1 /* 2 * Copyright (c) 2004, 2006, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 #include "incls/_precompiled.incl" 25 #include "incls/_cmsAdaptiveSizePolicy.cpp.incl" 26 27 elapsedTimer CMSAdaptiveSizePolicy::_concurrent_timer; 28 elapsedTimer CMSAdaptiveSizePolicy::_STW_timer; 29 30 // Defined if the granularity of the time measurements is potentially too large. 31 #define CLOCK_GRANULARITY_TOO_LARGE 32 33 CMSAdaptiveSizePolicy::CMSAdaptiveSizePolicy(size_t init_eden_size, 34 size_t init_promo_size, 35 size_t init_survivor_size, 36 double max_gc_minor_pause_sec, 37 double max_gc_pause_sec, 38 uint gc_cost_ratio) : 39 AdaptiveSizePolicy(init_eden_size, 40 init_promo_size, 41 init_survivor_size, 42 max_gc_pause_sec, 43 gc_cost_ratio) { 44 45 clear_internal_time_intervals(); 46 47 _processor_count = os::active_processor_count(); 48 49 if (CMSConcurrentMTEnabled && (ConcGCThreads > 1)) { 50 assert(_processor_count > 0, "Processor count is suspect"); 51 _concurrent_processor_count = MIN2((uint) ConcGCThreads, 52 (uint) _processor_count); 53 } else { 54 _concurrent_processor_count = 1; 55 } 56 57 _avg_concurrent_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 58 _avg_concurrent_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 59 _avg_concurrent_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 60 61 _avg_initial_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight, 62 PausePadding); 63 _avg_remark_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight, 64 PausePadding); 65 66 _avg_cms_STW_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 67 _avg_cms_STW_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 68 69 _avg_cms_free = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 70 _avg_cms_free_at_sweep = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 71 _avg_cms_promo = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 72 73 // Mark-sweep-compact 74 _avg_msc_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 75 _avg_msc_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 76 _avg_msc_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 77 78 // Mark-sweep 79 _avg_ms_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 80 _avg_ms_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 81 _avg_ms_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 82 83 // Variables that estimate pause times as a function of generation 84 // size. 85 _remark_pause_old_estimator = 86 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 87 _initial_pause_old_estimator = 88 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 89 _remark_pause_young_estimator = 90 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 91 _initial_pause_young_estimator = 92 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 93 94 // Alignment comes from that used in ReservedSpace. 95 _generation_alignment = os::vm_allocation_granularity(); 96 97 // Start the concurrent timer here so that the first 98 // concurrent_phases_begin() measures a finite mutator 99 // time. A finite mutator time is used to determine 100 // if a concurrent collection has been started. If this 101 // proves to be a problem, use some explicit flag to 102 // signal that a concurrent collection has been started. 103 _concurrent_timer.start(); 104 _STW_timer.start(); 105 } 106 107 double CMSAdaptiveSizePolicy::concurrent_processor_fraction() { 108 // For now assume no other daemon threads are taking alway 109 // cpu's from the application. 110 return ((double) _concurrent_processor_count / (double) _processor_count); 111 } 112 113 double CMSAdaptiveSizePolicy::concurrent_collection_cost( 114 double interval_in_seconds) { 115 // When the precleaning and sweeping phases use multiple 116 // threads, change one_processor_fraction to 117 // concurrent_processor_fraction(). 118 double one_processor_fraction = 1.0 / ((double) processor_count()); 119 double concurrent_cost = 120 collection_cost(_latest_cms_concurrent_marking_time_secs, 121 interval_in_seconds) * concurrent_processor_fraction() + 122 collection_cost(_latest_cms_concurrent_precleaning_time_secs, 123 interval_in_seconds) * one_processor_fraction + 124 collection_cost(_latest_cms_concurrent_sweeping_time_secs, 125 interval_in_seconds) * one_processor_fraction; 126 if (PrintAdaptiveSizePolicy && Verbose) { 127 gclog_or_tty->print_cr( 128 "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_cost(%f) " 129 "_latest_cms_concurrent_marking_cost %f " 130 "_latest_cms_concurrent_precleaning_cost %f " 131 "_latest_cms_concurrent_sweeping_cost %f " 132 "concurrent_processor_fraction %f " 133 "concurrent_cost %f ", 134 interval_in_seconds, 135 collection_cost(_latest_cms_concurrent_marking_time_secs, 136 interval_in_seconds), 137 collection_cost(_latest_cms_concurrent_precleaning_time_secs, 138 interval_in_seconds), 139 collection_cost(_latest_cms_concurrent_sweeping_time_secs, 140 interval_in_seconds), 141 concurrent_processor_fraction(), 142 concurrent_cost); 143 } 144 return concurrent_cost; 145 } 146 147 double CMSAdaptiveSizePolicy::concurrent_collection_time() { 148 double latest_cms_sum_concurrent_phases_time_secs = 149 _latest_cms_concurrent_marking_time_secs + 150 _latest_cms_concurrent_precleaning_time_secs + 151 _latest_cms_concurrent_sweeping_time_secs; 152 return latest_cms_sum_concurrent_phases_time_secs; 153 } 154 155 double CMSAdaptiveSizePolicy::scaled_concurrent_collection_time() { 156 // When the precleaning and sweeping phases use multiple 157 // threads, change one_processor_fraction to 158 // concurrent_processor_fraction(). 159 double one_processor_fraction = 1.0 / ((double) processor_count()); 160 double latest_cms_sum_concurrent_phases_time_secs = 161 _latest_cms_concurrent_marking_time_secs * concurrent_processor_fraction() + 162 _latest_cms_concurrent_precleaning_time_secs * one_processor_fraction + 163 _latest_cms_concurrent_sweeping_time_secs * one_processor_fraction ; 164 if (PrintAdaptiveSizePolicy && Verbose) { 165 gclog_or_tty->print_cr( 166 "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_time " 167 "_latest_cms_concurrent_marking_time_secs %f " 168 "_latest_cms_concurrent_precleaning_time_secs %f " 169 "_latest_cms_concurrent_sweeping_time_secs %f " 170 "concurrent_processor_fraction %f " 171 "latest_cms_sum_concurrent_phases_time_secs %f ", 172 _latest_cms_concurrent_marking_time_secs, 173 _latest_cms_concurrent_precleaning_time_secs, 174 _latest_cms_concurrent_sweeping_time_secs, 175 concurrent_processor_fraction(), 176 latest_cms_sum_concurrent_phases_time_secs); 177 } 178 return latest_cms_sum_concurrent_phases_time_secs; 179 } 180 181 void CMSAdaptiveSizePolicy::update_minor_pause_old_estimator( 182 double minor_pause_in_ms) { 183 // Get the equivalent of the free space 184 // that is available for promotions in the CMS generation 185 // and use that to update _minor_pause_old_estimator 186 187 // Don't implement this until it is needed. A warning is 188 // printed if _minor_pause_old_estimator is used. 189 } 190 191 void CMSAdaptiveSizePolicy::concurrent_marking_begin() { 192 if (PrintAdaptiveSizePolicy && Verbose) { 193 gclog_or_tty->print(" "); 194 gclog_or_tty->stamp(); 195 gclog_or_tty->print(": concurrent_marking_begin "); 196 } 197 // Update the interval time 198 _concurrent_timer.stop(); 199 _latest_cms_collection_end_to_collection_start_secs = _concurrent_timer.seconds(); 200 if (PrintAdaptiveSizePolicy && Verbose) { 201 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_begin: " 202 "mutator time %f", _latest_cms_collection_end_to_collection_start_secs); 203 } 204 _concurrent_timer.reset(); 205 _concurrent_timer.start(); 206 } 207 208 void CMSAdaptiveSizePolicy::concurrent_marking_end() { 209 if (PrintAdaptiveSizePolicy && Verbose) { 210 gclog_or_tty->stamp(); 211 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_end()"); 212 } 213 214 _concurrent_timer.stop(); 215 _latest_cms_concurrent_marking_time_secs = _concurrent_timer.seconds(); 216 217 if (PrintAdaptiveSizePolicy && Verbose) { 218 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_marking_end" 219 ":concurrent marking time (s) %f", 220 _latest_cms_concurrent_marking_time_secs); 221 } 222 } 223 224 void CMSAdaptiveSizePolicy::concurrent_precleaning_begin() { 225 if (PrintAdaptiveSizePolicy && Verbose) { 226 gclog_or_tty->stamp(); 227 gclog_or_tty->print_cr( 228 "CMSAdaptiveSizePolicy::concurrent_precleaning_begin()"); 229 } 230 _concurrent_timer.reset(); 231 _concurrent_timer.start(); 232 } 233 234 235 void CMSAdaptiveSizePolicy::concurrent_precleaning_end() { 236 if (PrintAdaptiveSizePolicy && Verbose) { 237 gclog_or_tty->stamp(); 238 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_precleaning_end()"); 239 } 240 241 _concurrent_timer.stop(); 242 // May be set again by a second call during the same collection. 243 _latest_cms_concurrent_precleaning_time_secs = _concurrent_timer.seconds(); 244 245 if (PrintAdaptiveSizePolicy && Verbose) { 246 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_precleaning_end" 247 ":concurrent precleaning time (s) %f", 248 _latest_cms_concurrent_precleaning_time_secs); 249 } 250 } 251 252 void CMSAdaptiveSizePolicy::concurrent_sweeping_begin() { 253 if (PrintAdaptiveSizePolicy && Verbose) { 254 gclog_or_tty->stamp(); 255 gclog_or_tty->print_cr( 256 "CMSAdaptiveSizePolicy::concurrent_sweeping_begin()"); 257 } 258 _concurrent_timer.reset(); 259 _concurrent_timer.start(); 260 } 261 262 263 void CMSAdaptiveSizePolicy::concurrent_sweeping_end() { 264 if (PrintAdaptiveSizePolicy && Verbose) { 265 gclog_or_tty->stamp(); 266 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_sweeping_end()"); 267 } 268 269 _concurrent_timer.stop(); 270 _latest_cms_concurrent_sweeping_time_secs = _concurrent_timer.seconds(); 271 272 if (PrintAdaptiveSizePolicy && Verbose) { 273 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_sweeping_end" 274 ":concurrent sweeping time (s) %f", 275 _latest_cms_concurrent_sweeping_time_secs); 276 } 277 } 278 279 void CMSAdaptiveSizePolicy::concurrent_phases_end(GCCause::Cause gc_cause, 280 size_t cur_eden, 281 size_t cur_promo) { 282 if (PrintAdaptiveSizePolicy && Verbose) { 283 gclog_or_tty->print(" "); 284 gclog_or_tty->stamp(); 285 gclog_or_tty->print(": concurrent_phases_end "); 286 } 287 288 // Update the concurrent timer 289 _concurrent_timer.stop(); 290 291 if (gc_cause != GCCause::_java_lang_system_gc || 292 UseAdaptiveSizePolicyWithSystemGC) { 293 294 avg_cms_free()->sample(cur_promo); 295 double latest_cms_sum_concurrent_phases_time_secs = 296 concurrent_collection_time(); 297 298 _avg_concurrent_time->sample(latest_cms_sum_concurrent_phases_time_secs); 299 300 // Cost of collection (unit-less) 301 302 // Total interval for collection. May not be valid. Tests 303 // below determine whether to use this. 304 // 305 if (PrintAdaptiveSizePolicy && Verbose) { 306 gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::concurrent_phases_end \n" 307 "_latest_cms_reset_end_to_initial_mark_start_secs %f \n" 308 "_latest_cms_initial_mark_start_to_end_time_secs %f \n" 309 "_latest_cms_remark_start_to_end_time_secs %f \n" 310 "_latest_cms_concurrent_marking_time_secs %f \n" 311 "_latest_cms_concurrent_precleaning_time_secs %f \n" 312 "_latest_cms_concurrent_sweeping_time_secs %f \n" 313 "latest_cms_sum_concurrent_phases_time_secs %f \n" 314 "_latest_cms_collection_end_to_collection_start_secs %f \n" 315 "concurrent_processor_fraction %f", 316 _latest_cms_reset_end_to_initial_mark_start_secs, 317 _latest_cms_initial_mark_start_to_end_time_secs, 318 _latest_cms_remark_start_to_end_time_secs, 319 _latest_cms_concurrent_marking_time_secs, 320 _latest_cms_concurrent_precleaning_time_secs, 321 _latest_cms_concurrent_sweeping_time_secs, 322 latest_cms_sum_concurrent_phases_time_secs, 323 _latest_cms_collection_end_to_collection_start_secs, 324 concurrent_processor_fraction()); 325 } 326 double interval_in_seconds = 327 _latest_cms_initial_mark_start_to_end_time_secs + 328 _latest_cms_remark_start_to_end_time_secs + 329 latest_cms_sum_concurrent_phases_time_secs + 330 _latest_cms_collection_end_to_collection_start_secs; 331 assert(interval_in_seconds >= 0.0, 332 "Bad interval between cms collections"); 333 334 // Sample for performance counter 335 avg_concurrent_interval()->sample(interval_in_seconds); 336 337 // STW costs (initial and remark pauses) 338 // Cost of collection (unit-less) 339 assert(_latest_cms_initial_mark_start_to_end_time_secs >= 0.0, 340 "Bad initial mark pause"); 341 assert(_latest_cms_remark_start_to_end_time_secs >= 0.0, 342 "Bad remark pause"); 343 double STW_time_in_seconds = 344 _latest_cms_initial_mark_start_to_end_time_secs + 345 _latest_cms_remark_start_to_end_time_secs; 346 double STW_collection_cost = 0.0; 347 if (interval_in_seconds > 0.0) { 348 // cost for the STW phases of the concurrent collection. 349 STW_collection_cost = STW_time_in_seconds / interval_in_seconds; 350 avg_cms_STW_gc_cost()->sample(STW_collection_cost); 351 } 352 if (PrintAdaptiveSizePolicy && Verbose) { 353 gclog_or_tty->print("cmsAdaptiveSizePolicy::STW_collection_end: " 354 "STW gc cost: %f average: %f", STW_collection_cost, 355 avg_cms_STW_gc_cost()->average()); 356 gclog_or_tty->print_cr(" STW pause: %f (ms) STW period %f (ms)", 357 (double) STW_time_in_seconds * MILLIUNITS, 358 (double) interval_in_seconds * MILLIUNITS); 359 } 360 361 double concurrent_cost = 0.0; 362 if (latest_cms_sum_concurrent_phases_time_secs > 0.0) { 363 concurrent_cost = concurrent_collection_cost(interval_in_seconds); 364 365 avg_concurrent_gc_cost()->sample(concurrent_cost); 366 // Average this ms cost into all the other types gc costs 367 368 if (PrintAdaptiveSizePolicy && Verbose) { 369 gclog_or_tty->print("cmsAdaptiveSizePolicy::concurrent_phases_end: " 370 "concurrent gc cost: %f average: %f", 371 concurrent_cost, 372 _avg_concurrent_gc_cost->average()); 373 gclog_or_tty->print_cr(" concurrent time: %f (ms) cms period %f (ms)" 374 " processor fraction: %f", 375 latest_cms_sum_concurrent_phases_time_secs * MILLIUNITS, 376 interval_in_seconds * MILLIUNITS, 377 concurrent_processor_fraction()); 378 } 379 } 380 double total_collection_cost = STW_collection_cost + concurrent_cost; 381 avg_major_gc_cost()->sample(total_collection_cost); 382 383 // Gather information for estimating future behavior 384 double initial_pause_in_ms = _latest_cms_initial_mark_start_to_end_time_secs * MILLIUNITS; 385 double remark_pause_in_ms = _latest_cms_remark_start_to_end_time_secs * MILLIUNITS; 386 387 double cur_promo_size_in_mbytes = ((double)cur_promo)/((double)M); 388 initial_pause_old_estimator()->update(cur_promo_size_in_mbytes, 389 initial_pause_in_ms); 390 remark_pause_old_estimator()->update(cur_promo_size_in_mbytes, 391 remark_pause_in_ms); 392 major_collection_estimator()->update(cur_promo_size_in_mbytes, 393 total_collection_cost); 394 395 // This estimate uses the average eden size. It could also 396 // have used the latest eden size. Which is better? 397 double cur_eden_size_in_mbytes = ((double)cur_eden)/((double) M); 398 initial_pause_young_estimator()->update(cur_eden_size_in_mbytes, 399 initial_pause_in_ms); 400 remark_pause_young_estimator()->update(cur_eden_size_in_mbytes, 401 remark_pause_in_ms); 402 } 403 404 clear_internal_time_intervals(); 405 406 set_first_after_collection(); 407 408 // The concurrent phases keeps track of it's own mutator interval 409 // with this timer. This allows the stop-the-world phase to 410 // be included in the mutator time so that the stop-the-world time 411 // is not double counted. Reset and start it. 412 _concurrent_timer.reset(); 413 _concurrent_timer.start(); 414 415 // The mutator time between STW phases does not include the 416 // concurrent collection time. 417 _STW_timer.reset(); 418 _STW_timer.start(); 419 } 420 421 void CMSAdaptiveSizePolicy::checkpoint_roots_initial_begin() { 422 // Update the interval time 423 _STW_timer.stop(); 424 _latest_cms_reset_end_to_initial_mark_start_secs = _STW_timer.seconds(); 425 // Reset for the initial mark 426 _STW_timer.reset(); 427 _STW_timer.start(); 428 } 429 430 void CMSAdaptiveSizePolicy::checkpoint_roots_initial_end( 431 GCCause::Cause gc_cause) { 432 _STW_timer.stop(); 433 434 if (gc_cause != GCCause::_java_lang_system_gc || 435 UseAdaptiveSizePolicyWithSystemGC) { 436 _latest_cms_initial_mark_start_to_end_time_secs = _STW_timer.seconds(); 437 avg_initial_pause()->sample(_latest_cms_initial_mark_start_to_end_time_secs); 438 439 if (PrintAdaptiveSizePolicy && Verbose) { 440 gclog_or_tty->print( 441 "cmsAdaptiveSizePolicy::checkpoint_roots_initial_end: " 442 "initial pause: %f ", _latest_cms_initial_mark_start_to_end_time_secs); 443 } 444 } 445 446 _STW_timer.reset(); 447 _STW_timer.start(); 448 } 449 450 void CMSAdaptiveSizePolicy::checkpoint_roots_final_begin() { 451 _STW_timer.stop(); 452 _latest_cms_initial_mark_end_to_remark_start_secs = _STW_timer.seconds(); 453 // Start accumumlating time for the remark in the STW timer. 454 _STW_timer.reset(); 455 _STW_timer.start(); 456 } 457 458 void CMSAdaptiveSizePolicy::checkpoint_roots_final_end( 459 GCCause::Cause gc_cause) { 460 _STW_timer.stop(); 461 if (gc_cause != GCCause::_java_lang_system_gc || 462 UseAdaptiveSizePolicyWithSystemGC) { 463 // Total initial mark pause + remark pause. 464 _latest_cms_remark_start_to_end_time_secs = _STW_timer.seconds(); 465 double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + 466 _latest_cms_remark_start_to_end_time_secs; 467 double STW_time_in_ms = STW_time_in_seconds * MILLIUNITS; 468 469 avg_remark_pause()->sample(_latest_cms_remark_start_to_end_time_secs); 470 471 // Sample total for initial mark + remark 472 avg_cms_STW_time()->sample(STW_time_in_seconds); 473 474 if (PrintAdaptiveSizePolicy && Verbose) { 475 gclog_or_tty->print("cmsAdaptiveSizePolicy::checkpoint_roots_final_end: " 476 "remark pause: %f", _latest_cms_remark_start_to_end_time_secs); 477 } 478 479 } 480 // Don't start the STW times here because the concurrent 481 // sweep and reset has not happened. 482 // Keep the old comment above in case I don't understand 483 // what is going on but now 484 // Start the STW timer because it is used by ms_collection_begin() 485 // and ms_collection_end() to get the sweep time if a MS is being 486 // done in the foreground. 487 _STW_timer.reset(); 488 _STW_timer.start(); 489 } 490 491 void CMSAdaptiveSizePolicy::msc_collection_begin() { 492 if (PrintAdaptiveSizePolicy && Verbose) { 493 gclog_or_tty->print(" "); 494 gclog_or_tty->stamp(); 495 gclog_or_tty->print(": msc_collection_begin "); 496 } 497 _STW_timer.stop(); 498 _latest_cms_msc_end_to_msc_start_time_secs = _STW_timer.seconds(); 499 if (PrintAdaptiveSizePolicy && Verbose) { 500 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::msc_collection_begin: " 501 "mutator time %f", 502 _latest_cms_msc_end_to_msc_start_time_secs); 503 } 504 avg_msc_interval()->sample(_latest_cms_msc_end_to_msc_start_time_secs); 505 _STW_timer.reset(); 506 _STW_timer.start(); 507 } 508 509 void CMSAdaptiveSizePolicy::msc_collection_end(GCCause::Cause gc_cause) { 510 if (PrintAdaptiveSizePolicy && Verbose) { 511 gclog_or_tty->print(" "); 512 gclog_or_tty->stamp(); 513 gclog_or_tty->print(": msc_collection_end "); 514 } 515 _STW_timer.stop(); 516 if (gc_cause != GCCause::_java_lang_system_gc || 517 UseAdaptiveSizePolicyWithSystemGC) { 518 double msc_pause_in_seconds = _STW_timer.seconds(); 519 if ((_latest_cms_msc_end_to_msc_start_time_secs > 0.0) && 520 (msc_pause_in_seconds > 0.0)) { 521 avg_msc_pause()->sample(msc_pause_in_seconds); 522 double mutator_time_in_seconds = 0.0; 523 if (_latest_cms_collection_end_to_collection_start_secs == 0.0) { 524 // This assertion may fail because of time stamp gradularity. 525 // Comment it out and investiage it at a later time. The large 526 // time stamp granularity occurs on some older linux systems. 527 #ifndef CLOCK_GRANULARITY_TOO_LARGE 528 assert((_latest_cms_concurrent_marking_time_secs == 0.0) && 529 (_latest_cms_concurrent_precleaning_time_secs == 0.0) && 530 (_latest_cms_concurrent_sweeping_time_secs == 0.0), 531 "There should not be any concurrent time"); 532 #endif 533 // A concurrent collection did not start. Mutator time 534 // between collections comes from the STW MSC timer. 535 mutator_time_in_seconds = _latest_cms_msc_end_to_msc_start_time_secs; 536 } else { 537 // The concurrent collection did start so count the mutator 538 // time to the start of the concurrent collection. In this 539 // case the _latest_cms_msc_end_to_msc_start_time_secs measures 540 // the time between the initial mark or remark and the 541 // start of the MSC. That has no real meaning. 542 mutator_time_in_seconds = _latest_cms_collection_end_to_collection_start_secs; 543 } 544 545 double latest_cms_sum_concurrent_phases_time_secs = 546 concurrent_collection_time(); 547 double interval_in_seconds = 548 mutator_time_in_seconds + 549 _latest_cms_initial_mark_start_to_end_time_secs + 550 _latest_cms_remark_start_to_end_time_secs + 551 latest_cms_sum_concurrent_phases_time_secs + 552 msc_pause_in_seconds; 553 554 if (PrintAdaptiveSizePolicy && Verbose) { 555 gclog_or_tty->print_cr(" interval_in_seconds %f \n" 556 " mutator_time_in_seconds %f \n" 557 " _latest_cms_initial_mark_start_to_end_time_secs %f\n" 558 " _latest_cms_remark_start_to_end_time_secs %f\n" 559 " latest_cms_sum_concurrent_phases_time_secs %f\n" 560 " msc_pause_in_seconds %f\n", 561 interval_in_seconds, 562 mutator_time_in_seconds, 563 _latest_cms_initial_mark_start_to_end_time_secs, 564 _latest_cms_remark_start_to_end_time_secs, 565 latest_cms_sum_concurrent_phases_time_secs, 566 msc_pause_in_seconds); 567 } 568 569 // The concurrent cost is wasted cost but it should be 570 // included. 571 double concurrent_cost = concurrent_collection_cost(interval_in_seconds); 572 573 // Initial mark and remark, also wasted. 574 double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + 575 _latest_cms_remark_start_to_end_time_secs; 576 double STW_collection_cost = 577 collection_cost(STW_time_in_seconds, interval_in_seconds) + 578 concurrent_cost; 579 580 if (PrintAdaptiveSizePolicy && Verbose) { 581 gclog_or_tty->print_cr(" msc_collection_end:\n" 582 "_latest_cms_collection_end_to_collection_start_secs %f\n" 583 "_latest_cms_msc_end_to_msc_start_time_secs %f\n" 584 "_latest_cms_initial_mark_start_to_end_time_secs %f\n" 585 "_latest_cms_remark_start_to_end_time_secs %f\n" 586 "latest_cms_sum_concurrent_phases_time_secs %f\n", 587 _latest_cms_collection_end_to_collection_start_secs, 588 _latest_cms_msc_end_to_msc_start_time_secs, 589 _latest_cms_initial_mark_start_to_end_time_secs, 590 _latest_cms_remark_start_to_end_time_secs, 591 latest_cms_sum_concurrent_phases_time_secs); 592 593 gclog_or_tty->print_cr(" msc_collection_end: \n" 594 "latest_cms_sum_concurrent_phases_time_secs %f\n" 595 "STW_time_in_seconds %f\n" 596 "msc_pause_in_seconds %f\n", 597 latest_cms_sum_concurrent_phases_time_secs, 598 STW_time_in_seconds, 599 msc_pause_in_seconds); 600 } 601 602 double cost = concurrent_cost + STW_collection_cost + 603 collection_cost(msc_pause_in_seconds, interval_in_seconds); 604 605 _avg_msc_gc_cost->sample(cost); 606 607 // Average this ms cost into all the other types gc costs 608 avg_major_gc_cost()->sample(cost); 609 610 // Sample for performance counter 611 _avg_msc_interval->sample(interval_in_seconds); 612 if (PrintAdaptiveSizePolicy && Verbose) { 613 gclog_or_tty->print("cmsAdaptiveSizePolicy::msc_collection_end: " 614 "MSC gc cost: %f average: %f", cost, 615 _avg_msc_gc_cost->average()); 616 617 double msc_pause_in_ms = msc_pause_in_seconds * MILLIUNITS; 618 gclog_or_tty->print_cr(" MSC pause: %f (ms) MSC period %f (ms)", 619 msc_pause_in_ms, (double) interval_in_seconds * MILLIUNITS); 620 } 621 } 622 } 623 624 clear_internal_time_intervals(); 625 626 // Can this call be put into the epilogue? 627 set_first_after_collection(); 628 629 // The concurrent phases keeps track of it's own mutator interval 630 // with this timer. This allows the stop-the-world phase to 631 // be included in the mutator time so that the stop-the-world time 632 // is not double counted. Reset and start it. 633 _concurrent_timer.stop(); 634 _concurrent_timer.reset(); 635 _concurrent_timer.start(); 636 637 _STW_timer.reset(); 638 _STW_timer.start(); 639 } 640 641 void CMSAdaptiveSizePolicy::ms_collection_begin() { 642 if (PrintAdaptiveSizePolicy && Verbose) { 643 gclog_or_tty->print(" "); 644 gclog_or_tty->stamp(); 645 gclog_or_tty->print(": ms_collection_begin "); 646 } 647 _STW_timer.stop(); 648 _latest_cms_ms_end_to_ms_start = _STW_timer.seconds(); 649 if (PrintAdaptiveSizePolicy && Verbose) { 650 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::ms_collection_begin: " 651 "mutator time %f", 652 _latest_cms_ms_end_to_ms_start); 653 } 654 avg_ms_interval()->sample(_STW_timer.seconds()); 655 _STW_timer.reset(); 656 _STW_timer.start(); 657 } 658 659 void CMSAdaptiveSizePolicy::ms_collection_end(GCCause::Cause gc_cause) { 660 if (PrintAdaptiveSizePolicy && Verbose) { 661 gclog_or_tty->print(" "); 662 gclog_or_tty->stamp(); 663 gclog_or_tty->print(": ms_collection_end "); 664 } 665 _STW_timer.stop(); 666 if (gc_cause != GCCause::_java_lang_system_gc || 667 UseAdaptiveSizePolicyWithSystemGC) { 668 // The MS collection is a foreground collection that does all 669 // the parts of a mostly concurrent collection. 670 // 671 // For this collection include the cost of the 672 // initial mark 673 // remark 674 // all concurrent time (scaled down by the 675 // concurrent_processor_fraction). Some 676 // may be zero if the baton was passed before 677 // it was reached. 678 // concurrent marking 679 // sweeping 680 // resetting 681 // STW after baton was passed (STW_in_foreground_in_seconds) 682 double STW_in_foreground_in_seconds = _STW_timer.seconds(); 683 684 double latest_cms_sum_concurrent_phases_time_secs = 685 concurrent_collection_time(); 686 if (PrintAdaptiveSizePolicy && Verbose) { 687 gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::ms_collecton_end " 688 "STW_in_foreground_in_seconds %f " 689 "_latest_cms_initial_mark_start_to_end_time_secs %f " 690 "_latest_cms_remark_start_to_end_time_secs %f " 691 "latest_cms_sum_concurrent_phases_time_secs %f " 692 "_latest_cms_ms_marking_start_to_end_time_secs %f " 693 "_latest_cms_ms_end_to_ms_start %f", 694 STW_in_foreground_in_seconds, 695 _latest_cms_initial_mark_start_to_end_time_secs, 696 _latest_cms_remark_start_to_end_time_secs, 697 latest_cms_sum_concurrent_phases_time_secs, 698 _latest_cms_ms_marking_start_to_end_time_secs, 699 _latest_cms_ms_end_to_ms_start); 700 } 701 702 double STW_marking_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + 703 _latest_cms_remark_start_to_end_time_secs; 704 #ifndef CLOCK_GRANULARITY_TOO_LARGE 705 assert(_latest_cms_ms_marking_start_to_end_time_secs == 0.0 || 706 latest_cms_sum_concurrent_phases_time_secs == 0.0, 707 "marking done twice?"); 708 #endif 709 double ms_time_in_seconds = STW_marking_in_seconds + 710 STW_in_foreground_in_seconds + 711 _latest_cms_ms_marking_start_to_end_time_secs + 712 scaled_concurrent_collection_time(); 713 avg_ms_pause()->sample(ms_time_in_seconds); 714 // Use the STW costs from the initial mark and remark plus 715 // the cost of the concurrent phase to calculate a 716 // collection cost. 717 double cost = 0.0; 718 if ((_latest_cms_ms_end_to_ms_start > 0.0) && 719 (ms_time_in_seconds > 0.0)) { 720 double interval_in_seconds = 721 _latest_cms_ms_end_to_ms_start + ms_time_in_seconds; 722 723 if (PrintAdaptiveSizePolicy && Verbose) { 724 gclog_or_tty->print_cr("\n ms_time_in_seconds %f " 725 "latest_cms_sum_concurrent_phases_time_secs %f " 726 "interval_in_seconds %f", 727 ms_time_in_seconds, 728 latest_cms_sum_concurrent_phases_time_secs, 729 interval_in_seconds); 730 } 731 732 cost = collection_cost(ms_time_in_seconds, interval_in_seconds); 733 734 _avg_ms_gc_cost->sample(cost); 735 // Average this ms cost into all the other types gc costs 736 avg_major_gc_cost()->sample(cost); 737 738 // Sample for performance counter 739 _avg_ms_interval->sample(interval_in_seconds); 740 } 741 if (PrintAdaptiveSizePolicy && Verbose) { 742 gclog_or_tty->print("cmsAdaptiveSizePolicy::ms_collection_end: " 743 "MS gc cost: %f average: %f", cost, _avg_ms_gc_cost->average()); 744 745 double ms_time_in_ms = ms_time_in_seconds * MILLIUNITS; 746 gclog_or_tty->print_cr(" MS pause: %f (ms) MS period %f (ms)", 747 ms_time_in_ms, 748 _latest_cms_ms_end_to_ms_start * MILLIUNITS); 749 } 750 } 751 752 // Consider putting this code (here to end) into a 753 // method for convenience. 754 clear_internal_time_intervals(); 755 756 set_first_after_collection(); 757 758 // The concurrent phases keeps track of it's own mutator interval 759 // with this timer. This allows the stop-the-world phase to 760 // be included in the mutator time so that the stop-the-world time 761 // is not double counted. Reset and start it. 762 _concurrent_timer.stop(); 763 _concurrent_timer.reset(); 764 _concurrent_timer.start(); 765 766 _STW_timer.reset(); 767 _STW_timer.start(); 768 } 769 770 void CMSAdaptiveSizePolicy::clear_internal_time_intervals() { 771 _latest_cms_reset_end_to_initial_mark_start_secs = 0.0; 772 _latest_cms_initial_mark_end_to_remark_start_secs = 0.0; 773 _latest_cms_collection_end_to_collection_start_secs = 0.0; 774 _latest_cms_concurrent_marking_time_secs = 0.0; 775 _latest_cms_concurrent_precleaning_time_secs = 0.0; 776 _latest_cms_concurrent_sweeping_time_secs = 0.0; 777 _latest_cms_msc_end_to_msc_start_time_secs = 0.0; 778 _latest_cms_ms_end_to_ms_start = 0.0; 779 _latest_cms_remark_start_to_end_time_secs = 0.0; 780 _latest_cms_initial_mark_start_to_end_time_secs = 0.0; 781 _latest_cms_ms_marking_start_to_end_time_secs = 0.0; 782 } 783 784 void CMSAdaptiveSizePolicy::clear_generation_free_space_flags() { 785 AdaptiveSizePolicy::clear_generation_free_space_flags(); 786 787 set_change_young_gen_for_maj_pauses(0); 788 } 789 790 void CMSAdaptiveSizePolicy::concurrent_phases_resume() { 791 if (PrintAdaptiveSizePolicy && Verbose) { 792 gclog_or_tty->stamp(); 793 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_phases_resume()"); 794 } 795 _concurrent_timer.start(); 796 } 797 798 double CMSAdaptiveSizePolicy::time_since_major_gc() const { 799 _concurrent_timer.stop(); 800 double time_since_cms_gc = _concurrent_timer.seconds(); 801 _concurrent_timer.start(); 802 _STW_timer.stop(); 803 double time_since_STW_gc = _STW_timer.seconds(); 804 _STW_timer.start(); 805 806 return MIN2(time_since_cms_gc, time_since_STW_gc); 807 } 808 809 double CMSAdaptiveSizePolicy::major_gc_interval_average_for_decay() const { 810 double cms_interval = _avg_concurrent_interval->average(); 811 double msc_interval = _avg_msc_interval->average(); 812 double ms_interval = _avg_ms_interval->average(); 813 814 return MAX3(cms_interval, msc_interval, ms_interval); 815 } 816 817 double CMSAdaptiveSizePolicy::cms_gc_cost() const { 818 return avg_major_gc_cost()->average(); 819 } 820 821 void CMSAdaptiveSizePolicy::ms_collection_marking_begin() { 822 _STW_timer.stop(); 823 // Start accumumlating time for the marking in the STW timer. 824 _STW_timer.reset(); 825 _STW_timer.start(); 826 } 827 828 void CMSAdaptiveSizePolicy::ms_collection_marking_end( 829 GCCause::Cause gc_cause) { 830 _STW_timer.stop(); 831 if (gc_cause != GCCause::_java_lang_system_gc || 832 UseAdaptiveSizePolicyWithSystemGC) { 833 _latest_cms_ms_marking_start_to_end_time_secs = _STW_timer.seconds(); 834 if (PrintAdaptiveSizePolicy && Verbose) { 835 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::" 836 "msc_collection_marking_end: mutator time %f", 837 _latest_cms_ms_marking_start_to_end_time_secs); 838 } 839 } 840 _STW_timer.reset(); 841 _STW_timer.start(); 842 } 843 844 double CMSAdaptiveSizePolicy::gc_cost() const { 845 double cms_gen_cost = cms_gc_cost(); 846 double result = MIN2(1.0, minor_gc_cost() + cms_gen_cost); 847 assert(result >= 0.0, "Both minor and major costs are non-negative"); 848 return result; 849 } 850 851 // Cost of collection (unit-less) 852 double CMSAdaptiveSizePolicy::collection_cost(double pause_in_seconds, 853 double interval_in_seconds) { 854 // Cost of collection (unit-less) 855 double cost = 0.0; 856 if ((interval_in_seconds > 0.0) && 857 (pause_in_seconds > 0.0)) { 858 cost = 859 pause_in_seconds / interval_in_seconds; 860 } 861 return cost; 862 } 863 864 size_t CMSAdaptiveSizePolicy::adjust_eden_for_pause_time(size_t cur_eden) { 865 size_t change = 0; 866 size_t desired_eden = cur_eden; 867 868 // reduce eden size 869 change = eden_decrement_aligned_down(cur_eden); 870 desired_eden = cur_eden - change; 871 872 if (PrintAdaptiveSizePolicy && Verbose) { 873 gclog_or_tty->print_cr( 874 "CMSAdaptiveSizePolicy::adjust_eden_for_pause_time " 875 "adjusting eden for pause time. " 876 " starting eden size " SIZE_FORMAT 877 " reduced eden size " SIZE_FORMAT 878 " eden delta " SIZE_FORMAT, 879 cur_eden, desired_eden, change); 880 } 881 882 return desired_eden; 883 } 884 885 size_t CMSAdaptiveSizePolicy::adjust_eden_for_throughput(size_t cur_eden) { 886 887 size_t desired_eden = cur_eden; 888 889 set_change_young_gen_for_throughput(increase_young_gen_for_througput_true); 890 891 size_t change = eden_increment_aligned_up(cur_eden); 892 size_t scaled_change = scale_by_gen_gc_cost(change, minor_gc_cost()); 893 894 if (cur_eden + scaled_change > cur_eden) { 895 desired_eden = cur_eden + scaled_change; 896 } 897 898 _young_gen_change_for_minor_throughput++; 899 900 if (PrintAdaptiveSizePolicy && Verbose) { 901 gclog_or_tty->print_cr( 902 "CMSAdaptiveSizePolicy::adjust_eden_for_throughput " 903 "adjusting eden for throughput. " 904 " starting eden size " SIZE_FORMAT 905 " increased eden size " SIZE_FORMAT 906 " eden delta " SIZE_FORMAT, 907 cur_eden, desired_eden, scaled_change); 908 } 909 910 return desired_eden; 911 } 912 913 size_t CMSAdaptiveSizePolicy::adjust_eden_for_footprint(size_t cur_eden) { 914 915 set_decrease_for_footprint(decrease_young_gen_for_footprint_true); 916 917 size_t change = eden_decrement(cur_eden); 918 size_t desired_eden_size = cur_eden - change; 919 920 if (PrintAdaptiveSizePolicy && Verbose) { 921 gclog_or_tty->print_cr( 922 "CMSAdaptiveSizePolicy::adjust_eden_for_footprint " 923 "adjusting eden for footprint. " 924 " starting eden size " SIZE_FORMAT 925 " reduced eden size " SIZE_FORMAT 926 " eden delta " SIZE_FORMAT, 927 cur_eden, desired_eden_size, change); 928 } 929 return desired_eden_size; 930 } 931 932 // The eden and promo versions should be combined if possible. 933 // They are the same except that the sizes of the decrement 934 // and increment are different for eden and promo. 935 size_t CMSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) { 936 size_t delta = eden_decrement(cur_eden); 937 return align_size_down(delta, generation_alignment()); 938 } 939 940 size_t CMSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) { 941 size_t delta = eden_increment(cur_eden); 942 return align_size_up(delta, generation_alignment()); 943 } 944 945 size_t CMSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) { 946 size_t delta = promo_decrement(cur_promo); 947 return align_size_down(delta, generation_alignment()); 948 } 949 950 size_t CMSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) { 951 size_t delta = promo_increment(cur_promo); 952 return align_size_up(delta, generation_alignment()); 953 } 954 955 956 void CMSAdaptiveSizePolicy::compute_young_generation_free_space(size_t cur_eden, 957 size_t max_eden_size) 958 { 959 size_t desired_eden_size = cur_eden; 960 size_t eden_limit = max_eden_size; 961 962 // Printout input 963 if (PrintGC && PrintAdaptiveSizePolicy) { 964 gclog_or_tty->print_cr( 965 "CMSAdaptiveSizePolicy::compute_young_generation_free_space: " 966 "cur_eden " SIZE_FORMAT, 967 cur_eden); 968 } 969 970 // Used for diagnostics 971 clear_generation_free_space_flags(); 972 973 if (_avg_minor_pause->padded_average() > gc_pause_goal_sec()) { 974 if (minor_pause_young_estimator()->decrement_will_decrease()) { 975 // If the minor pause is too long, shrink the young gen. 976 set_change_young_gen_for_min_pauses( 977 decrease_young_gen_for_min_pauses_true); 978 desired_eden_size = adjust_eden_for_pause_time(desired_eden_size); 979 } 980 } else if ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) || 981 (avg_initial_pause()->padded_average() > gc_pause_goal_sec())) { 982 // The remark or initial pauses are not meeting the goal. Should 983 // the generation be shrunk? 984 if (get_and_clear_first_after_collection() && 985 ((avg_remark_pause()->padded_average() > gc_pause_goal_sec() && 986 remark_pause_young_estimator()->decrement_will_decrease()) || 987 (avg_initial_pause()->padded_average() > gc_pause_goal_sec() && 988 initial_pause_young_estimator()->decrement_will_decrease()))) { 989 990 set_change_young_gen_for_maj_pauses( 991 decrease_young_gen_for_maj_pauses_true); 992 993 // If the remark or initial pause is too long and this is the 994 // first young gen collection after a cms collection, shrink 995 // the young gen. 996 desired_eden_size = adjust_eden_for_pause_time(desired_eden_size); 997 } 998 // If not the first young gen collection after a cms collection, 999 // don't do anything. In this case an adjustment has already 1000 // been made and the results of the adjustment has not yet been 1001 // measured. 1002 } else if ((minor_gc_cost() >= 0.0) && 1003 (adjusted_mutator_cost() < _throughput_goal)) { 1004 desired_eden_size = adjust_eden_for_throughput(desired_eden_size); 1005 } else { 1006 desired_eden_size = adjust_eden_for_footprint(desired_eden_size); 1007 } 1008 1009 if (PrintGC && PrintAdaptiveSizePolicy) { 1010 gclog_or_tty->print_cr( 1011 "CMSAdaptiveSizePolicy::compute_young_generation_free_space limits:" 1012 " desired_eden_size: " SIZE_FORMAT 1013 " old_eden_size: " SIZE_FORMAT, 1014 desired_eden_size, cur_eden); 1015 } 1016 1017 set_eden_size(desired_eden_size); 1018 } 1019 1020 size_t CMSAdaptiveSizePolicy::adjust_promo_for_pause_time(size_t cur_promo) { 1021 size_t change = 0; 1022 size_t desired_promo = cur_promo; 1023 // Move this test up to caller like the adjust_eden_for_pause_time() 1024 // call. 1025 if ((AdaptiveSizePausePolicy == 0) && 1026 ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) || 1027 (avg_initial_pause()->padded_average() > gc_pause_goal_sec()))) { 1028 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true); 1029 change = promo_decrement_aligned_down(cur_promo); 1030 desired_promo = cur_promo - change; 1031 } else if ((AdaptiveSizePausePolicy > 0) && 1032 (((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) && 1033 remark_pause_old_estimator()->decrement_will_decrease()) || 1034 ((avg_initial_pause()->padded_average() > gc_pause_goal_sec()) && 1035 initial_pause_old_estimator()->decrement_will_decrease()))) { 1036 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true); 1037 change = promo_decrement_aligned_down(cur_promo); 1038 desired_promo = cur_promo - change; 1039 } 1040 1041 if ((change != 0) &&PrintAdaptiveSizePolicy && Verbose) { 1042 gclog_or_tty->print_cr( 1043 "CMSAdaptiveSizePolicy::adjust_promo_for_pause_time " 1044 "adjusting promo for pause time. " 1045 " starting promo size " SIZE_FORMAT 1046 " reduced promo size " SIZE_FORMAT 1047 " promo delta " SIZE_FORMAT, 1048 cur_promo, desired_promo, change); 1049 } 1050 1051 return desired_promo; 1052 } 1053 1054 // Try to share this with PS. 1055 size_t CMSAdaptiveSizePolicy::scale_by_gen_gc_cost(size_t base_change, 1056 double gen_gc_cost) { 1057 1058 // Calculate the change to use for the tenured gen. 1059 size_t scaled_change = 0; 1060 // Can the increment to the generation be scaled? 1061 if (gc_cost() >= 0.0 && gen_gc_cost >= 0.0) { 1062 double scale_by_ratio = gen_gc_cost / gc_cost(); 1063 scaled_change = 1064 (size_t) (scale_by_ratio * (double) base_change); 1065 if (PrintAdaptiveSizePolicy && Verbose) { 1066 gclog_or_tty->print_cr( 1067 "Scaled tenured increment: " SIZE_FORMAT " by %f down to " 1068 SIZE_FORMAT, 1069 base_change, scale_by_ratio, scaled_change); 1070 } 1071 } else if (gen_gc_cost >= 0.0) { 1072 // Scaling is not going to work. If the major gc time is the 1073 // larger than the other GC costs, give it a full increment. 1074 if (gen_gc_cost >= (gc_cost() - gen_gc_cost)) { 1075 scaled_change = base_change; 1076 } 1077 } else { 1078 // Don't expect to get here but it's ok if it does 1079 // in the product build since the delta will be 0 1080 // and nothing will change. 1081 assert(false, "Unexpected value for gc costs"); 1082 } 1083 1084 return scaled_change; 1085 } 1086 1087 size_t CMSAdaptiveSizePolicy::adjust_promo_for_throughput(size_t cur_promo) { 1088 1089 size_t desired_promo = cur_promo; 1090 1091 set_change_old_gen_for_throughput(increase_old_gen_for_throughput_true); 1092 1093 size_t change = promo_increment_aligned_up(cur_promo); 1094 size_t scaled_change = scale_by_gen_gc_cost(change, major_gc_cost()); 1095 1096 if (cur_promo + scaled_change > cur_promo) { 1097 desired_promo = cur_promo + scaled_change; 1098 } 1099 1100 _old_gen_change_for_major_throughput++; 1101 1102 if (PrintAdaptiveSizePolicy && Verbose) { 1103 gclog_or_tty->print_cr( 1104 "CMSAdaptiveSizePolicy::adjust_promo_for_throughput " 1105 "adjusting promo for throughput. " 1106 " starting promo size " SIZE_FORMAT 1107 " increased promo size " SIZE_FORMAT 1108 " promo delta " SIZE_FORMAT, 1109 cur_promo, desired_promo, scaled_change); 1110 } 1111 1112 return desired_promo; 1113 } 1114 1115 size_t CMSAdaptiveSizePolicy::adjust_promo_for_footprint(size_t cur_promo, 1116 size_t cur_eden) { 1117 1118 set_decrease_for_footprint(decrease_young_gen_for_footprint_true); 1119 1120 size_t change = promo_decrement(cur_promo); 1121 size_t desired_promo_size = cur_promo - change; 1122 1123 if (PrintAdaptiveSizePolicy && Verbose) { 1124 gclog_or_tty->print_cr( 1125 "CMSAdaptiveSizePolicy::adjust_promo_for_footprint " 1126 "adjusting promo for footprint. " 1127 " starting promo size " SIZE_FORMAT 1128 " reduced promo size " SIZE_FORMAT 1129 " promo delta " SIZE_FORMAT, 1130 cur_promo, desired_promo_size, change); 1131 } 1132 return desired_promo_size; 1133 } 1134 1135 void CMSAdaptiveSizePolicy::compute_tenured_generation_free_space( 1136 size_t cur_tenured_free, 1137 size_t max_tenured_available, 1138 size_t cur_eden) { 1139 // This can be bad if the desired value grows/shrinks without 1140 // any connection to the read free space 1141 size_t desired_promo_size = promo_size(); 1142 size_t tenured_limit = max_tenured_available; 1143 1144 // Printout input 1145 if (PrintGC && PrintAdaptiveSizePolicy) { 1146 gclog_or_tty->print_cr( 1147 "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space: " 1148 "cur_tenured_free " SIZE_FORMAT 1149 " max_tenured_available " SIZE_FORMAT, 1150 cur_tenured_free, max_tenured_available); 1151 } 1152 1153 // Used for diagnostics 1154 clear_generation_free_space_flags(); 1155 1156 set_decide_at_full_gc(decide_at_full_gc_true); 1157 if (avg_remark_pause()->padded_average() > gc_pause_goal_sec() || 1158 avg_initial_pause()->padded_average() > gc_pause_goal_sec()) { 1159 desired_promo_size = adjust_promo_for_pause_time(cur_tenured_free); 1160 } else if (avg_minor_pause()->padded_average() > gc_pause_goal_sec()) { 1161 // Nothing to do since the minor collections are too large and 1162 // this method only deals with the cms generation. 1163 } else if ((cms_gc_cost() >= 0.0) && 1164 (adjusted_mutator_cost() < _throughput_goal)) { 1165 desired_promo_size = adjust_promo_for_throughput(cur_tenured_free); 1166 } else { 1167 desired_promo_size = adjust_promo_for_footprint(cur_tenured_free, 1168 cur_eden); 1169 } 1170 1171 if (PrintGC && PrintAdaptiveSizePolicy) { 1172 gclog_or_tty->print_cr( 1173 "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space limits:" 1174 " desired_promo_size: " SIZE_FORMAT 1175 " old_promo_size: " SIZE_FORMAT, 1176 desired_promo_size, cur_tenured_free); 1177 } 1178 1179 set_promo_size(desired_promo_size); 1180 } 1181 1182 int CMSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold( 1183 bool is_survivor_overflow, 1184 int tenuring_threshold, 1185 size_t survivor_limit) { 1186 assert(survivor_limit >= generation_alignment(), 1187 "survivor_limit too small"); 1188 assert((size_t)align_size_down(survivor_limit, generation_alignment()) 1189 == survivor_limit, "survivor_limit not aligned"); 1190 1191 // Change UsePSAdaptiveSurvivorSizePolicy -> UseAdaptiveSurvivorSizePolicy? 1192 if (!UsePSAdaptiveSurvivorSizePolicy || 1193 !young_gen_policy_is_ready()) { 1194 return tenuring_threshold; 1195 } 1196 1197 // We'll decide whether to increase or decrease the tenuring 1198 // threshold based partly on the newly computed survivor size 1199 // (if we hit the maximum limit allowed, we'll always choose to 1200 // decrement the threshold). 1201 bool incr_tenuring_threshold = false; 1202 bool decr_tenuring_threshold = false; 1203 1204 set_decrement_tenuring_threshold_for_gc_cost(false); 1205 set_increment_tenuring_threshold_for_gc_cost(false); 1206 set_decrement_tenuring_threshold_for_survivor_limit(false); 1207 1208 if (!is_survivor_overflow) { 1209 // Keep running averages on how much survived 1210 1211 // We use the tenuring threshold to equalize the cost of major 1212 // and minor collections. 1213 // ThresholdTolerance is used to indicate how sensitive the 1214 // tenuring threshold is to differences in cost betweent the 1215 // collection types. 1216 1217 // Get the times of interest. This involves a little work, so 1218 // we cache the values here. 1219 const double major_cost = major_gc_cost(); 1220 const double minor_cost = minor_gc_cost(); 1221 1222 if (minor_cost > major_cost * _threshold_tolerance_percent) { 1223 // Minor times are getting too long; lower the threshold so 1224 // less survives and more is promoted. 1225 decr_tenuring_threshold = true; 1226 set_decrement_tenuring_threshold_for_gc_cost(true); 1227 } else if (major_cost > minor_cost * _threshold_tolerance_percent) { 1228 // Major times are too long, so we want less promotion. 1229 incr_tenuring_threshold = true; 1230 set_increment_tenuring_threshold_for_gc_cost(true); 1231 } 1232 1233 } else { 1234 // Survivor space overflow occurred, so promoted and survived are 1235 // not accurate. We'll make our best guess by combining survived 1236 // and promoted and count them as survivors. 1237 // 1238 // We'll lower the tenuring threshold to see if we can correct 1239 // things. Also, set the survivor size conservatively. We're 1240 // trying to avoid many overflows from occurring if defnew size 1241 // is just too small. 1242 1243 decr_tenuring_threshold = true; 1244 } 1245 1246 // The padded average also maintains a deviation from the average; 1247 // we use this to see how good of an estimate we have of what survived. 1248 // We're trying to pad the survivor size as little as possible without 1249 // overflowing the survivor spaces. 1250 size_t target_size = align_size_up((size_t)_avg_survived->padded_average(), 1251 generation_alignment()); 1252 target_size = MAX2(target_size, generation_alignment()); 1253 1254 if (target_size > survivor_limit) { 1255 // Target size is bigger than we can handle. Let's also reduce 1256 // the tenuring threshold. 1257 target_size = survivor_limit; 1258 decr_tenuring_threshold = true; 1259 set_decrement_tenuring_threshold_for_survivor_limit(true); 1260 } 1261 1262 // Finally, increment or decrement the tenuring threshold, as decided above. 1263 // We test for decrementing first, as we might have hit the target size 1264 // limit. 1265 if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { 1266 if (tenuring_threshold > 1) { 1267 tenuring_threshold--; 1268 } 1269 } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { 1270 if (tenuring_threshold < MaxTenuringThreshold) { 1271 tenuring_threshold++; 1272 } 1273 } 1274 1275 // We keep a running average of the amount promoted which is used 1276 // to decide when we should collect the old generation (when 1277 // the amount of old gen free space is less than what we expect to 1278 // promote). 1279 1280 if (PrintAdaptiveSizePolicy) { 1281 // A little more detail if Verbose is on 1282 GenCollectedHeap* gch = GenCollectedHeap::heap(); 1283 if (Verbose) { 1284 gclog_or_tty->print( " avg_survived: %f" 1285 " avg_deviation: %f", 1286 _avg_survived->average(), 1287 _avg_survived->deviation()); 1288 } 1289 1290 gclog_or_tty->print( " avg_survived_padded_avg: %f", 1291 _avg_survived->padded_average()); 1292 1293 if (Verbose) { 1294 gclog_or_tty->print( " avg_promoted_avg: %f" 1295 " avg_promoted_dev: %f", 1296 gch->gc_stats(1)->avg_promoted()->average(), 1297 gch->gc_stats(1)->avg_promoted()->deviation()); 1298 } 1299 1300 gclog_or_tty->print( " avg_promoted_padded_avg: %f" 1301 " avg_pretenured_padded_avg: %f" 1302 " tenuring_thresh: %d" 1303 " target_size: " SIZE_FORMAT 1304 " survivor_limit: " SIZE_FORMAT, 1305 gch->gc_stats(1)->avg_promoted()->padded_average(), 1306 _avg_pretenured->padded_average(), 1307 tenuring_threshold, target_size, survivor_limit); 1308 gclog_or_tty->cr(); 1309 } 1310 1311 set_survivor_size(target_size); 1312 1313 return tenuring_threshold; 1314 } 1315 1316 bool CMSAdaptiveSizePolicy::get_and_clear_first_after_collection() { 1317 bool result = _first_after_collection; 1318 _first_after_collection = false; 1319 return result; 1320 } 1321 1322 bool CMSAdaptiveSizePolicy::print_adaptive_size_policy_on( 1323 outputStream* st) const { 1324 1325 if (!UseAdaptiveSizePolicy) return false; 1326 1327 GenCollectedHeap* gch = GenCollectedHeap::heap(); 1328 Generation* gen0 = gch->get_gen(0); 1329 DefNewGeneration* def_new = gen0->as_DefNewGeneration(); 1330 return 1331 AdaptiveSizePolicy::print_adaptive_size_policy_on( 1332 st, 1333 def_new->tenuring_threshold()); 1334 }