1 /*
2 * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp"
27 #include "gc_implementation/shared/gcStats.hpp"
28 #include "memory/defNewGeneration.hpp"
29 #include "memory/genCollectedHeap.hpp"
30 #include "runtime/thread.hpp"
31 #ifdef TARGET_OS_FAMILY_linux
32 # include "os_linux.inline.hpp"
33 #endif
34 #ifdef TARGET_OS_FAMILY_solaris
35 # include "os_solaris.inline.hpp"
36 #endif
37 #ifdef TARGET_OS_FAMILY_windows
38 # include "os_windows.inline.hpp"
39 #endif
40 elapsedTimer CMSAdaptiveSizePolicy::_concurrent_timer;
41 elapsedTimer CMSAdaptiveSizePolicy::_STW_timer;
42
43 // Defined if the granularity of the time measurements is potentially too large.
44 #define CLOCK_GRANULARITY_TOO_LARGE
45
46 CMSAdaptiveSizePolicy::CMSAdaptiveSizePolicy(size_t init_eden_size,
47 size_t init_promo_size,
48 size_t init_survivor_size,
49 double max_gc_minor_pause_sec,
50 double max_gc_pause_sec,
51 uint gc_cost_ratio) :
52 AdaptiveSizePolicy(init_eden_size,
53 init_promo_size,
54 init_survivor_size,
55 max_gc_pause_sec,
56 gc_cost_ratio) {
57
58 clear_internal_time_intervals();
59
60 _processor_count = os::active_processor_count();
61
62 if (CMSConcurrentMTEnabled && (ConcGCThreads > 1)) {
63 assert(_processor_count > 0, "Processor count is suspect");
64 _concurrent_processor_count = MIN2((uint) ConcGCThreads,
65 (uint) _processor_count);
66 } else {
67 _concurrent_processor_count = 1;
68 }
69
70 _avg_concurrent_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
71 _avg_concurrent_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
72 _avg_concurrent_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
73
74 _avg_initial_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight,
75 PausePadding);
76 _avg_remark_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight,
77 PausePadding);
78
79 _avg_cms_STW_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
80 _avg_cms_STW_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
81
82 _avg_cms_free = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
83 _avg_cms_free_at_sweep = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
84 _avg_cms_promo = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
85
86 // Mark-sweep-compact
87 _avg_msc_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
88 _avg_msc_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
89 _avg_msc_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
90
91 // Mark-sweep
92 _avg_ms_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
93 _avg_ms_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
94 _avg_ms_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
95
96 // Variables that estimate pause times as a function of generation
97 // size.
98 _remark_pause_old_estimator =
99 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
100 _initial_pause_old_estimator =
101 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
102 _remark_pause_young_estimator =
103 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
104 _initial_pause_young_estimator =
105 new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
106
107 // Alignment comes from that used in ReservedSpace.
108 _generation_alignment = os::vm_allocation_granularity();
109
110 // Start the concurrent timer here so that the first
111 // concurrent_phases_begin() measures a finite mutator
112 // time. A finite mutator time is used to determine
113 // if a concurrent collection has been started. If this
114 // proves to be a problem, use some explicit flag to
115 // signal that a concurrent collection has been started.
116 _concurrent_timer.start();
117 _STW_timer.start();
118 }
119
120 double CMSAdaptiveSizePolicy::concurrent_processor_fraction() {
121 // For now assume no other daemon threads are taking alway
122 // cpu's from the application.
123 return ((double) _concurrent_processor_count / (double) _processor_count);
124 }
125
126 double CMSAdaptiveSizePolicy::concurrent_collection_cost(
127 double interval_in_seconds) {
128 // When the precleaning and sweeping phases use multiple
129 // threads, change one_processor_fraction to
130 // concurrent_processor_fraction().
131 double one_processor_fraction = 1.0 / ((double) processor_count());
132 double concurrent_cost =
133 collection_cost(_latest_cms_concurrent_marking_time_secs,
134 interval_in_seconds) * concurrent_processor_fraction() +
135 collection_cost(_latest_cms_concurrent_precleaning_time_secs,
136 interval_in_seconds) * one_processor_fraction +
137 collection_cost(_latest_cms_concurrent_sweeping_time_secs,
138 interval_in_seconds) * one_processor_fraction;
139 if (PrintAdaptiveSizePolicy && Verbose) {
140 gclog_or_tty->print_cr(
141 "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_cost(%f) "
142 "_latest_cms_concurrent_marking_cost %f "
143 "_latest_cms_concurrent_precleaning_cost %f "
144 "_latest_cms_concurrent_sweeping_cost %f "
145 "concurrent_processor_fraction %f "
146 "concurrent_cost %f ",
147 interval_in_seconds,
148 collection_cost(_latest_cms_concurrent_marking_time_secs,
149 interval_in_seconds),
150 collection_cost(_latest_cms_concurrent_precleaning_time_secs,
151 interval_in_seconds),
152 collection_cost(_latest_cms_concurrent_sweeping_time_secs,
153 interval_in_seconds),
154 concurrent_processor_fraction(),
155 concurrent_cost);
156 }
157 return concurrent_cost;
158 }
159
160 double CMSAdaptiveSizePolicy::concurrent_collection_time() {
161 double latest_cms_sum_concurrent_phases_time_secs =
162 _latest_cms_concurrent_marking_time_secs +
163 _latest_cms_concurrent_precleaning_time_secs +
164 _latest_cms_concurrent_sweeping_time_secs;
165 return latest_cms_sum_concurrent_phases_time_secs;
166 }
167
168 double CMSAdaptiveSizePolicy::scaled_concurrent_collection_time() {
169 // When the precleaning and sweeping phases use multiple
170 // threads, change one_processor_fraction to
171 // concurrent_processor_fraction().
172 double one_processor_fraction = 1.0 / ((double) processor_count());
173 double latest_cms_sum_concurrent_phases_time_secs =
174 _latest_cms_concurrent_marking_time_secs * concurrent_processor_fraction() +
175 _latest_cms_concurrent_precleaning_time_secs * one_processor_fraction +
176 _latest_cms_concurrent_sweeping_time_secs * one_processor_fraction ;
177 if (PrintAdaptiveSizePolicy && Verbose) {
178 gclog_or_tty->print_cr(
179 "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_time "
180 "_latest_cms_concurrent_marking_time_secs %f "
181 "_latest_cms_concurrent_precleaning_time_secs %f "
182 "_latest_cms_concurrent_sweeping_time_secs %f "
183 "concurrent_processor_fraction %f "
184 "latest_cms_sum_concurrent_phases_time_secs %f ",
185 _latest_cms_concurrent_marking_time_secs,
186 _latest_cms_concurrent_precleaning_time_secs,
187 _latest_cms_concurrent_sweeping_time_secs,
188 concurrent_processor_fraction(),
189 latest_cms_sum_concurrent_phases_time_secs);
190 }
191 return latest_cms_sum_concurrent_phases_time_secs;
192 }
193
194 void CMSAdaptiveSizePolicy::update_minor_pause_old_estimator(
195 double minor_pause_in_ms) {
196 // Get the equivalent of the free space
197 // that is available for promotions in the CMS generation
198 // and use that to update _minor_pause_old_estimator
199
200 // Don't implement this until it is needed. A warning is
201 // printed if _minor_pause_old_estimator is used.
202 }
203
204 void CMSAdaptiveSizePolicy::concurrent_marking_begin() {
205 if (PrintAdaptiveSizePolicy && Verbose) {
206 gclog_or_tty->print(" ");
207 gclog_or_tty->stamp();
208 gclog_or_tty->print(": concurrent_marking_begin ");
209 }
210 // Update the interval time
211 _concurrent_timer.stop();
212 _latest_cms_collection_end_to_collection_start_secs = _concurrent_timer.seconds();
213 if (PrintAdaptiveSizePolicy && Verbose) {
214 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_begin: "
215 "mutator time %f", _latest_cms_collection_end_to_collection_start_secs);
216 }
217 _concurrent_timer.reset();
218 _concurrent_timer.start();
219 }
220
221 void CMSAdaptiveSizePolicy::concurrent_marking_end() {
222 if (PrintAdaptiveSizePolicy && Verbose) {
223 gclog_or_tty->stamp();
224 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_end()");
225 }
226
227 _concurrent_timer.stop();
228 _latest_cms_concurrent_marking_time_secs = _concurrent_timer.seconds();
229
230 if (PrintAdaptiveSizePolicy && Verbose) {
231 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_marking_end"
232 ":concurrent marking time (s) %f",
233 _latest_cms_concurrent_marking_time_secs);
234 }
235 }
236
237 void CMSAdaptiveSizePolicy::concurrent_precleaning_begin() {
238 if (PrintAdaptiveSizePolicy && Verbose) {
239 gclog_or_tty->stamp();
240 gclog_or_tty->print_cr(
241 "CMSAdaptiveSizePolicy::concurrent_precleaning_begin()");
242 }
243 _concurrent_timer.reset();
244 _concurrent_timer.start();
245 }
246
247
248 void CMSAdaptiveSizePolicy::concurrent_precleaning_end() {
249 if (PrintAdaptiveSizePolicy && Verbose) {
250 gclog_or_tty->stamp();
251 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_precleaning_end()");
252 }
253
254 _concurrent_timer.stop();
255 // May be set again by a second call during the same collection.
256 _latest_cms_concurrent_precleaning_time_secs = _concurrent_timer.seconds();
257
258 if (PrintAdaptiveSizePolicy && Verbose) {
259 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_precleaning_end"
260 ":concurrent precleaning time (s) %f",
261 _latest_cms_concurrent_precleaning_time_secs);
262 }
263 }
264
265 void CMSAdaptiveSizePolicy::concurrent_sweeping_begin() {
266 if (PrintAdaptiveSizePolicy && Verbose) {
267 gclog_or_tty->stamp();
268 gclog_or_tty->print_cr(
269 "CMSAdaptiveSizePolicy::concurrent_sweeping_begin()");
270 }
271 _concurrent_timer.reset();
272 _concurrent_timer.start();
273 }
274
275
276 void CMSAdaptiveSizePolicy::concurrent_sweeping_end() {
277 if (PrintAdaptiveSizePolicy && Verbose) {
278 gclog_or_tty->stamp();
279 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_sweeping_end()");
280 }
281
282 _concurrent_timer.stop();
283 _latest_cms_concurrent_sweeping_time_secs = _concurrent_timer.seconds();
284
285 if (PrintAdaptiveSizePolicy && Verbose) {
286 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_sweeping_end"
287 ":concurrent sweeping time (s) %f",
288 _latest_cms_concurrent_sweeping_time_secs);
289 }
290 }
291
292 void CMSAdaptiveSizePolicy::concurrent_phases_end(GCCause::Cause gc_cause,
293 size_t cur_eden,
294 size_t cur_promo) {
295 if (PrintAdaptiveSizePolicy && Verbose) {
296 gclog_or_tty->print(" ");
297 gclog_or_tty->stamp();
298 gclog_or_tty->print(": concurrent_phases_end ");
299 }
300
301 // Update the concurrent timer
302 _concurrent_timer.stop();
303
304 if (gc_cause != GCCause::_java_lang_system_gc ||
305 UseAdaptiveSizePolicyWithSystemGC) {
306
307 avg_cms_free()->sample(cur_promo);
308 double latest_cms_sum_concurrent_phases_time_secs =
309 concurrent_collection_time();
310
311 _avg_concurrent_time->sample(latest_cms_sum_concurrent_phases_time_secs);
312
313 // Cost of collection (unit-less)
314
315 // Total interval for collection. May not be valid. Tests
316 // below determine whether to use this.
317 //
318 if (PrintAdaptiveSizePolicy && Verbose) {
319 gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::concurrent_phases_end \n"
320 "_latest_cms_reset_end_to_initial_mark_start_secs %f \n"
321 "_latest_cms_initial_mark_start_to_end_time_secs %f \n"
322 "_latest_cms_remark_start_to_end_time_secs %f \n"
323 "_latest_cms_concurrent_marking_time_secs %f \n"
324 "_latest_cms_concurrent_precleaning_time_secs %f \n"
325 "_latest_cms_concurrent_sweeping_time_secs %f \n"
326 "latest_cms_sum_concurrent_phases_time_secs %f \n"
327 "_latest_cms_collection_end_to_collection_start_secs %f \n"
328 "concurrent_processor_fraction %f",
329 _latest_cms_reset_end_to_initial_mark_start_secs,
330 _latest_cms_initial_mark_start_to_end_time_secs,
331 _latest_cms_remark_start_to_end_time_secs,
332 _latest_cms_concurrent_marking_time_secs,
333 _latest_cms_concurrent_precleaning_time_secs,
334 _latest_cms_concurrent_sweeping_time_secs,
335 latest_cms_sum_concurrent_phases_time_secs,
336 _latest_cms_collection_end_to_collection_start_secs,
337 concurrent_processor_fraction());
338 }
339 double interval_in_seconds =
340 _latest_cms_initial_mark_start_to_end_time_secs +
341 _latest_cms_remark_start_to_end_time_secs +
342 latest_cms_sum_concurrent_phases_time_secs +
343 _latest_cms_collection_end_to_collection_start_secs;
344 assert(interval_in_seconds >= 0.0,
345 "Bad interval between cms collections");
346
347 // Sample for performance counter
348 avg_concurrent_interval()->sample(interval_in_seconds);
349
350 // STW costs (initial and remark pauses)
351 // Cost of collection (unit-less)
352 assert(_latest_cms_initial_mark_start_to_end_time_secs >= 0.0,
353 "Bad initial mark pause");
354 assert(_latest_cms_remark_start_to_end_time_secs >= 0.0,
355 "Bad remark pause");
356 double STW_time_in_seconds =
357 _latest_cms_initial_mark_start_to_end_time_secs +
358 _latest_cms_remark_start_to_end_time_secs;
359 double STW_collection_cost = 0.0;
360 if (interval_in_seconds > 0.0) {
361 // cost for the STW phases of the concurrent collection.
362 STW_collection_cost = STW_time_in_seconds / interval_in_seconds;
363 avg_cms_STW_gc_cost()->sample(STW_collection_cost);
364 }
365 if (PrintAdaptiveSizePolicy && Verbose) {
366 gclog_or_tty->print("cmsAdaptiveSizePolicy::STW_collection_end: "
367 "STW gc cost: %f average: %f", STW_collection_cost,
368 avg_cms_STW_gc_cost()->average());
369 gclog_or_tty->print_cr(" STW pause: %f (ms) STW period %f (ms)",
370 (double) STW_time_in_seconds * MILLIUNITS,
371 (double) interval_in_seconds * MILLIUNITS);
372 }
373
374 double concurrent_cost = 0.0;
375 if (latest_cms_sum_concurrent_phases_time_secs > 0.0) {
376 concurrent_cost = concurrent_collection_cost(interval_in_seconds);
377
378 avg_concurrent_gc_cost()->sample(concurrent_cost);
379 // Average this ms cost into all the other types gc costs
380
381 if (PrintAdaptiveSizePolicy && Verbose) {
382 gclog_or_tty->print("cmsAdaptiveSizePolicy::concurrent_phases_end: "
383 "concurrent gc cost: %f average: %f",
384 concurrent_cost,
385 _avg_concurrent_gc_cost->average());
386 gclog_or_tty->print_cr(" concurrent time: %f (ms) cms period %f (ms)"
387 " processor fraction: %f",
388 latest_cms_sum_concurrent_phases_time_secs * MILLIUNITS,
389 interval_in_seconds * MILLIUNITS,
390 concurrent_processor_fraction());
391 }
392 }
393 double total_collection_cost = STW_collection_cost + concurrent_cost;
394 avg_major_gc_cost()->sample(total_collection_cost);
395
396 // Gather information for estimating future behavior
397 double initial_pause_in_ms = _latest_cms_initial_mark_start_to_end_time_secs * MILLIUNITS;
398 double remark_pause_in_ms = _latest_cms_remark_start_to_end_time_secs * MILLIUNITS;
399
400 double cur_promo_size_in_mbytes = ((double)cur_promo)/((double)M);
401 initial_pause_old_estimator()->update(cur_promo_size_in_mbytes,
402 initial_pause_in_ms);
403 remark_pause_old_estimator()->update(cur_promo_size_in_mbytes,
404 remark_pause_in_ms);
405 major_collection_estimator()->update(cur_promo_size_in_mbytes,
406 total_collection_cost);
407
408 // This estimate uses the average eden size. It could also
409 // have used the latest eden size. Which is better?
410 double cur_eden_size_in_mbytes = ((double)cur_eden)/((double) M);
411 initial_pause_young_estimator()->update(cur_eden_size_in_mbytes,
412 initial_pause_in_ms);
413 remark_pause_young_estimator()->update(cur_eden_size_in_mbytes,
414 remark_pause_in_ms);
415 }
416
417 clear_internal_time_intervals();
418
419 set_first_after_collection();
420
421 // The concurrent phases keeps track of it's own mutator interval
422 // with this timer. This allows the stop-the-world phase to
423 // be included in the mutator time so that the stop-the-world time
424 // is not double counted. Reset and start it.
425 _concurrent_timer.reset();
426 _concurrent_timer.start();
427
428 // The mutator time between STW phases does not include the
429 // concurrent collection time.
430 _STW_timer.reset();
431 _STW_timer.start();
432 }
433
434 void CMSAdaptiveSizePolicy::checkpoint_roots_initial_begin() {
435 // Update the interval time
436 _STW_timer.stop();
437 _latest_cms_reset_end_to_initial_mark_start_secs = _STW_timer.seconds();
438 // Reset for the initial mark
439 _STW_timer.reset();
440 _STW_timer.start();
441 }
442
443 void CMSAdaptiveSizePolicy::checkpoint_roots_initial_end(
444 GCCause::Cause gc_cause) {
445 _STW_timer.stop();
446
447 if (gc_cause != GCCause::_java_lang_system_gc ||
448 UseAdaptiveSizePolicyWithSystemGC) {
449 _latest_cms_initial_mark_start_to_end_time_secs = _STW_timer.seconds();
450 avg_initial_pause()->sample(_latest_cms_initial_mark_start_to_end_time_secs);
451
452 if (PrintAdaptiveSizePolicy && Verbose) {
453 gclog_or_tty->print(
454 "cmsAdaptiveSizePolicy::checkpoint_roots_initial_end: "
455 "initial pause: %f ", _latest_cms_initial_mark_start_to_end_time_secs);
456 }
457 }
458
459 _STW_timer.reset();
460 _STW_timer.start();
461 }
462
463 void CMSAdaptiveSizePolicy::checkpoint_roots_final_begin() {
464 _STW_timer.stop();
465 _latest_cms_initial_mark_end_to_remark_start_secs = _STW_timer.seconds();
466 // Start accumumlating time for the remark in the STW timer.
467 _STW_timer.reset();
468 _STW_timer.start();
469 }
470
471 void CMSAdaptiveSizePolicy::checkpoint_roots_final_end(
472 GCCause::Cause gc_cause) {
473 _STW_timer.stop();
474 if (gc_cause != GCCause::_java_lang_system_gc ||
475 UseAdaptiveSizePolicyWithSystemGC) {
476 // Total initial mark pause + remark pause.
477 _latest_cms_remark_start_to_end_time_secs = _STW_timer.seconds();
478 double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs +
479 _latest_cms_remark_start_to_end_time_secs;
480 double STW_time_in_ms = STW_time_in_seconds * MILLIUNITS;
481
482 avg_remark_pause()->sample(_latest_cms_remark_start_to_end_time_secs);
483
484 // Sample total for initial mark + remark
485 avg_cms_STW_time()->sample(STW_time_in_seconds);
486
487 if (PrintAdaptiveSizePolicy && Verbose) {
488 gclog_or_tty->print("cmsAdaptiveSizePolicy::checkpoint_roots_final_end: "
489 "remark pause: %f", _latest_cms_remark_start_to_end_time_secs);
490 }
491
492 }
493 // Don't start the STW times here because the concurrent
494 // sweep and reset has not happened.
495 // Keep the old comment above in case I don't understand
496 // what is going on but now
497 // Start the STW timer because it is used by ms_collection_begin()
498 // and ms_collection_end() to get the sweep time if a MS is being
499 // done in the foreground.
500 _STW_timer.reset();
501 _STW_timer.start();
502 }
503
504 void CMSAdaptiveSizePolicy::msc_collection_begin() {
505 if (PrintAdaptiveSizePolicy && Verbose) {
506 gclog_or_tty->print(" ");
507 gclog_or_tty->stamp();
508 gclog_or_tty->print(": msc_collection_begin ");
509 }
510 _STW_timer.stop();
511 _latest_cms_msc_end_to_msc_start_time_secs = _STW_timer.seconds();
512 if (PrintAdaptiveSizePolicy && Verbose) {
513 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::msc_collection_begin: "
514 "mutator time %f",
515 _latest_cms_msc_end_to_msc_start_time_secs);
516 }
517 avg_msc_interval()->sample(_latest_cms_msc_end_to_msc_start_time_secs);
518 _STW_timer.reset();
519 _STW_timer.start();
520 }
521
522 void CMSAdaptiveSizePolicy::msc_collection_end(GCCause::Cause gc_cause) {
523 if (PrintAdaptiveSizePolicy && Verbose) {
524 gclog_or_tty->print(" ");
525 gclog_or_tty->stamp();
526 gclog_or_tty->print(": msc_collection_end ");
527 }
528 _STW_timer.stop();
529 if (gc_cause != GCCause::_java_lang_system_gc ||
530 UseAdaptiveSizePolicyWithSystemGC) {
531 double msc_pause_in_seconds = _STW_timer.seconds();
532 if ((_latest_cms_msc_end_to_msc_start_time_secs > 0.0) &&
533 (msc_pause_in_seconds > 0.0)) {
534 avg_msc_pause()->sample(msc_pause_in_seconds);
535 double mutator_time_in_seconds = 0.0;
536 if (_latest_cms_collection_end_to_collection_start_secs == 0.0) {
537 // This assertion may fail because of time stamp gradularity.
538 // Comment it out and investiage it at a later time. The large
539 // time stamp granularity occurs on some older linux systems.
540 #ifndef CLOCK_GRANULARITY_TOO_LARGE
541 assert((_latest_cms_concurrent_marking_time_secs == 0.0) &&
542 (_latest_cms_concurrent_precleaning_time_secs == 0.0) &&
543 (_latest_cms_concurrent_sweeping_time_secs == 0.0),
544 "There should not be any concurrent time");
545 #endif
546 // A concurrent collection did not start. Mutator time
547 // between collections comes from the STW MSC timer.
548 mutator_time_in_seconds = _latest_cms_msc_end_to_msc_start_time_secs;
549 } else {
550 // The concurrent collection did start so count the mutator
551 // time to the start of the concurrent collection. In this
552 // case the _latest_cms_msc_end_to_msc_start_time_secs measures
553 // the time between the initial mark or remark and the
554 // start of the MSC. That has no real meaning.
555 mutator_time_in_seconds = _latest_cms_collection_end_to_collection_start_secs;
556 }
557
558 double latest_cms_sum_concurrent_phases_time_secs =
559 concurrent_collection_time();
560 double interval_in_seconds =
561 mutator_time_in_seconds +
562 _latest_cms_initial_mark_start_to_end_time_secs +
563 _latest_cms_remark_start_to_end_time_secs +
564 latest_cms_sum_concurrent_phases_time_secs +
565 msc_pause_in_seconds;
566
567 if (PrintAdaptiveSizePolicy && Verbose) {
568 gclog_or_tty->print_cr(" interval_in_seconds %f \n"
569 " mutator_time_in_seconds %f \n"
570 " _latest_cms_initial_mark_start_to_end_time_secs %f\n"
571 " _latest_cms_remark_start_to_end_time_secs %f\n"
572 " latest_cms_sum_concurrent_phases_time_secs %f\n"
573 " msc_pause_in_seconds %f\n",
574 interval_in_seconds,
575 mutator_time_in_seconds,
576 _latest_cms_initial_mark_start_to_end_time_secs,
577 _latest_cms_remark_start_to_end_time_secs,
578 latest_cms_sum_concurrent_phases_time_secs,
579 msc_pause_in_seconds);
580 }
581
582 // The concurrent cost is wasted cost but it should be
583 // included.
584 double concurrent_cost = concurrent_collection_cost(interval_in_seconds);
585
586 // Initial mark and remark, also wasted.
587 double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs +
588 _latest_cms_remark_start_to_end_time_secs;
589 double STW_collection_cost =
590 collection_cost(STW_time_in_seconds, interval_in_seconds) +
591 concurrent_cost;
592
593 if (PrintAdaptiveSizePolicy && Verbose) {
594 gclog_or_tty->print_cr(" msc_collection_end:\n"
595 "_latest_cms_collection_end_to_collection_start_secs %f\n"
596 "_latest_cms_msc_end_to_msc_start_time_secs %f\n"
597 "_latest_cms_initial_mark_start_to_end_time_secs %f\n"
598 "_latest_cms_remark_start_to_end_time_secs %f\n"
599 "latest_cms_sum_concurrent_phases_time_secs %f\n",
600 _latest_cms_collection_end_to_collection_start_secs,
601 _latest_cms_msc_end_to_msc_start_time_secs,
602 _latest_cms_initial_mark_start_to_end_time_secs,
603 _latest_cms_remark_start_to_end_time_secs,
604 latest_cms_sum_concurrent_phases_time_secs);
605
606 gclog_or_tty->print_cr(" msc_collection_end: \n"
607 "latest_cms_sum_concurrent_phases_time_secs %f\n"
608 "STW_time_in_seconds %f\n"
609 "msc_pause_in_seconds %f\n",
610 latest_cms_sum_concurrent_phases_time_secs,
611 STW_time_in_seconds,
612 msc_pause_in_seconds);
613 }
614
615 double cost = concurrent_cost + STW_collection_cost +
616 collection_cost(msc_pause_in_seconds, interval_in_seconds);
617
618 _avg_msc_gc_cost->sample(cost);
619
620 // Average this ms cost into all the other types gc costs
621 avg_major_gc_cost()->sample(cost);
622
623 // Sample for performance counter
624 _avg_msc_interval->sample(interval_in_seconds);
625 if (PrintAdaptiveSizePolicy && Verbose) {
626 gclog_or_tty->print("cmsAdaptiveSizePolicy::msc_collection_end: "
627 "MSC gc cost: %f average: %f", cost,
628 _avg_msc_gc_cost->average());
629
630 double msc_pause_in_ms = msc_pause_in_seconds * MILLIUNITS;
631 gclog_or_tty->print_cr(" MSC pause: %f (ms) MSC period %f (ms)",
632 msc_pause_in_ms, (double) interval_in_seconds * MILLIUNITS);
633 }
634 }
635 }
636
637 clear_internal_time_intervals();
638
639 // Can this call be put into the epilogue?
640 set_first_after_collection();
641
642 // The concurrent phases keeps track of it's own mutator interval
643 // with this timer. This allows the stop-the-world phase to
644 // be included in the mutator time so that the stop-the-world time
645 // is not double counted. Reset and start it.
646 _concurrent_timer.stop();
647 _concurrent_timer.reset();
648 _concurrent_timer.start();
649
650 _STW_timer.reset();
651 _STW_timer.start();
652 }
653
654 void CMSAdaptiveSizePolicy::ms_collection_begin() {
655 if (PrintAdaptiveSizePolicy && Verbose) {
656 gclog_or_tty->print(" ");
657 gclog_or_tty->stamp();
658 gclog_or_tty->print(": ms_collection_begin ");
659 }
660 _STW_timer.stop();
661 _latest_cms_ms_end_to_ms_start = _STW_timer.seconds();
662 if (PrintAdaptiveSizePolicy && Verbose) {
663 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::ms_collection_begin: "
664 "mutator time %f",
665 _latest_cms_ms_end_to_ms_start);
666 }
667 avg_ms_interval()->sample(_STW_timer.seconds());
668 _STW_timer.reset();
669 _STW_timer.start();
670 }
671
672 void CMSAdaptiveSizePolicy::ms_collection_end(GCCause::Cause gc_cause) {
673 if (PrintAdaptiveSizePolicy && Verbose) {
674 gclog_or_tty->print(" ");
675 gclog_or_tty->stamp();
676 gclog_or_tty->print(": ms_collection_end ");
677 }
678 _STW_timer.stop();
679 if (gc_cause != GCCause::_java_lang_system_gc ||
680 UseAdaptiveSizePolicyWithSystemGC) {
681 // The MS collection is a foreground collection that does all
682 // the parts of a mostly concurrent collection.
683 //
684 // For this collection include the cost of the
685 // initial mark
686 // remark
687 // all concurrent time (scaled down by the
688 // concurrent_processor_fraction). Some
689 // may be zero if the baton was passed before
690 // it was reached.
691 // concurrent marking
692 // sweeping
693 // resetting
694 // STW after baton was passed (STW_in_foreground_in_seconds)
695 double STW_in_foreground_in_seconds = _STW_timer.seconds();
696
697 double latest_cms_sum_concurrent_phases_time_secs =
698 concurrent_collection_time();
699 if (PrintAdaptiveSizePolicy && Verbose) {
700 gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::ms_collecton_end "
701 "STW_in_foreground_in_seconds %f "
702 "_latest_cms_initial_mark_start_to_end_time_secs %f "
703 "_latest_cms_remark_start_to_end_time_secs %f "
704 "latest_cms_sum_concurrent_phases_time_secs %f "
705 "_latest_cms_ms_marking_start_to_end_time_secs %f "
706 "_latest_cms_ms_end_to_ms_start %f",
707 STW_in_foreground_in_seconds,
708 _latest_cms_initial_mark_start_to_end_time_secs,
709 _latest_cms_remark_start_to_end_time_secs,
710 latest_cms_sum_concurrent_phases_time_secs,
711 _latest_cms_ms_marking_start_to_end_time_secs,
712 _latest_cms_ms_end_to_ms_start);
713 }
714
715 double STW_marking_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs +
716 _latest_cms_remark_start_to_end_time_secs;
717 #ifndef CLOCK_GRANULARITY_TOO_LARGE
718 assert(_latest_cms_ms_marking_start_to_end_time_secs == 0.0 ||
719 latest_cms_sum_concurrent_phases_time_secs == 0.0,
720 "marking done twice?");
721 #endif
722 double ms_time_in_seconds = STW_marking_in_seconds +
723 STW_in_foreground_in_seconds +
724 _latest_cms_ms_marking_start_to_end_time_secs +
725 scaled_concurrent_collection_time();
726 avg_ms_pause()->sample(ms_time_in_seconds);
727 // Use the STW costs from the initial mark and remark plus
728 // the cost of the concurrent phase to calculate a
729 // collection cost.
730 double cost = 0.0;
731 if ((_latest_cms_ms_end_to_ms_start > 0.0) &&
732 (ms_time_in_seconds > 0.0)) {
733 double interval_in_seconds =
734 _latest_cms_ms_end_to_ms_start + ms_time_in_seconds;
735
736 if (PrintAdaptiveSizePolicy && Verbose) {
737 gclog_or_tty->print_cr("\n ms_time_in_seconds %f "
738 "latest_cms_sum_concurrent_phases_time_secs %f "
739 "interval_in_seconds %f",
740 ms_time_in_seconds,
741 latest_cms_sum_concurrent_phases_time_secs,
742 interval_in_seconds);
743 }
744
745 cost = collection_cost(ms_time_in_seconds, interval_in_seconds);
746
747 _avg_ms_gc_cost->sample(cost);
748 // Average this ms cost into all the other types gc costs
749 avg_major_gc_cost()->sample(cost);
750
751 // Sample for performance counter
752 _avg_ms_interval->sample(interval_in_seconds);
753 }
754 if (PrintAdaptiveSizePolicy && Verbose) {
755 gclog_or_tty->print("cmsAdaptiveSizePolicy::ms_collection_end: "
756 "MS gc cost: %f average: %f", cost, _avg_ms_gc_cost->average());
757
758 double ms_time_in_ms = ms_time_in_seconds * MILLIUNITS;
759 gclog_or_tty->print_cr(" MS pause: %f (ms) MS period %f (ms)",
760 ms_time_in_ms,
761 _latest_cms_ms_end_to_ms_start * MILLIUNITS);
762 }
763 }
764
765 // Consider putting this code (here to end) into a
766 // method for convenience.
767 clear_internal_time_intervals();
768
769 set_first_after_collection();
770
771 // The concurrent phases keeps track of it's own mutator interval
772 // with this timer. This allows the stop-the-world phase to
773 // be included in the mutator time so that the stop-the-world time
774 // is not double counted. Reset and start it.
775 _concurrent_timer.stop();
776 _concurrent_timer.reset();
777 _concurrent_timer.start();
778
779 _STW_timer.reset();
780 _STW_timer.start();
781 }
782
783 void CMSAdaptiveSizePolicy::clear_internal_time_intervals() {
784 _latest_cms_reset_end_to_initial_mark_start_secs = 0.0;
785 _latest_cms_initial_mark_end_to_remark_start_secs = 0.0;
786 _latest_cms_collection_end_to_collection_start_secs = 0.0;
787 _latest_cms_concurrent_marking_time_secs = 0.0;
788 _latest_cms_concurrent_precleaning_time_secs = 0.0;
789 _latest_cms_concurrent_sweeping_time_secs = 0.0;
790 _latest_cms_msc_end_to_msc_start_time_secs = 0.0;
791 _latest_cms_ms_end_to_ms_start = 0.0;
792 _latest_cms_remark_start_to_end_time_secs = 0.0;
793 _latest_cms_initial_mark_start_to_end_time_secs = 0.0;
794 _latest_cms_ms_marking_start_to_end_time_secs = 0.0;
795 }
796
797 void CMSAdaptiveSizePolicy::clear_generation_free_space_flags() {
798 AdaptiveSizePolicy::clear_generation_free_space_flags();
799
800 set_change_young_gen_for_maj_pauses(0);
801 }
802
803 void CMSAdaptiveSizePolicy::concurrent_phases_resume() {
804 if (PrintAdaptiveSizePolicy && Verbose) {
805 gclog_or_tty->stamp();
806 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_phases_resume()");
807 }
808 _concurrent_timer.start();
809 }
810
811 double CMSAdaptiveSizePolicy::time_since_major_gc() const {
812 _concurrent_timer.stop();
813 double time_since_cms_gc = _concurrent_timer.seconds();
814 _concurrent_timer.start();
815 _STW_timer.stop();
816 double time_since_STW_gc = _STW_timer.seconds();
817 _STW_timer.start();
818
819 return MIN2(time_since_cms_gc, time_since_STW_gc);
820 }
821
822 double CMSAdaptiveSizePolicy::major_gc_interval_average_for_decay() const {
823 double cms_interval = _avg_concurrent_interval->average();
824 double msc_interval = _avg_msc_interval->average();
825 double ms_interval = _avg_ms_interval->average();
826
827 return MAX3(cms_interval, msc_interval, ms_interval);
828 }
829
830 double CMSAdaptiveSizePolicy::cms_gc_cost() const {
831 return avg_major_gc_cost()->average();
832 }
833
834 void CMSAdaptiveSizePolicy::ms_collection_marking_begin() {
835 _STW_timer.stop();
836 // Start accumumlating time for the marking in the STW timer.
837 _STW_timer.reset();
838 _STW_timer.start();
839 }
840
841 void CMSAdaptiveSizePolicy::ms_collection_marking_end(
842 GCCause::Cause gc_cause) {
843 _STW_timer.stop();
844 if (gc_cause != GCCause::_java_lang_system_gc ||
845 UseAdaptiveSizePolicyWithSystemGC) {
846 _latest_cms_ms_marking_start_to_end_time_secs = _STW_timer.seconds();
847 if (PrintAdaptiveSizePolicy && Verbose) {
848 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::"
849 "msc_collection_marking_end: mutator time %f",
850 _latest_cms_ms_marking_start_to_end_time_secs);
851 }
852 }
853 _STW_timer.reset();
854 _STW_timer.start();
855 }
856
857 double CMSAdaptiveSizePolicy::gc_cost() const {
858 double cms_gen_cost = cms_gc_cost();
859 double result = MIN2(1.0, minor_gc_cost() + cms_gen_cost);
860 assert(result >= 0.0, "Both minor and major costs are non-negative");
861 return result;
862 }
863
864 // Cost of collection (unit-less)
865 double CMSAdaptiveSizePolicy::collection_cost(double pause_in_seconds,
866 double interval_in_seconds) {
867 // Cost of collection (unit-less)
868 double cost = 0.0;
869 if ((interval_in_seconds > 0.0) &&
870 (pause_in_seconds > 0.0)) {
871 cost =
872 pause_in_seconds / interval_in_seconds;
873 }
874 return cost;
875 }
876
877 size_t CMSAdaptiveSizePolicy::adjust_eden_for_pause_time(size_t cur_eden) {
878 size_t change = 0;
879 size_t desired_eden = cur_eden;
880
881 // reduce eden size
882 change = eden_decrement_aligned_down(cur_eden);
883 desired_eden = cur_eden - change;
884
885 if (PrintAdaptiveSizePolicy && Verbose) {
886 gclog_or_tty->print_cr(
887 "CMSAdaptiveSizePolicy::adjust_eden_for_pause_time "
888 "adjusting eden for pause time. "
889 " starting eden size " SIZE_FORMAT
890 " reduced eden size " SIZE_FORMAT
891 " eden delta " SIZE_FORMAT,
892 cur_eden, desired_eden, change);
893 }
894
895 return desired_eden;
896 }
897
898 size_t CMSAdaptiveSizePolicy::adjust_eden_for_throughput(size_t cur_eden) {
899
900 size_t desired_eden = cur_eden;
901
902 set_change_young_gen_for_throughput(increase_young_gen_for_througput_true);
903
904 size_t change = eden_increment_aligned_up(cur_eden);
905 size_t scaled_change = scale_by_gen_gc_cost(change, minor_gc_cost());
906
907 if (cur_eden + scaled_change > cur_eden) {
908 desired_eden = cur_eden + scaled_change;
909 }
910
911 _young_gen_change_for_minor_throughput++;
912
913 if (PrintAdaptiveSizePolicy && Verbose) {
914 gclog_or_tty->print_cr(
915 "CMSAdaptiveSizePolicy::adjust_eden_for_throughput "
916 "adjusting eden for throughput. "
917 " starting eden size " SIZE_FORMAT
918 " increased eden size " SIZE_FORMAT
919 " eden delta " SIZE_FORMAT,
920 cur_eden, desired_eden, scaled_change);
921 }
922
923 return desired_eden;
924 }
925
926 size_t CMSAdaptiveSizePolicy::adjust_eden_for_footprint(size_t cur_eden) {
927
928 set_decrease_for_footprint(decrease_young_gen_for_footprint_true);
929
930 size_t change = eden_decrement(cur_eden);
931 size_t desired_eden_size = cur_eden - change;
932
933 if (PrintAdaptiveSizePolicy && Verbose) {
934 gclog_or_tty->print_cr(
935 "CMSAdaptiveSizePolicy::adjust_eden_for_footprint "
936 "adjusting eden for footprint. "
937 " starting eden size " SIZE_FORMAT
938 " reduced eden size " SIZE_FORMAT
939 " eden delta " SIZE_FORMAT,
940 cur_eden, desired_eden_size, change);
941 }
942 return desired_eden_size;
943 }
944
945 // The eden and promo versions should be combined if possible.
946 // They are the same except that the sizes of the decrement
947 // and increment are different for eden and promo.
948 size_t CMSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) {
949 size_t delta = eden_decrement(cur_eden);
950 return align_size_down(delta, generation_alignment());
951 }
952
953 size_t CMSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) {
954 size_t delta = eden_increment(cur_eden);
955 return align_size_up(delta, generation_alignment());
956 }
957
958 size_t CMSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) {
959 size_t delta = promo_decrement(cur_promo);
960 return align_size_down(delta, generation_alignment());
961 }
962
963 size_t CMSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) {
964 size_t delta = promo_increment(cur_promo);
965 return align_size_up(delta, generation_alignment());
966 }
967
968
969 void CMSAdaptiveSizePolicy::compute_young_generation_free_space(size_t cur_eden,
970 size_t max_eden_size)
971 {
972 size_t desired_eden_size = cur_eden;
973 size_t eden_limit = max_eden_size;
974
975 // Printout input
976 if (PrintGC && PrintAdaptiveSizePolicy) {
977 gclog_or_tty->print_cr(
978 "CMSAdaptiveSizePolicy::compute_young_generation_free_space: "
979 "cur_eden " SIZE_FORMAT,
980 cur_eden);
981 }
982
983 // Used for diagnostics
984 clear_generation_free_space_flags();
985
986 if (_avg_minor_pause->padded_average() > gc_pause_goal_sec()) {
987 if (minor_pause_young_estimator()->decrement_will_decrease()) {
988 // If the minor pause is too long, shrink the young gen.
989 set_change_young_gen_for_min_pauses(
990 decrease_young_gen_for_min_pauses_true);
991 desired_eden_size = adjust_eden_for_pause_time(desired_eden_size);
992 }
993 } else if ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) ||
994 (avg_initial_pause()->padded_average() > gc_pause_goal_sec())) {
995 // The remark or initial pauses are not meeting the goal. Should
996 // the generation be shrunk?
997 if (get_and_clear_first_after_collection() &&
998 ((avg_remark_pause()->padded_average() > gc_pause_goal_sec() &&
999 remark_pause_young_estimator()->decrement_will_decrease()) ||
1000 (avg_initial_pause()->padded_average() > gc_pause_goal_sec() &&
1001 initial_pause_young_estimator()->decrement_will_decrease()))) {
1002
1003 set_change_young_gen_for_maj_pauses(
1004 decrease_young_gen_for_maj_pauses_true);
1005
1006 // If the remark or initial pause is too long and this is the
1007 // first young gen collection after a cms collection, shrink
1008 // the young gen.
1009 desired_eden_size = adjust_eden_for_pause_time(desired_eden_size);
1010 }
1011 // If not the first young gen collection after a cms collection,
1012 // don't do anything. In this case an adjustment has already
1013 // been made and the results of the adjustment has not yet been
1014 // measured.
1015 } else if ((minor_gc_cost() >= 0.0) &&
1016 (adjusted_mutator_cost() < _throughput_goal)) {
1017 desired_eden_size = adjust_eden_for_throughput(desired_eden_size);
1018 } else {
1019 desired_eden_size = adjust_eden_for_footprint(desired_eden_size);
1020 }
1021
1022 if (PrintGC && PrintAdaptiveSizePolicy) {
1023 gclog_or_tty->print_cr(
1024 "CMSAdaptiveSizePolicy::compute_young_generation_free_space limits:"
1025 " desired_eden_size: " SIZE_FORMAT
1026 " old_eden_size: " SIZE_FORMAT,
1027 desired_eden_size, cur_eden);
1028 }
1029
1030 set_eden_size(desired_eden_size);
1031 }
1032
1033 size_t CMSAdaptiveSizePolicy::adjust_promo_for_pause_time(size_t cur_promo) {
1034 size_t change = 0;
1035 size_t desired_promo = cur_promo;
1036 // Move this test up to caller like the adjust_eden_for_pause_time()
1037 // call.
1038 if ((AdaptiveSizePausePolicy == 0) &&
1039 ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) ||
1040 (avg_initial_pause()->padded_average() > gc_pause_goal_sec()))) {
1041 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true);
1042 change = promo_decrement_aligned_down(cur_promo);
1043 desired_promo = cur_promo - change;
1044 } else if ((AdaptiveSizePausePolicy > 0) &&
1045 (((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) &&
1046 remark_pause_old_estimator()->decrement_will_decrease()) ||
1047 ((avg_initial_pause()->padded_average() > gc_pause_goal_sec()) &&
1048 initial_pause_old_estimator()->decrement_will_decrease()))) {
1049 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true);
1050 change = promo_decrement_aligned_down(cur_promo);
1051 desired_promo = cur_promo - change;
1052 }
1053
1054 if ((change != 0) &&PrintAdaptiveSizePolicy && Verbose) {
1055 gclog_or_tty->print_cr(
1056 "CMSAdaptiveSizePolicy::adjust_promo_for_pause_time "
1057 "adjusting promo for pause time. "
1058 " starting promo size " SIZE_FORMAT
1059 " reduced promo size " SIZE_FORMAT
1060 " promo delta " SIZE_FORMAT,
1061 cur_promo, desired_promo, change);
1062 }
1063
1064 return desired_promo;
1065 }
1066
1067 // Try to share this with PS.
1068 size_t CMSAdaptiveSizePolicy::scale_by_gen_gc_cost(size_t base_change,
1069 double gen_gc_cost) {
1070
1071 // Calculate the change to use for the tenured gen.
1072 size_t scaled_change = 0;
1073 // Can the increment to the generation be scaled?
1074 if (gc_cost() >= 0.0 && gen_gc_cost >= 0.0) {
1075 double scale_by_ratio = gen_gc_cost / gc_cost();
1076 scaled_change =
1077 (size_t) (scale_by_ratio * (double) base_change);
1078 if (PrintAdaptiveSizePolicy && Verbose) {
1079 gclog_or_tty->print_cr(
1080 "Scaled tenured increment: " SIZE_FORMAT " by %f down to "
1081 SIZE_FORMAT,
1082 base_change, scale_by_ratio, scaled_change);
1083 }
1084 } else if (gen_gc_cost >= 0.0) {
1085 // Scaling is not going to work. If the major gc time is the
1086 // larger than the other GC costs, give it a full increment.
1087 if (gen_gc_cost >= (gc_cost() - gen_gc_cost)) {
1088 scaled_change = base_change;
1089 }
1090 } else {
1091 // Don't expect to get here but it's ok if it does
1092 // in the product build since the delta will be 0
1093 // and nothing will change.
1094 assert(false, "Unexpected value for gc costs");
1095 }
1096
1097 return scaled_change;
1098 }
1099
1100 size_t CMSAdaptiveSizePolicy::adjust_promo_for_throughput(size_t cur_promo) {
1101
1102 size_t desired_promo = cur_promo;
1103
1104 set_change_old_gen_for_throughput(increase_old_gen_for_throughput_true);
1105
1106 size_t change = promo_increment_aligned_up(cur_promo);
1107 size_t scaled_change = scale_by_gen_gc_cost(change, major_gc_cost());
1108
1109 if (cur_promo + scaled_change > cur_promo) {
1110 desired_promo = cur_promo + scaled_change;
1111 }
1112
1113 _old_gen_change_for_major_throughput++;
1114
1115 if (PrintAdaptiveSizePolicy && Verbose) {
1116 gclog_or_tty->print_cr(
1117 "CMSAdaptiveSizePolicy::adjust_promo_for_throughput "
1118 "adjusting promo for throughput. "
1119 " starting promo size " SIZE_FORMAT
1120 " increased promo size " SIZE_FORMAT
1121 " promo delta " SIZE_FORMAT,
1122 cur_promo, desired_promo, scaled_change);
1123 }
1124
1125 return desired_promo;
1126 }
1127
1128 size_t CMSAdaptiveSizePolicy::adjust_promo_for_footprint(size_t cur_promo,
1129 size_t cur_eden) {
1130
1131 set_decrease_for_footprint(decrease_young_gen_for_footprint_true);
1132
1133 size_t change = promo_decrement(cur_promo);
1134 size_t desired_promo_size = cur_promo - change;
1135
1136 if (PrintAdaptiveSizePolicy && Verbose) {
1137 gclog_or_tty->print_cr(
1138 "CMSAdaptiveSizePolicy::adjust_promo_for_footprint "
1139 "adjusting promo for footprint. "
1140 " starting promo size " SIZE_FORMAT
1141 " reduced promo size " SIZE_FORMAT
1142 " promo delta " SIZE_FORMAT,
1143 cur_promo, desired_promo_size, change);
1144 }
1145 return desired_promo_size;
1146 }
1147
1148 void CMSAdaptiveSizePolicy::compute_tenured_generation_free_space(
1149 size_t cur_tenured_free,
1150 size_t max_tenured_available,
1151 size_t cur_eden) {
1152 // This can be bad if the desired value grows/shrinks without
1153 // any connection to the read free space
1154 size_t desired_promo_size = promo_size();
1155 size_t tenured_limit = max_tenured_available;
1156
1157 // Printout input
1158 if (PrintGC && PrintAdaptiveSizePolicy) {
1159 gclog_or_tty->print_cr(
1160 "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space: "
1161 "cur_tenured_free " SIZE_FORMAT
1162 " max_tenured_available " SIZE_FORMAT,
1163 cur_tenured_free, max_tenured_available);
1164 }
1165
1166 // Used for diagnostics
1167 clear_generation_free_space_flags();
1168
1169 set_decide_at_full_gc(decide_at_full_gc_true);
1170 if (avg_remark_pause()->padded_average() > gc_pause_goal_sec() ||
1171 avg_initial_pause()->padded_average() > gc_pause_goal_sec()) {
1172 desired_promo_size = adjust_promo_for_pause_time(cur_tenured_free);
1173 } else if (avg_minor_pause()->padded_average() > gc_pause_goal_sec()) {
1174 // Nothing to do since the minor collections are too large and
1175 // this method only deals with the cms generation.
1176 } else if ((cms_gc_cost() >= 0.0) &&
1177 (adjusted_mutator_cost() < _throughput_goal)) {
1178 desired_promo_size = adjust_promo_for_throughput(cur_tenured_free);
1179 } else {
1180 desired_promo_size = adjust_promo_for_footprint(cur_tenured_free,
1181 cur_eden);
1182 }
1183
1184 if (PrintGC && PrintAdaptiveSizePolicy) {
1185 gclog_or_tty->print_cr(
1186 "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space limits:"
1187 " desired_promo_size: " SIZE_FORMAT
1188 " old_promo_size: " SIZE_FORMAT,
1189 desired_promo_size, cur_tenured_free);
1190 }
1191
1192 set_promo_size(desired_promo_size);
1193 }
1194
1195 int CMSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold(
1196 bool is_survivor_overflow,
1197 int tenuring_threshold,
1198 size_t survivor_limit) {
1199 assert(survivor_limit >= generation_alignment(),
1200 "survivor_limit too small");
1201 assert((size_t)align_size_down(survivor_limit, generation_alignment())
1202 == survivor_limit, "survivor_limit not aligned");
1203
1204 // Change UsePSAdaptiveSurvivorSizePolicy -> UseAdaptiveSurvivorSizePolicy?
1205 if (!UsePSAdaptiveSurvivorSizePolicy ||
1206 !young_gen_policy_is_ready()) {
1207 return tenuring_threshold;
1208 }
1209
1210 // We'll decide whether to increase or decrease the tenuring
1211 // threshold based partly on the newly computed survivor size
1212 // (if we hit the maximum limit allowed, we'll always choose to
1213 // decrement the threshold).
1214 bool incr_tenuring_threshold = false;
1215 bool decr_tenuring_threshold = false;
1216
1217 set_decrement_tenuring_threshold_for_gc_cost(false);
1218 set_increment_tenuring_threshold_for_gc_cost(false);
1219 set_decrement_tenuring_threshold_for_survivor_limit(false);
1220
1221 if (!is_survivor_overflow) {
1222 // Keep running averages on how much survived
1223
1224 // We use the tenuring threshold to equalize the cost of major
1225 // and minor collections.
1226 // ThresholdTolerance is used to indicate how sensitive the
1227 // tenuring threshold is to differences in cost betweent the
1228 // collection types.
1229
1230 // Get the times of interest. This involves a little work, so
1231 // we cache the values here.
1232 const double major_cost = major_gc_cost();
1233 const double minor_cost = minor_gc_cost();
1234
1235 if (minor_cost > major_cost * _threshold_tolerance_percent) {
1236 // Minor times are getting too long; lower the threshold so
1237 // less survives and more is promoted.
1238 decr_tenuring_threshold = true;
1239 set_decrement_tenuring_threshold_for_gc_cost(true);
1240 } else if (major_cost > minor_cost * _threshold_tolerance_percent) {
1241 // Major times are too long, so we want less promotion.
1242 incr_tenuring_threshold = true;
1243 set_increment_tenuring_threshold_for_gc_cost(true);
1244 }
1245
1246 } else {
1247 // Survivor space overflow occurred, so promoted and survived are
1248 // not accurate. We'll make our best guess by combining survived
1249 // and promoted and count them as survivors.
1250 //
1251 // We'll lower the tenuring threshold to see if we can correct
1252 // things. Also, set the survivor size conservatively. We're
1253 // trying to avoid many overflows from occurring if defnew size
1254 // is just too small.
1255
1256 decr_tenuring_threshold = true;
1257 }
1258
1259 // The padded average also maintains a deviation from the average;
1260 // we use this to see how good of an estimate we have of what survived.
1261 // We're trying to pad the survivor size as little as possible without
1262 // overflowing the survivor spaces.
1263 size_t target_size = align_size_up((size_t)_avg_survived->padded_average(),
1264 generation_alignment());
1265 target_size = MAX2(target_size, generation_alignment());
1266
1267 if (target_size > survivor_limit) {
1268 // Target size is bigger than we can handle. Let's also reduce
1269 // the tenuring threshold.
1270 target_size = survivor_limit;
1271 decr_tenuring_threshold = true;
1272 set_decrement_tenuring_threshold_for_survivor_limit(true);
1273 }
1274
1275 // Finally, increment or decrement the tenuring threshold, as decided above.
1276 // We test for decrementing first, as we might have hit the target size
1277 // limit.
1278 if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1279 if (tenuring_threshold > 1) {
1280 tenuring_threshold--;
1281 }
1282 } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1283 if (tenuring_threshold < MaxTenuringThreshold) {
1284 tenuring_threshold++;
1285 }
1286 }
1287
1288 // We keep a running average of the amount promoted which is used
1289 // to decide when we should collect the old generation (when
1290 // the amount of old gen free space is less than what we expect to
1291 // promote).
1292
1293 if (PrintAdaptiveSizePolicy) {
1294 // A little more detail if Verbose is on
1295 GenCollectedHeap* gch = GenCollectedHeap::heap();
1296 if (Verbose) {
1297 gclog_or_tty->print( " avg_survived: %f"
1298 " avg_deviation: %f",
1299 _avg_survived->average(),
1300 _avg_survived->deviation());
1301 }
1302
1303 gclog_or_tty->print( " avg_survived_padded_avg: %f",
1304 _avg_survived->padded_average());
1305
1306 if (Verbose) {
1307 gclog_or_tty->print( " avg_promoted_avg: %f"
1308 " avg_promoted_dev: %f",
1309 gch->gc_stats(1)->avg_promoted()->average(),
1310 gch->gc_stats(1)->avg_promoted()->deviation());
1311 }
1312
1313 gclog_or_tty->print( " avg_promoted_padded_avg: %f"
1314 " avg_pretenured_padded_avg: %f"
1315 " tenuring_thresh: %d"
1316 " target_size: " SIZE_FORMAT
1317 " survivor_limit: " SIZE_FORMAT,
1318 gch->gc_stats(1)->avg_promoted()->padded_average(),
1319 _avg_pretenured->padded_average(),
1320 tenuring_threshold, target_size, survivor_limit);
1321 gclog_or_tty->cr();
1322 }
1323
1324 set_survivor_size(target_size);
1325
1326 return tenuring_threshold;
1327 }
1328
1329 bool CMSAdaptiveSizePolicy::get_and_clear_first_after_collection() {
1330 bool result = _first_after_collection;
1331 _first_after_collection = false;
1332 return result;
1333 }
1334
1335 bool CMSAdaptiveSizePolicy::print_adaptive_size_policy_on(
1336 outputStream* st) const {
1337
1338 if (!UseAdaptiveSizePolicy) return false;
1339
1340 GenCollectedHeap* gch = GenCollectedHeap::heap();
1341 Generation* gen0 = gch->get_gen(0);
1342 DefNewGeneration* def_new = gen0->as_DefNewGeneration();
1343 return
1344 AdaptiveSizePolicy::print_adaptive_size_policy_on(
1345 st,
1346 def_new->tenuring_threshold());
1347 }