1 /*
2 * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/g1/concurrentG1Refine.hpp"
27 #include "gc/g1/concurrentMark.hpp"
28 #include "gc/g1/concurrentMarkThread.inline.hpp"
29 #include "gc/g1/g1CollectedHeap.inline.hpp"
30 #include "gc/g1/g1CollectorPolicy.hpp"
31 #include "gc/g1/g1GCPhaseTimes.hpp"
32 #include "gc/g1/heapRegion.inline.hpp"
33 #include "gc/g1/heapRegionRemSet.hpp"
34 #include "gc/shared/gcPolicyCounters.hpp"
35 #include "logging/log.hpp"
36 #include "runtime/arguments.hpp"
37 #include "runtime/java.hpp"
38 #include "runtime/mutexLocker.hpp"
39 #include "utilities/debug.hpp"
40
41 // Different defaults for different number of GC threads
42 // They were chosen by running GCOld and SPECjbb on debris with different
43 // numbers of GC threads and choosing them based on the results
44
45 // all the same
46 static double rs_length_diff_defaults[] = {
47 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
48 };
49
50 static double cost_per_card_ms_defaults[] = {
51 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015
52 };
53
54 // all the same
55 static double young_cards_per_entry_ratio_defaults[] = {
56 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
57 };
58
59 static double cost_per_entry_ms_defaults[] = {
60 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005
61 };
62
63 static double cost_per_byte_ms_defaults[] = {
64 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009
65 };
66
67 // these should be pretty consistent
68 static double constant_other_time_ms_defaults[] = {
69 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0
70 };
71
72
73 static double young_other_cost_per_region_ms_defaults[] = {
74 0.3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1
75 };
76
77 static double non_young_other_cost_per_region_ms_defaults[] = {
78 1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30
79 };
80
81 G1CollectorPolicy::G1CollectorPolicy() :
82 _predictor(G1ConfidencePercent / 100.0),
83 _parallel_gc_threads(ParallelGCThreads),
84
85 _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
86 _stop_world_start(0.0),
87
88 _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
89 _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
90
91 _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
92 _prev_collection_pause_end_ms(0.0),
93 _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
94 _cost_per_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
95 _cost_scan_hcc_seq(new TruncatedSeq(TruncatedSeqLength)),
96 _young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
97 _mixed_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
98 _cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
99 _mixed_cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
100 _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
101 _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
102 _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
103 _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
104 _non_young_other_cost_per_region_ms_seq(
105 new TruncatedSeq(TruncatedSeqLength)),
106
107 _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
108 _rs_lengths_seq(new TruncatedSeq(TruncatedSeqLength)),
109
110 _pause_time_target_ms((double) MaxGCPauseMillis),
111
112 _recent_prev_end_times_for_all_gcs_sec(
113 new TruncatedSeq(NumPrevPausesForHeuristics)),
114
115 _recent_avg_pause_time_ratio(0.0),
116 _rs_lengths_prediction(0),
117 _max_survivor_regions(0),
118
119 _eden_used_bytes_before_gc(0),
120 _survivor_used_bytes_before_gc(0),
121 _old_used_bytes_before_gc(0),
122 _heap_used_bytes_before_gc(0),
123 _metaspace_used_bytes_before_gc(0),
124 _eden_capacity_bytes_before_gc(0),
125 _heap_capacity_bytes_before_gc(0),
126
127 _eden_cset_region_length(0),
128 _survivor_cset_region_length(0),
129 _old_cset_region_length(0),
130
131 _collection_set(NULL),
132 _collection_set_bytes_used_before(0),
133
134 // Incremental CSet attributes
135 _inc_cset_build_state(Inactive),
136 _inc_cset_head(NULL),
137 _inc_cset_tail(NULL),
138 _inc_cset_bytes_used_before(0),
139 _inc_cset_max_finger(NULL),
140 _inc_cset_recorded_rs_lengths(0),
141 _inc_cset_recorded_rs_lengths_diffs(0),
142 _inc_cset_predicted_elapsed_time_ms(0.0),
143 _inc_cset_predicted_elapsed_time_ms_diffs(0.0),
144
145 // add here any more surv rate groups
146 _recorded_survivor_regions(0),
147 _recorded_survivor_head(NULL),
148 _recorded_survivor_tail(NULL),
149 _survivors_age_table(true),
150
151 _gc_overhead_perc(0.0) {
152
153 // SurvRateGroups below must be initialized after the predictor because they
154 // indirectly use it through this object passed to their constructor.
155 _short_lived_surv_rate_group =
156 new SurvRateGroup(&_predictor, "Short Lived", G1YoungSurvRateNumRegionsSummary);
157 _survivor_surv_rate_group =
158 new SurvRateGroup(&_predictor, "Survivor", G1YoungSurvRateNumRegionsSummary);
159
160 // Set up the region size and associated fields. Given that the
161 // policy is created before the heap, we have to set this up here,
162 // so it's done as soon as possible.
163
164 // It would have been natural to pass initial_heap_byte_size() and
165 // max_heap_byte_size() to setup_heap_region_size() but those have
166 // not been set up at this point since they should be aligned with
167 // the region size. So, there is a circular dependency here. We base
168 // the region size on the heap size, but the heap size should be
169 // aligned with the region size. To get around this we use the
170 // unaligned values for the heap.
171 HeapRegion::setup_heap_region_size(InitialHeapSize, MaxHeapSize);
172 HeapRegionRemSet::setup_remset_size();
173
174 _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime());
175 _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0;
176
177 _phase_times = new G1GCPhaseTimes(_parallel_gc_threads);
178
179 int index = MIN2(_parallel_gc_threads - 1, 7);
180
181 _rs_length_diff_seq->add(rs_length_diff_defaults[index]);
182 _cost_per_card_ms_seq->add(cost_per_card_ms_defaults[index]);
183 _cost_scan_hcc_seq->add(0.0);
184 _young_cards_per_entry_ratio_seq->add(
185 young_cards_per_entry_ratio_defaults[index]);
186 _cost_per_entry_ms_seq->add(cost_per_entry_ms_defaults[index]);
187 _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]);
188 _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]);
189 _young_other_cost_per_region_ms_seq->add(
190 young_other_cost_per_region_ms_defaults[index]);
191 _non_young_other_cost_per_region_ms_seq->add(
192 non_young_other_cost_per_region_ms_defaults[index]);
193
194 // Below, we might need to calculate the pause time target based on
195 // the pause interval. When we do so we are going to give G1 maximum
196 // flexibility and allow it to do pauses when it needs to. So, we'll
197 // arrange that the pause interval to be pause time target + 1 to
198 // ensure that a) the pause time target is maximized with respect to
199 // the pause interval and b) we maintain the invariant that pause
200 // time target < pause interval. If the user does not want this
201 // maximum flexibility, they will have to set the pause interval
202 // explicitly.
203
204 // First make sure that, if either parameter is set, its value is
205 // reasonable.
206 if (!FLAG_IS_DEFAULT(MaxGCPauseMillis)) {
207 if (MaxGCPauseMillis < 1) {
208 vm_exit_during_initialization("MaxGCPauseMillis should be "
209 "greater than 0");
210 }
211 }
212 if (!FLAG_IS_DEFAULT(GCPauseIntervalMillis)) {
213 if (GCPauseIntervalMillis < 1) {
214 vm_exit_during_initialization("GCPauseIntervalMillis should be "
215 "greater than 0");
216 }
217 }
218
219 // Then, if the pause time target parameter was not set, set it to
220 // the default value.
221 if (FLAG_IS_DEFAULT(MaxGCPauseMillis)) {
222 if (FLAG_IS_DEFAULT(GCPauseIntervalMillis)) {
223 // The default pause time target in G1 is 200ms
224 FLAG_SET_DEFAULT(MaxGCPauseMillis, 200);
225 } else {
226 // We do not allow the pause interval to be set without the
227 // pause time target
228 vm_exit_during_initialization("GCPauseIntervalMillis cannot be set "
229 "without setting MaxGCPauseMillis");
230 }
231 }
232
233 // Then, if the interval parameter was not set, set it according to
234 // the pause time target (this will also deal with the case when the
235 // pause time target is the default value).
236 if (FLAG_IS_DEFAULT(GCPauseIntervalMillis)) {
237 FLAG_SET_DEFAULT(GCPauseIntervalMillis, MaxGCPauseMillis + 1);
238 }
239
240 // Finally, make sure that the two parameters are consistent.
241 if (MaxGCPauseMillis >= GCPauseIntervalMillis) {
242 char buffer[256];
243 jio_snprintf(buffer, 256,
244 "MaxGCPauseMillis (%u) should be less than "
245 "GCPauseIntervalMillis (%u)",
246 MaxGCPauseMillis, GCPauseIntervalMillis);
247 vm_exit_during_initialization(buffer);
248 }
249
250 double max_gc_time = (double) MaxGCPauseMillis / 1000.0;
251 double time_slice = (double) GCPauseIntervalMillis / 1000.0;
252 _mmu_tracker = new G1MMUTrackerQueue(time_slice, max_gc_time);
253
254 // start conservatively (around 50ms is about right)
255 _concurrent_mark_remark_times_ms->add(0.05);
256 _concurrent_mark_cleanup_times_ms->add(0.20);
257 _tenuring_threshold = MaxTenuringThreshold;
258
259 assert(GCTimeRatio > 0,
260 "we should have set it to a default value set_g1_gc_flags() "
261 "if a user set it to 0");
262 _gc_overhead_perc = 100.0 * (1.0 / (1.0 + GCTimeRatio));
263
264 uintx reserve_perc = G1ReservePercent;
265 // Put an artificial ceiling on this so that it's not set to a silly value.
266 if (reserve_perc > 50) {
267 reserve_perc = 50;
268 warning("G1ReservePercent is set to a value that is too large, "
269 "it's been updated to " UINTX_FORMAT, reserve_perc);
270 }
271 _reserve_factor = (double) reserve_perc / 100.0;
272 // This will be set when the heap is expanded
273 // for the first time during initialization.
274 _reserve_regions = 0;
275
276 _collectionSetChooser = new CollectionSetChooser();
277 }
278
279 double G1CollectorPolicy::get_new_prediction(TruncatedSeq const* seq) const {
280 return _predictor.get_new_prediction(seq);
281 }
282
283 void G1CollectorPolicy::initialize_alignments() {
284 _space_alignment = HeapRegion::GrainBytes;
285 size_t card_table_alignment = CardTableRS::ct_max_alignment_constraint();
286 size_t page_size = UseLargePages ? os::large_page_size() : os::vm_page_size();
287 _heap_alignment = MAX3(card_table_alignment, _space_alignment, page_size);
288 }
289
290 void G1CollectorPolicy::initialize_flags() {
291 if (G1HeapRegionSize != HeapRegion::GrainBytes) {
292 FLAG_SET_ERGO(size_t, G1HeapRegionSize, HeapRegion::GrainBytes);
293 }
294
295 if (SurvivorRatio < 1) {
296 vm_exit_during_initialization("Invalid survivor ratio specified");
297 }
298 CollectorPolicy::initialize_flags();
299 _young_gen_sizer = new G1YoungGenSizer(); // Must be after call to initialize_flags
300 }
301
302 void G1CollectorPolicy::post_heap_initialize() {
303 uintx max_regions = G1CollectedHeap::heap()->max_regions();
304 size_t max_young_size = (size_t)_young_gen_sizer->max_young_length(max_regions) * HeapRegion::GrainBytes;
305 if (max_young_size != MaxNewSize) {
306 FLAG_SET_ERGO(size_t, MaxNewSize, max_young_size);
307 }
308 }
309
310 G1CollectorState* G1CollectorPolicy::collector_state() const { return _g1->collector_state(); }
311
312 G1YoungGenSizer::G1YoungGenSizer() : _sizer_kind(SizerDefaults), _adaptive_size(true),
313 _min_desired_young_length(0), _max_desired_young_length(0) {
314 if (FLAG_IS_CMDLINE(NewRatio)) {
315 if (FLAG_IS_CMDLINE(NewSize) || FLAG_IS_CMDLINE(MaxNewSize)) {
316 warning("-XX:NewSize and -XX:MaxNewSize override -XX:NewRatio");
317 } else {
318 _sizer_kind = SizerNewRatio;
319 _adaptive_size = false;
320 return;
321 }
322 }
323
324 if (NewSize > MaxNewSize) {
325 if (FLAG_IS_CMDLINE(MaxNewSize)) {
326 warning("NewSize (" SIZE_FORMAT "k) is greater than the MaxNewSize (" SIZE_FORMAT "k). "
327 "A new max generation size of " SIZE_FORMAT "k will be used.",
328 NewSize/K, MaxNewSize/K, NewSize/K);
329 }
330 MaxNewSize = NewSize;
331 }
332
333 if (FLAG_IS_CMDLINE(NewSize)) {
334 _min_desired_young_length = MAX2((uint) (NewSize / HeapRegion::GrainBytes),
335 1U);
336 if (FLAG_IS_CMDLINE(MaxNewSize)) {
337 _max_desired_young_length =
338 MAX2((uint) (MaxNewSize / HeapRegion::GrainBytes),
339 1U);
340 _sizer_kind = SizerMaxAndNewSize;
341 _adaptive_size = _min_desired_young_length == _max_desired_young_length;
342 } else {
343 _sizer_kind = SizerNewSizeOnly;
344 }
345 } else if (FLAG_IS_CMDLINE(MaxNewSize)) {
346 _max_desired_young_length =
347 MAX2((uint) (MaxNewSize / HeapRegion::GrainBytes),
348 1U);
349 _sizer_kind = SizerMaxNewSizeOnly;
350 }
351 }
352
353 uint G1YoungGenSizer::calculate_default_min_length(uint new_number_of_heap_regions) {
354 uint default_value = (new_number_of_heap_regions * G1NewSizePercent) / 100;
355 return MAX2(1U, default_value);
356 }
357
358 uint G1YoungGenSizer::calculate_default_max_length(uint new_number_of_heap_regions) {
359 uint default_value = (new_number_of_heap_regions * G1MaxNewSizePercent) / 100;
360 return MAX2(1U, default_value);
361 }
362
363 void G1YoungGenSizer::recalculate_min_max_young_length(uint number_of_heap_regions, uint* min_young_length, uint* max_young_length) {
364 assert(number_of_heap_regions > 0, "Heap must be initialized");
365
366 switch (_sizer_kind) {
367 case SizerDefaults:
368 *min_young_length = calculate_default_min_length(number_of_heap_regions);
369 *max_young_length = calculate_default_max_length(number_of_heap_regions);
370 break;
371 case SizerNewSizeOnly:
372 *max_young_length = calculate_default_max_length(number_of_heap_regions);
373 *max_young_length = MAX2(*min_young_length, *max_young_length);
374 break;
375 case SizerMaxNewSizeOnly:
376 *min_young_length = calculate_default_min_length(number_of_heap_regions);
377 *min_young_length = MIN2(*min_young_length, *max_young_length);
378 break;
379 case SizerMaxAndNewSize:
380 // Do nothing. Values set on the command line, don't update them at runtime.
381 break;
382 case SizerNewRatio:
383 *min_young_length = number_of_heap_regions / (NewRatio + 1);
384 *max_young_length = *min_young_length;
385 break;
386 default:
387 ShouldNotReachHere();
388 }
389
390 assert(*min_young_length <= *max_young_length, "Invalid min/max young gen size values");
391 }
392
393 uint G1YoungGenSizer::max_young_length(uint number_of_heap_regions) {
394 // We need to pass the desired values because recalculation may not update these
395 // values in some cases.
396 uint temp = _min_desired_young_length;
397 uint result = _max_desired_young_length;
398 recalculate_min_max_young_length(number_of_heap_regions, &temp, &result);
399 return result;
400 }
401
402 void G1YoungGenSizer::heap_size_changed(uint new_number_of_heap_regions) {
403 recalculate_min_max_young_length(new_number_of_heap_regions, &_min_desired_young_length,
404 &_max_desired_young_length);
405 }
406
407 void G1CollectorPolicy::init() {
408 // Set aside an initial future to_space.
409 _g1 = G1CollectedHeap::heap();
410
411 assert(Heap_lock->owned_by_self(), "Locking discipline.");
412
413 initialize_gc_policy_counters();
414
415 if (adaptive_young_list_length()) {
416 _young_list_fixed_length = 0;
417 } else {
418 _young_list_fixed_length = _young_gen_sizer->min_desired_young_length();
419 }
420 _free_regions_at_end_of_collection = _g1->num_free_regions();
421
422 update_young_list_max_and_target_length();
423 // We may immediately start allocating regions and placing them on the
424 // collection set list. Initialize the per-collection set info
425 start_incremental_cset_building();
426 }
427
428 void G1CollectorPolicy::note_gc_start(uint num_active_workers) {
429 phase_times()->note_gc_start(num_active_workers);
430 }
431
432 // Create the jstat counters for the policy.
433 void G1CollectorPolicy::initialize_gc_policy_counters() {
434 _gc_policy_counters = new GCPolicyCounters("GarbageFirst", 1, 3);
435 }
436
437 bool G1CollectorPolicy::predict_will_fit(uint young_length,
438 double base_time_ms,
439 uint base_free_regions,
440 double target_pause_time_ms) const {
441 if (young_length >= base_free_regions) {
442 // end condition 1: not enough space for the young regions
443 return false;
444 }
445
446 double accum_surv_rate = accum_yg_surv_rate_pred((int) young_length - 1);
447 size_t bytes_to_copy =
448 (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
449 double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
450 double young_other_time_ms = predict_young_other_time_ms(young_length);
451 double pause_time_ms = base_time_ms + copy_time_ms + young_other_time_ms;
452 if (pause_time_ms > target_pause_time_ms) {
453 // end condition 2: prediction is over the target pause time
454 return false;
455 }
456
457 size_t free_bytes = (base_free_regions - young_length) * HeapRegion::GrainBytes;
458 if ((2.0 /* magic */ * _predictor.sigma()) * bytes_to_copy > free_bytes) {
459 // end condition 3: out-of-space (conservatively!)
460 return false;
461 }
462
463 // success!
464 return true;
465 }
466
467 void G1CollectorPolicy::record_new_heap_size(uint new_number_of_regions) {
468 // re-calculate the necessary reserve
469 double reserve_regions_d = (double) new_number_of_regions * _reserve_factor;
470 // We use ceiling so that if reserve_regions_d is > 0.0 (but
471 // smaller than 1.0) we'll get 1.
472 _reserve_regions = (uint) ceil(reserve_regions_d);
473
474 _young_gen_sizer->heap_size_changed(new_number_of_regions);
475 }
476
477 uint G1CollectorPolicy::calculate_young_list_desired_min_length(
478 uint base_min_length) const {
479 uint desired_min_length = 0;
480 if (adaptive_young_list_length()) {
481 if (_alloc_rate_ms_seq->num() > 3) {
482 double now_sec = os::elapsedTime();
483 double when_ms = _mmu_tracker->when_max_gc_sec(now_sec) * 1000.0;
484 double alloc_rate_ms = predict_alloc_rate_ms();
485 desired_min_length = (uint) ceil(alloc_rate_ms * when_ms);
486 } else {
487 // otherwise we don't have enough info to make the prediction
488 }
489 }
490 desired_min_length += base_min_length;
491 // make sure we don't go below any user-defined minimum bound
492 return MAX2(_young_gen_sizer->min_desired_young_length(), desired_min_length);
493 }
494
495 uint G1CollectorPolicy::calculate_young_list_desired_max_length() const {
496 // Here, we might want to also take into account any additional
497 // constraints (i.e., user-defined minimum bound). Currently, we
498 // effectively don't set this bound.
499 return _young_gen_sizer->max_desired_young_length();
500 }
501
502 void G1CollectorPolicy::update_young_list_max_and_target_length() {
503 update_young_list_max_and_target_length(get_new_prediction(_rs_lengths_seq));
504 }
505
506 void G1CollectorPolicy::update_young_list_max_and_target_length(size_t rs_lengths) {
507 update_young_list_target_length(rs_lengths);
508 update_max_gc_locker_expansion();
509 }
510
511 void G1CollectorPolicy::update_young_list_target_length(size_t rs_lengths) {
512 _young_list_target_length = bounded_young_list_target_length(rs_lengths);
513 }
514
515 void G1CollectorPolicy::update_young_list_target_length() {
516 update_young_list_target_length(get_new_prediction(_rs_lengths_seq));
517 }
518
519 uint G1CollectorPolicy::bounded_young_list_target_length(size_t rs_lengths) const {
520 // Calculate the absolute and desired min bounds.
521
522 // This is how many young regions we already have (currently: the survivors).
523 uint base_min_length = recorded_survivor_regions();
524 uint desired_min_length = calculate_young_list_desired_min_length(base_min_length);
525 // This is the absolute minimum young length. Ensure that we
526 // will at least have one eden region available for allocation.
527 uint absolute_min_length = base_min_length + MAX2(_g1->young_list()->eden_length(), (uint)1);
528 // If we shrank the young list target it should not shrink below the current size.
529 desired_min_length = MAX2(desired_min_length, absolute_min_length);
530 // Calculate the absolute and desired max bounds.
531
532 // We will try our best not to "eat" into the reserve.
533 uint absolute_max_length = 0;
534 if (_free_regions_at_end_of_collection > _reserve_regions) {
535 absolute_max_length = _free_regions_at_end_of_collection - _reserve_regions;
536 }
537 uint desired_max_length = calculate_young_list_desired_max_length();
538 if (desired_max_length > absolute_max_length) {
539 desired_max_length = absolute_max_length;
540 }
541
542 uint young_list_target_length = 0;
543 if (adaptive_young_list_length()) {
544 if (collector_state()->gcs_are_young()) {
545 young_list_target_length =
546 calculate_young_list_target_length(rs_lengths,
547 base_min_length,
548 desired_min_length,
549 desired_max_length);
550 } else {
551 // Don't calculate anything and let the code below bound it to
552 // the desired_min_length, i.e., do the next GC as soon as
553 // possible to maximize how many old regions we can add to it.
554 }
555 } else {
556 // The user asked for a fixed young gen so we'll fix the young gen
557 // whether the next GC is young or mixed.
558 young_list_target_length = _young_list_fixed_length;
559 }
560
561 // Make sure we don't go over the desired max length, nor under the
562 // desired min length. In case they clash, desired_min_length wins
563 // which is why that test is second.
564 if (young_list_target_length > desired_max_length) {
565 young_list_target_length = desired_max_length;
566 }
567 if (young_list_target_length < desired_min_length) {
568 young_list_target_length = desired_min_length;
569 }
570
571 assert(young_list_target_length > recorded_survivor_regions(),
572 "we should be able to allocate at least one eden region");
573 assert(young_list_target_length >= absolute_min_length, "post-condition");
574
575 return young_list_target_length;
576 }
577
578 uint
579 G1CollectorPolicy::calculate_young_list_target_length(size_t rs_lengths,
580 uint base_min_length,
581 uint desired_min_length,
582 uint desired_max_length) const {
583 assert(adaptive_young_list_length(), "pre-condition");
584 assert(collector_state()->gcs_are_young(), "only call this for young GCs");
585
586 // In case some edge-condition makes the desired max length too small...
587 if (desired_max_length <= desired_min_length) {
588 return desired_min_length;
589 }
590
591 // We'll adjust min_young_length and max_young_length not to include
592 // the already allocated young regions (i.e., so they reflect the
593 // min and max eden regions we'll allocate). The base_min_length
594 // will be reflected in the predictions by the
595 // survivor_regions_evac_time prediction.
596 assert(desired_min_length > base_min_length, "invariant");
597 uint min_young_length = desired_min_length - base_min_length;
598 assert(desired_max_length > base_min_length, "invariant");
599 uint max_young_length = desired_max_length - base_min_length;
600
601 double target_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
602 double survivor_regions_evac_time = predict_survivor_regions_evac_time();
603 size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
604 size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
605 size_t scanned_cards = predict_young_card_num(adj_rs_lengths);
606 double base_time_ms =
607 predict_base_elapsed_time_ms(pending_cards, scanned_cards) +
608 survivor_regions_evac_time;
609 uint available_free_regions = _free_regions_at_end_of_collection;
610 uint base_free_regions = 0;
611 if (available_free_regions > _reserve_regions) {
612 base_free_regions = available_free_regions - _reserve_regions;
613 }
614
615 // Here, we will make sure that the shortest young length that
616 // makes sense fits within the target pause time.
617
618 if (predict_will_fit(min_young_length, base_time_ms,
619 base_free_regions, target_pause_time_ms)) {
620 // The shortest young length will fit into the target pause time;
621 // we'll now check whether the absolute maximum number of young
622 // regions will fit in the target pause time. If not, we'll do
623 // a binary search between min_young_length and max_young_length.
624 if (predict_will_fit(max_young_length, base_time_ms,
625 base_free_regions, target_pause_time_ms)) {
626 // The maximum young length will fit into the target pause time.
627 // We are done so set min young length to the maximum length (as
628 // the result is assumed to be returned in min_young_length).
629 min_young_length = max_young_length;
630 } else {
631 // The maximum possible number of young regions will not fit within
632 // the target pause time so we'll search for the optimal
633 // length. The loop invariants are:
634 //
635 // min_young_length < max_young_length
636 // min_young_length is known to fit into the target pause time
637 // max_young_length is known not to fit into the target pause time
638 //
639 // Going into the loop we know the above hold as we've just
640 // checked them. Every time around the loop we check whether
641 // the middle value between min_young_length and
642 // max_young_length fits into the target pause time. If it
643 // does, it becomes the new min. If it doesn't, it becomes
644 // the new max. This way we maintain the loop invariants.
645
646 assert(min_young_length < max_young_length, "invariant");
647 uint diff = (max_young_length - min_young_length) / 2;
648 while (diff > 0) {
649 uint young_length = min_young_length + diff;
650 if (predict_will_fit(young_length, base_time_ms,
651 base_free_regions, target_pause_time_ms)) {
652 min_young_length = young_length;
653 } else {
654 max_young_length = young_length;
655 }
656 assert(min_young_length < max_young_length, "invariant");
657 diff = (max_young_length - min_young_length) / 2;
658 }
659 // The results is min_young_length which, according to the
660 // loop invariants, should fit within the target pause time.
661
662 // These are the post-conditions of the binary search above:
663 assert(min_young_length < max_young_length,
664 "otherwise we should have discovered that max_young_length "
665 "fits into the pause target and not done the binary search");
666 assert(predict_will_fit(min_young_length, base_time_ms,
667 base_free_regions, target_pause_time_ms),
668 "min_young_length, the result of the binary search, should "
669 "fit into the pause target");
670 assert(!predict_will_fit(min_young_length + 1, base_time_ms,
671 base_free_regions, target_pause_time_ms),
672 "min_young_length, the result of the binary search, should be "
673 "optimal, so no larger length should fit into the pause target");
674 }
675 } else {
676 // Even the minimum length doesn't fit into the pause time
677 // target, return it as the result nevertheless.
678 }
679 return base_min_length + min_young_length;
680 }
681
682 double G1CollectorPolicy::predict_survivor_regions_evac_time() const {
683 double survivor_regions_evac_time = 0.0;
684 for (HeapRegion * r = _recorded_survivor_head;
685 r != NULL && r != _recorded_survivor_tail->get_next_young_region();
686 r = r->get_next_young_region()) {
687 survivor_regions_evac_time += predict_region_elapsed_time_ms(r, collector_state()->gcs_are_young());
688 }
689 return survivor_regions_evac_time;
690 }
691
692 void G1CollectorPolicy::revise_young_list_target_length_if_necessary() {
693 guarantee( adaptive_young_list_length(), "should not call this otherwise" );
694
695 size_t rs_lengths = _g1->young_list()->sampled_rs_lengths();
696 if (rs_lengths > _rs_lengths_prediction) {
697 // add 10% to avoid having to recalculate often
698 size_t rs_lengths_prediction = rs_lengths * 1100 / 1000;
699 update_rs_lengths_prediction(rs_lengths_prediction);
700
701 update_young_list_max_and_target_length(rs_lengths_prediction);
702 }
703 }
704
705 void G1CollectorPolicy::update_rs_lengths_prediction() {
706 update_rs_lengths_prediction(get_new_prediction(_rs_lengths_seq));
707 }
708
709 void G1CollectorPolicy::update_rs_lengths_prediction(size_t prediction) {
710 if (collector_state()->gcs_are_young() && adaptive_young_list_length()) {
711 _rs_lengths_prediction = prediction;
712 }
713 }
714
715 HeapWord* G1CollectorPolicy::mem_allocate_work(size_t size,
716 bool is_tlab,
717 bool* gc_overhead_limit_was_exceeded) {
718 guarantee(false, "Not using this policy feature yet.");
719 return NULL;
720 }
721
722 // This method controls how a collector handles one or more
723 // of its generations being fully allocated.
724 HeapWord* G1CollectorPolicy::satisfy_failed_allocation(size_t size,
725 bool is_tlab) {
726 guarantee(false, "Not using this policy feature yet.");
727 return NULL;
728 }
729
730
731 #ifndef PRODUCT
732 bool G1CollectorPolicy::verify_young_ages() {
733 HeapRegion* head = _g1->young_list()->first_region();
734 return
735 verify_young_ages(head, _short_lived_surv_rate_group);
736 // also call verify_young_ages on any additional surv rate groups
737 }
738
739 bool
740 G1CollectorPolicy::verify_young_ages(HeapRegion* head,
741 SurvRateGroup *surv_rate_group) {
742 guarantee( surv_rate_group != NULL, "pre-condition" );
743
744 const char* name = surv_rate_group->name();
745 bool ret = true;
746 int prev_age = -1;
747
748 for (HeapRegion* curr = head;
749 curr != NULL;
750 curr = curr->get_next_young_region()) {
751 SurvRateGroup* group = curr->surv_rate_group();
752 if (group == NULL && !curr->is_survivor()) {
753 log_info(gc, verify)("## %s: encountered NULL surv_rate_group", name);
754 ret = false;
755 }
756
757 if (surv_rate_group == group) {
758 int age = curr->age_in_surv_rate_group();
759
760 if (age < 0) {
761 log_info(gc, verify)("## %s: encountered negative age", name);
762 ret = false;
763 }
764
765 if (age <= prev_age) {
766 log_info(gc, verify)("## %s: region ages are not strictly increasing (%d, %d)", name, age, prev_age);
767 ret = false;
768 }
769 prev_age = age;
770 }
771 }
772
773 return ret;
774 }
775 #endif // PRODUCT
776
777 void G1CollectorPolicy::record_full_collection_start() {
778 _full_collection_start_sec = os::elapsedTime();
779 record_heap_size_info_at_start(true /* full */);
780 // Release the future to-space so that it is available for compaction into.
781 collector_state()->set_full_collection(true);
782 }
783
784 void G1CollectorPolicy::record_full_collection_end() {
785 // Consider this like a collection pause for the purposes of allocation
786 // since last pause.
787 double end_sec = os::elapsedTime();
788 double full_gc_time_sec = end_sec - _full_collection_start_sec;
789 double full_gc_time_ms = full_gc_time_sec * 1000.0;
790
791 _trace_old_gen_time_data.record_full_collection(full_gc_time_ms);
792
793 update_recent_gc_times(end_sec, full_gc_time_ms);
794
795 collector_state()->set_full_collection(false);
796
797 // "Nuke" the heuristics that control the young/mixed GC
798 // transitions and make sure we start with young GCs after the Full GC.
799 collector_state()->set_gcs_are_young(true);
800 collector_state()->set_last_young_gc(false);
801 collector_state()->set_initiate_conc_mark_if_possible(false);
802 collector_state()->set_during_initial_mark_pause(false);
803 collector_state()->set_in_marking_window(false);
804 collector_state()->set_in_marking_window_im(false);
805
806 _short_lived_surv_rate_group->start_adding_regions();
807 // also call this on any additional surv rate groups
808
809 record_survivor_regions(0, NULL, NULL);
810
811 _free_regions_at_end_of_collection = _g1->num_free_regions();
812 // Reset survivors SurvRateGroup.
813 _survivor_surv_rate_group->reset();
814 update_young_list_max_and_target_length();
815 update_rs_lengths_prediction();
816 _collectionSetChooser->clear();
817 }
818
819 void G1CollectorPolicy::record_stop_world_start() {
820 _stop_world_start = os::elapsedTime();
821 }
822
823 void G1CollectorPolicy::record_collection_pause_start(double start_time_sec) {
824 // We only need to do this here as the policy will only be applied
825 // to the GC we're about to start. so, no point is calculating this
826 // every time we calculate / recalculate the target young length.
827 update_survivors_policy();
828
829 assert(_g1->used() == _g1->recalculate_used(),
830 "sanity, used: " SIZE_FORMAT " recalculate_used: " SIZE_FORMAT,
831 _g1->used(), _g1->recalculate_used());
832
833 double s_w_t_ms = (start_time_sec - _stop_world_start) * 1000.0;
834 _trace_young_gen_time_data.record_start_collection(s_w_t_ms);
835 _stop_world_start = 0.0;
836
837 record_heap_size_info_at_start(false /* full */);
838
839 phase_times()->record_cur_collection_start_sec(start_time_sec);
840 _pending_cards = _g1->pending_card_num();
841
842 _collection_set_bytes_used_before = 0;
843 _bytes_copied_during_gc = 0;
844
845 collector_state()->set_last_gc_was_young(false);
846
847 // do that for any other surv rate groups
848 _short_lived_surv_rate_group->stop_adding_regions();
849 _survivors_age_table.clear();
850
851 assert( verify_young_ages(), "region age verification" );
852 }
853
854 void G1CollectorPolicy::record_concurrent_mark_init_end(double
855 mark_init_elapsed_time_ms) {
856 collector_state()->set_during_marking(true);
857 assert(!collector_state()->initiate_conc_mark_if_possible(), "we should have cleared it by now");
858 collector_state()->set_during_initial_mark_pause(false);
859 _cur_mark_stop_world_time_ms = mark_init_elapsed_time_ms;
860 }
861
862 void G1CollectorPolicy::record_concurrent_mark_remark_start() {
863 _mark_remark_start_sec = os::elapsedTime();
864 collector_state()->set_during_marking(false);
865 }
866
867 void G1CollectorPolicy::record_concurrent_mark_remark_end() {
868 double end_time_sec = os::elapsedTime();
869 double elapsed_time_ms = (end_time_sec - _mark_remark_start_sec)*1000.0;
870 _concurrent_mark_remark_times_ms->add(elapsed_time_ms);
871 _cur_mark_stop_world_time_ms += elapsed_time_ms;
872 _prev_collection_pause_end_ms += elapsed_time_ms;
873
874 _mmu_tracker->add_pause(_mark_remark_start_sec, end_time_sec);
875 }
876
877 void G1CollectorPolicy::record_concurrent_mark_cleanup_start() {
878 _mark_cleanup_start_sec = os::elapsedTime();
879 }
880
881 void G1CollectorPolicy::record_concurrent_mark_cleanup_completed() {
882 collector_state()->set_last_young_gc(true);
883 collector_state()->set_in_marking_window(false);
884 }
885
886 void G1CollectorPolicy::record_concurrent_pause() {
887 if (_stop_world_start > 0.0) {
888 double yield_ms = (os::elapsedTime() - _stop_world_start) * 1000.0;
889 _trace_young_gen_time_data.record_yield_time(yield_ms);
890 }
891 }
892
893 double G1CollectorPolicy::average_time_ms(G1GCPhaseTimes::GCParPhases phase) const {
894 return phase_times()->average_time_ms(phase);
895 }
896
897 bool G1CollectorPolicy::need_to_start_conc_mark(const char* source, size_t alloc_word_size) {
898 if (_g1->concurrent_mark()->cmThread()->during_cycle()) {
899 return false;
900 }
901
902 size_t marking_initiating_used_threshold =
903 (_g1->capacity() / 100) * InitiatingHeapOccupancyPercent;
904 size_t cur_used_bytes = _g1->non_young_capacity_bytes();
905 size_t alloc_byte_size = alloc_word_size * HeapWordSize;
906
907 if ((cur_used_bytes + alloc_byte_size) > marking_initiating_used_threshold) {
908 if (collector_state()->gcs_are_young() && !collector_state()->last_young_gc()) {
909 log_debug(gc, ergo, conc)("Request concurrent cycle initiation (occupancy higher than threshold)"
910 "occupancy: " SIZE_FORMAT "B allocation request: " SIZE_FORMAT "B threshold: " SIZE_FORMAT "B (" UINTX_FORMAT "%%) source: %s",
911 cur_used_bytes, alloc_byte_size, marking_initiating_used_threshold, InitiatingHeapOccupancyPercent, source);
912 return true;
913 } else {
914 log_debug(gc, ergo, conc)("Do not request concurrent cycle initiation (still doing mixed collections)"
915 "occupancy: " SIZE_FORMAT "B allocation request: " SIZE_FORMAT "B threshold: " SIZE_FORMAT "B (" UINTX_FORMAT "%%) source: %s",
916 cur_used_bytes, alloc_byte_size, marking_initiating_used_threshold, InitiatingHeapOccupancyPercent, source); }
917 }
918
919 return false;
920 }
921
922 // Anything below that is considered to be zero
923 #define MIN_TIMER_GRANULARITY 0.0000001
924
925 void G1CollectorPolicy::record_collection_pause_end(double pause_time_ms, size_t cards_scanned) {
926 double end_time_sec = os::elapsedTime();
927 assert(_cur_collection_pause_used_regions_at_start >= cset_region_length(),
928 "otherwise, the subtraction below does not make sense");
929 size_t rs_size =
930 _cur_collection_pause_used_regions_at_start - cset_region_length();
931 size_t cur_used_bytes = _g1->used();
932 assert(cur_used_bytes == _g1->recalculate_used(), "It should!");
933 bool last_pause_included_initial_mark = false;
934 bool update_stats = !_g1->evacuation_failed();
935
936 NOT_PRODUCT(_short_lived_surv_rate_group->print());
937
938 last_pause_included_initial_mark = collector_state()->during_initial_mark_pause();
939 if (last_pause_included_initial_mark) {
940 record_concurrent_mark_init_end(0.0);
941 } else if (need_to_start_conc_mark("end of GC")) {
942 // Note: this might have already been set, if during the last
943 // pause we decided to start a cycle but at the beginning of
944 // this pause we decided to postpone it. That's OK.
945 collector_state()->set_initiate_conc_mark_if_possible(true);
946 }
947
948 _mmu_tracker->add_pause(end_time_sec - pause_time_ms/1000.0, end_time_sec);
949
950 if (update_stats) {
951 _trace_young_gen_time_data.record_end_collection(pause_time_ms, phase_times());
952 // this is where we update the allocation rate of the application
953 double app_time_ms =
954 (phase_times()->cur_collection_start_sec() * 1000.0 - _prev_collection_pause_end_ms);
955 if (app_time_ms < MIN_TIMER_GRANULARITY) {
956 // This usually happens due to the timer not having the required
957 // granularity. Some Linuxes are the usual culprits.
958 // We'll just set it to something (arbitrarily) small.
959 app_time_ms = 1.0;
960 }
961 // We maintain the invariant that all objects allocated by mutator
962 // threads will be allocated out of eden regions. So, we can use
963 // the eden region number allocated since the previous GC to
964 // calculate the application's allocate rate. The only exception
965 // to that is humongous objects that are allocated separately. But
966 // given that humongous object allocations do not really affect
967 // either the pause's duration nor when the next pause will take
968 // place we can safely ignore them here.
969 uint regions_allocated = eden_cset_region_length();
970 double alloc_rate_ms = (double) regions_allocated / app_time_ms;
971 _alloc_rate_ms_seq->add(alloc_rate_ms);
972
973 double interval_ms =
974 (end_time_sec - _recent_prev_end_times_for_all_gcs_sec->oldest()) * 1000.0;
975 update_recent_gc_times(end_time_sec, pause_time_ms);
976 _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum()/interval_ms;
977 if (recent_avg_pause_time_ratio() < 0.0 ||
978 (recent_avg_pause_time_ratio() - 1.0 > 0.0)) {
979 #ifndef PRODUCT
980 // Dump info to allow post-facto debugging
981 gclog_or_tty->print_cr("recent_avg_pause_time_ratio() out of bounds");
982 gclog_or_tty->print_cr("-------------------------------------------");
983 gclog_or_tty->print_cr("Recent GC Times (ms):");
984 _recent_gc_times_ms->dump();
985 gclog_or_tty->print_cr("(End Time=%3.3f) Recent GC End Times (s):", end_time_sec);
986 _recent_prev_end_times_for_all_gcs_sec->dump();
987 gclog_or_tty->print_cr("GC = %3.3f, Interval = %3.3f, Ratio = %3.3f",
988 _recent_gc_times_ms->sum(), interval_ms, recent_avg_pause_time_ratio());
989 // In debug mode, terminate the JVM if the user wants to debug at this point.
990 assert(!G1FailOnFPError, "Debugging data for CR 6898948 has been dumped above");
991 #endif // !PRODUCT
992 // Clip ratio between 0.0 and 1.0, and continue. This will be fixed in
993 // CR 6902692 by redoing the manner in which the ratio is incrementally computed.
994 if (_recent_avg_pause_time_ratio < 0.0) {
995 _recent_avg_pause_time_ratio = 0.0;
996 } else {
997 assert(_recent_avg_pause_time_ratio - 1.0 > 0.0, "Ctl-point invariant");
998 _recent_avg_pause_time_ratio = 1.0;
999 }
1000 }
1001 }
1002
1003 bool new_in_marking_window = collector_state()->in_marking_window();
1004 bool new_in_marking_window_im = false;
1005 if (last_pause_included_initial_mark) {
1006 new_in_marking_window = true;
1007 new_in_marking_window_im = true;
1008 }
1009
1010 if (collector_state()->last_young_gc()) {
1011 // This is supposed to to be the "last young GC" before we start
1012 // doing mixed GCs. Here we decide whether to start mixed GCs or not.
1013
1014 if (!last_pause_included_initial_mark) {
1015 if (next_gc_should_be_mixed("start mixed GCs",
1016 "do not start mixed GCs")) {
1017 collector_state()->set_gcs_are_young(false);
1018 }
1019 } else {
1020 log_debug(gc, ergo)("Do not start mixed GCs (concurrent cycle is about to start)");
1021 }
1022 collector_state()->set_last_young_gc(false);
1023 }
1024
1025 if (!collector_state()->last_gc_was_young()) {
1026 // This is a mixed GC. Here we decide whether to continue doing
1027 // mixed GCs or not.
1028
1029 if (!next_gc_should_be_mixed("continue mixed GCs",
1030 "do not continue mixed GCs")) {
1031 collector_state()->set_gcs_are_young(true);
1032 }
1033 }
1034
1035 _short_lived_surv_rate_group->start_adding_regions();
1036 // Do that for any other surv rate groups
1037
1038 if (update_stats) {
1039 double cost_per_card_ms = 0.0;
1040 double cost_scan_hcc = average_time_ms(G1GCPhaseTimes::ScanHCC);
1041 if (_pending_cards > 0) {
1042 cost_per_card_ms = (average_time_ms(G1GCPhaseTimes::UpdateRS) - cost_scan_hcc) / (double) _pending_cards;
1043 _cost_per_card_ms_seq->add(cost_per_card_ms);
1044 }
1045 _cost_scan_hcc_seq->add(cost_scan_hcc);
1046
1047 double cost_per_entry_ms = 0.0;
1048 if (cards_scanned > 10) {
1049 cost_per_entry_ms = average_time_ms(G1GCPhaseTimes::ScanRS) / (double) cards_scanned;
1050 if (collector_state()->last_gc_was_young()) {
1051 _cost_per_entry_ms_seq->add(cost_per_entry_ms);
1052 } else {
1053 _mixed_cost_per_entry_ms_seq->add(cost_per_entry_ms);
1054 }
1055 }
1056
1057 if (_max_rs_lengths > 0) {
1058 double cards_per_entry_ratio =
1059 (double) cards_scanned / (double) _max_rs_lengths;
1060 if (collector_state()->last_gc_was_young()) {
1061 _young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
1062 } else {
1063 _mixed_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
1064 }
1065 }
1066
1067 // This is defensive. For a while _max_rs_lengths could get
1068 // smaller than _recorded_rs_lengths which was causing
1069 // rs_length_diff to get very large and mess up the RSet length
1070 // predictions. The reason was unsafe concurrent updates to the
1071 // _inc_cset_recorded_rs_lengths field which the code below guards
1072 // against (see CR 7118202). This bug has now been fixed (see CR
1073 // 7119027). However, I'm still worried that
1074 // _inc_cset_recorded_rs_lengths might still end up somewhat
1075 // inaccurate. The concurrent refinement thread calculates an
1076 // RSet's length concurrently with other CR threads updating it
1077 // which might cause it to calculate the length incorrectly (if,
1078 // say, it's in mid-coarsening). So I'll leave in the defensive
1079 // conditional below just in case.
1080 size_t rs_length_diff = 0;
1081 if (_max_rs_lengths > _recorded_rs_lengths) {
1082 rs_length_diff = _max_rs_lengths - _recorded_rs_lengths;
1083 }
1084 _rs_length_diff_seq->add((double) rs_length_diff);
1085
1086 size_t freed_bytes = _heap_used_bytes_before_gc - cur_used_bytes;
1087 size_t copied_bytes = _collection_set_bytes_used_before - freed_bytes;
1088 double cost_per_byte_ms = 0.0;
1089
1090 if (copied_bytes > 0) {
1091 cost_per_byte_ms = average_time_ms(G1GCPhaseTimes::ObjCopy) / (double) copied_bytes;
1092 if (collector_state()->in_marking_window()) {
1093 _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms);
1094 } else {
1095 _cost_per_byte_ms_seq->add(cost_per_byte_ms);
1096 }
1097 }
1098
1099 double all_other_time_ms = pause_time_ms -
1100 (average_time_ms(G1GCPhaseTimes::UpdateRS) + average_time_ms(G1GCPhaseTimes::ScanRS) +
1101 average_time_ms(G1GCPhaseTimes::ObjCopy) + average_time_ms(G1GCPhaseTimes::Termination));
1102
1103 double young_other_time_ms = 0.0;
1104 if (young_cset_region_length() > 0) {
1105 young_other_time_ms =
1106 phase_times()->young_cset_choice_time_ms() +
1107 phase_times()->young_free_cset_time_ms();
1108 _young_other_cost_per_region_ms_seq->add(young_other_time_ms /
1109 (double) young_cset_region_length());
1110 }
1111 double non_young_other_time_ms = 0.0;
1112 if (old_cset_region_length() > 0) {
1113 non_young_other_time_ms =
1114 phase_times()->non_young_cset_choice_time_ms() +
1115 phase_times()->non_young_free_cset_time_ms();
1116
1117 _non_young_other_cost_per_region_ms_seq->add(non_young_other_time_ms /
1118 (double) old_cset_region_length());
1119 }
1120
1121 double constant_other_time_ms = all_other_time_ms -
1122 (young_other_time_ms + non_young_other_time_ms);
1123 _constant_other_time_ms_seq->add(constant_other_time_ms);
1124
1125 double survival_ratio = 0.0;
1126 if (_collection_set_bytes_used_before > 0) {
1127 survival_ratio = (double) _bytes_copied_during_gc /
1128 (double) _collection_set_bytes_used_before;
1129 }
1130
1131 _pending_cards_seq->add((double) _pending_cards);
1132 _rs_lengths_seq->add((double) _max_rs_lengths);
1133 }
1134
1135 collector_state()->set_in_marking_window(new_in_marking_window);
1136 collector_state()->set_in_marking_window_im(new_in_marking_window_im);
1137 _free_regions_at_end_of_collection = _g1->num_free_regions();
1138 update_young_list_max_and_target_length();
1139 update_rs_lengths_prediction();
1140
1141 // Note that _mmu_tracker->max_gc_time() returns the time in seconds.
1142 double update_rs_time_goal_ms = _mmu_tracker->max_gc_time() * MILLIUNITS * G1RSetUpdatingPauseTimePercent / 100.0;
1143
1144 double scan_hcc_time_ms = average_time_ms(G1GCPhaseTimes::ScanHCC);
1145
1146 if (update_rs_time_goal_ms < scan_hcc_time_ms) {
1147 log_debug(gc, ergo, refine)("Adjust concurrent refinement thresholds (scanning the HCC expected to take longer than Update RS time goal)."
1148 "Update RS time goal: %1.2fms Scan HCC time: %1.2fms",
1149 update_rs_time_goal_ms, scan_hcc_time_ms);
1150
1151 update_rs_time_goal_ms = 0;
1152 } else {
1153 update_rs_time_goal_ms -= scan_hcc_time_ms;
1154 }
1155 adjust_concurrent_refinement(average_time_ms(G1GCPhaseTimes::UpdateRS) - scan_hcc_time_ms,
1156 phase_times()->sum_thread_work_items(G1GCPhaseTimes::UpdateRS),
1157 update_rs_time_goal_ms);
1158
1159 _collectionSetChooser->verify();
1160 }
1161
1162 #define EXT_SIZE_FORMAT "%.1f%s"
1163 #define EXT_SIZE_PARAMS(bytes) \
1164 byte_size_in_proper_unit((double)(bytes)), \
1165 proper_unit_for_byte_size((bytes))
1166
1167 void G1CollectorPolicy::record_heap_size_info_at_start(bool full) {
1168 YoungList* young_list = _g1->young_list();
1169 _eden_used_bytes_before_gc = young_list->eden_used_bytes();
1170 _survivor_used_bytes_before_gc = young_list->survivor_used_bytes();
1171 _heap_capacity_bytes_before_gc = _g1->capacity();
1172 _heap_used_bytes_before_gc = _g1->used();
1173 _old_used_bytes_before_gc = _heap_used_bytes_before_gc - _survivor_used_bytes_before_gc - _eden_used_bytes_before_gc;
1174 _cur_collection_pause_used_regions_at_start = _g1->num_used_regions();
1175
1176 _eden_capacity_bytes_before_gc =
1177 (_young_list_target_length * HeapRegion::GrainBytes) - _survivor_used_bytes_before_gc;
1178
1179 _metaspace_used_bytes_before_gc = MetaspaceAux::used_bytes();
1180 }
1181
1182 void G1CollectorPolicy::print_detailed_heap_transition() const {
1183 YoungList* young_list = _g1->young_list();
1184
1185 size_t eden_used_bytes_after_gc = young_list->eden_used_bytes();
1186 size_t survivor_used_bytes_after_gc = young_list->survivor_used_bytes();
1187 size_t old_used_bytes_after_gc = _g1->used() - eden_used_bytes_after_gc - eden_used_bytes_after_gc;
1188
1189 size_t heap_capacity_bytes_after_gc = _g1->capacity();
1190 size_t eden_capacity_bytes_after_gc =
1191 (_young_list_target_length * HeapRegion::GrainBytes) - survivor_used_bytes_after_gc;
1192 size_t survivor_capacity_bytes_after_gc = _max_survivor_regions * HeapRegion::GrainBytes;
1193
1194 log_info(gc, heap)("Eden: " SIZE_FORMAT "K->" SIZE_FORMAT "K(" SIZE_FORMAT "K)",
1195 _eden_used_bytes_before_gc / K, eden_used_bytes_after_gc /K, eden_capacity_bytes_after_gc /K);
1196
1197 log_info(gc, heap)("Survivor: " SIZE_FORMAT "K->" SIZE_FORMAT "K(" SIZE_FORMAT "K)",
1198 _survivor_used_bytes_before_gc / K, survivor_used_bytes_after_gc /K, survivor_capacity_bytes_after_gc /K);
1199
1200 log_info(gc, heap)("Old: " SIZE_FORMAT "K->" SIZE_FORMAT "K(" SIZE_FORMAT "K)",
1201 _old_used_bytes_before_gc / K, old_used_bytes_after_gc /K, heap_capacity_bytes_after_gc /K);
1202
1203 MetaspaceAux::print_metaspace_change(_metaspace_used_bytes_before_gc);
1204 }
1205
1206 void G1CollectorPolicy::print_phases(double pause_time_sec) {
1207 phase_times()->print(pause_time_sec);
1208 }
1209
1210 void G1CollectorPolicy::adjust_concurrent_refinement(double update_rs_time,
1211 double update_rs_processed_buffers,
1212 double goal_ms) {
1213 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
1214 ConcurrentG1Refine *cg1r = G1CollectedHeap::heap()->concurrent_g1_refine();
1215
1216 if (G1UseAdaptiveConcRefinement) {
1217 const int k_gy = 3, k_gr = 6;
1218 const double inc_k = 1.1, dec_k = 0.9;
1219
1220 int g = cg1r->green_zone();
1221 if (update_rs_time > goal_ms) {
1222 g = (int)(g * dec_k); // Can become 0, that's OK. That would mean a mutator-only processing.
1223 } else {
1224 if (update_rs_time < goal_ms && update_rs_processed_buffers > g) {
1225 g = (int)MAX2(g * inc_k, g + 1.0);
1226 }
1227 }
1228 // Change the refinement threads params
1229 cg1r->set_green_zone(g);
1230 cg1r->set_yellow_zone(g * k_gy);
1231 cg1r->set_red_zone(g * k_gr);
1232 cg1r->reinitialize_threads();
1233
1234 int processing_threshold_delta = MAX2((int)(cg1r->green_zone() * _predictor.sigma()), 1);
1235 int processing_threshold = MIN2(cg1r->green_zone() + processing_threshold_delta,
1236 cg1r->yellow_zone());
1237 // Change the barrier params
1238 dcqs.set_process_completed_threshold(processing_threshold);
1239 dcqs.set_max_completed_queue(cg1r->red_zone());
1240 }
1241
1242 int curr_queue_size = dcqs.completed_buffers_num();
1243 if (curr_queue_size >= cg1r->yellow_zone()) {
1244 dcqs.set_completed_queue_padding(curr_queue_size);
1245 } else {
1246 dcqs.set_completed_queue_padding(0);
1247 }
1248 dcqs.notify_if_necessary();
1249 }
1250
1251 size_t G1CollectorPolicy::predict_rs_length_diff() const {
1252 return (size_t) get_new_prediction(_rs_length_diff_seq);
1253 }
1254
1255 double G1CollectorPolicy::predict_alloc_rate_ms() const {
1256 return get_new_prediction(_alloc_rate_ms_seq);
1257 }
1258
1259 double G1CollectorPolicy::predict_cost_per_card_ms() const {
1260 return get_new_prediction(_cost_per_card_ms_seq);
1261 }
1262
1263 double G1CollectorPolicy::predict_scan_hcc_ms() const {
1264 return get_new_prediction(_cost_scan_hcc_seq);
1265 }
1266
1267 double G1CollectorPolicy::predict_rs_update_time_ms(size_t pending_cards) const {
1268 return pending_cards * predict_cost_per_card_ms() + predict_scan_hcc_ms();
1269 }
1270
1271 double G1CollectorPolicy::predict_young_cards_per_entry_ratio() const {
1272 return get_new_prediction(_young_cards_per_entry_ratio_seq);
1273 }
1274
1275 double G1CollectorPolicy::predict_mixed_cards_per_entry_ratio() const {
1276 if (_mixed_cards_per_entry_ratio_seq->num() < 2) {
1277 return predict_young_cards_per_entry_ratio();
1278 } else {
1279 return get_new_prediction(_mixed_cards_per_entry_ratio_seq);
1280 }
1281 }
1282
1283 size_t G1CollectorPolicy::predict_young_card_num(size_t rs_length) const {
1284 return (size_t) (rs_length * predict_young_cards_per_entry_ratio());
1285 }
1286
1287 size_t G1CollectorPolicy::predict_non_young_card_num(size_t rs_length) const {
1288 return (size_t)(rs_length * predict_mixed_cards_per_entry_ratio());
1289 }
1290
1291 double G1CollectorPolicy::predict_rs_scan_time_ms(size_t card_num) const {
1292 if (collector_state()->gcs_are_young()) {
1293 return card_num * get_new_prediction(_cost_per_entry_ms_seq);
1294 } else {
1295 return predict_mixed_rs_scan_time_ms(card_num);
1296 }
1297 }
1298
1299 double G1CollectorPolicy::predict_mixed_rs_scan_time_ms(size_t card_num) const {
1300 if (_mixed_cost_per_entry_ms_seq->num() < 3) {
1301 return card_num * get_new_prediction(_cost_per_entry_ms_seq);
1302 } else {
1303 return card_num * get_new_prediction(_mixed_cost_per_entry_ms_seq);
1304 }
1305 }
1306
1307 double G1CollectorPolicy::predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) const {
1308 if (_cost_per_byte_ms_during_cm_seq->num() < 3) {
1309 return (1.1 * bytes_to_copy) * get_new_prediction(_cost_per_byte_ms_seq);
1310 } else {
1311 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_during_cm_seq);
1312 }
1313 }
1314
1315 double G1CollectorPolicy::predict_object_copy_time_ms(size_t bytes_to_copy) const {
1316 if (collector_state()->during_concurrent_mark()) {
1317 return predict_object_copy_time_ms_during_cm(bytes_to_copy);
1318 } else {
1319 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_seq);
1320 }
1321 }
1322
1323 double G1CollectorPolicy::predict_constant_other_time_ms() const {
1324 return get_new_prediction(_constant_other_time_ms_seq);
1325 }
1326
1327 double G1CollectorPolicy::predict_young_other_time_ms(size_t young_num) const {
1328 return young_num * get_new_prediction(_young_other_cost_per_region_ms_seq);
1329 }
1330
1331 double G1CollectorPolicy::predict_non_young_other_time_ms(size_t non_young_num) const {
1332 return non_young_num * get_new_prediction(_non_young_other_cost_per_region_ms_seq);
1333 }
1334
1335 double G1CollectorPolicy::predict_remark_time_ms() const {
1336 return get_new_prediction(_concurrent_mark_remark_times_ms);
1337 }
1338
1339 double G1CollectorPolicy::predict_cleanup_time_ms() const {
1340 return get_new_prediction(_concurrent_mark_cleanup_times_ms);
1341 }
1342
1343 double G1CollectorPolicy::predict_yg_surv_rate(int age, SurvRateGroup* surv_rate_group) const {
1344 TruncatedSeq* seq = surv_rate_group->get_seq(age);
1345 guarantee(seq->num() > 0, "There should be some young gen survivor samples available. Tried to access with age %d", age);
1346 double pred = get_new_prediction(seq);
1347 if (pred > 1.0) {
1348 pred = 1.0;
1349 }
1350 return pred;
1351 }
1352
1353 double G1CollectorPolicy::predict_yg_surv_rate(int age) const {
1354 return predict_yg_surv_rate(age, _short_lived_surv_rate_group);
1355 }
1356
1357 double G1CollectorPolicy::accum_yg_surv_rate_pred(int age) const {
1358 return _short_lived_surv_rate_group->accum_surv_rate_pred(age);
1359 }
1360
1361 double G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards,
1362 size_t scanned_cards) const {
1363 return
1364 predict_rs_update_time_ms(pending_cards) +
1365 predict_rs_scan_time_ms(scanned_cards) +
1366 predict_constant_other_time_ms();
1367 }
1368
1369 double G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards) const {
1370 size_t rs_length = predict_rs_length_diff();
1371 size_t card_num;
1372 if (collector_state()->gcs_are_young()) {
1373 card_num = predict_young_card_num(rs_length);
1374 } else {
1375 card_num = predict_non_young_card_num(rs_length);
1376 }
1377 return predict_base_elapsed_time_ms(pending_cards, card_num);
1378 }
1379
1380 size_t G1CollectorPolicy::predict_bytes_to_copy(HeapRegion* hr) const {
1381 size_t bytes_to_copy;
1382 if (hr->is_marked())
1383 bytes_to_copy = hr->max_live_bytes();
1384 else {
1385 assert(hr->is_young() && hr->age_in_surv_rate_group() != -1, "invariant");
1386 int age = hr->age_in_surv_rate_group();
1387 double yg_surv_rate = predict_yg_surv_rate(age, hr->surv_rate_group());
1388 bytes_to_copy = (size_t) (hr->used() * yg_surv_rate);
1389 }
1390 return bytes_to_copy;
1391 }
1392
1393 double G1CollectorPolicy::predict_region_elapsed_time_ms(HeapRegion* hr,
1394 bool for_young_gc) const {
1395 size_t rs_length = hr->rem_set()->occupied();
1396 size_t card_num;
1397
1398 // Predicting the number of cards is based on which type of GC
1399 // we're predicting for.
1400 if (for_young_gc) {
1401 card_num = predict_young_card_num(rs_length);
1402 } else {
1403 card_num = predict_non_young_card_num(rs_length);
1404 }
1405 size_t bytes_to_copy = predict_bytes_to_copy(hr);
1406
1407 double region_elapsed_time_ms =
1408 predict_rs_scan_time_ms(card_num) +
1409 predict_object_copy_time_ms(bytes_to_copy);
1410
1411 // The prediction of the "other" time for this region is based
1412 // upon the region type and NOT the GC type.
1413 if (hr->is_young()) {
1414 region_elapsed_time_ms += predict_young_other_time_ms(1);
1415 } else {
1416 region_elapsed_time_ms += predict_non_young_other_time_ms(1);
1417 }
1418 return region_elapsed_time_ms;
1419 }
1420
1421 void G1CollectorPolicy::init_cset_region_lengths(uint eden_cset_region_length,
1422 uint survivor_cset_region_length) {
1423 _eden_cset_region_length = eden_cset_region_length;
1424 _survivor_cset_region_length = survivor_cset_region_length;
1425 _old_cset_region_length = 0;
1426 }
1427
1428 void G1CollectorPolicy::set_recorded_rs_lengths(size_t rs_lengths) {
1429 _recorded_rs_lengths = rs_lengths;
1430 }
1431
1432 void G1CollectorPolicy::update_recent_gc_times(double end_time_sec,
1433 double elapsed_ms) {
1434 _recent_gc_times_ms->add(elapsed_ms);
1435 _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec);
1436 _prev_collection_pause_end_ms = end_time_sec * 1000.0;
1437 }
1438
1439 size_t G1CollectorPolicy::expansion_amount() const {
1440 double recent_gc_overhead = recent_avg_pause_time_ratio() * 100.0;
1441 double threshold = _gc_overhead_perc;
1442 if (recent_gc_overhead > threshold) {
1443 // We will double the existing space, or take
1444 // G1ExpandByPercentOfAvailable % of the available expansion
1445 // space, whichever is smaller, bounded below by a minimum
1446 // expansion (unless that's all that's left.)
1447 const size_t min_expand_bytes = 1*M;
1448 size_t reserved_bytes = _g1->max_capacity();
1449 size_t committed_bytes = _g1->capacity();
1450 size_t uncommitted_bytes = reserved_bytes - committed_bytes;
1451 size_t expand_bytes;
1452 size_t expand_bytes_via_pct =
1453 uncommitted_bytes * G1ExpandByPercentOfAvailable / 100;
1454 expand_bytes = MIN2(expand_bytes_via_pct, committed_bytes);
1455 expand_bytes = MAX2(expand_bytes, min_expand_bytes);
1456 expand_bytes = MIN2(expand_bytes, uncommitted_bytes);
1457
1458 log_debug(gc, ergo, heap)("Attempt heap expansion (recent GC overhead higher than threshold after GC) "
1459 "recent GC overhead: %1.2f %% threshold: %1.2f %% uncommitted: " SIZE_FORMAT "B calculated expansion amount: " SIZE_FORMAT "B (" INTX_FORMAT "%%)",
1460 recent_gc_overhead, threshold, uncommitted_bytes, expand_bytes_via_pct, G1ExpandByPercentOfAvailable);
1461
1462 return expand_bytes;
1463 } else {
1464 return 0;
1465 }
1466 }
1467
1468 void G1CollectorPolicy::print_tracing_info() const {
1469 _trace_young_gen_time_data.print();
1470 _trace_old_gen_time_data.print();
1471 }
1472
1473 void G1CollectorPolicy::print_yg_surv_rate_info() const {
1474 #ifndef PRODUCT
1475 _short_lived_surv_rate_group->print_surv_rate_summary();
1476 // add this call for any other surv rate groups
1477 #endif // PRODUCT
1478 }
1479
1480 bool G1CollectorPolicy::is_young_list_full() const {
1481 uint young_list_length = _g1->young_list()->length();
1482 uint young_list_target_length = _young_list_target_length;
1483 return young_list_length >= young_list_target_length;
1484 }
1485
1486 bool G1CollectorPolicy::can_expand_young_list() const {
1487 uint young_list_length = _g1->young_list()->length();
1488 uint young_list_max_length = _young_list_max_length;
1489 return young_list_length < young_list_max_length;
1490 }
1491
1492 void G1CollectorPolicy::update_max_gc_locker_expansion() {
1493 uint expansion_region_num = 0;
1494 if (GCLockerEdenExpansionPercent > 0) {
1495 double perc = (double) GCLockerEdenExpansionPercent / 100.0;
1496 double expansion_region_num_d = perc * (double) _young_list_target_length;
1497 // We use ceiling so that if expansion_region_num_d is > 0.0 (but
1498 // less than 1.0) we'll get 1.
1499 expansion_region_num = (uint) ceil(expansion_region_num_d);
1500 } else {
1501 assert(expansion_region_num == 0, "sanity");
1502 }
1503 _young_list_max_length = _young_list_target_length + expansion_region_num;
1504 assert(_young_list_target_length <= _young_list_max_length, "post-condition");
1505 }
1506
1507 // Calculates survivor space parameters.
1508 void G1CollectorPolicy::update_survivors_policy() {
1509 double max_survivor_regions_d =
1510 (double) _young_list_target_length / (double) SurvivorRatio;
1511 // We use ceiling so that if max_survivor_regions_d is > 0.0 (but
1512 // smaller than 1.0) we'll get 1.
1513 _max_survivor_regions = (uint) ceil(max_survivor_regions_d);
1514
1515 _tenuring_threshold = _survivors_age_table.compute_tenuring_threshold(
1516 HeapRegion::GrainWords * _max_survivor_regions, counters());
1517 }
1518
1519 bool G1CollectorPolicy::force_initial_mark_if_outside_cycle(
1520 GCCause::Cause gc_cause) {
1521 bool during_cycle = _g1->concurrent_mark()->cmThread()->during_cycle();
1522 if (!during_cycle) {
1523 log_debug(gc, ergo, conc)("Request concurrent cycle initiation (requested by GC cause). GC cause: %s", GCCause::to_string(gc_cause));
1524 collector_state()->set_initiate_conc_mark_if_possible(true);
1525 return true;
1526 } else {
1527 log_debug(gc, ergo, conc)("Do not request concurrent cycle initiation (concurrent cycle already in progress). GC cause: %s", GCCause::to_string(gc_cause));
1528 return false;
1529 }
1530 }
1531
1532 void
1533 G1CollectorPolicy::decide_on_conc_mark_initiation() {
1534 // We are about to decide on whether this pause will be an
1535 // initial-mark pause.
1536
1537 // First, collector_state()->during_initial_mark_pause() should not be already set. We
1538 // will set it here if we have to. However, it should be cleared by
1539 // the end of the pause (it's only set for the duration of an
1540 // initial-mark pause).
1541 assert(!collector_state()->during_initial_mark_pause(), "pre-condition");
1542
1543 if (collector_state()->initiate_conc_mark_if_possible()) {
1544 // We had noticed on a previous pause that the heap occupancy has
1545 // gone over the initiating threshold and we should start a
1546 // concurrent marking cycle. So we might initiate one.
1547
1548 bool during_cycle = _g1->concurrent_mark()->cmThread()->during_cycle();
1549 if (!during_cycle) {
1550 // The concurrent marking thread is not "during a cycle", i.e.,
1551 // it has completed the last one. So we can go ahead and
1552 // initiate a new cycle.
1553
1554 collector_state()->set_during_initial_mark_pause(true);
1555 // We do not allow mixed GCs during marking.
1556 if (!collector_state()->gcs_are_young()) {
1557 collector_state()->set_gcs_are_young(true);
1558 log_debug(gc, ergo)("End mixed GCs (concurrent cycle is about to start");
1559 }
1560
1561 // And we can now clear initiate_conc_mark_if_possible() as
1562 // we've already acted on it.
1563 collector_state()->set_initiate_conc_mark_if_possible(false);
1564 log_debug(gc, ergo, conc)("Initiate concurrent cycle (concurrent cycle initiation requested)");
1565 } else {
1566 // The concurrent marking thread is still finishing up the
1567 // previous cycle. If we start one right now the two cycles
1568 // overlap. In particular, the concurrent marking thread might
1569 // be in the process of clearing the next marking bitmap (which
1570 // we will use for the next cycle if we start one). Starting a
1571 // cycle now will be bad given that parts of the marking
1572 // information might get cleared by the marking thread. And we
1573 // cannot wait for the marking thread to finish the cycle as it
1574 // periodically yields while clearing the next marking bitmap
1575 // and, if it's in a yield point, it's waiting for us to
1576 // finish. So, at this point we will not start a cycle and we'll
1577 // let the concurrent marking thread complete the last one.
1578 log_debug(gc, ergo, conc)("Do not initiate concurrent cycle (concurrent cycle already in progress)");
1579 }
1580 }
1581 }
1582
1583 class ParKnownGarbageHRClosure: public HeapRegionClosure {
1584 G1CollectedHeap* _g1h;
1585 CSetChooserParUpdater _cset_updater;
1586
1587 public:
1588 ParKnownGarbageHRClosure(CollectionSetChooser* hrSorted,
1589 uint chunk_size) :
1590 _g1h(G1CollectedHeap::heap()),
1591 _cset_updater(hrSorted, true /* parallel */, chunk_size) { }
1592
1593 bool doHeapRegion(HeapRegion* r) {
1594 // Do we have any marking information for this region?
1595 if (r->is_marked()) {
1596 // We will skip any region that's currently used as an old GC
1597 // alloc region (we should not consider those for collection
1598 // before we fill them up).
1599 if (_cset_updater.should_add(r) && !_g1h->is_old_gc_alloc_region(r)) {
1600 _cset_updater.add_region(r);
1601 }
1602 }
1603 return false;
1604 }
1605 };
1606
1607 class ParKnownGarbageTask: public AbstractGangTask {
1608 CollectionSetChooser* _hrSorted;
1609 uint _chunk_size;
1610 G1CollectedHeap* _g1;
1611 HeapRegionClaimer _hrclaimer;
1612
1613 public:
1614 ParKnownGarbageTask(CollectionSetChooser* hrSorted, uint chunk_size, uint n_workers) :
1615 AbstractGangTask("ParKnownGarbageTask"),
1616 _hrSorted(hrSorted), _chunk_size(chunk_size),
1617 _g1(G1CollectedHeap::heap()), _hrclaimer(n_workers) {}
1618
1619 void work(uint worker_id) {
1620 ParKnownGarbageHRClosure parKnownGarbageCl(_hrSorted, _chunk_size);
1621 _g1->heap_region_par_iterate(&parKnownGarbageCl, worker_id, &_hrclaimer);
1622 }
1623 };
1624
1625 uint G1CollectorPolicy::calculate_parallel_work_chunk_size(uint n_workers, uint n_regions) const {
1626 assert(n_workers > 0, "Active gc workers should be greater than 0");
1627 const uint overpartition_factor = 4;
1628 const uint min_chunk_size = MAX2(n_regions / n_workers, 1U);
1629 return MAX2(n_regions / (n_workers * overpartition_factor), min_chunk_size);
1630 }
1631
1632 void
1633 G1CollectorPolicy::record_concurrent_mark_cleanup_end() {
1634 _collectionSetChooser->clear();
1635
1636 WorkGang* workers = _g1->workers();
1637 uint n_workers = workers->active_workers();
1638
1639 uint n_regions = _g1->num_regions();
1640 uint chunk_size = calculate_parallel_work_chunk_size(n_workers, n_regions);
1641 _collectionSetChooser->prepare_for_par_region_addition(n_workers, n_regions, chunk_size);
1642 ParKnownGarbageTask par_known_garbage_task(_collectionSetChooser, chunk_size, n_workers);
1643 workers->run_task(&par_known_garbage_task);
1644
1645 _collectionSetChooser->sort_regions();
1646
1647 double end_sec = os::elapsedTime();
1648 double elapsed_time_ms = (end_sec - _mark_cleanup_start_sec) * 1000.0;
1649 _concurrent_mark_cleanup_times_ms->add(elapsed_time_ms);
1650 _cur_mark_stop_world_time_ms += elapsed_time_ms;
1651 _prev_collection_pause_end_ms += elapsed_time_ms;
1652 _mmu_tracker->add_pause(_mark_cleanup_start_sec, end_sec);
1653 }
1654
1655 // Add the heap region at the head of the non-incremental collection set
1656 void G1CollectorPolicy::add_old_region_to_cset(HeapRegion* hr) {
1657 assert(_inc_cset_build_state == Active, "Precondition");
1658 assert(hr->is_old(), "the region should be old");
1659
1660 assert(!hr->in_collection_set(), "should not already be in the CSet");
1661 _g1->register_old_region_with_cset(hr);
1662 hr->set_next_in_collection_set(_collection_set);
1663 _collection_set = hr;
1664 _collection_set_bytes_used_before += hr->used();
1665 size_t rs_length = hr->rem_set()->occupied();
1666 _recorded_rs_lengths += rs_length;
1667 _old_cset_region_length += 1;
1668 }
1669
1670 // Initialize the per-collection-set information
1671 void G1CollectorPolicy::start_incremental_cset_building() {
1672 assert(_inc_cset_build_state == Inactive, "Precondition");
1673
1674 _inc_cset_head = NULL;
1675 _inc_cset_tail = NULL;
1676 _inc_cset_bytes_used_before = 0;
1677
1678 _inc_cset_max_finger = 0;
1679 _inc_cset_recorded_rs_lengths = 0;
1680 _inc_cset_recorded_rs_lengths_diffs = 0;
1681 _inc_cset_predicted_elapsed_time_ms = 0.0;
1682 _inc_cset_predicted_elapsed_time_ms_diffs = 0.0;
1683 _inc_cset_build_state = Active;
1684 }
1685
1686 void G1CollectorPolicy::finalize_incremental_cset_building() {
1687 assert(_inc_cset_build_state == Active, "Precondition");
1688 assert(SafepointSynchronize::is_at_safepoint(), "should be at a safepoint");
1689
1690 // The two "main" fields, _inc_cset_recorded_rs_lengths and
1691 // _inc_cset_predicted_elapsed_time_ms, are updated by the thread
1692 // that adds a new region to the CSet. Further updates by the
1693 // concurrent refinement thread that samples the young RSet lengths
1694 // are accumulated in the *_diffs fields. Here we add the diffs to
1695 // the "main" fields.
1696
1697 if (_inc_cset_recorded_rs_lengths_diffs >= 0) {
1698 _inc_cset_recorded_rs_lengths += _inc_cset_recorded_rs_lengths_diffs;
1699 } else {
1700 // This is defensive. The diff should in theory be always positive
1701 // as RSets can only grow between GCs. However, given that we
1702 // sample their size concurrently with other threads updating them
1703 // it's possible that we might get the wrong size back, which
1704 // could make the calculations somewhat inaccurate.
1705 size_t diffs = (size_t) (-_inc_cset_recorded_rs_lengths_diffs);
1706 if (_inc_cset_recorded_rs_lengths >= diffs) {
1707 _inc_cset_recorded_rs_lengths -= diffs;
1708 } else {
1709 _inc_cset_recorded_rs_lengths = 0;
1710 }
1711 }
1712 _inc_cset_predicted_elapsed_time_ms +=
1713 _inc_cset_predicted_elapsed_time_ms_diffs;
1714
1715 _inc_cset_recorded_rs_lengths_diffs = 0;
1716 _inc_cset_predicted_elapsed_time_ms_diffs = 0.0;
1717 }
1718
1719 void G1CollectorPolicy::add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length) {
1720 // This routine is used when:
1721 // * adding survivor regions to the incremental cset at the end of an
1722 // evacuation pause,
1723 // * adding the current allocation region to the incremental cset
1724 // when it is retired, and
1725 // * updating existing policy information for a region in the
1726 // incremental cset via young list RSet sampling.
1727 // Therefore this routine may be called at a safepoint by the
1728 // VM thread, or in-between safepoints by mutator threads (when
1729 // retiring the current allocation region) or a concurrent
1730 // refine thread (RSet sampling).
1731
1732 double region_elapsed_time_ms = predict_region_elapsed_time_ms(hr, collector_state()->gcs_are_young());
1733 size_t used_bytes = hr->used();
1734 _inc_cset_recorded_rs_lengths += rs_length;
1735 _inc_cset_predicted_elapsed_time_ms += region_elapsed_time_ms;
1736 _inc_cset_bytes_used_before += used_bytes;
1737
1738 // Cache the values we have added to the aggregated information
1739 // in the heap region in case we have to remove this region from
1740 // the incremental collection set, or it is updated by the
1741 // rset sampling code
1742 hr->set_recorded_rs_length(rs_length);
1743 hr->set_predicted_elapsed_time_ms(region_elapsed_time_ms);
1744 }
1745
1746 void G1CollectorPolicy::update_incremental_cset_info(HeapRegion* hr,
1747 size_t new_rs_length) {
1748 // Update the CSet information that is dependent on the new RS length
1749 assert(hr->is_young(), "Precondition");
1750 assert(!SafepointSynchronize::is_at_safepoint(),
1751 "should not be at a safepoint");
1752
1753 // We could have updated _inc_cset_recorded_rs_lengths and
1754 // _inc_cset_predicted_elapsed_time_ms directly but we'd need to do
1755 // that atomically, as this code is executed by a concurrent
1756 // refinement thread, potentially concurrently with a mutator thread
1757 // allocating a new region and also updating the same fields. To
1758 // avoid the atomic operations we accumulate these updates on two
1759 // separate fields (*_diffs) and we'll just add them to the "main"
1760 // fields at the start of a GC.
1761
1762 ssize_t old_rs_length = (ssize_t) hr->recorded_rs_length();
1763 ssize_t rs_lengths_diff = (ssize_t) new_rs_length - old_rs_length;
1764 _inc_cset_recorded_rs_lengths_diffs += rs_lengths_diff;
1765
1766 double old_elapsed_time_ms = hr->predicted_elapsed_time_ms();
1767 double new_region_elapsed_time_ms = predict_region_elapsed_time_ms(hr, collector_state()->gcs_are_young());
1768 double elapsed_ms_diff = new_region_elapsed_time_ms - old_elapsed_time_ms;
1769 _inc_cset_predicted_elapsed_time_ms_diffs += elapsed_ms_diff;
1770
1771 hr->set_recorded_rs_length(new_rs_length);
1772 hr->set_predicted_elapsed_time_ms(new_region_elapsed_time_ms);
1773 }
1774
1775 void G1CollectorPolicy::add_region_to_incremental_cset_common(HeapRegion* hr) {
1776 assert(hr->is_young(), "invariant");
1777 assert(hr->young_index_in_cset() > -1, "should have already been set");
1778 assert(_inc_cset_build_state == Active, "Precondition");
1779
1780 // We need to clear and set the cached recorded/cached collection set
1781 // information in the heap region here (before the region gets added
1782 // to the collection set). An individual heap region's cached values
1783 // are calculated, aggregated with the policy collection set info,
1784 // and cached in the heap region here (initially) and (subsequently)
1785 // by the Young List sampling code.
1786
1787 size_t rs_length = hr->rem_set()->occupied();
1788 add_to_incremental_cset_info(hr, rs_length);
1789
1790 HeapWord* hr_end = hr->end();
1791 _inc_cset_max_finger = MAX2(_inc_cset_max_finger, hr_end);
1792
1793 assert(!hr->in_collection_set(), "invariant");
1794 _g1->register_young_region_with_cset(hr);
1795 assert(hr->next_in_collection_set() == NULL, "invariant");
1796 }
1797
1798 // Add the region at the RHS of the incremental cset
1799 void G1CollectorPolicy::add_region_to_incremental_cset_rhs(HeapRegion* hr) {
1800 // We should only ever be appending survivors at the end of a pause
1801 assert(hr->is_survivor(), "Logic");
1802
1803 // Do the 'common' stuff
1804 add_region_to_incremental_cset_common(hr);
1805
1806 // Now add the region at the right hand side
1807 if (_inc_cset_tail == NULL) {
1808 assert(_inc_cset_head == NULL, "invariant");
1809 _inc_cset_head = hr;
1810 } else {
1811 _inc_cset_tail->set_next_in_collection_set(hr);
1812 }
1813 _inc_cset_tail = hr;
1814 }
1815
1816 // Add the region to the LHS of the incremental cset
1817 void G1CollectorPolicy::add_region_to_incremental_cset_lhs(HeapRegion* hr) {
1818 // Survivors should be added to the RHS at the end of a pause
1819 assert(hr->is_eden(), "Logic");
1820
1821 // Do the 'common' stuff
1822 add_region_to_incremental_cset_common(hr);
1823
1824 // Add the region at the left hand side
1825 hr->set_next_in_collection_set(_inc_cset_head);
1826 if (_inc_cset_head == NULL) {
1827 assert(_inc_cset_tail == NULL, "Invariant");
1828 _inc_cset_tail = hr;
1829 }
1830 _inc_cset_head = hr;
1831 }
1832
1833 #ifndef PRODUCT
1834 void G1CollectorPolicy::print_collection_set(HeapRegion* list_head, outputStream* st) {
1835 assert(list_head == inc_cset_head() || list_head == collection_set(), "must be");
1836
1837 st->print_cr("\nCollection_set:");
1838 HeapRegion* csr = list_head;
1839 while (csr != NULL) {
1840 HeapRegion* next = csr->next_in_collection_set();
1841 assert(csr->in_collection_set(), "bad CS");
1842 st->print_cr(" " HR_FORMAT ", P: " PTR_FORMAT "N: " PTR_FORMAT ", age: %4d",
1843 HR_FORMAT_PARAMS(csr),
1844 p2i(csr->prev_top_at_mark_start()), p2i(csr->next_top_at_mark_start()),
1845 csr->age_in_surv_rate_group_cond());
1846 csr = next;
1847 }
1848 }
1849 #endif // !PRODUCT
1850
1851 double G1CollectorPolicy::reclaimable_bytes_perc(size_t reclaimable_bytes) const {
1852 // Returns the given amount of reclaimable bytes (that represents
1853 // the amount of reclaimable space still to be collected) as a
1854 // percentage of the current heap capacity.
1855 size_t capacity_bytes = _g1->capacity();
1856 return (double) reclaimable_bytes * 100.0 / (double) capacity_bytes;
1857 }
1858
1859 bool G1CollectorPolicy::next_gc_should_be_mixed(const char* true_action_str,
1860 const char* false_action_str) const {
1861 CollectionSetChooser* cset_chooser = _collectionSetChooser;
1862 if (cset_chooser->is_empty()) {
1863 log_debug(gc, ergo)("%s (candidate old regions not available)", false_action_str);
1864 return false;
1865 }
1866
1867 // Is the amount of uncollected reclaimable space above G1HeapWastePercent?
1868 size_t reclaimable_bytes = cset_chooser->remaining_reclaimable_bytes();
1869 double reclaimable_perc = reclaimable_bytes_perc(reclaimable_bytes);
1870 double threshold = (double) G1HeapWastePercent;
1871 if (reclaimable_perc <= threshold) {
1872 log_debug(gc, ergo)("%s (reclaimable percentage not over threshold). candidate old regions: %u reclaimable: " SIZE_FORMAT " (%1.2f) threshold: " UINTX_FORMAT,
1873 false_action_str, cset_chooser->remaining_regions(), reclaimable_bytes, reclaimable_perc, G1HeapWastePercent);
1874 return false;
1875 }
1876
1877 log_debug(gc, ergo)("%s (candidate old regions available). candidate old regions: %u reclaimable: " SIZE_FORMAT " (%1.2f) threshold: " UINTX_FORMAT,
1878 true_action_str, cset_chooser->remaining_regions(), reclaimable_bytes, reclaimable_perc, G1HeapWastePercent);
1879 return true;
1880 }
1881
1882 uint G1CollectorPolicy::calc_min_old_cset_length() const {
1883 // The min old CSet region bound is based on the maximum desired
1884 // number of mixed GCs after a cycle. I.e., even if some old regions
1885 // look expensive, we should add them to the CSet anyway to make
1886 // sure we go through the available old regions in no more than the
1887 // maximum desired number of mixed GCs.
1888 //
1889 // The calculation is based on the number of marked regions we added
1890 // to the CSet chooser in the first place, not how many remain, so
1891 // that the result is the same during all mixed GCs that follow a cycle.
1892
1893 const size_t region_num = (size_t) _collectionSetChooser->length();
1894 const size_t gc_num = (size_t) MAX2(G1MixedGCCountTarget, (uintx) 1);
1895 size_t result = region_num / gc_num;
1896 // emulate ceiling
1897 if (result * gc_num < region_num) {
1898 result += 1;
1899 }
1900 return (uint) result;
1901 }
1902
1903 uint G1CollectorPolicy::calc_max_old_cset_length() const {
1904 // The max old CSet region bound is based on the threshold expressed
1905 // as a percentage of the heap size. I.e., it should bound the
1906 // number of old regions added to the CSet irrespective of how many
1907 // of them are available.
1908
1909 const G1CollectedHeap* g1h = G1CollectedHeap::heap();
1910 const size_t region_num = g1h->num_regions();
1911 const size_t perc = (size_t) G1OldCSetRegionThresholdPercent;
1912 size_t result = region_num * perc / 100;
1913 // emulate ceiling
1914 if (100 * result < region_num * perc) {
1915 result += 1;
1916 }
1917 return (uint) result;
1918 }
1919
1920
1921 double G1CollectorPolicy::finalize_young_cset_part(double target_pause_time_ms) {
1922 double young_start_time_sec = os::elapsedTime();
1923
1924 YoungList* young_list = _g1->young_list();
1925 finalize_incremental_cset_building();
1926
1927 guarantee(target_pause_time_ms > 0.0,
1928 "target_pause_time_ms = %1.6lf should be positive", target_pause_time_ms);
1929 guarantee(_collection_set == NULL, "Precondition");
1930
1931 double base_time_ms = predict_base_elapsed_time_ms(_pending_cards);
1932 double time_remaining_ms = MAX2(target_pause_time_ms - base_time_ms, 0.0);
1933
1934 log_trace(gc, ergo, cset)("Start choosing CSet. pending cards: " SIZE_FORMAT " predicted base time: %1.2fms remaining time: %1.2fms target pause time: %1.2fms",
1935 _pending_cards, base_time_ms, time_remaining_ms, target_pause_time_ms);
1936
1937 collector_state()->set_last_gc_was_young(collector_state()->gcs_are_young());
1938
1939 if (collector_state()->last_gc_was_young()) {
1940 _trace_young_gen_time_data.increment_young_collection_count();
1941 } else {
1942 _trace_young_gen_time_data.increment_mixed_collection_count();
1943 }
1944
1945 // The young list is laid with the survivor regions from the previous
1946 // pause are appended to the RHS of the young list, i.e.
1947 // [Newly Young Regions ++ Survivors from last pause].
1948
1949 uint survivor_region_length = young_list->survivor_length();
1950 uint eden_region_length = young_list->eden_length();
1951 init_cset_region_lengths(eden_region_length, survivor_region_length);
1952
1953 HeapRegion* hr = young_list->first_survivor_region();
1954 while (hr != NULL) {
1955 assert(hr->is_survivor(), "badly formed young list");
1956 // There is a convention that all the young regions in the CSet
1957 // are tagged as "eden", so we do this for the survivors here. We
1958 // use the special set_eden_pre_gc() as it doesn't check that the
1959 // region is free (which is not the case here).
1960 hr->set_eden_pre_gc();
1961 hr = hr->get_next_young_region();
1962 }
1963
1964 // Clear the fields that point to the survivor list - they are all young now.
1965 young_list->clear_survivors();
1966
1967 _collection_set = _inc_cset_head;
1968 _collection_set_bytes_used_before = _inc_cset_bytes_used_before;
1969 time_remaining_ms = MAX2(time_remaining_ms - _inc_cset_predicted_elapsed_time_ms, 0.0);
1970
1971 log_trace(gc, ergo, cset)("Add young regions to CSet. eden: %u regions, survivors: %u regions, predicted young region time: %1.2fms, target pause time: %1.2fms",
1972 eden_region_length, survivor_region_length, _inc_cset_predicted_elapsed_time_ms, target_pause_time_ms);
1973
1974 // The number of recorded young regions is the incremental
1975 // collection set's current size
1976 set_recorded_rs_lengths(_inc_cset_recorded_rs_lengths);
1977
1978 double young_end_time_sec = os::elapsedTime();
1979 phase_times()->record_young_cset_choice_time_ms((young_end_time_sec - young_start_time_sec) * 1000.0);
1980
1981 return time_remaining_ms;
1982 }
1983
1984 void G1CollectorPolicy::finalize_old_cset_part(double time_remaining_ms) {
1985 double non_young_start_time_sec = os::elapsedTime();
1986 double predicted_old_time_ms = 0.0;
1987
1988
1989 if (!collector_state()->gcs_are_young()) {
1990 CollectionSetChooser* cset_chooser = _collectionSetChooser;
1991 cset_chooser->verify();
1992 const uint min_old_cset_length = calc_min_old_cset_length();
1993 const uint max_old_cset_length = calc_max_old_cset_length();
1994
1995 uint expensive_region_num = 0;
1996 bool check_time_remaining = adaptive_young_list_length();
1997
1998 HeapRegion* hr = cset_chooser->peek();
1999 while (hr != NULL) {
2000 if (old_cset_region_length() >= max_old_cset_length) {
2001 // Added maximum number of old regions to the CSet.
2002 log_debug(gc, ergo, cset)("Finish adding old regions to CSet (old CSet region num reached max). old %u regions, max %u regions",
2003 old_cset_region_length(), max_old_cset_length);
2004 break;
2005 }
2006
2007
2008 // Stop adding regions if the remaining reclaimable space is
2009 // not above G1HeapWastePercent.
2010 size_t reclaimable_bytes = cset_chooser->remaining_reclaimable_bytes();
2011 double reclaimable_perc = reclaimable_bytes_perc(reclaimable_bytes);
2012 double threshold = (double) G1HeapWastePercent;
2013 if (reclaimable_perc <= threshold) {
2014 // We've added enough old regions that the amount of uncollected
2015 // reclaimable space is at or below the waste threshold. Stop
2016 // adding old regions to the CSet.
2017 log_debug(gc, ergo, cset)("Finish adding old regions to CSet (reclaimable percentage not over threshold). "
2018 "old %u regions, max %u regions, reclaimable: " SIZE_FORMAT "B (%1.2f%%) threshold: " UINTX_FORMAT "%%",
2019 old_cset_region_length(), max_old_cset_length, reclaimable_bytes, reclaimable_perc, G1HeapWastePercent);
2020 break;
2021 }
2022
2023 double predicted_time_ms = predict_region_elapsed_time_ms(hr, collector_state()->gcs_are_young());
2024 if (check_time_remaining) {
2025 if (predicted_time_ms > time_remaining_ms) {
2026 // Too expensive for the current CSet.
2027
2028 if (old_cset_region_length() >= min_old_cset_length) {
2029 // We have added the minimum number of old regions to the CSet,
2030 // we are done with this CSet.
2031 log_debug(gc, ergo, cset)("Finish adding old regions to CSet (predicted time is too high). "
2032 "predicted time: %1.2fms, remaining time: %1.2fms old %u regions, min %u regions",
2033 predicted_time_ms, time_remaining_ms, old_cset_region_length(), min_old_cset_length);
2034 break;
2035 }
2036
2037 // We'll add it anyway given that we haven't reached the
2038 // minimum number of old regions.
2039 expensive_region_num += 1;
2040 }
2041 } else {
2042 if (old_cset_region_length() >= min_old_cset_length) {
2043 // In the non-auto-tuning case, we'll finish adding regions
2044 // to the CSet if we reach the minimum.
2045
2046 log_debug(gc, ergo, cset)("Finish adding old regions to CSet (old CSet region num reached min). old %u regions, min %u regions",
2047 old_cset_region_length(), min_old_cset_length);
2048 break;
2049 }
2050 }
2051
2052 // We will add this region to the CSet.
2053 time_remaining_ms = MAX2(time_remaining_ms - predicted_time_ms, 0.0);
2054 predicted_old_time_ms += predicted_time_ms;
2055 cset_chooser->pop(); // already have region via peek()
2056 _g1->old_set_remove(hr);
2057 add_old_region_to_cset(hr);
2058
2059 hr = cset_chooser->peek();
2060 }
2061 if (hr == NULL) {
2062 log_debug(gc, ergo, cset)("Finish adding old regions to CSet (candidate old regions not available)");
2063 }
2064
2065 if (expensive_region_num > 0) {
2066 // We print the information once here at the end, predicated on
2067 // whether we added any apparently expensive regions or not, to
2068 // avoid generating output per region.
2069 log_debug(gc, ergo, cset)("Added expensive regions to CSet (old CSet region num not reached min)."
2070 "old %u regions, expensive: %u regions, min %u regions, remaining time: %1.2fms",
2071 old_cset_region_length(), expensive_region_num, min_old_cset_length, time_remaining_ms);
2072 }
2073
2074 cset_chooser->verify();
2075 }
2076
2077 stop_incremental_cset_building();
2078
2079 log_debug(gc, ergo, cset)("Finish choosing CSet. old %u regions, predicted old region time: %1.2fms, time remaining: %1.2f",
2080 old_cset_region_length(), predicted_old_time_ms, time_remaining_ms);
2081
2082 double non_young_end_time_sec = os::elapsedTime();
2083 phase_times()->record_non_young_cset_choice_time_ms((non_young_end_time_sec - non_young_start_time_sec) * 1000.0);
2084 }
2085
2086 void TraceYoungGenTimeData::record_start_collection(double time_to_stop_the_world_ms) {
2087 if(TraceYoungGenTime) {
2088 _all_stop_world_times_ms.add(time_to_stop_the_world_ms);
2089 }
2090 }
2091
2092 void TraceYoungGenTimeData::record_yield_time(double yield_time_ms) {
2093 if(TraceYoungGenTime) {
2094 _all_yield_times_ms.add(yield_time_ms);
2095 }
2096 }
2097
2098 void TraceYoungGenTimeData::record_end_collection(double pause_time_ms, G1GCPhaseTimes* phase_times) {
2099 if(TraceYoungGenTime) {
2100 _total.add(pause_time_ms);
2101 _other.add(pause_time_ms - phase_times->accounted_time_ms());
2102 _root_region_scan_wait.add(phase_times->root_region_scan_wait_time_ms());
2103 _parallel.add(phase_times->cur_collection_par_time_ms());
2104 _ext_root_scan.add(phase_times->average_time_ms(G1GCPhaseTimes::ExtRootScan));
2105 _satb_filtering.add(phase_times->average_time_ms(G1GCPhaseTimes::SATBFiltering));
2106 _update_rs.add(phase_times->average_time_ms(G1GCPhaseTimes::UpdateRS));
2107 _scan_rs.add(phase_times->average_time_ms(G1GCPhaseTimes::ScanRS));
2108 _obj_copy.add(phase_times->average_time_ms(G1GCPhaseTimes::ObjCopy));
2109 _termination.add(phase_times->average_time_ms(G1GCPhaseTimes::Termination));
2110
2111 double parallel_known_time = phase_times->average_time_ms(G1GCPhaseTimes::ExtRootScan) +
2112 phase_times->average_time_ms(G1GCPhaseTimes::SATBFiltering) +
2113 phase_times->average_time_ms(G1GCPhaseTimes::UpdateRS) +
2114 phase_times->average_time_ms(G1GCPhaseTimes::ScanRS) +
2115 phase_times->average_time_ms(G1GCPhaseTimes::ObjCopy) +
2116 phase_times->average_time_ms(G1GCPhaseTimes::Termination);
2117
2118 double parallel_other_time = phase_times->cur_collection_par_time_ms() - parallel_known_time;
2119 _parallel_other.add(parallel_other_time);
2120 _clear_ct.add(phase_times->cur_clear_ct_time_ms());
2121 }
2122 }
2123
2124 void TraceYoungGenTimeData::increment_young_collection_count() {
2125 if(TraceYoungGenTime) {
2126 ++_young_pause_num;
2127 }
2128 }
2129
2130 void TraceYoungGenTimeData::increment_mixed_collection_count() {
2131 if(TraceYoungGenTime) {
2132 ++_mixed_pause_num;
2133 }
2134 }
2135
2136 void TraceYoungGenTimeData::print_summary(const char* str,
2137 const NumberSeq* seq) const {
2138 double sum = seq->sum();
2139 gclog_or_tty->print_cr("%-27s = %8.2lf s (avg = %8.2lf ms)",
2140 str, sum / 1000.0, seq->avg());
2141 }
2142
2143 void TraceYoungGenTimeData::print_summary_sd(const char* str,
2144 const NumberSeq* seq) const {
2145 print_summary(str, seq);
2146 gclog_or_tty->print_cr("%45s = %5d, std dev = %8.2lf ms, max = %8.2lf ms)",
2147 "(num", seq->num(), seq->sd(), seq->maximum());
2148 }
2149
2150 void TraceYoungGenTimeData::print() const {
2151 if (!TraceYoungGenTime) {
2152 return;
2153 }
2154
2155 gclog_or_tty->print_cr("ALL PAUSES");
2156 print_summary_sd(" Total", &_total);
2157 gclog_or_tty->cr();
2158 gclog_or_tty->cr();
2159 gclog_or_tty->print_cr(" Young GC Pauses: %8d", _young_pause_num);
2160 gclog_or_tty->print_cr(" Mixed GC Pauses: %8d", _mixed_pause_num);
2161 gclog_or_tty->cr();
2162
2163 gclog_or_tty->print_cr("EVACUATION PAUSES");
2164
2165 if (_young_pause_num == 0 && _mixed_pause_num == 0) {
2166 gclog_or_tty->print_cr("none");
2167 } else {
2168 print_summary_sd(" Evacuation Pauses", &_total);
2169 print_summary(" Root Region Scan Wait", &_root_region_scan_wait);
2170 print_summary(" Parallel Time", &_parallel);
2171 print_summary(" Ext Root Scanning", &_ext_root_scan);
2172 print_summary(" SATB Filtering", &_satb_filtering);
2173 print_summary(" Update RS", &_update_rs);
2174 print_summary(" Scan RS", &_scan_rs);
2175 print_summary(" Object Copy", &_obj_copy);
2176 print_summary(" Termination", &_termination);
2177 print_summary(" Parallel Other", &_parallel_other);
2178 print_summary(" Clear CT", &_clear_ct);
2179 print_summary(" Other", &_other);
2180 }
2181 gclog_or_tty->cr();
2182
2183 gclog_or_tty->print_cr("MISC");
2184 print_summary_sd(" Stop World", &_all_stop_world_times_ms);
2185 print_summary_sd(" Yields", &_all_yield_times_ms);
2186 }
2187
2188 void TraceOldGenTimeData::record_full_collection(double full_gc_time_ms) {
2189 if (TraceOldGenTime) {
2190 _all_full_gc_times.add(full_gc_time_ms);
2191 }
2192 }
2193
2194 void TraceOldGenTimeData::print() const {
2195 if (!TraceOldGenTime) {
2196 return;
2197 }
2198
2199 if (_all_full_gc_times.num() > 0) {
2200 gclog_or_tty->print("\n%4d full_gcs: total time = %8.2f s",
2201 _all_full_gc_times.num(),
2202 _all_full_gc_times.sum() / 1000.0);
2203 gclog_or_tty->print_cr(" (avg = %8.2fms).", _all_full_gc_times.avg());
2204 gclog_or_tty->print_cr(" [std. dev = %8.2f ms, max = %8.2f ms]",
2205 _all_full_gc_times.sd(),
2206 _all_full_gc_times.maximum());
2207 }
2208 }