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src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.cpp@c18cbe5936b8
src/share/vm/gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.cpp
Thu, 27 May 2010 19:08:38 -0700
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6941466: Oracle rebranding changes for Hotspot repositories
Summary: Change all the Sun copyrights to Oracle copyright
Reviewed-by: ohair
1 /*
2 * Copyright (c) 2004, 2006, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24 #include "incls/_precompiled.incl"
25 #include "incls/_cmsAdaptiveSizePolicy.cpp.incl"
27 elapsedTimer CMSAdaptiveSizePolicy::_concurrent_timer;
28 elapsedTimer CMSAdaptiveSizePolicy::_STW_timer;
30 // Defined if the granularity of the time measurements is potentially too large.
31 #define CLOCK_GRANULARITY_TOO_LARGE
33 CMSAdaptiveSizePolicy::CMSAdaptiveSizePolicy(size_t init_eden_size,
34 size_t init_promo_size,
35 size_t init_survivor_size,
36 double max_gc_minor_pause_sec,
37 double max_gc_pause_sec,
38 uint gc_cost_ratio) :
39 AdaptiveSizePolicy(init_eden_size,
40 init_promo_size,
41 init_survivor_size,
42 max_gc_pause_sec,
43 gc_cost_ratio) {
45 clear_internal_time_intervals();
47 _processor_count = os::active_processor_count();
49 if (CMSConcurrentMTEnabled && (ConcGCThreads > 1)) {
50 assert(_processor_count > 0, "Processor count is suspect");
51 _concurrent_processor_count = MIN2((uint) ConcGCThreads,
52 (uint) _processor_count);
53 } else {
54 _concurrent_processor_count = 1;
55 }
57 _avg_concurrent_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
58 _avg_concurrent_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
59 _avg_concurrent_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
61 _avg_initial_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight,
62 PausePadding);
63 _avg_remark_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight,
64 PausePadding);
66 _avg_cms_STW_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
67 _avg_cms_STW_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
69 _avg_cms_free = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
70 _avg_cms_free_at_sweep = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
71 _avg_cms_promo = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
73 // Mark-sweep-compact
74 _avg_msc_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
75 _avg_msc_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
76 _avg_msc_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
78 // Mark-sweep
79 _avg_ms_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
80 _avg_ms_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
81 _avg_ms_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
83 // Variables that estimate pause times as a function of generation
84 // size.
85 _remark_pause_old_estimator =
86 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
87 _initial_pause_old_estimator =
88 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
89 _remark_pause_young_estimator =
90 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
91 _initial_pause_young_estimator =
92 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
94 // Alignment comes from that used in ReservedSpace.
95 _generation_alignment = os::vm_allocation_granularity();
97 // Start the concurrent timer here so that the first
98 // concurrent_phases_begin() measures a finite mutator
99 // time. A finite mutator time is used to determine
100 // if a concurrent collection has been started. If this
101 // proves to be a problem, use some explicit flag to
102 // signal that a concurrent collection has been started.
103 _concurrent_timer.start();
104 _STW_timer.start();
105 }
107 double CMSAdaptiveSizePolicy::concurrent_processor_fraction() {
108 // For now assume no other daemon threads are taking alway
109 // cpu's from the application.
110 return ((double) _concurrent_processor_count / (double) _processor_count);
111 }
113 double CMSAdaptiveSizePolicy::concurrent_collection_cost(
114 double interval_in_seconds) {
115 // When the precleaning and sweeping phases use multiple
116 // threads, change one_processor_fraction to
117 // concurrent_processor_fraction().
118 double one_processor_fraction = 1.0 / ((double) processor_count());
119 double concurrent_cost =
120 collection_cost(_latest_cms_concurrent_marking_time_secs,
121 interval_in_seconds) * concurrent_processor_fraction() +
122 collection_cost(_latest_cms_concurrent_precleaning_time_secs,
123 interval_in_seconds) * one_processor_fraction +
124 collection_cost(_latest_cms_concurrent_sweeping_time_secs,
125 interval_in_seconds) * one_processor_fraction;
126 if (PrintAdaptiveSizePolicy && Verbose) {
127 gclog_or_tty->print_cr(
128 "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_cost(%f) "
129 "_latest_cms_concurrent_marking_cost %f "
130 "_latest_cms_concurrent_precleaning_cost %f "
131 "_latest_cms_concurrent_sweeping_cost %f "
132 "concurrent_processor_fraction %f "
133 "concurrent_cost %f ",
134 interval_in_seconds,
135 collection_cost(_latest_cms_concurrent_marking_time_secs,
136 interval_in_seconds),
137 collection_cost(_latest_cms_concurrent_precleaning_time_secs,
138 interval_in_seconds),
139 collection_cost(_latest_cms_concurrent_sweeping_time_secs,
140 interval_in_seconds),
141 concurrent_processor_fraction(),
142 concurrent_cost);
143 }
144 return concurrent_cost;
145 }
147 double CMSAdaptiveSizePolicy::concurrent_collection_time() {
148 double latest_cms_sum_concurrent_phases_time_secs =
149 _latest_cms_concurrent_marking_time_secs +
150 _latest_cms_concurrent_precleaning_time_secs +
151 _latest_cms_concurrent_sweeping_time_secs;
152 return latest_cms_sum_concurrent_phases_time_secs;
153 }
155 double CMSAdaptiveSizePolicy::scaled_concurrent_collection_time() {
156 // When the precleaning and sweeping phases use multiple
157 // threads, change one_processor_fraction to
158 // concurrent_processor_fraction().
159 double one_processor_fraction = 1.0 / ((double) processor_count());
160 double latest_cms_sum_concurrent_phases_time_secs =
161 _latest_cms_concurrent_marking_time_secs * concurrent_processor_fraction() +
162 _latest_cms_concurrent_precleaning_time_secs * one_processor_fraction +
163 _latest_cms_concurrent_sweeping_time_secs * one_processor_fraction ;
164 if (PrintAdaptiveSizePolicy && Verbose) {
165 gclog_or_tty->print_cr(
166 "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_time "
167 "_latest_cms_concurrent_marking_time_secs %f "
168 "_latest_cms_concurrent_precleaning_time_secs %f "
169 "_latest_cms_concurrent_sweeping_time_secs %f "
170 "concurrent_processor_fraction %f "
171 "latest_cms_sum_concurrent_phases_time_secs %f ",
172 _latest_cms_concurrent_marking_time_secs,
173 _latest_cms_concurrent_precleaning_time_secs,
174 _latest_cms_concurrent_sweeping_time_secs,
175 concurrent_processor_fraction(),
176 latest_cms_sum_concurrent_phases_time_secs);
177 }
178 return latest_cms_sum_concurrent_phases_time_secs;
179 }
181 void CMSAdaptiveSizePolicy::update_minor_pause_old_estimator(
182 double minor_pause_in_ms) {
183 // Get the equivalent of the free space
184 // that is available for promotions in the CMS generation
185 // and use that to update _minor_pause_old_estimator
187 // Don't implement this until it is needed. A warning is
188 // printed if _minor_pause_old_estimator is used.
189 }
191 void CMSAdaptiveSizePolicy::concurrent_marking_begin() {
192 if (PrintAdaptiveSizePolicy && Verbose) {
193 gclog_or_tty->print(" ");
194 gclog_or_tty->stamp();
195 gclog_or_tty->print(": concurrent_marking_begin ");
196 }
197 // Update the interval time
198 _concurrent_timer.stop();
199 _latest_cms_collection_end_to_collection_start_secs = _concurrent_timer.seconds();
200 if (PrintAdaptiveSizePolicy && Verbose) {
201 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_begin: "
202 "mutator time %f", _latest_cms_collection_end_to_collection_start_secs);
203 }
204 _concurrent_timer.reset();
205 _concurrent_timer.start();
206 }
208 void CMSAdaptiveSizePolicy::concurrent_marking_end() {
209 if (PrintAdaptiveSizePolicy && Verbose) {
210 gclog_or_tty->stamp();
211 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_end()");
212 }
214 _concurrent_timer.stop();
215 _latest_cms_concurrent_marking_time_secs = _concurrent_timer.seconds();
217 if (PrintAdaptiveSizePolicy && Verbose) {
218 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_marking_end"
219 ":concurrent marking time (s) %f",
220 _latest_cms_concurrent_marking_time_secs);
221 }
222 }
224 void CMSAdaptiveSizePolicy::concurrent_precleaning_begin() {
225 if (PrintAdaptiveSizePolicy && Verbose) {
226 gclog_or_tty->stamp();
227 gclog_or_tty->print_cr(
228 "CMSAdaptiveSizePolicy::concurrent_precleaning_begin()");
229 }
230 _concurrent_timer.reset();
231 _concurrent_timer.start();
232 }
235 void CMSAdaptiveSizePolicy::concurrent_precleaning_end() {
236 if (PrintAdaptiveSizePolicy && Verbose) {
237 gclog_or_tty->stamp();
238 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_precleaning_end()");
239 }
241 _concurrent_timer.stop();
242 // May be set again by a second call during the same collection.
243 _latest_cms_concurrent_precleaning_time_secs = _concurrent_timer.seconds();
245 if (PrintAdaptiveSizePolicy && Verbose) {
246 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_precleaning_end"
247 ":concurrent precleaning time (s) %f",
248 _latest_cms_concurrent_precleaning_time_secs);
249 }
250 }
252 void CMSAdaptiveSizePolicy::concurrent_sweeping_begin() {
253 if (PrintAdaptiveSizePolicy && Verbose) {
254 gclog_or_tty->stamp();
255 gclog_or_tty->print_cr(
256 "CMSAdaptiveSizePolicy::concurrent_sweeping_begin()");
257 }
258 _concurrent_timer.reset();
259 _concurrent_timer.start();
260 }
263 void CMSAdaptiveSizePolicy::concurrent_sweeping_end() {
264 if (PrintAdaptiveSizePolicy && Verbose) {
265 gclog_or_tty->stamp();
266 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_sweeping_end()");
267 }
269 _concurrent_timer.stop();
270 _latest_cms_concurrent_sweeping_time_secs = _concurrent_timer.seconds();
272 if (PrintAdaptiveSizePolicy && Verbose) {
273 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_sweeping_end"
274 ":concurrent sweeping time (s) %f",
275 _latest_cms_concurrent_sweeping_time_secs);
276 }
277 }
279 void CMSAdaptiveSizePolicy::concurrent_phases_end(GCCause::Cause gc_cause,
280 size_t cur_eden,
281 size_t cur_promo) {
282 if (PrintAdaptiveSizePolicy && Verbose) {
283 gclog_or_tty->print(" ");
284 gclog_or_tty->stamp();
285 gclog_or_tty->print(": concurrent_phases_end ");
286 }
288 // Update the concurrent timer
289 _concurrent_timer.stop();
291 if (gc_cause != GCCause::_java_lang_system_gc ||
292 UseAdaptiveSizePolicyWithSystemGC) {
294 avg_cms_free()->sample(cur_promo);
295 double latest_cms_sum_concurrent_phases_time_secs =
296 concurrent_collection_time();
298 _avg_concurrent_time->sample(latest_cms_sum_concurrent_phases_time_secs);
300 // Cost of collection (unit-less)
302 // Total interval for collection. May not be valid. Tests
303 // below determine whether to use this.
304 //
305 if (PrintAdaptiveSizePolicy && Verbose) {
306 gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::concurrent_phases_end \n"
307 "_latest_cms_reset_end_to_initial_mark_start_secs %f \n"
308 "_latest_cms_initial_mark_start_to_end_time_secs %f \n"
309 "_latest_cms_remark_start_to_end_time_secs %f \n"
310 "_latest_cms_concurrent_marking_time_secs %f \n"
311 "_latest_cms_concurrent_precleaning_time_secs %f \n"
312 "_latest_cms_concurrent_sweeping_time_secs %f \n"
313 "latest_cms_sum_concurrent_phases_time_secs %f \n"
314 "_latest_cms_collection_end_to_collection_start_secs %f \n"
315 "concurrent_processor_fraction %f",
316 _latest_cms_reset_end_to_initial_mark_start_secs,
317 _latest_cms_initial_mark_start_to_end_time_secs,
318 _latest_cms_remark_start_to_end_time_secs,
319 _latest_cms_concurrent_marking_time_secs,
320 _latest_cms_concurrent_precleaning_time_secs,
321 _latest_cms_concurrent_sweeping_time_secs,
322 latest_cms_sum_concurrent_phases_time_secs,
323 _latest_cms_collection_end_to_collection_start_secs,
324 concurrent_processor_fraction());
325 }
326 double interval_in_seconds =
327 _latest_cms_initial_mark_start_to_end_time_secs +
328 _latest_cms_remark_start_to_end_time_secs +
329 latest_cms_sum_concurrent_phases_time_secs +
330 _latest_cms_collection_end_to_collection_start_secs;
331 assert(interval_in_seconds >= 0.0,
332 "Bad interval between cms collections");
334 // Sample for performance counter
335 avg_concurrent_interval()->sample(interval_in_seconds);
337 // STW costs (initial and remark pauses)
338 // Cost of collection (unit-less)
339 assert(_latest_cms_initial_mark_start_to_end_time_secs >= 0.0,
340 "Bad initial mark pause");
341 assert(_latest_cms_remark_start_to_end_time_secs >= 0.0,
342 "Bad remark pause");
343 double STW_time_in_seconds =
344 _latest_cms_initial_mark_start_to_end_time_secs +
345 _latest_cms_remark_start_to_end_time_secs;
346 double STW_collection_cost = 0.0;
347 if (interval_in_seconds > 0.0) {
348 // cost for the STW phases of the concurrent collection.
349 STW_collection_cost = STW_time_in_seconds / interval_in_seconds;
350 avg_cms_STW_gc_cost()->sample(STW_collection_cost);
351 }
352 if (PrintAdaptiveSizePolicy && Verbose) {
353 gclog_or_tty->print("cmsAdaptiveSizePolicy::STW_collection_end: "
354 "STW gc cost: %f average: %f", STW_collection_cost,
355 avg_cms_STW_gc_cost()->average());
356 gclog_or_tty->print_cr(" STW pause: %f (ms) STW period %f (ms)",
357 (double) STW_time_in_seconds * MILLIUNITS,
358 (double) interval_in_seconds * MILLIUNITS);
359 }
361 double concurrent_cost = 0.0;
362 if (latest_cms_sum_concurrent_phases_time_secs > 0.0) {
363 concurrent_cost = concurrent_collection_cost(interval_in_seconds);
365 avg_concurrent_gc_cost()->sample(concurrent_cost);
366 // Average this ms cost into all the other types gc costs
368 if (PrintAdaptiveSizePolicy && Verbose) {
369 gclog_or_tty->print("cmsAdaptiveSizePolicy::concurrent_phases_end: "
370 "concurrent gc cost: %f average: %f",
371 concurrent_cost,
372 _avg_concurrent_gc_cost->average());
373 gclog_or_tty->print_cr(" concurrent time: %f (ms) cms period %f (ms)"
374 " processor fraction: %f",
375 latest_cms_sum_concurrent_phases_time_secs * MILLIUNITS,
376 interval_in_seconds * MILLIUNITS,
377 concurrent_processor_fraction());
378 }
379 }
380 double total_collection_cost = STW_collection_cost + concurrent_cost;
381 avg_major_gc_cost()->sample(total_collection_cost);
383 // Gather information for estimating future behavior
384 double initial_pause_in_ms = _latest_cms_initial_mark_start_to_end_time_secs * MILLIUNITS;
385 double remark_pause_in_ms = _latest_cms_remark_start_to_end_time_secs * MILLIUNITS;
387 double cur_promo_size_in_mbytes = ((double)cur_promo)/((double)M);
388 initial_pause_old_estimator()->update(cur_promo_size_in_mbytes,
389 initial_pause_in_ms);
390 remark_pause_old_estimator()->update(cur_promo_size_in_mbytes,
391 remark_pause_in_ms);
392 major_collection_estimator()->update(cur_promo_size_in_mbytes,
393 total_collection_cost);
395 // This estimate uses the average eden size. It could also
396 // have used the latest eden size. Which is better?
397 double cur_eden_size_in_mbytes = ((double)cur_eden)/((double) M);
398 initial_pause_young_estimator()->update(cur_eden_size_in_mbytes,
399 initial_pause_in_ms);
400 remark_pause_young_estimator()->update(cur_eden_size_in_mbytes,
401 remark_pause_in_ms);
402 }
404 clear_internal_time_intervals();
406 set_first_after_collection();
408 // The concurrent phases keeps track of it's own mutator interval
409 // with this timer. This allows the stop-the-world phase to
410 // be included in the mutator time so that the stop-the-world time
411 // is not double counted. Reset and start it.
412 _concurrent_timer.reset();
413 _concurrent_timer.start();
415 // The mutator time between STW phases does not include the
416 // concurrent collection time.
417 _STW_timer.reset();
418 _STW_timer.start();
419 }
421 void CMSAdaptiveSizePolicy::checkpoint_roots_initial_begin() {
422 // Update the interval time
423 _STW_timer.stop();
424 _latest_cms_reset_end_to_initial_mark_start_secs = _STW_timer.seconds();
425 // Reset for the initial mark
426 _STW_timer.reset();
427 _STW_timer.start();
428 }
430 void CMSAdaptiveSizePolicy::checkpoint_roots_initial_end(
431 GCCause::Cause gc_cause) {
432 _STW_timer.stop();
434 if (gc_cause != GCCause::_java_lang_system_gc ||
435 UseAdaptiveSizePolicyWithSystemGC) {
436 _latest_cms_initial_mark_start_to_end_time_secs = _STW_timer.seconds();
437 avg_initial_pause()->sample(_latest_cms_initial_mark_start_to_end_time_secs);
439 if (PrintAdaptiveSizePolicy && Verbose) {
440 gclog_or_tty->print(
441 "cmsAdaptiveSizePolicy::checkpoint_roots_initial_end: "
442 "initial pause: %f ", _latest_cms_initial_mark_start_to_end_time_secs);
443 }
444 }
446 _STW_timer.reset();
447 _STW_timer.start();
448 }
450 void CMSAdaptiveSizePolicy::checkpoint_roots_final_begin() {
451 _STW_timer.stop();
452 _latest_cms_initial_mark_end_to_remark_start_secs = _STW_timer.seconds();
453 // Start accumumlating time for the remark in the STW timer.
454 _STW_timer.reset();
455 _STW_timer.start();
456 }
458 void CMSAdaptiveSizePolicy::checkpoint_roots_final_end(
459 GCCause::Cause gc_cause) {
460 _STW_timer.stop();
461 if (gc_cause != GCCause::_java_lang_system_gc ||
462 UseAdaptiveSizePolicyWithSystemGC) {
463 // Total initial mark pause + remark pause.
464 _latest_cms_remark_start_to_end_time_secs = _STW_timer.seconds();
465 double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs +
466 _latest_cms_remark_start_to_end_time_secs;
467 double STW_time_in_ms = STW_time_in_seconds * MILLIUNITS;
469 avg_remark_pause()->sample(_latest_cms_remark_start_to_end_time_secs);
471 // Sample total for initial mark + remark
472 avg_cms_STW_time()->sample(STW_time_in_seconds);
474 if (PrintAdaptiveSizePolicy && Verbose) {
475 gclog_or_tty->print("cmsAdaptiveSizePolicy::checkpoint_roots_final_end: "
476 "remark pause: %f", _latest_cms_remark_start_to_end_time_secs);
477 }
479 }
480 // Don't start the STW times here because the concurrent
481 // sweep and reset has not happened.
482 // Keep the old comment above in case I don't understand
483 // what is going on but now
484 // Start the STW timer because it is used by ms_collection_begin()
485 // and ms_collection_end() to get the sweep time if a MS is being
486 // done in the foreground.
487 _STW_timer.reset();
488 _STW_timer.start();
489 }
491 void CMSAdaptiveSizePolicy::msc_collection_begin() {
492 if (PrintAdaptiveSizePolicy && Verbose) {
493 gclog_or_tty->print(" ");
494 gclog_or_tty->stamp();
495 gclog_or_tty->print(": msc_collection_begin ");
496 }
497 _STW_timer.stop();
498 _latest_cms_msc_end_to_msc_start_time_secs = _STW_timer.seconds();
499 if (PrintAdaptiveSizePolicy && Verbose) {
500 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::msc_collection_begin: "
501 "mutator time %f",
502 _latest_cms_msc_end_to_msc_start_time_secs);
503 }
504 avg_msc_interval()->sample(_latest_cms_msc_end_to_msc_start_time_secs);
505 _STW_timer.reset();
506 _STW_timer.start();
507 }
509 void CMSAdaptiveSizePolicy::msc_collection_end(GCCause::Cause gc_cause) {
510 if (PrintAdaptiveSizePolicy && Verbose) {
511 gclog_or_tty->print(" ");
512 gclog_or_tty->stamp();
513 gclog_or_tty->print(": msc_collection_end ");
514 }
515 _STW_timer.stop();
516 if (gc_cause != GCCause::_java_lang_system_gc ||
517 UseAdaptiveSizePolicyWithSystemGC) {
518 double msc_pause_in_seconds = _STW_timer.seconds();
519 if ((_latest_cms_msc_end_to_msc_start_time_secs > 0.0) &&
520 (msc_pause_in_seconds > 0.0)) {
521 avg_msc_pause()->sample(msc_pause_in_seconds);
522 double mutator_time_in_seconds = 0.0;
523 if (_latest_cms_collection_end_to_collection_start_secs == 0.0) {
524 // This assertion may fail because of time stamp gradularity.
525 // Comment it out and investiage it at a later time. The large
526 // time stamp granularity occurs on some older linux systems.
527 #ifndef CLOCK_GRANULARITY_TOO_LARGE
528 assert((_latest_cms_concurrent_marking_time_secs == 0.0) &&
529 (_latest_cms_concurrent_precleaning_time_secs == 0.0) &&
530 (_latest_cms_concurrent_sweeping_time_secs == 0.0),
531 "There should not be any concurrent time");
532 #endif
533 // A concurrent collection did not start. Mutator time
534 // between collections comes from the STW MSC timer.
535 mutator_time_in_seconds = _latest_cms_msc_end_to_msc_start_time_secs;
536 } else {
537 // The concurrent collection did start so count the mutator
538 // time to the start of the concurrent collection. In this
539 // case the _latest_cms_msc_end_to_msc_start_time_secs measures
540 // the time between the initial mark or remark and the
541 // start of the MSC. That has no real meaning.
542 mutator_time_in_seconds = _latest_cms_collection_end_to_collection_start_secs;
543 }
545 double latest_cms_sum_concurrent_phases_time_secs =
546 concurrent_collection_time();
547 double interval_in_seconds =
548 mutator_time_in_seconds +
549 _latest_cms_initial_mark_start_to_end_time_secs +
550 _latest_cms_remark_start_to_end_time_secs +
551 latest_cms_sum_concurrent_phases_time_secs +
552 msc_pause_in_seconds;
554 if (PrintAdaptiveSizePolicy && Verbose) {
555 gclog_or_tty->print_cr(" interval_in_seconds %f \n"
556 " mutator_time_in_seconds %f \n"
557 " _latest_cms_initial_mark_start_to_end_time_secs %f\n"
558 " _latest_cms_remark_start_to_end_time_secs %f\n"
559 " latest_cms_sum_concurrent_phases_time_secs %f\n"
560 " msc_pause_in_seconds %f\n",
561 interval_in_seconds,
562 mutator_time_in_seconds,
563 _latest_cms_initial_mark_start_to_end_time_secs,
564 _latest_cms_remark_start_to_end_time_secs,
565 latest_cms_sum_concurrent_phases_time_secs,
566 msc_pause_in_seconds);
567 }
569 // The concurrent cost is wasted cost but it should be
570 // included.
571 double concurrent_cost = concurrent_collection_cost(interval_in_seconds);
573 // Initial mark and remark, also wasted.
574 double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs +
575 _latest_cms_remark_start_to_end_time_secs;
576 double STW_collection_cost =
577 collection_cost(STW_time_in_seconds, interval_in_seconds) +
578 concurrent_cost;
580 if (PrintAdaptiveSizePolicy && Verbose) {
581 gclog_or_tty->print_cr(" msc_collection_end:\n"
582 "_latest_cms_collection_end_to_collection_start_secs %f\n"
583 "_latest_cms_msc_end_to_msc_start_time_secs %f\n"
584 "_latest_cms_initial_mark_start_to_end_time_secs %f\n"
585 "_latest_cms_remark_start_to_end_time_secs %f\n"
586 "latest_cms_sum_concurrent_phases_time_secs %f\n",
587 _latest_cms_collection_end_to_collection_start_secs,
588 _latest_cms_msc_end_to_msc_start_time_secs,
589 _latest_cms_initial_mark_start_to_end_time_secs,
590 _latest_cms_remark_start_to_end_time_secs,
591 latest_cms_sum_concurrent_phases_time_secs);
593 gclog_or_tty->print_cr(" msc_collection_end: \n"
594 "latest_cms_sum_concurrent_phases_time_secs %f\n"
595 "STW_time_in_seconds %f\n"
596 "msc_pause_in_seconds %f\n",
597 latest_cms_sum_concurrent_phases_time_secs,
598 STW_time_in_seconds,
599 msc_pause_in_seconds);
600 }
602 double cost = concurrent_cost + STW_collection_cost +
603 collection_cost(msc_pause_in_seconds, interval_in_seconds);
605 _avg_msc_gc_cost->sample(cost);
607 // Average this ms cost into all the other types gc costs
608 avg_major_gc_cost()->sample(cost);
610 // Sample for performance counter
611 _avg_msc_interval->sample(interval_in_seconds);
612 if (PrintAdaptiveSizePolicy && Verbose) {
613 gclog_or_tty->print("cmsAdaptiveSizePolicy::msc_collection_end: "
614 "MSC gc cost: %f average: %f", cost,
615 _avg_msc_gc_cost->average());
617 double msc_pause_in_ms = msc_pause_in_seconds * MILLIUNITS;
618 gclog_or_tty->print_cr(" MSC pause: %f (ms) MSC period %f (ms)",
619 msc_pause_in_ms, (double) interval_in_seconds * MILLIUNITS);
620 }
621 }
622 }
624 clear_internal_time_intervals();
626 // Can this call be put into the epilogue?
627 set_first_after_collection();
629 // The concurrent phases keeps track of it's own mutator interval
630 // with this timer. This allows the stop-the-world phase to
631 // be included in the mutator time so that the stop-the-world time
632 // is not double counted. Reset and start it.
633 _concurrent_timer.stop();
634 _concurrent_timer.reset();
635 _concurrent_timer.start();
637 _STW_timer.reset();
638 _STW_timer.start();
639 }
641 void CMSAdaptiveSizePolicy::ms_collection_begin() {
642 if (PrintAdaptiveSizePolicy && Verbose) {
643 gclog_or_tty->print(" ");
644 gclog_or_tty->stamp();
645 gclog_or_tty->print(": ms_collection_begin ");
646 }
647 _STW_timer.stop();
648 _latest_cms_ms_end_to_ms_start = _STW_timer.seconds();
649 if (PrintAdaptiveSizePolicy && Verbose) {
650 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::ms_collection_begin: "
651 "mutator time %f",
652 _latest_cms_ms_end_to_ms_start);
653 }
654 avg_ms_interval()->sample(_STW_timer.seconds());
655 _STW_timer.reset();
656 _STW_timer.start();
657 }
659 void CMSAdaptiveSizePolicy::ms_collection_end(GCCause::Cause gc_cause) {
660 if (PrintAdaptiveSizePolicy && Verbose) {
661 gclog_or_tty->print(" ");
662 gclog_or_tty->stamp();
663 gclog_or_tty->print(": ms_collection_end ");
664 }
665 _STW_timer.stop();
666 if (gc_cause != GCCause::_java_lang_system_gc ||
667 UseAdaptiveSizePolicyWithSystemGC) {
668 // The MS collection is a foreground collection that does all
669 // the parts of a mostly concurrent collection.
670 //
671 // For this collection include the cost of the
672 // initial mark
673 // remark
674 // all concurrent time (scaled down by the
675 // concurrent_processor_fraction). Some
676 // may be zero if the baton was passed before
677 // it was reached.
678 // concurrent marking
679 // sweeping
680 // resetting
681 // STW after baton was passed (STW_in_foreground_in_seconds)
682 double STW_in_foreground_in_seconds = _STW_timer.seconds();
684 double latest_cms_sum_concurrent_phases_time_secs =
685 concurrent_collection_time();
686 if (PrintAdaptiveSizePolicy && Verbose) {
687 gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::ms_collecton_end "
688 "STW_in_foreground_in_seconds %f "
689 "_latest_cms_initial_mark_start_to_end_time_secs %f "
690 "_latest_cms_remark_start_to_end_time_secs %f "
691 "latest_cms_sum_concurrent_phases_time_secs %f "
692 "_latest_cms_ms_marking_start_to_end_time_secs %f "
693 "_latest_cms_ms_end_to_ms_start %f",
694 STW_in_foreground_in_seconds,
695 _latest_cms_initial_mark_start_to_end_time_secs,
696 _latest_cms_remark_start_to_end_time_secs,
697 latest_cms_sum_concurrent_phases_time_secs,
698 _latest_cms_ms_marking_start_to_end_time_secs,
699 _latest_cms_ms_end_to_ms_start);
700 }
702 double STW_marking_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs +
703 _latest_cms_remark_start_to_end_time_secs;
704 #ifndef CLOCK_GRANULARITY_TOO_LARGE
705 assert(_latest_cms_ms_marking_start_to_end_time_secs == 0.0 ||
706 latest_cms_sum_concurrent_phases_time_secs == 0.0,
707 "marking done twice?");
708 #endif
709 double ms_time_in_seconds = STW_marking_in_seconds +
710 STW_in_foreground_in_seconds +
711 _latest_cms_ms_marking_start_to_end_time_secs +
712 scaled_concurrent_collection_time();
713 avg_ms_pause()->sample(ms_time_in_seconds);
714 // Use the STW costs from the initial mark and remark plus
715 // the cost of the concurrent phase to calculate a
716 // collection cost.
717 double cost = 0.0;
718 if ((_latest_cms_ms_end_to_ms_start > 0.0) &&
719 (ms_time_in_seconds > 0.0)) {
720 double interval_in_seconds =
721 _latest_cms_ms_end_to_ms_start + ms_time_in_seconds;
723 if (PrintAdaptiveSizePolicy && Verbose) {
724 gclog_or_tty->print_cr("\n ms_time_in_seconds %f "
725 "latest_cms_sum_concurrent_phases_time_secs %f "
726 "interval_in_seconds %f",
727 ms_time_in_seconds,
728 latest_cms_sum_concurrent_phases_time_secs,
729 interval_in_seconds);
730 }
732 cost = collection_cost(ms_time_in_seconds, interval_in_seconds);
734 _avg_ms_gc_cost->sample(cost);
735 // Average this ms cost into all the other types gc costs
736 avg_major_gc_cost()->sample(cost);
738 // Sample for performance counter
739 _avg_ms_interval->sample(interval_in_seconds);
740 }
741 if (PrintAdaptiveSizePolicy && Verbose) {
742 gclog_or_tty->print("cmsAdaptiveSizePolicy::ms_collection_end: "
743 "MS gc cost: %f average: %f", cost, _avg_ms_gc_cost->average());
745 double ms_time_in_ms = ms_time_in_seconds * MILLIUNITS;
746 gclog_or_tty->print_cr(" MS pause: %f (ms) MS period %f (ms)",
747 ms_time_in_ms,
748 _latest_cms_ms_end_to_ms_start * MILLIUNITS);
749 }
750 }
752 // Consider putting this code (here to end) into a
753 // method for convenience.
754 clear_internal_time_intervals();
756 set_first_after_collection();
758 // The concurrent phases keeps track of it's own mutator interval
759 // with this timer. This allows the stop-the-world phase to
760 // be included in the mutator time so that the stop-the-world time
761 // is not double counted. Reset and start it.
762 _concurrent_timer.stop();
763 _concurrent_timer.reset();
764 _concurrent_timer.start();
766 _STW_timer.reset();
767 _STW_timer.start();
768 }
770 void CMSAdaptiveSizePolicy::clear_internal_time_intervals() {
771 _latest_cms_reset_end_to_initial_mark_start_secs = 0.0;
772 _latest_cms_initial_mark_end_to_remark_start_secs = 0.0;
773 _latest_cms_collection_end_to_collection_start_secs = 0.0;
774 _latest_cms_concurrent_marking_time_secs = 0.0;
775 _latest_cms_concurrent_precleaning_time_secs = 0.0;
776 _latest_cms_concurrent_sweeping_time_secs = 0.0;
777 _latest_cms_msc_end_to_msc_start_time_secs = 0.0;
778 _latest_cms_ms_end_to_ms_start = 0.0;
779 _latest_cms_remark_start_to_end_time_secs = 0.0;
780 _latest_cms_initial_mark_start_to_end_time_secs = 0.0;
781 _latest_cms_ms_marking_start_to_end_time_secs = 0.0;
782 }
784 void CMSAdaptiveSizePolicy::clear_generation_free_space_flags() {
785 AdaptiveSizePolicy::clear_generation_free_space_flags();
787 set_change_young_gen_for_maj_pauses(0);
788 }
790 void CMSAdaptiveSizePolicy::concurrent_phases_resume() {
791 if (PrintAdaptiveSizePolicy && Verbose) {
792 gclog_or_tty->stamp();
793 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_phases_resume()");
794 }
795 _concurrent_timer.start();
796 }
798 double CMSAdaptiveSizePolicy::time_since_major_gc() const {
799 _concurrent_timer.stop();
800 double time_since_cms_gc = _concurrent_timer.seconds();
801 _concurrent_timer.start();
802 _STW_timer.stop();
803 double time_since_STW_gc = _STW_timer.seconds();
804 _STW_timer.start();
806 return MIN2(time_since_cms_gc, time_since_STW_gc);
807 }
809 double CMSAdaptiveSizePolicy::major_gc_interval_average_for_decay() const {
810 double cms_interval = _avg_concurrent_interval->average();
811 double msc_interval = _avg_msc_interval->average();
812 double ms_interval = _avg_ms_interval->average();
814 return MAX3(cms_interval, msc_interval, ms_interval);
815 }
817 double CMSAdaptiveSizePolicy::cms_gc_cost() const {
818 return avg_major_gc_cost()->average();
819 }
821 void CMSAdaptiveSizePolicy::ms_collection_marking_begin() {
822 _STW_timer.stop();
823 // Start accumumlating time for the marking in the STW timer.
824 _STW_timer.reset();
825 _STW_timer.start();
826 }
828 void CMSAdaptiveSizePolicy::ms_collection_marking_end(
829 GCCause::Cause gc_cause) {
830 _STW_timer.stop();
831 if (gc_cause != GCCause::_java_lang_system_gc ||
832 UseAdaptiveSizePolicyWithSystemGC) {
833 _latest_cms_ms_marking_start_to_end_time_secs = _STW_timer.seconds();
834 if (PrintAdaptiveSizePolicy && Verbose) {
835 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::"
836 "msc_collection_marking_end: mutator time %f",
837 _latest_cms_ms_marking_start_to_end_time_secs);
838 }
839 }
840 _STW_timer.reset();
841 _STW_timer.start();
842 }
844 double CMSAdaptiveSizePolicy::gc_cost() const {
845 double cms_gen_cost = cms_gc_cost();
846 double result = MIN2(1.0, minor_gc_cost() + cms_gen_cost);
847 assert(result >= 0.0, "Both minor and major costs are non-negative");
848 return result;
849 }
851 // Cost of collection (unit-less)
852 double CMSAdaptiveSizePolicy::collection_cost(double pause_in_seconds,
853 double interval_in_seconds) {
854 // Cost of collection (unit-less)
855 double cost = 0.0;
856 if ((interval_in_seconds > 0.0) &&
857 (pause_in_seconds > 0.0)) {
858 cost =
859 pause_in_seconds / interval_in_seconds;
860 }
861 return cost;
862 }
864 size_t CMSAdaptiveSizePolicy::adjust_eden_for_pause_time(size_t cur_eden) {
865 size_t change = 0;
866 size_t desired_eden = cur_eden;
868 // reduce eden size
869 change = eden_decrement_aligned_down(cur_eden);
870 desired_eden = cur_eden - change;
872 if (PrintAdaptiveSizePolicy && Verbose) {
873 gclog_or_tty->print_cr(
874 "CMSAdaptiveSizePolicy::adjust_eden_for_pause_time "
875 "adjusting eden for pause time. "
876 " starting eden size " SIZE_FORMAT
877 " reduced eden size " SIZE_FORMAT
878 " eden delta " SIZE_FORMAT,
879 cur_eden, desired_eden, change);
880 }
882 return desired_eden;
883 }
885 size_t CMSAdaptiveSizePolicy::adjust_eden_for_throughput(size_t cur_eden) {
887 size_t desired_eden = cur_eden;
889 set_change_young_gen_for_throughput(increase_young_gen_for_througput_true);
891 size_t change = eden_increment_aligned_up(cur_eden);
892 size_t scaled_change = scale_by_gen_gc_cost(change, minor_gc_cost());
894 if (cur_eden + scaled_change > cur_eden) {
895 desired_eden = cur_eden + scaled_change;
896 }
898 _young_gen_change_for_minor_throughput++;
900 if (PrintAdaptiveSizePolicy && Verbose) {
901 gclog_or_tty->print_cr(
902 "CMSAdaptiveSizePolicy::adjust_eden_for_throughput "
903 "adjusting eden for throughput. "
904 " starting eden size " SIZE_FORMAT
905 " increased eden size " SIZE_FORMAT
906 " eden delta " SIZE_FORMAT,
907 cur_eden, desired_eden, scaled_change);
908 }
910 return desired_eden;
911 }
913 size_t CMSAdaptiveSizePolicy::adjust_eden_for_footprint(size_t cur_eden) {
915 set_decrease_for_footprint(decrease_young_gen_for_footprint_true);
917 size_t change = eden_decrement(cur_eden);
918 size_t desired_eden_size = cur_eden - change;
920 if (PrintAdaptiveSizePolicy && Verbose) {
921 gclog_or_tty->print_cr(
922 "CMSAdaptiveSizePolicy::adjust_eden_for_footprint "
923 "adjusting eden for footprint. "
924 " starting eden size " SIZE_FORMAT
925 " reduced eden size " SIZE_FORMAT
926 " eden delta " SIZE_FORMAT,
927 cur_eden, desired_eden_size, change);
928 }
929 return desired_eden_size;
930 }
932 // The eden and promo versions should be combined if possible.
933 // They are the same except that the sizes of the decrement
934 // and increment are different for eden and promo.
935 size_t CMSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) {
936 size_t delta = eden_decrement(cur_eden);
937 return align_size_down(delta, generation_alignment());
938 }
940 size_t CMSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) {
941 size_t delta = eden_increment(cur_eden);
942 return align_size_up(delta, generation_alignment());
943 }
945 size_t CMSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) {
946 size_t delta = promo_decrement(cur_promo);
947 return align_size_down(delta, generation_alignment());
948 }
950 size_t CMSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) {
951 size_t delta = promo_increment(cur_promo);
952 return align_size_up(delta, generation_alignment());
953 }
956 void CMSAdaptiveSizePolicy::compute_young_generation_free_space(size_t cur_eden,
957 size_t max_eden_size)
958 {
959 size_t desired_eden_size = cur_eden;
960 size_t eden_limit = max_eden_size;
962 // Printout input
963 if (PrintGC && PrintAdaptiveSizePolicy) {
964 gclog_or_tty->print_cr(
965 "CMSAdaptiveSizePolicy::compute_young_generation_free_space: "
966 "cur_eden " SIZE_FORMAT,
967 cur_eden);
968 }
970 // Used for diagnostics
971 clear_generation_free_space_flags();
973 if (_avg_minor_pause->padded_average() > gc_pause_goal_sec()) {
974 if (minor_pause_young_estimator()->decrement_will_decrease()) {
975 // If the minor pause is too long, shrink the young gen.
976 set_change_young_gen_for_min_pauses(
977 decrease_young_gen_for_min_pauses_true);
978 desired_eden_size = adjust_eden_for_pause_time(desired_eden_size);
979 }
980 } else if ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) ||
981 (avg_initial_pause()->padded_average() > gc_pause_goal_sec())) {
982 // The remark or initial pauses are not meeting the goal. Should
983 // the generation be shrunk?
984 if (get_and_clear_first_after_collection() &&
985 ((avg_remark_pause()->padded_average() > gc_pause_goal_sec() &&
986 remark_pause_young_estimator()->decrement_will_decrease()) ||
987 (avg_initial_pause()->padded_average() > gc_pause_goal_sec() &&
988 initial_pause_young_estimator()->decrement_will_decrease()))) {
990 set_change_young_gen_for_maj_pauses(
991 decrease_young_gen_for_maj_pauses_true);
993 // If the remark or initial pause is too long and this is the
994 // first young gen collection after a cms collection, shrink
995 // the young gen.
996 desired_eden_size = adjust_eden_for_pause_time(desired_eden_size);
997 }
998 // If not the first young gen collection after a cms collection,
999 // don't do anything. In this case an adjustment has already
1000 // been made and the results of the adjustment has not yet been
1001 // measured.
1002 } else if ((minor_gc_cost() >= 0.0) &&
1003 (adjusted_mutator_cost() < _throughput_goal)) {
1004 desired_eden_size = adjust_eden_for_throughput(desired_eden_size);
1005 } else {
1006 desired_eden_size = adjust_eden_for_footprint(desired_eden_size);
1007 }
1009 if (PrintGC && PrintAdaptiveSizePolicy) {
1010 gclog_or_tty->print_cr(
1011 "CMSAdaptiveSizePolicy::compute_young_generation_free_space limits:"
1012 " desired_eden_size: " SIZE_FORMAT
1013 " old_eden_size: " SIZE_FORMAT,
1014 desired_eden_size, cur_eden);
1015 }
1017 set_eden_size(desired_eden_size);
1018 }
1020 size_t CMSAdaptiveSizePolicy::adjust_promo_for_pause_time(size_t cur_promo) {
1021 size_t change = 0;
1022 size_t desired_promo = cur_promo;
1023 // Move this test up to caller like the adjust_eden_for_pause_time()
1024 // call.
1025 if ((AdaptiveSizePausePolicy == 0) &&
1026 ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) ||
1027 (avg_initial_pause()->padded_average() > gc_pause_goal_sec()))) {
1028 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true);
1029 change = promo_decrement_aligned_down(cur_promo);
1030 desired_promo = cur_promo - change;
1031 } else if ((AdaptiveSizePausePolicy > 0) &&
1032 (((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) &&
1033 remark_pause_old_estimator()->decrement_will_decrease()) ||
1034 ((avg_initial_pause()->padded_average() > gc_pause_goal_sec()) &&
1035 initial_pause_old_estimator()->decrement_will_decrease()))) {
1036 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true);
1037 change = promo_decrement_aligned_down(cur_promo);
1038 desired_promo = cur_promo - change;
1039 }
1041 if ((change != 0) &&PrintAdaptiveSizePolicy && Verbose) {
1042 gclog_or_tty->print_cr(
1043 "CMSAdaptiveSizePolicy::adjust_promo_for_pause_time "
1044 "adjusting promo for pause time. "
1045 " starting promo size " SIZE_FORMAT
1046 " reduced promo size " SIZE_FORMAT
1047 " promo delta " SIZE_FORMAT,
1048 cur_promo, desired_promo, change);
1049 }
1051 return desired_promo;
1052 }
1054 // Try to share this with PS.
1055 size_t CMSAdaptiveSizePolicy::scale_by_gen_gc_cost(size_t base_change,
1056 double gen_gc_cost) {
1058 // Calculate the change to use for the tenured gen.
1059 size_t scaled_change = 0;
1060 // Can the increment to the generation be scaled?
1061 if (gc_cost() >= 0.0 && gen_gc_cost >= 0.0) {
1062 double scale_by_ratio = gen_gc_cost / gc_cost();
1063 scaled_change =
1064 (size_t) (scale_by_ratio * (double) base_change);
1065 if (PrintAdaptiveSizePolicy && Verbose) {
1066 gclog_or_tty->print_cr(
1067 "Scaled tenured increment: " SIZE_FORMAT " by %f down to "
1068 SIZE_FORMAT,
1069 base_change, scale_by_ratio, scaled_change);
1070 }
1071 } else if (gen_gc_cost >= 0.0) {
1072 // Scaling is not going to work. If the major gc time is the
1073 // larger than the other GC costs, give it a full increment.
1074 if (gen_gc_cost >= (gc_cost() - gen_gc_cost)) {
1075 scaled_change = base_change;
1076 }
1077 } else {
1078 // Don't expect to get here but it's ok if it does
1079 // in the product build since the delta will be 0
1080 // and nothing will change.
1081 assert(false, "Unexpected value for gc costs");
1082 }
1084 return scaled_change;
1085 }
1087 size_t CMSAdaptiveSizePolicy::adjust_promo_for_throughput(size_t cur_promo) {
1089 size_t desired_promo = cur_promo;
1091 set_change_old_gen_for_throughput(increase_old_gen_for_throughput_true);
1093 size_t change = promo_increment_aligned_up(cur_promo);
1094 size_t scaled_change = scale_by_gen_gc_cost(change, major_gc_cost());
1096 if (cur_promo + scaled_change > cur_promo) {
1097 desired_promo = cur_promo + scaled_change;
1098 }
1100 _old_gen_change_for_major_throughput++;
1102 if (PrintAdaptiveSizePolicy && Verbose) {
1103 gclog_or_tty->print_cr(
1104 "CMSAdaptiveSizePolicy::adjust_promo_for_throughput "
1105 "adjusting promo for throughput. "
1106 " starting promo size " SIZE_FORMAT
1107 " increased promo size " SIZE_FORMAT
1108 " promo delta " SIZE_FORMAT,
1109 cur_promo, desired_promo, scaled_change);
1110 }
1112 return desired_promo;
1113 }
1115 size_t CMSAdaptiveSizePolicy::adjust_promo_for_footprint(size_t cur_promo,
1116 size_t cur_eden) {
1118 set_decrease_for_footprint(decrease_young_gen_for_footprint_true);
1120 size_t change = promo_decrement(cur_promo);
1121 size_t desired_promo_size = cur_promo - change;
1123 if (PrintAdaptiveSizePolicy && Verbose) {
1124 gclog_or_tty->print_cr(
1125 "CMSAdaptiveSizePolicy::adjust_promo_for_footprint "
1126 "adjusting promo for footprint. "
1127 " starting promo size " SIZE_FORMAT
1128 " reduced promo size " SIZE_FORMAT
1129 " promo delta " SIZE_FORMAT,
1130 cur_promo, desired_promo_size, change);
1131 }
1132 return desired_promo_size;
1133 }
1135 void CMSAdaptiveSizePolicy::compute_tenured_generation_free_space(
1136 size_t cur_tenured_free,
1137 size_t max_tenured_available,
1138 size_t cur_eden) {
1139 // This can be bad if the desired value grows/shrinks without
1140 // any connection to the read free space
1141 size_t desired_promo_size = promo_size();
1142 size_t tenured_limit = max_tenured_available;
1144 // Printout input
1145 if (PrintGC && PrintAdaptiveSizePolicy) {
1146 gclog_or_tty->print_cr(
1147 "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space: "
1148 "cur_tenured_free " SIZE_FORMAT
1149 " max_tenured_available " SIZE_FORMAT,
1150 cur_tenured_free, max_tenured_available);
1151 }
1153 // Used for diagnostics
1154 clear_generation_free_space_flags();
1156 set_decide_at_full_gc(decide_at_full_gc_true);
1157 if (avg_remark_pause()->padded_average() > gc_pause_goal_sec() ||
1158 avg_initial_pause()->padded_average() > gc_pause_goal_sec()) {
1159 desired_promo_size = adjust_promo_for_pause_time(cur_tenured_free);
1160 } else if (avg_minor_pause()->padded_average() > gc_pause_goal_sec()) {
1161 // Nothing to do since the minor collections are too large and
1162 // this method only deals with the cms generation.
1163 } else if ((cms_gc_cost() >= 0.0) &&
1164 (adjusted_mutator_cost() < _throughput_goal)) {
1165 desired_promo_size = adjust_promo_for_throughput(cur_tenured_free);
1166 } else {
1167 desired_promo_size = adjust_promo_for_footprint(cur_tenured_free,
1168 cur_eden);
1169 }
1171 if (PrintGC && PrintAdaptiveSizePolicy) {
1172 gclog_or_tty->print_cr(
1173 "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space limits:"
1174 " desired_promo_size: " SIZE_FORMAT
1175 " old_promo_size: " SIZE_FORMAT,
1176 desired_promo_size, cur_tenured_free);
1177 }
1179 set_promo_size(desired_promo_size);
1180 }
1182 int CMSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold(
1183 bool is_survivor_overflow,
1184 int tenuring_threshold,
1185 size_t survivor_limit) {
1186 assert(survivor_limit >= generation_alignment(),
1187 "survivor_limit too small");
1188 assert((size_t)align_size_down(survivor_limit, generation_alignment())
1189 == survivor_limit, "survivor_limit not aligned");
1191 // Change UsePSAdaptiveSurvivorSizePolicy -> UseAdaptiveSurvivorSizePolicy?
1192 if (!UsePSAdaptiveSurvivorSizePolicy ||
1193 !young_gen_policy_is_ready()) {
1194 return tenuring_threshold;
1195 }
1197 // We'll decide whether to increase or decrease the tenuring
1198 // threshold based partly on the newly computed survivor size
1199 // (if we hit the maximum limit allowed, we'll always choose to
1200 // decrement the threshold).
1201 bool incr_tenuring_threshold = false;
1202 bool decr_tenuring_threshold = false;
1204 set_decrement_tenuring_threshold_for_gc_cost(false);
1205 set_increment_tenuring_threshold_for_gc_cost(false);
1206 set_decrement_tenuring_threshold_for_survivor_limit(false);
1208 if (!is_survivor_overflow) {
1209 // Keep running averages on how much survived
1211 // We use the tenuring threshold to equalize the cost of major
1212 // and minor collections.
1213 // ThresholdTolerance is used to indicate how sensitive the
1214 // tenuring threshold is to differences in cost betweent the
1215 // collection types.
1217 // Get the times of interest. This involves a little work, so
1218 // we cache the values here.
1219 const double major_cost = major_gc_cost();
1220 const double minor_cost = minor_gc_cost();
1222 if (minor_cost > major_cost * _threshold_tolerance_percent) {
1223 // Minor times are getting too long; lower the threshold so
1224 // less survives and more is promoted.
1225 decr_tenuring_threshold = true;
1226 set_decrement_tenuring_threshold_for_gc_cost(true);
1227 } else if (major_cost > minor_cost * _threshold_tolerance_percent) {
1228 // Major times are too long, so we want less promotion.
1229 incr_tenuring_threshold = true;
1230 set_increment_tenuring_threshold_for_gc_cost(true);
1231 }
1233 } else {
1234 // Survivor space overflow occurred, so promoted and survived are
1235 // not accurate. We'll make our best guess by combining survived
1236 // and promoted and count them as survivors.
1237 //
1238 // We'll lower the tenuring threshold to see if we can correct
1239 // things. Also, set the survivor size conservatively. We're
1240 // trying to avoid many overflows from occurring if defnew size
1241 // is just too small.
1243 decr_tenuring_threshold = true;
1244 }
1246 // The padded average also maintains a deviation from the average;
1247 // we use this to see how good of an estimate we have of what survived.
1248 // We're trying to pad the survivor size as little as possible without
1249 // overflowing the survivor spaces.
1250 size_t target_size = align_size_up((size_t)_avg_survived->padded_average(),
1251 generation_alignment());
1252 target_size = MAX2(target_size, generation_alignment());
1254 if (target_size > survivor_limit) {
1255 // Target size is bigger than we can handle. Let's also reduce
1256 // the tenuring threshold.
1257 target_size = survivor_limit;
1258 decr_tenuring_threshold = true;
1259 set_decrement_tenuring_threshold_for_survivor_limit(true);
1260 }
1262 // Finally, increment or decrement the tenuring threshold, as decided above.
1263 // We test for decrementing first, as we might have hit the target size
1264 // limit.
1265 if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1266 if (tenuring_threshold > 1) {
1267 tenuring_threshold--;
1268 }
1269 } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1270 if (tenuring_threshold < MaxTenuringThreshold) {
1271 tenuring_threshold++;
1272 }
1273 }
1275 // We keep a running average of the amount promoted which is used
1276 // to decide when we should collect the old generation (when
1277 // the amount of old gen free space is less than what we expect to
1278 // promote).
1280 if (PrintAdaptiveSizePolicy) {
1281 // A little more detail if Verbose is on
1282 GenCollectedHeap* gch = GenCollectedHeap::heap();
1283 if (Verbose) {
1284 gclog_or_tty->print( " avg_survived: %f"
1285 " avg_deviation: %f",
1286 _avg_survived->average(),
1287 _avg_survived->deviation());
1288 }
1290 gclog_or_tty->print( " avg_survived_padded_avg: %f",
1291 _avg_survived->padded_average());
1293 if (Verbose) {
1294 gclog_or_tty->print( " avg_promoted_avg: %f"
1295 " avg_promoted_dev: %f",
1296 gch->gc_stats(1)->avg_promoted()->average(),
1297 gch->gc_stats(1)->avg_promoted()->deviation());
1298 }
1300 gclog_or_tty->print( " avg_promoted_padded_avg: %f"
1301 " avg_pretenured_padded_avg: %f"
1302 " tenuring_thresh: %d"
1303 " target_size: " SIZE_FORMAT
1304 " survivor_limit: " SIZE_FORMAT,
1305 gch->gc_stats(1)->avg_promoted()->padded_average(),
1306 _avg_pretenured->padded_average(),
1307 tenuring_threshold, target_size, survivor_limit);
1308 gclog_or_tty->cr();
1309 }
1311 set_survivor_size(target_size);
1313 return tenuring_threshold;
1314 }
1316 bool CMSAdaptiveSizePolicy::get_and_clear_first_after_collection() {
1317 bool result = _first_after_collection;
1318 _first_after_collection = false;
1319 return result;
1320 }
1322 bool CMSAdaptiveSizePolicy::print_adaptive_size_policy_on(
1323 outputStream* st) const {
1325 if (!UseAdaptiveSizePolicy) return false;
1327 GenCollectedHeap* gch = GenCollectedHeap::heap();
1328 Generation* gen0 = gch->get_gen(0);
1329 DefNewGeneration* def_new = gen0->as_DefNewGeneration();
1330 return
1331 AdaptiveSizePolicy::print_adaptive_size_policy_on(
1332 st,
1333 def_new->tenuring_threshold());
1334 }
