1 /*
2 * Copyright (c) 2002, 2019, 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.
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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
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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/gcUtil.inline.hpp"
33 #include "gc/shared/gcPolicyCounters.hpp"
34 #include "logging/log.hpp"
35 #include "runtime/timer.hpp"
36 #include "utilities/align.hpp"
37
38 #include <math.h>
39
40 PSAdaptiveSizePolicy::PSAdaptiveSizePolicy(size_t init_eden_size,
41 size_t init_promo_size,
42 size_t init_survivor_size,
43 size_t space_alignment,
44 double gc_pause_goal_sec,
45 double gc_minor_pause_goal_sec,
46 uint gc_cost_ratio) :
47 AdaptiveSizePolicy(init_eden_size,
48 init_promo_size,
49 init_survivor_size,
50 gc_pause_goal_sec,
51 gc_cost_ratio),
52 _avg_major_pause(new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding)),
53 _avg_base_footprint(new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight)),
54 _gc_stats(),
55 _collection_cost_margin_fraction(AdaptiveSizePolicyCollectionCostMargin / 100.0),
56 _major_pause_old_estimator(new LinearLeastSquareFit(AdaptiveSizePolicyWeight)),
57 _major_pause_young_estimator(new LinearLeastSquareFit(AdaptiveSizePolicyWeight)),
58 _latest_major_mutator_interval_seconds(0),
59 _space_alignment(space_alignment),
60 _gc_minor_pause_goal_sec(gc_minor_pause_goal_sec),
61 _live_at_last_full_gc(init_promo_size),
62 _change_old_gen_for_min_pauses(0),
63 _change_young_gen_for_maj_pauses(0),
64 _old_gen_policy_is_ready(false),
65 _young_gen_size_increment_supplement(YoungGenerationSizeSupplement),
66 _old_gen_size_increment_supplement(TenuredGenerationSizeSupplement),
67 _bytes_absorbed_from_eden(0)
68 {
69 // Start the timers
70 _major_timer.start();
71 }
72
73 size_t PSAdaptiveSizePolicy::calculate_free_based_on_live(size_t live, uintx ratio_as_percentage) {
74 // We want to calculate how much free memory there can be based on the
75 // amount of live data currently in the old gen. Using the formula:
76 // ratio * (free + live) = free
77 // Some equation solving later we get:
78 // free = (live * ratio) / (1 - ratio)
79
80 const double ratio = ratio_as_percentage / 100.0;
81 const double ratio_inverse = 1.0 - ratio;
82 const double tmp = live * ratio;
83 size_t free = (size_t)(tmp / ratio_inverse);
84
85 return free;
86 }
87
88 size_t PSAdaptiveSizePolicy::calculated_old_free_size_in_bytes() const {
89 size_t free_size = (size_t)(_promo_size + avg_promoted()->padded_average());
90 size_t live = ParallelScavengeHeap::heap()->old_gen()->used_in_bytes();
91
92 if (MinHeapFreeRatio != 0) {
93 size_t min_free = calculate_free_based_on_live(live, MinHeapFreeRatio);
94 free_size = MAX2(free_size, min_free);
95 }
96
97 if (MaxHeapFreeRatio != 100) {
98 size_t max_free = calculate_free_based_on_live(live, MaxHeapFreeRatio);
99 free_size = MIN2(max_free, free_size);
100 }
101
102 return free_size;
103 }
104
105 void PSAdaptiveSizePolicy::major_collection_begin() {
106 // Update the interval time
107 _major_timer.stop();
108 // Save most recent collection time
109 _latest_major_mutator_interval_seconds = _major_timer.seconds();
110 _major_timer.reset();
111 _major_timer.start();
112 }
113
114 void PSAdaptiveSizePolicy::update_minor_pause_old_estimator(
115 double minor_pause_in_ms) {
116 double promo_size_in_mbytes = ((double)_promo_size)/((double)M);
117 _minor_pause_old_estimator->update(promo_size_in_mbytes,
118 minor_pause_in_ms);
119 }
120
121 void PSAdaptiveSizePolicy::major_collection_end(size_t amount_live,
122 GCCause::Cause gc_cause) {
123 // Update the pause time.
124 _major_timer.stop();
125
126 if (should_update_promo_stats(gc_cause)) {
127 double major_pause_in_seconds = _major_timer.seconds();
128 double major_pause_in_ms = major_pause_in_seconds * MILLIUNITS;
129
130 // Sample for performance counter
131 _avg_major_pause->sample(major_pause_in_seconds);
132
133 // Cost of collection (unit-less)
134 double collection_cost = 0.0;
135 if ((_latest_major_mutator_interval_seconds > 0.0) &&
136 (major_pause_in_seconds > 0.0)) {
137 double interval_in_seconds =
138 _latest_major_mutator_interval_seconds + major_pause_in_seconds;
139 collection_cost =
140 major_pause_in_seconds / interval_in_seconds;
141 avg_major_gc_cost()->sample(collection_cost);
142
143 // Sample for performance counter
144 _avg_major_interval->sample(interval_in_seconds);
145 }
146
147 // Calculate variables used to estimate pause time vs. gen sizes
148 double eden_size_in_mbytes = ((double)_eden_size)/((double)M);
149 double promo_size_in_mbytes = ((double)_promo_size)/((double)M);
150 _major_pause_old_estimator->update(promo_size_in_mbytes,
151 major_pause_in_ms);
152 _major_pause_young_estimator->update(eden_size_in_mbytes,
153 major_pause_in_ms);
154
155 log_trace(gc, ergo)("psAdaptiveSizePolicy::major_collection_end: major gc cost: %f average: %f",
156 collection_cost,avg_major_gc_cost()->average());
157 log_trace(gc, ergo)(" major pause: %f major period %f",
158 major_pause_in_ms, _latest_major_mutator_interval_seconds * MILLIUNITS);
159
160 // Calculate variable used to estimate collection cost vs. gen sizes
161 assert(collection_cost >= 0.0, "Expected to be non-negative");
162 _major_collection_estimator->update(promo_size_in_mbytes,
163 collection_cost);
164 }
165
166 // Update the amount live at the end of a full GC
167 _live_at_last_full_gc = amount_live;
168
169 // The policy does not have enough data until at least some major collections
170 // have been done.
171 if (_avg_major_pause->count() >= AdaptiveSizePolicyReadyThreshold) {
172 _old_gen_policy_is_ready = true;
173 }
174
175 // Interval times use this timer to measure the interval that
176 // the mutator runs. Reset after the GC pause has been measured.
177 _major_timer.reset();
178 _major_timer.start();
179 }
180
181 // If the remaining free space in the old generation is less that
182 // that expected to be needed by the next collection, do a full
183 // collection now.
184 bool PSAdaptiveSizePolicy::should_full_GC(size_t old_free_in_bytes) {
185
186 // A similar test is done in the scavenge's should_attempt_scavenge(). If
187 // this is changed, decide if that test should also be changed.
188 bool result = padded_average_promoted_in_bytes() > (float) old_free_in_bytes;
189 log_trace(gc, ergo)("%s after scavenge average_promoted " SIZE_FORMAT " padded_average_promoted " SIZE_FORMAT " free in old gen " SIZE_FORMAT,
190 result ? "Full" : "No full",
191 (size_t) average_promoted_in_bytes(),
192 (size_t) padded_average_promoted_in_bytes(),
193 old_free_in_bytes);
194 return result;
195 }
196
197 void PSAdaptiveSizePolicy::clear_generation_free_space_flags() {
198
199 AdaptiveSizePolicy::clear_generation_free_space_flags();
200
201 set_change_old_gen_for_min_pauses(0);
202
203 set_change_young_gen_for_maj_pauses(0);
204 }
205
206 // If this is not a full GC, only test and modify the young generation.
207
208 void PSAdaptiveSizePolicy::compute_generations_free_space(
209 size_t young_live,
210 size_t eden_live,
211 size_t old_live,
212 size_t cur_eden,
213 size_t max_old_gen_size,
214 size_t max_eden_size,
215 bool is_full_gc) {
216 compute_eden_space_size(young_live,
217 eden_live,
218 cur_eden,
219 max_eden_size,
220 is_full_gc);
221
222 compute_old_gen_free_space(old_live,
223 cur_eden,
224 max_old_gen_size,
225 is_full_gc);
226 }
227
228 void PSAdaptiveSizePolicy::compute_eden_space_size(
229 size_t young_live,
230 size_t eden_live,
231 size_t cur_eden,
232 size_t max_eden_size,
233 bool is_full_gc) {
234
235 // Update statistics
236 // Time statistics are updated as we go, update footprint stats here
237 _avg_base_footprint->sample(BaseFootPrintEstimate);
238 avg_young_live()->sample(young_live);
239 avg_eden_live()->sample(eden_live);
240
241 // This code used to return if the policy was not ready , i.e.,
242 // policy_is_ready() returning false. The intent was that
243 // decisions below needed major collection times and so could
244 // not be made before two major collections. A consequence was
245 // adjustments to the young generation were not done until after
246 // two major collections even if the minor collections times
247 // exceeded the requested goals. Now let the young generation
248 // adjust for the minor collection times. Major collection times
249 // will be zero for the first collection and will naturally be
250 // ignored. Tenured generation adjustments are only made at the
251 // full collections so until the second major collection has
252 // been reached, no tenured generation adjustments will be made.
253
254 // Until we know better, desired promotion size uses the last calculation
255 size_t desired_promo_size = _promo_size;
256
257 // Start eden at the current value. The desired value that is stored
258 // in _eden_size is not bounded by constraints of the heap and can
259 // run away.
260 //
261 // As expected setting desired_eden_size to the current
262 // value of desired_eden_size as a starting point
263 // caused desired_eden_size to grow way too large and caused
264 // an overflow down stream. It may have improved performance in
265 // some case but is dangerous.
266 size_t desired_eden_size = cur_eden;
267
268 // Cache some values. There's a bit of work getting these, so
269 // we might save a little time.
270 const double major_cost = major_gc_cost();
271 const double minor_cost = minor_gc_cost();
272
273 // This method sets the desired eden size. That plus the
274 // desired survivor space sizes sets the desired young generation
275 // size. This methods does not know what the desired survivor
276 // size is but expects that other policy will attempt to make
277 // the survivor sizes compatible with the live data in the
278 // young generation. This limit is an estimate of the space left
279 // in the young generation after the survivor spaces have been
280 // subtracted out.
281 size_t eden_limit = max_eden_size;
282
283 const double gc_cost_limit = GCTimeLimit / 100.0;
284
285 // Which way should we go?
286 // if pause requirement is not met
287 // adjust size of any generation with average paus exceeding
288 // the pause limit. Adjust one pause at a time (the larger)
289 // and only make adjustments for the major pause at full collections.
290 // else if throughput requirement not met
291 // adjust the size of the generation with larger gc time. Only
292 // adjust one generation at a time.
293 // else
294 // adjust down the total heap size. Adjust down the larger of the
295 // generations.
296
297 // Add some checks for a threshold for a change. For example,
298 // a change less than the necessary alignment is probably not worth
299 // attempting.
300
301
302 if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) ||
303 (_avg_major_pause->padded_average() > gc_pause_goal_sec())) {
304 //
305 // Check pauses
306 //
307 // Make changes only to affect one of the pauses (the larger)
308 // at a time.
309 adjust_eden_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size);
310
311 } else if (_avg_minor_pause->padded_average() > gc_minor_pause_goal_sec()) {
312 // Adjust only for the minor pause time goal
313 adjust_eden_for_minor_pause_time(is_full_gc, &desired_eden_size);
314
315 } else if(adjusted_mutator_cost() < _throughput_goal) {
316 // This branch used to require that (mutator_cost() > 0.0 in 1.4.2.
317 // This sometimes resulted in skipping to the minimize footprint
318 // code. Change this to try and reduce GC time if mutator time is
319 // negative for whatever reason. Or for future consideration,
320 // bail out of the code if mutator time is negative.
321 //
322 // Throughput
323 //
324 assert(major_cost >= 0.0, "major cost is < 0.0");
325 assert(minor_cost >= 0.0, "minor cost is < 0.0");
326 // Try to reduce the GC times.
327 adjust_eden_for_throughput(is_full_gc, &desired_eden_size);
328
329 } else {
330
331 // Be conservative about reducing the footprint.
332 // Do a minimum number of major collections first.
333 // Have reasonable averages for major and minor collections costs.
334 if (UseAdaptiveSizePolicyFootprintGoal &&
335 young_gen_policy_is_ready() &&
336 avg_major_gc_cost()->average() >= 0.0 &&
337 avg_minor_gc_cost()->average() >= 0.0) {
338 size_t desired_sum = desired_eden_size + desired_promo_size;
339 desired_eden_size = adjust_eden_for_footprint(desired_eden_size, desired_sum);
340 }
341 }
342
343 // Note we make the same tests as in the code block below; the code
344 // seems a little easier to read with the printing in another block.
345 if (desired_eden_size > eden_limit) {
346 log_debug(gc, ergo)(
347 "PSAdaptiveSizePolicy::compute_eden_space_size limits:"
348 " desired_eden_size: " SIZE_FORMAT
349 " old_eden_size: " SIZE_FORMAT
350 " eden_limit: " SIZE_FORMAT
351 " cur_eden: " SIZE_FORMAT
352 " max_eden_size: " SIZE_FORMAT
353 " avg_young_live: " SIZE_FORMAT,
354 desired_eden_size, _eden_size, eden_limit, cur_eden,
355 max_eden_size, (size_t)avg_young_live()->average());
356 }
357 if (gc_cost() > gc_cost_limit) {
358 log_debug(gc, ergo)(
359 "PSAdaptiveSizePolicy::compute_eden_space_size: gc time limit"
360 " gc_cost: %f "
361 " GCTimeLimit: " UINTX_FORMAT,
362 gc_cost(), GCTimeLimit);
363 }
364
365 // Align everything and make a final limit check
366 desired_eden_size = align_up(desired_eden_size, _space_alignment);
367 desired_eden_size = MAX2(desired_eden_size, _space_alignment);
368
369 eden_limit = align_down(eden_limit, _space_alignment);
370
371 // And one last limit check, now that we've aligned things.
372 if (desired_eden_size > eden_limit) {
373 // If the policy says to get a larger eden but
374 // is hitting the limit, don't decrease eden.
375 // This can lead to a general drifting down of the
376 // eden size. Let the tenuring calculation push more
377 // into the old gen.
378 desired_eden_size = MAX2(eden_limit, cur_eden);
379 }
380
381 log_debug(gc, ergo)("PSAdaptiveSizePolicy::compute_eden_space_size: costs minor_time: %f major_cost: %f mutator_cost: %f throughput_goal: %f",
382 minor_gc_cost(), major_gc_cost(), mutator_cost(), _throughput_goal);
383
384 log_trace(gc, ergo)("Minor_pause: %f major_pause: %f minor_interval: %f major_interval: %fpause_goal: %f",
385 _avg_minor_pause->padded_average(),
386 _avg_major_pause->padded_average(),
387 _avg_minor_interval->average(),
388 _avg_major_interval->average(),
389 gc_pause_goal_sec());
390
391 log_debug(gc, ergo)("Live_space: " SIZE_FORMAT " free_space: " SIZE_FORMAT,
392 live_space(), free_space());
393
394 log_trace(gc, ergo)("Base_footprint: " SIZE_FORMAT " avg_young_live: " SIZE_FORMAT " avg_old_live: " SIZE_FORMAT,
395 (size_t)_avg_base_footprint->average(),
396 (size_t)avg_young_live()->average(),
397 (size_t)avg_old_live()->average());
398
399 log_debug(gc, ergo)("Old eden_size: " SIZE_FORMAT " desired_eden_size: " SIZE_FORMAT,
400 _eden_size, desired_eden_size);
401
402 set_eden_size(desired_eden_size);
403 }
404
405 void PSAdaptiveSizePolicy::compute_old_gen_free_space(
406 size_t old_live,
407 size_t cur_eden,
408 size_t max_old_gen_size,
409 bool is_full_gc) {
410
411 // Update statistics
412 // Time statistics are updated as we go, update footprint stats here
413 if (is_full_gc) {
414 // old_live is only accurate after a full gc
415 avg_old_live()->sample(old_live);
416 }
417
418 // This code used to return if the policy was not ready , i.e.,
419 // policy_is_ready() returning false. The intent was that
420 // decisions below needed major collection times and so could
421 // not be made before two major collections. A consequence was
422 // adjustments to the young generation were not done until after
423 // two major collections even if the minor collections times
424 // exceeded the requested goals. Now let the young generation
425 // adjust for the minor collection times. Major collection times
426 // will be zero for the first collection and will naturally be
427 // ignored. Tenured generation adjustments are only made at the
428 // full collections so until the second major collection has
429 // been reached, no tenured generation adjustments will be made.
430
431 // Until we know better, desired promotion size uses the last calculation
432 size_t desired_promo_size = _promo_size;
433
434 // Start eden at the current value. The desired value that is stored
435 // in _eden_size is not bounded by constraints of the heap and can
436 // run away.
437 //
438 // As expected setting desired_eden_size to the current
439 // value of desired_eden_size as a starting point
440 // caused desired_eden_size to grow way too large and caused
441 // an overflow down stream. It may have improved performance in
442 // some case but is dangerous.
443 size_t desired_eden_size = cur_eden;
444
445 // Cache some values. There's a bit of work getting these, so
446 // we might save a little time.
447 const double major_cost = major_gc_cost();
448 const double minor_cost = minor_gc_cost();
449
450 // Limits on our growth
451 size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average());
452
453 // But don't force a promo size below the current promo size. Otherwise,
454 // the promo size will shrink for no good reason.
455 promo_limit = MAX2(promo_limit, _promo_size);
456
457 const double gc_cost_limit = GCTimeLimit/100.0;
458
459 // Which way should we go?
460 // if pause requirement is not met
461 // adjust size of any generation with average paus exceeding
462 // the pause limit. Adjust one pause at a time (the larger)
463 // and only make adjustments for the major pause at full collections.
464 // else if throughput requirement not met
465 // adjust the size of the generation with larger gc time. Only
466 // adjust one generation at a time.
467 // else
468 // adjust down the total heap size. Adjust down the larger of the
469 // generations.
470
471 // Add some checks for a threshold for a change. For example,
472 // a change less than the necessary alignment is probably not worth
473 // attempting.
474
475 if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) ||
476 (_avg_major_pause->padded_average() > gc_pause_goal_sec())) {
477 //
478 // Check pauses
479 //
480 // Make changes only to affect one of the pauses (the larger)
481 // at a time.
482 if (is_full_gc) {
483 set_decide_at_full_gc(decide_at_full_gc_true);
484 adjust_promo_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size);
485 }
486 } else if (adjusted_mutator_cost() < _throughput_goal) {
487 // This branch used to require that (mutator_cost() > 0.0 in 1.4.2.
488 // This sometimes resulted in skipping to the minimize footprint
489 // code. Change this to try and reduce GC time if mutator time is
490 // negative for whatever reason. Or for future consideration,
491 // bail out of the code if mutator time is negative.
492 //
493 // Throughput
494 //
495 assert(major_cost >= 0.0, "major cost is < 0.0");
496 assert(minor_cost >= 0.0, "minor cost is < 0.0");
497 // Try to reduce the GC times.
498 if (is_full_gc) {
499 set_decide_at_full_gc(decide_at_full_gc_true);
500 adjust_promo_for_throughput(is_full_gc, &desired_promo_size);
501 }
502 } else {
503
504 // Be conservative about reducing the footprint.
505 // Do a minimum number of major collections first.
506 // Have reasonable averages for major and minor collections costs.
507 if (UseAdaptiveSizePolicyFootprintGoal &&
508 young_gen_policy_is_ready() &&
509 avg_major_gc_cost()->average() >= 0.0 &&
510 avg_minor_gc_cost()->average() >= 0.0) {
511 if (is_full_gc) {
512 set_decide_at_full_gc(decide_at_full_gc_true);
513 size_t desired_sum = desired_eden_size + desired_promo_size;
514 desired_promo_size = adjust_promo_for_footprint(desired_promo_size, desired_sum);
515 }
516 }
517 }
518
519 // Note we make the same tests as in the code block below; the code
520 // seems a little easier to read with the printing in another block.
521 if (desired_promo_size > promo_limit) {
522 // "free_in_old_gen" was the original value for used for promo_limit
523 size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
524 log_debug(gc, ergo)(
525 "PSAdaptiveSizePolicy::compute_old_gen_free_space limits:"
526 " desired_promo_size: " SIZE_FORMAT
527 " promo_limit: " SIZE_FORMAT
528 " free_in_old_gen: " SIZE_FORMAT
529 " max_old_gen_size: " SIZE_FORMAT
530 " avg_old_live: " SIZE_FORMAT,
531 desired_promo_size, promo_limit, free_in_old_gen,
532 max_old_gen_size, (size_t) avg_old_live()->average());
533 }
534 if (gc_cost() > gc_cost_limit) {
535 log_debug(gc, ergo)(
536 "PSAdaptiveSizePolicy::compute_old_gen_free_space: gc time limit"
537 " gc_cost: %f "
538 " GCTimeLimit: " UINTX_FORMAT,
539 gc_cost(), GCTimeLimit);
540 }
541
542 // Align everything and make a final limit check
543 desired_promo_size = align_up(desired_promo_size, _space_alignment);
544 desired_promo_size = MAX2(desired_promo_size, _space_alignment);
545
546 promo_limit = align_down(promo_limit, _space_alignment);
547
548 // And one last limit check, now that we've aligned things.
549 desired_promo_size = MIN2(desired_promo_size, promo_limit);
550
551 // Timing stats
552 log_debug(gc, ergo)("PSAdaptiveSizePolicy::compute_old_gen_free_space: costs minor_time: %f major_cost: %f mutator_cost: %f throughput_goal: %f",
553 minor_gc_cost(), major_gc_cost(), mutator_cost(), _throughput_goal);
554
555 log_trace(gc, ergo)("Minor_pause: %f major_pause: %f minor_interval: %f major_interval: %f pause_goal: %f",
556 _avg_minor_pause->padded_average(),
557 _avg_major_pause->padded_average(),
558 _avg_minor_interval->average(),
559 _avg_major_interval->average(),
560 gc_pause_goal_sec());
561
562 // Footprint stats
563 log_debug(gc, ergo)("Live_space: " SIZE_FORMAT " free_space: " SIZE_FORMAT,
564 live_space(), free_space());
565
566 log_trace(gc, ergo)("Base_footprint: " SIZE_FORMAT " avg_young_live: " SIZE_FORMAT " avg_old_live: " SIZE_FORMAT,
567 (size_t)_avg_base_footprint->average(),
568 (size_t)avg_young_live()->average(),
569 (size_t)avg_old_live()->average());
570
571 log_debug(gc, ergo)("Old promo_size: " SIZE_FORMAT " desired_promo_size: " SIZE_FORMAT,
572 _promo_size, desired_promo_size);
573
574 set_promo_size(desired_promo_size);
575 }
576
577 void PSAdaptiveSizePolicy::decay_supplemental_growth(bool is_full_gc) {
578 // Decay the supplemental increment? Decay the supplement growth
579 // factor even if it is not used. It is only meant to give a boost
580 // to the initial growth and if it is not used, then it was not
581 // needed.
582 if (is_full_gc) {
583 // Don't wait for the threshold value for the major collections. If
584 // here, the supplemental growth term was used and should decay.
585 if ((_avg_major_pause->count() % TenuredGenerationSizeSupplementDecay)
586 == 0) {
587 _old_gen_size_increment_supplement =
588 _old_gen_size_increment_supplement >> 1;
589 }
590 } else {
591 if ((_avg_minor_pause->count() >= AdaptiveSizePolicyReadyThreshold) &&
592 (_avg_minor_pause->count() % YoungGenerationSizeSupplementDecay) == 0) {
593 _young_gen_size_increment_supplement =
594 _young_gen_size_increment_supplement >> 1;
595 }
596 }
597 }
598
599 void PSAdaptiveSizePolicy::adjust_eden_for_minor_pause_time(bool is_full_gc,
600 size_t* desired_eden_size_ptr) {
601
602 // Adjust the young generation size to reduce pause time of
603 // of collections.
604 //
605 // The AdaptiveSizePolicyInitializingSteps test is not used
606 // here. It has not seemed to be needed but perhaps should
607 // be added for consistency.
608 if (minor_pause_young_estimator()->decrement_will_decrease()) {
609 // reduce eden size
610 set_change_young_gen_for_min_pauses(
611 decrease_young_gen_for_min_pauses_true);
612 *desired_eden_size_ptr = *desired_eden_size_ptr -
613 eden_decrement_aligned_down(*desired_eden_size_ptr);
614 } else {
615 // EXPERIMENTAL ADJUSTMENT
616 // Only record that the estimator indicated such an action.
617 // *desired_eden_size_ptr = *desired_eden_size_ptr + eden_heap_delta;
618 set_change_young_gen_for_min_pauses(
619 increase_young_gen_for_min_pauses_true);
620 }
621 }
622
623 void PSAdaptiveSizePolicy::adjust_promo_for_pause_time(bool is_full_gc,
624 size_t* desired_promo_size_ptr,
625 size_t* desired_eden_size_ptr) {
626
627 size_t promo_heap_delta = 0;
628 // Add some checks for a threshold for a change. For example,
629 // a change less than the required alignment is probably not worth
630 // attempting.
631
632 if (_avg_minor_pause->padded_average() <= _avg_major_pause->padded_average() && is_full_gc) {
633 // Adjust for the major pause time only at full gc's because the
634 // affects of a change can only be seen at full gc's.
635
636 // Reduce old generation size to reduce pause?
637 if (major_pause_old_estimator()->decrement_will_decrease()) {
638 // reduce old generation size
639 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true);
640 promo_heap_delta = promo_decrement_aligned_down(*desired_promo_size_ptr);
641 *desired_promo_size_ptr = _promo_size - promo_heap_delta;
642 } else {
643 // EXPERIMENTAL ADJUSTMENT
644 // Only record that the estimator indicated such an action.
645 // *desired_promo_size_ptr = _promo_size +
646 // promo_increment_aligned_up(*desired_promo_size_ptr);
647 set_change_old_gen_for_maj_pauses(increase_old_gen_for_maj_pauses_true);
648 }
649 }
650
651 log_trace(gc, ergo)(
652 "PSAdaptiveSizePolicy::adjust_promo_for_pause_time "
653 "adjusting gen sizes for major pause (avg %f goal %f). "
654 "desired_promo_size " SIZE_FORMAT " promo delta " SIZE_FORMAT,
655 _avg_major_pause->average(), gc_pause_goal_sec(),
656 *desired_promo_size_ptr, promo_heap_delta);
657 }
658
659 void PSAdaptiveSizePolicy::adjust_eden_for_pause_time(bool is_full_gc,
660 size_t* desired_promo_size_ptr,
661 size_t* desired_eden_size_ptr) {
662
663 size_t eden_heap_delta = 0;
664 // Add some checks for a threshold for a change. For example,
665 // a change less than the required alignment is probably not worth
666 // attempting.
667 if (_avg_minor_pause->padded_average() > _avg_major_pause->padded_average()) {
668 adjust_eden_for_minor_pause_time(is_full_gc, desired_eden_size_ptr);
669 }
670 log_trace(gc, ergo)(
671 "PSAdaptiveSizePolicy::adjust_eden_for_pause_time "
672 "adjusting gen sizes for major pause (avg %f goal %f). "
673 "desired_eden_size " SIZE_FORMAT " eden delta " SIZE_FORMAT,
674 _avg_major_pause->average(), gc_pause_goal_sec(),
675 *desired_eden_size_ptr, eden_heap_delta);
676 }
677
678 void PSAdaptiveSizePolicy::adjust_promo_for_throughput(bool is_full_gc,
679 size_t* desired_promo_size_ptr) {
680
681 // Add some checks for a threshold for a change. For example,
682 // a change less than the required alignment is probably not worth
683 // attempting.
684
685 if ((gc_cost() + mutator_cost()) == 0.0) {
686 return;
687 }
688
689 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",
690 is_full_gc, *desired_promo_size_ptr, mutator_cost(), major_gc_cost(), minor_gc_cost());
691
692 // Tenured generation
693 if (is_full_gc) {
694 // Calculate the change to use for the tenured gen.
695 size_t scaled_promo_heap_delta = 0;
696 // Can the increment to the generation be scaled?
697 if (gc_cost() >= 0.0 && major_gc_cost() >= 0.0) {
698 size_t promo_heap_delta =
699 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
700 double scale_by_ratio = major_gc_cost() / gc_cost();
701 scaled_promo_heap_delta =
702 (size_t) (scale_by_ratio * (double) promo_heap_delta);
703 log_trace(gc, ergo)("Scaled tenured increment: " SIZE_FORMAT " by %f down to " SIZE_FORMAT,
704 promo_heap_delta, scale_by_ratio, scaled_promo_heap_delta);
705 } else if (major_gc_cost() >= 0.0) {
706 // Scaling is not going to work. If the major gc time is the
707 // larger, give it a full increment.
708 if (major_gc_cost() >= minor_gc_cost()) {
709 scaled_promo_heap_delta =
710 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
711 }
712 } else {
713 // Don't expect to get here but it's ok if it does
714 // in the product build since the delta will be 0
715 // and nothing will change.
716 assert(false, "Unexpected value for gc costs");
717 }
718
719 switch (AdaptiveSizeThroughPutPolicy) {
720 case 1:
721 // Early in the run the statistics might not be good. Until
722 // a specific number of collections have been, use the heuristic
723 // that a larger generation size means lower collection costs.
724 if (major_collection_estimator()->increment_will_decrease() ||
725 (_old_gen_change_for_major_throughput
726 <= AdaptiveSizePolicyInitializingSteps)) {
727 // Increase tenured generation size to reduce major collection cost
728 if ((*desired_promo_size_ptr + scaled_promo_heap_delta) >
729 *desired_promo_size_ptr) {
730 *desired_promo_size_ptr = _promo_size + scaled_promo_heap_delta;
731 }
732 set_change_old_gen_for_throughput(
733 increase_old_gen_for_throughput_true);
734 _old_gen_change_for_major_throughput++;
735 } else {
736 // EXPERIMENTAL ADJUSTMENT
737 // Record that decreasing the old gen size would decrease
738 // the major collection cost but don't do it.
739 // *desired_promo_size_ptr = _promo_size -
740 // promo_decrement_aligned_down(*desired_promo_size_ptr);
741 set_change_old_gen_for_throughput(
742 decrease_old_gen_for_throughput_true);
743 }
744
745 break;
746 default:
747 // Simplest strategy
748 if ((*desired_promo_size_ptr + scaled_promo_heap_delta) >
749 *desired_promo_size_ptr) {
750 *desired_promo_size_ptr = *desired_promo_size_ptr +
751 scaled_promo_heap_delta;
752 }
753 set_change_old_gen_for_throughput(
754 increase_old_gen_for_throughput_true);
755 _old_gen_change_for_major_throughput++;
756 }
757
758 log_trace(gc, ergo)("Adjusting tenured gen for throughput (avg %f goal %f). desired_promo_size " SIZE_FORMAT " promo_delta " SIZE_FORMAT ,
759 mutator_cost(),
760 _throughput_goal,
761 *desired_promo_size_ptr, scaled_promo_heap_delta);
762 }
763 }
764
765 void PSAdaptiveSizePolicy::adjust_eden_for_throughput(bool is_full_gc,
766 size_t* desired_eden_size_ptr) {
767
768 // Add some checks for a threshold for a change. For example,
769 // a change less than the required alignment is probably not worth
770 // attempting.
771
772 if ((gc_cost() + mutator_cost()) == 0.0) {
773 return;
774 }
775
776 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",
777 is_full_gc, *desired_eden_size_ptr, mutator_cost(), major_gc_cost(), minor_gc_cost());
778
779 // Young generation
780 size_t scaled_eden_heap_delta = 0;
781 // Can the increment to the generation be scaled?
782 if (gc_cost() >= 0.0 && minor_gc_cost() >= 0.0) {
783 size_t eden_heap_delta =
784 eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr);
785 double scale_by_ratio = minor_gc_cost() / gc_cost();
786 assert(scale_by_ratio <= 1.0 && scale_by_ratio >= 0.0, "Scaling is wrong");
787 scaled_eden_heap_delta =
788 (size_t) (scale_by_ratio * (double) eden_heap_delta);
789 log_trace(gc, ergo)("Scaled eden increment: " SIZE_FORMAT " by %f down to " SIZE_FORMAT,
790 eden_heap_delta, scale_by_ratio, scaled_eden_heap_delta);
791 } else if (minor_gc_cost() >= 0.0) {
792 // Scaling is not going to work. If the minor gc time is the
793 // larger, give it a full increment.
794 if (minor_gc_cost() > major_gc_cost()) {
795 scaled_eden_heap_delta =
796 eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr);
797 }
798 } else {
799 // Don't expect to get here but it's ok if it does
800 // in the product build since the delta will be 0
801 // and nothing will change.
802 assert(false, "Unexpected value for gc costs");
803 }
804
805 // Use a heuristic for some number of collections to give
806 // the averages time to settle down.
807 switch (AdaptiveSizeThroughPutPolicy) {
808 case 1:
809 if (minor_collection_estimator()->increment_will_decrease() ||
810 (_young_gen_change_for_minor_throughput
811 <= AdaptiveSizePolicyInitializingSteps)) {
812 // Expand young generation size to reduce frequency of
813 // of collections.
814 if ((*desired_eden_size_ptr + scaled_eden_heap_delta) >
815 *desired_eden_size_ptr) {
816 *desired_eden_size_ptr =
817 *desired_eden_size_ptr + scaled_eden_heap_delta;
818 }
819 set_change_young_gen_for_throughput(
820 increase_young_gen_for_througput_true);
821 _young_gen_change_for_minor_throughput++;
822 } else {
823 // EXPERIMENTAL ADJUSTMENT
824 // Record that decreasing the young gen size would decrease
825 // the minor collection cost but don't do it.
826 // *desired_eden_size_ptr = _eden_size -
827 // eden_decrement_aligned_down(*desired_eden_size_ptr);
828 set_change_young_gen_for_throughput(
829 decrease_young_gen_for_througput_true);
830 }
831 break;
832 default:
833 if ((*desired_eden_size_ptr + scaled_eden_heap_delta) >
834 *desired_eden_size_ptr) {
835 *desired_eden_size_ptr =
836 *desired_eden_size_ptr + scaled_eden_heap_delta;
837 }
838 set_change_young_gen_for_throughput(
839 increase_young_gen_for_througput_true);
840 _young_gen_change_for_minor_throughput++;
841 }
842
843 log_trace(gc, ergo)("Adjusting eden for throughput (avg %f goal %f). desired_eden_size " SIZE_FORMAT " eden delta " SIZE_FORMAT,
844 mutator_cost(), _throughput_goal, *desired_eden_size_ptr, scaled_eden_heap_delta);
845 }
846
847 size_t PSAdaptiveSizePolicy::adjust_promo_for_footprint(
848 size_t desired_promo_size, size_t desired_sum) {
849 assert(desired_promo_size <= desired_sum, "Inconsistent parameters");
850 set_decrease_for_footprint(decrease_old_gen_for_footprint_true);
851
852 size_t change = promo_decrement(desired_promo_size);
853 change = scale_down(change, desired_promo_size, desired_sum);
854
855 size_t reduced_size = desired_promo_size - change;
856
857 log_trace(gc, ergo)(
858 "AdaptiveSizePolicy::adjust_promo_for_footprint "
859 "adjusting tenured gen for footprint. "
860 "starting promo size " SIZE_FORMAT
861 " reduced promo size " SIZE_FORMAT
862 " promo delta " SIZE_FORMAT,
863 desired_promo_size, reduced_size, change );
864
865 assert(reduced_size <= desired_promo_size, "Inconsistent result");
866 return reduced_size;
867 }
868
869 size_t PSAdaptiveSizePolicy::adjust_eden_for_footprint(
870 size_t desired_eden_size, size_t desired_sum) {
871 assert(desired_eden_size <= desired_sum, "Inconsistent parameters");
872 set_decrease_for_footprint(decrease_young_gen_for_footprint_true);
873
874 size_t change = eden_decrement(desired_eden_size);
875 change = scale_down(change, desired_eden_size, desired_sum);
876
877 size_t reduced_size = desired_eden_size - change;
878
879 log_trace(gc, ergo)(
880 "AdaptiveSizePolicy::adjust_eden_for_footprint "
881 "adjusting eden for footprint. "
882 " starting eden size " SIZE_FORMAT
883 " reduced eden size " SIZE_FORMAT
884 " eden delta " SIZE_FORMAT,
885 desired_eden_size, reduced_size, change);
886
887 assert(reduced_size <= desired_eden_size, "Inconsistent result");
888 return reduced_size;
889 }
890
891 // Scale down "change" by the factor
892 // part / total
893 // Don't align the results.
894
895 size_t PSAdaptiveSizePolicy::scale_down(size_t change,
896 double part,
897 double total) {
898 assert(part <= total, "Inconsistent input");
899 size_t reduced_change = change;
900 if (total > 0) {
901 double fraction = part / total;
902 reduced_change = (size_t) (fraction * (double) change);
903 }
904 assert(reduced_change <= change, "Inconsistent result");
905 return reduced_change;
906 }
907
908 size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden,
909 uint percent_change) {
910 size_t eden_heap_delta;
911 eden_heap_delta = cur_eden / 100 * percent_change;
912 return eden_heap_delta;
913 }
914
915 size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden) {
916 return eden_increment(cur_eden, YoungGenerationSizeIncrement);
917 }
918
919 size_t PSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) {
920 size_t result = eden_increment(cur_eden, YoungGenerationSizeIncrement);
921 return align_up(result, _space_alignment);
922 }
923
924 size_t PSAdaptiveSizePolicy::eden_increment_aligned_down(size_t cur_eden) {
925 size_t result = eden_increment(cur_eden);
926 return align_down(result, _space_alignment);
927 }
928
929 size_t PSAdaptiveSizePolicy::eden_increment_with_supplement_aligned_up(
930 size_t cur_eden) {
931 size_t result = eden_increment(cur_eden,
932 YoungGenerationSizeIncrement + _young_gen_size_increment_supplement);
933 return align_up(result, _space_alignment);
934 }
935
936 size_t PSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) {
937 size_t eden_heap_delta = eden_decrement(cur_eden);
938 return align_down(eden_heap_delta, _space_alignment);
939 }
940
941 size_t PSAdaptiveSizePolicy::eden_decrement(size_t cur_eden) {
942 size_t eden_heap_delta = eden_increment(cur_eden) /
943 AdaptiveSizeDecrementScaleFactor;
944 return eden_heap_delta;
945 }
946
947 size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo,
948 uint percent_change) {
949 size_t promo_heap_delta;
950 promo_heap_delta = cur_promo / 100 * percent_change;
951 return promo_heap_delta;
952 }
953
954 size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo) {
955 return promo_increment(cur_promo, TenuredGenerationSizeIncrement);
956 }
957
958 size_t PSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) {
959 size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement);
960 return align_up(result, _space_alignment);
961 }
962
963 size_t PSAdaptiveSizePolicy::promo_increment_aligned_down(size_t cur_promo) {
964 size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement);
965 return align_down(result, _space_alignment);
966 }
967
968 size_t PSAdaptiveSizePolicy::promo_increment_with_supplement_aligned_up(
969 size_t cur_promo) {
970 size_t result = promo_increment(cur_promo,
971 TenuredGenerationSizeIncrement + _old_gen_size_increment_supplement);
972 return align_up(result, _space_alignment);
973 }
974
975 size_t PSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) {
976 size_t promo_heap_delta = promo_decrement(cur_promo);
977 return align_down(promo_heap_delta, _space_alignment);
978 }
979
980 size_t PSAdaptiveSizePolicy::promo_decrement(size_t cur_promo) {
981 size_t promo_heap_delta = promo_increment(cur_promo);
982 promo_heap_delta = promo_heap_delta / AdaptiveSizeDecrementScaleFactor;
983 return promo_heap_delta;
984 }
985
986 uint PSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold(
987 bool is_survivor_overflow,
988 uint tenuring_threshold,
989 size_t survivor_limit) {
990 assert(survivor_limit >= _space_alignment,
991 "survivor_limit too small");
992 assert(is_aligned(survivor_limit, _space_alignment),
993 "survivor_limit not aligned");
994
995 // This method is called even if the tenuring threshold and survivor
996 // spaces are not adjusted so that the averages are sampled above.
997 if (!UsePSAdaptiveSurvivorSizePolicy ||
998 !young_gen_policy_is_ready()) {
999 return tenuring_threshold;
1000 }
1001
1002 // We'll decide whether to increase or decrease the tenuring
1003 // threshold based partly on the newly computed survivor size
1004 // (if we hit the maximum limit allowed, we'll always choose to
1005 // decrement the threshold).
1006 bool incr_tenuring_threshold = false;
1007 bool decr_tenuring_threshold = false;
1008
1009 set_decrement_tenuring_threshold_for_gc_cost(false);
1010 set_increment_tenuring_threshold_for_gc_cost(false);
1011 set_decrement_tenuring_threshold_for_survivor_limit(false);
1012
1013 if (!is_survivor_overflow) {
1014 // Keep running averages on how much survived
1015
1016 // We use the tenuring threshold to equalize the cost of major
1017 // and minor collections.
1018 // ThresholdTolerance is used to indicate how sensitive the
1019 // tenuring threshold is to differences in cost between the
1020 // collection types.
1021
1022 // Get the times of interest. This involves a little work, so
1023 // we cache the values here.
1024 const double major_cost = major_gc_cost();
1025 const double minor_cost = minor_gc_cost();
1026
1027 if (minor_cost > major_cost * _threshold_tolerance_percent) {
1028 // Minor times are getting too long; lower the threshold so
1029 // less survives and more is promoted.
1030 decr_tenuring_threshold = true;
1031 set_decrement_tenuring_threshold_for_gc_cost(true);
1032 } else if (major_cost > minor_cost * _threshold_tolerance_percent) {
1033 // Major times are too long, so we want less promotion.
1034 incr_tenuring_threshold = true;
1035 set_increment_tenuring_threshold_for_gc_cost(true);
1036 }
1037
1038 } else {
1039 // Survivor space overflow occurred, so promoted and survived are
1040 // not accurate. We'll make our best guess by combining survived
1041 // and promoted and count them as survivors.
1042 //
1043 // We'll lower the tenuring threshold to see if we can correct
1044 // things. Also, set the survivor size conservatively. We're
1045 // trying to avoid many overflows from occurring if defnew size
1046 // is just too small.
1047
1048 decr_tenuring_threshold = true;
1049 }
1050
1051 // The padded average also maintains a deviation from the average;
1052 // we use this to see how good of an estimate we have of what survived.
1053 // We're trying to pad the survivor size as little as possible without
1054 // overflowing the survivor spaces.
1055 size_t target_size = align_up((size_t)_avg_survived->padded_average(),
1056 _space_alignment);
1057 target_size = MAX2(target_size, _space_alignment);
1058
1059 if (target_size > survivor_limit) {
1060 // Target size is bigger than we can handle. Let's also reduce
1061 // the tenuring threshold.
1062 target_size = survivor_limit;
1063 decr_tenuring_threshold = true;
1064 set_decrement_tenuring_threshold_for_survivor_limit(true);
1065 }
1066
1067 // Finally, increment or decrement the tenuring threshold, as decided above.
1068 // We test for decrementing first, as we might have hit the target size
1069 // limit.
1070 if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1071 if (tenuring_threshold > 1) {
1072 tenuring_threshold--;
1073 }
1074 } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1075 if (tenuring_threshold < MaxTenuringThreshold) {
1076 tenuring_threshold++;
1077 }
1078 }
1079
1080 // We keep a running average of the amount promoted which is used
1081 // to decide when we should collect the old generation (when
1082 // the amount of old gen free space is less than what we expect to
1083 // promote).
1084
1085 log_trace(gc, ergo)("avg_survived: %f avg_deviation: %f", _avg_survived->average(), _avg_survived->deviation());
1086 log_debug(gc, ergo)("avg_survived_padded_avg: %f", _avg_survived->padded_average());
1087
1088 log_trace(gc, ergo)("avg_promoted_avg: %f avg_promoted_dev: %f", avg_promoted()->average(), avg_promoted()->deviation());
1089 log_debug(gc, ergo)("avg_promoted_padded_avg: %f avg_pretenured_padded_avg: %f tenuring_thresh: %d target_size: " SIZE_FORMAT,
1090 avg_promoted()->padded_average(),
1091 _avg_pretenured->padded_average(),
1092 tenuring_threshold, target_size);
1093
1094 set_survivor_size(target_size);
1095
1096 return tenuring_threshold;
1097 }
1098
1099 void PSAdaptiveSizePolicy::update_averages(bool is_survivor_overflow,
1100 size_t survived,
1101 size_t promoted) {
1102 // Update averages
1103 if (!is_survivor_overflow) {
1104 // Keep running averages on how much survived
1105 _avg_survived->sample(survived);
1106 } else {
1107 size_t survived_guess = survived + promoted;
1108 _avg_survived->sample(survived_guess);
1109 }
1110 avg_promoted()->sample(promoted);
1111
1112 log_trace(gc, ergo)("AdaptiveSizePolicy::update_averages: survived: " SIZE_FORMAT " promoted: " SIZE_FORMAT " overflow: %s",
1113 survived, promoted, is_survivor_overflow ? "true" : "false");
1114 }
1115
1116 bool PSAdaptiveSizePolicy::print() const {
1117
1118 if (!UseAdaptiveSizePolicy) {
1119 return false;
1120 }
1121
1122 if (AdaptiveSizePolicy::print()) {
1123 AdaptiveSizePolicy::print_tenuring_threshold(PSScavenge::tenuring_threshold());
1124 return true;
1125 }
1126
1127 return false;
1128 }