Fri, 12 Jun 2009 16:20:16 -0400
6850846: G1: extend G1 marking verification
Summary: extend G1 marking verification to use either the "prev" or "next" marking information, as appropriate.
Reviewed-by: johnc, ysr
1 /*
2 * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 #include "incls/_precompiled.incl"
26 #include "incls/_g1CollectorPolicy.cpp.incl"
28 #define PREDICTIONS_VERBOSE 0
30 // <NEW PREDICTION>
32 // Different defaults for different number of GC threads
33 // They were chosen by running GCOld and SPECjbb on debris with different
34 // numbers of GC threads and choosing them based on the results
36 // all the same
37 static double rs_length_diff_defaults[] = {
38 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
39 };
41 static double cost_per_card_ms_defaults[] = {
42 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015
43 };
45 static double cost_per_scan_only_region_ms_defaults[] = {
46 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
47 };
49 // all the same
50 static double fully_young_cards_per_entry_ratio_defaults[] = {
51 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
52 };
54 static double cost_per_entry_ms_defaults[] = {
55 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005
56 };
58 static double cost_per_byte_ms_defaults[] = {
59 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009
60 };
62 // these should be pretty consistent
63 static double constant_other_time_ms_defaults[] = {
64 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0
65 };
68 static double young_other_cost_per_region_ms_defaults[] = {
69 0.3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1
70 };
72 static double non_young_other_cost_per_region_ms_defaults[] = {
73 1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30
74 };
76 // </NEW PREDICTION>
78 G1CollectorPolicy::G1CollectorPolicy() :
79 _parallel_gc_threads((ParallelGCThreads > 0) ? ParallelGCThreads : 1),
80 _n_pauses(0),
81 _recent_CH_strong_roots_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
82 _recent_G1_strong_roots_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
83 _recent_evac_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
84 _recent_pause_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
85 _recent_rs_sizes(new TruncatedSeq(NumPrevPausesForHeuristics)),
86 _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
87 _all_pause_times_ms(new NumberSeq()),
88 _stop_world_start(0.0),
89 _all_stop_world_times_ms(new NumberSeq()),
90 _all_yield_times_ms(new NumberSeq()),
92 _all_mod_union_times_ms(new NumberSeq()),
94 _summary(new Summary()),
95 _abandoned_summary(new AbandonedSummary()),
97 _cur_clear_ct_time_ms(0.0),
99 _region_num_young(0),
100 _region_num_tenured(0),
101 _prev_region_num_young(0),
102 _prev_region_num_tenured(0),
104 _aux_num(10),
105 _all_aux_times_ms(new NumberSeq[_aux_num]),
106 _cur_aux_start_times_ms(new double[_aux_num]),
107 _cur_aux_times_ms(new double[_aux_num]),
108 _cur_aux_times_set(new bool[_aux_num]),
110 _concurrent_mark_init_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
111 _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
112 _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
114 // <NEW PREDICTION>
116 _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
117 _prev_collection_pause_end_ms(0.0),
118 _pending_card_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
119 _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
120 _cost_per_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
121 _cost_per_scan_only_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
122 _fully_young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
123 _partially_young_cards_per_entry_ratio_seq(
124 new TruncatedSeq(TruncatedSeqLength)),
125 _cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
126 _partially_young_cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
127 _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
128 _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
129 _cost_per_scan_only_region_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
130 _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
131 _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
132 _non_young_other_cost_per_region_ms_seq(
133 new TruncatedSeq(TruncatedSeqLength)),
135 _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
136 _scanned_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
137 _rs_lengths_seq(new TruncatedSeq(TruncatedSeqLength)),
139 _pause_time_target_ms((double) MaxGCPauseMillis),
141 // </NEW PREDICTION>
143 _in_young_gc_mode(false),
144 _full_young_gcs(true),
145 _full_young_pause_num(0),
146 _partial_young_pause_num(0),
148 _during_marking(false),
149 _in_marking_window(false),
150 _in_marking_window_im(false),
152 _known_garbage_ratio(0.0),
153 _known_garbage_bytes(0),
155 _young_gc_eff_seq(new TruncatedSeq(TruncatedSeqLength)),
156 _target_pause_time_ms(-1.0),
158 _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)),
160 _recent_CS_bytes_used_before(new TruncatedSeq(NumPrevPausesForHeuristics)),
161 _recent_CS_bytes_surviving(new TruncatedSeq(NumPrevPausesForHeuristics)),
163 _recent_avg_pause_time_ratio(0.0),
164 _num_markings(0),
165 _n_marks(0),
166 _n_pauses_at_mark_end(0),
168 _all_full_gc_times_ms(new NumberSeq()),
170 // G1PausesBtwnConcMark defaults to -1
171 // so the hack is to do the cast QQQ FIXME
172 _pauses_btwn_concurrent_mark((size_t)G1PausesBtwnConcMark),
173 _n_marks_since_last_pause(0),
174 _conc_mark_initiated(false),
175 _should_initiate_conc_mark(false),
176 _should_revert_to_full_young_gcs(false),
177 _last_full_young_gc(false),
179 _prev_collection_pause_used_at_end_bytes(0),
181 _collection_set(NULL),
182 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
183 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
184 #endif // _MSC_VER
186 _short_lived_surv_rate_group(new SurvRateGroup(this, "Short Lived",
187 G1YoungSurvRateNumRegionsSummary)),
188 _survivor_surv_rate_group(new SurvRateGroup(this, "Survivor",
189 G1YoungSurvRateNumRegionsSummary)),
190 // add here any more surv rate groups
191 _recorded_survivor_regions(0),
192 _recorded_survivor_head(NULL),
193 _recorded_survivor_tail(NULL),
194 _survivors_age_table(true)
196 {
197 _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime());
198 _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0;
200 _par_last_ext_root_scan_times_ms = new double[_parallel_gc_threads];
201 _par_last_mark_stack_scan_times_ms = new double[_parallel_gc_threads];
202 _par_last_scan_only_times_ms = new double[_parallel_gc_threads];
203 _par_last_scan_only_regions_scanned = new double[_parallel_gc_threads];
205 _par_last_update_rs_start_times_ms = new double[_parallel_gc_threads];
206 _par_last_update_rs_times_ms = new double[_parallel_gc_threads];
207 _par_last_update_rs_processed_buffers = new double[_parallel_gc_threads];
209 _par_last_scan_rs_start_times_ms = new double[_parallel_gc_threads];
210 _par_last_scan_rs_times_ms = new double[_parallel_gc_threads];
211 _par_last_scan_new_refs_times_ms = new double[_parallel_gc_threads];
213 _par_last_obj_copy_times_ms = new double[_parallel_gc_threads];
215 _par_last_termination_times_ms = new double[_parallel_gc_threads];
217 // start conservatively
218 _expensive_region_limit_ms = 0.5 * (double) MaxGCPauseMillis;
220 // <NEW PREDICTION>
222 int index;
223 if (ParallelGCThreads == 0)
224 index = 0;
225 else if (ParallelGCThreads > 8)
226 index = 7;
227 else
228 index = ParallelGCThreads - 1;
230 _pending_card_diff_seq->add(0.0);
231 _rs_length_diff_seq->add(rs_length_diff_defaults[index]);
232 _cost_per_card_ms_seq->add(cost_per_card_ms_defaults[index]);
233 _cost_per_scan_only_region_ms_seq->add(
234 cost_per_scan_only_region_ms_defaults[index]);
235 _fully_young_cards_per_entry_ratio_seq->add(
236 fully_young_cards_per_entry_ratio_defaults[index]);
237 _cost_per_entry_ms_seq->add(cost_per_entry_ms_defaults[index]);
238 _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]);
239 _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]);
240 _young_other_cost_per_region_ms_seq->add(
241 young_other_cost_per_region_ms_defaults[index]);
242 _non_young_other_cost_per_region_ms_seq->add(
243 non_young_other_cost_per_region_ms_defaults[index]);
245 // </NEW PREDICTION>
247 double time_slice = (double) GCPauseIntervalMillis / 1000.0;
248 double max_gc_time = (double) MaxGCPauseMillis / 1000.0;
249 guarantee(max_gc_time < time_slice,
250 "Max GC time should not be greater than the time slice");
251 _mmu_tracker = new G1MMUTrackerQueue(time_slice, max_gc_time);
252 _sigma = (double) G1ConfidencePercent / 100.0;
254 // start conservatively (around 50ms is about right)
255 _concurrent_mark_init_times_ms->add(0.05);
256 _concurrent_mark_remark_times_ms->add(0.05);
257 _concurrent_mark_cleanup_times_ms->add(0.20);
258 _tenuring_threshold = MaxTenuringThreshold;
260 if (G1UseSurvivorSpaces) {
261 // if G1FixedSurvivorSpaceSize is 0 which means the size is not
262 // fixed, then _max_survivor_regions will be calculated at
263 // calculate_young_list_target_config during initialization
264 _max_survivor_regions = G1FixedSurvivorSpaceSize / HeapRegion::GrainBytes;
265 } else {
266 _max_survivor_regions = 0;
267 }
269 initialize_all();
270 }
272 // Increment "i", mod "len"
273 static void inc_mod(int& i, int len) {
274 i++; if (i == len) i = 0;
275 }
277 void G1CollectorPolicy::initialize_flags() {
278 set_min_alignment(HeapRegion::GrainBytes);
279 set_max_alignment(GenRemSet::max_alignment_constraint(rem_set_name()));
280 if (SurvivorRatio < 1) {
281 vm_exit_during_initialization("Invalid survivor ratio specified");
282 }
283 CollectorPolicy::initialize_flags();
284 }
286 void G1CollectorPolicy::init() {
287 // Set aside an initial future to_space.
288 _g1 = G1CollectedHeap::heap();
289 size_t regions = Universe::heap()->capacity() / HeapRegion::GrainBytes;
291 assert(Heap_lock->owned_by_self(), "Locking discipline.");
293 if (G1SteadyStateUsed < 50) {
294 vm_exit_during_initialization("G1SteadyStateUsed must be at least 50%.");
295 }
296 if (UseConcMarkSweepGC) {
297 vm_exit_during_initialization("-XX:+UseG1GC is incompatible with "
298 "-XX:+UseConcMarkSweepGC.");
299 }
301 initialize_gc_policy_counters();
303 if (G1Gen) {
304 _in_young_gc_mode = true;
306 if (G1YoungGenSize == 0) {
307 set_adaptive_young_list_length(true);
308 _young_list_fixed_length = 0;
309 } else {
310 set_adaptive_young_list_length(false);
311 _young_list_fixed_length = (G1YoungGenSize / HeapRegion::GrainBytes);
312 }
313 _free_regions_at_end_of_collection = _g1->free_regions();
314 _scan_only_regions_at_end_of_collection = 0;
315 calculate_young_list_min_length();
316 guarantee( _young_list_min_length == 0, "invariant, not enough info" );
317 calculate_young_list_target_config();
318 } else {
319 _young_list_fixed_length = 0;
320 _in_young_gc_mode = false;
321 }
322 }
324 // Create the jstat counters for the policy.
325 void G1CollectorPolicy::initialize_gc_policy_counters()
326 {
327 _gc_policy_counters = new GCPolicyCounters("GarbageFirst", 1, 2 + G1Gen);
328 }
330 void G1CollectorPolicy::calculate_young_list_min_length() {
331 _young_list_min_length = 0;
333 if (!adaptive_young_list_length())
334 return;
336 if (_alloc_rate_ms_seq->num() > 3) {
337 double now_sec = os::elapsedTime();
338 double when_ms = _mmu_tracker->when_max_gc_sec(now_sec) * 1000.0;
339 double alloc_rate_ms = predict_alloc_rate_ms();
340 int min_regions = (int) ceil(alloc_rate_ms * when_ms);
341 int current_region_num = (int) _g1->young_list_length();
342 _young_list_min_length = min_regions + current_region_num;
343 }
344 }
346 void G1CollectorPolicy::calculate_young_list_target_config() {
347 if (adaptive_young_list_length()) {
348 size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
349 calculate_young_list_target_config(rs_lengths);
350 } else {
351 if (full_young_gcs())
352 _young_list_target_length = _young_list_fixed_length;
353 else
354 _young_list_target_length = _young_list_fixed_length / 2;
355 _young_list_target_length = MAX2(_young_list_target_length, (size_t)1);
356 size_t so_length = calculate_optimal_so_length(_young_list_target_length);
357 guarantee( so_length < _young_list_target_length, "invariant" );
358 _young_list_so_prefix_length = so_length;
359 }
360 calculate_survivors_policy();
361 }
363 // This method calculate the optimal scan-only set for a fixed young
364 // gen size. I couldn't work out how to reuse the more elaborate one,
365 // i.e. calculate_young_list_target_config(rs_length), as the loops are
366 // fundamentally different (the other one finds a config for different
367 // S-O lengths, whereas here we need to do the opposite).
368 size_t G1CollectorPolicy::calculate_optimal_so_length(
369 size_t young_list_length) {
370 if (!G1UseScanOnlyPrefix)
371 return 0;
373 if (_all_pause_times_ms->num() < 3) {
374 // we won't use a scan-only set at the beginning to allow the rest
375 // of the predictors to warm up
376 return 0;
377 }
379 if (_cost_per_scan_only_region_ms_seq->num() < 3) {
380 // then, we'll only set the S-O set to 1 for a little bit of time,
381 // to get enough information on the scanning cost
382 return 1;
383 }
385 size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
386 size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
387 size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
388 size_t scanned_cards;
389 if (full_young_gcs())
390 scanned_cards = predict_young_card_num(adj_rs_lengths);
391 else
392 scanned_cards = predict_non_young_card_num(adj_rs_lengths);
393 double base_time_ms = predict_base_elapsed_time_ms(pending_cards,
394 scanned_cards);
396 size_t so_length = 0;
397 double max_gc_eff = 0.0;
398 for (size_t i = 0; i < young_list_length; ++i) {
399 double gc_eff = 0.0;
400 double pause_time_ms = 0.0;
401 predict_gc_eff(young_list_length, i, base_time_ms,
402 &gc_eff, &pause_time_ms);
403 if (gc_eff > max_gc_eff) {
404 max_gc_eff = gc_eff;
405 so_length = i;
406 }
407 }
409 // set it to 95% of the optimal to make sure we sample the "area"
410 // around the optimal length to get up-to-date survival rate data
411 return so_length * 950 / 1000;
412 }
414 // This is a really cool piece of code! It finds the best
415 // target configuration (young length / scan-only prefix length) so
416 // that GC efficiency is maximized and that we also meet a pause
417 // time. It's a triple nested loop. These loops are explained below
418 // from the inside-out :-)
419 //
420 // (a) The innermost loop will try to find the optimal young length
421 // for a fixed S-O length. It uses a binary search to speed up the
422 // process. We assume that, for a fixed S-O length, as we add more
423 // young regions to the CSet, the GC efficiency will only go up (I'll
424 // skip the proof). So, using a binary search to optimize this process
425 // makes perfect sense.
426 //
427 // (b) The middle loop will fix the S-O length before calling the
428 // innermost one. It will vary it between two parameters, increasing
429 // it by a given increment.
430 //
431 // (c) The outermost loop will call the middle loop three times.
432 // (1) The first time it will explore all possible S-O length values
433 // from 0 to as large as it can get, using a coarse increment (to
434 // quickly "home in" to where the optimal seems to be).
435 // (2) The second time it will explore the values around the optimal
436 // that was found by the first iteration using a fine increment.
437 // (3) Once the optimal config has been determined by the second
438 // iteration, we'll redo the calculation, but setting the S-O length
439 // to 95% of the optimal to make sure we sample the "area"
440 // around the optimal length to get up-to-date survival rate data
441 //
442 // Termination conditions for the iterations are several: the pause
443 // time is over the limit, we do not have enough to-space, etc.
445 void G1CollectorPolicy::calculate_young_list_target_config(size_t rs_lengths) {
446 guarantee( adaptive_young_list_length(), "pre-condition" );
448 double start_time_sec = os::elapsedTime();
449 size_t min_reserve_perc = MAX2((size_t)2, (size_t)G1MinReservePercent);
450 min_reserve_perc = MIN2((size_t) 50, min_reserve_perc);
451 size_t reserve_regions =
452 (size_t) ((double) min_reserve_perc * (double) _g1->n_regions() / 100.0);
454 if (full_young_gcs() && _free_regions_at_end_of_collection > 0) {
455 // we are in fully-young mode and there are free regions in the heap
457 double survivor_regions_evac_time =
458 predict_survivor_regions_evac_time();
460 size_t min_so_length = 0;
461 size_t max_so_length = 0;
463 if (G1UseScanOnlyPrefix) {
464 if (_all_pause_times_ms->num() < 3) {
465 // we won't use a scan-only set at the beginning to allow the rest
466 // of the predictors to warm up
467 min_so_length = 0;
468 max_so_length = 0;
469 } else if (_cost_per_scan_only_region_ms_seq->num() < 3) {
470 // then, we'll only set the S-O set to 1 for a little bit of time,
471 // to get enough information on the scanning cost
472 min_so_length = 1;
473 max_so_length = 1;
474 } else if (_in_marking_window || _last_full_young_gc) {
475 // no S-O prefix during a marking phase either, as at the end
476 // of the marking phase we'll have to use a very small young
477 // length target to fill up the rest of the CSet with
478 // non-young regions and, if we have lots of scan-only regions
479 // left-over, we will not be able to add any more non-young
480 // regions.
481 min_so_length = 0;
482 max_so_length = 0;
483 } else {
484 // this is the common case; we'll never reach the maximum, we
485 // one of the end conditions will fire well before that
486 // (hopefully!)
487 min_so_length = 0;
488 max_so_length = _free_regions_at_end_of_collection - 1;
489 }
490 } else {
491 // no S-O prefix, as the switch is not set, but we still need to
492 // do one iteration to calculate the best young target that
493 // meets the pause time; this way we reuse the same code instead
494 // of replicating it
495 min_so_length = 0;
496 max_so_length = 0;
497 }
499 double target_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
500 size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
501 size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
502 size_t scanned_cards;
503 if (full_young_gcs())
504 scanned_cards = predict_young_card_num(adj_rs_lengths);
505 else
506 scanned_cards = predict_non_young_card_num(adj_rs_lengths);
507 // calculate this once, so that we don't have to recalculate it in
508 // the innermost loop
509 double base_time_ms = predict_base_elapsed_time_ms(pending_cards, scanned_cards)
510 + survivor_regions_evac_time;
511 // the result
512 size_t final_young_length = 0;
513 size_t final_so_length = 0;
514 double final_gc_eff = 0.0;
515 // we'll also keep track of how many times we go into the inner loop
516 // this is for profiling reasons
517 size_t calculations = 0;
519 // this determines which of the three iterations the outer loop is in
520 typedef enum {
521 pass_type_coarse,
522 pass_type_fine,
523 pass_type_final
524 } pass_type_t;
526 // range of the outer loop's iteration
527 size_t from_so_length = min_so_length;
528 size_t to_so_length = max_so_length;
529 guarantee( from_so_length <= to_so_length, "invariant" );
531 // this will keep the S-O length that's found by the second
532 // iteration of the outer loop; we'll keep it just in case the third
533 // iteration fails to find something
534 size_t fine_so_length = 0;
536 // the increment step for the coarse (first) iteration
537 size_t so_coarse_increments = 5;
539 // the common case, we'll start with the coarse iteration
540 pass_type_t pass = pass_type_coarse;
541 size_t so_length_incr = so_coarse_increments;
543 if (from_so_length == to_so_length) {
544 // not point in doing the coarse iteration, we'll go directly into
545 // the fine one (we essentially trying to find the optimal young
546 // length for a fixed S-O length).
547 so_length_incr = 1;
548 pass = pass_type_final;
549 } else if (to_so_length - from_so_length < 3 * so_coarse_increments) {
550 // again, the range is too short so no point in foind the coarse
551 // iteration either
552 so_length_incr = 1;
553 pass = pass_type_fine;
554 }
556 bool done = false;
557 // this is the outermost loop
558 while (!done) {
559 #ifdef TRACE_CALC_YOUNG_CONFIG
560 // leave this in for debugging, just in case
561 gclog_or_tty->print_cr("searching between " SIZE_FORMAT " and " SIZE_FORMAT
562 ", incr " SIZE_FORMAT ", pass %s",
563 from_so_length, to_so_length, so_length_incr,
564 (pass == pass_type_coarse) ? "coarse" :
565 (pass == pass_type_fine) ? "fine" : "final");
566 #endif // TRACE_CALC_YOUNG_CONFIG
568 size_t so_length = from_so_length;
569 size_t init_free_regions =
570 MAX2((size_t)0,
571 _free_regions_at_end_of_collection +
572 _scan_only_regions_at_end_of_collection - reserve_regions);
574 // this determines whether a configuration was found
575 bool gc_eff_set = false;
576 // this is the middle loop
577 while (so_length <= to_so_length) {
578 // base time, which excludes region-related time; again we
579 // calculate it once to avoid recalculating it in the
580 // innermost loop
581 double base_time_with_so_ms =
582 base_time_ms + predict_scan_only_time_ms(so_length);
583 // it's already over the pause target, go around
584 if (base_time_with_so_ms > target_pause_time_ms)
585 break;
587 size_t starting_young_length = so_length+1;
589 // we make sure that the short young length that makes sense
590 // (one more than the S-O length) is feasible
591 size_t min_young_length = starting_young_length;
592 double min_gc_eff;
593 bool min_ok;
594 ++calculations;
595 min_ok = predict_gc_eff(min_young_length, so_length,
596 base_time_with_so_ms,
597 init_free_regions, target_pause_time_ms,
598 &min_gc_eff);
600 if (min_ok) {
601 // the shortest young length is indeed feasible; we'll know
602 // set up the max young length and we'll do a binary search
603 // between min_young_length and max_young_length
604 size_t max_young_length = _free_regions_at_end_of_collection - 1;
605 double max_gc_eff = 0.0;
606 bool max_ok = false;
608 // the innermost loop! (finally!)
609 while (max_young_length > min_young_length) {
610 // we'll make sure that min_young_length is always at a
611 // feasible config
612 guarantee( min_ok, "invariant" );
614 ++calculations;
615 max_ok = predict_gc_eff(max_young_length, so_length,
616 base_time_with_so_ms,
617 init_free_regions, target_pause_time_ms,
618 &max_gc_eff);
620 size_t diff = (max_young_length - min_young_length) / 2;
621 if (max_ok) {
622 min_young_length = max_young_length;
623 min_gc_eff = max_gc_eff;
624 min_ok = true;
625 }
626 max_young_length = min_young_length + diff;
627 }
629 // the innermost loop found a config
630 guarantee( min_ok, "invariant" );
631 if (min_gc_eff > final_gc_eff) {
632 // it's the best config so far, so we'll keep it
633 final_gc_eff = min_gc_eff;
634 final_young_length = min_young_length;
635 final_so_length = so_length;
636 gc_eff_set = true;
637 }
638 }
640 // incremental the fixed S-O length and go around
641 so_length += so_length_incr;
642 }
644 // this is the end of the outermost loop and we need to decide
645 // what to do during the next iteration
646 if (pass == pass_type_coarse) {
647 // we just did the coarse pass (first iteration)
649 if (!gc_eff_set)
650 // we didn't find a feasible config so we'll just bail out; of
651 // course, it might be the case that we missed it; but I'd say
652 // it's a bit unlikely
653 done = true;
654 else {
655 // We did find a feasible config with optimal GC eff during
656 // the first pass. So the second pass we'll only consider the
657 // S-O lengths around that config with a fine increment.
659 guarantee( so_length_incr == so_coarse_increments, "invariant" );
660 guarantee( final_so_length >= min_so_length, "invariant" );
662 #ifdef TRACE_CALC_YOUNG_CONFIG
663 // leave this in for debugging, just in case
664 gclog_or_tty->print_cr(" coarse pass: SO length " SIZE_FORMAT,
665 final_so_length);
666 #endif // TRACE_CALC_YOUNG_CONFIG
668 from_so_length =
669 (final_so_length - min_so_length > so_coarse_increments) ?
670 final_so_length - so_coarse_increments + 1 : min_so_length;
671 to_so_length =
672 (max_so_length - final_so_length > so_coarse_increments) ?
673 final_so_length + so_coarse_increments - 1 : max_so_length;
675 pass = pass_type_fine;
676 so_length_incr = 1;
677 }
678 } else if (pass == pass_type_fine) {
679 // we just finished the second pass
681 if (!gc_eff_set) {
682 // we didn't find a feasible config (yes, it's possible;
683 // notice that, sometimes, we go directly into the fine
684 // iteration and skip the coarse one) so we bail out
685 done = true;
686 } else {
687 // We did find a feasible config with optimal GC eff
688 guarantee( so_length_incr == 1, "invariant" );
690 if (final_so_length == 0) {
691 // The config is of an empty S-O set, so we'll just bail out
692 done = true;
693 } else {
694 // we'll go around once more, setting the S-O length to 95%
695 // of the optimal
696 size_t new_so_length = 950 * final_so_length / 1000;
698 #ifdef TRACE_CALC_YOUNG_CONFIG
699 // leave this in for debugging, just in case
700 gclog_or_tty->print_cr(" fine pass: SO length " SIZE_FORMAT
701 ", setting it to " SIZE_FORMAT,
702 final_so_length, new_so_length);
703 #endif // TRACE_CALC_YOUNG_CONFIG
705 from_so_length = new_so_length;
706 to_so_length = new_so_length;
707 fine_so_length = final_so_length;
709 pass = pass_type_final;
710 }
711 }
712 } else if (pass == pass_type_final) {
713 // we just finished the final (third) pass
715 if (!gc_eff_set)
716 // we didn't find a feasible config, so we'll just use the one
717 // we found during the second pass, which we saved
718 final_so_length = fine_so_length;
720 // and we're done!
721 done = true;
722 } else {
723 guarantee( false, "should never reach here" );
724 }
726 // we now go around the outermost loop
727 }
729 // we should have at least one region in the target young length
730 _young_list_target_length =
731 MAX2((size_t) 1, final_young_length + _recorded_survivor_regions);
732 if (final_so_length >= final_young_length)
733 // and we need to ensure that the S-O length is not greater than
734 // the target young length (this is being a bit careful)
735 final_so_length = 0;
736 _young_list_so_prefix_length = final_so_length;
737 guarantee( !_in_marking_window || !_last_full_young_gc ||
738 _young_list_so_prefix_length == 0, "invariant" );
740 // let's keep an eye of how long we spend on this calculation
741 // right now, I assume that we'll print it when we need it; we
742 // should really adde it to the breakdown of a pause
743 double end_time_sec = os::elapsedTime();
744 double elapsed_time_ms = (end_time_sec - start_time_sec) * 1000.0;
746 #ifdef TRACE_CALC_YOUNG_CONFIG
747 // leave this in for debugging, just in case
748 gclog_or_tty->print_cr("target = %1.1lf ms, young = " SIZE_FORMAT
749 ", SO = " SIZE_FORMAT ", "
750 "elapsed %1.2lf ms, calcs: " SIZE_FORMAT " (%s%s) "
751 SIZE_FORMAT SIZE_FORMAT,
752 target_pause_time_ms,
753 _young_list_target_length - _young_list_so_prefix_length,
754 _young_list_so_prefix_length,
755 elapsed_time_ms,
756 calculations,
757 full_young_gcs() ? "full" : "partial",
758 should_initiate_conc_mark() ? " i-m" : "",
759 _in_marking_window,
760 _in_marking_window_im);
761 #endif // TRACE_CALC_YOUNG_CONFIG
763 if (_young_list_target_length < _young_list_min_length) {
764 // bummer; this means that, if we do a pause when the optimal
765 // config dictates, we'll violate the pause spacing target (the
766 // min length was calculate based on the application's current
767 // alloc rate);
769 // so, we have to bite the bullet, and allocate the minimum
770 // number. We'll violate our target, but we just can't meet it.
772 size_t so_length = 0;
773 // a note further up explains why we do not want an S-O length
774 // during marking
775 if (!_in_marking_window && !_last_full_young_gc)
776 // but we can still try to see whether we can find an optimal
777 // S-O length
778 so_length = calculate_optimal_so_length(_young_list_min_length);
780 #ifdef TRACE_CALC_YOUNG_CONFIG
781 // leave this in for debugging, just in case
782 gclog_or_tty->print_cr("adjusted target length from "
783 SIZE_FORMAT " to " SIZE_FORMAT
784 ", SO " SIZE_FORMAT,
785 _young_list_target_length, _young_list_min_length,
786 so_length);
787 #endif // TRACE_CALC_YOUNG_CONFIG
789 _young_list_target_length =
790 MAX2(_young_list_min_length, (size_t)1);
791 _young_list_so_prefix_length = so_length;
792 }
793 } else {
794 // we are in a partially-young mode or we've run out of regions (due
795 // to evacuation failure)
797 #ifdef TRACE_CALC_YOUNG_CONFIG
798 // leave this in for debugging, just in case
799 gclog_or_tty->print_cr("(partial) setting target to " SIZE_FORMAT
800 ", SO " SIZE_FORMAT,
801 _young_list_min_length, 0);
802 #endif // TRACE_CALC_YOUNG_CONFIG
804 // we'll do the pause as soon as possible and with no S-O prefix
805 // (see above for the reasons behind the latter)
806 _young_list_target_length =
807 MAX2(_young_list_min_length, (size_t) 1);
808 _young_list_so_prefix_length = 0;
809 }
811 _rs_lengths_prediction = rs_lengths;
812 }
814 // This is used by: calculate_optimal_so_length(length). It returns
815 // the GC eff and predicted pause time for a particular config
816 void
817 G1CollectorPolicy::predict_gc_eff(size_t young_length,
818 size_t so_length,
819 double base_time_ms,
820 double* ret_gc_eff,
821 double* ret_pause_time_ms) {
822 double so_time_ms = predict_scan_only_time_ms(so_length);
823 double accum_surv_rate_adj = 0.0;
824 if (so_length > 0)
825 accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1));
826 double accum_surv_rate =
827 accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj;
828 size_t bytes_to_copy =
829 (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
830 double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
831 double young_other_time_ms =
832 predict_young_other_time_ms(young_length - so_length);
833 double pause_time_ms =
834 base_time_ms + so_time_ms + copy_time_ms + young_other_time_ms;
835 size_t reclaimed_bytes =
836 (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy;
837 double gc_eff = (double) reclaimed_bytes / pause_time_ms;
839 *ret_gc_eff = gc_eff;
840 *ret_pause_time_ms = pause_time_ms;
841 }
843 // This is used by: calculate_young_list_target_config(rs_length). It
844 // returns the GC eff of a particular config. It returns false if that
845 // config violates any of the end conditions of the search in the
846 // calling method, or true upon success. The end conditions were put
847 // here since it's called twice and it was best not to replicate them
848 // in the caller. Also, passing the parameteres avoids having to
849 // recalculate them in the innermost loop.
850 bool
851 G1CollectorPolicy::predict_gc_eff(size_t young_length,
852 size_t so_length,
853 double base_time_with_so_ms,
854 size_t init_free_regions,
855 double target_pause_time_ms,
856 double* ret_gc_eff) {
857 *ret_gc_eff = 0.0;
859 if (young_length >= init_free_regions)
860 // end condition 1: not enough space for the young regions
861 return false;
863 double accum_surv_rate_adj = 0.0;
864 if (so_length > 0)
865 accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1));
866 double accum_surv_rate =
867 accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj;
868 size_t bytes_to_copy =
869 (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
870 double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
871 double young_other_time_ms =
872 predict_young_other_time_ms(young_length - so_length);
873 double pause_time_ms =
874 base_time_with_so_ms + copy_time_ms + young_other_time_ms;
876 if (pause_time_ms > target_pause_time_ms)
877 // end condition 2: over the target pause time
878 return false;
880 size_t reclaimed_bytes =
881 (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy;
882 size_t free_bytes =
883 (init_free_regions - young_length) * HeapRegion::GrainBytes;
885 if ((2.0 + sigma()) * (double) bytes_to_copy > (double) free_bytes)
886 // end condition 3: out of to-space (conservatively)
887 return false;
889 // success!
890 double gc_eff = (double) reclaimed_bytes / pause_time_ms;
891 *ret_gc_eff = gc_eff;
893 return true;
894 }
896 double G1CollectorPolicy::predict_survivor_regions_evac_time() {
897 double survivor_regions_evac_time = 0.0;
898 for (HeapRegion * r = _recorded_survivor_head;
899 r != NULL && r != _recorded_survivor_tail->get_next_young_region();
900 r = r->get_next_young_region()) {
901 survivor_regions_evac_time += predict_region_elapsed_time_ms(r, true);
902 }
903 return survivor_regions_evac_time;
904 }
906 void G1CollectorPolicy::check_prediction_validity() {
907 guarantee( adaptive_young_list_length(), "should not call this otherwise" );
909 size_t rs_lengths = _g1->young_list_sampled_rs_lengths();
910 if (rs_lengths > _rs_lengths_prediction) {
911 // add 10% to avoid having to recalculate often
912 size_t rs_lengths_prediction = rs_lengths * 1100 / 1000;
913 calculate_young_list_target_config(rs_lengths_prediction);
914 }
915 }
917 HeapWord* G1CollectorPolicy::mem_allocate_work(size_t size,
918 bool is_tlab,
919 bool* gc_overhead_limit_was_exceeded) {
920 guarantee(false, "Not using this policy feature yet.");
921 return NULL;
922 }
924 // This method controls how a collector handles one or more
925 // of its generations being fully allocated.
926 HeapWord* G1CollectorPolicy::satisfy_failed_allocation(size_t size,
927 bool is_tlab) {
928 guarantee(false, "Not using this policy feature yet.");
929 return NULL;
930 }
933 #ifndef PRODUCT
934 bool G1CollectorPolicy::verify_young_ages() {
935 HeapRegion* head = _g1->young_list_first_region();
936 return
937 verify_young_ages(head, _short_lived_surv_rate_group);
938 // also call verify_young_ages on any additional surv rate groups
939 }
941 bool
942 G1CollectorPolicy::verify_young_ages(HeapRegion* head,
943 SurvRateGroup *surv_rate_group) {
944 guarantee( surv_rate_group != NULL, "pre-condition" );
946 const char* name = surv_rate_group->name();
947 bool ret = true;
948 int prev_age = -1;
950 for (HeapRegion* curr = head;
951 curr != NULL;
952 curr = curr->get_next_young_region()) {
953 SurvRateGroup* group = curr->surv_rate_group();
954 if (group == NULL && !curr->is_survivor()) {
955 gclog_or_tty->print_cr("## %s: encountered NULL surv_rate_group", name);
956 ret = false;
957 }
959 if (surv_rate_group == group) {
960 int age = curr->age_in_surv_rate_group();
962 if (age < 0) {
963 gclog_or_tty->print_cr("## %s: encountered negative age", name);
964 ret = false;
965 }
967 if (age <= prev_age) {
968 gclog_or_tty->print_cr("## %s: region ages are not strictly increasing "
969 "(%d, %d)", name, age, prev_age);
970 ret = false;
971 }
972 prev_age = age;
973 }
974 }
976 return ret;
977 }
978 #endif // PRODUCT
980 void G1CollectorPolicy::record_full_collection_start() {
981 _cur_collection_start_sec = os::elapsedTime();
982 // Release the future to-space so that it is available for compaction into.
983 _g1->set_full_collection();
984 }
986 void G1CollectorPolicy::record_full_collection_end() {
987 // Consider this like a collection pause for the purposes of allocation
988 // since last pause.
989 double end_sec = os::elapsedTime();
990 double full_gc_time_sec = end_sec - _cur_collection_start_sec;
991 double full_gc_time_ms = full_gc_time_sec * 1000.0;
993 checkpoint_conc_overhead();
995 _all_full_gc_times_ms->add(full_gc_time_ms);
997 update_recent_gc_times(end_sec, full_gc_time_ms);
999 _g1->clear_full_collection();
1001 // "Nuke" the heuristics that control the fully/partially young GC
1002 // transitions and make sure we start with fully young GCs after the
1003 // Full GC.
1004 set_full_young_gcs(true);
1005 _last_full_young_gc = false;
1006 _should_revert_to_full_young_gcs = false;
1007 _should_initiate_conc_mark = false;
1008 _known_garbage_bytes = 0;
1009 _known_garbage_ratio = 0.0;
1010 _in_marking_window = false;
1011 _in_marking_window_im = false;
1013 _short_lived_surv_rate_group->record_scan_only_prefix(0);
1014 _short_lived_surv_rate_group->start_adding_regions();
1015 // also call this on any additional surv rate groups
1017 record_survivor_regions(0, NULL, NULL);
1019 _prev_region_num_young = _region_num_young;
1020 _prev_region_num_tenured = _region_num_tenured;
1022 _free_regions_at_end_of_collection = _g1->free_regions();
1023 _scan_only_regions_at_end_of_collection = 0;
1024 // Reset survivors SurvRateGroup.
1025 _survivor_surv_rate_group->reset();
1026 calculate_young_list_min_length();
1027 calculate_young_list_target_config();
1028 }
1030 void G1CollectorPolicy::record_before_bytes(size_t bytes) {
1031 _bytes_in_to_space_before_gc += bytes;
1032 }
1034 void G1CollectorPolicy::record_after_bytes(size_t bytes) {
1035 _bytes_in_to_space_after_gc += bytes;
1036 }
1038 void G1CollectorPolicy::record_stop_world_start() {
1039 _stop_world_start = os::elapsedTime();
1040 }
1042 void G1CollectorPolicy::record_collection_pause_start(double start_time_sec,
1043 size_t start_used) {
1044 if (PrintGCDetails) {
1045 gclog_or_tty->stamp(PrintGCTimeStamps);
1046 gclog_or_tty->print("[GC pause");
1047 if (in_young_gc_mode())
1048 gclog_or_tty->print(" (%s)", full_young_gcs() ? "young" : "partial");
1049 }
1051 assert(_g1->used_regions() == _g1->recalculate_used_regions(),
1052 "sanity");
1053 assert(_g1->used() == _g1->recalculate_used(), "sanity");
1055 double s_w_t_ms = (start_time_sec - _stop_world_start) * 1000.0;
1056 _all_stop_world_times_ms->add(s_w_t_ms);
1057 _stop_world_start = 0.0;
1059 _cur_collection_start_sec = start_time_sec;
1060 _cur_collection_pause_used_at_start_bytes = start_used;
1061 _cur_collection_pause_used_regions_at_start = _g1->used_regions();
1062 _pending_cards = _g1->pending_card_num();
1063 _max_pending_cards = _g1->max_pending_card_num();
1065 _bytes_in_to_space_before_gc = 0;
1066 _bytes_in_to_space_after_gc = 0;
1067 _bytes_in_collection_set_before_gc = 0;
1069 #ifdef DEBUG
1070 // initialise these to something well known so that we can spot
1071 // if they are not set properly
1073 for (int i = 0; i < _parallel_gc_threads; ++i) {
1074 _par_last_ext_root_scan_times_ms[i] = -666.0;
1075 _par_last_mark_stack_scan_times_ms[i] = -666.0;
1076 _par_last_scan_only_times_ms[i] = -666.0;
1077 _par_last_scan_only_regions_scanned[i] = -666.0;
1078 _par_last_update_rs_start_times_ms[i] = -666.0;
1079 _par_last_update_rs_times_ms[i] = -666.0;
1080 _par_last_update_rs_processed_buffers[i] = -666.0;
1081 _par_last_scan_rs_start_times_ms[i] = -666.0;
1082 _par_last_scan_rs_times_ms[i] = -666.0;
1083 _par_last_scan_new_refs_times_ms[i] = -666.0;
1084 _par_last_obj_copy_times_ms[i] = -666.0;
1085 _par_last_termination_times_ms[i] = -666.0;
1086 }
1087 #endif
1089 for (int i = 0; i < _aux_num; ++i) {
1090 _cur_aux_times_ms[i] = 0.0;
1091 _cur_aux_times_set[i] = false;
1092 }
1094 _satb_drain_time_set = false;
1095 _last_satb_drain_processed_buffers = -1;
1097 if (in_young_gc_mode())
1098 _last_young_gc_full = false;
1101 // do that for any other surv rate groups
1102 _short_lived_surv_rate_group->stop_adding_regions();
1103 size_t short_lived_so_length = _young_list_so_prefix_length;
1104 _short_lived_surv_rate_group->record_scan_only_prefix(short_lived_so_length);
1105 tag_scan_only(short_lived_so_length);
1107 if (G1UseSurvivorSpaces) {
1108 _survivors_age_table.clear();
1109 }
1111 assert( verify_young_ages(), "region age verification" );
1112 }
1114 void G1CollectorPolicy::tag_scan_only(size_t short_lived_scan_only_length) {
1115 // done in a way that it can be extended for other surv rate groups too...
1117 HeapRegion* head = _g1->young_list_first_region();
1118 bool finished_short_lived = (short_lived_scan_only_length == 0);
1120 if (finished_short_lived)
1121 return;
1123 for (HeapRegion* curr = head;
1124 curr != NULL;
1125 curr = curr->get_next_young_region()) {
1126 SurvRateGroup* surv_rate_group = curr->surv_rate_group();
1127 int age = curr->age_in_surv_rate_group();
1129 if (surv_rate_group == _short_lived_surv_rate_group) {
1130 if ((size_t)age < short_lived_scan_only_length)
1131 curr->set_scan_only();
1132 else
1133 finished_short_lived = true;
1134 }
1137 if (finished_short_lived)
1138 return;
1139 }
1141 guarantee( false, "we should never reach here" );
1142 }
1144 void G1CollectorPolicy::record_mark_closure_time(double mark_closure_time_ms) {
1145 _mark_closure_time_ms = mark_closure_time_ms;
1146 }
1148 void G1CollectorPolicy::record_concurrent_mark_init_start() {
1149 _mark_init_start_sec = os::elapsedTime();
1150 guarantee(!in_young_gc_mode(), "should not do be here in young GC mode");
1151 }
1153 void G1CollectorPolicy::record_concurrent_mark_init_end_pre(double
1154 mark_init_elapsed_time_ms) {
1155 _during_marking = true;
1156 _should_initiate_conc_mark = false;
1157 _cur_mark_stop_world_time_ms = mark_init_elapsed_time_ms;
1158 }
1160 void G1CollectorPolicy::record_concurrent_mark_init_end() {
1161 double end_time_sec = os::elapsedTime();
1162 double elapsed_time_ms = (end_time_sec - _mark_init_start_sec) * 1000.0;
1163 _concurrent_mark_init_times_ms->add(elapsed_time_ms);
1164 checkpoint_conc_overhead();
1165 record_concurrent_mark_init_end_pre(elapsed_time_ms);
1167 _mmu_tracker->add_pause(_mark_init_start_sec, end_time_sec, true);
1168 }
1170 void G1CollectorPolicy::record_concurrent_mark_remark_start() {
1171 _mark_remark_start_sec = os::elapsedTime();
1172 _during_marking = false;
1173 }
1175 void G1CollectorPolicy::record_concurrent_mark_remark_end() {
1176 double end_time_sec = os::elapsedTime();
1177 double elapsed_time_ms = (end_time_sec - _mark_remark_start_sec)*1000.0;
1178 checkpoint_conc_overhead();
1179 _concurrent_mark_remark_times_ms->add(elapsed_time_ms);
1180 _cur_mark_stop_world_time_ms += elapsed_time_ms;
1181 _prev_collection_pause_end_ms += elapsed_time_ms;
1183 _mmu_tracker->add_pause(_mark_remark_start_sec, end_time_sec, true);
1184 }
1186 void G1CollectorPolicy::record_concurrent_mark_cleanup_start() {
1187 _mark_cleanup_start_sec = os::elapsedTime();
1188 }
1190 void
1191 G1CollectorPolicy::record_concurrent_mark_cleanup_end(size_t freed_bytes,
1192 size_t max_live_bytes) {
1193 record_concurrent_mark_cleanup_end_work1(freed_bytes, max_live_bytes);
1194 record_concurrent_mark_cleanup_end_work2();
1195 }
1197 void
1198 G1CollectorPolicy::
1199 record_concurrent_mark_cleanup_end_work1(size_t freed_bytes,
1200 size_t max_live_bytes) {
1201 if (_n_marks < 2) _n_marks++;
1202 if (G1PolicyVerbose > 0)
1203 gclog_or_tty->print_cr("At end of marking, max_live is " SIZE_FORMAT " MB "
1204 " (of " SIZE_FORMAT " MB heap).",
1205 max_live_bytes/M, _g1->capacity()/M);
1206 }
1208 // The important thing about this is that it includes "os::elapsedTime".
1209 void G1CollectorPolicy::record_concurrent_mark_cleanup_end_work2() {
1210 checkpoint_conc_overhead();
1211 double end_time_sec = os::elapsedTime();
1212 double elapsed_time_ms = (end_time_sec - _mark_cleanup_start_sec)*1000.0;
1213 _concurrent_mark_cleanup_times_ms->add(elapsed_time_ms);
1214 _cur_mark_stop_world_time_ms += elapsed_time_ms;
1215 _prev_collection_pause_end_ms += elapsed_time_ms;
1217 _mmu_tracker->add_pause(_mark_cleanup_start_sec, end_time_sec, true);
1219 _num_markings++;
1221 // We did a marking, so reset the "since_last_mark" variables.
1222 double considerConcMarkCost = 1.0;
1223 // If there are available processors, concurrent activity is free...
1224 if (Threads::number_of_non_daemon_threads() * 2 <
1225 os::active_processor_count()) {
1226 considerConcMarkCost = 0.0;
1227 }
1228 _n_pauses_at_mark_end = _n_pauses;
1229 _n_marks_since_last_pause++;
1230 _conc_mark_initiated = false;
1231 }
1233 void
1234 G1CollectorPolicy::record_concurrent_mark_cleanup_completed() {
1235 if (in_young_gc_mode()) {
1236 _should_revert_to_full_young_gcs = false;
1237 _last_full_young_gc = true;
1238 _in_marking_window = false;
1239 if (adaptive_young_list_length())
1240 calculate_young_list_target_config();
1241 }
1242 }
1244 void G1CollectorPolicy::record_concurrent_pause() {
1245 if (_stop_world_start > 0.0) {
1246 double yield_ms = (os::elapsedTime() - _stop_world_start) * 1000.0;
1247 _all_yield_times_ms->add(yield_ms);
1248 }
1249 }
1251 void G1CollectorPolicy::record_concurrent_pause_end() {
1252 }
1254 void G1CollectorPolicy::record_collection_pause_end_CH_strong_roots() {
1255 _cur_CH_strong_roots_end_sec = os::elapsedTime();
1256 _cur_CH_strong_roots_dur_ms =
1257 (_cur_CH_strong_roots_end_sec - _cur_collection_start_sec) * 1000.0;
1258 }
1260 void G1CollectorPolicy::record_collection_pause_end_G1_strong_roots() {
1261 _cur_G1_strong_roots_end_sec = os::elapsedTime();
1262 _cur_G1_strong_roots_dur_ms =
1263 (_cur_G1_strong_roots_end_sec - _cur_CH_strong_roots_end_sec) * 1000.0;
1264 }
1266 template<class T>
1267 T sum_of(T* sum_arr, int start, int n, int N) {
1268 T sum = (T)0;
1269 for (int i = 0; i < n; i++) {
1270 int j = (start + i) % N;
1271 sum += sum_arr[j];
1272 }
1273 return sum;
1274 }
1276 void G1CollectorPolicy::print_par_stats (int level,
1277 const char* str,
1278 double* data,
1279 bool summary) {
1280 double min = data[0], max = data[0];
1281 double total = 0.0;
1282 int j;
1283 for (j = 0; j < level; ++j)
1284 gclog_or_tty->print(" ");
1285 gclog_or_tty->print("[%s (ms):", str);
1286 for (uint i = 0; i < ParallelGCThreads; ++i) {
1287 double val = data[i];
1288 if (val < min)
1289 min = val;
1290 if (val > max)
1291 max = val;
1292 total += val;
1293 gclog_or_tty->print(" %3.1lf", val);
1294 }
1295 if (summary) {
1296 gclog_or_tty->print_cr("");
1297 double avg = total / (double) ParallelGCThreads;
1298 gclog_or_tty->print(" ");
1299 for (j = 0; j < level; ++j)
1300 gclog_or_tty->print(" ");
1301 gclog_or_tty->print("Avg: %5.1lf, Min: %5.1lf, Max: %5.1lf",
1302 avg, min, max);
1303 }
1304 gclog_or_tty->print_cr("]");
1305 }
1307 void G1CollectorPolicy::print_par_buffers (int level,
1308 const char* str,
1309 double* data,
1310 bool summary) {
1311 double min = data[0], max = data[0];
1312 double total = 0.0;
1313 int j;
1314 for (j = 0; j < level; ++j)
1315 gclog_or_tty->print(" ");
1316 gclog_or_tty->print("[%s :", str);
1317 for (uint i = 0; i < ParallelGCThreads; ++i) {
1318 double val = data[i];
1319 if (val < min)
1320 min = val;
1321 if (val > max)
1322 max = val;
1323 total += val;
1324 gclog_or_tty->print(" %d", (int) val);
1325 }
1326 if (summary) {
1327 gclog_or_tty->print_cr("");
1328 double avg = total / (double) ParallelGCThreads;
1329 gclog_or_tty->print(" ");
1330 for (j = 0; j < level; ++j)
1331 gclog_or_tty->print(" ");
1332 gclog_or_tty->print("Sum: %d, Avg: %d, Min: %d, Max: %d",
1333 (int)total, (int)avg, (int)min, (int)max);
1334 }
1335 gclog_or_tty->print_cr("]");
1336 }
1338 void G1CollectorPolicy::print_stats (int level,
1339 const char* str,
1340 double value) {
1341 for (int j = 0; j < level; ++j)
1342 gclog_or_tty->print(" ");
1343 gclog_or_tty->print_cr("[%s: %5.1lf ms]", str, value);
1344 }
1346 void G1CollectorPolicy::print_stats (int level,
1347 const char* str,
1348 int value) {
1349 for (int j = 0; j < level; ++j)
1350 gclog_or_tty->print(" ");
1351 gclog_or_tty->print_cr("[%s: %d]", str, value);
1352 }
1354 double G1CollectorPolicy::avg_value (double* data) {
1355 if (ParallelGCThreads > 0) {
1356 double ret = 0.0;
1357 for (uint i = 0; i < ParallelGCThreads; ++i)
1358 ret += data[i];
1359 return ret / (double) ParallelGCThreads;
1360 } else {
1361 return data[0];
1362 }
1363 }
1365 double G1CollectorPolicy::max_value (double* data) {
1366 if (ParallelGCThreads > 0) {
1367 double ret = data[0];
1368 for (uint i = 1; i < ParallelGCThreads; ++i)
1369 if (data[i] > ret)
1370 ret = data[i];
1371 return ret;
1372 } else {
1373 return data[0];
1374 }
1375 }
1377 double G1CollectorPolicy::sum_of_values (double* data) {
1378 if (ParallelGCThreads > 0) {
1379 double sum = 0.0;
1380 for (uint i = 0; i < ParallelGCThreads; i++)
1381 sum += data[i];
1382 return sum;
1383 } else {
1384 return data[0];
1385 }
1386 }
1388 double G1CollectorPolicy::max_sum (double* data1,
1389 double* data2) {
1390 double ret = data1[0] + data2[0];
1392 if (ParallelGCThreads > 0) {
1393 for (uint i = 1; i < ParallelGCThreads; ++i) {
1394 double data = data1[i] + data2[i];
1395 if (data > ret)
1396 ret = data;
1397 }
1398 }
1399 return ret;
1400 }
1402 // Anything below that is considered to be zero
1403 #define MIN_TIMER_GRANULARITY 0.0000001
1405 void G1CollectorPolicy::record_collection_pause_end(bool abandoned) {
1406 double end_time_sec = os::elapsedTime();
1407 double elapsed_ms = _last_pause_time_ms;
1408 bool parallel = ParallelGCThreads > 0;
1409 double evac_ms = (end_time_sec - _cur_G1_strong_roots_end_sec) * 1000.0;
1410 size_t rs_size =
1411 _cur_collection_pause_used_regions_at_start - collection_set_size();
1412 size_t cur_used_bytes = _g1->used();
1413 assert(cur_used_bytes == _g1->recalculate_used(), "It should!");
1414 bool last_pause_included_initial_mark = false;
1415 bool update_stats = !abandoned && !_g1->evacuation_failed();
1417 #ifndef PRODUCT
1418 if (G1YoungSurvRateVerbose) {
1419 gclog_or_tty->print_cr("");
1420 _short_lived_surv_rate_group->print();
1421 // do that for any other surv rate groups too
1422 }
1423 #endif // PRODUCT
1425 checkpoint_conc_overhead();
1427 if (in_young_gc_mode()) {
1428 last_pause_included_initial_mark = _should_initiate_conc_mark;
1429 if (last_pause_included_initial_mark)
1430 record_concurrent_mark_init_end_pre(0.0);
1432 size_t min_used_targ =
1433 (_g1->capacity() / 100) * (G1SteadyStateUsed - G1SteadyStateUsedDelta);
1435 if (cur_used_bytes > min_used_targ) {
1436 if (cur_used_bytes <= _prev_collection_pause_used_at_end_bytes) {
1437 } else if (!_g1->mark_in_progress() && !_last_full_young_gc) {
1438 _should_initiate_conc_mark = true;
1439 }
1440 }
1442 _prev_collection_pause_used_at_end_bytes = cur_used_bytes;
1443 }
1445 _mmu_tracker->add_pause(end_time_sec - elapsed_ms/1000.0,
1446 end_time_sec, false);
1448 guarantee(_cur_collection_pause_used_regions_at_start >=
1449 collection_set_size(),
1450 "Negative RS size?");
1452 // This assert is exempted when we're doing parallel collection pauses,
1453 // because the fragmentation caused by the parallel GC allocation buffers
1454 // can lead to more memory being used during collection than was used
1455 // before. Best leave this out until the fragmentation problem is fixed.
1456 // Pauses in which evacuation failed can also lead to negative
1457 // collections, since no space is reclaimed from a region containing an
1458 // object whose evacuation failed.
1459 // Further, we're now always doing parallel collection. But I'm still
1460 // leaving this here as a placeholder for a more precise assertion later.
1461 // (DLD, 10/05.)
1462 assert((true || parallel) // Always using GC LABs now.
1463 || _g1->evacuation_failed()
1464 || _cur_collection_pause_used_at_start_bytes >= cur_used_bytes,
1465 "Negative collection");
1467 size_t freed_bytes =
1468 _cur_collection_pause_used_at_start_bytes - cur_used_bytes;
1469 size_t surviving_bytes = _collection_set_bytes_used_before - freed_bytes;
1470 double survival_fraction =
1471 (double)surviving_bytes/
1472 (double)_collection_set_bytes_used_before;
1474 _n_pauses++;
1476 if (update_stats) {
1477 _recent_CH_strong_roots_times_ms->add(_cur_CH_strong_roots_dur_ms);
1478 _recent_G1_strong_roots_times_ms->add(_cur_G1_strong_roots_dur_ms);
1479 _recent_evac_times_ms->add(evac_ms);
1480 _recent_pause_times_ms->add(elapsed_ms);
1482 _recent_rs_sizes->add(rs_size);
1484 // We exempt parallel collection from this check because Alloc Buffer
1485 // fragmentation can produce negative collections. Same with evac
1486 // failure.
1487 // Further, we're now always doing parallel collection. But I'm still
1488 // leaving this here as a placeholder for a more precise assertion later.
1489 // (DLD, 10/05.
1490 assert((true || parallel)
1491 || _g1->evacuation_failed()
1492 || surviving_bytes <= _collection_set_bytes_used_before,
1493 "Or else negative collection!");
1494 _recent_CS_bytes_used_before->add(_collection_set_bytes_used_before);
1495 _recent_CS_bytes_surviving->add(surviving_bytes);
1497 // this is where we update the allocation rate of the application
1498 double app_time_ms =
1499 (_cur_collection_start_sec * 1000.0 - _prev_collection_pause_end_ms);
1500 if (app_time_ms < MIN_TIMER_GRANULARITY) {
1501 // This usually happens due to the timer not having the required
1502 // granularity. Some Linuxes are the usual culprits.
1503 // We'll just set it to something (arbitrarily) small.
1504 app_time_ms = 1.0;
1505 }
1506 size_t regions_allocated =
1507 (_region_num_young - _prev_region_num_young) +
1508 (_region_num_tenured - _prev_region_num_tenured);
1509 double alloc_rate_ms = (double) regions_allocated / app_time_ms;
1510 _alloc_rate_ms_seq->add(alloc_rate_ms);
1511 _prev_region_num_young = _region_num_young;
1512 _prev_region_num_tenured = _region_num_tenured;
1514 double interval_ms =
1515 (end_time_sec - _recent_prev_end_times_for_all_gcs_sec->oldest()) * 1000.0;
1516 update_recent_gc_times(end_time_sec, elapsed_ms);
1517 _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum()/interval_ms;
1518 assert(recent_avg_pause_time_ratio() < 1.00, "All GC?");
1519 }
1521 if (G1PolicyVerbose > 1) {
1522 gclog_or_tty->print_cr(" Recording collection pause(%d)", _n_pauses);
1523 }
1525 PauseSummary* summary;
1526 if (abandoned) {
1527 summary = _abandoned_summary;
1528 } else {
1529 summary = _summary;
1530 }
1532 double ext_root_scan_time = avg_value(_par_last_ext_root_scan_times_ms);
1533 double mark_stack_scan_time = avg_value(_par_last_mark_stack_scan_times_ms);
1534 double scan_only_time = avg_value(_par_last_scan_only_times_ms);
1535 double scan_only_regions_scanned =
1536 sum_of_values(_par_last_scan_only_regions_scanned);
1537 double update_rs_time = avg_value(_par_last_update_rs_times_ms);
1538 double update_rs_processed_buffers =
1539 sum_of_values(_par_last_update_rs_processed_buffers);
1540 double scan_rs_time = avg_value(_par_last_scan_rs_times_ms);
1541 double obj_copy_time = avg_value(_par_last_obj_copy_times_ms);
1542 double termination_time = avg_value(_par_last_termination_times_ms);
1544 double parallel_other_time = _cur_collection_par_time_ms -
1545 (update_rs_time + ext_root_scan_time + mark_stack_scan_time +
1546 scan_only_time + scan_rs_time + obj_copy_time + termination_time);
1547 if (update_stats) {
1548 MainBodySummary* body_summary = summary->main_body_summary();
1549 guarantee(body_summary != NULL, "should not be null!");
1551 if (_satb_drain_time_set)
1552 body_summary->record_satb_drain_time_ms(_cur_satb_drain_time_ms);
1553 else
1554 body_summary->record_satb_drain_time_ms(0.0);
1555 body_summary->record_ext_root_scan_time_ms(ext_root_scan_time);
1556 body_summary->record_mark_stack_scan_time_ms(mark_stack_scan_time);
1557 body_summary->record_scan_only_time_ms(scan_only_time);
1558 body_summary->record_update_rs_time_ms(update_rs_time);
1559 body_summary->record_scan_rs_time_ms(scan_rs_time);
1560 body_summary->record_obj_copy_time_ms(obj_copy_time);
1561 if (parallel) {
1562 body_summary->record_parallel_time_ms(_cur_collection_par_time_ms);
1563 body_summary->record_clear_ct_time_ms(_cur_clear_ct_time_ms);
1564 body_summary->record_termination_time_ms(termination_time);
1565 body_summary->record_parallel_other_time_ms(parallel_other_time);
1566 }
1567 body_summary->record_mark_closure_time_ms(_mark_closure_time_ms);
1568 }
1570 if (G1PolicyVerbose > 1) {
1571 gclog_or_tty->print_cr(" ET: %10.6f ms (avg: %10.6f ms)\n"
1572 " CH Strong: %10.6f ms (avg: %10.6f ms)\n"
1573 " G1 Strong: %10.6f ms (avg: %10.6f ms)\n"
1574 " Evac: %10.6f ms (avg: %10.6f ms)\n"
1575 " ET-RS: %10.6f ms (avg: %10.6f ms)\n"
1576 " |RS|: " SIZE_FORMAT,
1577 elapsed_ms, recent_avg_time_for_pauses_ms(),
1578 _cur_CH_strong_roots_dur_ms, recent_avg_time_for_CH_strong_ms(),
1579 _cur_G1_strong_roots_dur_ms, recent_avg_time_for_G1_strong_ms(),
1580 evac_ms, recent_avg_time_for_evac_ms(),
1581 scan_rs_time,
1582 recent_avg_time_for_pauses_ms() -
1583 recent_avg_time_for_G1_strong_ms(),
1584 rs_size);
1586 gclog_or_tty->print_cr(" Used at start: " SIZE_FORMAT"K"
1587 " At end " SIZE_FORMAT "K\n"
1588 " garbage : " SIZE_FORMAT "K"
1589 " of " SIZE_FORMAT "K\n"
1590 " survival : %6.2f%% (%6.2f%% avg)",
1591 _cur_collection_pause_used_at_start_bytes/K,
1592 _g1->used()/K, freed_bytes/K,
1593 _collection_set_bytes_used_before/K,
1594 survival_fraction*100.0,
1595 recent_avg_survival_fraction()*100.0);
1596 gclog_or_tty->print_cr(" Recent %% gc pause time: %6.2f",
1597 recent_avg_pause_time_ratio() * 100.0);
1598 }
1600 double other_time_ms = elapsed_ms;
1602 if (!abandoned) {
1603 if (_satb_drain_time_set)
1604 other_time_ms -= _cur_satb_drain_time_ms;
1606 if (parallel)
1607 other_time_ms -= _cur_collection_par_time_ms + _cur_clear_ct_time_ms;
1608 else
1609 other_time_ms -=
1610 update_rs_time +
1611 ext_root_scan_time + mark_stack_scan_time + scan_only_time +
1612 scan_rs_time + obj_copy_time;
1613 }
1615 if (PrintGCDetails) {
1616 gclog_or_tty->print_cr("%s%s, %1.8lf secs]",
1617 abandoned ? " (abandoned)" : "",
1618 (last_pause_included_initial_mark) ? " (initial-mark)" : "",
1619 elapsed_ms / 1000.0);
1621 if (!abandoned) {
1622 if (_satb_drain_time_set) {
1623 print_stats(1, "SATB Drain Time", _cur_satb_drain_time_ms);
1624 }
1625 if (_last_satb_drain_processed_buffers >= 0) {
1626 print_stats(2, "Processed Buffers", _last_satb_drain_processed_buffers);
1627 }
1628 if (parallel) {
1629 print_stats(1, "Parallel Time", _cur_collection_par_time_ms);
1630 print_par_stats(2, "Update RS (Start)", _par_last_update_rs_start_times_ms, false);
1631 print_par_stats(2, "Update RS", _par_last_update_rs_times_ms);
1632 print_par_buffers(3, "Processed Buffers",
1633 _par_last_update_rs_processed_buffers, true);
1634 print_par_stats(2, "Ext Root Scanning", _par_last_ext_root_scan_times_ms);
1635 print_par_stats(2, "Mark Stack Scanning", _par_last_mark_stack_scan_times_ms);
1636 print_par_stats(2, "Scan-Only Scanning", _par_last_scan_only_times_ms);
1637 print_par_buffers(3, "Scan-Only Regions",
1638 _par_last_scan_only_regions_scanned, true);
1639 print_par_stats(2, "Scan RS", _par_last_scan_rs_times_ms);
1640 print_par_stats(2, "Object Copy", _par_last_obj_copy_times_ms);
1641 print_par_stats(2, "Termination", _par_last_termination_times_ms);
1642 print_stats(2, "Other", parallel_other_time);
1643 print_stats(1, "Clear CT", _cur_clear_ct_time_ms);
1644 } else {
1645 print_stats(1, "Update RS", update_rs_time);
1646 print_stats(2, "Processed Buffers",
1647 (int)update_rs_processed_buffers);
1648 print_stats(1, "Ext Root Scanning", ext_root_scan_time);
1649 print_stats(1, "Mark Stack Scanning", mark_stack_scan_time);
1650 print_stats(1, "Scan-Only Scanning", scan_only_time);
1651 print_stats(1, "Scan RS", scan_rs_time);
1652 print_stats(1, "Object Copying", obj_copy_time);
1653 }
1654 }
1655 print_stats(1, "Other", other_time_ms);
1656 for (int i = 0; i < _aux_num; ++i) {
1657 if (_cur_aux_times_set[i]) {
1658 char buffer[96];
1659 sprintf(buffer, "Aux%d", i);
1660 print_stats(1, buffer, _cur_aux_times_ms[i]);
1661 }
1662 }
1663 }
1664 if (PrintGCDetails)
1665 gclog_or_tty->print(" [");
1666 if (PrintGC || PrintGCDetails)
1667 _g1->print_size_transition(gclog_or_tty,
1668 _cur_collection_pause_used_at_start_bytes,
1669 _g1->used(), _g1->capacity());
1670 if (PrintGCDetails)
1671 gclog_or_tty->print_cr("]");
1673 _all_pause_times_ms->add(elapsed_ms);
1674 if (update_stats) {
1675 summary->record_total_time_ms(elapsed_ms);
1676 summary->record_other_time_ms(other_time_ms);
1677 }
1678 for (int i = 0; i < _aux_num; ++i)
1679 if (_cur_aux_times_set[i])
1680 _all_aux_times_ms[i].add(_cur_aux_times_ms[i]);
1682 // Reset marks-between-pauses counter.
1683 _n_marks_since_last_pause = 0;
1685 // Update the efficiency-since-mark vars.
1686 double proc_ms = elapsed_ms * (double) _parallel_gc_threads;
1687 if (elapsed_ms < MIN_TIMER_GRANULARITY) {
1688 // This usually happens due to the timer not having the required
1689 // granularity. Some Linuxes are the usual culprits.
1690 // We'll just set it to something (arbitrarily) small.
1691 proc_ms = 1.0;
1692 }
1693 double cur_efficiency = (double) freed_bytes / proc_ms;
1695 bool new_in_marking_window = _in_marking_window;
1696 bool new_in_marking_window_im = false;
1697 if (_should_initiate_conc_mark) {
1698 new_in_marking_window = true;
1699 new_in_marking_window_im = true;
1700 }
1702 if (in_young_gc_mode()) {
1703 if (_last_full_young_gc) {
1704 set_full_young_gcs(false);
1705 _last_full_young_gc = false;
1706 }
1708 if ( !_last_young_gc_full ) {
1709 if ( _should_revert_to_full_young_gcs ||
1710 _known_garbage_ratio < 0.05 ||
1711 (adaptive_young_list_length() &&
1712 (get_gc_eff_factor() * cur_efficiency < predict_young_gc_eff())) ) {
1713 set_full_young_gcs(true);
1714 }
1715 }
1716 _should_revert_to_full_young_gcs = false;
1718 if (_last_young_gc_full && !_during_marking)
1719 _young_gc_eff_seq->add(cur_efficiency);
1720 }
1722 _short_lived_surv_rate_group->start_adding_regions();
1723 // do that for any other surv rate groupsx
1725 // <NEW PREDICTION>
1727 if (update_stats) {
1728 double pause_time_ms = elapsed_ms;
1730 size_t diff = 0;
1731 if (_max_pending_cards >= _pending_cards)
1732 diff = _max_pending_cards - _pending_cards;
1733 _pending_card_diff_seq->add((double) diff);
1735 double cost_per_card_ms = 0.0;
1736 if (_pending_cards > 0) {
1737 cost_per_card_ms = update_rs_time / (double) _pending_cards;
1738 _cost_per_card_ms_seq->add(cost_per_card_ms);
1739 }
1741 double cost_per_scan_only_region_ms = 0.0;
1742 if (scan_only_regions_scanned > 0.0) {
1743 cost_per_scan_only_region_ms =
1744 scan_only_time / scan_only_regions_scanned;
1745 if (_in_marking_window_im)
1746 _cost_per_scan_only_region_ms_during_cm_seq->add(cost_per_scan_only_region_ms);
1747 else
1748 _cost_per_scan_only_region_ms_seq->add(cost_per_scan_only_region_ms);
1749 }
1751 size_t cards_scanned = _g1->cards_scanned();
1753 double cost_per_entry_ms = 0.0;
1754 if (cards_scanned > 10) {
1755 cost_per_entry_ms = scan_rs_time / (double) cards_scanned;
1756 if (_last_young_gc_full)
1757 _cost_per_entry_ms_seq->add(cost_per_entry_ms);
1758 else
1759 _partially_young_cost_per_entry_ms_seq->add(cost_per_entry_ms);
1760 }
1762 if (_max_rs_lengths > 0) {
1763 double cards_per_entry_ratio =
1764 (double) cards_scanned / (double) _max_rs_lengths;
1765 if (_last_young_gc_full)
1766 _fully_young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
1767 else
1768 _partially_young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
1769 }
1771 size_t rs_length_diff = _max_rs_lengths - _recorded_rs_lengths;
1772 if (rs_length_diff >= 0)
1773 _rs_length_diff_seq->add((double) rs_length_diff);
1775 size_t copied_bytes = surviving_bytes;
1776 double cost_per_byte_ms = 0.0;
1777 if (copied_bytes > 0) {
1778 cost_per_byte_ms = obj_copy_time / (double) copied_bytes;
1779 if (_in_marking_window)
1780 _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms);
1781 else
1782 _cost_per_byte_ms_seq->add(cost_per_byte_ms);
1783 }
1785 double all_other_time_ms = pause_time_ms -
1786 (update_rs_time + scan_only_time + scan_rs_time + obj_copy_time +
1787 _mark_closure_time_ms + termination_time);
1789 double young_other_time_ms = 0.0;
1790 if (_recorded_young_regions > 0) {
1791 young_other_time_ms =
1792 _recorded_young_cset_choice_time_ms +
1793 _recorded_young_free_cset_time_ms;
1794 _young_other_cost_per_region_ms_seq->add(young_other_time_ms /
1795 (double) _recorded_young_regions);
1796 }
1797 double non_young_other_time_ms = 0.0;
1798 if (_recorded_non_young_regions > 0) {
1799 non_young_other_time_ms =
1800 _recorded_non_young_cset_choice_time_ms +
1801 _recorded_non_young_free_cset_time_ms;
1803 _non_young_other_cost_per_region_ms_seq->add(non_young_other_time_ms /
1804 (double) _recorded_non_young_regions);
1805 }
1807 double constant_other_time_ms = all_other_time_ms -
1808 (young_other_time_ms + non_young_other_time_ms);
1809 _constant_other_time_ms_seq->add(constant_other_time_ms);
1811 double survival_ratio = 0.0;
1812 if (_bytes_in_collection_set_before_gc > 0) {
1813 survival_ratio = (double) bytes_in_to_space_during_gc() /
1814 (double) _bytes_in_collection_set_before_gc;
1815 }
1817 _pending_cards_seq->add((double) _pending_cards);
1818 _scanned_cards_seq->add((double) cards_scanned);
1819 _rs_lengths_seq->add((double) _max_rs_lengths);
1821 double expensive_region_limit_ms =
1822 (double) MaxGCPauseMillis - predict_constant_other_time_ms();
1823 if (expensive_region_limit_ms < 0.0) {
1824 // this means that the other time was predicted to be longer than
1825 // than the max pause time
1826 expensive_region_limit_ms = (double) MaxGCPauseMillis;
1827 }
1828 _expensive_region_limit_ms = expensive_region_limit_ms;
1830 if (PREDICTIONS_VERBOSE) {
1831 gclog_or_tty->print_cr("");
1832 gclog_or_tty->print_cr("PREDICTIONS %1.4lf %d "
1833 "REGIONS %d %d %d %d "
1834 "PENDING_CARDS %d %d "
1835 "CARDS_SCANNED %d %d "
1836 "RS_LENGTHS %d %d "
1837 "SCAN_ONLY_SCAN %1.6lf %1.6lf "
1838 "RS_UPDATE %1.6lf %1.6lf RS_SCAN %1.6lf %1.6lf "
1839 "SURVIVAL_RATIO %1.6lf %1.6lf "
1840 "OBJECT_COPY %1.6lf %1.6lf OTHER_CONSTANT %1.6lf %1.6lf "
1841 "OTHER_YOUNG %1.6lf %1.6lf "
1842 "OTHER_NON_YOUNG %1.6lf %1.6lf "
1843 "VTIME_DIFF %1.6lf TERMINATION %1.6lf "
1844 "ELAPSED %1.6lf %1.6lf ",
1845 _cur_collection_start_sec,
1846 (!_last_young_gc_full) ? 2 :
1847 (last_pause_included_initial_mark) ? 1 : 0,
1848 _recorded_region_num,
1849 _recorded_young_regions,
1850 _recorded_scan_only_regions,
1851 _recorded_non_young_regions,
1852 _predicted_pending_cards, _pending_cards,
1853 _predicted_cards_scanned, cards_scanned,
1854 _predicted_rs_lengths, _max_rs_lengths,
1855 _predicted_scan_only_scan_time_ms, scan_only_time,
1856 _predicted_rs_update_time_ms, update_rs_time,
1857 _predicted_rs_scan_time_ms, scan_rs_time,
1858 _predicted_survival_ratio, survival_ratio,
1859 _predicted_object_copy_time_ms, obj_copy_time,
1860 _predicted_constant_other_time_ms, constant_other_time_ms,
1861 _predicted_young_other_time_ms, young_other_time_ms,
1862 _predicted_non_young_other_time_ms,
1863 non_young_other_time_ms,
1864 _vtime_diff_ms, termination_time,
1865 _predicted_pause_time_ms, elapsed_ms);
1866 }
1868 if (G1PolicyVerbose > 0) {
1869 gclog_or_tty->print_cr("Pause Time, predicted: %1.4lfms (predicted %s), actual: %1.4lfms",
1870 _predicted_pause_time_ms,
1871 (_within_target) ? "within" : "outside",
1872 elapsed_ms);
1873 }
1875 }
1877 _in_marking_window = new_in_marking_window;
1878 _in_marking_window_im = new_in_marking_window_im;
1879 _free_regions_at_end_of_collection = _g1->free_regions();
1880 _scan_only_regions_at_end_of_collection = _g1->young_list_length();
1881 calculate_young_list_min_length();
1882 calculate_young_list_target_config();
1884 // </NEW PREDICTION>
1886 _target_pause_time_ms = -1.0;
1887 }
1889 // <NEW PREDICTION>
1891 double
1892 G1CollectorPolicy::
1893 predict_young_collection_elapsed_time_ms(size_t adjustment) {
1894 guarantee( adjustment == 0 || adjustment == 1, "invariant" );
1896 G1CollectedHeap* g1h = G1CollectedHeap::heap();
1897 size_t young_num = g1h->young_list_length();
1898 if (young_num == 0)
1899 return 0.0;
1901 young_num += adjustment;
1902 size_t pending_cards = predict_pending_cards();
1903 size_t rs_lengths = g1h->young_list_sampled_rs_lengths() +
1904 predict_rs_length_diff();
1905 size_t card_num;
1906 if (full_young_gcs())
1907 card_num = predict_young_card_num(rs_lengths);
1908 else
1909 card_num = predict_non_young_card_num(rs_lengths);
1910 size_t young_byte_size = young_num * HeapRegion::GrainBytes;
1911 double accum_yg_surv_rate =
1912 _short_lived_surv_rate_group->accum_surv_rate(adjustment);
1914 size_t bytes_to_copy =
1915 (size_t) (accum_yg_surv_rate * (double) HeapRegion::GrainBytes);
1917 return
1918 predict_rs_update_time_ms(pending_cards) +
1919 predict_rs_scan_time_ms(card_num) +
1920 predict_object_copy_time_ms(bytes_to_copy) +
1921 predict_young_other_time_ms(young_num) +
1922 predict_constant_other_time_ms();
1923 }
1925 double
1926 G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards) {
1927 size_t rs_length = predict_rs_length_diff();
1928 size_t card_num;
1929 if (full_young_gcs())
1930 card_num = predict_young_card_num(rs_length);
1931 else
1932 card_num = predict_non_young_card_num(rs_length);
1933 return predict_base_elapsed_time_ms(pending_cards, card_num);
1934 }
1936 double
1937 G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards,
1938 size_t scanned_cards) {
1939 return
1940 predict_rs_update_time_ms(pending_cards) +
1941 predict_rs_scan_time_ms(scanned_cards) +
1942 predict_constant_other_time_ms();
1943 }
1945 double
1946 G1CollectorPolicy::predict_region_elapsed_time_ms(HeapRegion* hr,
1947 bool young) {
1948 size_t rs_length = hr->rem_set()->occupied();
1949 size_t card_num;
1950 if (full_young_gcs())
1951 card_num = predict_young_card_num(rs_length);
1952 else
1953 card_num = predict_non_young_card_num(rs_length);
1954 size_t bytes_to_copy = predict_bytes_to_copy(hr);
1956 double region_elapsed_time_ms =
1957 predict_rs_scan_time_ms(card_num) +
1958 predict_object_copy_time_ms(bytes_to_copy);
1960 if (young)
1961 region_elapsed_time_ms += predict_young_other_time_ms(1);
1962 else
1963 region_elapsed_time_ms += predict_non_young_other_time_ms(1);
1965 return region_elapsed_time_ms;
1966 }
1968 size_t
1969 G1CollectorPolicy::predict_bytes_to_copy(HeapRegion* hr) {
1970 size_t bytes_to_copy;
1971 if (hr->is_marked())
1972 bytes_to_copy = hr->max_live_bytes();
1973 else {
1974 guarantee( hr->is_young() && hr->age_in_surv_rate_group() != -1,
1975 "invariant" );
1976 int age = hr->age_in_surv_rate_group();
1977 double yg_surv_rate = predict_yg_surv_rate(age, hr->surv_rate_group());
1978 bytes_to_copy = (size_t) ((double) hr->used() * yg_surv_rate);
1979 }
1981 return bytes_to_copy;
1982 }
1984 void
1985 G1CollectorPolicy::start_recording_regions() {
1986 _recorded_rs_lengths = 0;
1987 _recorded_scan_only_regions = 0;
1988 _recorded_young_regions = 0;
1989 _recorded_non_young_regions = 0;
1991 #if PREDICTIONS_VERBOSE
1992 _predicted_rs_lengths = 0;
1993 _predicted_cards_scanned = 0;
1995 _recorded_marked_bytes = 0;
1996 _recorded_young_bytes = 0;
1997 _predicted_bytes_to_copy = 0;
1998 #endif // PREDICTIONS_VERBOSE
1999 }
2001 void
2002 G1CollectorPolicy::record_cset_region(HeapRegion* hr, bool young) {
2003 if (young) {
2004 ++_recorded_young_regions;
2005 } else {
2006 ++_recorded_non_young_regions;
2007 }
2008 #if PREDICTIONS_VERBOSE
2009 if (young) {
2010 _recorded_young_bytes += hr->used();
2011 } else {
2012 _recorded_marked_bytes += hr->max_live_bytes();
2013 }
2014 _predicted_bytes_to_copy += predict_bytes_to_copy(hr);
2015 #endif // PREDICTIONS_VERBOSE
2017 size_t rs_length = hr->rem_set()->occupied();
2018 _recorded_rs_lengths += rs_length;
2019 }
2021 void
2022 G1CollectorPolicy::record_scan_only_regions(size_t scan_only_length) {
2023 _recorded_scan_only_regions = scan_only_length;
2024 }
2026 void
2027 G1CollectorPolicy::end_recording_regions() {
2028 #if PREDICTIONS_VERBOSE
2029 _predicted_pending_cards = predict_pending_cards();
2030 _predicted_rs_lengths = _recorded_rs_lengths + predict_rs_length_diff();
2031 if (full_young_gcs())
2032 _predicted_cards_scanned += predict_young_card_num(_predicted_rs_lengths);
2033 else
2034 _predicted_cards_scanned +=
2035 predict_non_young_card_num(_predicted_rs_lengths);
2036 _recorded_region_num = _recorded_young_regions + _recorded_non_young_regions;
2038 _predicted_scan_only_scan_time_ms =
2039 predict_scan_only_time_ms(_recorded_scan_only_regions);
2040 _predicted_rs_update_time_ms =
2041 predict_rs_update_time_ms(_g1->pending_card_num());
2042 _predicted_rs_scan_time_ms =
2043 predict_rs_scan_time_ms(_predicted_cards_scanned);
2044 _predicted_object_copy_time_ms =
2045 predict_object_copy_time_ms(_predicted_bytes_to_copy);
2046 _predicted_constant_other_time_ms =
2047 predict_constant_other_time_ms();
2048 _predicted_young_other_time_ms =
2049 predict_young_other_time_ms(_recorded_young_regions);
2050 _predicted_non_young_other_time_ms =
2051 predict_non_young_other_time_ms(_recorded_non_young_regions);
2053 _predicted_pause_time_ms =
2054 _predicted_scan_only_scan_time_ms +
2055 _predicted_rs_update_time_ms +
2056 _predicted_rs_scan_time_ms +
2057 _predicted_object_copy_time_ms +
2058 _predicted_constant_other_time_ms +
2059 _predicted_young_other_time_ms +
2060 _predicted_non_young_other_time_ms;
2061 #endif // PREDICTIONS_VERBOSE
2062 }
2064 void G1CollectorPolicy::check_if_region_is_too_expensive(double
2065 predicted_time_ms) {
2066 // I don't think we need to do this when in young GC mode since
2067 // marking will be initiated next time we hit the soft limit anyway...
2068 if (predicted_time_ms > _expensive_region_limit_ms) {
2069 if (!in_young_gc_mode()) {
2070 set_full_young_gcs(true);
2071 _should_initiate_conc_mark = true;
2072 } else
2073 // no point in doing another partial one
2074 _should_revert_to_full_young_gcs = true;
2075 }
2076 }
2078 // </NEW PREDICTION>
2081 void G1CollectorPolicy::update_recent_gc_times(double end_time_sec,
2082 double elapsed_ms) {
2083 _recent_gc_times_ms->add(elapsed_ms);
2084 _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec);
2085 _prev_collection_pause_end_ms = end_time_sec * 1000.0;
2086 }
2088 double G1CollectorPolicy::recent_avg_time_for_pauses_ms() {
2089 if (_recent_pause_times_ms->num() == 0) return (double) MaxGCPauseMillis;
2090 else return _recent_pause_times_ms->avg();
2091 }
2093 double G1CollectorPolicy::recent_avg_time_for_CH_strong_ms() {
2094 if (_recent_CH_strong_roots_times_ms->num() == 0)
2095 return (double)MaxGCPauseMillis/3.0;
2096 else return _recent_CH_strong_roots_times_ms->avg();
2097 }
2099 double G1CollectorPolicy::recent_avg_time_for_G1_strong_ms() {
2100 if (_recent_G1_strong_roots_times_ms->num() == 0)
2101 return (double)MaxGCPauseMillis/3.0;
2102 else return _recent_G1_strong_roots_times_ms->avg();
2103 }
2105 double G1CollectorPolicy::recent_avg_time_for_evac_ms() {
2106 if (_recent_evac_times_ms->num() == 0) return (double)MaxGCPauseMillis/3.0;
2107 else return _recent_evac_times_ms->avg();
2108 }
2110 int G1CollectorPolicy::number_of_recent_gcs() {
2111 assert(_recent_CH_strong_roots_times_ms->num() ==
2112 _recent_G1_strong_roots_times_ms->num(), "Sequence out of sync");
2113 assert(_recent_G1_strong_roots_times_ms->num() ==
2114 _recent_evac_times_ms->num(), "Sequence out of sync");
2115 assert(_recent_evac_times_ms->num() ==
2116 _recent_pause_times_ms->num(), "Sequence out of sync");
2117 assert(_recent_pause_times_ms->num() ==
2118 _recent_CS_bytes_used_before->num(), "Sequence out of sync");
2119 assert(_recent_CS_bytes_used_before->num() ==
2120 _recent_CS_bytes_surviving->num(), "Sequence out of sync");
2121 return _recent_pause_times_ms->num();
2122 }
2124 double G1CollectorPolicy::recent_avg_survival_fraction() {
2125 return recent_avg_survival_fraction_work(_recent_CS_bytes_surviving,
2126 _recent_CS_bytes_used_before);
2127 }
2129 double G1CollectorPolicy::last_survival_fraction() {
2130 return last_survival_fraction_work(_recent_CS_bytes_surviving,
2131 _recent_CS_bytes_used_before);
2132 }
2134 double
2135 G1CollectorPolicy::recent_avg_survival_fraction_work(TruncatedSeq* surviving,
2136 TruncatedSeq* before) {
2137 assert(surviving->num() == before->num(), "Sequence out of sync");
2138 if (before->sum() > 0.0) {
2139 double recent_survival_rate = surviving->sum() / before->sum();
2140 // We exempt parallel collection from this check because Alloc Buffer
2141 // fragmentation can produce negative collections.
2142 // Further, we're now always doing parallel collection. But I'm still
2143 // leaving this here as a placeholder for a more precise assertion later.
2144 // (DLD, 10/05.)
2145 assert((true || ParallelGCThreads > 0) ||
2146 _g1->evacuation_failed() ||
2147 recent_survival_rate <= 1.0, "Or bad frac");
2148 return recent_survival_rate;
2149 } else {
2150 return 1.0; // Be conservative.
2151 }
2152 }
2154 double
2155 G1CollectorPolicy::last_survival_fraction_work(TruncatedSeq* surviving,
2156 TruncatedSeq* before) {
2157 assert(surviving->num() == before->num(), "Sequence out of sync");
2158 if (surviving->num() > 0 && before->last() > 0.0) {
2159 double last_survival_rate = surviving->last() / before->last();
2160 // We exempt parallel collection from this check because Alloc Buffer
2161 // fragmentation can produce negative collections.
2162 // Further, we're now always doing parallel collection. But I'm still
2163 // leaving this here as a placeholder for a more precise assertion later.
2164 // (DLD, 10/05.)
2165 assert((true || ParallelGCThreads > 0) ||
2166 last_survival_rate <= 1.0, "Or bad frac");
2167 return last_survival_rate;
2168 } else {
2169 return 1.0;
2170 }
2171 }
2173 static const int survival_min_obs = 5;
2174 static double survival_min_obs_limits[] = { 0.9, 0.7, 0.5, 0.3, 0.1 };
2175 static const double min_survival_rate = 0.1;
2177 double
2178 G1CollectorPolicy::conservative_avg_survival_fraction_work(double avg,
2179 double latest) {
2180 double res = avg;
2181 if (number_of_recent_gcs() < survival_min_obs) {
2182 res = MAX2(res, survival_min_obs_limits[number_of_recent_gcs()]);
2183 }
2184 res = MAX2(res, latest);
2185 res = MAX2(res, min_survival_rate);
2186 // In the parallel case, LAB fragmentation can produce "negative
2187 // collections"; so can evac failure. Cap at 1.0
2188 res = MIN2(res, 1.0);
2189 return res;
2190 }
2192 size_t G1CollectorPolicy::expansion_amount() {
2193 if ((int)(recent_avg_pause_time_ratio() * 100.0) > G1GCPercent) {
2194 // We will double the existing space, or take
2195 // G1ExpandByPercentOfAvailable % of the available expansion
2196 // space, whichever is smaller, bounded below by a minimum
2197 // expansion (unless that's all that's left.)
2198 const size_t min_expand_bytes = 1*M;
2199 size_t reserved_bytes = _g1->g1_reserved_obj_bytes();
2200 size_t committed_bytes = _g1->capacity();
2201 size_t uncommitted_bytes = reserved_bytes - committed_bytes;
2202 size_t expand_bytes;
2203 size_t expand_bytes_via_pct =
2204 uncommitted_bytes * G1ExpandByPercentOfAvailable / 100;
2205 expand_bytes = MIN2(expand_bytes_via_pct, committed_bytes);
2206 expand_bytes = MAX2(expand_bytes, min_expand_bytes);
2207 expand_bytes = MIN2(expand_bytes, uncommitted_bytes);
2208 if (G1PolicyVerbose > 1) {
2209 gclog_or_tty->print("Decided to expand: ratio = %5.2f, "
2210 "committed = %d%s, uncommited = %d%s, via pct = %d%s.\n"
2211 " Answer = %d.\n",
2212 recent_avg_pause_time_ratio(),
2213 byte_size_in_proper_unit(committed_bytes),
2214 proper_unit_for_byte_size(committed_bytes),
2215 byte_size_in_proper_unit(uncommitted_bytes),
2216 proper_unit_for_byte_size(uncommitted_bytes),
2217 byte_size_in_proper_unit(expand_bytes_via_pct),
2218 proper_unit_for_byte_size(expand_bytes_via_pct),
2219 byte_size_in_proper_unit(expand_bytes),
2220 proper_unit_for_byte_size(expand_bytes));
2221 }
2222 return expand_bytes;
2223 } else {
2224 return 0;
2225 }
2226 }
2228 void G1CollectorPolicy::note_start_of_mark_thread() {
2229 _mark_thread_startup_sec = os::elapsedTime();
2230 }
2232 class CountCSClosure: public HeapRegionClosure {
2233 G1CollectorPolicy* _g1_policy;
2234 public:
2235 CountCSClosure(G1CollectorPolicy* g1_policy) :
2236 _g1_policy(g1_policy) {}
2237 bool doHeapRegion(HeapRegion* r) {
2238 _g1_policy->_bytes_in_collection_set_before_gc += r->used();
2239 return false;
2240 }
2241 };
2243 void G1CollectorPolicy::count_CS_bytes_used() {
2244 CountCSClosure cs_closure(this);
2245 _g1->collection_set_iterate(&cs_closure);
2246 }
2248 static void print_indent(int level) {
2249 for (int j = 0; j < level+1; ++j)
2250 gclog_or_tty->print(" ");
2251 }
2253 void G1CollectorPolicy::print_summary (int level,
2254 const char* str,
2255 NumberSeq* seq) const {
2256 double sum = seq->sum();
2257 print_indent(level);
2258 gclog_or_tty->print_cr("%-24s = %8.2lf s (avg = %8.2lf ms)",
2259 str, sum / 1000.0, seq->avg());
2260 }
2262 void G1CollectorPolicy::print_summary_sd (int level,
2263 const char* str,
2264 NumberSeq* seq) const {
2265 print_summary(level, str, seq);
2266 print_indent(level + 5);
2267 gclog_or_tty->print_cr("(num = %5d, std dev = %8.2lf ms, max = %8.2lf ms)",
2268 seq->num(), seq->sd(), seq->maximum());
2269 }
2271 void G1CollectorPolicy::check_other_times(int level,
2272 NumberSeq* other_times_ms,
2273 NumberSeq* calc_other_times_ms) const {
2274 bool should_print = false;
2276 double max_sum = MAX2(fabs(other_times_ms->sum()),
2277 fabs(calc_other_times_ms->sum()));
2278 double min_sum = MIN2(fabs(other_times_ms->sum()),
2279 fabs(calc_other_times_ms->sum()));
2280 double sum_ratio = max_sum / min_sum;
2281 if (sum_ratio > 1.1) {
2282 should_print = true;
2283 print_indent(level + 1);
2284 gclog_or_tty->print_cr("## CALCULATED OTHER SUM DOESN'T MATCH RECORDED ###");
2285 }
2287 double max_avg = MAX2(fabs(other_times_ms->avg()),
2288 fabs(calc_other_times_ms->avg()));
2289 double min_avg = MIN2(fabs(other_times_ms->avg()),
2290 fabs(calc_other_times_ms->avg()));
2291 double avg_ratio = max_avg / min_avg;
2292 if (avg_ratio > 1.1) {
2293 should_print = true;
2294 print_indent(level + 1);
2295 gclog_or_tty->print_cr("## CALCULATED OTHER AVG DOESN'T MATCH RECORDED ###");
2296 }
2298 if (other_times_ms->sum() < -0.01) {
2299 print_indent(level + 1);
2300 gclog_or_tty->print_cr("## RECORDED OTHER SUM IS NEGATIVE ###");
2301 }
2303 if (other_times_ms->avg() < -0.01) {
2304 print_indent(level + 1);
2305 gclog_or_tty->print_cr("## RECORDED OTHER AVG IS NEGATIVE ###");
2306 }
2308 if (calc_other_times_ms->sum() < -0.01) {
2309 should_print = true;
2310 print_indent(level + 1);
2311 gclog_or_tty->print_cr("## CALCULATED OTHER SUM IS NEGATIVE ###");
2312 }
2314 if (calc_other_times_ms->avg() < -0.01) {
2315 should_print = true;
2316 print_indent(level + 1);
2317 gclog_or_tty->print_cr("## CALCULATED OTHER AVG IS NEGATIVE ###");
2318 }
2320 if (should_print)
2321 print_summary(level, "Other(Calc)", calc_other_times_ms);
2322 }
2324 void G1CollectorPolicy::print_summary(PauseSummary* summary) const {
2325 bool parallel = ParallelGCThreads > 0;
2326 MainBodySummary* body_summary = summary->main_body_summary();
2327 if (summary->get_total_seq()->num() > 0) {
2328 print_summary_sd(0, "Evacuation Pauses", summary->get_total_seq());
2329 if (body_summary != NULL) {
2330 print_summary(1, "SATB Drain", body_summary->get_satb_drain_seq());
2331 if (parallel) {
2332 print_summary(1, "Parallel Time", body_summary->get_parallel_seq());
2333 print_summary(2, "Update RS", body_summary->get_update_rs_seq());
2334 print_summary(2, "Ext Root Scanning",
2335 body_summary->get_ext_root_scan_seq());
2336 print_summary(2, "Mark Stack Scanning",
2337 body_summary->get_mark_stack_scan_seq());
2338 print_summary(2, "Scan-Only Scanning",
2339 body_summary->get_scan_only_seq());
2340 print_summary(2, "Scan RS", body_summary->get_scan_rs_seq());
2341 print_summary(2, "Object Copy", body_summary->get_obj_copy_seq());
2342 print_summary(2, "Termination", body_summary->get_termination_seq());
2343 print_summary(2, "Other", body_summary->get_parallel_other_seq());
2344 {
2345 NumberSeq* other_parts[] = {
2346 body_summary->get_update_rs_seq(),
2347 body_summary->get_ext_root_scan_seq(),
2348 body_summary->get_mark_stack_scan_seq(),
2349 body_summary->get_scan_only_seq(),
2350 body_summary->get_scan_rs_seq(),
2351 body_summary->get_obj_copy_seq(),
2352 body_summary->get_termination_seq()
2353 };
2354 NumberSeq calc_other_times_ms(body_summary->get_parallel_seq(),
2355 7, other_parts);
2356 check_other_times(2, body_summary->get_parallel_other_seq(),
2357 &calc_other_times_ms);
2358 }
2359 print_summary(1, "Mark Closure", body_summary->get_mark_closure_seq());
2360 print_summary(1, "Clear CT", body_summary->get_clear_ct_seq());
2361 } else {
2362 print_summary(1, "Update RS", body_summary->get_update_rs_seq());
2363 print_summary(1, "Ext Root Scanning",
2364 body_summary->get_ext_root_scan_seq());
2365 print_summary(1, "Mark Stack Scanning",
2366 body_summary->get_mark_stack_scan_seq());
2367 print_summary(1, "Scan-Only Scanning",
2368 body_summary->get_scan_only_seq());
2369 print_summary(1, "Scan RS", body_summary->get_scan_rs_seq());
2370 print_summary(1, "Object Copy", body_summary->get_obj_copy_seq());
2371 }
2372 }
2373 print_summary(1, "Other", summary->get_other_seq());
2374 {
2375 NumberSeq calc_other_times_ms;
2376 if (body_summary != NULL) {
2377 // not abandoned
2378 if (parallel) {
2379 // parallel
2380 NumberSeq* other_parts[] = {
2381 body_summary->get_satb_drain_seq(),
2382 body_summary->get_parallel_seq(),
2383 body_summary->get_clear_ct_seq()
2384 };
2385 calc_other_times_ms = NumberSeq(summary->get_total_seq(),
2386 3, other_parts);
2387 } else {
2388 // serial
2389 NumberSeq* other_parts[] = {
2390 body_summary->get_satb_drain_seq(),
2391 body_summary->get_update_rs_seq(),
2392 body_summary->get_ext_root_scan_seq(),
2393 body_summary->get_mark_stack_scan_seq(),
2394 body_summary->get_scan_only_seq(),
2395 body_summary->get_scan_rs_seq(),
2396 body_summary->get_obj_copy_seq()
2397 };
2398 calc_other_times_ms = NumberSeq(summary->get_total_seq(),
2399 7, other_parts);
2400 }
2401 } else {
2402 // abandoned
2403 calc_other_times_ms = NumberSeq();
2404 }
2405 check_other_times(1, summary->get_other_seq(), &calc_other_times_ms);
2406 }
2407 } else {
2408 print_indent(0);
2409 gclog_or_tty->print_cr("none");
2410 }
2411 gclog_or_tty->print_cr("");
2412 }
2414 void
2415 G1CollectorPolicy::print_abandoned_summary(PauseSummary* summary) const {
2416 bool printed = false;
2417 if (summary->get_total_seq()->num() > 0) {
2418 printed = true;
2419 print_summary(summary);
2420 }
2421 if (!printed) {
2422 print_indent(0);
2423 gclog_or_tty->print_cr("none");
2424 gclog_or_tty->print_cr("");
2425 }
2426 }
2428 void G1CollectorPolicy::print_tracing_info() const {
2429 if (TraceGen0Time) {
2430 gclog_or_tty->print_cr("ALL PAUSES");
2431 print_summary_sd(0, "Total", _all_pause_times_ms);
2432 gclog_or_tty->print_cr("");
2433 gclog_or_tty->print_cr("");
2434 gclog_or_tty->print_cr(" Full Young GC Pauses: %8d", _full_young_pause_num);
2435 gclog_or_tty->print_cr(" Partial Young GC Pauses: %8d", _partial_young_pause_num);
2436 gclog_or_tty->print_cr("");
2438 gclog_or_tty->print_cr("EVACUATION PAUSES");
2439 print_summary(_summary);
2441 gclog_or_tty->print_cr("ABANDONED PAUSES");
2442 print_abandoned_summary(_abandoned_summary);
2444 gclog_or_tty->print_cr("MISC");
2445 print_summary_sd(0, "Stop World", _all_stop_world_times_ms);
2446 print_summary_sd(0, "Yields", _all_yield_times_ms);
2447 for (int i = 0; i < _aux_num; ++i) {
2448 if (_all_aux_times_ms[i].num() > 0) {
2449 char buffer[96];
2450 sprintf(buffer, "Aux%d", i);
2451 print_summary_sd(0, buffer, &_all_aux_times_ms[i]);
2452 }
2453 }
2455 size_t all_region_num = _region_num_young + _region_num_tenured;
2456 gclog_or_tty->print_cr(" New Regions %8d, Young %8d (%6.2lf%%), "
2457 "Tenured %8d (%6.2lf%%)",
2458 all_region_num,
2459 _region_num_young,
2460 (double) _region_num_young / (double) all_region_num * 100.0,
2461 _region_num_tenured,
2462 (double) _region_num_tenured / (double) all_region_num * 100.0);
2463 }
2464 if (TraceGen1Time) {
2465 if (_all_full_gc_times_ms->num() > 0) {
2466 gclog_or_tty->print("\n%4d full_gcs: total time = %8.2f s",
2467 _all_full_gc_times_ms->num(),
2468 _all_full_gc_times_ms->sum() / 1000.0);
2469 gclog_or_tty->print_cr(" (avg = %8.2fms).", _all_full_gc_times_ms->avg());
2470 gclog_or_tty->print_cr(" [std. dev = %8.2f ms, max = %8.2f ms]",
2471 _all_full_gc_times_ms->sd(),
2472 _all_full_gc_times_ms->maximum());
2473 }
2474 }
2475 }
2477 void G1CollectorPolicy::print_yg_surv_rate_info() const {
2478 #ifndef PRODUCT
2479 _short_lived_surv_rate_group->print_surv_rate_summary();
2480 // add this call for any other surv rate groups
2481 #endif // PRODUCT
2482 }
2484 bool
2485 G1CollectorPolicy::should_add_next_region_to_young_list() {
2486 assert(in_young_gc_mode(), "should be in young GC mode");
2487 bool ret;
2488 size_t young_list_length = _g1->young_list_length();
2489 size_t young_list_max_length = _young_list_target_length;
2490 if (G1FixedEdenSize) {
2491 young_list_max_length -= _max_survivor_regions;
2492 }
2493 if (young_list_length < young_list_max_length) {
2494 ret = true;
2495 ++_region_num_young;
2496 } else {
2497 ret = false;
2498 ++_region_num_tenured;
2499 }
2501 return ret;
2502 }
2504 #ifndef PRODUCT
2505 // for debugging, bit of a hack...
2506 static char*
2507 region_num_to_mbs(int length) {
2508 static char buffer[64];
2509 double bytes = (double) (length * HeapRegion::GrainBytes);
2510 double mbs = bytes / (double) (1024 * 1024);
2511 sprintf(buffer, "%7.2lfMB", mbs);
2512 return buffer;
2513 }
2514 #endif // PRODUCT
2516 void
2517 G1CollectorPolicy::checkpoint_conc_overhead() {
2518 double conc_overhead = 0.0;
2519 if (G1AccountConcurrentOverhead)
2520 conc_overhead = COTracker::totalPredConcOverhead();
2521 _mmu_tracker->update_conc_overhead(conc_overhead);
2522 #if 0
2523 gclog_or_tty->print(" CO %1.4lf TARGET %1.4lf",
2524 conc_overhead, _mmu_tracker->max_gc_time());
2525 #endif
2526 }
2529 size_t G1CollectorPolicy::max_regions(int purpose) {
2530 switch (purpose) {
2531 case GCAllocForSurvived:
2532 return _max_survivor_regions;
2533 case GCAllocForTenured:
2534 return REGIONS_UNLIMITED;
2535 default:
2536 ShouldNotReachHere();
2537 return REGIONS_UNLIMITED;
2538 };
2539 }
2541 // Calculates survivor space parameters.
2542 void G1CollectorPolicy::calculate_survivors_policy()
2543 {
2544 if (!G1UseSurvivorSpaces) {
2545 return;
2546 }
2547 if (G1FixedSurvivorSpaceSize == 0) {
2548 _max_survivor_regions = _young_list_target_length / SurvivorRatio;
2549 } else {
2550 _max_survivor_regions = G1FixedSurvivorSpaceSize / HeapRegion::GrainBytes;
2551 }
2553 if (G1FixedTenuringThreshold) {
2554 _tenuring_threshold = MaxTenuringThreshold;
2555 } else {
2556 _tenuring_threshold = _survivors_age_table.compute_tenuring_threshold(
2557 HeapRegion::GrainWords * _max_survivor_regions);
2558 }
2559 }
2561 bool
2562 G1CollectorPolicy_BestRegionsFirst::should_do_collection_pause(size_t
2563 word_size) {
2564 assert(_g1->regions_accounted_for(), "Region leakage!");
2565 // Initiate a pause when we reach the steady-state "used" target.
2566 size_t used_hard = (_g1->capacity() / 100) * G1SteadyStateUsed;
2567 size_t used_soft =
2568 MAX2((_g1->capacity() / 100) * (G1SteadyStateUsed - G1SteadyStateUsedDelta),
2569 used_hard/2);
2570 size_t used = _g1->used();
2572 double max_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
2574 size_t young_list_length = _g1->young_list_length();
2575 size_t young_list_max_length = _young_list_target_length;
2576 if (G1FixedEdenSize) {
2577 young_list_max_length -= _max_survivor_regions;
2578 }
2579 bool reached_target_length = young_list_length >= young_list_max_length;
2581 if (in_young_gc_mode()) {
2582 if (reached_target_length) {
2583 assert( young_list_length > 0 && _g1->young_list_length() > 0,
2584 "invariant" );
2585 _target_pause_time_ms = max_pause_time_ms;
2586 return true;
2587 }
2588 } else {
2589 guarantee( false, "should not reach here" );
2590 }
2592 return false;
2593 }
2595 #ifndef PRODUCT
2596 class HRSortIndexIsOKClosure: public HeapRegionClosure {
2597 CollectionSetChooser* _chooser;
2598 public:
2599 HRSortIndexIsOKClosure(CollectionSetChooser* chooser) :
2600 _chooser(chooser) {}
2602 bool doHeapRegion(HeapRegion* r) {
2603 if (!r->continuesHumongous()) {
2604 assert(_chooser->regionProperlyOrdered(r), "Ought to be.");
2605 }
2606 return false;
2607 }
2608 };
2610 bool G1CollectorPolicy_BestRegionsFirst::assertMarkedBytesDataOK() {
2611 HRSortIndexIsOKClosure cl(_collectionSetChooser);
2612 _g1->heap_region_iterate(&cl);
2613 return true;
2614 }
2615 #endif
2617 void
2618 G1CollectorPolicy_BestRegionsFirst::
2619 record_collection_pause_start(double start_time_sec, size_t start_used) {
2620 G1CollectorPolicy::record_collection_pause_start(start_time_sec, start_used);
2621 }
2623 class NextNonCSElemFinder: public HeapRegionClosure {
2624 HeapRegion* _res;
2625 public:
2626 NextNonCSElemFinder(): _res(NULL) {}
2627 bool doHeapRegion(HeapRegion* r) {
2628 if (!r->in_collection_set()) {
2629 _res = r;
2630 return true;
2631 } else {
2632 return false;
2633 }
2634 }
2635 HeapRegion* res() { return _res; }
2636 };
2638 class KnownGarbageClosure: public HeapRegionClosure {
2639 CollectionSetChooser* _hrSorted;
2641 public:
2642 KnownGarbageClosure(CollectionSetChooser* hrSorted) :
2643 _hrSorted(hrSorted)
2644 {}
2646 bool doHeapRegion(HeapRegion* r) {
2647 // We only include humongous regions in collection
2648 // sets when concurrent mark shows that their contained object is
2649 // unreachable.
2651 // Do we have any marking information for this region?
2652 if (r->is_marked()) {
2653 // We don't include humongous regions in collection
2654 // sets because we collect them immediately at the end of a marking
2655 // cycle. We also don't include young regions because we *must*
2656 // include them in the next collection pause.
2657 if (!r->isHumongous() && !r->is_young()) {
2658 _hrSorted->addMarkedHeapRegion(r);
2659 }
2660 }
2661 return false;
2662 }
2663 };
2665 class ParKnownGarbageHRClosure: public HeapRegionClosure {
2666 CollectionSetChooser* _hrSorted;
2667 jint _marked_regions_added;
2668 jint _chunk_size;
2669 jint _cur_chunk_idx;
2670 jint _cur_chunk_end; // Cur chunk [_cur_chunk_idx, _cur_chunk_end)
2671 int _worker;
2672 int _invokes;
2674 void get_new_chunk() {
2675 _cur_chunk_idx = _hrSorted->getParMarkedHeapRegionChunk(_chunk_size);
2676 _cur_chunk_end = _cur_chunk_idx + _chunk_size;
2677 }
2678 void add_region(HeapRegion* r) {
2679 if (_cur_chunk_idx == _cur_chunk_end) {
2680 get_new_chunk();
2681 }
2682 assert(_cur_chunk_idx < _cur_chunk_end, "postcondition");
2683 _hrSorted->setMarkedHeapRegion(_cur_chunk_idx, r);
2684 _marked_regions_added++;
2685 _cur_chunk_idx++;
2686 }
2688 public:
2689 ParKnownGarbageHRClosure(CollectionSetChooser* hrSorted,
2690 jint chunk_size,
2691 int worker) :
2692 _hrSorted(hrSorted), _chunk_size(chunk_size), _worker(worker),
2693 _marked_regions_added(0), _cur_chunk_idx(0), _cur_chunk_end(0),
2694 _invokes(0)
2695 {}
2697 bool doHeapRegion(HeapRegion* r) {
2698 // We only include humongous regions in collection
2699 // sets when concurrent mark shows that their contained object is
2700 // unreachable.
2701 _invokes++;
2703 // Do we have any marking information for this region?
2704 if (r->is_marked()) {
2705 // We don't include humongous regions in collection
2706 // sets because we collect them immediately at the end of a marking
2707 // cycle.
2708 // We also do not include young regions in collection sets
2709 if (!r->isHumongous() && !r->is_young()) {
2710 add_region(r);
2711 }
2712 }
2713 return false;
2714 }
2715 jint marked_regions_added() { return _marked_regions_added; }
2716 int invokes() { return _invokes; }
2717 };
2719 class ParKnownGarbageTask: public AbstractGangTask {
2720 CollectionSetChooser* _hrSorted;
2721 jint _chunk_size;
2722 G1CollectedHeap* _g1;
2723 public:
2724 ParKnownGarbageTask(CollectionSetChooser* hrSorted, jint chunk_size) :
2725 AbstractGangTask("ParKnownGarbageTask"),
2726 _hrSorted(hrSorted), _chunk_size(chunk_size),
2727 _g1(G1CollectedHeap::heap())
2728 {}
2730 void work(int i) {
2731 ParKnownGarbageHRClosure parKnownGarbageCl(_hrSorted, _chunk_size, i);
2732 // Back to zero for the claim value.
2733 _g1->heap_region_par_iterate_chunked(&parKnownGarbageCl, i,
2734 HeapRegion::InitialClaimValue);
2735 jint regions_added = parKnownGarbageCl.marked_regions_added();
2736 _hrSorted->incNumMarkedHeapRegions(regions_added);
2737 if (G1PrintParCleanupStats) {
2738 gclog_or_tty->print(" Thread %d called %d times, added %d regions to list.\n",
2739 i, parKnownGarbageCl.invokes(), regions_added);
2740 }
2741 }
2742 };
2744 void
2745 G1CollectorPolicy_BestRegionsFirst::
2746 record_concurrent_mark_cleanup_end(size_t freed_bytes,
2747 size_t max_live_bytes) {
2748 double start;
2749 if (G1PrintParCleanupStats) start = os::elapsedTime();
2750 record_concurrent_mark_cleanup_end_work1(freed_bytes, max_live_bytes);
2752 _collectionSetChooser->clearMarkedHeapRegions();
2753 double clear_marked_end;
2754 if (G1PrintParCleanupStats) {
2755 clear_marked_end = os::elapsedTime();
2756 gclog_or_tty->print_cr(" clear marked regions + work1: %8.3f ms.",
2757 (clear_marked_end - start)*1000.0);
2758 }
2759 if (ParallelGCThreads > 0) {
2760 const size_t OverpartitionFactor = 4;
2761 const size_t MinChunkSize = 8;
2762 const size_t ChunkSize =
2763 MAX2(_g1->n_regions() / (ParallelGCThreads * OverpartitionFactor),
2764 MinChunkSize);
2765 _collectionSetChooser->prepareForAddMarkedHeapRegionsPar(_g1->n_regions(),
2766 ChunkSize);
2767 ParKnownGarbageTask parKnownGarbageTask(_collectionSetChooser,
2768 (int) ChunkSize);
2769 _g1->workers()->run_task(&parKnownGarbageTask);
2771 assert(_g1->check_heap_region_claim_values(HeapRegion::InitialClaimValue),
2772 "sanity check");
2773 } else {
2774 KnownGarbageClosure knownGarbagecl(_collectionSetChooser);
2775 _g1->heap_region_iterate(&knownGarbagecl);
2776 }
2777 double known_garbage_end;
2778 if (G1PrintParCleanupStats) {
2779 known_garbage_end = os::elapsedTime();
2780 gclog_or_tty->print_cr(" compute known garbage: %8.3f ms.",
2781 (known_garbage_end - clear_marked_end)*1000.0);
2782 }
2783 _collectionSetChooser->sortMarkedHeapRegions();
2784 double sort_end;
2785 if (G1PrintParCleanupStats) {
2786 sort_end = os::elapsedTime();
2787 gclog_or_tty->print_cr(" sorting: %8.3f ms.",
2788 (sort_end - known_garbage_end)*1000.0);
2789 }
2791 record_concurrent_mark_cleanup_end_work2();
2792 double work2_end;
2793 if (G1PrintParCleanupStats) {
2794 work2_end = os::elapsedTime();
2795 gclog_or_tty->print_cr(" work2: %8.3f ms.",
2796 (work2_end - sort_end)*1000.0);
2797 }
2798 }
2800 // Add the heap region to the collection set and return the conservative
2801 // estimate of the number of live bytes.
2802 void G1CollectorPolicy::
2803 add_to_collection_set(HeapRegion* hr) {
2804 if (G1PrintRegions) {
2805 gclog_or_tty->print_cr("added region to cset %d:["PTR_FORMAT", "PTR_FORMAT"], "
2806 "top "PTR_FORMAT", young %s",
2807 hr->hrs_index(), hr->bottom(), hr->end(),
2808 hr->top(), (hr->is_young()) ? "YES" : "NO");
2809 }
2811 if (_g1->mark_in_progress())
2812 _g1->concurrent_mark()->registerCSetRegion(hr);
2814 assert(!hr->in_collection_set(),
2815 "should not already be in the CSet");
2816 hr->set_in_collection_set(true);
2817 hr->set_next_in_collection_set(_collection_set);
2818 _collection_set = hr;
2819 _collection_set_size++;
2820 _collection_set_bytes_used_before += hr->used();
2821 _g1->register_region_with_in_cset_fast_test(hr);
2822 }
2824 void
2825 G1CollectorPolicy_BestRegionsFirst::
2826 choose_collection_set() {
2827 double non_young_start_time_sec;
2828 start_recording_regions();
2830 guarantee(_target_pause_time_ms > -1.0,
2831 "_target_pause_time_ms should have been set!");
2832 assert(_collection_set == NULL, "Precondition");
2834 double base_time_ms = predict_base_elapsed_time_ms(_pending_cards);
2835 double predicted_pause_time_ms = base_time_ms;
2837 double target_time_ms = _target_pause_time_ms;
2838 double time_remaining_ms = target_time_ms - base_time_ms;
2840 // the 10% and 50% values are arbitrary...
2841 if (time_remaining_ms < 0.10*target_time_ms) {
2842 time_remaining_ms = 0.50 * target_time_ms;
2843 _within_target = false;
2844 } else {
2845 _within_target = true;
2846 }
2848 // We figure out the number of bytes available for future to-space.
2849 // For new regions without marking information, we must assume the
2850 // worst-case of complete survival. If we have marking information for a
2851 // region, we can bound the amount of live data. We can add a number of
2852 // such regions, as long as the sum of the live data bounds does not
2853 // exceed the available evacuation space.
2854 size_t max_live_bytes = _g1->free_regions() * HeapRegion::GrainBytes;
2856 size_t expansion_bytes =
2857 _g1->expansion_regions() * HeapRegion::GrainBytes;
2859 _collection_set_bytes_used_before = 0;
2860 _collection_set_size = 0;
2862 // Adjust for expansion and slop.
2863 max_live_bytes = max_live_bytes + expansion_bytes;
2865 assert(_g1->regions_accounted_for(), "Region leakage!");
2867 HeapRegion* hr;
2868 if (in_young_gc_mode()) {
2869 double young_start_time_sec = os::elapsedTime();
2871 if (G1PolicyVerbose > 0) {
2872 gclog_or_tty->print_cr("Adding %d young regions to the CSet",
2873 _g1->young_list_length());
2874 }
2875 _young_cset_length = 0;
2876 _last_young_gc_full = full_young_gcs() ? true : false;
2877 if (_last_young_gc_full)
2878 ++_full_young_pause_num;
2879 else
2880 ++_partial_young_pause_num;
2881 hr = _g1->pop_region_from_young_list();
2882 while (hr != NULL) {
2884 assert( hr->young_index_in_cset() == -1, "invariant" );
2885 assert( hr->age_in_surv_rate_group() != -1, "invariant" );
2886 hr->set_young_index_in_cset((int) _young_cset_length);
2888 ++_young_cset_length;
2889 double predicted_time_ms = predict_region_elapsed_time_ms(hr, true);
2890 time_remaining_ms -= predicted_time_ms;
2891 predicted_pause_time_ms += predicted_time_ms;
2892 assert(!hr->in_collection_set(), "invariant");
2893 add_to_collection_set(hr);
2894 record_cset_region(hr, true);
2895 max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes);
2896 if (G1PolicyVerbose > 0) {
2897 gclog_or_tty->print_cr(" Added [" PTR_FORMAT ", " PTR_FORMAT") to CS.",
2898 hr->bottom(), hr->end());
2899 gclog_or_tty->print_cr(" (" SIZE_FORMAT " KB left in heap.)",
2900 max_live_bytes/K);
2901 }
2902 hr = _g1->pop_region_from_young_list();
2903 }
2905 record_scan_only_regions(_g1->young_list_scan_only_length());
2907 double young_end_time_sec = os::elapsedTime();
2908 _recorded_young_cset_choice_time_ms =
2909 (young_end_time_sec - young_start_time_sec) * 1000.0;
2911 non_young_start_time_sec = os::elapsedTime();
2913 if (_young_cset_length > 0 && _last_young_gc_full) {
2914 // don't bother adding more regions...
2915 goto choose_collection_set_end;
2916 }
2917 }
2919 if (!in_young_gc_mode() || !full_young_gcs()) {
2920 bool should_continue = true;
2921 NumberSeq seq;
2922 double avg_prediction = 100000000000000000.0; // something very large
2923 do {
2924 hr = _collectionSetChooser->getNextMarkedRegion(time_remaining_ms,
2925 avg_prediction);
2926 if (hr != NULL) {
2927 double predicted_time_ms = predict_region_elapsed_time_ms(hr, false);
2928 time_remaining_ms -= predicted_time_ms;
2929 predicted_pause_time_ms += predicted_time_ms;
2930 add_to_collection_set(hr);
2931 record_cset_region(hr, false);
2932 max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes);
2933 if (G1PolicyVerbose > 0) {
2934 gclog_or_tty->print_cr(" (" SIZE_FORMAT " KB left in heap.)",
2935 max_live_bytes/K);
2936 }
2937 seq.add(predicted_time_ms);
2938 avg_prediction = seq.avg() + seq.sd();
2939 }
2940 should_continue =
2941 ( hr != NULL) &&
2942 ( (adaptive_young_list_length()) ? time_remaining_ms > 0.0
2943 : _collection_set_size < _young_list_fixed_length );
2944 } while (should_continue);
2946 if (!adaptive_young_list_length() &&
2947 _collection_set_size < _young_list_fixed_length)
2948 _should_revert_to_full_young_gcs = true;
2949 }
2951 choose_collection_set_end:
2952 count_CS_bytes_used();
2954 end_recording_regions();
2956 double non_young_end_time_sec = os::elapsedTime();
2957 _recorded_non_young_cset_choice_time_ms =
2958 (non_young_end_time_sec - non_young_start_time_sec) * 1000.0;
2959 }
2961 void G1CollectorPolicy_BestRegionsFirst::record_full_collection_end() {
2962 G1CollectorPolicy::record_full_collection_end();
2963 _collectionSetChooser->updateAfterFullCollection();
2964 }
2966 void G1CollectorPolicy_BestRegionsFirst::
2967 expand_if_possible(size_t numRegions) {
2968 size_t expansion_bytes = numRegions * HeapRegion::GrainBytes;
2969 _g1->expand(expansion_bytes);
2970 }
2972 void G1CollectorPolicy_BestRegionsFirst::
2973 record_collection_pause_end(bool abandoned) {
2974 G1CollectorPolicy::record_collection_pause_end(abandoned);
2975 assert(assertMarkedBytesDataOK(), "Marked regions not OK at pause end.");
2976 }
2978 // Local Variables: ***
2979 // c-indentation-style: gnu ***
2980 // End: ***