1 /*
2 * Copyright (c) 2002, 2016, 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.
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23 */
24
25 #include "precompiled.hpp"
26 #include "gc/parallel/parallelScavengeHeap.hpp"
27 #include "gc/parallel/psAdaptiveSizePolicy.hpp"
28 #include "gc/parallel/psGCAdaptivePolicyCounters.hpp"
29 #include "gc/parallel/psScavenge.hpp"
30 #include "gc/shared/collectorPolicy.hpp"
31 #include "gc/shared/gcCause.hpp"
32 #include "gc/shared/gcPolicyCounters.hpp"
33 #include "logging/log.hpp"
34 #include "runtime/timer.hpp"
35
36 #include <math.h>
37
38 PSAdaptiveSizePolicy::PSAdaptiveSizePolicy(size_t init_eden_size,
39 size_t init_promo_size,
40 size_t init_survivor_size,
41 size_t space_alignment,
42 double gc_pause_goal_sec,
43 double gc_minor_pause_goal_sec,
44 uint gc_cost_ratio) :
45 AdaptiveSizePolicy(init_eden_size,
46 init_promo_size,
47 init_survivor_size,
48 gc_pause_goal_sec,
49 gc_cost_ratio),
50 _collection_cost_margin_fraction(AdaptiveSizePolicyCollectionCostMargin / 100.0),
51 _space_alignment(space_alignment),
52 _live_at_last_full_gc(init_promo_size),
53 _gc_minor_pause_goal_sec(gc_minor_pause_goal_sec),
54 _latest_major_mutator_interval_seconds(0),
55 _young_gen_change_for_major_pause_count(0)
56 {
57 // Sizing policy statistics
58 _avg_major_pause =
59 new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding);
60 _avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
61 _avg_major_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
62
63 _avg_base_footprint = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight);
64 _major_pause_old_estimator =
65 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
66 _major_pause_young_estimator =
67 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
68 _major_collection_estimator =
69 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
70
71 _young_gen_size_increment_supplement = YoungGenerationSizeSupplement;
72 _old_gen_size_increment_supplement = TenuredGenerationSizeSupplement;
73
74 // Start the timers
75 _major_timer.start();
76
77 _old_gen_policy_is_ready = false;
78 }
79
80 size_t PSAdaptiveSizePolicy::calculate_free_based_on_live(size_t live, uintx ratio_as_percentage) {
81 // We want to calculate how much free memory there can be based on the
82 // amount of live data currently in the old gen. Using the formula:
83 // ratio * (free + live) = free
84 // Some equation solving later we get:
85 // free = (live * ratio) / (1 - ratio)
86
87 const double ratio = ratio_as_percentage / 100.0;
88 const double ratio_inverse = 1.0 - ratio;
89 const double tmp = live * ratio;
90 size_t free = (size_t)(tmp / ratio_inverse);
91
92 return free;
93 }
94
95 size_t PSAdaptiveSizePolicy::calculated_old_free_size_in_bytes() const {
96 size_t free_size = (size_t)(_promo_size + avg_promoted()->padded_average());
97 size_t live = ParallelScavengeHeap::heap()->old_gen()->used_in_bytes();
98
99 if (MinHeapFreeRatio != 0) {
100 size_t min_free = calculate_free_based_on_live(live, MinHeapFreeRatio);
101 free_size = MAX2(free_size, min_free);
102 }
103
104 if (MaxHeapFreeRatio != 100) {
105 size_t max_free = calculate_free_based_on_live(live, MaxHeapFreeRatio);
106 free_size = MIN2(max_free, free_size);
107 }
108
109 return free_size;
110 }
111
112 void PSAdaptiveSizePolicy::major_collection_begin() {
113 // Update the interval time
114 _major_timer.stop();
115 // Save most recent collection time
116 _latest_major_mutator_interval_seconds = _major_timer.seconds();
117 _major_timer.reset();
118 _major_timer.start();
119 }
120
121 void PSAdaptiveSizePolicy::update_minor_pause_old_estimator(
122 double minor_pause_in_ms) {
123 double promo_size_in_mbytes = ((double)_promo_size)/((double)M);
124 _minor_pause_old_estimator->update(promo_size_in_mbytes,
125 minor_pause_in_ms);
126 }
127
128 void PSAdaptiveSizePolicy::major_collection_end(size_t amount_live,
129 GCCause::Cause gc_cause) {
130 // Update the pause time.
131 _major_timer.stop();
132
133 if (should_update_promo_stats(gc_cause)) {
134 double major_pause_in_seconds = _major_timer.seconds();
135 double major_pause_in_ms = major_pause_in_seconds * MILLIUNITS;
136
137 // Sample for performance counter
138 _avg_major_pause->sample(major_pause_in_seconds);
139
140 // Cost of collection (unit-less)
141 double collection_cost = 0.0;
142 if ((_latest_major_mutator_interval_seconds > 0.0) &&
143 (major_pause_in_seconds > 0.0)) {
144 double interval_in_seconds =
145 _latest_major_mutator_interval_seconds + major_pause_in_seconds;
146 collection_cost =
147 major_pause_in_seconds / interval_in_seconds;
148 avg_major_gc_cost()->sample(collection_cost);
149
150 // Sample for performance counter
151 _avg_major_interval->sample(interval_in_seconds);
152 }
153
154 // Calculate variables used to estimate pause time vs. gen sizes
155 double eden_size_in_mbytes = ((double)_eden_size)/((double)M);
156 double promo_size_in_mbytes = ((double)_promo_size)/((double)M);
157 _major_pause_old_estimator->update(promo_size_in_mbytes,
158 major_pause_in_ms);
159 _major_pause_young_estimator->update(eden_size_in_mbytes,
160 major_pause_in_ms);
161
162 log_trace(gc, ergo)("psAdaptiveSizePolicy::major_collection_end: major gc cost: %f average: %f",
163 collection_cost,avg_major_gc_cost()->average());
164 log_trace(gc, ergo)(" major pause: %f major period %f",
165 major_pause_in_ms, _latest_major_mutator_interval_seconds * MILLIUNITS);
166
167 // Calculate variable used to estimate collection cost vs. gen sizes
168 assert(collection_cost >= 0.0, "Expected to be non-negative");
169 _major_collection_estimator->update(promo_size_in_mbytes,
170 collection_cost);
171 }
172
173 // Update the amount live at the end of a full GC
174 _live_at_last_full_gc = amount_live;
175
176 // The policy does not have enough data until at least some major collections
177 // have been done.
178 if (_avg_major_pause->count() >= AdaptiveSizePolicyReadyThreshold) {
179 _old_gen_policy_is_ready = true;
180 }
181
182 // Interval times use this timer to measure the interval that
183 // the mutator runs. Reset after the GC pause has been measured.
184 _major_timer.reset();
185 _major_timer.start();
186 }
187
188 // If the remaining free space in the old generation is less that
189 // that expected to be needed by the next collection, do a full
190 // collection now.
191 bool PSAdaptiveSizePolicy::should_full_GC(size_t old_free_in_bytes) {
192
193 // A similar test is done in the scavenge's should_attempt_scavenge(). If
194 // this is changed, decide if that test should also be changed.
195 bool result = padded_average_promoted_in_bytes() > (float) old_free_in_bytes;
196 log_trace(gc, ergo)("%s after scavenge average_promoted " SIZE_FORMAT " padded_average_promoted " SIZE_FORMAT " free in old gen " SIZE_FORMAT,
197 result ? "Full" : "No full",
198 (size_t) average_promoted_in_bytes(),
199 (size_t) padded_average_promoted_in_bytes(),
200 old_free_in_bytes);
201 return result;
202 }
203
204 void PSAdaptiveSizePolicy::clear_generation_free_space_flags() {
205
206 AdaptiveSizePolicy::clear_generation_free_space_flags();
207
208 set_change_old_gen_for_min_pauses(0);
209
210 set_change_young_gen_for_maj_pauses(0);
211 }
212
213 // If this is not a full GC, only test and modify the young generation.
214
215 void PSAdaptiveSizePolicy::compute_generations_free_space(
216 size_t young_live,
217 size_t eden_live,
218 size_t old_live,
219 size_t cur_eden,
220 size_t max_old_gen_size,
221 size_t max_eden_size,
222 bool is_full_gc) {
223 compute_eden_space_size(young_live,
224 eden_live,
225 cur_eden,
226 max_eden_size,
227 is_full_gc);
228
229 compute_old_gen_free_space(old_live,
230 cur_eden,
231 max_old_gen_size,
232 is_full_gc);
233 }
234
235 void PSAdaptiveSizePolicy::compute_eden_space_size(
236 size_t young_live,
237 size_t eden_live,
238 size_t cur_eden,
239 size_t max_eden_size,
240 bool is_full_gc) {
241
242 // Update statistics
243 // Time statistics are updated as we go, update footprint stats here
244 _avg_base_footprint->sample(BaseFootPrintEstimate);
245 avg_young_live()->sample(young_live);
246 avg_eden_live()->sample(eden_live);
247
248 // This code used to return if the policy was not ready , i.e.,
249 // policy_is_ready() returning false. The intent was that
250 // decisions below needed major collection times and so could
251 // not be made before two major collections. A consequence was
252 // adjustments to the young generation were not done until after
253 // two major collections even if the minor collections times
254 // exceeded the requested goals. Now let the young generation
255 // adjust for the minor collection times. Major collection times
256 // will be zero for the first collection and will naturally be
257 // ignored. Tenured generation adjustments are only made at the
258 // full collections so until the second major collection has
259 // been reached, no tenured generation adjustments will be made.
260
261 // Until we know better, desired promotion size uses the last calculation
262 size_t desired_promo_size = _promo_size;
263
264 // Start eden at the current value. The desired value that is stored
265 // in _eden_size is not bounded by constraints of the heap and can
266 // run away.
267 //
268 // As expected setting desired_eden_size to the current
269 // value of desired_eden_size as a starting point
270 // caused desired_eden_size to grow way too large and caused
271 // an overflow down stream. It may have improved performance in
272 // some case but is dangerous.
273 size_t desired_eden_size = cur_eden;
274
275 // Cache some values. There's a bit of work getting these, so
276 // we might save a little time.
277 const double major_cost = major_gc_cost();
278 const double minor_cost = minor_gc_cost();
279
280 // This method sets the desired eden size. That plus the
281 // desired survivor space sizes sets the desired young generation
282 // size. This methods does not know what the desired survivor
283 // size is but expects that other policy will attempt to make
284 // the survivor sizes compatible with the live data in the
285 // young generation. This limit is an estimate of the space left
286 // in the young generation after the survivor spaces have been
287 // subtracted out.
288 size_t eden_limit = max_eden_size;
289
290 const double gc_cost_limit = GCTimeLimit / 100.0;
291
292 // Which way should we go?
293 // if pause requirement is not met
294 // adjust size of any generation with average paus exceeding
295 // the pause limit. Adjust one pause at a time (the larger)
296 // and only make adjustments for the major pause at full collections.
297 // else if throughput requirement not met
298 // adjust the size of the generation with larger gc time. Only
299 // adjust one generation at a time.
300 // else
301 // adjust down the total heap size. Adjust down the larger of the
302 // generations.
303
304 // Add some checks for a threshold for a change. For example,
305 // a change less than the necessary alignment is probably not worth
306 // attempting.
307
308
309 if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) ||
310 (_avg_major_pause->padded_average() > gc_pause_goal_sec())) {
311 //
312 // Check pauses
313 //
314 // Make changes only to affect one of the pauses (the larger)
315 // at a time.
316 adjust_eden_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size);
317
318 } else if (_avg_minor_pause->padded_average() > gc_minor_pause_goal_sec()) {
319 // Adjust only for the minor pause time goal
320 adjust_eden_for_minor_pause_time(is_full_gc, &desired_eden_size);
321
322 } else if(adjusted_mutator_cost() < _throughput_goal) {
323 // This branch used to require that (mutator_cost() > 0.0 in 1.4.2.
324 // This sometimes resulted in skipping to the minimize footprint
325 // code. Change this to try and reduce GC time if mutator time is
326 // negative for whatever reason. Or for future consideration,
327 // bail out of the code if mutator time is negative.
328 //
329 // Throughput
330 //
331 assert(major_cost >= 0.0, "major cost is < 0.0");
332 assert(minor_cost >= 0.0, "minor cost is < 0.0");
333 // Try to reduce the GC times.
334 adjust_eden_for_throughput(is_full_gc, &desired_eden_size);
335
336 } else {
337
338 // Be conservative about reducing the footprint.
339 // Do a minimum number of major collections first.
340 // Have reasonable averages for major and minor collections costs.
341 if (UseAdaptiveSizePolicyFootprintGoal &&
342 young_gen_policy_is_ready() &&
343 avg_major_gc_cost()->average() >= 0.0 &&
344 avg_minor_gc_cost()->average() >= 0.0) {
345 size_t desired_sum = desired_eden_size + desired_promo_size;
346 desired_eden_size = adjust_eden_for_footprint(desired_eden_size, desired_sum);
347 }
348 }
349
350 // Note we make the same tests as in the code block below; the code
351 // seems a little easier to read with the printing in another block.
352 if (desired_eden_size > eden_limit) {
353 log_debug(gc, ergo)(
354 "PSAdaptiveSizePolicy::compute_eden_space_size limits:"
355 " desired_eden_size: " SIZE_FORMAT
356 " old_eden_size: " SIZE_FORMAT
357 " eden_limit: " SIZE_FORMAT
358 " cur_eden: " SIZE_FORMAT
359 " max_eden_size: " SIZE_FORMAT
360 " avg_young_live: " SIZE_FORMAT,
361 desired_eden_size, _eden_size, eden_limit, cur_eden,
362 max_eden_size, (size_t)avg_young_live()->average());
363 }
364 if (gc_cost() > gc_cost_limit) {
365 log_debug(gc, ergo)(
366 "PSAdaptiveSizePolicy::compute_eden_space_size: gc time limit"
367 " gc_cost: %f "
368 " GCTimeLimit: " UINTX_FORMAT,
369 gc_cost(), GCTimeLimit);
370 }
371
372 // Align everything and make a final limit check
373 desired_eden_size = align_up(desired_eden_size, _space_alignment);
374 desired_eden_size = MAX2(desired_eden_size, _space_alignment);
375
376 eden_limit = align_down(eden_limit, _space_alignment);
377
378 // And one last limit check, now that we've aligned things.
379 if (desired_eden_size > eden_limit) {
380 // If the policy says to get a larger eden but
381 // is hitting the limit, don't decrease eden.
382 // This can lead to a general drifting down of the
383 // eden size. Let the tenuring calculation push more
384 // into the old gen.
385 desired_eden_size = MAX2(eden_limit, cur_eden);
386 }
387
388 log_debug(gc, ergo)("PSAdaptiveSizePolicy::compute_eden_space_size: costs minor_time: %f major_cost: %f mutator_cost: %f throughput_goal: %f",
389 minor_gc_cost(), major_gc_cost(), mutator_cost(), _throughput_goal);
390
391 log_trace(gc, ergo)("Minor_pause: %f major_pause: %f minor_interval: %f major_interval: %fpause_goal: %f",
392 _avg_minor_pause->padded_average(),
393 _avg_major_pause->padded_average(),
394 _avg_minor_interval->average(),
395 _avg_major_interval->average(),
396 gc_pause_goal_sec());
397
398 log_debug(gc, ergo)("Live_space: " SIZE_FORMAT " free_space: " SIZE_FORMAT,
399 live_space(), free_space());
400
401 log_trace(gc, ergo)("Base_footprint: " SIZE_FORMAT " avg_young_live: " SIZE_FORMAT " avg_old_live: " SIZE_FORMAT,
402 (size_t)_avg_base_footprint->average(),
403 (size_t)avg_young_live()->average(),
404 (size_t)avg_old_live()->average());
405
406 log_debug(gc, ergo)("Old eden_size: " SIZE_FORMAT " desired_eden_size: " SIZE_FORMAT,
407 _eden_size, desired_eden_size);
408
409 set_eden_size(desired_eden_size);
410 }
411
412 void PSAdaptiveSizePolicy::compute_old_gen_free_space(
413 size_t old_live,
414 size_t cur_eden,
415 size_t max_old_gen_size,
416 bool is_full_gc) {
417
418 // Update statistics
419 // Time statistics are updated as we go, update footprint stats here
420 if (is_full_gc) {
421 // old_live is only accurate after a full gc
422 avg_old_live()->sample(old_live);
423 }
424
425 // This code used to return if the policy was not ready , i.e.,
426 // policy_is_ready() returning false. The intent was that
427 // decisions below needed major collection times and so could
428 // not be made before two major collections. A consequence was
429 // adjustments to the young generation were not done until after
430 // two major collections even if the minor collections times
431 // exceeded the requested goals. Now let the young generation
432 // adjust for the minor collection times. Major collection times
433 // will be zero for the first collection and will naturally be
434 // ignored. Tenured generation adjustments are only made at the
435 // full collections so until the second major collection has
436 // been reached, no tenured generation adjustments will be made.
437
438 // Until we know better, desired promotion size uses the last calculation
439 size_t desired_promo_size = _promo_size;
440
441 // Start eden at the current value. The desired value that is stored
442 // in _eden_size is not bounded by constraints of the heap and can
443 // run away.
444 //
445 // As expected setting desired_eden_size to the current
446 // value of desired_eden_size as a starting point
447 // caused desired_eden_size to grow way too large and caused
448 // an overflow down stream. It may have improved performance in
449 // some case but is dangerous.
450 size_t desired_eden_size = cur_eden;
451
452 // Cache some values. There's a bit of work getting these, so
453 // we might save a little time.
454 const double major_cost = major_gc_cost();
455 const double minor_cost = minor_gc_cost();
456
457 // Limits on our growth
458 size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average());
459
460 // But don't force a promo size below the current promo size. Otherwise,
461 // the promo size will shrink for no good reason.
462 promo_limit = MAX2(promo_limit, _promo_size);
463
464 const double gc_cost_limit = GCTimeLimit/100.0;
465
466 // Which way should we go?
467 // if pause requirement is not met
468 // adjust size of any generation with average paus exceeding
469 // the pause limit. Adjust one pause at a time (the larger)
470 // and only make adjustments for the major pause at full collections.
471 // else if throughput requirement not met
472 // adjust the size of the generation with larger gc time. Only
473 // adjust one generation at a time.
474 // else
475 // adjust down the total heap size. Adjust down the larger of the
476 // generations.
477
478 // Add some checks for a threshold for a change. For example,
479 // a change less than the necessary alignment is probably not worth
480 // attempting.
481
482 if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) ||
483 (_avg_major_pause->padded_average() > gc_pause_goal_sec())) {
484 //
485 // Check pauses
486 //
487 // Make changes only to affect one of the pauses (the larger)
488 // at a time.
489 if (is_full_gc) {
490 set_decide_at_full_gc(decide_at_full_gc_true);
491 adjust_promo_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size);
492 }
493 } else if (adjusted_mutator_cost() < _throughput_goal) {
494 // This branch used to require that (mutator_cost() > 0.0 in 1.4.2.
495 // This sometimes resulted in skipping to the minimize footprint
496 // code. Change this to try and reduce GC time if mutator time is
497 // negative for whatever reason. Or for future consideration,
498 // bail out of the code if mutator time is negative.
499 //
500 // Throughput
501 //
502 assert(major_cost >= 0.0, "major cost is < 0.0");
503 assert(minor_cost >= 0.0, "minor cost is < 0.0");
504 // Try to reduce the GC times.
505 if (is_full_gc) {
506 set_decide_at_full_gc(decide_at_full_gc_true);
507 adjust_promo_for_throughput(is_full_gc, &desired_promo_size);
508 }
509 } else {
510
511 // Be conservative about reducing the footprint.
512 // Do a minimum number of major collections first.
513 // Have reasonable averages for major and minor collections costs.
514 if (UseAdaptiveSizePolicyFootprintGoal &&
515 young_gen_policy_is_ready() &&
516 avg_major_gc_cost()->average() >= 0.0 &&
517 avg_minor_gc_cost()->average() >= 0.0) {
518 if (is_full_gc) {
519 set_decide_at_full_gc(decide_at_full_gc_true);
520 size_t desired_sum = desired_eden_size + desired_promo_size;
521 desired_promo_size = adjust_promo_for_footprint(desired_promo_size, desired_sum);
522 }
523 }
524 }
525
526 // Note we make the same tests as in the code block below; the code
527 // seems a little easier to read with the printing in another block.
528 if (desired_promo_size > promo_limit) {
529 // "free_in_old_gen" was the original value for used for promo_limit
530 size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
531 log_debug(gc, ergo)(
532 "PSAdaptiveSizePolicy::compute_old_gen_free_space limits:"
533 " desired_promo_size: " SIZE_FORMAT
534 " promo_limit: " SIZE_FORMAT
535 " free_in_old_gen: " SIZE_FORMAT
536 " max_old_gen_size: " SIZE_FORMAT
537 " avg_old_live: " SIZE_FORMAT,
538 desired_promo_size, promo_limit, free_in_old_gen,
539 max_old_gen_size, (size_t) avg_old_live()->average());
540 }
541 if (gc_cost() > gc_cost_limit) {
542 log_debug(gc, ergo)(
543 "PSAdaptiveSizePolicy::compute_old_gen_free_space: gc time limit"
544 " gc_cost: %f "
545 " GCTimeLimit: " UINTX_FORMAT,
546 gc_cost(), GCTimeLimit);
547 }
548
549 // Align everything and make a final limit check
550 desired_promo_size = align_up(desired_promo_size, _space_alignment);
551 desired_promo_size = MAX2(desired_promo_size, _space_alignment);
552
553 promo_limit = align_down(promo_limit, _space_alignment);
554
555 // And one last limit check, now that we've aligned things.
556 desired_promo_size = MIN2(desired_promo_size, promo_limit);
557
558 // Timing stats
559 log_debug(gc, ergo)("PSAdaptiveSizePolicy::compute_old_gen_free_space: costs minor_time: %f major_cost: %f mutator_cost: %f throughput_goal: %f",
560 minor_gc_cost(), major_gc_cost(), mutator_cost(), _throughput_goal);
561
562 log_trace(gc, ergo)("Minor_pause: %f major_pause: %f minor_interval: %f major_interval: %f pause_goal: %f",
563 _avg_minor_pause->padded_average(),
564 _avg_major_pause->padded_average(),
565 _avg_minor_interval->average(),
566 _avg_major_interval->average(),
567 gc_pause_goal_sec());
568
569 // Footprint stats
570 log_debug(gc, ergo)("Live_space: " SIZE_FORMAT " free_space: " SIZE_FORMAT,
571 live_space(), free_space());
572
573 log_trace(gc, ergo)("Base_footprint: " SIZE_FORMAT " avg_young_live: " SIZE_FORMAT " avg_old_live: " SIZE_FORMAT,
574 (size_t)_avg_base_footprint->average(),
575 (size_t)avg_young_live()->average(),
576 (size_t)avg_old_live()->average());
577
578 log_debug(gc, ergo)("Old promo_size: " SIZE_FORMAT " desired_promo_size: " SIZE_FORMAT,
579 _promo_size, desired_promo_size);
580
581 set_promo_size(desired_promo_size);
582 }
583
584 void PSAdaptiveSizePolicy::decay_supplemental_growth(bool is_full_gc) {
585 // Decay the supplemental increment? Decay the supplement growth
586 // factor even if it is not used. It is only meant to give a boost
587 // to the initial growth and if it is not used, then it was not
588 // needed.
589 if (is_full_gc) {
590 // Don't wait for the threshold value for the major collections. If
591 // here, the supplemental growth term was used and should decay.
592 if ((_avg_major_pause->count() % TenuredGenerationSizeSupplementDecay)
593 == 0) {
594 _old_gen_size_increment_supplement =
595 _old_gen_size_increment_supplement >> 1;
596 }
597 } else {
598 if ((_avg_minor_pause->count() >= AdaptiveSizePolicyReadyThreshold) &&
599 (_avg_minor_pause->count() % YoungGenerationSizeSupplementDecay) == 0) {
600 _young_gen_size_increment_supplement =
601 _young_gen_size_increment_supplement >> 1;
602 }
603 }
604 }
605
606 void PSAdaptiveSizePolicy::adjust_eden_for_minor_pause_time(bool is_full_gc,
607 size_t* desired_eden_size_ptr) {
608
609 // Adjust the young generation size to reduce pause time of
610 // of collections.
611 //
612 // The AdaptiveSizePolicyInitializingSteps test is not used
613 // here. It has not seemed to be needed but perhaps should
614 // be added for consistency.
615 if (minor_pause_young_estimator()->decrement_will_decrease()) {
616 // reduce eden size
617 set_change_young_gen_for_min_pauses(
618 decrease_young_gen_for_min_pauses_true);
619 *desired_eden_size_ptr = *desired_eden_size_ptr -
620 eden_decrement_aligned_down(*desired_eden_size_ptr);
621 } else {
622 // EXPERIMENTAL ADJUSTMENT
623 // Only record that the estimator indicated such an action.
624 // *desired_eden_size_ptr = *desired_eden_size_ptr + eden_heap_delta;
625 set_change_young_gen_for_min_pauses(
626 increase_young_gen_for_min_pauses_true);
627 }
628 }
629
630 void PSAdaptiveSizePolicy::adjust_promo_for_pause_time(bool is_full_gc,
631 size_t* desired_promo_size_ptr,
632 size_t* desired_eden_size_ptr) {
633
634 size_t promo_heap_delta = 0;
635 // Add some checks for a threshold for a change. For example,
636 // a change less than the required alignment is probably not worth
637 // attempting.
638
639 if (_avg_minor_pause->padded_average() <= _avg_major_pause->padded_average() && is_full_gc) {
640 // Adjust for the major pause time only at full gc's because the
641 // affects of a change can only be seen at full gc's.
642
643 // Reduce old generation size to reduce pause?
644 if (major_pause_old_estimator()->decrement_will_decrease()) {
645 // reduce old generation size
646 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true);
647 promo_heap_delta = promo_decrement_aligned_down(*desired_promo_size_ptr);
648 *desired_promo_size_ptr = _promo_size - promo_heap_delta;
649 } else {
650 // EXPERIMENTAL ADJUSTMENT
651 // Only record that the estimator indicated such an action.
652 // *desired_promo_size_ptr = _promo_size +
653 // promo_increment_aligned_up(*desired_promo_size_ptr);
654 set_change_old_gen_for_maj_pauses(increase_old_gen_for_maj_pauses_true);
655 }
656 }
657
658 log_trace(gc, ergo)(
659 "PSAdaptiveSizePolicy::adjust_promo_for_pause_time "
660 "adjusting gen sizes for major pause (avg %f goal %f). "
661 "desired_promo_size " SIZE_FORMAT " promo delta " SIZE_FORMAT,
662 _avg_major_pause->average(), gc_pause_goal_sec(),
663 *desired_promo_size_ptr, promo_heap_delta);
664 }
665
666 void PSAdaptiveSizePolicy::adjust_eden_for_pause_time(bool is_full_gc,
667 size_t* desired_promo_size_ptr,
668 size_t* desired_eden_size_ptr) {
669
670 size_t eden_heap_delta = 0;
671 // Add some checks for a threshold for a change. For example,
672 // a change less than the required alignment is probably not worth
673 // attempting.
674 if (_avg_minor_pause->padded_average() > _avg_major_pause->padded_average()) {
675 adjust_eden_for_minor_pause_time(is_full_gc, desired_eden_size_ptr);
676 }
677 log_trace(gc, ergo)(
678 "PSAdaptiveSizePolicy::adjust_eden_for_pause_time "
679 "adjusting gen sizes for major pause (avg %f goal %f). "
680 "desired_eden_size " SIZE_FORMAT " eden delta " SIZE_FORMAT,
681 _avg_major_pause->average(), gc_pause_goal_sec(),
682 *desired_eden_size_ptr, eden_heap_delta);
683 }
684
685 void PSAdaptiveSizePolicy::adjust_promo_for_throughput(bool is_full_gc,
686 size_t* desired_promo_size_ptr) {
687
688 // Add some checks for a threshold for a change. For example,
689 // a change less than the required alignment is probably not worth
690 // attempting.
691
692 if ((gc_cost() + mutator_cost()) == 0.0) {
693 return;
694 }
695
696 log_trace(gc, ergo)("PSAdaptiveSizePolicy::adjust_promo_for_throughput(is_full: %d, promo: " SIZE_FORMAT "): mutator_cost %f major_gc_cost %f minor_gc_cost %f",
697 is_full_gc, *desired_promo_size_ptr, mutator_cost(), major_gc_cost(), minor_gc_cost());
698
699 // Tenured generation
700 if (is_full_gc) {
701 // Calculate the change to use for the tenured gen.
702 size_t scaled_promo_heap_delta = 0;
703 // Can the increment to the generation be scaled?
704 if (gc_cost() >= 0.0 && major_gc_cost() >= 0.0) {
705 size_t promo_heap_delta =
706 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
707 double scale_by_ratio = major_gc_cost() / gc_cost();
708 scaled_promo_heap_delta =
709 (size_t) (scale_by_ratio * (double) promo_heap_delta);
710 log_trace(gc, ergo)("Scaled tenured increment: " SIZE_FORMAT " by %f down to " SIZE_FORMAT,
711 promo_heap_delta, scale_by_ratio, scaled_promo_heap_delta);
712 } else if (major_gc_cost() >= 0.0) {
713 // Scaling is not going to work. If the major gc time is the
714 // larger, give it a full increment.
715 if (major_gc_cost() >= minor_gc_cost()) {
716 scaled_promo_heap_delta =
717 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
718 }
719 } else {
720 // Don't expect to get here but it's ok if it does
721 // in the product build since the delta will be 0
722 // and nothing will change.
723 assert(false, "Unexpected value for gc costs");
724 }
725
726 switch (AdaptiveSizeThroughPutPolicy) {
727 case 1:
728 // Early in the run the statistics might not be good. Until
729 // a specific number of collections have been, use the heuristic
730 // that a larger generation size means lower collection costs.
731 if (major_collection_estimator()->increment_will_decrease() ||
732 (_old_gen_change_for_major_throughput
733 <= AdaptiveSizePolicyInitializingSteps)) {
734 // Increase tenured generation size to reduce major collection cost
735 if ((*desired_promo_size_ptr + scaled_promo_heap_delta) >
736 *desired_promo_size_ptr) {
737 *desired_promo_size_ptr = _promo_size + scaled_promo_heap_delta;
738 }
739 set_change_old_gen_for_throughput(
740 increase_old_gen_for_throughput_true);
741 _old_gen_change_for_major_throughput++;
742 } else {
743 // EXPERIMENTAL ADJUSTMENT
744 // Record that decreasing the old gen size would decrease
745 // the major collection cost but don't do it.
746 // *desired_promo_size_ptr = _promo_size -
747 // promo_decrement_aligned_down(*desired_promo_size_ptr);
748 set_change_old_gen_for_throughput(
749 decrease_old_gen_for_throughput_true);
750 }
751
752 break;
753 default:
754 // Simplest strategy
755 if ((*desired_promo_size_ptr + scaled_promo_heap_delta) >
756 *desired_promo_size_ptr) {
757 *desired_promo_size_ptr = *desired_promo_size_ptr +
758 scaled_promo_heap_delta;
759 }
760 set_change_old_gen_for_throughput(
761 increase_old_gen_for_throughput_true);
762 _old_gen_change_for_major_throughput++;
763 }
764
765 log_trace(gc, ergo)("Adjusting tenured gen for throughput (avg %f goal %f). desired_promo_size " SIZE_FORMAT " promo_delta " SIZE_FORMAT ,
766 mutator_cost(),
767 _throughput_goal,
768 *desired_promo_size_ptr, scaled_promo_heap_delta);
769 }
770 }
771
772 void PSAdaptiveSizePolicy::adjust_eden_for_throughput(bool is_full_gc,
773 size_t* desired_eden_size_ptr) {
774
775 // Add some checks for a threshold for a change. For example,
776 // a change less than the required alignment is probably not worth
777 // attempting.
778
779 if ((gc_cost() + mutator_cost()) == 0.0) {
780 return;
781 }
782
783 log_trace(gc, ergo)("PSAdaptiveSizePolicy::adjust_eden_for_throughput(is_full: %d, cur_eden: " SIZE_FORMAT "): mutator_cost %f major_gc_cost %f minor_gc_cost %f",
784 is_full_gc, *desired_eden_size_ptr, mutator_cost(), major_gc_cost(), minor_gc_cost());
785
786 // Young generation
787 size_t scaled_eden_heap_delta = 0;
788 // Can the increment to the generation be scaled?
789 if (gc_cost() >= 0.0 && minor_gc_cost() >= 0.0) {
790 size_t eden_heap_delta =
791 eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr);
792 double scale_by_ratio = minor_gc_cost() / gc_cost();
793 assert(scale_by_ratio <= 1.0 && scale_by_ratio >= 0.0, "Scaling is wrong");
794 scaled_eden_heap_delta =
795 (size_t) (scale_by_ratio * (double) eden_heap_delta);
796 log_trace(gc, ergo)("Scaled eden increment: " SIZE_FORMAT " by %f down to " SIZE_FORMAT,
797 eden_heap_delta, scale_by_ratio, scaled_eden_heap_delta);
798 } else if (minor_gc_cost() >= 0.0) {
799 // Scaling is not going to work. If the minor gc time is the
800 // larger, give it a full increment.
801 if (minor_gc_cost() > major_gc_cost()) {
802 scaled_eden_heap_delta =
803 eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr);
804 }
805 } else {
806 // Don't expect to get here but it's ok if it does
807 // in the product build since the delta will be 0
808 // and nothing will change.
809 assert(false, "Unexpected value for gc costs");
810 }
811
812 // Use a heuristic for some number of collections to give
813 // the averages time to settle down.
814 switch (AdaptiveSizeThroughPutPolicy) {
815 case 1:
816 if (minor_collection_estimator()->increment_will_decrease() ||
817 (_young_gen_change_for_minor_throughput
818 <= AdaptiveSizePolicyInitializingSteps)) {
819 // Expand young generation size to reduce frequency of
820 // of collections.
821 if ((*desired_eden_size_ptr + scaled_eden_heap_delta) >
822 *desired_eden_size_ptr) {
823 *desired_eden_size_ptr =
824 *desired_eden_size_ptr + scaled_eden_heap_delta;
825 }
826 set_change_young_gen_for_throughput(
827 increase_young_gen_for_througput_true);
828 _young_gen_change_for_minor_throughput++;
829 } else {
830 // EXPERIMENTAL ADJUSTMENT
831 // Record that decreasing the young gen size would decrease
832 // the minor collection cost but don't do it.
833 // *desired_eden_size_ptr = _eden_size -
834 // eden_decrement_aligned_down(*desired_eden_size_ptr);
835 set_change_young_gen_for_throughput(
836 decrease_young_gen_for_througput_true);
837 }
838 break;
839 default:
840 if ((*desired_eden_size_ptr + scaled_eden_heap_delta) >
841 *desired_eden_size_ptr) {
842 *desired_eden_size_ptr =
843 *desired_eden_size_ptr + scaled_eden_heap_delta;
844 }
845 set_change_young_gen_for_throughput(
846 increase_young_gen_for_througput_true);
847 _young_gen_change_for_minor_throughput++;
848 }
849
850 log_trace(gc, ergo)("Adjusting eden for throughput (avg %f goal %f). desired_eden_size " SIZE_FORMAT " eden delta " SIZE_FORMAT,
851 mutator_cost(), _throughput_goal, *desired_eden_size_ptr, scaled_eden_heap_delta);
852 }
853
854 size_t PSAdaptiveSizePolicy::adjust_promo_for_footprint(
855 size_t desired_promo_size, size_t desired_sum) {
856 assert(desired_promo_size <= desired_sum, "Inconsistent parameters");
857 set_decrease_for_footprint(decrease_old_gen_for_footprint_true);
858
859 size_t change = promo_decrement(desired_promo_size);
860 change = scale_down(change, desired_promo_size, desired_sum);
861
862 size_t reduced_size = desired_promo_size - change;
863
864 log_trace(gc, ergo)(
865 "AdaptiveSizePolicy::adjust_promo_for_footprint "
866 "adjusting tenured gen for footprint. "
867 "starting promo size " SIZE_FORMAT
868 " reduced promo size " SIZE_FORMAT
869 " promo delta " SIZE_FORMAT,
870 desired_promo_size, reduced_size, change );
871
872 assert(reduced_size <= desired_promo_size, "Inconsistent result");
873 return reduced_size;
874 }
875
876 size_t PSAdaptiveSizePolicy::adjust_eden_for_footprint(
877 size_t desired_eden_size, size_t desired_sum) {
878 assert(desired_eden_size <= desired_sum, "Inconsistent parameters");
879 set_decrease_for_footprint(decrease_young_gen_for_footprint_true);
880
881 size_t change = eden_decrement(desired_eden_size);
882 change = scale_down(change, desired_eden_size, desired_sum);
883
884 size_t reduced_size = desired_eden_size - change;
885
886 log_trace(gc, ergo)(
887 "AdaptiveSizePolicy::adjust_eden_for_footprint "
888 "adjusting eden for footprint. "
889 " starting eden size " SIZE_FORMAT
890 " reduced eden size " SIZE_FORMAT
891 " eden delta " SIZE_FORMAT,
892 desired_eden_size, reduced_size, change);
893
894 assert(reduced_size <= desired_eden_size, "Inconsistent result");
895 return reduced_size;
896 }
897
898 // Scale down "change" by the factor
899 // part / total
900 // Don't align the results.
901
902 size_t PSAdaptiveSizePolicy::scale_down(size_t change,
903 double part,
904 double total) {
905 assert(part <= total, "Inconsistent input");
906 size_t reduced_change = change;
907 if (total > 0) {
908 double fraction = part / total;
909 reduced_change = (size_t) (fraction * (double) change);
910 }
911 assert(reduced_change <= change, "Inconsistent result");
912 return reduced_change;
913 }
914
915 size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden,
916 uint percent_change) {
917 size_t eden_heap_delta;
918 eden_heap_delta = cur_eden / 100 * percent_change;
919 return eden_heap_delta;
920 }
921
922 size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden) {
923 return eden_increment(cur_eden, YoungGenerationSizeIncrement);
924 }
925
926 size_t PSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) {
927 size_t result = eden_increment(cur_eden, YoungGenerationSizeIncrement);
928 return align_up(result, _space_alignment);
929 }
930
931 size_t PSAdaptiveSizePolicy::eden_increment_aligned_down(size_t cur_eden) {
932 size_t result = eden_increment(cur_eden);
933 return align_down(result, _space_alignment);
934 }
935
936 size_t PSAdaptiveSizePolicy::eden_increment_with_supplement_aligned_up(
937 size_t cur_eden) {
938 size_t result = eden_increment(cur_eden,
939 YoungGenerationSizeIncrement + _young_gen_size_increment_supplement);
940 return align_up(result, _space_alignment);
941 }
942
943 size_t PSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) {
944 size_t eden_heap_delta = eden_decrement(cur_eden);
945 return align_down(eden_heap_delta, _space_alignment);
946 }
947
948 size_t PSAdaptiveSizePolicy::eden_decrement(size_t cur_eden) {
949 size_t eden_heap_delta = eden_increment(cur_eden) /
950 AdaptiveSizeDecrementScaleFactor;
951 return eden_heap_delta;
952 }
953
954 size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo,
955 uint percent_change) {
956 size_t promo_heap_delta;
957 promo_heap_delta = cur_promo / 100 * percent_change;
958 return promo_heap_delta;
959 }
960
961 size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo) {
962 return promo_increment(cur_promo, TenuredGenerationSizeIncrement);
963 }
964
965 size_t PSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) {
966 size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement);
967 return align_up(result, _space_alignment);
968 }
969
970 size_t PSAdaptiveSizePolicy::promo_increment_aligned_down(size_t cur_promo) {
971 size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement);
972 return align_down(result, _space_alignment);
973 }
974
975 size_t PSAdaptiveSizePolicy::promo_increment_with_supplement_aligned_up(
976 size_t cur_promo) {
977 size_t result = promo_increment(cur_promo,
978 TenuredGenerationSizeIncrement + _old_gen_size_increment_supplement);
979 return align_up(result, _space_alignment);
980 }
981
982 size_t PSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) {
983 size_t promo_heap_delta = promo_decrement(cur_promo);
984 return align_down(promo_heap_delta, _space_alignment);
985 }
986
987 size_t PSAdaptiveSizePolicy::promo_decrement(size_t cur_promo) {
988 size_t promo_heap_delta = promo_increment(cur_promo);
989 promo_heap_delta = promo_heap_delta / AdaptiveSizeDecrementScaleFactor;
990 return promo_heap_delta;
991 }
992
993 uint PSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold(
994 bool is_survivor_overflow,
995 uint tenuring_threshold,
996 size_t survivor_limit) {
997 assert(survivor_limit >= _space_alignment,
998 "survivor_limit too small");
999 assert(is_aligned(survivor_limit, _space_alignment),
1000 "survivor_limit not aligned");
1001
1002 // This method is called even if the tenuring threshold and survivor
1003 // spaces are not adjusted so that the averages are sampled above.
1004 if (!UsePSAdaptiveSurvivorSizePolicy ||
1005 !young_gen_policy_is_ready()) {
1006 return tenuring_threshold;
1007 }
1008
1009 // We'll decide whether to increase or decrease the tenuring
1010 // threshold based partly on the newly computed survivor size
1011 // (if we hit the maximum limit allowed, we'll always choose to
1012 // decrement the threshold).
1013 bool incr_tenuring_threshold = false;
1014 bool decr_tenuring_threshold = false;
1015
1016 set_decrement_tenuring_threshold_for_gc_cost(false);
1017 set_increment_tenuring_threshold_for_gc_cost(false);
1018 set_decrement_tenuring_threshold_for_survivor_limit(false);
1019
1020 if (!is_survivor_overflow) {
1021 // Keep running averages on how much survived
1022
1023 // We use the tenuring threshold to equalize the cost of major
1024 // and minor collections.
1025 // ThresholdTolerance is used to indicate how sensitive the
1026 // tenuring threshold is to differences in cost between the
1027 // collection types.
1028
1029 // Get the times of interest. This involves a little work, so
1030 // we cache the values here.
1031 const double major_cost = major_gc_cost();
1032 const double minor_cost = minor_gc_cost();
1033
1034 if (minor_cost > major_cost * _threshold_tolerance_percent) {
1035 // Minor times are getting too long; lower the threshold so
1036 // less survives and more is promoted.
1037 decr_tenuring_threshold = true;
1038 set_decrement_tenuring_threshold_for_gc_cost(true);
1039 } else if (major_cost > minor_cost * _threshold_tolerance_percent) {
1040 // Major times are too long, so we want less promotion.
1041 incr_tenuring_threshold = true;
1042 set_increment_tenuring_threshold_for_gc_cost(true);
1043 }
1044
1045 } else {
1046 // Survivor space overflow occurred, so promoted and survived are
1047 // not accurate. We'll make our best guess by combining survived
1048 // and promoted and count them as survivors.
1049 //
1050 // We'll lower the tenuring threshold to see if we can correct
1051 // things. Also, set the survivor size conservatively. We're
1052 // trying to avoid many overflows from occurring if defnew size
1053 // is just too small.
1054
1055 decr_tenuring_threshold = true;
1056 }
1057
1058 // The padded average also maintains a deviation from the average;
1059 // we use this to see how good of an estimate we have of what survived.
1060 // We're trying to pad the survivor size as little as possible without
1061 // overflowing the survivor spaces.
1062 size_t target_size = align_up((size_t)_avg_survived->padded_average(),
1063 _space_alignment);
1064 target_size = MAX2(target_size, _space_alignment);
1065
1066 if (target_size > survivor_limit) {
1067 // Target size is bigger than we can handle. Let's also reduce
1068 // the tenuring threshold.
1069 target_size = survivor_limit;
1070 decr_tenuring_threshold = true;
1071 set_decrement_tenuring_threshold_for_survivor_limit(true);
1072 }
1073
1074 // Finally, increment or decrement the tenuring threshold, as decided above.
1075 // We test for decrementing first, as we might have hit the target size
1076 // limit.
1077 if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1078 if (tenuring_threshold > 1) {
1079 tenuring_threshold--;
1080 }
1081 } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1082 if (tenuring_threshold < MaxTenuringThreshold) {
1083 tenuring_threshold++;
1084 }
1085 }
1086
1087 // We keep a running average of the amount promoted which is used
1088 // to decide when we should collect the old generation (when
1089 // the amount of old gen free space is less than what we expect to
1090 // promote).
1091
1092 log_trace(gc, ergo)("avg_survived: %f avg_deviation: %f", _avg_survived->average(), _avg_survived->deviation());
1093 log_debug(gc, ergo)("avg_survived_padded_avg: %f", _avg_survived->padded_average());
1094
1095 log_trace(gc, ergo)("avg_promoted_avg: %f avg_promoted_dev: %f", avg_promoted()->average(), avg_promoted()->deviation());
1096 log_debug(gc, ergo)("avg_promoted_padded_avg: %f avg_pretenured_padded_avg: %f tenuring_thresh: %d target_size: " SIZE_FORMAT,
1097 avg_promoted()->padded_average(),
1098 _avg_pretenured->padded_average(),
1099 tenuring_threshold, target_size);
1100
1101 set_survivor_size(target_size);
1102
1103 return tenuring_threshold;
1104 }
1105
1106 void PSAdaptiveSizePolicy::update_averages(bool is_survivor_overflow,
1107 size_t survived,
1108 size_t promoted) {
1109 // Update averages
1110 if (!is_survivor_overflow) {
1111 // Keep running averages on how much survived
1112 _avg_survived->sample(survived);
1113 } else {
1114 size_t survived_guess = survived + promoted;
1115 _avg_survived->sample(survived_guess);
1116 }
1117 avg_promoted()->sample(promoted);
1118
1119 log_trace(gc, ergo)("AdaptiveSizePolicy::update_averages: survived: " SIZE_FORMAT " promoted: " SIZE_FORMAT " overflow: %s",
1120 survived, promoted, is_survivor_overflow ? "true" : "false");
1121 }
1122
1123 bool PSAdaptiveSizePolicy::print() const {
1124
1125 if (!UseAdaptiveSizePolicy) {
1126 return false;
1127 }
1128
1129 if (AdaptiveSizePolicy::print()) {
1130 AdaptiveSizePolicy::print_tenuring_threshold(PSScavenge::tenuring_threshold());
1131 return true;
1132 }
1133
1134 return false;
1135 }