1 /* 2 * Copyright (c) 2004, 2013, 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 #ifdef TARGET_OS_FAMILY_aix 41 # include "os_aix.inline.hpp" 42 #endif 43 #ifdef TARGET_OS_FAMILY_bsd 44 # include "os_bsd.inline.hpp" 45 #endif 46 elapsedTimer CMSAdaptiveSizePolicy::_concurrent_timer; 47 elapsedTimer CMSAdaptiveSizePolicy::_STW_timer; 48 49 // Defined if the granularity of the time measurements is potentially too large. 50 #define CLOCK_GRANULARITY_TOO_LARGE 51 52 CMSAdaptiveSizePolicy::CMSAdaptiveSizePolicy(size_t init_eden_size, 53 size_t init_promo_size, 54 size_t init_survivor_size, 55 double max_gc_minor_pause_sec, 56 double max_gc_pause_sec, 57 uint gc_cost_ratio) : 58 AdaptiveSizePolicy(init_eden_size, 59 init_promo_size, 60 init_survivor_size, 61 max_gc_pause_sec, 62 gc_cost_ratio) { 63 64 clear_internal_time_intervals(); 65 66 _processor_count = os::active_processor_count(); 67 68 if (CMSConcurrentMTEnabled && (ConcGCThreads > 1)) { 69 assert(_processor_count > 0, "Processor count is suspect"); 70 _concurrent_processor_count = MIN2((uint) ConcGCThreads, 71 (uint) _processor_count); 72 } else { 73 _concurrent_processor_count = 1; 74 } 75 76 _avg_concurrent_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 77 _avg_concurrent_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 78 _avg_concurrent_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 79 80 _avg_initial_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight, 81 PausePadding); 82 _avg_remark_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight, 83 PausePadding); 84 85 _avg_cms_STW_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 86 _avg_cms_STW_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 87 88 _avg_cms_free = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 89 _avg_cms_free_at_sweep = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 90 _avg_cms_promo = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 91 92 // Mark-sweep-compact 93 _avg_msc_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 94 _avg_msc_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 95 _avg_msc_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 96 97 // Mark-sweep 98 _avg_ms_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 99 _avg_ms_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 100 _avg_ms_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 101 102 // Variables that estimate pause times as a function of generation 103 // size. 104 _remark_pause_old_estimator = 105 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 106 _initial_pause_old_estimator = 107 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 108 _remark_pause_young_estimator = 109 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 110 _initial_pause_young_estimator = 111 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 112 113 // Alignment comes from that used in ReservedSpace. 114 _generation_alignment = os::vm_allocation_granularity(); 115 116 // Start the concurrent timer here so that the first 117 // concurrent_phases_begin() measures a finite mutator 118 // time. A finite mutator time is used to determine 119 // if a concurrent collection has been started. If this 120 // proves to be a problem, use some explicit flag to 121 // signal that a concurrent collection has been started. 122 _concurrent_timer.start(); 123 _STW_timer.start(); 124 } 125 126 double CMSAdaptiveSizePolicy::concurrent_processor_fraction() { 127 // For now assume no other daemon threads are taking alway 128 // cpu's from the application. 129 return ((double) _concurrent_processor_count / (double) _processor_count); 130 } 131 132 double CMSAdaptiveSizePolicy::concurrent_collection_cost( 133 double interval_in_seconds) { 134 // When the precleaning and sweeping phases use multiple 135 // threads, change one_processor_fraction to 136 // concurrent_processor_fraction(). 137 double one_processor_fraction = 1.0 / ((double) processor_count()); 138 double concurrent_cost = 139 collection_cost(_latest_cms_concurrent_marking_time_secs, 140 interval_in_seconds) * concurrent_processor_fraction() + 141 collection_cost(_latest_cms_concurrent_precleaning_time_secs, 142 interval_in_seconds) * one_processor_fraction + 143 collection_cost(_latest_cms_concurrent_sweeping_time_secs, 144 interval_in_seconds) * one_processor_fraction; 145 if (PrintAdaptiveSizePolicy && Verbose) { 146 gclog_or_tty->print_cr( 147 "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_cost(%f) " 148 "_latest_cms_concurrent_marking_cost %f " 149 "_latest_cms_concurrent_precleaning_cost %f " 150 "_latest_cms_concurrent_sweeping_cost %f " 151 "concurrent_processor_fraction %f " 152 "concurrent_cost %f ", 153 interval_in_seconds, 154 collection_cost(_latest_cms_concurrent_marking_time_secs, 155 interval_in_seconds), 156 collection_cost(_latest_cms_concurrent_precleaning_time_secs, 157 interval_in_seconds), 158 collection_cost(_latest_cms_concurrent_sweeping_time_secs, 159 interval_in_seconds), 160 concurrent_processor_fraction(), 161 concurrent_cost); 162 } 163 return concurrent_cost; 164 } 165 166 double CMSAdaptiveSizePolicy::concurrent_collection_time() { 167 double latest_cms_sum_concurrent_phases_time_secs = 168 _latest_cms_concurrent_marking_time_secs + 169 _latest_cms_concurrent_precleaning_time_secs + 170 _latest_cms_concurrent_sweeping_time_secs; 171 return latest_cms_sum_concurrent_phases_time_secs; 172 } 173 174 double CMSAdaptiveSizePolicy::scaled_concurrent_collection_time() { 175 // When the precleaning and sweeping phases use multiple 176 // threads, change one_processor_fraction to 177 // concurrent_processor_fraction(). 178 double one_processor_fraction = 1.0 / ((double) processor_count()); 179 double latest_cms_sum_concurrent_phases_time_secs = 180 _latest_cms_concurrent_marking_time_secs * concurrent_processor_fraction() + 181 _latest_cms_concurrent_precleaning_time_secs * one_processor_fraction + 182 _latest_cms_concurrent_sweeping_time_secs * one_processor_fraction ; 183 if (PrintAdaptiveSizePolicy && Verbose) { 184 gclog_or_tty->print_cr( 185 "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_time " 186 "_latest_cms_concurrent_marking_time_secs %f " 187 "_latest_cms_concurrent_precleaning_time_secs %f " 188 "_latest_cms_concurrent_sweeping_time_secs %f " 189 "concurrent_processor_fraction %f " 190 "latest_cms_sum_concurrent_phases_time_secs %f ", 191 _latest_cms_concurrent_marking_time_secs, 192 _latest_cms_concurrent_precleaning_time_secs, 193 _latest_cms_concurrent_sweeping_time_secs, 194 concurrent_processor_fraction(), 195 latest_cms_sum_concurrent_phases_time_secs); 196 } 197 return latest_cms_sum_concurrent_phases_time_secs; 198 } 199 200 void CMSAdaptiveSizePolicy::update_minor_pause_old_estimator( 201 double minor_pause_in_ms) { 202 // Get the equivalent of the free space 203 // that is available for promotions in the CMS generation 204 // and use that to update _minor_pause_old_estimator 205 206 // Don't implement this until it is needed. A warning is 207 // printed if _minor_pause_old_estimator is used. 208 } 209 210 void CMSAdaptiveSizePolicy::concurrent_marking_begin() { 211 if (PrintAdaptiveSizePolicy && Verbose) { 212 gclog_or_tty->print(" "); 213 gclog_or_tty->stamp(); 214 gclog_or_tty->print(": concurrent_marking_begin "); 215 } 216 // Update the interval time 217 _concurrent_timer.stop(); 218 _latest_cms_collection_end_to_collection_start_secs = _concurrent_timer.seconds(); 219 if (PrintAdaptiveSizePolicy && Verbose) { 220 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_begin: " 221 "mutator time %f", _latest_cms_collection_end_to_collection_start_secs); 222 } 223 _concurrent_timer.reset(); 224 _concurrent_timer.start(); 225 } 226 227 void CMSAdaptiveSizePolicy::concurrent_marking_end() { 228 if (PrintAdaptiveSizePolicy && Verbose) { 229 gclog_or_tty->stamp(); 230 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_end()"); 231 } 232 233 _concurrent_timer.stop(); 234 _latest_cms_concurrent_marking_time_secs = _concurrent_timer.seconds(); 235 236 if (PrintAdaptiveSizePolicy && Verbose) { 237 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_marking_end" 238 ":concurrent marking time (s) %f", 239 _latest_cms_concurrent_marking_time_secs); 240 } 241 } 242 243 void CMSAdaptiveSizePolicy::concurrent_precleaning_begin() { 244 if (PrintAdaptiveSizePolicy && Verbose) { 245 gclog_or_tty->stamp(); 246 gclog_or_tty->print_cr( 247 "CMSAdaptiveSizePolicy::concurrent_precleaning_begin()"); 248 } 249 _concurrent_timer.reset(); 250 _concurrent_timer.start(); 251 } 252 253 254 void CMSAdaptiveSizePolicy::concurrent_precleaning_end() { 255 if (PrintAdaptiveSizePolicy && Verbose) { 256 gclog_or_tty->stamp(); 257 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_precleaning_end()"); 258 } 259 260 _concurrent_timer.stop(); 261 // May be set again by a second call during the same collection. 262 _latest_cms_concurrent_precleaning_time_secs = _concurrent_timer.seconds(); 263 264 if (PrintAdaptiveSizePolicy && Verbose) { 265 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_precleaning_end" 266 ":concurrent precleaning time (s) %f", 267 _latest_cms_concurrent_precleaning_time_secs); 268 } 269 } 270 271 void CMSAdaptiveSizePolicy::concurrent_sweeping_begin() { 272 if (PrintAdaptiveSizePolicy && Verbose) { 273 gclog_or_tty->stamp(); 274 gclog_or_tty->print_cr( 275 "CMSAdaptiveSizePolicy::concurrent_sweeping_begin()"); 276 } 277 _concurrent_timer.reset(); 278 _concurrent_timer.start(); 279 } 280 281 282 void CMSAdaptiveSizePolicy::concurrent_sweeping_end() { 283 if (PrintAdaptiveSizePolicy && Verbose) { 284 gclog_or_tty->stamp(); 285 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_sweeping_end()"); 286 } 287 288 _concurrent_timer.stop(); 289 _latest_cms_concurrent_sweeping_time_secs = _concurrent_timer.seconds(); 290 291 if (PrintAdaptiveSizePolicy && Verbose) { 292 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_sweeping_end" 293 ":concurrent sweeping time (s) %f", 294 _latest_cms_concurrent_sweeping_time_secs); 295 } 296 } 297 298 void CMSAdaptiveSizePolicy::concurrent_phases_end(GCCause::Cause gc_cause, 299 size_t cur_eden, 300 size_t cur_promo) { 301 if (PrintAdaptiveSizePolicy && Verbose) { 302 gclog_or_tty->print(" "); 303 gclog_or_tty->stamp(); 304 gclog_or_tty->print(": concurrent_phases_end "); 305 } 306 307 // Update the concurrent timer 308 _concurrent_timer.stop(); 309 310 if (gc_cause != GCCause::_java_lang_system_gc || 311 UseAdaptiveSizePolicyWithSystemGC) { 312 313 avg_cms_free()->sample(cur_promo); 314 double latest_cms_sum_concurrent_phases_time_secs = 315 concurrent_collection_time(); 316 317 _avg_concurrent_time->sample(latest_cms_sum_concurrent_phases_time_secs); 318 319 // Cost of collection (unit-less) 320 321 // Total interval for collection. May not be valid. Tests 322 // below determine whether to use this. 323 // 324 if (PrintAdaptiveSizePolicy && Verbose) { 325 gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::concurrent_phases_end \n" 326 "_latest_cms_reset_end_to_initial_mark_start_secs %f \n" 327 "_latest_cms_initial_mark_start_to_end_time_secs %f \n" 328 "_latest_cms_remark_start_to_end_time_secs %f \n" 329 "_latest_cms_concurrent_marking_time_secs %f \n" 330 "_latest_cms_concurrent_precleaning_time_secs %f \n" 331 "_latest_cms_concurrent_sweeping_time_secs %f \n" 332 "latest_cms_sum_concurrent_phases_time_secs %f \n" 333 "_latest_cms_collection_end_to_collection_start_secs %f \n" 334 "concurrent_processor_fraction %f", 335 _latest_cms_reset_end_to_initial_mark_start_secs, 336 _latest_cms_initial_mark_start_to_end_time_secs, 337 _latest_cms_remark_start_to_end_time_secs, 338 _latest_cms_concurrent_marking_time_secs, 339 _latest_cms_concurrent_precleaning_time_secs, 340 _latest_cms_concurrent_sweeping_time_secs, 341 latest_cms_sum_concurrent_phases_time_secs, 342 _latest_cms_collection_end_to_collection_start_secs, 343 concurrent_processor_fraction()); 344 } 345 double interval_in_seconds = 346 _latest_cms_initial_mark_start_to_end_time_secs + 347 _latest_cms_remark_start_to_end_time_secs + 348 latest_cms_sum_concurrent_phases_time_secs + 349 _latest_cms_collection_end_to_collection_start_secs; 350 assert(interval_in_seconds >= 0.0, 351 "Bad interval between cms collections"); 352 353 // Sample for performance counter 354 avg_concurrent_interval()->sample(interval_in_seconds); 355 356 // STW costs (initial and remark pauses) 357 // Cost of collection (unit-less) 358 assert(_latest_cms_initial_mark_start_to_end_time_secs >= 0.0, 359 "Bad initial mark pause"); 360 assert(_latest_cms_remark_start_to_end_time_secs >= 0.0, 361 "Bad remark pause"); 362 double STW_time_in_seconds = 363 _latest_cms_initial_mark_start_to_end_time_secs + 364 _latest_cms_remark_start_to_end_time_secs; 365 double STW_collection_cost = 0.0; 366 if (interval_in_seconds > 0.0) { 367 // cost for the STW phases of the concurrent collection. 368 STW_collection_cost = STW_time_in_seconds / interval_in_seconds; 369 avg_cms_STW_gc_cost()->sample(STW_collection_cost); 370 } 371 if (PrintAdaptiveSizePolicy && Verbose) { 372 gclog_or_tty->print("cmsAdaptiveSizePolicy::STW_collection_end: " 373 "STW gc cost: %f average: %f", STW_collection_cost, 374 avg_cms_STW_gc_cost()->average()); 375 gclog_or_tty->print_cr(" STW pause: %f (ms) STW period %f (ms)", 376 (double) STW_time_in_seconds * MILLIUNITS, 377 (double) interval_in_seconds * MILLIUNITS); 378 } 379 380 double concurrent_cost = 0.0; 381 if (latest_cms_sum_concurrent_phases_time_secs > 0.0) { 382 concurrent_cost = concurrent_collection_cost(interval_in_seconds); 383 384 avg_concurrent_gc_cost()->sample(concurrent_cost); 385 // Average this ms cost into all the other types gc costs 386 387 if (PrintAdaptiveSizePolicy && Verbose) { 388 gclog_or_tty->print("cmsAdaptiveSizePolicy::concurrent_phases_end: " 389 "concurrent gc cost: %f average: %f", 390 concurrent_cost, 391 _avg_concurrent_gc_cost->average()); 392 gclog_or_tty->print_cr(" concurrent time: %f (ms) cms period %f (ms)" 393 " processor fraction: %f", 394 latest_cms_sum_concurrent_phases_time_secs * MILLIUNITS, 395 interval_in_seconds * MILLIUNITS, 396 concurrent_processor_fraction()); 397 } 398 } 399 double total_collection_cost = STW_collection_cost + concurrent_cost; 400 avg_major_gc_cost()->sample(total_collection_cost); 401 402 // Gather information for estimating future behavior 403 double initial_pause_in_ms = _latest_cms_initial_mark_start_to_end_time_secs * MILLIUNITS; 404 double remark_pause_in_ms = _latest_cms_remark_start_to_end_time_secs * MILLIUNITS; 405 406 double cur_promo_size_in_mbytes = ((double)cur_promo)/((double)M); 407 initial_pause_old_estimator()->update(cur_promo_size_in_mbytes, 408 initial_pause_in_ms); 409 remark_pause_old_estimator()->update(cur_promo_size_in_mbytes, 410 remark_pause_in_ms); 411 major_collection_estimator()->update(cur_promo_size_in_mbytes, 412 total_collection_cost); 413 414 // This estimate uses the average eden size. It could also 415 // have used the latest eden size. Which is better? 416 double cur_eden_size_in_mbytes = ((double)cur_eden)/((double) M); 417 initial_pause_young_estimator()->update(cur_eden_size_in_mbytes, 418 initial_pause_in_ms); 419 remark_pause_young_estimator()->update(cur_eden_size_in_mbytes, 420 remark_pause_in_ms); 421 } 422 423 clear_internal_time_intervals(); 424 425 set_first_after_collection(); 426 427 // The concurrent phases keeps track of it's own mutator interval 428 // with this timer. This allows the stop-the-world phase to 429 // be included in the mutator time so that the stop-the-world time 430 // is not double counted. Reset and start it. 431 _concurrent_timer.reset(); 432 _concurrent_timer.start(); 433 434 // The mutator time between STW phases does not include the 435 // concurrent collection time. 436 _STW_timer.reset(); 437 _STW_timer.start(); 438 } 439 440 void CMSAdaptiveSizePolicy::checkpoint_roots_initial_begin() { 441 // Update the interval time 442 _STW_timer.stop(); 443 _latest_cms_reset_end_to_initial_mark_start_secs = _STW_timer.seconds(); 444 // Reset for the initial mark 445 _STW_timer.reset(); 446 _STW_timer.start(); 447 } 448 449 void CMSAdaptiveSizePolicy::checkpoint_roots_initial_end( 450 GCCause::Cause gc_cause) { 451 _STW_timer.stop(); 452 453 if (gc_cause != GCCause::_java_lang_system_gc || 454 UseAdaptiveSizePolicyWithSystemGC) { 455 _latest_cms_initial_mark_start_to_end_time_secs = _STW_timer.seconds(); 456 avg_initial_pause()->sample(_latest_cms_initial_mark_start_to_end_time_secs); 457 458 if (PrintAdaptiveSizePolicy && Verbose) { 459 gclog_or_tty->print( 460 "cmsAdaptiveSizePolicy::checkpoint_roots_initial_end: " 461 "initial pause: %f ", _latest_cms_initial_mark_start_to_end_time_secs); 462 } 463 } 464 465 _STW_timer.reset(); 466 _STW_timer.start(); 467 } 468 469 void CMSAdaptiveSizePolicy::checkpoint_roots_final_begin() { 470 _STW_timer.stop(); 471 _latest_cms_initial_mark_end_to_remark_start_secs = _STW_timer.seconds(); 472 // Start accumulating time for the remark in the STW timer. 473 _STW_timer.reset(); 474 _STW_timer.start(); 475 } 476 477 void CMSAdaptiveSizePolicy::checkpoint_roots_final_end( 478 GCCause::Cause gc_cause) { 479 _STW_timer.stop(); 480 if (gc_cause != GCCause::_java_lang_system_gc || 481 UseAdaptiveSizePolicyWithSystemGC) { 482 // Total initial mark pause + remark pause. 483 _latest_cms_remark_start_to_end_time_secs = _STW_timer.seconds(); 484 double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + 485 _latest_cms_remark_start_to_end_time_secs; 486 double STW_time_in_ms = STW_time_in_seconds * MILLIUNITS; 487 488 avg_remark_pause()->sample(_latest_cms_remark_start_to_end_time_secs); 489 490 // Sample total for initial mark + remark 491 avg_cms_STW_time()->sample(STW_time_in_seconds); 492 493 if (PrintAdaptiveSizePolicy && Verbose) { 494 gclog_or_tty->print("cmsAdaptiveSizePolicy::checkpoint_roots_final_end: " 495 "remark pause: %f", _latest_cms_remark_start_to_end_time_secs); 496 } 497 498 } 499 // Don't start the STW times here because the concurrent 500 // sweep and reset has not happened. 501 // Keep the old comment above in case I don't understand 502 // what is going on but now 503 // Start the STW timer because it is used by ms_collection_begin() 504 // and ms_collection_end() to get the sweep time if a MS is being 505 // done in the foreground. 506 _STW_timer.reset(); 507 _STW_timer.start(); 508 } 509 510 void CMSAdaptiveSizePolicy::msc_collection_begin() { 511 if (PrintAdaptiveSizePolicy && Verbose) { 512 gclog_or_tty->print(" "); 513 gclog_or_tty->stamp(); 514 gclog_or_tty->print(": msc_collection_begin "); 515 } 516 _STW_timer.stop(); 517 _latest_cms_msc_end_to_msc_start_time_secs = _STW_timer.seconds(); 518 if (PrintAdaptiveSizePolicy && Verbose) { 519 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::msc_collection_begin: " 520 "mutator time %f", 521 _latest_cms_msc_end_to_msc_start_time_secs); 522 } 523 avg_msc_interval()->sample(_latest_cms_msc_end_to_msc_start_time_secs); 524 _STW_timer.reset(); 525 _STW_timer.start(); 526 } 527 528 void CMSAdaptiveSizePolicy::msc_collection_end(GCCause::Cause gc_cause) { 529 if (PrintAdaptiveSizePolicy && Verbose) { 530 gclog_or_tty->print(" "); 531 gclog_or_tty->stamp(); 532 gclog_or_tty->print(": msc_collection_end "); 533 } 534 _STW_timer.stop(); 535 if (gc_cause != GCCause::_java_lang_system_gc || 536 UseAdaptiveSizePolicyWithSystemGC) { 537 double msc_pause_in_seconds = _STW_timer.seconds(); 538 if ((_latest_cms_msc_end_to_msc_start_time_secs > 0.0) && 539 (msc_pause_in_seconds > 0.0)) { 540 avg_msc_pause()->sample(msc_pause_in_seconds); 541 double mutator_time_in_seconds = 0.0; 542 if (_latest_cms_collection_end_to_collection_start_secs == 0.0) { 543 // This assertion may fail because of time stamp granularity. 544 // Comment it out and investigate it at a later time. The large 545 // time stamp granularity occurs on some older linux systems. 546 #ifndef CLOCK_GRANULARITY_TOO_LARGE 547 assert((_latest_cms_concurrent_marking_time_secs == 0.0) && 548 (_latest_cms_concurrent_precleaning_time_secs == 0.0) && 549 (_latest_cms_concurrent_sweeping_time_secs == 0.0), 550 "There should not be any concurrent time"); 551 #endif 552 // A concurrent collection did not start. Mutator time 553 // between collections comes from the STW MSC timer. 554 mutator_time_in_seconds = _latest_cms_msc_end_to_msc_start_time_secs; 555 } else { 556 // The concurrent collection did start so count the mutator 557 // time to the start of the concurrent collection. In this 558 // case the _latest_cms_msc_end_to_msc_start_time_secs measures 559 // the time between the initial mark or remark and the 560 // start of the MSC. That has no real meaning. 561 mutator_time_in_seconds = _latest_cms_collection_end_to_collection_start_secs; 562 } 563 564 double latest_cms_sum_concurrent_phases_time_secs = 565 concurrent_collection_time(); 566 double interval_in_seconds = 567 mutator_time_in_seconds + 568 _latest_cms_initial_mark_start_to_end_time_secs + 569 _latest_cms_remark_start_to_end_time_secs + 570 latest_cms_sum_concurrent_phases_time_secs + 571 msc_pause_in_seconds; 572 573 if (PrintAdaptiveSizePolicy && Verbose) { 574 gclog_or_tty->print_cr(" interval_in_seconds %f \n" 575 " mutator_time_in_seconds %f \n" 576 " _latest_cms_initial_mark_start_to_end_time_secs %f\n" 577 " _latest_cms_remark_start_to_end_time_secs %f\n" 578 " latest_cms_sum_concurrent_phases_time_secs %f\n" 579 " msc_pause_in_seconds %f\n", 580 interval_in_seconds, 581 mutator_time_in_seconds, 582 _latest_cms_initial_mark_start_to_end_time_secs, 583 _latest_cms_remark_start_to_end_time_secs, 584 latest_cms_sum_concurrent_phases_time_secs, 585 msc_pause_in_seconds); 586 } 587 588 // The concurrent cost is wasted cost but it should be 589 // included. 590 double concurrent_cost = concurrent_collection_cost(interval_in_seconds); 591 592 // Initial mark and remark, also wasted. 593 double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + 594 _latest_cms_remark_start_to_end_time_secs; 595 double STW_collection_cost = 596 collection_cost(STW_time_in_seconds, interval_in_seconds) + 597 concurrent_cost; 598 599 if (PrintAdaptiveSizePolicy && Verbose) { 600 gclog_or_tty->print_cr(" msc_collection_end:\n" 601 "_latest_cms_collection_end_to_collection_start_secs %f\n" 602 "_latest_cms_msc_end_to_msc_start_time_secs %f\n" 603 "_latest_cms_initial_mark_start_to_end_time_secs %f\n" 604 "_latest_cms_remark_start_to_end_time_secs %f\n" 605 "latest_cms_sum_concurrent_phases_time_secs %f\n", 606 _latest_cms_collection_end_to_collection_start_secs, 607 _latest_cms_msc_end_to_msc_start_time_secs, 608 _latest_cms_initial_mark_start_to_end_time_secs, 609 _latest_cms_remark_start_to_end_time_secs, 610 latest_cms_sum_concurrent_phases_time_secs); 611 612 gclog_or_tty->print_cr(" msc_collection_end: \n" 613 "latest_cms_sum_concurrent_phases_time_secs %f\n" 614 "STW_time_in_seconds %f\n" 615 "msc_pause_in_seconds %f\n", 616 latest_cms_sum_concurrent_phases_time_secs, 617 STW_time_in_seconds, 618 msc_pause_in_seconds); 619 } 620 621 double cost = concurrent_cost + STW_collection_cost + 622 collection_cost(msc_pause_in_seconds, interval_in_seconds); 623 624 _avg_msc_gc_cost->sample(cost); 625 626 // Average this ms cost into all the other types gc costs 627 avg_major_gc_cost()->sample(cost); 628 629 // Sample for performance counter 630 _avg_msc_interval->sample(interval_in_seconds); 631 if (PrintAdaptiveSizePolicy && Verbose) { 632 gclog_or_tty->print("cmsAdaptiveSizePolicy::msc_collection_end: " 633 "MSC gc cost: %f average: %f", cost, 634 _avg_msc_gc_cost->average()); 635 636 double msc_pause_in_ms = msc_pause_in_seconds * MILLIUNITS; 637 gclog_or_tty->print_cr(" MSC pause: %f (ms) MSC period %f (ms)", 638 msc_pause_in_ms, (double) interval_in_seconds * MILLIUNITS); 639 } 640 } 641 } 642 643 clear_internal_time_intervals(); 644 645 // Can this call be put into the epilogue? 646 set_first_after_collection(); 647 648 // The concurrent phases keeps track of it's own mutator interval 649 // with this timer. This allows the stop-the-world phase to 650 // be included in the mutator time so that the stop-the-world time 651 // is not double counted. Reset and start it. 652 _concurrent_timer.stop(); 653 _concurrent_timer.reset(); 654 _concurrent_timer.start(); 655 656 _STW_timer.reset(); 657 _STW_timer.start(); 658 } 659 660 void CMSAdaptiveSizePolicy::ms_collection_begin() { 661 if (PrintAdaptiveSizePolicy && Verbose) { 662 gclog_or_tty->print(" "); 663 gclog_or_tty->stamp(); 664 gclog_or_tty->print(": ms_collection_begin "); 665 } 666 _STW_timer.stop(); 667 _latest_cms_ms_end_to_ms_start = _STW_timer.seconds(); 668 if (PrintAdaptiveSizePolicy && Verbose) { 669 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::ms_collection_begin: " 670 "mutator time %f", 671 _latest_cms_ms_end_to_ms_start); 672 } 673 avg_ms_interval()->sample(_STW_timer.seconds()); 674 _STW_timer.reset(); 675 _STW_timer.start(); 676 } 677 678 void CMSAdaptiveSizePolicy::ms_collection_end(GCCause::Cause gc_cause) { 679 if (PrintAdaptiveSizePolicy && Verbose) { 680 gclog_or_tty->print(" "); 681 gclog_or_tty->stamp(); 682 gclog_or_tty->print(": ms_collection_end "); 683 } 684 _STW_timer.stop(); 685 if (gc_cause != GCCause::_java_lang_system_gc || 686 UseAdaptiveSizePolicyWithSystemGC) { 687 // The MS collection is a foreground collection that does all 688 // the parts of a mostly concurrent collection. 689 // 690 // For this collection include the cost of the 691 // initial mark 692 // remark 693 // all concurrent time (scaled down by the 694 // concurrent_processor_fraction). Some 695 // may be zero if the baton was passed before 696 // it was reached. 697 // concurrent marking 698 // sweeping 699 // resetting 700 // STW after baton was passed (STW_in_foreground_in_seconds) 701 double STW_in_foreground_in_seconds = _STW_timer.seconds(); 702 703 double latest_cms_sum_concurrent_phases_time_secs = 704 concurrent_collection_time(); 705 if (PrintAdaptiveSizePolicy && Verbose) { 706 gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::ms_collection_end " 707 "STW_in_foreground_in_seconds %f " 708 "_latest_cms_initial_mark_start_to_end_time_secs %f " 709 "_latest_cms_remark_start_to_end_time_secs %f " 710 "latest_cms_sum_concurrent_phases_time_secs %f " 711 "_latest_cms_ms_marking_start_to_end_time_secs %f " 712 "_latest_cms_ms_end_to_ms_start %f", 713 STW_in_foreground_in_seconds, 714 _latest_cms_initial_mark_start_to_end_time_secs, 715 _latest_cms_remark_start_to_end_time_secs, 716 latest_cms_sum_concurrent_phases_time_secs, 717 _latest_cms_ms_marking_start_to_end_time_secs, 718 _latest_cms_ms_end_to_ms_start); 719 } 720 721 double STW_marking_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + 722 _latest_cms_remark_start_to_end_time_secs; 723 #ifndef CLOCK_GRANULARITY_TOO_LARGE 724 assert(_latest_cms_ms_marking_start_to_end_time_secs == 0.0 || 725 latest_cms_sum_concurrent_phases_time_secs == 0.0, 726 "marking done twice?"); 727 #endif 728 double ms_time_in_seconds = STW_marking_in_seconds + 729 STW_in_foreground_in_seconds + 730 _latest_cms_ms_marking_start_to_end_time_secs + 731 scaled_concurrent_collection_time(); 732 avg_ms_pause()->sample(ms_time_in_seconds); 733 // Use the STW costs from the initial mark and remark plus 734 // the cost of the concurrent phase to calculate a 735 // collection cost. 736 double cost = 0.0; 737 if ((_latest_cms_ms_end_to_ms_start > 0.0) && 738 (ms_time_in_seconds > 0.0)) { 739 double interval_in_seconds = 740 _latest_cms_ms_end_to_ms_start + ms_time_in_seconds; 741 742 if (PrintAdaptiveSizePolicy && Verbose) { 743 gclog_or_tty->print_cr("\n ms_time_in_seconds %f " 744 "latest_cms_sum_concurrent_phases_time_secs %f " 745 "interval_in_seconds %f", 746 ms_time_in_seconds, 747 latest_cms_sum_concurrent_phases_time_secs, 748 interval_in_seconds); 749 } 750 751 cost = collection_cost(ms_time_in_seconds, interval_in_seconds); 752 753 _avg_ms_gc_cost->sample(cost); 754 // Average this ms cost into all the other types gc costs 755 avg_major_gc_cost()->sample(cost); 756 757 // Sample for performance counter 758 _avg_ms_interval->sample(interval_in_seconds); 759 } 760 if (PrintAdaptiveSizePolicy && Verbose) { 761 gclog_or_tty->print("cmsAdaptiveSizePolicy::ms_collection_end: " 762 "MS gc cost: %f average: %f", cost, _avg_ms_gc_cost->average()); 763 764 double ms_time_in_ms = ms_time_in_seconds * MILLIUNITS; 765 gclog_or_tty->print_cr(" MS pause: %f (ms) MS period %f (ms)", 766 ms_time_in_ms, 767 _latest_cms_ms_end_to_ms_start * MILLIUNITS); 768 } 769 } 770 771 // Consider putting this code (here to end) into a 772 // method for convenience. 773 clear_internal_time_intervals(); 774 775 set_first_after_collection(); 776 777 // The concurrent phases keeps track of it's own mutator interval 778 // with this timer. This allows the stop-the-world phase to 779 // be included in the mutator time so that the stop-the-world time 780 // is not double counted. Reset and start it. 781 _concurrent_timer.stop(); 782 _concurrent_timer.reset(); 783 _concurrent_timer.start(); 784 785 _STW_timer.reset(); 786 _STW_timer.start(); 787 } 788 789 void CMSAdaptiveSizePolicy::clear_internal_time_intervals() { 790 _latest_cms_reset_end_to_initial_mark_start_secs = 0.0; 791 _latest_cms_initial_mark_end_to_remark_start_secs = 0.0; 792 _latest_cms_collection_end_to_collection_start_secs = 0.0; 793 _latest_cms_concurrent_marking_time_secs = 0.0; 794 _latest_cms_concurrent_precleaning_time_secs = 0.0; 795 _latest_cms_concurrent_sweeping_time_secs = 0.0; 796 _latest_cms_msc_end_to_msc_start_time_secs = 0.0; 797 _latest_cms_ms_end_to_ms_start = 0.0; 798 _latest_cms_remark_start_to_end_time_secs = 0.0; 799 _latest_cms_initial_mark_start_to_end_time_secs = 0.0; 800 _latest_cms_ms_marking_start_to_end_time_secs = 0.0; 801 } 802 803 void CMSAdaptiveSizePolicy::clear_generation_free_space_flags() { 804 AdaptiveSizePolicy::clear_generation_free_space_flags(); 805 806 set_change_young_gen_for_maj_pauses(0); 807 } 808 809 void CMSAdaptiveSizePolicy::concurrent_phases_resume() { 810 if (PrintAdaptiveSizePolicy && Verbose) { 811 gclog_or_tty->stamp(); 812 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_phases_resume()"); 813 } 814 _concurrent_timer.start(); 815 } 816 817 double CMSAdaptiveSizePolicy::time_since_major_gc() const { 818 _concurrent_timer.stop(); 819 double time_since_cms_gc = _concurrent_timer.seconds(); 820 _concurrent_timer.start(); 821 _STW_timer.stop(); 822 double time_since_STW_gc = _STW_timer.seconds(); 823 _STW_timer.start(); 824 825 return MIN2(time_since_cms_gc, time_since_STW_gc); 826 } 827 828 double CMSAdaptiveSizePolicy::major_gc_interval_average_for_decay() const { 829 double cms_interval = _avg_concurrent_interval->average(); 830 double msc_interval = _avg_msc_interval->average(); 831 double ms_interval = _avg_ms_interval->average(); 832 833 return MAX3(cms_interval, msc_interval, ms_interval); 834 } 835 836 double CMSAdaptiveSizePolicy::cms_gc_cost() const { 837 return avg_major_gc_cost()->average(); 838 } 839 840 void CMSAdaptiveSizePolicy::ms_collection_marking_begin() { 841 _STW_timer.stop(); 842 // Start accumulating time for the marking in the STW timer. 843 _STW_timer.reset(); 844 _STW_timer.start(); 845 } 846 847 void CMSAdaptiveSizePolicy::ms_collection_marking_end( 848 GCCause::Cause gc_cause) { 849 _STW_timer.stop(); 850 if (gc_cause != GCCause::_java_lang_system_gc || 851 UseAdaptiveSizePolicyWithSystemGC) { 852 _latest_cms_ms_marking_start_to_end_time_secs = _STW_timer.seconds(); 853 if (PrintAdaptiveSizePolicy && Verbose) { 854 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::" 855 "msc_collection_marking_end: mutator time %f", 856 _latest_cms_ms_marking_start_to_end_time_secs); 857 } 858 } 859 _STW_timer.reset(); 860 _STW_timer.start(); 861 } 862 863 double CMSAdaptiveSizePolicy::gc_cost() const { 864 double cms_gen_cost = cms_gc_cost(); 865 double result = MIN2(1.0, minor_gc_cost() + cms_gen_cost); 866 assert(result >= 0.0, "Both minor and major costs are non-negative"); 867 return result; 868 } 869 870 // Cost of collection (unit-less) 871 double CMSAdaptiveSizePolicy::collection_cost(double pause_in_seconds, 872 double interval_in_seconds) { 873 // Cost of collection (unit-less) 874 double cost = 0.0; 875 if ((interval_in_seconds > 0.0) && 876 (pause_in_seconds > 0.0)) { 877 cost = 878 pause_in_seconds / interval_in_seconds; 879 } 880 return cost; 881 } 882 883 size_t CMSAdaptiveSizePolicy::adjust_eden_for_pause_time(size_t cur_eden) { 884 size_t change = 0; 885 size_t desired_eden = cur_eden; 886 887 // reduce eden size 888 change = eden_decrement_aligned_down(cur_eden); 889 desired_eden = cur_eden - change; 890 891 if (PrintAdaptiveSizePolicy && Verbose) { 892 gclog_or_tty->print_cr( 893 "CMSAdaptiveSizePolicy::adjust_eden_for_pause_time " 894 "adjusting eden for pause time. " 895 " starting eden size " SIZE_FORMAT 896 " reduced eden size " SIZE_FORMAT 897 " eden delta " SIZE_FORMAT, 898 cur_eden, desired_eden, change); 899 } 900 901 return desired_eden; 902 } 903 904 size_t CMSAdaptiveSizePolicy::adjust_eden_for_throughput(size_t cur_eden) { 905 906 size_t desired_eden = cur_eden; 907 908 set_change_young_gen_for_throughput(increase_young_gen_for_througput_true); 909 910 size_t change = eden_increment_aligned_up(cur_eden); 911 size_t scaled_change = scale_by_gen_gc_cost(change, minor_gc_cost()); 912 913 if (cur_eden + scaled_change > cur_eden) { 914 desired_eden = cur_eden + scaled_change; 915 } 916 917 _young_gen_change_for_minor_throughput++; 918 919 if (PrintAdaptiveSizePolicy && Verbose) { 920 gclog_or_tty->print_cr( 921 "CMSAdaptiveSizePolicy::adjust_eden_for_throughput " 922 "adjusting eden for throughput. " 923 " starting eden size " SIZE_FORMAT 924 " increased eden size " SIZE_FORMAT 925 " eden delta " SIZE_FORMAT, 926 cur_eden, desired_eden, scaled_change); 927 } 928 929 return desired_eden; 930 } 931 932 size_t CMSAdaptiveSizePolicy::adjust_eden_for_footprint(size_t cur_eden) { 933 934 set_decrease_for_footprint(decrease_young_gen_for_footprint_true); 935 936 size_t change = eden_decrement(cur_eden); 937 size_t desired_eden_size = cur_eden - change; 938 939 if (PrintAdaptiveSizePolicy && Verbose) { 940 gclog_or_tty->print_cr( 941 "CMSAdaptiveSizePolicy::adjust_eden_for_footprint " 942 "adjusting eden for footprint. " 943 " starting eden size " SIZE_FORMAT 944 " reduced eden size " SIZE_FORMAT 945 " eden delta " SIZE_FORMAT, 946 cur_eden, desired_eden_size, change); 947 } 948 return desired_eden_size; 949 } 950 951 // The eden and promo versions should be combined if possible. 952 // They are the same except that the sizes of the decrement 953 // and increment are different for eden and promo. 954 size_t CMSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) { 955 size_t delta = eden_decrement(cur_eden); 956 return align_size_down(delta, generation_alignment()); 957 } 958 959 size_t CMSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) { 960 size_t delta = eden_increment(cur_eden); 961 return align_size_up(delta, generation_alignment()); 962 } 963 964 size_t CMSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) { 965 size_t delta = promo_decrement(cur_promo); 966 return align_size_down(delta, generation_alignment()); 967 } 968 969 size_t CMSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) { 970 size_t delta = promo_increment(cur_promo); 971 return align_size_up(delta, generation_alignment()); 972 } 973 974 975 void CMSAdaptiveSizePolicy::compute_eden_space_size(size_t cur_eden, 976 size_t max_eden_size) 977 { 978 size_t desired_eden_size = cur_eden; 979 size_t eden_limit = max_eden_size; 980 981 // Printout input 982 if (PrintGC && PrintAdaptiveSizePolicy) { 983 gclog_or_tty->print_cr( 984 "CMSAdaptiveSizePolicy::compute_eden_space_size: " 985 "cur_eden " SIZE_FORMAT, 986 cur_eden); 987 } 988 989 // Used for diagnostics 990 clear_generation_free_space_flags(); 991 992 if (_avg_minor_pause->padded_average() > gc_pause_goal_sec()) { 993 if (minor_pause_young_estimator()->decrement_will_decrease()) { 994 // If the minor pause is too long, shrink the young gen. 995 set_change_young_gen_for_min_pauses( 996 decrease_young_gen_for_min_pauses_true); 997 desired_eden_size = adjust_eden_for_pause_time(desired_eden_size); 998 } 999 } else if ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) || 1000 (avg_initial_pause()->padded_average() > gc_pause_goal_sec())) { 1001 // The remark or initial pauses are not meeting the goal. Should 1002 // the generation be shrunk? 1003 if (get_and_clear_first_after_collection() && 1004 ((avg_remark_pause()->padded_average() > gc_pause_goal_sec() && 1005 remark_pause_young_estimator()->decrement_will_decrease()) || 1006 (avg_initial_pause()->padded_average() > gc_pause_goal_sec() && 1007 initial_pause_young_estimator()->decrement_will_decrease()))) { 1008 1009 set_change_young_gen_for_maj_pauses( 1010 decrease_young_gen_for_maj_pauses_true); 1011 1012 // If the remark or initial pause is too long and this is the 1013 // first young gen collection after a cms collection, shrink 1014 // the young gen. 1015 desired_eden_size = adjust_eden_for_pause_time(desired_eden_size); 1016 } 1017 // If not the first young gen collection after a cms collection, 1018 // don't do anything. In this case an adjustment has already 1019 // been made and the results of the adjustment has not yet been 1020 // measured. 1021 } else if ((minor_gc_cost() >= 0.0) && 1022 (adjusted_mutator_cost() < _throughput_goal)) { 1023 desired_eden_size = adjust_eden_for_throughput(desired_eden_size); 1024 } else { 1025 desired_eden_size = adjust_eden_for_footprint(desired_eden_size); 1026 } 1027 1028 if (PrintGC && PrintAdaptiveSizePolicy) { 1029 gclog_or_tty->print_cr( 1030 "CMSAdaptiveSizePolicy::compute_eden_space_size limits:" 1031 " desired_eden_size: " SIZE_FORMAT 1032 " old_eden_size: " SIZE_FORMAT, 1033 desired_eden_size, cur_eden); 1034 } 1035 1036 set_eden_size(desired_eden_size); 1037 } 1038 1039 size_t CMSAdaptiveSizePolicy::adjust_promo_for_pause_time(size_t cur_promo) { 1040 size_t change = 0; 1041 size_t desired_promo = cur_promo; 1042 // Move this test up to caller like the adjust_eden_for_pause_time() 1043 // call. 1044 if ((AdaptiveSizePausePolicy == 0) && 1045 ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) || 1046 (avg_initial_pause()->padded_average() > gc_pause_goal_sec()))) { 1047 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true); 1048 change = promo_decrement_aligned_down(cur_promo); 1049 desired_promo = cur_promo - change; 1050 } else if ((AdaptiveSizePausePolicy > 0) && 1051 (((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) && 1052 remark_pause_old_estimator()->decrement_will_decrease()) || 1053 ((avg_initial_pause()->padded_average() > gc_pause_goal_sec()) && 1054 initial_pause_old_estimator()->decrement_will_decrease()))) { 1055 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true); 1056 change = promo_decrement_aligned_down(cur_promo); 1057 desired_promo = cur_promo - change; 1058 } 1059 1060 if ((change != 0) &&PrintAdaptiveSizePolicy && Verbose) { 1061 gclog_or_tty->print_cr( 1062 "CMSAdaptiveSizePolicy::adjust_promo_for_pause_time " 1063 "adjusting promo for pause time. " 1064 " starting promo size " SIZE_FORMAT 1065 " reduced promo size " SIZE_FORMAT 1066 " promo delta " SIZE_FORMAT, 1067 cur_promo, desired_promo, change); 1068 } 1069 1070 return desired_promo; 1071 } 1072 1073 // Try to share this with PS. 1074 size_t CMSAdaptiveSizePolicy::scale_by_gen_gc_cost(size_t base_change, 1075 double gen_gc_cost) { 1076 1077 // Calculate the change to use for the tenured gen. 1078 size_t scaled_change = 0; 1079 // Can the increment to the generation be scaled? 1080 if (gc_cost() >= 0.0 && gen_gc_cost >= 0.0) { 1081 double scale_by_ratio = gen_gc_cost / gc_cost(); 1082 scaled_change = 1083 (size_t) (scale_by_ratio * (double) base_change); 1084 if (PrintAdaptiveSizePolicy && Verbose) { 1085 gclog_or_tty->print_cr( 1086 "Scaled tenured increment: " SIZE_FORMAT " by %f down to " 1087 SIZE_FORMAT, 1088 base_change, scale_by_ratio, scaled_change); 1089 } 1090 } else if (gen_gc_cost >= 0.0) { 1091 // Scaling is not going to work. If the major gc time is the 1092 // larger than the other GC costs, give it a full increment. 1093 if (gen_gc_cost >= (gc_cost() - gen_gc_cost)) { 1094 scaled_change = base_change; 1095 } 1096 } else { 1097 // Don't expect to get here but it's ok if it does 1098 // in the product build since the delta will be 0 1099 // and nothing will change. 1100 assert(false, "Unexpected value for gc costs"); 1101 } 1102 1103 return scaled_change; 1104 } 1105 1106 size_t CMSAdaptiveSizePolicy::adjust_promo_for_throughput(size_t cur_promo) { 1107 1108 size_t desired_promo = cur_promo; 1109 1110 set_change_old_gen_for_throughput(increase_old_gen_for_throughput_true); 1111 1112 size_t change = promo_increment_aligned_up(cur_promo); 1113 size_t scaled_change = scale_by_gen_gc_cost(change, major_gc_cost()); 1114 1115 if (cur_promo + scaled_change > cur_promo) { 1116 desired_promo = cur_promo + scaled_change; 1117 } 1118 1119 _old_gen_change_for_major_throughput++; 1120 1121 if (PrintAdaptiveSizePolicy && Verbose) { 1122 gclog_or_tty->print_cr( 1123 "CMSAdaptiveSizePolicy::adjust_promo_for_throughput " 1124 "adjusting promo for throughput. " 1125 " starting promo size " SIZE_FORMAT 1126 " increased promo size " SIZE_FORMAT 1127 " promo delta " SIZE_FORMAT, 1128 cur_promo, desired_promo, scaled_change); 1129 } 1130 1131 return desired_promo; 1132 } 1133 1134 size_t CMSAdaptiveSizePolicy::adjust_promo_for_footprint(size_t cur_promo, 1135 size_t cur_eden) { 1136 1137 set_decrease_for_footprint(decrease_young_gen_for_footprint_true); 1138 1139 size_t change = promo_decrement(cur_promo); 1140 size_t desired_promo_size = cur_promo - change; 1141 1142 if (PrintAdaptiveSizePolicy && Verbose) { 1143 gclog_or_tty->print_cr( 1144 "CMSAdaptiveSizePolicy::adjust_promo_for_footprint " 1145 "adjusting promo for footprint. " 1146 " starting promo size " SIZE_FORMAT 1147 " reduced promo size " SIZE_FORMAT 1148 " promo delta " SIZE_FORMAT, 1149 cur_promo, desired_promo_size, change); 1150 } 1151 return desired_promo_size; 1152 } 1153 1154 void CMSAdaptiveSizePolicy::compute_tenured_generation_free_space( 1155 size_t cur_tenured_free, 1156 size_t max_tenured_available, 1157 size_t cur_eden) { 1158 // This can be bad if the desired value grows/shrinks without 1159 // any connection to the read free space 1160 size_t desired_promo_size = promo_size(); 1161 size_t tenured_limit = max_tenured_available; 1162 1163 // Printout input 1164 if (PrintGC && PrintAdaptiveSizePolicy) { 1165 gclog_or_tty->print_cr( 1166 "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space: " 1167 "cur_tenured_free " SIZE_FORMAT 1168 " max_tenured_available " SIZE_FORMAT, 1169 cur_tenured_free, max_tenured_available); 1170 } 1171 1172 // Used for diagnostics 1173 clear_generation_free_space_flags(); 1174 1175 set_decide_at_full_gc(decide_at_full_gc_true); 1176 if (avg_remark_pause()->padded_average() > gc_pause_goal_sec() || 1177 avg_initial_pause()->padded_average() > gc_pause_goal_sec()) { 1178 desired_promo_size = adjust_promo_for_pause_time(cur_tenured_free); 1179 } else if (avg_minor_pause()->padded_average() > gc_pause_goal_sec()) { 1180 // Nothing to do since the minor collections are too large and 1181 // this method only deals with the cms generation. 1182 } else if ((cms_gc_cost() >= 0.0) && 1183 (adjusted_mutator_cost() < _throughput_goal)) { 1184 desired_promo_size = adjust_promo_for_throughput(cur_tenured_free); 1185 } else { 1186 desired_promo_size = adjust_promo_for_footprint(cur_tenured_free, 1187 cur_eden); 1188 } 1189 1190 if (PrintGC && PrintAdaptiveSizePolicy) { 1191 gclog_or_tty->print_cr( 1192 "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space limits:" 1193 " desired_promo_size: " SIZE_FORMAT 1194 " old_promo_size: " SIZE_FORMAT, 1195 desired_promo_size, cur_tenured_free); 1196 } 1197 1198 set_promo_size(desired_promo_size); 1199 } 1200 1201 uint CMSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold( 1202 bool is_survivor_overflow, 1203 uint tenuring_threshold, 1204 size_t survivor_limit) { 1205 assert(survivor_limit >= generation_alignment(), 1206 "survivor_limit too small"); 1207 assert((size_t)align_size_down(survivor_limit, generation_alignment()) 1208 == survivor_limit, "survivor_limit not aligned"); 1209 1210 // Change UsePSAdaptiveSurvivorSizePolicy -> UseAdaptiveSurvivorSizePolicy? 1211 if (!UsePSAdaptiveSurvivorSizePolicy || 1212 !young_gen_policy_is_ready()) { 1213 return tenuring_threshold; 1214 } 1215 1216 // We'll decide whether to increase or decrease the tenuring 1217 // threshold based partly on the newly computed survivor size 1218 // (if we hit the maximum limit allowed, we'll always choose to 1219 // decrement the threshold). 1220 bool incr_tenuring_threshold = false; 1221 bool decr_tenuring_threshold = false; 1222 1223 set_decrement_tenuring_threshold_for_gc_cost(false); 1224 set_increment_tenuring_threshold_for_gc_cost(false); 1225 set_decrement_tenuring_threshold_for_survivor_limit(false); 1226 1227 if (!is_survivor_overflow) { 1228 // Keep running averages on how much survived 1229 1230 // We use the tenuring threshold to equalize the cost of major 1231 // and minor collections. 1232 // ThresholdTolerance is used to indicate how sensitive the 1233 // tenuring threshold is to differences in cost between the 1234 // collection types. 1235 1236 // Get the times of interest. This involves a little work, so 1237 // we cache the values here. 1238 const double major_cost = major_gc_cost(); 1239 const double minor_cost = minor_gc_cost(); 1240 1241 if (minor_cost > major_cost * _threshold_tolerance_percent) { 1242 // Minor times are getting too long; lower the threshold so 1243 // less survives and more is promoted. 1244 decr_tenuring_threshold = true; 1245 set_decrement_tenuring_threshold_for_gc_cost(true); 1246 } else if (major_cost > minor_cost * _threshold_tolerance_percent) { 1247 // Major times are too long, so we want less promotion. 1248 incr_tenuring_threshold = true; 1249 set_increment_tenuring_threshold_for_gc_cost(true); 1250 } 1251 1252 } else { 1253 // Survivor space overflow occurred, so promoted and survived are 1254 // not accurate. We'll make our best guess by combining survived 1255 // and promoted and count them as survivors. 1256 // 1257 // We'll lower the tenuring threshold to see if we can correct 1258 // things. Also, set the survivor size conservatively. We're 1259 // trying to avoid many overflows from occurring if defnew size 1260 // is just too small. 1261 1262 decr_tenuring_threshold = true; 1263 } 1264 1265 // The padded average also maintains a deviation from the average; 1266 // we use this to see how good of an estimate we have of what survived. 1267 // We're trying to pad the survivor size as little as possible without 1268 // overflowing the survivor spaces. 1269 size_t target_size = align_size_up((size_t)_avg_survived->padded_average(), 1270 generation_alignment()); 1271 target_size = MAX2(target_size, generation_alignment()); 1272 1273 if (target_size > survivor_limit) { 1274 // Target size is bigger than we can handle. Let's also reduce 1275 // the tenuring threshold. 1276 target_size = survivor_limit; 1277 decr_tenuring_threshold = true; 1278 set_decrement_tenuring_threshold_for_survivor_limit(true); 1279 } 1280 1281 // Finally, increment or decrement the tenuring threshold, as decided above. 1282 // We test for decrementing first, as we might have hit the target size 1283 // limit. 1284 if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { 1285 if (tenuring_threshold > 1) { 1286 tenuring_threshold--; 1287 } 1288 } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { 1289 if (tenuring_threshold < MaxTenuringThreshold) { 1290 tenuring_threshold++; 1291 } 1292 } 1293 1294 // We keep a running average of the amount promoted which is used 1295 // to decide when we should collect the old generation (when 1296 // the amount of old gen free space is less than what we expect to 1297 // promote). 1298 1299 if (PrintAdaptiveSizePolicy) { 1300 // A little more detail if Verbose is on 1301 GenCollectedHeap* gch = GenCollectedHeap::heap(); 1302 if (Verbose) { 1303 gclog_or_tty->print( " avg_survived: %f" 1304 " avg_deviation: %f", 1305 _avg_survived->average(), 1306 _avg_survived->deviation()); 1307 } 1308 1309 gclog_or_tty->print( " avg_survived_padded_avg: %f", 1310 _avg_survived->padded_average()); 1311 1312 if (Verbose) { 1313 gclog_or_tty->print( " avg_promoted_avg: %f" 1314 " avg_promoted_dev: %f", 1315 gch->gc_stats(1)->avg_promoted()->average(), 1316 gch->gc_stats(1)->avg_promoted()->deviation()); 1317 } 1318 1319 gclog_or_tty->print( " avg_promoted_padded_avg: %f" 1320 " avg_pretenured_padded_avg: %f" 1321 " tenuring_thresh: %u" 1322 " target_size: " SIZE_FORMAT 1323 " survivor_limit: " SIZE_FORMAT, 1324 gch->gc_stats(1)->avg_promoted()->padded_average(), 1325 _avg_pretenured->padded_average(), 1326 tenuring_threshold, target_size, survivor_limit); 1327 gclog_or_tty->cr(); 1328 } 1329 1330 set_survivor_size(target_size); 1331 1332 return tenuring_threshold; 1333 } 1334 1335 bool CMSAdaptiveSizePolicy::get_and_clear_first_after_collection() { 1336 bool result = _first_after_collection; 1337 _first_after_collection = false; 1338 return result; 1339 } 1340 1341 bool CMSAdaptiveSizePolicy::print_adaptive_size_policy_on( 1342 outputStream* st) const { 1343 1344 if (!UseAdaptiveSizePolicy) { 1345 return false; 1346 } 1347 1348 GenCollectedHeap* gch = GenCollectedHeap::heap(); 1349 Generation* young = gch->get_gen(0); 1350 DefNewGeneration* def_new = young->as_DefNewGeneration(); 1351 return AdaptiveSizePolicy::print_adaptive_size_policy_on( 1352 st, 1353 def_new->tenuring_threshold()); 1354 }