TruncatedSeq* _concurrent_mark_cleanup_times_ms; | |
146 | |
677 | 147 Summary* _summary; |
342 | 148 |
149 NumberSeq* _all_pause_times_ms; | |
150 NumberSeq* _all_full_gc_times_ms; | |
151 double _stop_world_start; | |
152 NumberSeq* _all_stop_world_times_ms; | |
153 NumberSeq* _all_yield_times_ms; | |
154 | |
155 size_t _region_num_young; | |
156 size_t _region_num_tenured; | |
157 size_t _prev_region_num_young; | |
158 size_t _prev_region_num_tenured; | |
159 | |
160 NumberSeq* _all_mod_union_times_ms; | |
161 | |
162 int _aux_num; | |
163 NumberSeq* _all_aux_times_ms; | |
164 double* _cur_aux_start_times_ms; | |
165 double* _cur_aux_times_ms; | |
166 bool* _cur_aux_times_set; | |
167 | |
1611 | 168 double* _par_last_gc_worker_start_times_ms; |
342 | 169 double* _par_last_ext_root_scan_times_ms; |
170 double* _par_last_mark_stack_scan_times_ms; | |
171 double* _par_last_update_rs_times_ms; | |
172 double* _par_last_update_rs_processed_buffers; | |
173 double* _par_last_scan_rs_times_ms; | |
174 double* _par_last_obj_copy_times_ms; | |
175 double* _par_last_termination_times_ms; | |
1611 | 176 double* _par_last_termination_attempts; |
177 double* _par_last_gc_worker_end_times_ms; | |
2430 | 178 double* _par_last_gc_worker_times_ms; |
342 | 179 |
180 // indicates whether we are in full young or partially young GC mode | |
181 bool _full_young_gcs; | |
182 | |
183 // if true, then it tries to dynamically adjust the length of the | |
184 // young list | |
185 bool _adaptive_young_list_length; | |
186 size_t _young_list_target_length; | |
187 size_t _young_list_fixed_length; | |
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188 size_t _prev_eden_capacity; // used for logging |
342 | 189 |
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190 // The max number of regions we can extend the eden by while the GC |
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191 // locker is active. This should be >= _young_list_target_length; |
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192 size_t _young_list_max_length; |
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193 |
342 | 194 size_t _young_cset_length; |
195 bool _last_young_gc_full; | |
196 | |
197 unsigned _full_young_pause_num; | |
198 unsigned _partial_young_pause_num; | |
199 | |
200 bool _during_marking; | |
201 bool _in_marking_window; | |
202 bool _in_marking_window_im; | |
203 | |
204 SurvRateGroup* _short_lived_surv_rate_group; | |
205 SurvRateGroup* _survivor_surv_rate_group; | |
206 // add here any more surv rate groups | |
207 | |
1356 | 208 double _gc_overhead_perc; |
209 | |
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210 double _reserve_factor; |
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211 size_t _reserve_regions; |
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212 |
342 | 213 bool during_marking() { |
214 return _during_marking; | |
215 } | |
216 | |
217 // <NEW PREDICTION> | |
218 | |
219 private: | |
220 enum PredictionConstants { | |
221 TruncatedSeqLength = 10 | |
222 }; | |
223 | |
224 TruncatedSeq* _alloc_rate_ms_seq; | |
225 double _prev_collection_pause_end_ms; | |
226 | |
227 TruncatedSeq* _pending_card_diff_seq; | |
228 TruncatedSeq* _rs_length_diff_seq; | |
229 TruncatedSeq* _cost_per_card_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 | |
245 TruncatedSeq* _young_gc_eff_seq; | |
246 | |
247 TruncatedSeq* _max_conc_overhead_seq; | |
248 | |
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249 bool _using_new_ratio_calculations; |
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250 size_t _min_desired_young_length; // as set on the command line or default calculations |
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251 size_t _max_desired_young_length; // as set on the command line or default calculations |
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252 |
342 | 253 size_t _recorded_young_regions; |
254 size_t _recorded_non_young_regions; | |
255 size_t _recorded_region_num; | |
256 | |
257 size_t _free_regions_at_end_of_collection; | |
258 | |
259 size_t _recorded_rs_lengths; | |
260 size_t _max_rs_lengths; | |
261 | |
262 size_t _recorded_marked_bytes; | |
263 size_t _recorded_young_bytes; | |
264 | |
265 size_t _predicted_pending_cards; | |
266 size_t _predicted_cards_scanned; | |
267 size_t _predicted_rs_lengths; | |
268 size_t _predicted_bytes_to_copy; | |
269 | |
270 double _predicted_survival_ratio; | |
271 double _predicted_rs_update_time_ms; | |
272 double _predicted_rs_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 | |
1111 | 313 void adjust_concurrent_refinement(double update_rs_time, |
314 double update_rs_processed_buffers, | |
315 double goal_ms); | |
316 | |
342 | 317 protected: |
318 double _pause_time_target_ms; | |
319 double _recorded_young_cset_choice_time_ms; | |
320 double _recorded_non_young_cset_choice_time_ms; | |
321 bool _within_target; | |
322 size_t _pending_cards; | |
323 size_t _max_pending_cards; | |
324 | |
325 public: | |
326 | |
327 void set_region_short_lived(HeapRegion* hr) { | |
328 hr->install_surv_rate_group(_short_lived_surv_rate_group); | |
329 } | |
330 | |
331 void set_region_survivors(HeapRegion* hr) { | |
332 hr->install_surv_rate_group(_survivor_surv_rate_group); | |
333 } | |
334 | |
335 #ifndef PRODUCT | |
336 bool verify_young_ages(); | |
337 #endif // PRODUCT | |
338 | |
339 double get_new_prediction(TruncatedSeq* seq) { | |
340 return MAX2(seq->davg() + sigma() * seq->dsd(), | |
341 seq->davg() * confidence_factor(seq->num())); | |
342 } | |
343 | |
344 size_t young_cset_length() { | |
345 return _young_cset_length; | |
346 } | |
347 | |
348 void record_max_rs_lengths(size_t rs_lengths) { | |
349 _max_rs_lengths = rs_lengths; | |
350 } | |
351 | |
352 size_t predict_pending_card_diff() { | |
353 double prediction = get_new_neg_prediction(_pending_card_diff_seq); | |
354 if (prediction < 0.00001) | |
355 return 0; | |
356 else | |
357 return (size_t) prediction; | |
358 } | |
359 | |
360 size_t predict_pending_cards() { | |
361 size_t max_pending_card_num = _g1->max_pending_card_num(); | |
362 size_t diff = predict_pending_card_diff(); | |
363 size_t prediction; | |
364 if (diff > max_pending_card_num) | |
365 prediction = max_pending_card_num; | |
366 else | |
367 prediction = max_pending_card_num - diff; | |
368 | |
369 return prediction; | |
370 } | |
371 | |
372 size_t predict_rs_length_diff() { | |
373 return (size_t) get_new_prediction(_rs_length_diff_seq); | |
374 } | |
375 | |
376 double predict_alloc_rate_ms() { | |
377 return get_new_prediction(_alloc_rate_ms_seq); | |
378 } | |
379 | |
380 double predict_cost_per_card_ms() { | |
381 return get_new_prediction(_cost_per_card_ms_seq); | |
382 } | |
383 | |
384 double predict_rs_update_time_ms(size_t pending_cards) { | |
385 return (double) pending_cards * predict_cost_per_card_ms(); | |
386 } | |
387 | |
388 double predict_fully_young_cards_per_entry_ratio() { | |
389 return get_new_prediction(_fully_young_cards_per_entry_ratio_seq); | |
390 } | |
391 | |
392 double predict_partially_young_cards_per_entry_ratio() { | |
393 if (_partially_young_cards_per_entry_ratio_seq->num() < 2) | |
394 return predict_fully_young_cards_per_entry_ratio(); | |
395 else | |
396 return get_new_prediction(_partially_young_cards_per_entry_ratio_seq); | |
397 } | |
398 | |
399 size_t predict_young_card_num(size_t rs_length) { | |
400 return (size_t) ((double) rs_length * | |
401 predict_fully_young_cards_per_entry_ratio()); | |
402 } | |
403 | |
404 size_t predict_non_young_card_num(size_t rs_length) { | |
405 return (size_t) ((double) rs_length * | |
406 predict_partially_young_cards_per_entry_ratio()); | |
407 } | |
408 | |
409 double predict_rs_scan_time_ms(size_t card_num) { | |
410 if (full_young_gcs()) | |
411 return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq); | |
412 else | |
413 return predict_partially_young_rs_scan_time_ms(card_num); | |
414 } | |
415 | |
416 double predict_partially_young_rs_scan_time_ms(size_t card_num) { | |
417 if (_partially_young_cost_per_entry_ms_seq->num() < 3) | |
418 return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq); | |
419 else | |
420 return (double) card_num * | |
421 get_new_prediction(_partially_young_cost_per_entry_ms_seq); | |
422 } | |
423 | |
424 double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) { | |
425 if (_cost_per_byte_ms_during_cm_seq->num() < 3) | |
426 return 1.1 * (double) bytes_to_copy * | |
427 get_new_prediction(_cost_per_byte_ms_seq); | |
428 else | |
429 return (double) bytes_to_copy * | |
430 get_new_prediction(_cost_per_byte_ms_during_cm_seq); | |
431 } | |
432 | |
433 double predict_object_copy_time_ms(size_t bytes_to_copy) { | |
434 if (_in_marking_window && !_in_marking_window_im) | |
435 return predict_object_copy_time_ms_during_cm(bytes_to_copy); | |
436 else | |
437 return (double) bytes_to_copy * | |
438 get_new_prediction(_cost_per_byte_ms_seq); | |
439 } | |
440 | |
441 double predict_constant_other_time_ms() { | |
442 return get_new_prediction(_constant_other_time_ms_seq); | |
443 } | |
444 | |
445 double predict_young_other_time_ms(size_t young_num) { | |
446 return | |
447 (double) young_num * | |
448 get_new_prediction(_young_other_cost_per_region_ms_seq); | |
449 } | |
450 | |
451 double predict_non_young_other_time_ms(size_t non_young_num) { | |
452 return | |
453 (double) non_young_num * | |
454 get_new_prediction(_non_young_other_cost_per_region_ms_seq); | |
455 } | |
456 | |
457 void check_if_region_is_too_expensive(double predicted_time_ms); | |
458 | |
459 double predict_young_collection_elapsed_time_ms(size_t adjustment); | |
460 double predict_base_elapsed_time_ms(size_t pending_cards); | |
461 double predict_base_elapsed_time_ms(size_t pending_cards, | |
462 size_t scanned_cards); | |
463 size_t predict_bytes_to_copy(HeapRegion* hr); | |
464 double predict_region_elapsed_time_ms(HeapRegion* hr, bool young); | |
465 | |
466 void start_recording_regions(); | |
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467 void record_cset_region_info(HeapRegion* hr, bool young); |
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468 void record_non_young_cset_region(HeapRegion* hr); |
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469 |
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470 void set_recorded_young_regions(size_t n_regions); |
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471 void set_recorded_young_bytes(size_t bytes); |
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472 void set_recorded_rs_lengths(size_t rs_lengths); |
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473 void set_predicted_bytes_to_copy(size_t bytes); |
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474 |
342 | 475 void end_recording_regions(); |
476 | |
477 void record_vtime_diff_ms(double vtime_diff_ms) { | |
478 _vtime_diff_ms = vtime_diff_ms; | |
479 } | |
480 | |
481 void record_young_free_cset_time_ms(double time_ms) { | |
482 _recorded_young_free_cset_time_ms = time_ms; | |
483 } | |
484 | |
485 void record_non_young_free_cset_time_ms(double time_ms) { | |
486 _recorded_non_young_free_cset_time_ms = time_ms; | |
487 } | |
488 | |
489 double predict_young_gc_eff() { | |
490 return get_new_neg_prediction(_young_gc_eff_seq); | |
491 } | |
492 | |
545 | 493 double predict_survivor_regions_evac_time(); |
494 | |
342 | 495 // </NEW PREDICTION> |
496 | |
497 void cset_regions_freed() { | |
498 bool propagate = _last_young_gc_full && !_in_marking_window; | |
499 _short_lived_surv_rate_group->all_surviving_words_recorded(propagate); | |
500 _survivor_surv_rate_group->all_surviving_words_recorded(propagate); | |
501 // also call it on any more surv rate groups | |
502 } | |
503 | |
504 void set_known_garbage_bytes(size_t known_garbage_bytes) { | |
505 _known_garbage_bytes = known_garbage_bytes; | |
506 size_t heap_bytes = _g1->capacity(); | |
507 _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes; | |
508 } | |
509 | |
510 void decrease_known_garbage_bytes(size_t known_garbage_bytes) { | |
511 guarantee( _known_garbage_bytes >= known_garbage_bytes, "invariant" ); | |
512 | |
513 _known_garbage_bytes -= known_garbage_bytes; | |
514 size_t heap_bytes = _g1->capacity(); | |
515 _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes; | |
516 } | |
517 | |
518 G1MMUTracker* mmu_tracker() { | |
519 return _mmu_tracker; | |
520 } | |
521 | |
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522 double max_pause_time_ms() { |
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523 return _mmu_tracker->max_gc_time() * 1000.0; |
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524 } |
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525 |
342 | 526 double predict_remark_time_ms() { |
527 return get_new_prediction(_concurrent_mark_remark_times_ms); | |
528 } | |
529 | |
530 double predict_cleanup_time_ms() { | |
531 return get_new_prediction(_concurrent_mark_cleanup_times_ms); | |
532 } | |
533 | |
534 // Returns an estimate of the survival rate of the region at yg-age | |
535 // "yg_age". | |
545 | 536 double predict_yg_surv_rate(int age, SurvRateGroup* surv_rate_group) { |
537 TruncatedSeq* seq = surv_rate_group->get_seq(age); | |
342 | 538 if (seq->num() == 0) |
539 gclog_or_tty->print("BARF! age is %d", age); | |
540 guarantee( seq->num() > 0, "invariant" ); | |
541 double pred = get_new_prediction(seq); | |
542 if (pred > 1.0) | |
543 pred = 1.0; | |
544 return pred; | |
545 } | |
546 | |
545 | 547 double predict_yg_surv_rate(int age) { |
548 return predict_yg_surv_rate(age, _short_lived_surv_rate_group); | |
549 } | |
550 | |
342 | 551 double accum_yg_surv_rate_pred(int age) { |
552 return _short_lived_surv_rate_group->accum_surv_rate_pred(age); | |
553 } | |
554 | |
555 protected: | |
1611 | 556 void print_stats(int level, const char* str, double value); |
557 void print_stats(int level, const char* str, int value); | |
558 | |
2430 | 559 void print_par_stats(int level, const char* str, double* data); |
560 void print_par_sizes(int level, const char* str, double* data); | |
342 | 561 |
562 void check_other_times(int level, | |
563 NumberSeq* other_times_ms, | |
564 NumberSeq* calc_other_times_ms) const; | |
565 | |
566 void print_summary (PauseSummary* stats) const; | |
567 | |
568 void print_summary (int level, const char* str, NumberSeq* seq) const; | |
569 void print_summary_sd (int level, const char* str, NumberSeq* seq) const; | |
570 | |
571 double avg_value (double* data); | |
572 double max_value (double* data); | |
573 double sum_of_values (double* data); | |
574 double max_sum (double* data1, double* data2); | |
575 | |
576 int _last_satb_drain_processed_buffers; | |
577 int _last_update_rs_processed_buffers; | |
578 double _last_pause_time_ms; | |
579 | |
580 size_t _bytes_in_collection_set_before_gc; | |
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581 size_t _bytes_copied_during_gc; |
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582 |
342 | 583 // Used to count used bytes in CS. |
584 friend class CountCSClosure; | |
585 | |
586 // Statistics kept per GC stoppage, pause or full. | |
587 TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec; | |
588 | |
589 // We track markings. | |
590 int _num_markings; | |
591 double _mark_thread_startup_sec; // Time at startup of marking thread | |
592 | |
593 // Add a new GC of the given duration and end time to the record. | |
594 void update_recent_gc_times(double end_time_sec, double elapsed_ms); | |
595 | |
596 // The head of the list (via "next_in_collection_set()") representing the | |
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597 // current collection set. Set from the incrementally built collection |
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598 // set at the start of the pause. |
342 | 599 HeapRegion* _collection_set; |
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600 |
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601 // The number of regions in the collection set. Set from the incrementally |
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602 // built collection set at the start of an evacuation pause. |
342 | 603 size_t _collection_set_size; |
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604 |
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605 // The number of bytes in the collection set before the pause. Set from |
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606 // the incrementally built collection set at the start of an evacuation |
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607 // pause. |
342 | 608 size_t _collection_set_bytes_used_before; |
609 | |
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610 // The associated information that is maintained while the incremental |
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611 // collection set is being built with young regions. Used to populate |
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612 // the recorded info for the evacuation pause. |
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613 |
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614 enum CSetBuildType { |
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615 Active, // We are actively building the collection set |
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616 Inactive // We are not actively building the collection set |
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617 }; |
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618 |
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619 CSetBuildType _inc_cset_build_state; |
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620 |
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621 // The head of the incrementally built collection set. |
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622 HeapRegion* _inc_cset_head; |
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623 |
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624 // The tail of the incrementally built collection set. |
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625 HeapRegion* _inc_cset_tail; |
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626 |
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627 // The number of regions in the incrementally built collection set. |
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628 // Used to set _collection_set_size at the start of an evacuation |
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629 // pause. |
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630 size_t _inc_cset_size; |
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631 |
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632 // Used as the index in the surving young words structure |
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633 // which tracks the amount of space, for each young region, |
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634 // that survives the pause. |
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635 size_t _inc_cset_young_index; |
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636 |
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637 // The number of bytes in the incrementally built collection set. |
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638 // Used to set _collection_set_bytes_used_before at the start of |
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639 // an evacuation pause. |
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640 size_t _inc_cset_bytes_used_before; |
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641 |
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642 // Used to record the highest end of heap region in collection set |
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643 HeapWord* _inc_cset_max_finger; |
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644 |
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645 // The number of recorded used bytes in the young regions |
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646 // of the collection set. This is the sum of the used() bytes |
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647 // of retired young regions in the collection set. |
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648 size_t _inc_cset_recorded_young_bytes; |
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649 |
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650 // The RSet lengths recorded for regions in the collection set |
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651 // (updated by the periodic sampling of the regions in the |
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652 // young list/collection set). |
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653 size_t _inc_cset_recorded_rs_lengths; |
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654 |
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655 // The predicted elapsed time it will take to collect the regions |
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656 // in the collection set (updated by the periodic sampling of the |
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657 // regions in the young list/collection set). |
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658 double _inc_cset_predicted_elapsed_time_ms; |
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659 |
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660 // The predicted bytes to copy for the regions in the collection |
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661 // set (updated by the periodic sampling of the regions in the |
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662 // young list/collection set). |
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663 size_t _inc_cset_predicted_bytes_to_copy; |
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664 |
342 | 665 // Info about marking. |
666 int _n_marks; // Sticky at 2, so we know when we've done at least 2. | |
667 | |
668 // The number of collection pauses at the end of the last mark. | |
669 size_t _n_pauses_at_mark_end; | |
670 | |
671 // Stash a pointer to the g1 heap. | |
672 G1CollectedHeap* _g1; | |
673 | |
674 // The average time in ms per collection pause, averaged over recent pauses. | |
675 double recent_avg_time_for_pauses_ms(); | |
676 | |
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677 // The average time in ms for RS scanning, per pause, averaged |
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678 // over recent pauses. (Note the RS scanning time for a pause |
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679 // is itself an average of the RS scanning time for each worker |
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680 // thread.) |
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681 double recent_avg_time_for_rs_scan_ms(); |
342 | 682 |
683 // The number of "recent" GCs recorded in the number sequences | |
684 int number_of_recent_gcs(); | |
685 | |
686 // The average survival ratio, computed by the total number of bytes | |
687 // suriviving / total number of bytes before collection over the last | |
688 // several recent pauses. | |
689 double recent_avg_survival_fraction(); | |
690 // The survival fraction of the most recent pause; if there have been no | |
691 // pauses, returns 1.0. | |
692 double last_survival_fraction(); | |
693 | |
694 // Returns a "conservative" estimate of the recent survival rate, i.e., | |
695 // one that may be higher than "recent_avg_survival_fraction". | |
696 // This is conservative in several ways: | |
697 // If there have been few pauses, it will assume a potential high | |
698 // variance, and err on the side of caution. | |
699 // It puts a lower bound (currently 0.1) on the value it will return. | |
700 // To try to detect phase changes, if the most recent pause ("latest") has a | |
701 // higher-than average ("avg") survival rate, it returns that rate. | |
702 // "work" version is a utility function; young is restricted to young regions. | |
703 double conservative_avg_survival_fraction_work(double avg, | |
704 double latest); | |
705 | |
706 // The arguments are the two sequences that keep track of the number of bytes | |
707 // surviving and the total number of bytes before collection, resp., | |
708 // over the last evereal recent pauses | |
709 // Returns the survival rate for the category in the most recent pause. | |
710 // If there have been no pauses, returns 1.0. | |
711 double last_survival_fraction_work(TruncatedSeq* surviving, | |
712 TruncatedSeq* before); | |
713 | |
714 // The arguments are the two sequences that keep track of the number of bytes | |
715 // surviving and the total number of bytes before collection, resp., | |
716 // over the last several recent pauses | |
717 // Returns the average survival ration over the last several recent pauses | |
718 // If there have been no pauses, return 1.0 | |
719 double recent_avg_survival_fraction_work(TruncatedSeq* surviving, | |
720 TruncatedSeq* before); | |
721 | |
722 double conservative_avg_survival_fraction() { | |
723 double avg = recent_avg_survival_fraction(); | |
724 double latest = last_survival_fraction(); | |
725 return conservative_avg_survival_fraction_work(avg, latest); | |
726 } | |
727 | |
728 // The ratio of gc time to elapsed time, computed over recent pauses. | |
729 double _recent_avg_pause_time_ratio; | |
730 | |
731 double recent_avg_pause_time_ratio() { | |
732 return _recent_avg_pause_time_ratio; | |
733 } | |
734 | |
735 // Number of pauses between concurrent marking. | |
736 size_t _pauses_btwn_concurrent_mark; | |
737 | |
738 size_t _n_marks_since_last_pause; | |
739 | |
1359
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740 // At the end of a pause we check the heap occupancy and we decide |
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741 // whether we will start a marking cycle during the next pause. If |
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742 // we decide that we want to do that, we will set this parameter to |
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743 // true. So, this parameter will stay true between the end of a |
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744 // pause and the beginning of a subsequent pause (not necessarily |
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745 // the next one, see the comments on the next field) when we decide |
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746 // that we will indeed start a marking cycle and do the initial-mark |
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747 // work. |
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748 volatile bool _initiate_conc_mark_if_possible; |
342 | 749 |
1359
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750 // If initiate_conc_mark_if_possible() is set at the beginning of a |
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751 // pause, it is a suggestion that the pause should start a marking |
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752 // cycle by doing the initial-mark work. However, it is possible |
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753 // that the concurrent marking thread is still finishing up the |
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754 // previous marking cycle (e.g., clearing the next marking |
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755 // bitmap). If that is the case we cannot start a new cycle and |
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756 // we'll have to wait for the concurrent marking thread to finish |
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757 // what it is doing. In this case we will postpone the marking cycle |
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758 // initiation decision for the next pause. When we eventually decide |
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759 // to start a cycle, we will set _during_initial_mark_pause which |
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760 // will stay true until the end of the initial-mark pause and it's |
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761 // the condition that indicates that a pause is doing the |
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762 // initial-mark work. |
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763 volatile bool _during_initial_mark_pause; |
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764 |
342 | 765 bool _should_revert_to_full_young_gcs; |
766 bool _last_full_young_gc; | |
767 | |
768 // This set of variables tracks the collector efficiency, in order to | |
769 // determine whether we should initiate a new marking. | |
770 double _cur_mark_stop_world_time_ms; | |
771 double _mark_remark_start_sec; | |
772 double _mark_cleanup_start_sec; | |
773 double _mark_closure_time_ms; | |
774 | |
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775 // Update the young list target length either by setting it to the |
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776 // desired fixed value or by calculating it using G1's pause |
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777 // prediction model. If no rs_lengths parameter is passed, predict |
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778 // the RS lengths using the prediction model, otherwise use the |
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779 // given rs_lengths as the prediction. |
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780 void update_young_list_target_length(size_t rs_lengths = (size_t) -1); |
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781 |
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782 // Calculate and return the minimum desired young list target |
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783 // length. This is the minimum desired young list length according |
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784 // to the user's inputs. |
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785 size_t calculate_young_list_desired_min_length(size_t base_min_length); |
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786 |
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787 // Calculate and return the maximum desired young list target |
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788 // length. This is the maximum desired young list length according |
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789 // to the user's inputs. |
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790 size_t calculate_young_list_desired_max_length(); |
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791 |
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792 // Calculate and return the maximum young list target length that |
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793 // can fit into the pause time goal. The parameters are: rs_lengths |
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794 // represent the prediction of how large the young RSet lengths will |
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795 // be, base_min_length is the alreay existing number of regions in |
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796 // the young list, min_length and max_length are the desired min and |
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797 // max young list length according to the user's inputs. |
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798 size_t calculate_young_list_target_length(size_t rs_lengths, |
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799 size_t base_min_length, |
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800 size_t desired_min_length, |
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801 size_t desired_max_length); |
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802 |
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803 // Check whether a given young length (young_length) fits into the |
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804 // given target pause time and whether the prediction for the amount |
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805 // of objects to be copied for the given length will fit into the |
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806 // given free space (expressed by base_free_regions). It is used by |
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807 // calculate_young_list_target_length(). |
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808 bool predict_will_fit(size_t young_length, double base_time_ms, |
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809 size_t base_free_regions, double target_pause_time_ms); |
342 | 810 |
811 public: | |
812 | |
813 G1CollectorPolicy(); | |
814 | |
815 virtual G1CollectorPolicy* as_g1_policy() { return this; } | |
816 | |
817 virtual CollectorPolicy::Name kind() { | |
818 return CollectorPolicy::G1CollectorPolicyKind; | |
819 } | |
820 | |
3919
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821 // Check the current value of the young list RSet lengths and |
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822 // compare it against the last prediction. If the current value is |
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823 // higher, recalculate the young list target length prediction. |
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824 void revise_young_list_target_length_if_necessary(); |
342 | 825 |
826 size_t bytes_in_collection_set() { | |
827 return _bytes_in_collection_set_before_gc; | |
828 } | |
829 | |
830 unsigned calc_gc_alloc_time_stamp() { | |
831 return _all_pause_times_ms->num() + 1; | |
832 } | |
833 | |
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834 // This should be called after the heap is resized. |
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835 void record_new_heap_size(size_t new_number_of_regions); |
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836 |
342 | 837 protected: |
838 | |
839 // Count the number of bytes used in the CS. | |
840 void count_CS_bytes_used(); | |
841 | |
842 // Together these do the base cleanup-recording work. Subclasses might | |
843 // want to put something between them. | |
844 void record_concurrent_mark_cleanup_end_work1(size_t freed_bytes, | |
845 size_t max_live_bytes); | |
846 void record_concurrent_mark_cleanup_end_work2(); | |
847 | |
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848 void update_young_list_size_using_newratio(size_t number_of_heap_regions); |
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849 |
342 | 850 public: |
851 | |
852 virtual void init(); | |
853 | |
545 | 854 // Create jstat counters for the policy. |
855 virtual void initialize_gc_policy_counters(); | |
856 | |
342 | 857 virtual HeapWord* mem_allocate_work(size_t size, |
858 bool is_tlab, | |
859 bool* gc_overhead_limit_was_exceeded); | |
860 | |
861 // This method controls how a collector handles one or more | |
862 // of its generations being fully allocated. | |
863 virtual HeapWord* satisfy_failed_allocation(size_t size, | |
864 bool is_tlab); | |
865 | |
866 BarrierSet::Name barrier_set_name() { return BarrierSet::G1SATBCTLogging; } | |
867 | |
868 GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; } | |
869 | |
870 // The number of collection pauses so far. | |
871 long n_pauses() const { return _n_pauses; } | |
872 | |
873 // Update the heuristic info to record a collection pause of the given | |
874 // start time, where the given number of bytes were used at the start. | |
875 // This may involve changing the desired size of a collection set. | |
876 | |
877 virtual void record_stop_world_start(); | |
878 | |
879 virtual void record_collection_pause_start(double start_time_sec, | |
880 size_t start_used); | |
881 | |
882 // Must currently be called while the world is stopped. | |
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883 void record_concurrent_mark_init_end(double |
342 | 884 mark_init_elapsed_time_ms); |
885 | |
886 void record_mark_closure_time(double mark_closure_time_ms); | |
887 | |
888 virtual void record_concurrent_mark_remark_start(); | |
889 virtual void record_concurrent_mark_remark_end(); | |
890 | |
891 virtual void record_concurrent_mark_cleanup_start(); | |
892 virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes, | |
893 size_t max_live_bytes); | |
894 virtual void record_concurrent_mark_cleanup_completed(); | |
895 | |
896 virtual void record_concurrent_pause(); | |
897 virtual void record_concurrent_pause_end(); | |
898 | |
1707 | 899 virtual void record_collection_pause_end(); |
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900 void print_heap_transition(); |
342 | 901 |
902 // Record the fact that a full collection occurred. | |
903 virtual void record_full_collection_start(); | |
904 virtual void record_full_collection_end(); | |
905 | |
1611 | 906 void record_gc_worker_start_time(int worker_i, double ms) { |
907 _par_last_gc_worker_start_times_ms[worker_i] = ms; | |
908 } | |
909 | |
342 | 910 void record_ext_root_scan_time(int worker_i, double ms) { |
911 _par_last_ext_root_scan_times_ms[worker_i] = ms; | |
912 } | |
913 | |
914 void record_mark_stack_scan_time(int worker_i, double ms) { | |
915 _par_last_mark_stack_scan_times_ms[worker_i] = ms; | |
916 } | |
917 | |
918 void record_satb_drain_time(double ms) { | |
919 _cur_satb_drain_time_ms = ms; | |
920 _satb_drain_time_set = true; | |
921 } | |
922 | |
923 void record_satb_drain_processed_buffers (int processed_buffers) { | |
924 _last_satb_drain_processed_buffers = processed_buffers; | |
925 } | |
926 | |
927 void record_mod_union_time(double ms) { | |
928 _all_mod_union_times_ms->add(ms); | |
929 } | |
930 | |
931 void record_update_rs_time(int thread, double ms) { | |
932 _par_last_update_rs_times_ms[thread] = ms; | |
933 } | |
934 | |
935 void record_update_rs_processed_buffers (int thread, | |
936 double processed_buffers) { | |
937 _par_last_update_rs_processed_buffers[thread] = processed_buffers; | |
938 } | |
939 | |
940 void record_scan_rs_time(int thread, double ms) { | |
941 _par_last_scan_rs_times_ms[thread] = ms; | |
942 } | |
943 | |
944 void reset_obj_copy_time(int thread) { | |
945 _par_last_obj_copy_times_ms[thread] = 0.0; | |
946 } | |
947 | |
948 void reset_obj_copy_time() { | |
949 reset_obj_copy_time(0); | |
950 } | |
951 | |
952 void record_obj_copy_time(int thread, double ms) { | |
953 _par_last_obj_copy_times_ms[thread] += ms; | |
954 } | |
955 | |
1611 | 956 void record_termination(int thread, double ms, size_t attempts) { |
957 _par_last_termination_times_ms[thread] = ms; | |
958 _par_last_termination_attempts[thread] = (double) attempts; | |
342 | 959 } |
960 | |
1611 | 961 void record_gc_worker_end_time(int worker_i, double ms) { |
962 _par_last_gc_worker_end_times_ms[worker_i] = ms; | |
342 | 963 } |
964 | |
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965 void record_pause_time_ms(double ms) { |
342 | 966 _last_pause_time_ms = ms; |
967 } | |
968 | |
969 void record_clear_ct_time(double ms) { | |
970 _cur_clear_ct_time_ms = ms; | |
971 } | |
972 | |
973 void record_par_time(double ms) { | |
974 _cur_collection_par_time_ms = ms; | |
975 } | |
976 | |
977 void record_aux_start_time(int i) { | |
978 guarantee(i < _aux_num, "should be within range"); | |
979 _cur_aux_start_times_ms[i] = os::elapsedTime() * 1000.0; | |
980 } | |
981 | |
982 void record_aux_end_time(int i) { | |
983 guarantee(i < _aux_num, "should be within range"); | |
984 double ms = os::elapsedTime() * 1000.0 - _cur_aux_start_times_ms[i]; | |
985 _cur_aux_times_set[i] = true; | |
986 _cur_aux_times_ms[i] += ms; | |
987 } | |
988 | |
890
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989 #ifndef PRODUCT |
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990 void record_cc_clear_time(double ms) { |
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991 if (_min_clear_cc_time_ms < 0.0 || ms <= _min_clear_cc_time_ms) |
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992 _min_clear_cc_time_ms = ms; |
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993 if (_max_clear_cc_time_ms < 0.0 || ms >= _max_clear_cc_time_ms) |
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994 _max_clear_cc_time_ms = ms; |
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995 _cur_clear_cc_time_ms = ms; |
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996 _cum_clear_cc_time_ms += ms; |
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997 _num_cc_clears++; |
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998 } |
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999 #endif |
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1000 |
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1001 // Record how much space we copied during a GC. This is typically |
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1002 // called when a GC alloc region is being retired. |
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1003 void record_bytes_copied_during_gc(size_t bytes) { |
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1004 _bytes_copied_during_gc += bytes; |
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1005 } |
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1006 |
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1007 // The amount of space we copied during a GC. |
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1008 size_t bytes_copied_during_gc() { |
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1009 return _bytes_copied_during_gc; |
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1010 } |
342 | 1011 |
1012 // Choose a new collection set. Marks the chosen regions as being | |
1013 // "in_collection_set", and links them together. The head and number of | |
1014 // the collection set are available via access methods. | |
1707 | 1015 virtual void choose_collection_set(double target_pause_time_ms) = 0; |
342 | 1016 |
1017 // The head of the list (via "next_in_collection_set()") representing the | |
1018 // current collection set. | |
1019 HeapRegion* collection_set() { return _collection_set; } | |
1020 | |
1394
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1021 void clear_collection_set() { _collection_set = NULL; } |
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1022 |
342 | 1023 // The number of elements in the current collection set. |
1024 size_t collection_set_size() { return _collection_set_size; } | |
1025 | |
1026 // Add "hr" to the CS. | |
1027 void add_to_collection_set(HeapRegion* hr); | |
1028 | |
1394
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1029 // Incremental CSet Support |
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1030 |
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1031 // The head of the incrementally built collection set. |
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1032 HeapRegion* inc_cset_head() { return _inc_cset_head; } |
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1033 |
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1034 // The tail of the incrementally built collection set. |
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1035 HeapRegion* inc_set_tail() { return _inc_cset_tail; } |
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1036 |
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1037 // The number of elements in the incrementally built collection set. |
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1038 size_t inc_cset_size() { return _inc_cset_size; } |
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1039 |
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1040 // Initialize incremental collection set info. |
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1041 void start_incremental_cset_building(); |
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1042 |
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1043 void clear_incremental_cset() { |
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1044 _inc_cset_head = NULL; |
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1045 _inc_cset_tail = NULL; |
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1046 } |
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1047 |
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1048 // Stop adding regions to the incremental collection set |
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1049 void stop_incremental_cset_building() { _inc_cset_build_state = Inactive; } |
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1050 |
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1051 // Add/remove information about hr to the aggregated information |
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1052 // for the incrementally built collection set. |
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1053 void add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length); |
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1054 void remove_from_incremental_cset_info(HeapRegion* hr); |
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1055 |
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1056 // Update information about hr in the aggregated information for |
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1057 // the incrementally built collection set. |
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1058 void update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length); |
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1059 |
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1060 private: |
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1061 // Update the incremental cset information when adding a region |
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1062 // (should not be called directly). |
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1063 void add_region_to_incremental_cset_common(HeapRegion* hr); |
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1064 |
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1065 public: |
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1066 // Add hr to the LHS of the incremental collection set. |
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1067 void add_region_to_incremental_cset_lhs(HeapRegion* hr); |
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1068 |
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1069 // Add hr to the RHS of the incremental collection set. |
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1070 void add_region_to_incremental_cset_rhs(HeapRegion* hr); |
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1071 |
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1072 #ifndef PRODUCT |
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1073 void print_collection_set(HeapRegion* list_head, outputStream* st); |
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1074 #endif // !PRODUCT |
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1075 |
1359
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1076 bool initiate_conc_mark_if_possible() { return _initiate_conc_mark_if_possible; } |
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1077 void set_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = true; } |
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1078 void clear_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = false; } |
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1079 |
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1080 bool during_initial_mark_pause() { return _during_initial_mark_pause; } |
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1081 void set_during_initial_mark_pause() { _during_initial_mark_pause = true; } |
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1082 void clear_during_initial_mark_pause(){ _during_initial_mark_pause = false; } |
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1083 |
1656
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1084 // This sets the initiate_conc_mark_if_possible() flag to start a |
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1085 // new cycle, as long as we are not already in one. It's best if it |
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1086 // is called during a safepoint when the test whether a cycle is in |
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1087 // progress or not is stable. |
3914
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1088 bool force_initial_mark_if_outside_cycle(GCCause::Cause gc_cause); |
1656
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1089 |
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1090 // This is called at the very beginning of an evacuation pause (it |
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1091 // has to be the first thing that the pause does). If |
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1092 // initiate_conc_mark_if_possible() is true, and the concurrent |
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1093 // marking thread has completed its work during the previous cycle, |
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1094 // it will set during_initial_mark_pause() to so that the pause does |
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1095 // the initial-mark work and start a marking cycle. |
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1096 void decide_on_conc_mark_initiation(); |
342 | 1097 |
1098 // If an expansion would be appropriate, because recent GC overhead had | |
1099 // exceeded the desired limit, return an amount to expand by. | |
1100 virtual size_t expansion_amount(); | |
1101 | |
1102 // note start of mark thread | |
1103 void note_start_of_mark_thread(); | |
1104 | |
1105 // The marked bytes of the "r" has changed; reclassify it's desirability | |
1106 // for marking. Also asserts that "r" is eligible for a CS. | |
1107 virtual void note_change_in_marked_bytes(HeapRegion* r) = 0; | |
1108 | |
1109 #ifndef PRODUCT | |
1110 // Check any appropriate marked bytes info, asserting false if | |
1111 // something's wrong, else returning "true". | |
1112 virtual bool assertMarkedBytesDataOK() = 0; | |
1113 #endif | |
1114 | |
1115 // Print tracing information. | |
1116 void print_tracing_info() const; | |
1117 | |
1118 // Print stats on young survival ratio | |
1119 void print_yg_surv_rate_info() const; | |
1120 | |
545 | 1121 void finished_recalculating_age_indexes(bool is_survivors) { |
1122 if (is_survivors) { | |
1123 _survivor_surv_rate_group->finished_recalculating_age_indexes(); | |
1124 } else { | |
1125 _short_lived_surv_rate_group->finished_recalculating_age_indexes(); | |
1126 } | |
342 | 1127 // do that for any other surv rate groups |
1128 } | |
1129 | |
1973 | 1130 bool is_young_list_full() { |
1131 size_t young_list_length = _g1->young_list()->length(); | |
1991
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1132 size_t young_list_target_length = _young_list_target_length; |
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1133 return young_list_length >= young_list_target_length; |
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1134 } |
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1135 |
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1136 bool can_expand_young_list() { |
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1137 size_t young_list_length = _g1->young_list()->length(); |
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1138 size_t young_list_max_length = _young_list_max_length; |
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1139 return young_list_length < young_list_max_length; |
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1140 } |
1973 | 1141 |
1142 void update_region_num(bool young); | |
342 | 1143 |
1144 bool full_young_gcs() { | |
1145 return _full_young_gcs; | |
1146 } | |
1147 void set_full_young_gcs(bool full_young_gcs) { | |
1148 _full_young_gcs = full_young_gcs; | |
1149 } | |
1150 | |
1151 bool adaptive_young_list_length() { | |
1152 return _adaptive_young_list_length; | |
1153 } | |
1154 void set_adaptive_young_list_length(bool adaptive_young_list_length) { | |
1155 _adaptive_young_list_length = adaptive_young_list_length; | |
1156 } | |
1157 | |
1158 inline double get_gc_eff_factor() { | |
1159 double ratio = _known_garbage_ratio; | |
1160 | |
1161 double square = ratio * ratio; | |
1162 // square = square * square; | |
1163 double ret = square * 9.0 + 1.0; | |
1164 #if 0 | |
1165 gclog_or_tty->print_cr("ratio = %1.2lf, ret = %1.2lf", ratio, ret); | |
1166 #endif // 0 | |
1167 guarantee(0.0 <= ret && ret < 10.0, "invariant!"); | |
1168 return ret; | |
1169 } | |
1170 | |
1171 // | |
1172 // Survivor regions policy. | |
1173 // | |
1174 protected: | |
1175 | |
1176 // Current tenuring threshold, set to 0 if the collector reaches the | |
1177 // maximum amount of suvivors regions. | |
1178 int _tenuring_threshold; | |
1179 | |
545 | 1180 // The limit on the number of regions allocated for survivors. |
1181 size_t _max_survivor_regions; | |
1182 | |
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1183 // For reporting purposes. |
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1184 size_t _eden_bytes_before_gc; |
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1185 size_t _survivor_bytes_before_gc; |
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1186 size_t _capacity_before_gc; |
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1187 |
545 | 1188 // The amount of survor regions after a collection. |
1189 size_t _recorded_survivor_regions; | |
1190 // List of survivor regions. | |
1191 HeapRegion* _recorded_survivor_head; | |
1192 HeapRegion* _recorded_survivor_tail; | |
1193 | |
1194 ageTable _survivors_age_table; | |
1195 | |
342 | 1196 public: |
1197 | |
1198 inline GCAllocPurpose | |
1199 evacuation_destination(HeapRegion* src_region, int age, size_t word_sz) { | |
1200 if (age < _tenuring_threshold && src_region->is_young()) { | |
1201 return GCAllocForSurvived; | |
1202 } else { | |
1203 return GCAllocForTenured; | |
1204 } | |
1205 } | |
1206 | |
1207 inline bool track_object_age(GCAllocPurpose purpose) { | |
1208 return purpose == GCAllocForSurvived; | |
1209 } | |
1210 | |
545 | 1211 static const size_t REGIONS_UNLIMITED = ~(size_t)0; |
1212 | |
1213 size_t max_regions(int purpose); | |
342 | 1214 |
1215 // The limit on regions for a particular purpose is reached. | |
1216 void note_alloc_region_limit_reached(int purpose) { | |
1217 if (purpose == GCAllocForSurvived) { | |
1218 _tenuring_threshold = 0; | |
1219 } | |
1220 } | |
1221 | |
1222 void note_start_adding_survivor_regions() { | |
1223 _survivor_surv_rate_group->start_adding_regions(); | |
1224 } | |
1225 | |
1226 void note_stop_adding_survivor_regions() { | |
1227 _survivor_surv_rate_group->stop_adding_regions(); | |
1228 } | |
545 | 1229 |
1230 void record_survivor_regions(size_t regions, | |
1231 HeapRegion* head, | |
1232 HeapRegion* tail) { | |
1233 _recorded_survivor_regions = regions; | |
1234 _recorded_survivor_head = head; | |
1235 _recorded_survivor_tail = tail; | |
1236 } | |
1237 | |
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1238 size_t recorded_survivor_regions() { |
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1239 return _recorded_survivor_regions; |
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1240 } |
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1241 |
545 | 1242 void record_thread_age_table(ageTable* age_table) |
1243 { | |
1244 _survivors_age_table.merge_par(age_table); | |
1245 } | |
1246 | |
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1247 void update_max_gc_locker_expansion(); |
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1248 |
545 | 1249 // Calculates survivor space parameters. |
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1250 void update_survivors_policy(); |
545 | 1251 |
342 | 1252 }; |
1253 | |
1254 // This encapsulates a particular strategy for a g1 Collector. | |
1255 // | |
1256 // Start a concurrent mark when our heap size is n bytes | |
1257 // greater then our heap size was at the last concurrent | |
1258 // mark. Where n is a function of the CMSTriggerRatio | |
1259 // and the MinHeapFreeRatio. | |
1260 // | |
1261 // Start a g1 collection pause when we have allocated the | |
1262 // average number of bytes currently being freed in | |
1263 // a collection, but only if it is at least one region | |
1264 // full | |
1265 // | |
1266 // Resize Heap based on desired | |
1267 // allocation space, where desired allocation space is | |
1268 // a function of survival rate and desired future to size. | |
1269 // | |
1270 // Choose collection set by first picking all older regions | |
1271 // which have a survival rate which beats our projected young | |
1272 // survival rate. Then fill out the number of needed regions | |
1273 // with young regions. | |
1274 | |
1275 class G1CollectorPolicy_BestRegionsFirst: public G1CollectorPolicy { | |
1276 CollectionSetChooser* _collectionSetChooser; | |
1277 | |
1707 | 1278 virtual void choose_collection_set(double target_pause_time_ms); |
342 | 1279 virtual void record_collection_pause_start(double start_time_sec, |
1280 size_t start_used); | |
1281 virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes, | |
1282 size_t max_live_bytes); | |
1283 virtual void record_full_collection_end(); | |
1284 | |
1285 public: | |
1286 G1CollectorPolicy_BestRegionsFirst() { | |
1287 _collectionSetChooser = new CollectionSetChooser(); | |
1288 } | |
1707 | 1289 void record_collection_pause_end(); |
342 | 1290 // This is not needed any more, after the CSet choosing code was |
1291 // changed to use the pause prediction work. But let's leave the | |
1292 // hook in just in case. | |
1293 void note_change_in_marked_bytes(HeapRegion* r) { } | |
1294 #ifndef PRODUCT | |
1295 bool assertMarkedBytesDataOK(); | |
1296 #endif | |
1297 }; | |
1298 | |
1299 // This should move to some place more general... | |
1300 | |
1301 // If we have "n" measurements, and we've kept track of their "sum" and the | |
1302 // "sum_of_squares" of the measurements, this returns the variance of the | |
1303 // sequence. | |
1304 inline double variance(int n, double sum_of_squares, double sum) { | |
1305 double n_d = (double)n; | |
1306 double avg = sum/n_d; | |
1307 return (sum_of_squares - 2.0 * avg * sum + n_d * avg * avg) / n_d; | |
1308 } | |
1309 | |
1972 | 1310 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTORPOLICY_HPP |