1 /*
2 * Copyright (c) 2002, 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.
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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 #include "utilities/top.hpp"
36
37 #include <math.h>
38
39 PSAdaptiveSizePolicy::PSAdaptiveSizePolicy(size_t init_eden_size,
40 size_t init_promo_size,
41 size_t init_survivor_size,
42 size_t space_alignment,
43 double gc_pause_goal_sec,
44 double gc_minor_pause_goal_sec,
45 uint gc_cost_ratio) :
46 AdaptiveSizePolicy(init_eden_size,
47 init_promo_size,
48 init_survivor_size,
49 gc_pause_goal_sec,
50 gc_cost_ratio),
51 _collection_cost_margin_fraction(AdaptiveSizePolicyCollectionCostMargin / 100.0),
52 _space_alignment(space_alignment),
53 _live_at_last_full_gc(init_promo_size),
54 _gc_minor_pause_goal_sec(gc_minor_pause_goal_sec),
55 _latest_major_mutator_interval_seconds(0),
56 _young_gen_change_for_major_pause_count(0)
57 {
58 // Sizing policy statistics
59 _avg_major_pause =
60 new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding);
61 _avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
62 _avg_major_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
63
64 _avg_base_footprint = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight);
65 _major_pause_old_estimator =
66 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
67 _major_pause_young_estimator =
68 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
69 _major_collection_estimator =
70 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
71
72 _young_gen_size_increment_supplement = YoungGenerationSizeSupplement;
73 _old_gen_size_increment_supplement = TenuredGenerationSizeSupplement;
74
75 // Start the timers
76 _major_timer.start();
77
78 _old_gen_policy_is_ready = false;
79 }
80
81 size_t PSAdaptiveSizePolicy::calculate_free_based_on_live(size_t live, uintx ratio_as_percentage) {
82 // We want to calculate how much free memory there can be based on the
83 // amount of live data currently in the old gen. Using the formula:
84 // ratio * (free + live) = free
85 // Some equation solving later we get:
86 // free = (live * ratio) / (1 - ratio)
87
88 const double ratio = ratio_as_percentage / 100.0;
89 const double ratio_inverse = 1.0 - ratio;
90 const double tmp = live * ratio;
91 size_t free = (size_t)(tmp / ratio_inverse);
92
93 return free;
94 }
95
96 size_t PSAdaptiveSizePolicy::calculated_old_free_size_in_bytes() const {
97 size_t free_size = (size_t)(_promo_size + avg_promoted()->padded_average());
98 size_t live = ParallelScavengeHeap::heap()->old_gen()->used_in_bytes();
99
100 if (MinHeapFreeRatio != 0) {
101 size_t min_free = calculate_free_based_on_live(live, MinHeapFreeRatio);
102 free_size = MAX2(free_size, min_free);
103 }
104
105 if (MaxHeapFreeRatio != 100) {
106 size_t max_free = calculate_free_based_on_live(live, MaxHeapFreeRatio);
107 free_size = MIN2(max_free, free_size);
108 }
109
110 return free_size;
111 }
112
113 void PSAdaptiveSizePolicy::major_collection_begin() {
114 // Update the interval time
115 _major_timer.stop();
116 // Save most recent collection time
117 _latest_major_mutator_interval_seconds = _major_timer.seconds();
118 _major_timer.reset();
119 _major_timer.start();
120 }
121
122 void PSAdaptiveSizePolicy::update_minor_pause_old_estimator(
123 double minor_pause_in_ms) {
124 double promo_size_in_mbytes = ((double)_promo_size)/((double)M);
125 _minor_pause_old_estimator->update(promo_size_in_mbytes,
126 minor_pause_in_ms);
127 }
128
129 void PSAdaptiveSizePolicy::major_collection_end(size_t amount_live,
130 GCCause::Cause gc_cause) {
131 // Update the pause time.
132 _major_timer.stop();
133
134 if (should_update_promo_stats(gc_cause)) {
135 double major_pause_in_seconds = _major_timer.seconds();
136 double major_pause_in_ms = major_pause_in_seconds * MILLIUNITS;
137
138 // Sample for performance counter
139 _avg_major_pause->sample(major_pause_in_seconds);
140
141 // Cost of collection (unit-less)
142 double collection_cost = 0.0;
143 if ((_latest_major_mutator_interval_seconds > 0.0) &&
144 (major_pause_in_seconds > 0.0)) {
145 double interval_in_seconds =
146 _latest_major_mutator_interval_seconds + major_pause_in_seconds;
147 collection_cost =
148 major_pause_in_seconds / interval_in_seconds;
149 avg_major_gc_cost()->sample(collection_cost);
150
151 // Sample for performance counter
152 _avg_major_interval->sample(interval_in_seconds);
153 }
154
155 // Calculate variables used to estimate pause time vs. gen sizes
156 double eden_size_in_mbytes = ((double)_eden_size)/((double)M);
157 double promo_size_in_mbytes = ((double)_promo_size)/((double)M);
158 _major_pause_old_estimator->update(promo_size_in_mbytes,
159 major_pause_in_ms);
160 _major_pause_young_estimator->update(eden_size_in_mbytes,
161 major_pause_in_ms);
162
163 log_trace(gc, ergo)("psAdaptiveSizePolicy::major_collection_end: major gc cost: %f average: %f",
164 collection_cost,avg_major_gc_cost()->average());
165 log_trace(gc, ergo)(" major pause: %f major period %f",
166 major_pause_in_ms, _latest_major_mutator_interval_seconds * MILLIUNITS);
167
168 // Calculate variable used to estimate collection cost vs. gen sizes
169 assert(collection_cost >= 0.0, "Expected to be non-negative");
170 _major_collection_estimator->update(promo_size_in_mbytes,
171 collection_cost);
172 }
173
174 // Update the amount live at the end of a full GC
175 _live_at_last_full_gc = amount_live;
176
177 // The policy does not have enough data until at least some major collections
178 // have been done.
179 if (_avg_major_pause->count() >= AdaptiveSizePolicyReadyThreshold) {
180 _old_gen_policy_is_ready = true;
181 }
182
183 // Interval times use this timer to measure the interval that
184 // the mutator runs. Reset after the GC pause has been measured.
185 _major_timer.reset();
186 _major_timer.start();
187 }
188
189 // If the remaining free space in the old generation is less that
190 // that expected to be needed by the next collection, do a full
191 // collection now.
192 bool PSAdaptiveSizePolicy::should_full_GC(size_t old_free_in_bytes) {
193
194 // A similar test is done in the scavenge's should_attempt_scavenge(). If
195 // this is changed, decide if that test should also be changed.
196 bool result = padded_average_promoted_in_bytes() > (float) old_free_in_bytes;
197 log_trace(gc, ergo)("%s after scavenge average_promoted " SIZE_FORMAT " padded_average_promoted " SIZE_FORMAT " free in old gen " SIZE_FORMAT,
198 result ? "Full" : "No full",
199 (size_t) average_promoted_in_bytes(),
200 (size_t) padded_average_promoted_in_bytes(),
201 old_free_in_bytes);
202 return result;
203 }
204
205 void PSAdaptiveSizePolicy::clear_generation_free_space_flags() {
206
207 AdaptiveSizePolicy::clear_generation_free_space_flags();
208
209 set_change_old_gen_for_min_pauses(0);
210
211 set_change_young_gen_for_maj_pauses(0);
212 }
213
214 // If this is not a full GC, only test and modify the young generation.
215
216 void PSAdaptiveSizePolicy::compute_generations_free_space(
217 size_t young_live,
218 size_t eden_live,
219 size_t old_live,
220 size_t cur_eden,
221 size_t max_old_gen_size,
222 size_t max_eden_size,
223 bool is_full_gc) {
224 compute_eden_space_size(young_live,
225 eden_live,
226 cur_eden,
227 max_eden_size,
228 is_full_gc);
229
230 compute_old_gen_free_space(old_live,
231 cur_eden,
232 max_old_gen_size,
233 is_full_gc);
234 }
235
236 void PSAdaptiveSizePolicy::compute_eden_space_size(
237 size_t young_live,
238 size_t eden_live,
239 size_t cur_eden,
240 size_t max_eden_size,
241 bool is_full_gc) {
242
243 // Update statistics
244 // Time statistics are updated as we go, update footprint stats here
245 _avg_base_footprint->sample(BaseFootPrintEstimate);
246 avg_young_live()->sample(young_live);
247 avg_eden_live()->sample(eden_live);
248
249 // This code used to return if the policy was not ready , i.e.,
250 // policy_is_ready() returning false. The intent was that
251 // decisions below needed major collection times and so could
252 // not be made before two major collections. A consequence was
253 // adjustments to the young generation were not done until after
254 // two major collections even if the minor collections times
255 // exceeded the requested goals. Now let the young generation
256 // adjust for the minor collection times. Major collection times
257 // will be zero for the first collection and will naturally be
258 // ignored. Tenured generation adjustments are only made at the
259 // full collections so until the second major collection has
260 // been reached, no tenured generation adjustments will be made.
261
262 // Until we know better, desired promotion size uses the last calculation
263 size_t desired_promo_size = _promo_size;
264
265 // Start eden at the current value. The desired value that is stored
266 // in _eden_size is not bounded by constraints of the heap and can
267 // run away.
268 //
269 // As expected setting desired_eden_size to the current
270 // value of desired_eden_size as a starting point
271 // caused desired_eden_size to grow way too large and caused
272 // an overflow down stream. It may have improved performance in
273 // some case but is dangerous.
274 size_t desired_eden_size = cur_eden;
275
276 // Cache some values. There's a bit of work getting these, so
277 // we might save a little time.
278 const double major_cost = major_gc_cost();
279 const double minor_cost = minor_gc_cost();
280
281 // This method sets the desired eden size. That plus the
282 // desired survivor space sizes sets the desired young generation
283 // size. This methods does not know what the desired survivor
284 // size is but expects that other policy will attempt to make
285 // the survivor sizes compatible with the live data in the
286 // young generation. This limit is an estimate of the space left
287 // in the young generation after the survivor spaces have been
288 // subtracted out.
289 size_t eden_limit = max_eden_size;
290
291 const double gc_cost_limit = GCTimeLimit / 100.0;
292
293 // Which way should we go?
294 // if pause requirement is not met
295 // adjust size of any generation with average paus exceeding
296 // the pause limit. Adjust one pause at a time (the larger)
297 // and only make adjustments for the major pause at full collections.
298 // else if throughput requirement not met
299 // adjust the size of the generation with larger gc time. Only
300 // adjust one generation at a time.
301 // else
302 // adjust down the total heap size. Adjust down the larger of the
303 // generations.
304
305 // Add some checks for a threshold for a change. For example,
306 // a change less than the necessary alignment is probably not worth
307 // attempting.
308
309
310 if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) ||
311 (_avg_major_pause->padded_average() > gc_pause_goal_sec())) {
312 //
313 // Check pauses
314 //
315 // Make changes only to affect one of the pauses (the larger)
316 // at a time.
317 adjust_eden_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size);
318
319 } else if (_avg_minor_pause->padded_average() > gc_minor_pause_goal_sec()) {
320 // Adjust only for the minor pause time goal
321 adjust_eden_for_minor_pause_time(is_full_gc, &desired_eden_size);
322
323 } else if(adjusted_mutator_cost() < _throughput_goal) {
324 // This branch used to require that (mutator_cost() > 0.0 in 1.4.2.
325 // This sometimes resulted in skipping to the minimize footprint
326 // code. Change this to try and reduce GC time if mutator time is
327 // negative for whatever reason. Or for future consideration,
328 // bail out of the code if mutator time is negative.
329 //
330 // Throughput
331 //
332 assert(major_cost >= 0.0, "major cost is < 0.0");
333 assert(minor_cost >= 0.0, "minor cost is < 0.0");
334 // Try to reduce the GC times.
335 adjust_eden_for_throughput(is_full_gc, &desired_eden_size);
336
337 } else {
338
339 // Be conservative about reducing the footprint.
340 // Do a minimum number of major collections first.
341 // Have reasonable averages for major and minor collections costs.
342 if (UseAdaptiveSizePolicyFootprintGoal &&
343 young_gen_policy_is_ready() &&
344 avg_major_gc_cost()->average() >= 0.0 &&
345 avg_minor_gc_cost()->average() >= 0.0) {
346 size_t desired_sum = desired_eden_size + desired_promo_size;
347 desired_eden_size = adjust_eden_for_footprint(desired_eden_size, desired_sum);
348 }
349 }
350
351 // Note we make the same tests as in the code block below; the code
352 // seems a little easier to read with the printing in another block.
353 if (desired_eden_size > eden_limit) {
354 log_debug(gc, ergo)(
355 "PSAdaptiveSizePolicy::compute_eden_space_size limits:"
356 " desired_eden_size: " SIZE_FORMAT
357 " old_eden_size: " SIZE_FORMAT
358 " eden_limit: " SIZE_FORMAT
359 " cur_eden: " SIZE_FORMAT
360 " max_eden_size: " SIZE_FORMAT
361 " avg_young_live: " SIZE_FORMAT,
362 desired_eden_size, _eden_size, eden_limit, cur_eden,
363 max_eden_size, (size_t)avg_young_live()->average());
364 }
365 if (gc_cost() > gc_cost_limit) {
366 log_debug(gc, ergo)(
367 "PSAdaptiveSizePolicy::compute_eden_space_size: gc time limit"
368 " gc_cost: %f "
369 " GCTimeLimit: " UINTX_FORMAT,
370 gc_cost(), GCTimeLimit);
371 }
372
373 // Align everything and make a final limit check
374 desired_eden_size = align_size_up(desired_eden_size, _space_alignment);
375 desired_eden_size = MAX2(desired_eden_size, _space_alignment);
376
377 eden_limit = align_size_down(eden_limit, _space_alignment);
378
379 // And one last limit check, now that we've aligned things.
380 if (desired_eden_size > eden_limit) {
381 // If the policy says to get a larger eden but
382 // is hitting the limit, don't decrease eden.
383 // This can lead to a general drifting down of the
384 // eden size. Let the tenuring calculation push more
385 // into the old gen.
386 desired_eden_size = MAX2(eden_limit, cur_eden);
387 }
388
389 log_debug(gc, ergo)("PSAdaptiveSizePolicy::compute_eden_space_size: costs minor_time: %f major_cost: %f mutator_cost: %f throughput_goal: %f",
390 minor_gc_cost(), major_gc_cost(), mutator_cost(), _throughput_goal);
391
392 log_trace(gc, ergo)("Minor_pause: %f major_pause: %f minor_interval: %f major_interval: %fpause_goal: %f",
393 _avg_minor_pause->padded_average(),
394 _avg_major_pause->padded_average(),
395 _avg_minor_interval->average(),
396 _avg_major_interval->average(),
397 gc_pause_goal_sec());
398
399 log_debug(gc, ergo)("Live_space: " SIZE_FORMAT " free_space: " SIZE_FORMAT,
400 live_space(), free_space());
401
402 log_trace(gc, ergo)("Base_footprint: " SIZE_FORMAT " avg_young_live: " SIZE_FORMAT " avg_old_live: " SIZE_FORMAT,
403 (size_t)_avg_base_footprint->average(),
404 (size_t)avg_young_live()->average(),
405 (size_t)avg_old_live()->average());
406
407 log_debug(gc, ergo)("Old eden_size: " SIZE_FORMAT " desired_eden_size: " SIZE_FORMAT,
408 _eden_size, desired_eden_size);
409
410 set_eden_size(desired_eden_size);
411 }
412
413 void PSAdaptiveSizePolicy::compute_old_gen_free_space(
414 size_t old_live,
415 size_t cur_eden,
416 size_t max_old_gen_size,
417 bool is_full_gc) {
418
419 // Update statistics
420 // Time statistics are updated as we go, update footprint stats here
421 if (is_full_gc) {
422 // old_live is only accurate after a full gc
423 avg_old_live()->sample(old_live);
424 }
425
426 // This code used to return if the policy was not ready , i.e.,
427 // policy_is_ready() returning false. The intent was that
428 // decisions below needed major collection times and so could
429 // not be made before two major collections. A consequence was
430 // adjustments to the young generation were not done until after
431 // two major collections even if the minor collections times
432 // exceeded the requested goals. Now let the young generation
433 // adjust for the minor collection times. Major collection times
434 // will be zero for the first collection and will naturally be
435 // ignored. Tenured generation adjustments are only made at the
436 // full collections so until the second major collection has
437 // been reached, no tenured generation adjustments will be made.
438
439 // Until we know better, desired promotion size uses the last calculation
440 size_t desired_promo_size = _promo_size;
441
442 // Start eden at the current value. The desired value that is stored
443 // in _eden_size is not bounded by constraints of the heap and can
444 // run away.
445 //
446 // As expected setting desired_eden_size to the current
447 // value of desired_eden_size as a starting point
448 // caused desired_eden_size to grow way too large and caused
449 // an overflow down stream. It may have improved performance in
450 // some case but is dangerous.
451 size_t desired_eden_size = cur_eden;
452
453 // Cache some values. There's a bit of work getting these, so
454 // we might save a little time.
455 const double major_cost = major_gc_cost();
456 const double minor_cost = minor_gc_cost();
457
458 // Limits on our growth
459 size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average());
460
461 // But don't force a promo size below the current promo size. Otherwise,
462 // the promo size will shrink for no good reason.
463 promo_limit = MAX2(promo_limit, _promo_size);
464
465 const double gc_cost_limit = GCTimeLimit/100.0;
466
467 // Which way should we go?
468 // if pause requirement is not met
469 // adjust size of any generation with average paus exceeding
470 // the pause limit. Adjust one pause at a time (the larger)
471 // and only make adjustments for the major pause at full collections.
472 // else if throughput requirement not met
473 // adjust the size of the generation with larger gc time. Only
474 // adjust one generation at a time.
475 // else
476 // adjust down the total heap size. Adjust down the larger of the
477 // generations.
478
479 // Add some checks for a threshold for a change. For example,
480 // a change less than the necessary alignment is probably not worth
481 // attempting.
482
483 if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) ||
484 (_avg_major_pause->padded_average() > gc_pause_goal_sec())) {
485 //
486 // Check pauses
487 //
488 // Make changes only to affect one of the pauses (the larger)
489 // at a time.
490 if (is_full_gc) {
491 set_decide_at_full_gc(decide_at_full_gc_true);
492 adjust_promo_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size);
493 }
494 } else if (adjusted_mutator_cost() < _throughput_goal) {
495 // This branch used to require that (mutator_cost() > 0.0 in 1.4.2.
496 // This sometimes resulted in skipping to the minimize footprint
497 // code. Change this to try and reduce GC time if mutator time is
498 // negative for whatever reason. Or for future consideration,
499 // bail out of the code if mutator time is negative.
500 //
501 // Throughput
502 //
503 assert(major_cost >= 0.0, "major cost is < 0.0");
504 assert(minor_cost >= 0.0, "minor cost is < 0.0");
505 // Try to reduce the GC times.
506 if (is_full_gc) {
507 set_decide_at_full_gc(decide_at_full_gc_true);
508 adjust_promo_for_throughput(is_full_gc, &desired_promo_size);
509 }
510 } else {
511
512 // Be conservative about reducing the footprint.
513 // Do a minimum number of major collections first.
514 // Have reasonable averages for major and minor collections costs.
515 if (UseAdaptiveSizePolicyFootprintGoal &&
516 young_gen_policy_is_ready() &&
517 avg_major_gc_cost()->average() >= 0.0 &&
518 avg_minor_gc_cost()->average() >= 0.0) {
519 if (is_full_gc) {
520 set_decide_at_full_gc(decide_at_full_gc_true);
521 size_t desired_sum = desired_eden_size + desired_promo_size;
522 desired_promo_size = adjust_promo_for_footprint(desired_promo_size, desired_sum);
523 }
524 }
525 }
526
527 // Note we make the same tests as in the code block below; the code
528 // seems a little easier to read with the printing in another block.
529 if (desired_promo_size > promo_limit) {
530 // "free_in_old_gen" was the original value for used for promo_limit
531 size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
532 log_debug(gc, ergo)(
533 "PSAdaptiveSizePolicy::compute_old_gen_free_space limits:"
534 " desired_promo_size: " SIZE_FORMAT
535 " promo_limit: " SIZE_FORMAT
536 " free_in_old_gen: " SIZE_FORMAT
537 " max_old_gen_size: " SIZE_FORMAT
538 " avg_old_live: " SIZE_FORMAT,
539 desired_promo_size, promo_limit, free_in_old_gen,
540 max_old_gen_size, (size_t) avg_old_live()->average());
541 }
542 if (gc_cost() > gc_cost_limit) {
543 log_debug(gc, ergo)(
544 "PSAdaptiveSizePolicy::compute_old_gen_free_space: gc time limit"
545 " gc_cost: %f "
546 " GCTimeLimit: " UINTX_FORMAT,
547 gc_cost(), GCTimeLimit);
548 }
549
550 // Align everything and make a final limit check
551 desired_promo_size = align_size_up(desired_promo_size, _space_alignment);
552 desired_promo_size = MAX2(desired_promo_size, _space_alignment);
553
554 promo_limit = align_size_down(promo_limit, _space_alignment);
555
556 // And one last limit check, now that we've aligned things.
557 desired_promo_size = MIN2(desired_promo_size, promo_limit);
558
559 // Timing stats
560 log_debug(gc, ergo)("PSAdaptiveSizePolicy::compute_old_gen_free_space: costs minor_time: %f major_cost: %f mutator_cost: %f throughput_goal: %f",
561 minor_gc_cost(), major_gc_cost(), mutator_cost(), _throughput_goal);
562
563 log_trace(gc, ergo)("Minor_pause: %f major_pause: %f minor_interval: %f major_interval: %f pause_goal: %f",
564 _avg_minor_pause->padded_average(),
565 _avg_major_pause->padded_average(),
566 _avg_minor_interval->average(),
567 _avg_major_interval->average(),
568 gc_pause_goal_sec());
569
570 // Footprint stats
571 log_debug(gc, ergo)("Live_space: " SIZE_FORMAT " free_space: " SIZE_FORMAT,
572 live_space(), free_space());
573
574 log_trace(gc, ergo)("Base_footprint: " SIZE_FORMAT " avg_young_live: " SIZE_FORMAT " avg_old_live: " SIZE_FORMAT,
575 (size_t)_avg_base_footprint->average(),
576 (size_t)avg_young_live()->average(),
577 (size_t)avg_old_live()->average());
578
579 log_debug(gc, ergo)("Old promo_size: " SIZE_FORMAT " desired_promo_size: " SIZE_FORMAT,
580 _promo_size, desired_promo_size);
581
582 set_promo_size(desired_promo_size);
583 }
584
585 void PSAdaptiveSizePolicy::decay_supplemental_growth(bool is_full_gc) {
586 // Decay the supplemental increment? Decay the supplement growth
587 // factor even if it is not used. It is only meant to give a boost
588 // to the initial growth and if it is not used, then it was not
589 // needed.
590 if (is_full_gc) {
591 // Don't wait for the threshold value for the major collections. If
592 // here, the supplemental growth term was used and should decay.
593 if ((_avg_major_pause->count() % TenuredGenerationSizeSupplementDecay)
594 == 0) {
595 _old_gen_size_increment_supplement =
596 _old_gen_size_increment_supplement >> 1;
597 }
598 } else {
599 if ((_avg_minor_pause->count() >= AdaptiveSizePolicyReadyThreshold) &&
600 (_avg_minor_pause->count() % YoungGenerationSizeSupplementDecay) == 0) {
601 _young_gen_size_increment_supplement =
602 _young_gen_size_increment_supplement >> 1;
603 }
604 }
605 }
606
607 void PSAdaptiveSizePolicy::adjust_eden_for_minor_pause_time(bool is_full_gc,
608 size_t* desired_eden_size_ptr) {
609
610 // Adjust the young generation size to reduce pause time of
611 // of collections.
612 //
613 // The AdaptiveSizePolicyInitializingSteps test is not used
614 // here. It has not seemed to be needed but perhaps should
615 // be added for consistency.
616 if (minor_pause_young_estimator()->decrement_will_decrease()) {
617 // reduce eden size
618 set_change_young_gen_for_min_pauses(
619 decrease_young_gen_for_min_pauses_true);
620 *desired_eden_size_ptr = *desired_eden_size_ptr -
621 eden_decrement_aligned_down(*desired_eden_size_ptr);
622 } else {
623 // EXPERIMENTAL ADJUSTMENT
624 // Only record that the estimator indicated such an action.
625 // *desired_eden_size_ptr = *desired_eden_size_ptr + eden_heap_delta;
626 set_change_young_gen_for_min_pauses(
627 increase_young_gen_for_min_pauses_true);
628 }
629 }
630
631 void PSAdaptiveSizePolicy::adjust_promo_for_pause_time(bool is_full_gc,
632 size_t* desired_promo_size_ptr,
633 size_t* desired_eden_size_ptr) {
634
635 size_t promo_heap_delta = 0;
636 // Add some checks for a threshold for a change. For example,
637 // a change less than the required alignment is probably not worth
638 // attempting.
639
640 if (_avg_minor_pause->padded_average() <= _avg_major_pause->padded_average() && is_full_gc) {
641 // Adjust for the major pause time only at full gc's because the
642 // affects of a change can only be seen at full gc's.
643
644 // Reduce old generation size to reduce pause?
645 if (major_pause_old_estimator()->decrement_will_decrease()) {
646 // reduce old generation size
647 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true);
648 promo_heap_delta = promo_decrement_aligned_down(*desired_promo_size_ptr);
649 *desired_promo_size_ptr = _promo_size - promo_heap_delta;
650 } else {
651 // EXPERIMENTAL ADJUSTMENT
652 // Only record that the estimator indicated such an action.
653 // *desired_promo_size_ptr = _promo_size +
654 // promo_increment_aligned_up(*desired_promo_size_ptr);
655 set_change_old_gen_for_maj_pauses(increase_old_gen_for_maj_pauses_true);
656 }
657 }
658
659 log_trace(gc, ergo)(
660 "PSAdaptiveSizePolicy::adjust_promo_for_pause_time "
661 "adjusting gen sizes for major pause (avg %f goal %f). "
662 "desired_promo_size " SIZE_FORMAT " promo delta " SIZE_FORMAT,
663 _avg_major_pause->average(), gc_pause_goal_sec(),
664 *desired_promo_size_ptr, promo_heap_delta);
665 }
666
667 void PSAdaptiveSizePolicy::adjust_eden_for_pause_time(bool is_full_gc,
668 size_t* desired_promo_size_ptr,
669 size_t* desired_eden_size_ptr) {
670
671 size_t eden_heap_delta = 0;
672 // Add some checks for a threshold for a change. For example,
673 // a change less than the required alignment is probably not worth
674 // attempting.
675 if (_avg_minor_pause->padded_average() > _avg_major_pause->padded_average()) {
676 adjust_eden_for_minor_pause_time(is_full_gc, desired_eden_size_ptr);
677 }
678 log_trace(gc, ergo)(
679 "PSAdaptiveSizePolicy::adjust_eden_for_pause_time "
680 "adjusting gen sizes for major pause (avg %f goal %f). "
681 "desired_eden_size " SIZE_FORMAT " eden delta " SIZE_FORMAT,
682 _avg_major_pause->average(), gc_pause_goal_sec(),
683 *desired_eden_size_ptr, eden_heap_delta);
684 }
685
686 void PSAdaptiveSizePolicy::adjust_promo_for_throughput(bool is_full_gc,
687 size_t* desired_promo_size_ptr) {
688
689 // Add some checks for a threshold for a change. For example,
690 // a change less than the required alignment is probably not worth
691 // attempting.
692
693 if ((gc_cost() + mutator_cost()) == 0.0) {
694 return;
695 }
696
697 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",
698 is_full_gc,
699 *desired_promo_size_ptr,
700 mutator_cost(),
701 major_gc_cost(),
702 minor_gc_cost());
703
704 // Tenured generation
705 if (is_full_gc) {
706 // Calculate the change to use for the tenured gen.
707 size_t scaled_promo_heap_delta = 0;
708 // Can the increment to the generation be scaled?
709 if (gc_cost() >= 0.0 && major_gc_cost() >= 0.0) {
710 size_t promo_heap_delta =
711 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
712 double scale_by_ratio = major_gc_cost() / gc_cost();
713 scaled_promo_heap_delta =
714 (size_t) (scale_by_ratio * (double) promo_heap_delta);
715 log_trace(gc, ergo)("Scaled tenured increment: " SIZE_FORMAT " by %f down to " SIZE_FORMAT,
716 promo_heap_delta, scale_by_ratio, scaled_promo_heap_delta);
717 } else if (major_gc_cost() >= 0.0) {
718 // Scaling is not going to work. If the major gc time is the
719 // larger, give it a full increment.
720 if (major_gc_cost() >= minor_gc_cost()) {
721 scaled_promo_heap_delta =
722 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
723 }
724 } else {
725 // Don't expect to get here but it's ok if it does
726 // in the product build since the delta will be 0
727 // and nothing will change.
728 assert(false, "Unexpected value for gc costs");
729 }
730
731 switch (AdaptiveSizeThroughPutPolicy) {
732 case 1:
733 // Early in the run the statistics might not be good. Until
734 // a specific number of collections have been, use the heuristic
735 // that a larger generation size means lower collection costs.
736 if (major_collection_estimator()->increment_will_decrease() ||
737 (_old_gen_change_for_major_throughput
738 <= AdaptiveSizePolicyInitializingSteps)) {
739 // Increase tenured generation size to reduce major collection cost
740 if ((*desired_promo_size_ptr + scaled_promo_heap_delta) >
741 *desired_promo_size_ptr) {
742 *desired_promo_size_ptr = _promo_size + scaled_promo_heap_delta;
743 }
744 set_change_old_gen_for_throughput(
745 increase_old_gen_for_throughput_true);
746 _old_gen_change_for_major_throughput++;
747 } else {
748 // EXPERIMENTAL ADJUSTMENT
749 // Record that decreasing the old gen size would decrease
750 // the major collection cost but don't do it.
751 // *desired_promo_size_ptr = _promo_size -
752 // promo_decrement_aligned_down(*desired_promo_size_ptr);
753 set_change_old_gen_for_throughput(
754 decrease_old_gen_for_throughput_true);
755 }
756
757 break;
758 default:
759 // Simplest strategy
760 if ((*desired_promo_size_ptr + scaled_promo_heap_delta) >
761 *desired_promo_size_ptr) {
762 *desired_promo_size_ptr = *desired_promo_size_ptr +
763 scaled_promo_heap_delta;
764 }
765 set_change_old_gen_for_throughput(
766 increase_old_gen_for_throughput_true);
767 _old_gen_change_for_major_throughput++;
768 }
769
770 log_trace(gc, ergo)("Adjusting tenured gen for throughput (avg %f goal %f). desired_promo_size " SIZE_FORMAT " promo_delta " SIZE_FORMAT ,
771 mutator_cost(),
772 _throughput_goal,
773 *desired_promo_size_ptr, scaled_promo_heap_delta);
774 }
775 }
776
777 void PSAdaptiveSizePolicy::adjust_eden_for_throughput(bool is_full_gc,
778 size_t* desired_eden_size_ptr) {
779
780 // Add some checks for a threshold for a change. For example,
781 // a change less than the required alignment is probably not worth
782 // attempting.
783
784 if ((gc_cost() + mutator_cost()) == 0.0) {
785 return;
786 }
787
788 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",
789 is_full_gc,
790 *desired_eden_size_ptr,
791 mutator_cost(),
792 major_gc_cost(),
793 minor_gc_cost());
794
795 // Young generation
796 size_t scaled_eden_heap_delta = 0;
797 // Can the increment to the generation be scaled?
798 if (gc_cost() >= 0.0 && minor_gc_cost() >= 0.0) {
799 size_t eden_heap_delta =
800 eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr);
801 double scale_by_ratio = minor_gc_cost() / gc_cost();
802 assert(scale_by_ratio <= 1.0 && scale_by_ratio >= 0.0, "Scaling is wrong");
803 scaled_eden_heap_delta =
804 (size_t) (scale_by_ratio * (double) eden_heap_delta);
805 log_trace(gc, ergo)("Scaled eden increment: " SIZE_FORMAT " by %f down to " SIZE_FORMAT,
806 eden_heap_delta, scale_by_ratio, scaled_eden_heap_delta);
807 } else if (minor_gc_cost() >= 0.0) {
808 // Scaling is not going to work. If the minor gc time is the
809 // larger, give it a full increment.
810 if (minor_gc_cost() > major_gc_cost()) {
811 scaled_eden_heap_delta =
812 eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr);
813 }
814 } else {
815 // Don't expect to get here but it's ok if it does
816 // in the product build since the delta will be 0
817 // and nothing will change.
818 assert(false, "Unexpected value for gc costs");
819 }
820
821 // Use a heuristic for some number of collections to give
822 // the averages time to settle down.
823 switch (AdaptiveSizeThroughPutPolicy) {
824 case 1:
825 if (minor_collection_estimator()->increment_will_decrease() ||
826 (_young_gen_change_for_minor_throughput
827 <= AdaptiveSizePolicyInitializingSteps)) {
828 // Expand young generation size to reduce frequency of
829 // of collections.
830 if ((*desired_eden_size_ptr + scaled_eden_heap_delta) >
831 *desired_eden_size_ptr) {
832 *desired_eden_size_ptr =
833 *desired_eden_size_ptr + scaled_eden_heap_delta;
834 }
835 set_change_young_gen_for_throughput(
836 increase_young_gen_for_througput_true);
837 _young_gen_change_for_minor_throughput++;
838 } else {
839 // EXPERIMENTAL ADJUSTMENT
840 // Record that decreasing the young gen size would decrease
841 // the minor collection cost but don't do it.
842 // *desired_eden_size_ptr = _eden_size -
843 // eden_decrement_aligned_down(*desired_eden_size_ptr);
844 set_change_young_gen_for_throughput(
845 decrease_young_gen_for_througput_true);
846 }
847 break;
848 default:
849 if ((*desired_eden_size_ptr + scaled_eden_heap_delta) >
850 *desired_eden_size_ptr) {
851 *desired_eden_size_ptr =
852 *desired_eden_size_ptr + scaled_eden_heap_delta;
853 }
854 set_change_young_gen_for_throughput(
855 increase_young_gen_for_througput_true);
856 _young_gen_change_for_minor_throughput++;
857 }
858
859 log_trace(gc, ergo)("Adjusting eden for throughput (avg %f goal %f). desired_eden_size " SIZE_FORMAT " eden delta " SIZE_FORMAT,
860 mutator_cost(), _throughput_goal, *desired_eden_size_ptr, scaled_eden_heap_delta);
861 }
862
863 size_t PSAdaptiveSizePolicy::adjust_promo_for_footprint(
864 size_t desired_promo_size, size_t desired_sum) {
865 assert(desired_promo_size <= desired_sum, "Inconsistent parameters");
866 set_decrease_for_footprint(decrease_old_gen_for_footprint_true);
867
868 size_t change = promo_decrement(desired_promo_size);
869 change = scale_down(change, desired_promo_size, desired_sum);
870
871 size_t reduced_size = desired_promo_size - change;
872
873 log_trace(gc, ergo)(
874 "AdaptiveSizePolicy::adjust_promo_for_footprint "
875 "adjusting tenured gen for footprint. "
876 "starting promo size " SIZE_FORMAT
877 " reduced promo size " SIZE_FORMAT
878 " promo delta " SIZE_FORMAT,
879 desired_promo_size, reduced_size, change );
880
881 assert(reduced_size <= desired_promo_size, "Inconsistent result");
882 return reduced_size;
883 }
884
885 size_t PSAdaptiveSizePolicy::adjust_eden_for_footprint(
886 size_t desired_eden_size, size_t desired_sum) {
887 assert(desired_eden_size <= desired_sum, "Inconsistent parameters");
888 set_decrease_for_footprint(decrease_young_gen_for_footprint_true);
889
890 size_t change = eden_decrement(desired_eden_size);
891 change = scale_down(change, desired_eden_size, desired_sum);
892
893 size_t reduced_size = desired_eden_size - change;
894
895 log_trace(gc, ergo)(
896 "AdaptiveSizePolicy::adjust_eden_for_footprint "
897 "adjusting eden for footprint. "
898 " starting eden size " SIZE_FORMAT
899 " reduced eden size " SIZE_FORMAT
900 " eden delta " SIZE_FORMAT,
901 desired_eden_size, reduced_size, change);
902
903 assert(reduced_size <= desired_eden_size, "Inconsistent result");
904 return reduced_size;
905 }
906
907 // Scale down "change" by the factor
908 // part / total
909 // Don't align the results.
910
911 size_t PSAdaptiveSizePolicy::scale_down(size_t change,
912 double part,
913 double total) {
914 assert(part <= total, "Inconsistent input");
915 size_t reduced_change = change;
916 if (total > 0) {
917 double fraction = part / total;
918 reduced_change = (size_t) (fraction * (double) change);
919 }
920 assert(reduced_change <= change, "Inconsistent result");
921 return reduced_change;
922 }
923
924 size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden,
925 uint percent_change) {
926 size_t eden_heap_delta;
927 eden_heap_delta = cur_eden / 100 * percent_change;
928 return eden_heap_delta;
929 }
930
931 size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden) {
932 return eden_increment(cur_eden, YoungGenerationSizeIncrement);
933 }
934
935 size_t PSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) {
936 size_t result = eden_increment(cur_eden, YoungGenerationSizeIncrement);
937 return align_size_up(result, _space_alignment);
938 }
939
940 size_t PSAdaptiveSizePolicy::eden_increment_aligned_down(size_t cur_eden) {
941 size_t result = eden_increment(cur_eden);
942 return align_size_down(result, _space_alignment);
943 }
944
945 size_t PSAdaptiveSizePolicy::eden_increment_with_supplement_aligned_up(
946 size_t cur_eden) {
947 size_t result = eden_increment(cur_eden,
948 YoungGenerationSizeIncrement + _young_gen_size_increment_supplement);
949 return align_size_up(result, _space_alignment);
950 }
951
952 size_t PSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) {
953 size_t eden_heap_delta = eden_decrement(cur_eden);
954 return align_size_down(eden_heap_delta, _space_alignment);
955 }
956
957 size_t PSAdaptiveSizePolicy::eden_decrement(size_t cur_eden) {
958 size_t eden_heap_delta = eden_increment(cur_eden) /
959 AdaptiveSizeDecrementScaleFactor;
960 return eden_heap_delta;
961 }
962
963 size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo,
964 uint percent_change) {
965 size_t promo_heap_delta;
966 promo_heap_delta = cur_promo / 100 * percent_change;
967 return promo_heap_delta;
968 }
969
970 size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo) {
971 return promo_increment(cur_promo, TenuredGenerationSizeIncrement);
972 }
973
974 size_t PSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) {
975 size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement);
976 return align_size_up(result, _space_alignment);
977 }
978
979 size_t PSAdaptiveSizePolicy::promo_increment_aligned_down(size_t cur_promo) {
980 size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement);
981 return align_size_down(result, _space_alignment);
982 }
983
984 size_t PSAdaptiveSizePolicy::promo_increment_with_supplement_aligned_up(
985 size_t cur_promo) {
986 size_t result = promo_increment(cur_promo,
987 TenuredGenerationSizeIncrement + _old_gen_size_increment_supplement);
988 return align_size_up(result, _space_alignment);
989 }
990
991 size_t PSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) {
992 size_t promo_heap_delta = promo_decrement(cur_promo);
993 return align_size_down(promo_heap_delta, _space_alignment);
994 }
995
996 size_t PSAdaptiveSizePolicy::promo_decrement(size_t cur_promo) {
997 size_t promo_heap_delta = promo_increment(cur_promo);
998 promo_heap_delta = promo_heap_delta / AdaptiveSizeDecrementScaleFactor;
999 return promo_heap_delta;
1000 }
1001
1002 uint PSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold(
1003 bool is_survivor_overflow,
1004 uint tenuring_threshold,
1005 size_t survivor_limit) {
1006 assert(survivor_limit >= _space_alignment,
1007 "survivor_limit too small");
1008 assert((size_t)align_size_down(survivor_limit, _space_alignment)
1009 == survivor_limit, "survivor_limit not aligned");
1010
1011 // This method is called even if the tenuring threshold and survivor
1012 // spaces are not adjusted so that the averages are sampled above.
1013 if (!UsePSAdaptiveSurvivorSizePolicy ||
1014 !young_gen_policy_is_ready()) {
1015 return tenuring_threshold;
1016 }
1017
1018 // We'll decide whether to increase or decrease the tenuring
1019 // threshold based partly on the newly computed survivor size
1020 // (if we hit the maximum limit allowed, we'll always choose to
1021 // decrement the threshold).
1022 bool incr_tenuring_threshold = false;
1023 bool decr_tenuring_threshold = false;
1024
1025 set_decrement_tenuring_threshold_for_gc_cost(false);
1026 set_increment_tenuring_threshold_for_gc_cost(false);
1027 set_decrement_tenuring_threshold_for_survivor_limit(false);
1028
1029 if (!is_survivor_overflow) {
1030 // Keep running averages on how much survived
1031
1032 // We use the tenuring threshold to equalize the cost of major
1033 // and minor collections.
1034 // ThresholdTolerance is used to indicate how sensitive the
1035 // tenuring threshold is to differences in cost between the
1036 // collection types.
1037
1038 // Get the times of interest. This involves a little work, so
1039 // we cache the values here.
1040 const double major_cost = major_gc_cost();
1041 const double minor_cost = minor_gc_cost();
1042
1043 if (minor_cost > major_cost * _threshold_tolerance_percent) {
1044 // Minor times are getting too long; lower the threshold so
1045 // less survives and more is promoted.
1046 decr_tenuring_threshold = true;
1047 set_decrement_tenuring_threshold_for_gc_cost(true);
1048 } else if (major_cost > minor_cost * _threshold_tolerance_percent) {
1049 // Major times are too long, so we want less promotion.
1050 incr_tenuring_threshold = true;
1051 set_increment_tenuring_threshold_for_gc_cost(true);
1052 }
1053
1054 } else {
1055 // Survivor space overflow occurred, so promoted and survived are
1056 // not accurate. We'll make our best guess by combining survived
1057 // and promoted and count them as survivors.
1058 //
1059 // We'll lower the tenuring threshold to see if we can correct
1060 // things. Also, set the survivor size conservatively. We're
1061 // trying to avoid many overflows from occurring if defnew size
1062 // is just too small.
1063
1064 decr_tenuring_threshold = true;
1065 }
1066
1067 // The padded average also maintains a deviation from the average;
1068 // we use this to see how good of an estimate we have of what survived.
1069 // We're trying to pad the survivor size as little as possible without
1070 // overflowing the survivor spaces.
1071 size_t target_size = align_size_up((size_t)_avg_survived->padded_average(),
1072 _space_alignment);
1073 target_size = MAX2(target_size, _space_alignment);
1074
1075 if (target_size > survivor_limit) {
1076 // Target size is bigger than we can handle. Let's also reduce
1077 // the tenuring threshold.
1078 target_size = survivor_limit;
1079 decr_tenuring_threshold = true;
1080 set_decrement_tenuring_threshold_for_survivor_limit(true);
1081 }
1082
1083 // Finally, increment or decrement the tenuring threshold, as decided above.
1084 // We test for decrementing first, as we might have hit the target size
1085 // limit.
1086 if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1087 if (tenuring_threshold > 1) {
1088 tenuring_threshold--;
1089 }
1090 } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1091 if (tenuring_threshold < MaxTenuringThreshold) {
1092 tenuring_threshold++;
1093 }
1094 }
1095
1096 // We keep a running average of the amount promoted which is used
1097 // to decide when we should collect the old generation (when
1098 // the amount of old gen free space is less than what we expect to
1099 // promote).
1100
1101 log_trace(gc, ergo)("avg_survived: %f avg_deviation: %f", _avg_survived->average(), _avg_survived->deviation());
1102 log_debug(gc, ergo)("avg_survived_padded_avg: %f", _avg_survived->padded_average());
1103
1104 log_trace(gc, ergo)("avg_promoted_avg: %f avg_promoted_dev: %f", avg_promoted()->average(), avg_promoted()->deviation());
1105 log_debug(gc, ergo)("avg_promoted_padded_avg: %f avg_pretenured_padded_avg: %f tenuring_thresh: %d target_size: " SIZE_FORMAT,
1106 avg_promoted()->padded_average(),
1107 _avg_pretenured->padded_average(),
1108 tenuring_threshold, target_size);
1109
1110 set_survivor_size(target_size);
1111
1112 return tenuring_threshold;
1113 }
1114
1115 void PSAdaptiveSizePolicy::update_averages(bool is_survivor_overflow,
1116 size_t survived,
1117 size_t promoted) {
1118 // Update averages
1119 if (!is_survivor_overflow) {
1120 // Keep running averages on how much survived
1121 _avg_survived->sample(survived);
1122 } else {
1123 size_t survived_guess = survived + promoted;
1124 _avg_survived->sample(survived_guess);
1125 }
1126 avg_promoted()->sample(promoted);
1127
1128 log_trace(gc, ergo)("AdaptiveSizePolicy::update_averages: survived: " SIZE_FORMAT " promoted: " SIZE_FORMAT " overflow: %s",
1129 survived, promoted, is_survivor_overflow ? "true" : "false");
1130 }
1131
1132 bool PSAdaptiveSizePolicy::print() const {
1133
1134 if (!UseAdaptiveSizePolicy) {
1135 return false;
1136 }
1137
1138 if (AdaptiveSizePolicy::print()) {
1139 AdaptiveSizePolicy::print_tenuring_threshold(PSScavenge::tenuring_threshold());
1140 return true;
1141 }
1142
1143 return false;
1144 }
1145
1146 #ifndef PRODUCT
1147
1148 void TestOldFreeSpaceCalculation_test() {
1149 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 20) == 25, "Calculation of free memory failed");
1150 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 50) == 100, "Calculation of free memory failed");
1151 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 60) == 150, "Calculation of free memory failed");
1152 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 75) == 300, "Calculation of free memory failed");
1153 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 20) == 100, "Calculation of free memory failed");
1154 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 50) == 400, "Calculation of free memory failed");
1155 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 60) == 600, "Calculation of free memory failed");
1156 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 75) == 1200, "Calculation of free memory failed");
1157 }
1158
1159 #endif /* !PRODUCT */