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 #ifndef __clang_major__
26 // FIXME, formats have issues. Disable this macro definition, compile, and study warnings for more information.
27 #define ATTRIBUTE_PRINTF(x,y)
28 #endif
29
30 #include "precompiled.hpp"
31 #include "gc_implementation/g1/concurrentG1Refine.hpp"
32 #include "gc_implementation/g1/concurrentMark.hpp"
33 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
34 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
35 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
36 #include "gc_implementation/g1/g1ErgoVerbose.hpp"
37 #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
38 #include "gc_implementation/g1/g1Log.hpp"
39 #include "gc_implementation/g1/heapRegionRemSet.hpp"
40 #include "gc_implementation/shared/gcPolicyCounters.hpp"
41 #include "runtime/arguments.hpp"
42 #include "runtime/java.hpp"
43 #include "runtime/mutexLocker.hpp"
44 #include "utilities/debug.hpp"
45
46 // Different defaults for different number of GC threads
47 // They were chosen by running GCOld and SPECjbb on debris with different
48 // numbers of GC threads and choosing them based on the results
49
50 // all the same
51 static double rs_length_diff_defaults[] = {
52 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
53 };
54
55 static double cost_per_card_ms_defaults[] = {
56 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015
57 };
58
59 // all the same
60 static double young_cards_per_entry_ratio_defaults[] = {
61 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
62 };
63
64 static double cost_per_entry_ms_defaults[] = {
65 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005
66 };
67
68 static double cost_per_byte_ms_defaults[] = {
69 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009
70 };
71
72 // these should be pretty consistent
73 static double constant_other_time_ms_defaults[] = {
74 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0
75 };
76
77
78 static double young_other_cost_per_region_ms_defaults[] = {
79 0.3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1
80 };
81
82 static double non_young_other_cost_per_region_ms_defaults[] = {
83 1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30
84 };
85
86 G1CollectorPolicy::G1CollectorPolicy() :
87 _parallel_gc_threads(ParallelGCThreads),
88
89 _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
90 _stop_world_start(0.0),
91
92 _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
93 _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
94
95 _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
96 _prev_collection_pause_end_ms(0.0),
97 _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
98 _cost_per_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
99 _young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
100 _mixed_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
101 _cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
102 _mixed_cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
103 _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
104 _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
105 _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
106 _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
107 _non_young_other_cost_per_region_ms_seq(
108 new TruncatedSeq(TruncatedSeqLength)),
109
110 _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
111 _rs_lengths_seq(new TruncatedSeq(TruncatedSeqLength)),
112
113 _pause_time_target_ms((double) MaxGCPauseMillis),
114
115 _recent_prev_end_times_for_all_gcs_sec(
116 new TruncatedSeq(NumPrevPausesForHeuristics)),
117
118 _recent_avg_pause_time_ratio(0.0),
119
120 _eden_used_bytes_before_gc(0),
121 _survivor_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 uintx confidence_perc = G1ConfidencePercent;
154 // Put an artificial ceiling on this so that it's not set to a silly value.
155 if (confidence_perc > 100) {
156 confidence_perc = 100;
157 warning("G1ConfidencePercent is set to a value that is too large, "
158 "it's been updated to %u", confidence_perc);
159 }
160 // '_sigma' must be initialized before the SurvRateGroups below because they
161 // indirecty access '_sigma' trough the 'this' pointer in their constructor.
162 _sigma = (double) confidence_perc / 100.0;
163
164 _short_lived_surv_rate_group =
165 new SurvRateGroup(this, "Short Lived", G1YoungSurvRateNumRegionsSummary);
166 _survivor_surv_rate_group =
167 new SurvRateGroup(this, "Survivor", G1YoungSurvRateNumRegionsSummary);
168
169 // Set up the region size and associated fields. Given that the
170 // policy is created before the heap, we have to set this up here,
171 // so it's done as soon as possible.
172
173 // It would have been natural to pass initial_heap_byte_size() and
174 // max_heap_byte_size() to setup_heap_region_size() but those have
175 // not been set up at this point since they should be aligned with
176 // the region size. So, there is a circular dependency here. We base
177 // the region size on the heap size, but the heap size should be
178 // aligned with the region size. To get around this we use the
179 // unaligned values for the heap.
180 HeapRegion::setup_heap_region_size(InitialHeapSize, MaxHeapSize);
181 HeapRegionRemSet::setup_remset_size();
182
183 G1ErgoVerbose::initialize();
184 if (PrintAdaptiveSizePolicy) {
185 // Currently, we only use a single switch for all the heuristics.
186 G1ErgoVerbose::set_enabled(true);
187 // Given that we don't currently have a verboseness level
188 // parameter, we'll hardcode this to high. This can be easily
189 // changed in the future.
190 G1ErgoVerbose::set_level(ErgoHigh);
191 } else {
192 G1ErgoVerbose::set_enabled(false);
193 }
194
195 // Verify PLAB sizes
196 const size_t region_size = HeapRegion::GrainWords;
197 if (YoungPLABSize > region_size || OldPLABSize > region_size) {
198 char buffer[128];
199 jio_snprintf(buffer, sizeof(buffer), "%sPLABSize should be at most "SIZE_FORMAT,
200 OldPLABSize > region_size ? "Old" : "Young", region_size);
201 vm_exit_during_initialization(buffer);
202 }
203
204 _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime());
205 _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0;
206
207 _phase_times = new G1GCPhaseTimes(_parallel_gc_threads);
208
209 int index = MIN2(_parallel_gc_threads - 1, 7);
210
211 _rs_length_diff_seq->add(rs_length_diff_defaults[index]);
212 _cost_per_card_ms_seq->add(cost_per_card_ms_defaults[index]);
213 _young_cards_per_entry_ratio_seq->add(
214 young_cards_per_entry_ratio_defaults[index]);
215 _cost_per_entry_ms_seq->add(cost_per_entry_ms_defaults[index]);
216 _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]);
217 _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]);
218 _young_other_cost_per_region_ms_seq->add(
219 young_other_cost_per_region_ms_defaults[index]);
220 _non_young_other_cost_per_region_ms_seq->add(
221 non_young_other_cost_per_region_ms_defaults[index]);
222
223 // Below, we might need to calculate the pause time target based on
224 // the pause interval. When we do so we are going to give G1 maximum
225 // flexibility and allow it to do pauses when it needs to. So, we'll
226 // arrange that the pause interval to be pause time target + 1 to
227 // ensure that a) the pause time target is maximized with respect to
228 // the pause interval and b) we maintain the invariant that pause
229 // time target < pause interval. If the user does not want this
230 // maximum flexibility, they will have to set the pause interval
231 // explicitly.
232
233 // First make sure that, if either parameter is set, its value is
234 // reasonable.
235 if (!FLAG_IS_DEFAULT(MaxGCPauseMillis)) {
236 if (MaxGCPauseMillis < 1) {
237 vm_exit_during_initialization("MaxGCPauseMillis should be "
238 "greater than 0");
239 }
240 }
241 if (!FLAG_IS_DEFAULT(GCPauseIntervalMillis)) {
242 if (GCPauseIntervalMillis < 1) {
243 vm_exit_during_initialization("GCPauseIntervalMillis should be "
244 "greater than 0");
245 }
246 }
247
248 // Then, if the pause time target parameter was not set, set it to
249 // the default value.
250 if (FLAG_IS_DEFAULT(MaxGCPauseMillis)) {
251 if (FLAG_IS_DEFAULT(GCPauseIntervalMillis)) {
252 // The default pause time target in G1 is 200ms
253 FLAG_SET_DEFAULT(MaxGCPauseMillis, 200);
254 } else {
255 // We do not allow the pause interval to be set without the
256 // pause time target
257 vm_exit_during_initialization("GCPauseIntervalMillis cannot be set "
258 "without setting MaxGCPauseMillis");
259 }
260 }
261
262 // Then, if the interval parameter was not set, set it according to
263 // the pause time target (this will also deal with the case when the
264 // pause time target is the default value).
265 if (FLAG_IS_DEFAULT(GCPauseIntervalMillis)) {
266 FLAG_SET_DEFAULT(GCPauseIntervalMillis, MaxGCPauseMillis + 1);
267 }
268
269 // Finally, make sure that the two parameters are consistent.
270 if (MaxGCPauseMillis >= GCPauseIntervalMillis) {
271 char buffer[256];
272 jio_snprintf(buffer, 256,
273 "MaxGCPauseMillis (%u) should be less than "
274 "GCPauseIntervalMillis (%u)",
275 MaxGCPauseMillis, GCPauseIntervalMillis);
276 vm_exit_during_initialization(buffer);
277 }
278
279 double max_gc_time = (double) MaxGCPauseMillis / 1000.0;
280 double time_slice = (double) GCPauseIntervalMillis / 1000.0;
281 _mmu_tracker = new G1MMUTrackerQueue(time_slice, max_gc_time);
282
283 // start conservatively (around 50ms is about right)
284 _concurrent_mark_remark_times_ms->add(0.05);
285 _concurrent_mark_cleanup_times_ms->add(0.20);
286 _tenuring_threshold = MaxTenuringThreshold;
287 // _max_survivor_regions will be calculated by
288 // update_young_list_target_length() during initialization.
289 _max_survivor_regions = 0;
290
291 assert(GCTimeRatio > 0,
292 "we should have set it to a default value set_g1_gc_flags() "
293 "if a user set it to 0");
294 _gc_overhead_perc = 100.0 * (1.0 / (1.0 + GCTimeRatio));
295
296 uintx reserve_perc = G1ReservePercent;
297 // Put an artificial ceiling on this so that it's not set to a silly value.
298 if (reserve_perc > 50) {
299 reserve_perc = 50;
300 warning("G1ReservePercent is set to a value that is too large, "
301 "it's been updated to %u", reserve_perc);
302 }
303 _reserve_factor = (double) reserve_perc / 100.0;
304 // This will be set when the heap is expanded
305 // for the first time during initialization.
306 _reserve_regions = 0;
307
308 _collectionSetChooser = new CollectionSetChooser();
309 }
310
311 void G1CollectorPolicy::initialize_alignments() {
312 _space_alignment = HeapRegion::GrainBytes;
313 size_t card_table_alignment = GenRemSet::max_alignment_constraint();
314 size_t page_size = UseLargePages ? os::large_page_size() : os::vm_page_size();
315 _heap_alignment = MAX3(card_table_alignment, _space_alignment, page_size);
316 }
317
318 void G1CollectorPolicy::initialize_flags() {
319 if (G1HeapRegionSize != HeapRegion::GrainBytes) {
320 FLAG_SET_ERGO(uintx, G1HeapRegionSize, HeapRegion::GrainBytes);
321 }
322
323 if (SurvivorRatio < 1) {
324 vm_exit_during_initialization("Invalid survivor ratio specified");
325 }
326 CollectorPolicy::initialize_flags();
327 _young_gen_sizer = new G1YoungGenSizer(); // Must be after call to initialize_flags
328 }
329
330 void G1CollectorPolicy::post_heap_initialize() {
331 uintx max_regions = G1CollectedHeap::heap()->max_regions();
332 size_t max_young_size = (size_t)_young_gen_sizer->max_young_length(max_regions) * HeapRegion::GrainBytes;
333 if (max_young_size != MaxNewSize) {
334 FLAG_SET_ERGO(uintx, MaxNewSize, max_young_size);
335 }
336 }
337
338 G1YoungGenSizer::G1YoungGenSizer() : _sizer_kind(SizerDefaults), _adaptive_size(true),
339 _min_desired_young_length(0), _max_desired_young_length(0) {
340 if (FLAG_IS_CMDLINE(NewRatio)) {
341 if (FLAG_IS_CMDLINE(NewSize) || FLAG_IS_CMDLINE(MaxNewSize)) {
342 warning("-XX:NewSize and -XX:MaxNewSize override -XX:NewRatio");
343 } else {
344 _sizer_kind = SizerNewRatio;
345 _adaptive_size = false;
346 return;
347 }
348 }
349
350 if (NewSize > MaxNewSize) {
351 if (FLAG_IS_CMDLINE(MaxNewSize)) {
352 warning("NewSize (" SIZE_FORMAT "k) is greater than the MaxNewSize (" SIZE_FORMAT "k). "
353 "A new max generation size of " SIZE_FORMAT "k will be used.",
354 NewSize/K, MaxNewSize/K, NewSize/K);
355 }
356 MaxNewSize = NewSize;
357 }
358
359 if (FLAG_IS_CMDLINE(NewSize)) {
360 _min_desired_young_length = MAX2((uint) (NewSize / HeapRegion::GrainBytes),
361 1U);
362 if (FLAG_IS_CMDLINE(MaxNewSize)) {
363 _max_desired_young_length =
364 MAX2((uint) (MaxNewSize / HeapRegion::GrainBytes),
365 1U);
366 _sizer_kind = SizerMaxAndNewSize;
367 _adaptive_size = _min_desired_young_length == _max_desired_young_length;
368 } else {
369 _sizer_kind = SizerNewSizeOnly;
370 }
371 } else if (FLAG_IS_CMDLINE(MaxNewSize)) {
372 _max_desired_young_length =
373 MAX2((uint) (MaxNewSize / HeapRegion::GrainBytes),
374 1U);
375 _sizer_kind = SizerMaxNewSizeOnly;
376 }
377 }
378
379 uint G1YoungGenSizer::calculate_default_min_length(uint new_number_of_heap_regions) {
380 uint default_value = (new_number_of_heap_regions * G1NewSizePercent) / 100;
381 return MAX2(1U, default_value);
382 }
383
384 uint G1YoungGenSizer::calculate_default_max_length(uint new_number_of_heap_regions) {
385 uint default_value = (new_number_of_heap_regions * G1MaxNewSizePercent) / 100;
386 return MAX2(1U, default_value);
387 }
388
389 void G1YoungGenSizer::recalculate_min_max_young_length(uint number_of_heap_regions, uint* min_young_length, uint* max_young_length) {
390 assert(number_of_heap_regions > 0, "Heap must be initialized");
391
392 switch (_sizer_kind) {
393 case SizerDefaults:
394 *min_young_length = calculate_default_min_length(number_of_heap_regions);
395 *max_young_length = calculate_default_max_length(number_of_heap_regions);
396 break;
397 case SizerNewSizeOnly:
398 *max_young_length = calculate_default_max_length(number_of_heap_regions);
399 *max_young_length = MAX2(*min_young_length, *max_young_length);
400 break;
401 case SizerMaxNewSizeOnly:
402 *min_young_length = calculate_default_min_length(number_of_heap_regions);
403 *min_young_length = MIN2(*min_young_length, *max_young_length);
404 break;
405 case SizerMaxAndNewSize:
406 // Do nothing. Values set on the command line, don't update them at runtime.
407 break;
408 case SizerNewRatio:
409 *min_young_length = number_of_heap_regions / (NewRatio + 1);
410 *max_young_length = *min_young_length;
411 break;
412 default:
413 ShouldNotReachHere();
414 }
415
416 assert(*min_young_length <= *max_young_length, "Invalid min/max young gen size values");
417 }
418
419 uint G1YoungGenSizer::max_young_length(uint number_of_heap_regions) {
420 // We need to pass the desired values because recalculation may not update these
421 // values in some cases.
422 uint temp = _min_desired_young_length;
423 uint result = _max_desired_young_length;
424 recalculate_min_max_young_length(number_of_heap_regions, &temp, &result);
425 return result;
426 }
427
428 void G1YoungGenSizer::heap_size_changed(uint new_number_of_heap_regions) {
429 recalculate_min_max_young_length(new_number_of_heap_regions, &_min_desired_young_length,
430 &_max_desired_young_length);
431 }
432
433 void G1CollectorPolicy::init() {
434 // Set aside an initial future to_space.
435 _g1 = G1CollectedHeap::heap();
436
437 assert(Heap_lock->owned_by_self(), "Locking discipline.");
438
439 initialize_gc_policy_counters();
440
441 if (adaptive_young_list_length()) {
442 _young_list_fixed_length = 0;
443 } else {
444 _young_list_fixed_length = _young_gen_sizer->min_desired_young_length();
445 }
446 _free_regions_at_end_of_collection = _g1->num_free_regions();
447 update_young_list_target_length();
448
449 // We may immediately start allocating regions and placing them on the
450 // collection set list. Initialize the per-collection set info
451 start_incremental_cset_building();
452 }
453
454 // Create the jstat counters for the policy.
455 void G1CollectorPolicy::initialize_gc_policy_counters() {
456 _gc_policy_counters = new GCPolicyCounters("GarbageFirst", 1, 3);
457 }
458
459 bool G1CollectorPolicy::predict_will_fit(uint young_length,
460 double base_time_ms,
461 uint base_free_regions,
462 double target_pause_time_ms) {
463 if (young_length >= base_free_regions) {
464 // end condition 1: not enough space for the young regions
465 return false;
466 }
467
468 double accum_surv_rate = accum_yg_surv_rate_pred((int) young_length - 1);
469 size_t bytes_to_copy =
470 (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
471 double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
472 double young_other_time_ms = predict_young_other_time_ms(young_length);
473 double pause_time_ms = base_time_ms + copy_time_ms + young_other_time_ms;
474 if (pause_time_ms > target_pause_time_ms) {
475 // end condition 2: prediction is over the target pause time
476 return false;
477 }
478
479 size_t free_bytes =
480 (base_free_regions - young_length) * HeapRegion::GrainBytes;
481 if ((2.0 * sigma()) * (double) bytes_to_copy > (double) free_bytes) {
482 // end condition 3: out-of-space (conservatively!)
483 return false;
484 }
485
486 // success!
487 return true;
488 }
489
490 void G1CollectorPolicy::record_new_heap_size(uint new_number_of_regions) {
491 // re-calculate the necessary reserve
492 double reserve_regions_d = (double) new_number_of_regions * _reserve_factor;
493 // We use ceiling so that if reserve_regions_d is > 0.0 (but
494 // smaller than 1.0) we'll get 1.
495 _reserve_regions = (uint) ceil(reserve_regions_d);
496
497 _young_gen_sizer->heap_size_changed(new_number_of_regions);
498 }
499
500 uint G1CollectorPolicy::calculate_young_list_desired_min_length(
501 uint base_min_length) {
502 uint desired_min_length = 0;
503 if (adaptive_young_list_length()) {
504 if (_alloc_rate_ms_seq->num() > 3) {
505 double now_sec = os::elapsedTime();
506 double when_ms = _mmu_tracker->when_max_gc_sec(now_sec) * 1000.0;
507 double alloc_rate_ms = predict_alloc_rate_ms();
508 desired_min_length = (uint) ceil(alloc_rate_ms * when_ms);
509 } else {
510 // otherwise we don't have enough info to make the prediction
511 }
512 }
513 desired_min_length += base_min_length;
514 // make sure we don't go below any user-defined minimum bound
515 return MAX2(_young_gen_sizer->min_desired_young_length(), desired_min_length);
516 }
517
518 uint G1CollectorPolicy::calculate_young_list_desired_max_length() {
519 // Here, we might want to also take into account any additional
520 // constraints (i.e., user-defined minimum bound). Currently, we
521 // effectively don't set this bound.
522 return _young_gen_sizer->max_desired_young_length();
523 }
524
525 void G1CollectorPolicy::update_young_list_target_length(size_t rs_lengths) {
526 if (rs_lengths == (size_t) -1) {
527 // if it's set to the default value (-1), we should predict it;
528 // otherwise, use the given value.
529 rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
530 }
531
532 // Calculate the absolute and desired min bounds.
533
534 // This is how many young regions we already have (currently: the survivors).
535 uint base_min_length = recorded_survivor_regions();
536 // This is the absolute minimum young length, which ensures that we
537 // can allocate one eden region in the worst-case.
538 uint absolute_min_length = base_min_length + 1;
539 uint desired_min_length =
540 calculate_young_list_desired_min_length(base_min_length);
541 if (desired_min_length < absolute_min_length) {
542 desired_min_length = absolute_min_length;
543 }
544
545 // Calculate the absolute and desired max bounds.
546
547 // We will try our best not to "eat" into the reserve.
548 uint absolute_max_length = 0;
549 if (_free_regions_at_end_of_collection > _reserve_regions) {
550 absolute_max_length = _free_regions_at_end_of_collection - _reserve_regions;
551 }
552 uint desired_max_length = calculate_young_list_desired_max_length();
553 if (desired_max_length > absolute_max_length) {
554 desired_max_length = absolute_max_length;
555 }
556
557 uint young_list_target_length = 0;
558 if (adaptive_young_list_length()) {
559 if (collector_state()->gcs_are_young()) {
560 young_list_target_length =
561 calculate_young_list_target_length(rs_lengths,
562 base_min_length,
563 desired_min_length,
564 desired_max_length);
565 _rs_lengths_prediction = rs_lengths;
566 } else {
567 // Don't calculate anything and let the code below bound it to
568 // the desired_min_length, i.e., do the next GC as soon as
569 // possible to maximize how many old regions we can add to it.
570 }
571 } else {
572 // The user asked for a fixed young gen so we'll fix the young gen
573 // whether the next GC is young or mixed.
574 young_list_target_length = _young_list_fixed_length;
575 }
576
577 // Make sure we don't go over the desired max length, nor under the
578 // desired min length. In case they clash, desired_min_length wins
579 // which is why that test is second.
580 if (young_list_target_length > desired_max_length) {
581 young_list_target_length = desired_max_length;
582 }
583 if (young_list_target_length < desired_min_length) {
584 young_list_target_length = desired_min_length;
585 }
586
587 assert(young_list_target_length > recorded_survivor_regions(),
588 "we should be able to allocate at least one eden region");
589 assert(young_list_target_length >= absolute_min_length, "post-condition");
590 _young_list_target_length = young_list_target_length;
591
592 update_max_gc_locker_expansion();
593 }
594
595 uint
596 G1CollectorPolicy::calculate_young_list_target_length(size_t rs_lengths,
597 uint base_min_length,
598 uint desired_min_length,
599 uint desired_max_length) {
600 assert(adaptive_young_list_length(), "pre-condition");
601 assert(collector_state()->gcs_are_young(), "only call this for young GCs");
602
603 // In case some edge-condition makes the desired max length too small...
604 if (desired_max_length <= desired_min_length) {
605 return desired_min_length;
606 }
607
608 // We'll adjust min_young_length and max_young_length not to include
609 // the already allocated young regions (i.e., so they reflect the
610 // min and max eden regions we'll allocate). The base_min_length
611 // will be reflected in the predictions by the
612 // survivor_regions_evac_time prediction.
613 assert(desired_min_length > base_min_length, "invariant");
614 uint min_young_length = desired_min_length - base_min_length;
615 assert(desired_max_length > base_min_length, "invariant");
616 uint max_young_length = desired_max_length - base_min_length;
617
618 double target_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
619 double survivor_regions_evac_time = predict_survivor_regions_evac_time();
620 size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
621 size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
622 size_t scanned_cards = predict_young_card_num(adj_rs_lengths);
623 double base_time_ms =
624 predict_base_elapsed_time_ms(pending_cards, scanned_cards) +
625 survivor_regions_evac_time;
626 uint available_free_regions = _free_regions_at_end_of_collection;
627 uint base_free_regions = 0;
628 if (available_free_regions > _reserve_regions) {
629 base_free_regions = available_free_regions - _reserve_regions;
630 }
631
632 // Here, we will make sure that the shortest young length that
633 // makes sense fits within the target pause time.
634
635 if (predict_will_fit(min_young_length, base_time_ms,
636 base_free_regions, target_pause_time_ms)) {
637 // The shortest young length will fit into the target pause time;
638 // we'll now check whether the absolute maximum number of young
639 // regions will fit in the target pause time. If not, we'll do
640 // a binary search between min_young_length and max_young_length.
641 if (predict_will_fit(max_young_length, base_time_ms,
642 base_free_regions, target_pause_time_ms)) {
643 // The maximum young length will fit into the target pause time.
644 // We are done so set min young length to the maximum length (as
645 // the result is assumed to be returned in min_young_length).
646 min_young_length = max_young_length;
647 } else {
648 // The maximum possible number of young regions will not fit within
649 // the target pause time so we'll search for the optimal
650 // length. The loop invariants are:
651 //
652 // min_young_length < max_young_length
653 // min_young_length is known to fit into the target pause time
654 // max_young_length is known not to fit into the target pause time
655 //
656 // Going into the loop we know the above hold as we've just
657 // checked them. Every time around the loop we check whether
658 // the middle value between min_young_length and
659 // max_young_length fits into the target pause time. If it
660 // does, it becomes the new min. If it doesn't, it becomes
661 // the new max. This way we maintain the loop invariants.
662
663 assert(min_young_length < max_young_length, "invariant");
664 uint diff = (max_young_length - min_young_length) / 2;
665 while (diff > 0) {
666 uint young_length = min_young_length + diff;
667 if (predict_will_fit(young_length, base_time_ms,
668 base_free_regions, target_pause_time_ms)) {
669 min_young_length = young_length;
670 } else {
671 max_young_length = young_length;
672 }
673 assert(min_young_length < max_young_length, "invariant");
674 diff = (max_young_length - min_young_length) / 2;
675 }
676 // The results is min_young_length which, according to the
677 // loop invariants, should fit within the target pause time.
678
679 // These are the post-conditions of the binary search above:
680 assert(min_young_length < max_young_length,
681 "otherwise we should have discovered that max_young_length "
682 "fits into the pause target and not done the binary search");
683 assert(predict_will_fit(min_young_length, base_time_ms,
684 base_free_regions, target_pause_time_ms),
685 "min_young_length, the result of the binary search, should "
686 "fit into the pause target");
687 assert(!predict_will_fit(min_young_length + 1, base_time_ms,
688 base_free_regions, target_pause_time_ms),
689 "min_young_length, the result of the binary search, should be "
690 "optimal, so no larger length should fit into the pause target");
691 }
692 } else {
693 // Even the minimum length doesn't fit into the pause time
694 // target, return it as the result nevertheless.
695 }
696 return base_min_length + min_young_length;
697 }
698
699 double G1CollectorPolicy::predict_survivor_regions_evac_time() {
700 double survivor_regions_evac_time = 0.0;
701 for (HeapRegion * r = _recorded_survivor_head;
702 r != NULL && r != _recorded_survivor_tail->get_next_young_region();
703 r = r->get_next_young_region()) {
704 survivor_regions_evac_time += predict_region_elapsed_time_ms(r, collector_state()->gcs_are_young());
705 }
706 return survivor_regions_evac_time;
707 }
708
709 void G1CollectorPolicy::revise_young_list_target_length_if_necessary() {
710 guarantee( adaptive_young_list_length(), "should not call this otherwise" );
711
712 size_t rs_lengths = _g1->young_list()->sampled_rs_lengths();
713 if (rs_lengths > _rs_lengths_prediction) {
714 // add 10% to avoid having to recalculate often
715 size_t rs_lengths_prediction = rs_lengths * 1100 / 1000;
716 update_young_list_target_length(rs_lengths_prediction);
717 }
718 }
719
720
721
722 HeapWord* G1CollectorPolicy::mem_allocate_work(size_t size,
723 bool is_tlab,
724 bool* gc_overhead_limit_was_exceeded) {
725 guarantee(false, "Not using this policy feature yet.");
726 return NULL;
727 }
728
729 // This method controls how a collector handles one or more
730 // of its generations being fully allocated.
731 HeapWord* G1CollectorPolicy::satisfy_failed_allocation(size_t size,
732 bool is_tlab) {
733 guarantee(false, "Not using this policy feature yet.");
734 return NULL;
735 }
736
737
738 #ifndef PRODUCT
739 bool G1CollectorPolicy::verify_young_ages() {
740 HeapRegion* head = _g1->young_list()->first_region();
741 return
742 verify_young_ages(head, _short_lived_surv_rate_group);
743 // also call verify_young_ages on any additional surv rate groups
744 }
745
746 bool
747 G1CollectorPolicy::verify_young_ages(HeapRegion* head,
748 SurvRateGroup *surv_rate_group) {
749 guarantee( surv_rate_group != NULL, "pre-condition" );
750
751 const char* name = surv_rate_group->name();
752 bool ret = true;
753 int prev_age = -1;
754
755 for (HeapRegion* curr = head;
756 curr != NULL;
757 curr = curr->get_next_young_region()) {
758 SurvRateGroup* group = curr->surv_rate_group();
759 if (group == NULL && !curr->is_survivor()) {
760 gclog_or_tty->print_cr("## %s: encountered NULL surv_rate_group", name);
761 ret = false;
762 }
763
764 if (surv_rate_group == group) {
765 int age = curr->age_in_surv_rate_group();
766
767 if (age < 0) {
768 gclog_or_tty->print_cr("## %s: encountered negative age", name);
769 ret = false;
770 }
771
772 if (age <= prev_age) {
773 gclog_or_tty->print_cr("## %s: region ages are not strictly increasing "
774 "(%d, %d)", name, age, prev_age);
775 ret = false;
776 }
777 prev_age = age;
778 }
779 }
780
781 return ret;
782 }
783 #endif // PRODUCT
784
785 void G1CollectorPolicy::record_full_collection_start() {
786 _full_collection_start_sec = os::elapsedTime();
787 record_heap_size_info_at_start(true /* full */);
788 // Release the future to-space so that it is available for compaction into.
789 _g1->set_full_collection();
790 }
791
792 void G1CollectorPolicy::record_full_collection_end() {
793 // Consider this like a collection pause for the purposes of allocation
794 // since last pause.
795 double end_sec = os::elapsedTime();
796 double full_gc_time_sec = end_sec - _full_collection_start_sec;
797 double full_gc_time_ms = full_gc_time_sec * 1000.0;
798
799 _trace_old_gen_time_data.record_full_collection(full_gc_time_ms);
800
801 update_recent_gc_times(end_sec, full_gc_time_ms);
802
803 _g1->clear_full_collection();
804
805 // "Nuke" the heuristics that control the young/mixed GC
806 // transitions and make sure we start with young GCs after the Full GC.
807 collector_state()->set_gcs_are_young(true);
808 collector_state()->set_last_young_gc(false);
809 collector_state()->set_initiate_conc_mark_if_possible(false);
810 collector_state()->set_during_initial_mark_pause(false);
811 collector_state()->set_in_marking_window(false);
812 collector_state()->set_in_marking_window_im(false);
813
814 _short_lived_surv_rate_group->start_adding_regions();
815 // also call this on any additional surv rate groups
816
817 record_survivor_regions(0, NULL, NULL);
818
819 _free_regions_at_end_of_collection = _g1->num_free_regions();
820 // Reset survivors SurvRateGroup.
821 _survivor_surv_rate_group->reset();
822 update_young_list_target_length();
823 _collectionSetChooser->clear();
824 }
825
826 void G1CollectorPolicy::record_stop_world_start() {
827 _stop_world_start = os::elapsedTime();
828 }
829
830 void G1CollectorPolicy::record_collection_pause_start(double start_time_sec) {
831 // We only need to do this here as the policy will only be applied
832 // to the GC we're about to start. so, no point is calculating this
833 // every time we calculate / recalculate the target young length.
834 update_survivors_policy();
835
836 assert(_g1->used() == _g1->recalculate_used(),
837 err_msg("sanity, used: "SIZE_FORMAT" recalculate_used: "SIZE_FORMAT,
838 _g1->used(), _g1->recalculate_used()));
839
840 double s_w_t_ms = (start_time_sec - _stop_world_start) * 1000.0;
841 _trace_young_gen_time_data.record_start_collection(s_w_t_ms);
842 _stop_world_start = 0.0;
843
844 record_heap_size_info_at_start(false /* full */);
845
846 phase_times()->record_cur_collection_start_sec(start_time_sec);
847 _pending_cards = _g1->pending_card_num();
848
849 _collection_set_bytes_used_before = 0;
850 _bytes_copied_during_gc = 0;
851
852 collector_state()->set_last_gc_was_young(false);
853
854 // do that for any other surv rate groups
855 _short_lived_surv_rate_group->stop_adding_regions();
856 _survivors_age_table.clear();
857
858 assert( verify_young_ages(), "region age verification" );
859 }
860
861 void G1CollectorPolicy::record_concurrent_mark_init_end(double
862 mark_init_elapsed_time_ms) {
863 collector_state()->set_during_marking(true);
864 assert(!collector_state()->initiate_conc_mark_if_possible(), "we should have cleared it by now");
865 collector_state()->set_during_initial_mark_pause(false);
866 _cur_mark_stop_world_time_ms = mark_init_elapsed_time_ms;
867 }
868
869 void G1CollectorPolicy::record_concurrent_mark_remark_start() {
870 _mark_remark_start_sec = os::elapsedTime();
871 collector_state()->set_during_marking(false);
872 }
873
874 void G1CollectorPolicy::record_concurrent_mark_remark_end() {
875 double end_time_sec = os::elapsedTime();
876 double elapsed_time_ms = (end_time_sec - _mark_remark_start_sec)*1000.0;
877 _concurrent_mark_remark_times_ms->add(elapsed_time_ms);
878 _cur_mark_stop_world_time_ms += elapsed_time_ms;
879 _prev_collection_pause_end_ms += elapsed_time_ms;
880
881 _mmu_tracker->add_pause(_mark_remark_start_sec, end_time_sec, true);
882 }
883
884 void G1CollectorPolicy::record_concurrent_mark_cleanup_start() {
885 _mark_cleanup_start_sec = os::elapsedTime();
886 }
887
888 void G1CollectorPolicy::record_concurrent_mark_cleanup_completed() {
889 collector_state()->set_last_young_gc(true);
890 collector_state()->set_in_marking_window(false);
891 }
892
893 void G1CollectorPolicy::record_concurrent_pause() {
894 if (_stop_world_start > 0.0) {
895 double yield_ms = (os::elapsedTime() - _stop_world_start) * 1000.0;
896 _trace_young_gen_time_data.record_yield_time(yield_ms);
897 }
898 }
899
900 bool G1CollectorPolicy::need_to_start_conc_mark(const char* source, size_t alloc_word_size) {
901 if (_g1->concurrent_mark()->cmThread()->during_cycle()) {
902 return false;
903 }
904
905 size_t marking_initiating_used_threshold =
906 (_g1->capacity() / 100) * InitiatingHeapOccupancyPercent;
907 size_t cur_used_bytes = _g1->non_young_capacity_bytes();
908 size_t alloc_byte_size = alloc_word_size * HeapWordSize;
909
910 if ((cur_used_bytes + alloc_byte_size) > marking_initiating_used_threshold) {
911 if (collector_state()->gcs_are_young() && !collector_state()->last_young_gc()) {
912 ergo_verbose5(ErgoConcCycles,
913 "request concurrent cycle initiation",
914 ergo_format_reason("occupancy higher than threshold")
915 ergo_format_byte("occupancy")
916 ergo_format_byte("allocation request")
917 ergo_format_byte_perc("threshold")
918 ergo_format_str("source"),
919 cur_used_bytes,
920 alloc_byte_size,
921 marking_initiating_used_threshold,
922 (double) InitiatingHeapOccupancyPercent,
923 source);
924 return true;
925 } else {
926 ergo_verbose5(ErgoConcCycles,
927 "do not request concurrent cycle initiation",
928 ergo_format_reason("still doing mixed collections")
929 ergo_format_byte("occupancy")
930 ergo_format_byte("allocation request")
931 ergo_format_byte_perc("threshold")
932 ergo_format_str("source"),
933 cur_used_bytes,
934 alloc_byte_size,
935 marking_initiating_used_threshold,
936 (double) InitiatingHeapOccupancyPercent,
937 source);
938 }
939 }
940
941 return false;
942 }
943
944 // Anything below that is considered to be zero
945 #define MIN_TIMER_GRANULARITY 0.0000001
946
947 void G1CollectorPolicy::record_collection_pause_end(double pause_time_ms, EvacuationInfo& evacuation_info) {
948 double end_time_sec = os::elapsedTime();
949 assert(_cur_collection_pause_used_regions_at_start >= cset_region_length(),
950 "otherwise, the subtraction below does not make sense");
951 size_t rs_size =
952 _cur_collection_pause_used_regions_at_start - cset_region_length();
953 size_t cur_used_bytes = _g1->used();
954 assert(cur_used_bytes == _g1->recalculate_used(), "It should!");
955 bool last_pause_included_initial_mark = false;
956 bool update_stats = !_g1->evacuation_failed();
957
958 #ifndef PRODUCT
959 if (G1YoungSurvRateVerbose) {
960 gclog_or_tty->cr();
961 _short_lived_surv_rate_group->print();
962 // do that for any other surv rate groups too
963 }
964 #endif // PRODUCT
965
966 last_pause_included_initial_mark = collector_state()->during_initial_mark_pause();
967 if (last_pause_included_initial_mark) {
968 record_concurrent_mark_init_end(0.0);
969 } else if (need_to_start_conc_mark("end of GC")) {
970 // Note: this might have already been set, if during the last
971 // pause we decided to start a cycle but at the beginning of
972 // this pause we decided to postpone it. That's OK.
973 collector_state()->set_initiate_conc_mark_if_possible(true);
974 }
975
976 _mmu_tracker->add_pause(end_time_sec - pause_time_ms/1000.0,
977 end_time_sec, false);
978
979 evacuation_info.set_collectionset_used_before(_collection_set_bytes_used_before);
980 evacuation_info.set_bytes_copied(_bytes_copied_during_gc);
981
982 if (update_stats) {
983 _trace_young_gen_time_data.record_end_collection(pause_time_ms, phase_times());
984 // this is where we update the allocation rate of the application
985 double app_time_ms =
986 (phase_times()->cur_collection_start_sec() * 1000.0 - _prev_collection_pause_end_ms);
987 if (app_time_ms < MIN_TIMER_GRANULARITY) {
988 // This usually happens due to the timer not having the required
989 // granularity. Some Linuxes are the usual culprits.
990 // We'll just set it to something (arbitrarily) small.
991 app_time_ms = 1.0;
992 }
993 // We maintain the invariant that all objects allocated by mutator
994 // threads will be allocated out of eden regions. So, we can use
995 // the eden region number allocated since the previous GC to
996 // calculate the application's allocate rate. The only exception
997 // to that is humongous objects that are allocated separately. But
998 // given that humongous object allocations do not really affect
999 // either the pause's duration nor when the next pause will take
1000 // place we can safely ignore them here.
1001 uint regions_allocated = eden_cset_region_length();
1002 double alloc_rate_ms = (double) regions_allocated / app_time_ms;
1003 _alloc_rate_ms_seq->add(alloc_rate_ms);
1004
1005 double interval_ms =
1006 (end_time_sec - _recent_prev_end_times_for_all_gcs_sec->oldest()) * 1000.0;
1007 update_recent_gc_times(end_time_sec, pause_time_ms);
1008 _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum()/interval_ms;
1009 if (recent_avg_pause_time_ratio() < 0.0 ||
1010 (recent_avg_pause_time_ratio() - 1.0 > 0.0)) {
1011 #ifndef PRODUCT
1012 // Dump info to allow post-facto debugging
1013 gclog_or_tty->print_cr("recent_avg_pause_time_ratio() out of bounds");
1014 gclog_or_tty->print_cr("-------------------------------------------");
1015 gclog_or_tty->print_cr("Recent GC Times (ms):");
1016 _recent_gc_times_ms->dump();
1017 gclog_or_tty->print_cr("(End Time=%3.3f) Recent GC End Times (s):", end_time_sec);
1018 _recent_prev_end_times_for_all_gcs_sec->dump();
1019 gclog_or_tty->print_cr("GC = %3.3f, Interval = %3.3f, Ratio = %3.3f",
1020 _recent_gc_times_ms->sum(), interval_ms, recent_avg_pause_time_ratio());
1021 // In debug mode, terminate the JVM if the user wants to debug at this point.
1022 assert(!G1FailOnFPError, "Debugging data for CR 6898948 has been dumped above");
1023 #endif // !PRODUCT
1024 // Clip ratio between 0.0 and 1.0, and continue. This will be fixed in
1025 // CR 6902692 by redoing the manner in which the ratio is incrementally computed.
1026 if (_recent_avg_pause_time_ratio < 0.0) {
1027 _recent_avg_pause_time_ratio = 0.0;
1028 } else {
1029 assert(_recent_avg_pause_time_ratio - 1.0 > 0.0, "Ctl-point invariant");
1030 _recent_avg_pause_time_ratio = 1.0;
1031 }
1032 }
1033 }
1034
1035 bool new_in_marking_window = collector_state()->in_marking_window();
1036 bool new_in_marking_window_im = false;
1037 if (last_pause_included_initial_mark) {
1038 new_in_marking_window = true;
1039 new_in_marking_window_im = true;
1040 }
1041
1042 if (collector_state()->last_young_gc()) {
1043 // This is supposed to to be the "last young GC" before we start
1044 // doing mixed GCs. Here we decide whether to start mixed GCs or not.
1045
1046 if (!last_pause_included_initial_mark) {
1047 if (next_gc_should_be_mixed("start mixed GCs",
1048 "do not start mixed GCs")) {
1049 collector_state()->set_gcs_are_young(false);
1050 }
1051 } else {
1052 ergo_verbose0(ErgoMixedGCs,
1053 "do not start mixed GCs",
1054 ergo_format_reason("concurrent cycle is about to start"));
1055 }
1056 collector_state()->set_last_young_gc(false);
1057 }
1058
1059 if (!collector_state()->last_gc_was_young()) {
1060 // This is a mixed GC. Here we decide whether to continue doing
1061 // mixed GCs or not.
1062
1063 if (!next_gc_should_be_mixed("continue mixed GCs",
1064 "do not continue mixed GCs")) {
1065 collector_state()->set_gcs_are_young(true);
1066 }
1067 }
1068
1069 _short_lived_surv_rate_group->start_adding_regions();
1070 // Do that for any other surv rate groups
1071
1072 if (update_stats) {
1073 double cost_per_card_ms = 0.0;
1074 if (_pending_cards > 0) {
1075 cost_per_card_ms = phase_times()->average_last_update_rs_time() / (double) _pending_cards;
1076 _cost_per_card_ms_seq->add(cost_per_card_ms);
1077 }
1078
1079 size_t cards_scanned = _g1->cards_scanned();
1080
1081 double cost_per_entry_ms = 0.0;
1082 if (cards_scanned > 10) {
1083 cost_per_entry_ms = phase_times()->average_last_scan_rs_time() / (double) cards_scanned;
1084 if (collector_state()->last_gc_was_young()) {
1085 _cost_per_entry_ms_seq->add(cost_per_entry_ms);
1086 } else {
1087 _mixed_cost_per_entry_ms_seq->add(cost_per_entry_ms);
1088 }
1089 }
1090
1091 if (_max_rs_lengths > 0) {
1092 double cards_per_entry_ratio =
1093 (double) cards_scanned / (double) _max_rs_lengths;
1094 if (collector_state()->last_gc_was_young()) {
1095 _young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
1096 } else {
1097 _mixed_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
1098 }
1099 }
1100
1101 // This is defensive. For a while _max_rs_lengths could get
1102 // smaller than _recorded_rs_lengths which was causing
1103 // rs_length_diff to get very large and mess up the RSet length
1104 // predictions. The reason was unsafe concurrent updates to the
1105 // _inc_cset_recorded_rs_lengths field which the code below guards
1106 // against (see CR 7118202). This bug has now been fixed (see CR
1107 // 7119027). However, I'm still worried that
1108 // _inc_cset_recorded_rs_lengths might still end up somewhat
1109 // inaccurate. The concurrent refinement thread calculates an
1110 // RSet's length concurrently with other CR threads updating it
1111 // which might cause it to calculate the length incorrectly (if,
1112 // say, it's in mid-coarsening). So I'll leave in the defensive
1113 // conditional below just in case.
1114 size_t rs_length_diff = 0;
1115 if (_max_rs_lengths > _recorded_rs_lengths) {
1116 rs_length_diff = _max_rs_lengths - _recorded_rs_lengths;
1117 }
1118 _rs_length_diff_seq->add((double) rs_length_diff);
1119
1120 size_t freed_bytes = _heap_used_bytes_before_gc - cur_used_bytes;
1121 size_t copied_bytes = _collection_set_bytes_used_before - freed_bytes;
1122 double cost_per_byte_ms = 0.0;
1123
1124 if (copied_bytes > 0) {
1125 cost_per_byte_ms = phase_times()->average_last_obj_copy_time() / (double) copied_bytes;
1126 if (collector_state()->in_marking_window()) {
1127 _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms);
1128 } else {
1129 _cost_per_byte_ms_seq->add(cost_per_byte_ms);
1130 }
1131 }
1132
1133 double all_other_time_ms = pause_time_ms -
1134 (phase_times()->average_last_update_rs_time() + phase_times()->average_last_scan_rs_time()
1135 + phase_times()->average_last_obj_copy_time() + phase_times()->average_last_termination_time());
1136
1137 double young_other_time_ms = 0.0;
1138 if (young_cset_region_length() > 0) {
1139 young_other_time_ms =
1140 phase_times()->young_cset_choice_time_ms() +
1141 phase_times()->young_free_cset_time_ms();
1142 _young_other_cost_per_region_ms_seq->add(young_other_time_ms /
1143 (double) young_cset_region_length());
1144 }
1145 double non_young_other_time_ms = 0.0;
1146 if (old_cset_region_length() > 0) {
1147 non_young_other_time_ms =
1148 phase_times()->non_young_cset_choice_time_ms() +
1149 phase_times()->non_young_free_cset_time_ms();
1150
1151 _non_young_other_cost_per_region_ms_seq->add(non_young_other_time_ms /
1152 (double) old_cset_region_length());
1153 }
1154
1155 double constant_other_time_ms = all_other_time_ms -
1156 (young_other_time_ms + non_young_other_time_ms);
1157 _constant_other_time_ms_seq->add(constant_other_time_ms);
1158
1159 double survival_ratio = 0.0;
1160 if (_collection_set_bytes_used_before > 0) {
1161 survival_ratio = (double) _bytes_copied_during_gc /
1162 (double) _collection_set_bytes_used_before;
1163 }
1164
1165 _pending_cards_seq->add((double) _pending_cards);
1166 _rs_lengths_seq->add((double) _max_rs_lengths);
1167 }
1168
1169 collector_state()->set_in_marking_window(new_in_marking_window);
1170 collector_state()->set_in_marking_window_im(new_in_marking_window_im);
1171 _free_regions_at_end_of_collection = _g1->num_free_regions();
1172 update_young_list_target_length();
1173
1174 // Note that _mmu_tracker->max_gc_time() returns the time in seconds.
1175 double update_rs_time_goal_ms = _mmu_tracker->max_gc_time() * MILLIUNITS * G1RSetUpdatingPauseTimePercent / 100.0;
1176 adjust_concurrent_refinement(phase_times()->average_last_update_rs_time(),
1177 phase_times()->sum_last_update_rs_processed_buffers(), update_rs_time_goal_ms);
1178
1179 _collectionSetChooser->verify();
1180 }
1181
1182 #define EXT_SIZE_FORMAT "%.1f%s"
1183 #define EXT_SIZE_PARAMS(bytes) \
1184 byte_size_in_proper_unit((double)(bytes)), \
1185 proper_unit_for_byte_size((bytes))
1186
1187 void G1CollectorPolicy::record_heap_size_info_at_start(bool full) {
1188 YoungList* young_list = _g1->young_list();
1189 _eden_used_bytes_before_gc = young_list->eden_used_bytes();
1190 _survivor_used_bytes_before_gc = young_list->survivor_used_bytes();
1191 _heap_capacity_bytes_before_gc = _g1->capacity();
1192 _heap_used_bytes_before_gc = _g1->used();
1193 _cur_collection_pause_used_regions_at_start = _g1->num_used_regions();
1194
1195 _eden_capacity_bytes_before_gc =
1196 (_young_list_target_length * HeapRegion::GrainBytes) - _survivor_used_bytes_before_gc;
1197
1198 if (full) {
1199 _metaspace_used_bytes_before_gc = MetaspaceAux::used_bytes();
1200 }
1201 }
1202
1203 void G1CollectorPolicy::print_heap_transition() {
1204 _g1->print_size_transition(gclog_or_tty,
1205 _heap_used_bytes_before_gc,
1206 _g1->used(),
1207 _g1->capacity());
1208 }
1209
1210 void G1CollectorPolicy::print_detailed_heap_transition(bool full) {
1211 YoungList* young_list = _g1->young_list();
1212
1213 size_t eden_used_bytes_after_gc = young_list->eden_used_bytes();
1214 size_t survivor_used_bytes_after_gc = young_list->survivor_used_bytes();
1215 size_t heap_used_bytes_after_gc = _g1->used();
1216
1217 size_t heap_capacity_bytes_after_gc = _g1->capacity();
1218 size_t eden_capacity_bytes_after_gc =
1219 (_young_list_target_length * HeapRegion::GrainBytes) - survivor_used_bytes_after_gc;
1220
1221 gclog_or_tty->print(
1222 " [Eden: "EXT_SIZE_FORMAT"("EXT_SIZE_FORMAT")->"EXT_SIZE_FORMAT"("EXT_SIZE_FORMAT") "
1223 "Survivors: "EXT_SIZE_FORMAT"->"EXT_SIZE_FORMAT" "
1224 "Heap: "EXT_SIZE_FORMAT"("EXT_SIZE_FORMAT")->"
1225 EXT_SIZE_FORMAT"("EXT_SIZE_FORMAT")]",
1226 EXT_SIZE_PARAMS(_eden_used_bytes_before_gc),
1227 EXT_SIZE_PARAMS(_eden_capacity_bytes_before_gc),
1228 EXT_SIZE_PARAMS(eden_used_bytes_after_gc),
1229 EXT_SIZE_PARAMS(eden_capacity_bytes_after_gc),
1230 EXT_SIZE_PARAMS(_survivor_used_bytes_before_gc),
1231 EXT_SIZE_PARAMS(survivor_used_bytes_after_gc),
1232 EXT_SIZE_PARAMS(_heap_used_bytes_before_gc),
1233 EXT_SIZE_PARAMS(_heap_capacity_bytes_before_gc),
1234 EXT_SIZE_PARAMS(heap_used_bytes_after_gc),
1235 EXT_SIZE_PARAMS(heap_capacity_bytes_after_gc));
1236
1237 if (full) {
1238 MetaspaceAux::print_metaspace_change(_metaspace_used_bytes_before_gc);
1239 }
1240
1241 gclog_or_tty->cr();
1242 }
1243
1244 void G1CollectorPolicy::adjust_concurrent_refinement(double update_rs_time,
1245 double update_rs_processed_buffers,
1246 double goal_ms) {
1247 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
1248 ConcurrentG1Refine *cg1r = G1CollectedHeap::heap()->concurrent_g1_refine();
1249
1250 if (G1UseAdaptiveConcRefinement) {
1251 const int k_gy = 3, k_gr = 6;
1252 const double inc_k = 1.1, dec_k = 0.9;
1253
1254 int g = cg1r->green_zone();
1255 if (update_rs_time > goal_ms) {
1256 g = (int)(g * dec_k); // Can become 0, that's OK. That would mean a mutator-only processing.
1257 } else {
1258 if (update_rs_time < goal_ms && update_rs_processed_buffers > g) {
1259 g = (int)MAX2(g * inc_k, g + 1.0);
1260 }
1261 }
1262 // Change the refinement threads params
1263 cg1r->set_green_zone(g);
1264 cg1r->set_yellow_zone(g * k_gy);
1265 cg1r->set_red_zone(g * k_gr);
1266 cg1r->reinitialize_threads();
1267
1268 int processing_threshold_delta = MAX2((int)(cg1r->green_zone() * sigma()), 1);
1269 int processing_threshold = MIN2(cg1r->green_zone() + processing_threshold_delta,
1270 cg1r->yellow_zone());
1271 // Change the barrier params
1272 dcqs.set_process_completed_threshold(processing_threshold);
1273 dcqs.set_max_completed_queue(cg1r->red_zone());
1274 }
1275
1276 int curr_queue_size = dcqs.completed_buffers_num();
1277 if (curr_queue_size >= cg1r->yellow_zone()) {
1278 dcqs.set_completed_queue_padding(curr_queue_size);
1279 } else {
1280 dcqs.set_completed_queue_padding(0);
1281 }
1282 dcqs.notify_if_necessary();
1283 }
1284
1285 double
1286 G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards,
1287 size_t scanned_cards) {
1288 return
1289 predict_rs_update_time_ms(pending_cards) +
1290 predict_rs_scan_time_ms(scanned_cards) +
1291 predict_constant_other_time_ms();
1292 }
1293
1294 double
1295 G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards) {
1296 size_t rs_length = predict_rs_length_diff();
1297 size_t card_num;
1298 if (collector_state()->gcs_are_young()) {
1299 card_num = predict_young_card_num(rs_length);
1300 } else {
1301 card_num = predict_non_young_card_num(rs_length);
1302 }
1303 return predict_base_elapsed_time_ms(pending_cards, card_num);
1304 }
1305
1306 size_t G1CollectorPolicy::predict_bytes_to_copy(HeapRegion* hr) {
1307 size_t bytes_to_copy;
1308 if (hr->is_marked())
1309 bytes_to_copy = hr->max_live_bytes();
1310 else {
1311 assert(hr->is_young() && hr->age_in_surv_rate_group() != -1, "invariant");
1312 int age = hr->age_in_surv_rate_group();
1313 double yg_surv_rate = predict_yg_surv_rate(age, hr->surv_rate_group());
1314 bytes_to_copy = (size_t) ((double) hr->used() * yg_surv_rate);
1315 }
1316 return bytes_to_copy;
1317 }
1318
1319 double
1320 G1CollectorPolicy::predict_region_elapsed_time_ms(HeapRegion* hr,
1321 bool for_young_gc) {
1322 size_t rs_length = hr->rem_set()->occupied();
1323 size_t card_num;
1324
1325 // Predicting the number of cards is based on which type of GC
1326 // we're predicting for.
1327 if (for_young_gc) {
1328 card_num = predict_young_card_num(rs_length);
1329 } else {
1330 card_num = predict_non_young_card_num(rs_length);
1331 }
1332 size_t bytes_to_copy = predict_bytes_to_copy(hr);
1333
1334 double region_elapsed_time_ms =
1335 predict_rs_scan_time_ms(card_num) +
1336 predict_object_copy_time_ms(bytes_to_copy);
1337
1338 // The prediction of the "other" time for this region is based
1339 // upon the region type and NOT the GC type.
1340 if (hr->is_young()) {
1341 region_elapsed_time_ms += predict_young_other_time_ms(1);
1342 } else {
1343 region_elapsed_time_ms += predict_non_young_other_time_ms(1);
1344 }
1345 return region_elapsed_time_ms;
1346 }
1347
1348 void
1349 G1CollectorPolicy::init_cset_region_lengths(uint eden_cset_region_length,
1350 uint survivor_cset_region_length) {
1351 _eden_cset_region_length = eden_cset_region_length;
1352 _survivor_cset_region_length = survivor_cset_region_length;
1353 _old_cset_region_length = 0;
1354 }
1355
1356 void G1CollectorPolicy::set_recorded_rs_lengths(size_t rs_lengths) {
1357 _recorded_rs_lengths = rs_lengths;
1358 }
1359
1360 void G1CollectorPolicy::update_recent_gc_times(double end_time_sec,
1361 double elapsed_ms) {
1362 _recent_gc_times_ms->add(elapsed_ms);
1363 _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec);
1364 _prev_collection_pause_end_ms = end_time_sec * 1000.0;
1365 }
1366
1367 size_t G1CollectorPolicy::expansion_amount() {
1368 double recent_gc_overhead = recent_avg_pause_time_ratio() * 100.0;
1369 double threshold = _gc_overhead_perc;
1370 if (recent_gc_overhead > threshold) {
1371 // We will double the existing space, or take
1372 // G1ExpandByPercentOfAvailable % of the available expansion
1373 // space, whichever is smaller, bounded below by a minimum
1374 // expansion (unless that's all that's left.)
1375 const size_t min_expand_bytes = 1*M;
1376 size_t reserved_bytes = _g1->max_capacity();
1377 size_t committed_bytes = _g1->capacity();
1378 size_t uncommitted_bytes = reserved_bytes - committed_bytes;
1379 size_t expand_bytes;
1380 size_t expand_bytes_via_pct =
1381 uncommitted_bytes * G1ExpandByPercentOfAvailable / 100;
1382 expand_bytes = MIN2(expand_bytes_via_pct, committed_bytes);
1383 expand_bytes = MAX2(expand_bytes, min_expand_bytes);
1384 expand_bytes = MIN2(expand_bytes, uncommitted_bytes);
1385
1386 ergo_verbose5(ErgoHeapSizing,
1387 "attempt heap expansion",
1388 ergo_format_reason("recent GC overhead higher than "
1389 "threshold after GC")
1390 ergo_format_perc("recent GC overhead")
1391 ergo_format_perc("threshold")
1392 ergo_format_byte("uncommitted")
1393 ergo_format_byte_perc("calculated expansion amount"),
1394 recent_gc_overhead, threshold,
1395 uncommitted_bytes,
1396 expand_bytes_via_pct, (double) G1ExpandByPercentOfAvailable);
1397
1398 return expand_bytes;
1399 } else {
1400 return 0;
1401 }
1402 }
1403
1404 void G1CollectorPolicy::print_tracing_info() const {
1405 _trace_young_gen_time_data.print();
1406 _trace_old_gen_time_data.print();
1407 }
1408
1409 void G1CollectorPolicy::print_yg_surv_rate_info() const {
1410 #ifndef PRODUCT
1411 _short_lived_surv_rate_group->print_surv_rate_summary();
1412 // add this call for any other surv rate groups
1413 #endif // PRODUCT
1414 }
1415
1416 bool G1CollectorPolicy::is_young_list_full() {
1417 uint young_list_length = _g1->young_list()->length();
1418 uint young_list_target_length = _young_list_target_length;
1419 return young_list_length >= young_list_target_length;
1420 }
1421
1422 bool G1CollectorPolicy::can_expand_young_list() {
1423 uint young_list_length = _g1->young_list()->length();
1424 uint young_list_max_length = _young_list_max_length;
1425 return young_list_length < young_list_max_length;
1426 }
1427
1428 void G1CollectorPolicy::update_max_gc_locker_expansion() {
1429 uint expansion_region_num = 0;
1430 if (GCLockerEdenExpansionPercent > 0) {
1431 double perc = (double) GCLockerEdenExpansionPercent / 100.0;
1432 double expansion_region_num_d = perc * (double) _young_list_target_length;
1433 // We use ceiling so that if expansion_region_num_d is > 0.0 (but
1434 // less than 1.0) we'll get 1.
1435 expansion_region_num = (uint) ceil(expansion_region_num_d);
1436 } else {
1437 assert(expansion_region_num == 0, "sanity");
1438 }
1439 _young_list_max_length = _young_list_target_length + expansion_region_num;
1440 assert(_young_list_target_length <= _young_list_max_length, "post-condition");
1441 }
1442
1443 // Calculates survivor space parameters.
1444 void G1CollectorPolicy::update_survivors_policy() {
1445 double max_survivor_regions_d =
1446 (double) _young_list_target_length / (double) SurvivorRatio;
1447 // We use ceiling so that if max_survivor_regions_d is > 0.0 (but
1448 // smaller than 1.0) we'll get 1.
1449 _max_survivor_regions = (uint) ceil(max_survivor_regions_d);
1450
1451 _tenuring_threshold = _survivors_age_table.compute_tenuring_threshold(
1452 HeapRegion::GrainWords * _max_survivor_regions);
1453 }
1454
1455 bool G1CollectorPolicy::force_initial_mark_if_outside_cycle(
1456 GCCause::Cause gc_cause) {
1457 bool during_cycle = _g1->concurrent_mark()->cmThread()->during_cycle();
1458 if (!during_cycle) {
1459 ergo_verbose1(ErgoConcCycles,
1460 "request concurrent cycle initiation",
1461 ergo_format_reason("requested by GC cause")
1462 ergo_format_str("GC cause"),
1463 GCCause::to_string(gc_cause));
1464 collector_state()->set_initiate_conc_mark_if_possible(true);
1465 return true;
1466 } else {
1467 ergo_verbose1(ErgoConcCycles,
1468 "do not request concurrent cycle initiation",
1469 ergo_format_reason("concurrent cycle already in progress")
1470 ergo_format_str("GC cause"),
1471 GCCause::to_string(gc_cause));
1472 return false;
1473 }
1474 }
1475
1476 void
1477 G1CollectorPolicy::decide_on_conc_mark_initiation() {
1478 // We are about to decide on whether this pause will be an
1479 // initial-mark pause.
1480
1481 // First, collector_state()->during_initial_mark_pause() should not be already set. We
1482 // will set it here if we have to. However, it should be cleared by
1483 // the end of the pause (it's only set for the duration of an
1484 // initial-mark pause).
1485 assert(!collector_state()->during_initial_mark_pause(), "pre-condition");
1486
1487 if (collector_state()->initiate_conc_mark_if_possible()) {
1488 // We had noticed on a previous pause that the heap occupancy has
1489 // gone over the initiating threshold and we should start a
1490 // concurrent marking cycle. So we might initiate one.
1491
1492 bool during_cycle = _g1->concurrent_mark()->cmThread()->during_cycle();
1493 if (!during_cycle) {
1494 // The concurrent marking thread is not "during a cycle", i.e.,
1495 // it has completed the last one. So we can go ahead and
1496 // initiate a new cycle.
1497
1498 collector_state()->set_during_initial_mark_pause(true);
1499 // We do not allow mixed GCs during marking.
1500 if (!collector_state()->gcs_are_young()) {
1501 collector_state()->set_gcs_are_young(true);
1502 ergo_verbose0(ErgoMixedGCs,
1503 "end mixed GCs",
1504 ergo_format_reason("concurrent cycle is about to start"));
1505 }
1506
1507 // And we can now clear initiate_conc_mark_if_possible() as
1508 // we've already acted on it.
1509 collector_state()->set_initiate_conc_mark_if_possible(false);
1510
1511 ergo_verbose0(ErgoConcCycles,
1512 "initiate concurrent cycle",
1513 ergo_format_reason("concurrent cycle initiation requested"));
1514 } else {
1515 // The concurrent marking thread is still finishing up the
1516 // previous cycle. If we start one right now the two cycles
1517 // overlap. In particular, the concurrent marking thread might
1518 // be in the process of clearing the next marking bitmap (which
1519 // we will use for the next cycle if we start one). Starting a
1520 // cycle now will be bad given that parts of the marking
1521 // information might get cleared by the marking thread. And we
1522 // cannot wait for the marking thread to finish the cycle as it
1523 // periodically yields while clearing the next marking bitmap
1524 // and, if it's in a yield point, it's waiting for us to
1525 // finish. So, at this point we will not start a cycle and we'll
1526 // let the concurrent marking thread complete the last one.
1527 ergo_verbose0(ErgoConcCycles,
1528 "do not initiate concurrent cycle",
1529 ergo_format_reason("concurrent cycle already in progress"));
1530 }
1531 }
1532 }
1533
1534 class ParKnownGarbageHRClosure: public HeapRegionClosure {
1535 G1CollectedHeap* _g1h;
1536 CSetChooserParUpdater _cset_updater;
1537
1538 public:
1539 ParKnownGarbageHRClosure(CollectionSetChooser* hrSorted,
1540 uint chunk_size) :
1541 _g1h(G1CollectedHeap::heap()),
1542 _cset_updater(hrSorted, true /* parallel */, chunk_size) { }
1543
1544 bool doHeapRegion(HeapRegion* r) {
1545 // Do we have any marking information for this region?
1546 if (r->is_marked()) {
1547 // We will skip any region that's currently used as an old GC
1548 // alloc region (we should not consider those for collection
1549 // before we fill them up).
1550 if (_cset_updater.should_add(r) && !_g1h->is_old_gc_alloc_region(r)) {
1551 _cset_updater.add_region(r);
1552 }
1553 }
1554 return false;
1555 }
1556 };
1557
1558 class ParKnownGarbageTask: public AbstractGangTask {
1559 CollectionSetChooser* _hrSorted;
1560 uint _chunk_size;
1561 G1CollectedHeap* _g1;
1562 HeapRegionClaimer _hrclaimer;
1563
1564 public:
1565 ParKnownGarbageTask(CollectionSetChooser* hrSorted, uint chunk_size, uint n_workers) :
1566 AbstractGangTask("ParKnownGarbageTask"),
1567 _hrSorted(hrSorted), _chunk_size(chunk_size),
1568 _g1(G1CollectedHeap::heap()), _hrclaimer(n_workers) {}
1569
1570 void work(uint worker_id) {
1571 ParKnownGarbageHRClosure parKnownGarbageCl(_hrSorted, _chunk_size);
1572 _g1->heap_region_par_iterate(&parKnownGarbageCl, worker_id, &_hrclaimer);
1573 }
1574 };
1575
1576 uint G1CollectorPolicy::calculate_parallel_work_chunk_size(uint n_workers, uint n_regions) {
1577 assert(n_workers > 0, "Active gc workers should be greater than 0");
1578 const uint overpartition_factor = 4;
1579 const uint min_chunk_size = MAX2(n_regions / n_workers, 1U);
1580 return MAX2(n_regions / (n_workers * overpartition_factor), min_chunk_size);
1581 }
1582
1583 void
1584 G1CollectorPolicy::record_concurrent_mark_cleanup_end(uint n_workers) {
1585 _collectionSetChooser->clear();
1586
1587 uint n_regions = _g1->num_regions();
1588 uint chunk_size = calculate_parallel_work_chunk_size(n_workers, n_regions);
1589 _collectionSetChooser->prepare_for_par_region_addition(n_regions, chunk_size);
1590 ParKnownGarbageTask par_known_garbage_task(_collectionSetChooser, chunk_size, n_workers);
1591 _g1->workers()->run_task(&par_known_garbage_task);
1592
1593 _collectionSetChooser->sort_regions();
1594
1595 double end_sec = os::elapsedTime();
1596 double elapsed_time_ms = (end_sec - _mark_cleanup_start_sec) * 1000.0;
1597 _concurrent_mark_cleanup_times_ms->add(elapsed_time_ms);
1598 _cur_mark_stop_world_time_ms += elapsed_time_ms;
1599 _prev_collection_pause_end_ms += elapsed_time_ms;
1600 _mmu_tracker->add_pause(_mark_cleanup_start_sec, end_sec, true);
1601 }
1602
1603 // Add the heap region at the head of the non-incremental collection set
1604 void G1CollectorPolicy::add_old_region_to_cset(HeapRegion* hr) {
1605 assert(_inc_cset_build_state == Active, "Precondition");
1606 assert(hr->is_old(), "the region should be old");
1607
1608 assert(!hr->in_collection_set(), "should not already be in the CSet");
1609 hr->set_in_collection_set(true);
1610 hr->set_next_in_collection_set(_collection_set);
1611 _collection_set = hr;
1612 _collection_set_bytes_used_before += hr->used();
1613 _g1->register_old_region_with_in_cset_fast_test(hr);
1614 size_t rs_length = hr->rem_set()->occupied();
1615 _recorded_rs_lengths += rs_length;
1616 _old_cset_region_length += 1;
1617 }
1618
1619 // Initialize the per-collection-set information
1620 void G1CollectorPolicy::start_incremental_cset_building() {
1621 assert(_inc_cset_build_state == Inactive, "Precondition");
1622
1623 _inc_cset_head = NULL;
1624 _inc_cset_tail = NULL;
1625 _inc_cset_bytes_used_before = 0;
1626
1627 _inc_cset_max_finger = 0;
1628 _inc_cset_recorded_rs_lengths = 0;
1629 _inc_cset_recorded_rs_lengths_diffs = 0;
1630 _inc_cset_predicted_elapsed_time_ms = 0.0;
1631 _inc_cset_predicted_elapsed_time_ms_diffs = 0.0;
1632 _inc_cset_build_state = Active;
1633 }
1634
1635 void G1CollectorPolicy::finalize_incremental_cset_building() {
1636 assert(_inc_cset_build_state == Active, "Precondition");
1637 assert(SafepointSynchronize::is_at_safepoint(), "should be at a safepoint");
1638
1639 // The two "main" fields, _inc_cset_recorded_rs_lengths and
1640 // _inc_cset_predicted_elapsed_time_ms, are updated by the thread
1641 // that adds a new region to the CSet. Further updates by the
1642 // concurrent refinement thread that samples the young RSet lengths
1643 // are accumulated in the *_diffs fields. Here we add the diffs to
1644 // the "main" fields.
1645
1646 if (_inc_cset_recorded_rs_lengths_diffs >= 0) {
1647 _inc_cset_recorded_rs_lengths += _inc_cset_recorded_rs_lengths_diffs;
1648 } else {
1649 // This is defensive. The diff should in theory be always positive
1650 // as RSets can only grow between GCs. However, given that we
1651 // sample their size concurrently with other threads updating them
1652 // it's possible that we might get the wrong size back, which
1653 // could make the calculations somewhat inaccurate.
1654 size_t diffs = (size_t) (-_inc_cset_recorded_rs_lengths_diffs);
1655 if (_inc_cset_recorded_rs_lengths >= diffs) {
1656 _inc_cset_recorded_rs_lengths -= diffs;
1657 } else {
1658 _inc_cset_recorded_rs_lengths = 0;
1659 }
1660 }
1661 _inc_cset_predicted_elapsed_time_ms +=
1662 _inc_cset_predicted_elapsed_time_ms_diffs;
1663
1664 _inc_cset_recorded_rs_lengths_diffs = 0;
1665 _inc_cset_predicted_elapsed_time_ms_diffs = 0.0;
1666 }
1667
1668 void G1CollectorPolicy::add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length) {
1669 // This routine is used when:
1670 // * adding survivor regions to the incremental cset at the end of an
1671 // evacuation pause,
1672 // * adding the current allocation region to the incremental cset
1673 // when it is retired, and
1674 // * updating existing policy information for a region in the
1675 // incremental cset via young list RSet sampling.
1676 // Therefore this routine may be called at a safepoint by the
1677 // VM thread, or in-between safepoints by mutator threads (when
1678 // retiring the current allocation region) or a concurrent
1679 // refine thread (RSet sampling).
1680
1681 double region_elapsed_time_ms = predict_region_elapsed_time_ms(hr, collector_state()->gcs_are_young());
1682 size_t used_bytes = hr->used();
1683 _inc_cset_recorded_rs_lengths += rs_length;
1684 _inc_cset_predicted_elapsed_time_ms += region_elapsed_time_ms;
1685 _inc_cset_bytes_used_before += used_bytes;
1686
1687 // Cache the values we have added to the aggregated information
1688 // in the heap region in case we have to remove this region from
1689 // the incremental collection set, or it is updated by the
1690 // rset sampling code
1691 hr->set_recorded_rs_length(rs_length);
1692 hr->set_predicted_elapsed_time_ms(region_elapsed_time_ms);
1693 }
1694
1695 void G1CollectorPolicy::update_incremental_cset_info(HeapRegion* hr,
1696 size_t new_rs_length) {
1697 // Update the CSet information that is dependent on the new RS length
1698 assert(hr->is_young(), "Precondition");
1699 assert(!SafepointSynchronize::is_at_safepoint(),
1700 "should not be at a safepoint");
1701
1702 // We could have updated _inc_cset_recorded_rs_lengths and
1703 // _inc_cset_predicted_elapsed_time_ms directly but we'd need to do
1704 // that atomically, as this code is executed by a concurrent
1705 // refinement thread, potentially concurrently with a mutator thread
1706 // allocating a new region and also updating the same fields. To
1707 // avoid the atomic operations we accumulate these updates on two
1708 // separate fields (*_diffs) and we'll just add them to the "main"
1709 // fields at the start of a GC.
1710
1711 ssize_t old_rs_length = (ssize_t) hr->recorded_rs_length();
1712 ssize_t rs_lengths_diff = (ssize_t) new_rs_length - old_rs_length;
1713 _inc_cset_recorded_rs_lengths_diffs += rs_lengths_diff;
1714
1715 double old_elapsed_time_ms = hr->predicted_elapsed_time_ms();
1716 double new_region_elapsed_time_ms = predict_region_elapsed_time_ms(hr, collector_state()->gcs_are_young());
1717 double elapsed_ms_diff = new_region_elapsed_time_ms - old_elapsed_time_ms;
1718 _inc_cset_predicted_elapsed_time_ms_diffs += elapsed_ms_diff;
1719
1720 hr->set_recorded_rs_length(new_rs_length);
1721 hr->set_predicted_elapsed_time_ms(new_region_elapsed_time_ms);
1722 }
1723
1724 void G1CollectorPolicy::add_region_to_incremental_cset_common(HeapRegion* hr) {
1725 assert(hr->is_young(), "invariant");
1726 assert(hr->young_index_in_cset() > -1, "should have already been set");
1727 assert(_inc_cset_build_state == Active, "Precondition");
1728
1729 // We need to clear and set the cached recorded/cached collection set
1730 // information in the heap region here (before the region gets added
1731 // to the collection set). An individual heap region's cached values
1732 // are calculated, aggregated with the policy collection set info,
1733 // and cached in the heap region here (initially) and (subsequently)
1734 // by the Young List sampling code.
1735
1736 size_t rs_length = hr->rem_set()->occupied();
1737 add_to_incremental_cset_info(hr, rs_length);
1738
1739 HeapWord* hr_end = hr->end();
1740 _inc_cset_max_finger = MAX2(_inc_cset_max_finger, hr_end);
1741
1742 assert(!hr->in_collection_set(), "invariant");
1743 hr->set_in_collection_set(true);
1744 assert( hr->next_in_collection_set() == NULL, "invariant");
1745
1746 _g1->register_young_region_with_in_cset_fast_test(hr);
1747 }
1748
1749 // Add the region at the RHS of the incremental cset
1750 void G1CollectorPolicy::add_region_to_incremental_cset_rhs(HeapRegion* hr) {
1751 // We should only ever be appending survivors at the end of a pause
1752 assert(hr->is_survivor(), "Logic");
1753
1754 // Do the 'common' stuff
1755 add_region_to_incremental_cset_common(hr);
1756
1757 // Now add the region at the right hand side
1758 if (_inc_cset_tail == NULL) {
1759 assert(_inc_cset_head == NULL, "invariant");
1760 _inc_cset_head = hr;
1761 } else {
1762 _inc_cset_tail->set_next_in_collection_set(hr);
1763 }
1764 _inc_cset_tail = hr;
1765 }
1766
1767 // Add the region to the LHS of the incremental cset
1768 void G1CollectorPolicy::add_region_to_incremental_cset_lhs(HeapRegion* hr) {
1769 // Survivors should be added to the RHS at the end of a pause
1770 assert(hr->is_eden(), "Logic");
1771
1772 // Do the 'common' stuff
1773 add_region_to_incremental_cset_common(hr);
1774
1775 // Add the region at the left hand side
1776 hr->set_next_in_collection_set(_inc_cset_head);
1777 if (_inc_cset_head == NULL) {
1778 assert(_inc_cset_tail == NULL, "Invariant");
1779 _inc_cset_tail = hr;
1780 }
1781 _inc_cset_head = hr;
1782 }
1783
1784 #ifndef PRODUCT
1785 void G1CollectorPolicy::print_collection_set(HeapRegion* list_head, outputStream* st) {
1786 assert(list_head == inc_cset_head() || list_head == collection_set(), "must be");
1787
1788 st->print_cr("\nCollection_set:");
1789 HeapRegion* csr = list_head;
1790 while (csr != NULL) {
1791 HeapRegion* next = csr->next_in_collection_set();
1792 assert(csr->in_collection_set(), "bad CS");
1793 st->print_cr(" "HR_FORMAT", P: "PTR_FORMAT "N: "PTR_FORMAT", age: %4d",
1794 HR_FORMAT_PARAMS(csr),
1795 csr->prev_top_at_mark_start(), csr->next_top_at_mark_start(),
1796 csr->age_in_surv_rate_group_cond());
1797 csr = next;
1798 }
1799 }
1800 #endif // !PRODUCT
1801
1802 double G1CollectorPolicy::reclaimable_bytes_perc(size_t reclaimable_bytes) {
1803 // Returns the given amount of reclaimable bytes (that represents
1804 // the amount of reclaimable space still to be collected) as a
1805 // percentage of the current heap capacity.
1806 size_t capacity_bytes = _g1->capacity();
1807 return (double) reclaimable_bytes * 100.0 / (double) capacity_bytes;
1808 }
1809
1810 bool G1CollectorPolicy::next_gc_should_be_mixed(const char* true_action_str,
1811 const char* false_action_str) {
1812 CollectionSetChooser* cset_chooser = _collectionSetChooser;
1813 if (cset_chooser->is_empty()) {
1814 ergo_verbose0(ErgoMixedGCs,
1815 false_action_str,
1816 ergo_format_reason("candidate old regions not available"));
1817 return false;
1818 }
1819
1820 // Is the amount of uncollected reclaimable space above G1HeapWastePercent?
1821 size_t reclaimable_bytes = cset_chooser->remaining_reclaimable_bytes();
1822 double reclaimable_perc = reclaimable_bytes_perc(reclaimable_bytes);
1823 double threshold = (double) G1HeapWastePercent;
1824 if (reclaimable_perc <= threshold) {
1825 ergo_verbose4(ErgoMixedGCs,
1826 false_action_str,
1827 ergo_format_reason("reclaimable percentage not over threshold")
1828 ergo_format_region("candidate old regions")
1829 ergo_format_byte_perc("reclaimable")
1830 ergo_format_perc("threshold"),
1831 cset_chooser->remaining_regions(),
1832 reclaimable_bytes,
1833 reclaimable_perc, threshold);
1834 return false;
1835 }
1836
1837 ergo_verbose4(ErgoMixedGCs,
1838 true_action_str,
1839 ergo_format_reason("candidate old regions available")
1840 ergo_format_region("candidate old regions")
1841 ergo_format_byte_perc("reclaimable")
1842 ergo_format_perc("threshold"),
1843 cset_chooser->remaining_regions(),
1844 reclaimable_bytes,
1845 reclaimable_perc, threshold);
1846 return true;
1847 }
1848
1849 uint G1CollectorPolicy::calc_min_old_cset_length() {
1850 // The min old CSet region bound is based on the maximum desired
1851 // number of mixed GCs after a cycle. I.e., even if some old regions
1852 // look expensive, we should add them to the CSet anyway to make
1853 // sure we go through the available old regions in no more than the
1854 // maximum desired number of mixed GCs.
1855 //
1856 // The calculation is based on the number of marked regions we added
1857 // to the CSet chooser in the first place, not how many remain, so
1858 // that the result is the same during all mixed GCs that follow a cycle.
1859
1860 const size_t region_num = (size_t) _collectionSetChooser->length();
1861 const size_t gc_num = (size_t) MAX2(G1MixedGCCountTarget, (uintx) 1);
1862 size_t result = region_num / gc_num;
1863 // emulate ceiling
1864 if (result * gc_num < region_num) {
1865 result += 1;
1866 }
1867 return (uint) result;
1868 }
1869
1870 uint G1CollectorPolicy::calc_max_old_cset_length() {
1871 // The max old CSet region bound is based on the threshold expressed
1872 // as a percentage of the heap size. I.e., it should bound the
1873 // number of old regions added to the CSet irrespective of how many
1874 // of them are available.
1875
1876 G1CollectedHeap* g1h = G1CollectedHeap::heap();
1877 const size_t region_num = g1h->num_regions();
1878 const size_t perc = (size_t) G1OldCSetRegionThresholdPercent;
1879 size_t result = region_num * perc / 100;
1880 // emulate ceiling
1881 if (100 * result < region_num * perc) {
1882 result += 1;
1883 }
1884 return (uint) result;
1885 }
1886
1887
1888 void G1CollectorPolicy::finalize_cset(double target_pause_time_ms, EvacuationInfo& evacuation_info) {
1889 double young_start_time_sec = os::elapsedTime();
1890
1891 YoungList* young_list = _g1->young_list();
1892 finalize_incremental_cset_building();
1893
1894 guarantee(target_pause_time_ms > 0.0,
1895 err_msg("target_pause_time_ms = %1.6lf should be positive",
1896 target_pause_time_ms));
1897 guarantee(_collection_set == NULL, "Precondition");
1898
1899 double base_time_ms = predict_base_elapsed_time_ms(_pending_cards);
1900 double predicted_pause_time_ms = base_time_ms;
1901 double time_remaining_ms = MAX2(target_pause_time_ms - base_time_ms, 0.0);
1902
1903 ergo_verbose4(ErgoCSetConstruction | ErgoHigh,
1904 "start choosing CSet",
1905 ergo_format_size("_pending_cards")
1906 ergo_format_ms("predicted base time")
1907 ergo_format_ms("remaining time")
1908 ergo_format_ms("target pause time"),
1909 _pending_cards, base_time_ms, time_remaining_ms, target_pause_time_ms);
1910
1911 collector_state()->set_last_gc_was_young(collector_state()->gcs_are_young() ? true : false);
1912
1913 if (collector_state()->last_gc_was_young()) {
1914 _trace_young_gen_time_data.increment_young_collection_count();
1915 } else {
1916 _trace_young_gen_time_data.increment_mixed_collection_count();
1917 }
1918
1919 // The young list is laid with the survivor regions from the previous
1920 // pause are appended to the RHS of the young list, i.e.
1921 // [Newly Young Regions ++ Survivors from last pause].
1922
1923 uint survivor_region_length = young_list->survivor_length();
1924 uint eden_region_length = young_list->length() - survivor_region_length;
1925 init_cset_region_lengths(eden_region_length, survivor_region_length);
1926
1927 HeapRegion* hr = young_list->first_survivor_region();
1928 while (hr != NULL) {
1929 assert(hr->is_survivor(), "badly formed young list");
1930 // There is a convention that all the young regions in the CSet
1931 // are tagged as "eden", so we do this for the survivors here. We
1932 // use the special set_eden_pre_gc() as it doesn't check that the
1933 // region is free (which is not the case here).
1934 hr->set_eden_pre_gc();
1935 hr = hr->get_next_young_region();
1936 }
1937
1938 // Clear the fields that point to the survivor list - they are all young now.
1939 young_list->clear_survivors();
1940
1941 _collection_set = _inc_cset_head;
1942 _collection_set_bytes_used_before = _inc_cset_bytes_used_before;
1943 time_remaining_ms = MAX2(time_remaining_ms - _inc_cset_predicted_elapsed_time_ms, 0.0);
1944 predicted_pause_time_ms += _inc_cset_predicted_elapsed_time_ms;
1945
1946 ergo_verbose3(ErgoCSetConstruction | ErgoHigh,
1947 "add young regions to CSet",
1948 ergo_format_region("eden")
1949 ergo_format_region("survivors")
1950 ergo_format_ms("predicted young region time"),
1951 eden_region_length, survivor_region_length,
1952 _inc_cset_predicted_elapsed_time_ms);
1953
1954 // The number of recorded young regions is the incremental
1955 // collection set's current size
1956 set_recorded_rs_lengths(_inc_cset_recorded_rs_lengths);
1957
1958 double young_end_time_sec = os::elapsedTime();
1959 phase_times()->record_young_cset_choice_time_ms((young_end_time_sec - young_start_time_sec) * 1000.0);
1960
1961 // Set the start of the non-young choice time.
1962 double non_young_start_time_sec = young_end_time_sec;
1963
1964 if (!collector_state()->gcs_are_young()) {
1965 CollectionSetChooser* cset_chooser = _collectionSetChooser;
1966 cset_chooser->verify();
1967 const uint min_old_cset_length = calc_min_old_cset_length();
1968 const uint max_old_cset_length = calc_max_old_cset_length();
1969
1970 uint expensive_region_num = 0;
1971 bool check_time_remaining = adaptive_young_list_length();
1972
1973 HeapRegion* hr = cset_chooser->peek();
1974 while (hr != NULL) {
1975 if (old_cset_region_length() >= max_old_cset_length) {
1976 // Added maximum number of old regions to the CSet.
1977 ergo_verbose2(ErgoCSetConstruction,
1978 "finish adding old regions to CSet",
1979 ergo_format_reason("old CSet region num reached max")
1980 ergo_format_region("old")
1981 ergo_format_region("max"),
1982 old_cset_region_length(), max_old_cset_length);
1983 break;
1984 }
1985
1986
1987 // Stop adding regions if the remaining reclaimable space is
1988 // not above G1HeapWastePercent.
1989 size_t reclaimable_bytes = cset_chooser->remaining_reclaimable_bytes();
1990 double reclaimable_perc = reclaimable_bytes_perc(reclaimable_bytes);
1991 double threshold = (double) G1HeapWastePercent;
1992 if (reclaimable_perc <= threshold) {
1993 // We've added enough old regions that the amount of uncollected
1994 // reclaimable space is at or below the waste threshold. Stop
1995 // adding old regions to the CSet.
1996 ergo_verbose5(ErgoCSetConstruction,
1997 "finish adding old regions to CSet",
1998 ergo_format_reason("reclaimable percentage not over threshold")
1999 ergo_format_region("old")
2000 ergo_format_region("max")
2001 ergo_format_byte_perc("reclaimable")
2002 ergo_format_perc("threshold"),
2003 old_cset_region_length(),
2004 max_old_cset_length,
2005 reclaimable_bytes,
2006 reclaimable_perc, threshold);
2007 break;
2008 }
2009
2010 double predicted_time_ms = predict_region_elapsed_time_ms(hr, collector_state()->gcs_are_young());
2011 if (check_time_remaining) {
2012 if (predicted_time_ms > time_remaining_ms) {
2013 // Too expensive for the current CSet.
2014
2015 if (old_cset_region_length() >= min_old_cset_length) {
2016 // We have added the minimum number of old regions to the CSet,
2017 // we are done with this CSet.
2018 ergo_verbose4(ErgoCSetConstruction,
2019 "finish adding old regions to CSet",
2020 ergo_format_reason("predicted time is too high")
2021 ergo_format_ms("predicted time")
2022 ergo_format_ms("remaining time")
2023 ergo_format_region("old")
2024 ergo_format_region("min"),
2025 predicted_time_ms, time_remaining_ms,
2026 old_cset_region_length(), min_old_cset_length);
2027 break;
2028 }
2029
2030 // We'll add it anyway given that we haven't reached the
2031 // minimum number of old regions.
2032 expensive_region_num += 1;
2033 }
2034 } else {
2035 if (old_cset_region_length() >= min_old_cset_length) {
2036 // In the non-auto-tuning case, we'll finish adding regions
2037 // to the CSet if we reach the minimum.
2038 ergo_verbose2(ErgoCSetConstruction,
2039 "finish adding old regions to CSet",
2040 ergo_format_reason("old CSet region num reached min")
2041 ergo_format_region("old")
2042 ergo_format_region("min"),
2043 old_cset_region_length(), min_old_cset_length);
2044 break;
2045 }
2046 }
2047
2048 // We will add this region to the CSet.
2049 time_remaining_ms = MAX2(time_remaining_ms - predicted_time_ms, 0.0);
2050 predicted_pause_time_ms += predicted_time_ms;
2051 cset_chooser->remove_and_move_to_next(hr);
2052 _g1->old_set_remove(hr);
2053 add_old_region_to_cset(hr);
2054
2055 hr = cset_chooser->peek();
2056 }
2057 if (hr == NULL) {
2058 ergo_verbose0(ErgoCSetConstruction,
2059 "finish adding old regions to CSet",
2060 ergo_format_reason("candidate old regions not available"));
2061 }
2062
2063 if (expensive_region_num > 0) {
2064 // We print the information once here at the end, predicated on
2065 // whether we added any apparently expensive regions or not, to
2066 // avoid generating output per region.
2067 ergo_verbose4(ErgoCSetConstruction,
2068 "added expensive regions to CSet",
2069 ergo_format_reason("old CSet region num not reached min")
2070 ergo_format_region("old")
2071 ergo_format_region("expensive")
2072 ergo_format_region("min")
2073 ergo_format_ms("remaining time"),
2074 old_cset_region_length(),
2075 expensive_region_num,
2076 min_old_cset_length,
2077 time_remaining_ms);
2078 }
2079
2080 cset_chooser->verify();
2081 }
2082
2083 stop_incremental_cset_building();
2084
2085 ergo_verbose5(ErgoCSetConstruction,
2086 "finish choosing CSet",
2087 ergo_format_region("eden")
2088 ergo_format_region("survivors")
2089 ergo_format_region("old")
2090 ergo_format_ms("predicted pause time")
2091 ergo_format_ms("target pause time"),
2092 eden_region_length, survivor_region_length,
2093 old_cset_region_length(),
2094 predicted_pause_time_ms, target_pause_time_ms);
2095
2096 double non_young_end_time_sec = os::elapsedTime();
2097 phase_times()->record_non_young_cset_choice_time_ms((non_young_end_time_sec - non_young_start_time_sec) * 1000.0);
2098 evacuation_info.set_collectionset_regions(cset_region_length());
2099 }
2100
2101 void TraceYoungGenTimeData::record_start_collection(double time_to_stop_the_world_ms) {
2102 if(TraceYoungGenTime) {
2103 _all_stop_world_times_ms.add(time_to_stop_the_world_ms);
2104 }
2105 }
2106
2107 void TraceYoungGenTimeData::record_yield_time(double yield_time_ms) {
2108 if(TraceYoungGenTime) {
2109 _all_yield_times_ms.add(yield_time_ms);
2110 }
2111 }
2112
2113 void TraceYoungGenTimeData::record_end_collection(double pause_time_ms, G1GCPhaseTimes* phase_times) {
2114 if(TraceYoungGenTime) {
2115 _total.add(pause_time_ms);
2116 _other.add(pause_time_ms - phase_times->accounted_time_ms());
2117 _root_region_scan_wait.add(phase_times->root_region_scan_wait_time_ms());
2118 _parallel.add(phase_times->cur_collection_par_time_ms());
2119 _ext_root_scan.add(phase_times->average_last_ext_root_scan_time());
2120 _satb_filtering.add(phase_times->average_last_satb_filtering_times_ms());
2121 _update_rs.add(phase_times->average_last_update_rs_time());
2122 _scan_rs.add(phase_times->average_last_scan_rs_time());
2123 _obj_copy.add(phase_times->average_last_obj_copy_time());
2124 _termination.add(phase_times->average_last_termination_time());
2125
2126 double parallel_known_time = phase_times->average_last_ext_root_scan_time() +
2127 phase_times->average_last_satb_filtering_times_ms() +
2128 phase_times->average_last_update_rs_time() +
2129 phase_times->average_last_scan_rs_time() +
2130 phase_times->average_last_obj_copy_time() +
2131 + phase_times->average_last_termination_time();
2132
2133 double parallel_other_time = phase_times->cur_collection_par_time_ms() - parallel_known_time;
2134 _parallel_other.add(parallel_other_time);
2135 _clear_ct.add(phase_times->cur_clear_ct_time_ms());
2136 }
2137 }
2138
2139 void TraceYoungGenTimeData::increment_young_collection_count() {
2140 if(TraceYoungGenTime) {
2141 ++_young_pause_num;
2142 }
2143 }
2144
2145 void TraceYoungGenTimeData::increment_mixed_collection_count() {
2146 if(TraceYoungGenTime) {
2147 ++_mixed_pause_num;
2148 }
2149 }
2150
2151 void TraceYoungGenTimeData::print_summary(const char* str,
2152 const NumberSeq* seq) const {
2153 double sum = seq->sum();
2154 gclog_or_tty->print_cr("%-27s = %8.2lf s (avg = %8.2lf ms)",
2155 str, sum / 1000.0, seq->avg());
2156 }
2157
2158 void TraceYoungGenTimeData::print_summary_sd(const char* str,
2159 const NumberSeq* seq) const {
2160 print_summary(str, seq);
2161 gclog_or_tty->print_cr("%+45s = %5d, std dev = %8.2lf ms, max = %8.2lf ms)",
2162 "(num", seq->num(), seq->sd(), seq->maximum());
2163 }
2164
2165 void TraceYoungGenTimeData::print() const {
2166 if (!TraceYoungGenTime) {
2167 return;
2168 }
2169
2170 gclog_or_tty->print_cr("ALL PAUSES");
2171 print_summary_sd(" Total", &_total);
2172 gclog_or_tty->cr();
2173 gclog_or_tty->cr();
2174 gclog_or_tty->print_cr(" Young GC Pauses: %8d", _young_pause_num);
2175 gclog_or_tty->print_cr(" Mixed GC Pauses: %8d", _mixed_pause_num);
2176 gclog_or_tty->cr();
2177
2178 gclog_or_tty->print_cr("EVACUATION PAUSES");
2179
2180 if (_young_pause_num == 0 && _mixed_pause_num == 0) {
2181 gclog_or_tty->print_cr("none");
2182 } else {
2183 print_summary_sd(" Evacuation Pauses", &_total);
2184 print_summary(" Root Region Scan Wait", &_root_region_scan_wait);
2185 print_summary(" Parallel Time", &_parallel);
2186 print_summary(" Ext Root Scanning", &_ext_root_scan);
2187 print_summary(" SATB Filtering", &_satb_filtering);
2188 print_summary(" Update RS", &_update_rs);
2189 print_summary(" Scan RS", &_scan_rs);
2190 print_summary(" Object Copy", &_obj_copy);
2191 print_summary(" Termination", &_termination);
2192 print_summary(" Parallel Other", &_parallel_other);
2193 print_summary(" Clear CT", &_clear_ct);
2194 print_summary(" Other", &_other);
2195 }
2196 gclog_or_tty->cr();
2197
2198 gclog_or_tty->print_cr("MISC");
2199 print_summary_sd(" Stop World", &_all_stop_world_times_ms);
2200 print_summary_sd(" Yields", &_all_yield_times_ms);
2201 }
2202
2203 void TraceOldGenTimeData::record_full_collection(double full_gc_time_ms) {
2204 if (TraceOldGenTime) {
2205 _all_full_gc_times.add(full_gc_time_ms);
2206 }
2207 }
2208
2209 void TraceOldGenTimeData::print() const {
2210 if (!TraceOldGenTime) {
2211 return;
2212 }
2213
2214 if (_all_full_gc_times.num() > 0) {
2215 gclog_or_tty->print("\n%4d full_gcs: total time = %8.2f s",
2216 _all_full_gc_times.num(),
2217 _all_full_gc_times.sum() / 1000.0);
2218 gclog_or_tty->print_cr(" (avg = %8.2fms).", _all_full_gc_times.avg());
2219 gclog_or_tty->print_cr(" [std. dev = %8.2f ms, max = %8.2f ms]",
2220 _all_full_gc_times.sd(),
2221 _all_full_gc_times.maximum());
2222 }
2223 }