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_bsd 41 # include "os_bsd.inline.hpp" 42 #endif 43 elapsedTimer CMSAdaptiveSizePolicy::_concurrent_timer; 44 elapsedTimer CMSAdaptiveSizePolicy::_STW_timer; 45 46 // Defined if the granularity of the time measurements is potentially too large. 47 #define CLOCK_GRANULARITY_TOO_LARGE 48 49 CMSAdaptiveSizePolicy::CMSAdaptiveSizePolicy(size_t init_eden_size, 50 size_t init_promo_size, 51 size_t init_survivor_size, 52 double max_gc_minor_pause_sec, 53 double max_gc_pause_sec, 54 uint gc_cost_ratio) : 55 AdaptiveSizePolicy(init_eden_size, 56 init_promo_size, 57 init_survivor_size, 58 max_gc_pause_sec, 59 gc_cost_ratio) { 60 61 clear_internal_time_intervals(); 62 63 _processor_count = os::active_processor_count(); 64 65 if (CMSConcurrentMTEnabled && (ConcGCThreads > 1)) { 66 assert(_processor_count > 0, "Processor count is suspect"); 67 _concurrent_processor_count = MIN2((uint) ConcGCThreads, 68 (uint) _processor_count); 69 } else { 70 _concurrent_processor_count = 1; 71 } 72 73 _avg_concurrent_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 74 _avg_concurrent_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 75 _avg_concurrent_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 76 77 _avg_initial_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight, 78 PausePadding); 79 _avg_remark_pause = new AdaptivePaddedAverage(AdaptiveTimeWeight, 80 PausePadding); 81 82 _avg_cms_STW_time = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 83 _avg_cms_STW_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 84 85 _avg_cms_free = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 86 _avg_cms_free_at_sweep = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 87 _avg_cms_promo = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 88 89 // Mark-sweep-compact 90 _avg_msc_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 91 _avg_msc_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 92 _avg_msc_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 93 94 // Mark-sweep 95 _avg_ms_pause = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 96 _avg_ms_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 97 _avg_ms_gc_cost = new AdaptiveWeightedAverage(AdaptiveTimeWeight); 98 99 // Variables that estimate pause times as a function of generation 100 // size. 101 _remark_pause_old_estimator = 102 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 103 _initial_pause_old_estimator = 104 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 105 _remark_pause_young_estimator = 106 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 107 _initial_pause_young_estimator = 108 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); 109 110 // Alignment comes from that used in ReservedSpace. 111 _generation_alignment = os::vm_allocation_granularity(); 112 113 // Start the concurrent timer here so that the first 114 // concurrent_phases_begin() measures a finite mutator 115 // time. A finite mutator time is used to determine 116 // if a concurrent collection has been started. If this 117 // proves to be a problem, use some explicit flag to 118 // signal that a concurrent collection has been started. 119 _concurrent_timer.start(); 120 _STW_timer.start(); 121 } 122 123 double CMSAdaptiveSizePolicy::concurrent_processor_fraction() { 124 // For now assume no other daemon threads are taking alway 125 // cpu's from the application. 126 return ((double) _concurrent_processor_count / (double) _processor_count); 127 } 128 129 double CMSAdaptiveSizePolicy::concurrent_collection_cost( 130 double interval_in_seconds) { 131 // When the precleaning and sweeping phases use multiple 132 // threads, change one_processor_fraction to 133 // concurrent_processor_fraction(). 134 double one_processor_fraction = 1.0 / ((double) processor_count()); 135 double concurrent_cost = 136 collection_cost(_latest_cms_concurrent_marking_time_secs, 137 interval_in_seconds) * concurrent_processor_fraction() + 138 collection_cost(_latest_cms_concurrent_precleaning_time_secs, 139 interval_in_seconds) * one_processor_fraction + 140 collection_cost(_latest_cms_concurrent_sweeping_time_secs, 141 interval_in_seconds) * one_processor_fraction; 142 if (PrintAdaptiveSizePolicy && Verbose) { 143 gclog_or_tty->print_cr( 144 "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_cost(%f) " 145 "_latest_cms_concurrent_marking_cost %f " 146 "_latest_cms_concurrent_precleaning_cost %f " 147 "_latest_cms_concurrent_sweeping_cost %f " 148 "concurrent_processor_fraction %f " 149 "concurrent_cost %f ", 150 interval_in_seconds, 151 collection_cost(_latest_cms_concurrent_marking_time_secs, 152 interval_in_seconds), 153 collection_cost(_latest_cms_concurrent_precleaning_time_secs, 154 interval_in_seconds), 155 collection_cost(_latest_cms_concurrent_sweeping_time_secs, 156 interval_in_seconds), 157 concurrent_processor_fraction(), 158 concurrent_cost); 159 } 160 return concurrent_cost; 161 } 162 163 double CMSAdaptiveSizePolicy::concurrent_collection_time() { 164 double latest_cms_sum_concurrent_phases_time_secs = 165 _latest_cms_concurrent_marking_time_secs + 166 _latest_cms_concurrent_precleaning_time_secs + 167 _latest_cms_concurrent_sweeping_time_secs; 168 return latest_cms_sum_concurrent_phases_time_secs; 169 } 170 171 double CMSAdaptiveSizePolicy::scaled_concurrent_collection_time() { 172 // When the precleaning and sweeping phases use multiple 173 // threads, change one_processor_fraction to 174 // concurrent_processor_fraction(). 175 double one_processor_fraction = 1.0 / ((double) processor_count()); 176 double latest_cms_sum_concurrent_phases_time_secs = 177 _latest_cms_concurrent_marking_time_secs * concurrent_processor_fraction() + 178 _latest_cms_concurrent_precleaning_time_secs * one_processor_fraction + 179 _latest_cms_concurrent_sweeping_time_secs * one_processor_fraction ; 180 if (PrintAdaptiveSizePolicy && Verbose) { 181 gclog_or_tty->print_cr( 182 "\nCMSAdaptiveSizePolicy::scaled_concurrent_collection_time " 183 "_latest_cms_concurrent_marking_time_secs %f " 184 "_latest_cms_concurrent_precleaning_time_secs %f " 185 "_latest_cms_concurrent_sweeping_time_secs %f " 186 "concurrent_processor_fraction %f " 187 "latest_cms_sum_concurrent_phases_time_secs %f ", 188 _latest_cms_concurrent_marking_time_secs, 189 _latest_cms_concurrent_precleaning_time_secs, 190 _latest_cms_concurrent_sweeping_time_secs, 191 concurrent_processor_fraction(), 192 latest_cms_sum_concurrent_phases_time_secs); 193 } 194 return latest_cms_sum_concurrent_phases_time_secs; 195 } 196 197 void CMSAdaptiveSizePolicy::update_minor_pause_old_estimator( 198 double minor_pause_in_ms) { 199 // Get the equivalent of the free space 200 // that is available for promotions in the CMS generation 201 // and use that to update _minor_pause_old_estimator 202 203 // Don't implement this until it is needed. A warning is 204 // printed if _minor_pause_old_estimator is used. 205 } 206 207 void CMSAdaptiveSizePolicy::concurrent_marking_begin() { 208 if (PrintAdaptiveSizePolicy && Verbose) { 209 gclog_or_tty->print(" "); 210 gclog_or_tty->stamp(); 211 gclog_or_tty->print(": concurrent_marking_begin "); 212 } 213 // Update the interval time 214 _concurrent_timer.stop(); 215 _latest_cms_collection_end_to_collection_start_secs = _concurrent_timer.seconds(); 216 if (PrintAdaptiveSizePolicy && Verbose) { 217 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_begin: " 218 "mutator time %f", _latest_cms_collection_end_to_collection_start_secs); 219 } 220 _concurrent_timer.reset(); 221 _concurrent_timer.start(); 222 } 223 224 void CMSAdaptiveSizePolicy::concurrent_marking_end() { 225 if (PrintAdaptiveSizePolicy && Verbose) { 226 gclog_or_tty->stamp(); 227 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_marking_end()"); 228 } 229 230 _concurrent_timer.stop(); 231 _latest_cms_concurrent_marking_time_secs = _concurrent_timer.seconds(); 232 233 if (PrintAdaptiveSizePolicy && Verbose) { 234 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_marking_end" 235 ":concurrent marking time (s) %f", 236 _latest_cms_concurrent_marking_time_secs); 237 } 238 } 239 240 void CMSAdaptiveSizePolicy::concurrent_precleaning_begin() { 241 if (PrintAdaptiveSizePolicy && Verbose) { 242 gclog_or_tty->stamp(); 243 gclog_or_tty->print_cr( 244 "CMSAdaptiveSizePolicy::concurrent_precleaning_begin()"); 245 } 246 _concurrent_timer.reset(); 247 _concurrent_timer.start(); 248 } 249 250 251 void CMSAdaptiveSizePolicy::concurrent_precleaning_end() { 252 if (PrintAdaptiveSizePolicy && Verbose) { 253 gclog_or_tty->stamp(); 254 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_precleaning_end()"); 255 } 256 257 _concurrent_timer.stop(); 258 // May be set again by a second call during the same collection. 259 _latest_cms_concurrent_precleaning_time_secs = _concurrent_timer.seconds(); 260 261 if (PrintAdaptiveSizePolicy && Verbose) { 262 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_precleaning_end" 263 ":concurrent precleaning time (s) %f", 264 _latest_cms_concurrent_precleaning_time_secs); 265 } 266 } 267 268 void CMSAdaptiveSizePolicy::concurrent_sweeping_begin() { 269 if (PrintAdaptiveSizePolicy && Verbose) { 270 gclog_or_tty->stamp(); 271 gclog_or_tty->print_cr( 272 "CMSAdaptiveSizePolicy::concurrent_sweeping_begin()"); 273 } 274 _concurrent_timer.reset(); 275 _concurrent_timer.start(); 276 } 277 278 279 void CMSAdaptiveSizePolicy::concurrent_sweeping_end() { 280 if (PrintAdaptiveSizePolicy && Verbose) { 281 gclog_or_tty->stamp(); 282 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_sweeping_end()"); 283 } 284 285 _concurrent_timer.stop(); 286 _latest_cms_concurrent_sweeping_time_secs = _concurrent_timer.seconds(); 287 288 if (PrintAdaptiveSizePolicy && Verbose) { 289 gclog_or_tty->print_cr("\n CMSAdaptiveSizePolicy::concurrent_sweeping_end" 290 ":concurrent sweeping time (s) %f", 291 _latest_cms_concurrent_sweeping_time_secs); 292 } 293 } 294 295 void CMSAdaptiveSizePolicy::concurrent_phases_end(GCCause::Cause gc_cause, 296 size_t cur_eden, 297 size_t cur_promo) { 298 if (PrintAdaptiveSizePolicy && Verbose) { 299 gclog_or_tty->print(" "); 300 gclog_or_tty->stamp(); 301 gclog_or_tty->print(": concurrent_phases_end "); 302 } 303 304 // Update the concurrent timer 305 _concurrent_timer.stop(); 306 307 if (gc_cause != GCCause::_java_lang_system_gc || 308 UseAdaptiveSizePolicyWithSystemGC) { 309 310 avg_cms_free()->sample(cur_promo); 311 double latest_cms_sum_concurrent_phases_time_secs = 312 concurrent_collection_time(); 313 314 _avg_concurrent_time->sample(latest_cms_sum_concurrent_phases_time_secs); 315 316 // Cost of collection (unit-less) 317 318 // Total interval for collection. May not be valid. Tests 319 // below determine whether to use this. 320 // 321 if (PrintAdaptiveSizePolicy && Verbose) { 322 gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::concurrent_phases_end \n" 323 "_latest_cms_reset_end_to_initial_mark_start_secs %f \n" 324 "_latest_cms_initial_mark_start_to_end_time_secs %f \n" 325 "_latest_cms_remark_start_to_end_time_secs %f \n" 326 "_latest_cms_concurrent_marking_time_secs %f \n" 327 "_latest_cms_concurrent_precleaning_time_secs %f \n" 328 "_latest_cms_concurrent_sweeping_time_secs %f \n" 329 "latest_cms_sum_concurrent_phases_time_secs %f \n" 330 "_latest_cms_collection_end_to_collection_start_secs %f \n" 331 "concurrent_processor_fraction %f", 332 _latest_cms_reset_end_to_initial_mark_start_secs, 333 _latest_cms_initial_mark_start_to_end_time_secs, 334 _latest_cms_remark_start_to_end_time_secs, 335 _latest_cms_concurrent_marking_time_secs, 336 _latest_cms_concurrent_precleaning_time_secs, 337 _latest_cms_concurrent_sweeping_time_secs, 338 latest_cms_sum_concurrent_phases_time_secs, 339 _latest_cms_collection_end_to_collection_start_secs, 340 concurrent_processor_fraction()); 341 } 342 double interval_in_seconds = 343 _latest_cms_initial_mark_start_to_end_time_secs + 344 _latest_cms_remark_start_to_end_time_secs + 345 latest_cms_sum_concurrent_phases_time_secs + 346 _latest_cms_collection_end_to_collection_start_secs; 347 assert(interval_in_seconds >= 0.0, 348 "Bad interval between cms collections"); 349 350 // Sample for performance counter 351 avg_concurrent_interval()->sample(interval_in_seconds); 352 353 // STW costs (initial and remark pauses) 354 // Cost of collection (unit-less) 355 assert(_latest_cms_initial_mark_start_to_end_time_secs >= 0.0, 356 "Bad initial mark pause"); 357 assert(_latest_cms_remark_start_to_end_time_secs >= 0.0, 358 "Bad remark pause"); 359 double STW_time_in_seconds = 360 _latest_cms_initial_mark_start_to_end_time_secs + 361 _latest_cms_remark_start_to_end_time_secs; 362 double STW_collection_cost = 0.0; 363 if (interval_in_seconds > 0.0) { 364 // cost for the STW phases of the concurrent collection. 365 STW_collection_cost = STW_time_in_seconds / interval_in_seconds; 366 avg_cms_STW_gc_cost()->sample(STW_collection_cost); 367 } 368 if (PrintAdaptiveSizePolicy && Verbose) { 369 gclog_or_tty->print("cmsAdaptiveSizePolicy::STW_collection_end: " 370 "STW gc cost: %f average: %f", STW_collection_cost, 371 avg_cms_STW_gc_cost()->average()); 372 gclog_or_tty->print_cr(" STW pause: %f (ms) STW period %f (ms)", 373 (double) STW_time_in_seconds * MILLIUNITS, 374 (double) interval_in_seconds * MILLIUNITS); 375 } 376 377 double concurrent_cost = 0.0; 378 if (latest_cms_sum_concurrent_phases_time_secs > 0.0) { 379 concurrent_cost = concurrent_collection_cost(interval_in_seconds); 380 381 avg_concurrent_gc_cost()->sample(concurrent_cost); 382 // Average this ms cost into all the other types gc costs 383 384 if (PrintAdaptiveSizePolicy && Verbose) { 385 gclog_or_tty->print("cmsAdaptiveSizePolicy::concurrent_phases_end: " 386 "concurrent gc cost: %f average: %f", 387 concurrent_cost, 388 _avg_concurrent_gc_cost->average()); 389 gclog_or_tty->print_cr(" concurrent time: %f (ms) cms period %f (ms)" 390 " processor fraction: %f", 391 latest_cms_sum_concurrent_phases_time_secs * MILLIUNITS, 392 interval_in_seconds * MILLIUNITS, 393 concurrent_processor_fraction()); 394 } 395 } 396 double total_collection_cost = STW_collection_cost + concurrent_cost; 397 avg_major_gc_cost()->sample(total_collection_cost); 398 399 // Gather information for estimating future behavior 400 double initial_pause_in_ms = _latest_cms_initial_mark_start_to_end_time_secs * MILLIUNITS; 401 double remark_pause_in_ms = _latest_cms_remark_start_to_end_time_secs * MILLIUNITS; 402 403 double cur_promo_size_in_mbytes = ((double)cur_promo)/((double)M); 404 initial_pause_old_estimator()->update(cur_promo_size_in_mbytes, 405 initial_pause_in_ms); 406 remark_pause_old_estimator()->update(cur_promo_size_in_mbytes, 407 remark_pause_in_ms); 408 major_collection_estimator()->update(cur_promo_size_in_mbytes, 409 total_collection_cost); 410 411 // This estimate uses the average eden size. It could also 412 // have used the latest eden size. Which is better? 413 double cur_eden_size_in_mbytes = ((double)cur_eden)/((double) M); 414 initial_pause_young_estimator()->update(cur_eden_size_in_mbytes, 415 initial_pause_in_ms); 416 remark_pause_young_estimator()->update(cur_eden_size_in_mbytes, 417 remark_pause_in_ms); 418 } 419 420 clear_internal_time_intervals(); 421 422 set_first_after_collection(); 423 424 // The concurrent phases keeps track of it's own mutator interval 425 // with this timer. This allows the stop-the-world phase to 426 // be included in the mutator time so that the stop-the-world time 427 // is not double counted. Reset and start it. 428 _concurrent_timer.reset(); 429 _concurrent_timer.start(); 430 431 // The mutator time between STW phases does not include the 432 // concurrent collection time. 433 _STW_timer.reset(); 434 _STW_timer.start(); 435 } 436 437 void CMSAdaptiveSizePolicy::checkpoint_roots_initial_begin() { 438 // Update the interval time 439 _STW_timer.stop(); 440 _latest_cms_reset_end_to_initial_mark_start_secs = _STW_timer.seconds(); 441 // Reset for the initial mark 442 _STW_timer.reset(); 443 _STW_timer.start(); 444 } 445 446 void CMSAdaptiveSizePolicy::checkpoint_roots_initial_end( 447 GCCause::Cause gc_cause) { 448 _STW_timer.stop(); 449 450 if (gc_cause != GCCause::_java_lang_system_gc || 451 UseAdaptiveSizePolicyWithSystemGC) { 452 _latest_cms_initial_mark_start_to_end_time_secs = _STW_timer.seconds(); 453 avg_initial_pause()->sample(_latest_cms_initial_mark_start_to_end_time_secs); 454 455 if (PrintAdaptiveSizePolicy && Verbose) { 456 gclog_or_tty->print( 457 "cmsAdaptiveSizePolicy::checkpoint_roots_initial_end: " 458 "initial pause: %f ", _latest_cms_initial_mark_start_to_end_time_secs); 459 } 460 } 461 462 _STW_timer.reset(); 463 _STW_timer.start(); 464 } 465 466 void CMSAdaptiveSizePolicy::checkpoint_roots_final_begin() { 467 _STW_timer.stop(); 468 _latest_cms_initial_mark_end_to_remark_start_secs = _STW_timer.seconds(); 469 // Start accumumlating time for the remark in the STW timer. 470 _STW_timer.reset(); 471 _STW_timer.start(); 472 } 473 474 void CMSAdaptiveSizePolicy::checkpoint_roots_final_end( 475 GCCause::Cause gc_cause) { 476 _STW_timer.stop(); 477 if (gc_cause != GCCause::_java_lang_system_gc || 478 UseAdaptiveSizePolicyWithSystemGC) { 479 // Total initial mark pause + remark pause. 480 _latest_cms_remark_start_to_end_time_secs = _STW_timer.seconds(); 481 double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + 482 _latest_cms_remark_start_to_end_time_secs; 483 double STW_time_in_ms = STW_time_in_seconds * MILLIUNITS; 484 485 avg_remark_pause()->sample(_latest_cms_remark_start_to_end_time_secs); 486 487 // Sample total for initial mark + remark 488 avg_cms_STW_time()->sample(STW_time_in_seconds); 489 490 if (PrintAdaptiveSizePolicy && Verbose) { 491 gclog_or_tty->print("cmsAdaptiveSizePolicy::checkpoint_roots_final_end: " 492 "remark pause: %f", _latest_cms_remark_start_to_end_time_secs); 493 } 494 495 } 496 // Don't start the STW times here because the concurrent 497 // sweep and reset has not happened. 498 // Keep the old comment above in case I don't understand 499 // what is going on but now 500 // Start the STW timer because it is used by ms_collection_begin() 501 // and ms_collection_end() to get the sweep time if a MS is being 502 // done in the foreground. 503 _STW_timer.reset(); 504 _STW_timer.start(); 505 } 506 507 void CMSAdaptiveSizePolicy::msc_collection_begin() { 508 if (PrintAdaptiveSizePolicy && Verbose) { 509 gclog_or_tty->print(" "); 510 gclog_or_tty->stamp(); 511 gclog_or_tty->print(": msc_collection_begin "); 512 } 513 _STW_timer.stop(); 514 _latest_cms_msc_end_to_msc_start_time_secs = _STW_timer.seconds(); 515 if (PrintAdaptiveSizePolicy && Verbose) { 516 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::msc_collection_begin: " 517 "mutator time %f", 518 _latest_cms_msc_end_to_msc_start_time_secs); 519 } 520 avg_msc_interval()->sample(_latest_cms_msc_end_to_msc_start_time_secs); 521 _STW_timer.reset(); 522 _STW_timer.start(); 523 } 524 525 void CMSAdaptiveSizePolicy::msc_collection_end(GCCause::Cause gc_cause) { 526 if (PrintAdaptiveSizePolicy && Verbose) { 527 gclog_or_tty->print(" "); 528 gclog_or_tty->stamp(); 529 gclog_or_tty->print(": msc_collection_end "); 530 } 531 _STW_timer.stop(); 532 if (gc_cause != GCCause::_java_lang_system_gc || 533 UseAdaptiveSizePolicyWithSystemGC) { 534 double msc_pause_in_seconds = _STW_timer.seconds(); 535 if ((_latest_cms_msc_end_to_msc_start_time_secs > 0.0) && 536 (msc_pause_in_seconds > 0.0)) { 537 avg_msc_pause()->sample(msc_pause_in_seconds); 538 double mutator_time_in_seconds = 0.0; 539 if (_latest_cms_collection_end_to_collection_start_secs == 0.0) { 540 // This assertion may fail because of time stamp gradularity. 541 // Comment it out and investiage it at a later time. The large 542 // time stamp granularity occurs on some older linux systems. 543 #ifndef CLOCK_GRANULARITY_TOO_LARGE 544 assert((_latest_cms_concurrent_marking_time_secs == 0.0) && 545 (_latest_cms_concurrent_precleaning_time_secs == 0.0) && 546 (_latest_cms_concurrent_sweeping_time_secs == 0.0), 547 "There should not be any concurrent time"); 548 #endif 549 // A concurrent collection did not start. Mutator time 550 // between collections comes from the STW MSC timer. 551 mutator_time_in_seconds = _latest_cms_msc_end_to_msc_start_time_secs; 552 } else { 553 // The concurrent collection did start so count the mutator 554 // time to the start of the concurrent collection. In this 555 // case the _latest_cms_msc_end_to_msc_start_time_secs measures 556 // the time between the initial mark or remark and the 557 // start of the MSC. That has no real meaning. 558 mutator_time_in_seconds = _latest_cms_collection_end_to_collection_start_secs; 559 } 560 561 double latest_cms_sum_concurrent_phases_time_secs = 562 concurrent_collection_time(); 563 double interval_in_seconds = 564 mutator_time_in_seconds + 565 _latest_cms_initial_mark_start_to_end_time_secs + 566 _latest_cms_remark_start_to_end_time_secs + 567 latest_cms_sum_concurrent_phases_time_secs + 568 msc_pause_in_seconds; 569 570 if (PrintAdaptiveSizePolicy && Verbose) { 571 gclog_or_tty->print_cr(" interval_in_seconds %f \n" 572 " mutator_time_in_seconds %f \n" 573 " _latest_cms_initial_mark_start_to_end_time_secs %f\n" 574 " _latest_cms_remark_start_to_end_time_secs %f\n" 575 " latest_cms_sum_concurrent_phases_time_secs %f\n" 576 " msc_pause_in_seconds %f\n", 577 interval_in_seconds, 578 mutator_time_in_seconds, 579 _latest_cms_initial_mark_start_to_end_time_secs, 580 _latest_cms_remark_start_to_end_time_secs, 581 latest_cms_sum_concurrent_phases_time_secs, 582 msc_pause_in_seconds); 583 } 584 585 // The concurrent cost is wasted cost but it should be 586 // included. 587 double concurrent_cost = concurrent_collection_cost(interval_in_seconds); 588 589 // Initial mark and remark, also wasted. 590 double STW_time_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + 591 _latest_cms_remark_start_to_end_time_secs; 592 double STW_collection_cost = 593 collection_cost(STW_time_in_seconds, interval_in_seconds) + 594 concurrent_cost; 595 596 if (PrintAdaptiveSizePolicy && Verbose) { 597 gclog_or_tty->print_cr(" msc_collection_end:\n" 598 "_latest_cms_collection_end_to_collection_start_secs %f\n" 599 "_latest_cms_msc_end_to_msc_start_time_secs %f\n" 600 "_latest_cms_initial_mark_start_to_end_time_secs %f\n" 601 "_latest_cms_remark_start_to_end_time_secs %f\n" 602 "latest_cms_sum_concurrent_phases_time_secs %f\n", 603 _latest_cms_collection_end_to_collection_start_secs, 604 _latest_cms_msc_end_to_msc_start_time_secs, 605 _latest_cms_initial_mark_start_to_end_time_secs, 606 _latest_cms_remark_start_to_end_time_secs, 607 latest_cms_sum_concurrent_phases_time_secs); 608 609 gclog_or_tty->print_cr(" msc_collection_end: \n" 610 "latest_cms_sum_concurrent_phases_time_secs %f\n" 611 "STW_time_in_seconds %f\n" 612 "msc_pause_in_seconds %f\n", 613 latest_cms_sum_concurrent_phases_time_secs, 614 STW_time_in_seconds, 615 msc_pause_in_seconds); 616 } 617 618 double cost = concurrent_cost + STW_collection_cost + 619 collection_cost(msc_pause_in_seconds, interval_in_seconds); 620 621 _avg_msc_gc_cost->sample(cost); 622 623 // Average this ms cost into all the other types gc costs 624 avg_major_gc_cost()->sample(cost); 625 626 // Sample for performance counter 627 _avg_msc_interval->sample(interval_in_seconds); 628 if (PrintAdaptiveSizePolicy && Verbose) { 629 gclog_or_tty->print("cmsAdaptiveSizePolicy::msc_collection_end: " 630 "MSC gc cost: %f average: %f", cost, 631 _avg_msc_gc_cost->average()); 632 633 double msc_pause_in_ms = msc_pause_in_seconds * MILLIUNITS; 634 gclog_or_tty->print_cr(" MSC pause: %f (ms) MSC period %f (ms)", 635 msc_pause_in_ms, (double) interval_in_seconds * MILLIUNITS); 636 } 637 } 638 } 639 640 clear_internal_time_intervals(); 641 642 // Can this call be put into the epilogue? 643 set_first_after_collection(); 644 645 // The concurrent phases keeps track of it's own mutator interval 646 // with this timer. This allows the stop-the-world phase to 647 // be included in the mutator time so that the stop-the-world time 648 // is not double counted. Reset and start it. 649 _concurrent_timer.stop(); 650 _concurrent_timer.reset(); 651 _concurrent_timer.start(); 652 653 _STW_timer.reset(); 654 _STW_timer.start(); 655 } 656 657 void CMSAdaptiveSizePolicy::ms_collection_begin() { 658 if (PrintAdaptiveSizePolicy && Verbose) { 659 gclog_or_tty->print(" "); 660 gclog_or_tty->stamp(); 661 gclog_or_tty->print(": ms_collection_begin "); 662 } 663 _STW_timer.stop(); 664 _latest_cms_ms_end_to_ms_start = _STW_timer.seconds(); 665 if (PrintAdaptiveSizePolicy && Verbose) { 666 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::ms_collection_begin: " 667 "mutator time %f", 668 _latest_cms_ms_end_to_ms_start); 669 } 670 avg_ms_interval()->sample(_STW_timer.seconds()); 671 _STW_timer.reset(); 672 _STW_timer.start(); 673 } 674 675 void CMSAdaptiveSizePolicy::ms_collection_end(GCCause::Cause gc_cause) { 676 if (PrintAdaptiveSizePolicy && Verbose) { 677 gclog_or_tty->print(" "); 678 gclog_or_tty->stamp(); 679 gclog_or_tty->print(": ms_collection_end "); 680 } 681 _STW_timer.stop(); 682 if (gc_cause != GCCause::_java_lang_system_gc || 683 UseAdaptiveSizePolicyWithSystemGC) { 684 // The MS collection is a foreground collection that does all 685 // the parts of a mostly concurrent collection. 686 // 687 // For this collection include the cost of the 688 // initial mark 689 // remark 690 // all concurrent time (scaled down by the 691 // concurrent_processor_fraction). Some 692 // may be zero if the baton was passed before 693 // it was reached. 694 // concurrent marking 695 // sweeping 696 // resetting 697 // STW after baton was passed (STW_in_foreground_in_seconds) 698 double STW_in_foreground_in_seconds = _STW_timer.seconds(); 699 700 double latest_cms_sum_concurrent_phases_time_secs = 701 concurrent_collection_time(); 702 if (PrintAdaptiveSizePolicy && Verbose) { 703 gclog_or_tty->print_cr("\nCMSAdaptiveSizePolicy::ms_collecton_end " 704 "STW_in_foreground_in_seconds %f " 705 "_latest_cms_initial_mark_start_to_end_time_secs %f " 706 "_latest_cms_remark_start_to_end_time_secs %f " 707 "latest_cms_sum_concurrent_phases_time_secs %f " 708 "_latest_cms_ms_marking_start_to_end_time_secs %f " 709 "_latest_cms_ms_end_to_ms_start %f", 710 STW_in_foreground_in_seconds, 711 _latest_cms_initial_mark_start_to_end_time_secs, 712 _latest_cms_remark_start_to_end_time_secs, 713 latest_cms_sum_concurrent_phases_time_secs, 714 _latest_cms_ms_marking_start_to_end_time_secs, 715 _latest_cms_ms_end_to_ms_start); 716 } 717 718 double STW_marking_in_seconds = _latest_cms_initial_mark_start_to_end_time_secs + 719 _latest_cms_remark_start_to_end_time_secs; 720 #ifndef CLOCK_GRANULARITY_TOO_LARGE 721 assert(_latest_cms_ms_marking_start_to_end_time_secs == 0.0 || 722 latest_cms_sum_concurrent_phases_time_secs == 0.0, 723 "marking done twice?"); 724 #endif 725 double ms_time_in_seconds = STW_marking_in_seconds + 726 STW_in_foreground_in_seconds + 727 _latest_cms_ms_marking_start_to_end_time_secs + 728 scaled_concurrent_collection_time(); 729 avg_ms_pause()->sample(ms_time_in_seconds); 730 // Use the STW costs from the initial mark and remark plus 731 // the cost of the concurrent phase to calculate a 732 // collection cost. 733 double cost = 0.0; 734 if ((_latest_cms_ms_end_to_ms_start > 0.0) && 735 (ms_time_in_seconds > 0.0)) { 736 double interval_in_seconds = 737 _latest_cms_ms_end_to_ms_start + ms_time_in_seconds; 738 739 if (PrintAdaptiveSizePolicy && Verbose) { 740 gclog_or_tty->print_cr("\n ms_time_in_seconds %f " 741 "latest_cms_sum_concurrent_phases_time_secs %f " 742 "interval_in_seconds %f", 743 ms_time_in_seconds, 744 latest_cms_sum_concurrent_phases_time_secs, 745 interval_in_seconds); 746 } 747 748 cost = collection_cost(ms_time_in_seconds, interval_in_seconds); 749 750 _avg_ms_gc_cost->sample(cost); 751 // Average this ms cost into all the other types gc costs 752 avg_major_gc_cost()->sample(cost); 753 754 // Sample for performance counter 755 _avg_ms_interval->sample(interval_in_seconds); 756 } 757 if (PrintAdaptiveSizePolicy && Verbose) { 758 gclog_or_tty->print("cmsAdaptiveSizePolicy::ms_collection_end: " 759 "MS gc cost: %f average: %f", cost, _avg_ms_gc_cost->average()); 760 761 double ms_time_in_ms = ms_time_in_seconds * MILLIUNITS; 762 gclog_or_tty->print_cr(" MS pause: %f (ms) MS period %f (ms)", 763 ms_time_in_ms, 764 _latest_cms_ms_end_to_ms_start * MILLIUNITS); 765 } 766 } 767 768 // Consider putting this code (here to end) into a 769 // method for convenience. 770 clear_internal_time_intervals(); 771 772 set_first_after_collection(); 773 774 // The concurrent phases keeps track of it's own mutator interval 775 // with this timer. This allows the stop-the-world phase to 776 // be included in the mutator time so that the stop-the-world time 777 // is not double counted. Reset and start it. 778 _concurrent_timer.stop(); 779 _concurrent_timer.reset(); 780 _concurrent_timer.start(); 781 782 _STW_timer.reset(); 783 _STW_timer.start(); 784 } 785 786 void CMSAdaptiveSizePolicy::clear_internal_time_intervals() { 787 _latest_cms_reset_end_to_initial_mark_start_secs = 0.0; 788 _latest_cms_initial_mark_end_to_remark_start_secs = 0.0; 789 _latest_cms_collection_end_to_collection_start_secs = 0.0; 790 _latest_cms_concurrent_marking_time_secs = 0.0; 791 _latest_cms_concurrent_precleaning_time_secs = 0.0; 792 _latest_cms_concurrent_sweeping_time_secs = 0.0; 793 _latest_cms_msc_end_to_msc_start_time_secs = 0.0; 794 _latest_cms_ms_end_to_ms_start = 0.0; 795 _latest_cms_remark_start_to_end_time_secs = 0.0; 796 _latest_cms_initial_mark_start_to_end_time_secs = 0.0; 797 _latest_cms_ms_marking_start_to_end_time_secs = 0.0; 798 } 799 800 void CMSAdaptiveSizePolicy::clear_generation_free_space_flags() { 801 AdaptiveSizePolicy::clear_generation_free_space_flags(); 802 803 set_change_young_gen_for_maj_pauses(0); 804 } 805 806 void CMSAdaptiveSizePolicy::concurrent_phases_resume() { 807 if (PrintAdaptiveSizePolicy && Verbose) { 808 gclog_or_tty->stamp(); 809 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::concurrent_phases_resume()"); 810 } 811 _concurrent_timer.start(); 812 } 813 814 double CMSAdaptiveSizePolicy::time_since_major_gc() const { 815 _concurrent_timer.stop(); 816 double time_since_cms_gc = _concurrent_timer.seconds(); 817 _concurrent_timer.start(); 818 _STW_timer.stop(); 819 double time_since_STW_gc = _STW_timer.seconds(); 820 _STW_timer.start(); 821 822 return MIN2(time_since_cms_gc, time_since_STW_gc); 823 } 824 825 double CMSAdaptiveSizePolicy::major_gc_interval_average_for_decay() const { 826 double cms_interval = _avg_concurrent_interval->average(); 827 double msc_interval = _avg_msc_interval->average(); 828 double ms_interval = _avg_ms_interval->average(); 829 830 return MAX3(cms_interval, msc_interval, ms_interval); 831 } 832 833 double CMSAdaptiveSizePolicy::cms_gc_cost() const { 834 return avg_major_gc_cost()->average(); 835 } 836 837 void CMSAdaptiveSizePolicy::ms_collection_marking_begin() { 838 _STW_timer.stop(); 839 // Start accumumlating time for the marking in the STW timer. 840 _STW_timer.reset(); 841 _STW_timer.start(); 842 } 843 844 void CMSAdaptiveSizePolicy::ms_collection_marking_end( 845 GCCause::Cause gc_cause) { 846 _STW_timer.stop(); 847 if (gc_cause != GCCause::_java_lang_system_gc || 848 UseAdaptiveSizePolicyWithSystemGC) { 849 _latest_cms_ms_marking_start_to_end_time_secs = _STW_timer.seconds(); 850 if (PrintAdaptiveSizePolicy && Verbose) { 851 gclog_or_tty->print_cr("CMSAdaptiveSizePolicy::" 852 "msc_collection_marking_end: mutator time %f", 853 _latest_cms_ms_marking_start_to_end_time_secs); 854 } 855 } 856 _STW_timer.reset(); 857 _STW_timer.start(); 858 } 859 860 double CMSAdaptiveSizePolicy::gc_cost() const { 861 double cms_gen_cost = cms_gc_cost(); 862 double result = MIN2(1.0, minor_gc_cost() + cms_gen_cost); 863 assert(result >= 0.0, "Both minor and major costs are non-negative"); 864 return result; 865 } 866 867 // Cost of collection (unit-less) 868 double CMSAdaptiveSizePolicy::collection_cost(double pause_in_seconds, 869 double interval_in_seconds) { 870 // Cost of collection (unit-less) 871 double cost = 0.0; 872 if ((interval_in_seconds > 0.0) && 873 (pause_in_seconds > 0.0)) { 874 cost = 875 pause_in_seconds / interval_in_seconds; 876 } 877 return cost; 878 } 879 880 size_t CMSAdaptiveSizePolicy::adjust_eden_for_pause_time(size_t cur_eden) { 881 size_t change = 0; 882 size_t desired_eden = cur_eden; 883 884 // reduce eden size 885 change = eden_decrement_aligned_down(cur_eden); 886 desired_eden = cur_eden - change; 887 888 if (PrintAdaptiveSizePolicy && Verbose) { 889 gclog_or_tty->print_cr( 890 "CMSAdaptiveSizePolicy::adjust_eden_for_pause_time " 891 "adjusting eden for pause time. " 892 " starting eden size " SIZE_FORMAT 893 " reduced eden size " SIZE_FORMAT 894 " eden delta " SIZE_FORMAT, 895 cur_eden, desired_eden, change); 896 } 897 898 return desired_eden; 899 } 900 901 size_t CMSAdaptiveSizePolicy::adjust_eden_for_throughput(size_t cur_eden) { 902 903 size_t desired_eden = cur_eden; 904 905 set_change_young_gen_for_throughput(increase_young_gen_for_througput_true); 906 907 size_t change = eden_increment_aligned_up(cur_eden); 908 size_t scaled_change = scale_by_gen_gc_cost(change, minor_gc_cost()); 909 910 if (cur_eden + scaled_change > cur_eden) { 911 desired_eden = cur_eden + scaled_change; 912 } 913 914 _young_gen_change_for_minor_throughput++; 915 916 if (PrintAdaptiveSizePolicy && Verbose) { 917 gclog_or_tty->print_cr( 918 "CMSAdaptiveSizePolicy::adjust_eden_for_throughput " 919 "adjusting eden for throughput. " 920 " starting eden size " SIZE_FORMAT 921 " increased eden size " SIZE_FORMAT 922 " eden delta " SIZE_FORMAT, 923 cur_eden, desired_eden, scaled_change); 924 } 925 926 return desired_eden; 927 } 928 929 size_t CMSAdaptiveSizePolicy::adjust_eden_for_footprint(size_t cur_eden) { 930 931 set_decrease_for_footprint(decrease_young_gen_for_footprint_true); 932 933 size_t change = eden_decrement(cur_eden); 934 size_t desired_eden_size = cur_eden - change; 935 936 if (PrintAdaptiveSizePolicy && Verbose) { 937 gclog_or_tty->print_cr( 938 "CMSAdaptiveSizePolicy::adjust_eden_for_footprint " 939 "adjusting eden for footprint. " 940 " starting eden size " SIZE_FORMAT 941 " reduced eden size " SIZE_FORMAT 942 " eden delta " SIZE_FORMAT, 943 cur_eden, desired_eden_size, change); 944 } 945 return desired_eden_size; 946 } 947 948 // The eden and promo versions should be combined if possible. 949 // They are the same except that the sizes of the decrement 950 // and increment are different for eden and promo. 951 size_t CMSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) { 952 size_t delta = eden_decrement(cur_eden); 953 return align_size_down(delta, generation_alignment()); 954 } 955 956 size_t CMSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) { 957 size_t delta = eden_increment(cur_eden); 958 return align_size_up(delta, generation_alignment()); 959 } 960 961 size_t CMSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) { 962 size_t delta = promo_decrement(cur_promo); 963 return align_size_down(delta, generation_alignment()); 964 } 965 966 size_t CMSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) { 967 size_t delta = promo_increment(cur_promo); 968 return align_size_up(delta, generation_alignment()); 969 } 970 971 972 void CMSAdaptiveSizePolicy::compute_eden_space_size(size_t cur_eden, 973 size_t max_eden_size) 974 { 975 size_t desired_eden_size = cur_eden; 976 size_t eden_limit = max_eden_size; 977 978 // Printout input 979 if (PrintGC && PrintAdaptiveSizePolicy) { 980 gclog_or_tty->print_cr( 981 "CMSAdaptiveSizePolicy::compute_eden_space_size: " 982 "cur_eden " SIZE_FORMAT, 983 cur_eden); 984 } 985 986 // Used for diagnostics 987 clear_generation_free_space_flags(); 988 989 if (_avg_minor_pause->padded_average() > gc_pause_goal_sec()) { 990 if (minor_pause_young_estimator()->decrement_will_decrease()) { 991 // If the minor pause is too long, shrink the young gen. 992 set_change_young_gen_for_min_pauses( 993 decrease_young_gen_for_min_pauses_true); 994 desired_eden_size = adjust_eden_for_pause_time(desired_eden_size); 995 } 996 } else if ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) || 997 (avg_initial_pause()->padded_average() > gc_pause_goal_sec())) { 998 // The remark or initial pauses are not meeting the goal. Should 999 // the generation be shrunk? 1000 if (get_and_clear_first_after_collection() && 1001 ((avg_remark_pause()->padded_average() > gc_pause_goal_sec() && 1002 remark_pause_young_estimator()->decrement_will_decrease()) || 1003 (avg_initial_pause()->padded_average() > gc_pause_goal_sec() && 1004 initial_pause_young_estimator()->decrement_will_decrease()))) { 1005 1006 set_change_young_gen_for_maj_pauses( 1007 decrease_young_gen_for_maj_pauses_true); 1008 1009 // If the remark or initial pause is too long and this is the 1010 // first young gen collection after a cms collection, shrink 1011 // the young gen. 1012 desired_eden_size = adjust_eden_for_pause_time(desired_eden_size); 1013 } 1014 // If not the first young gen collection after a cms collection, 1015 // don't do anything. In this case an adjustment has already 1016 // been made and the results of the adjustment has not yet been 1017 // measured. 1018 } else if ((minor_gc_cost() >= 0.0) && 1019 (adjusted_mutator_cost() < _throughput_goal)) { 1020 desired_eden_size = adjust_eden_for_throughput(desired_eden_size); 1021 } else { 1022 desired_eden_size = adjust_eden_for_footprint(desired_eden_size); 1023 } 1024 1025 if (PrintGC && PrintAdaptiveSizePolicy) { 1026 gclog_or_tty->print_cr( 1027 "CMSAdaptiveSizePolicy::compute_eden_space_size limits:" 1028 " desired_eden_size: " SIZE_FORMAT 1029 " old_eden_size: " SIZE_FORMAT, 1030 desired_eden_size, cur_eden); 1031 } 1032 1033 set_eden_size(desired_eden_size); 1034 } 1035 1036 size_t CMSAdaptiveSizePolicy::adjust_promo_for_pause_time(size_t cur_promo) { 1037 size_t change = 0; 1038 size_t desired_promo = cur_promo; 1039 // Move this test up to caller like the adjust_eden_for_pause_time() 1040 // call. 1041 if ((AdaptiveSizePausePolicy == 0) && 1042 ((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) || 1043 (avg_initial_pause()->padded_average() > gc_pause_goal_sec()))) { 1044 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true); 1045 change = promo_decrement_aligned_down(cur_promo); 1046 desired_promo = cur_promo - change; 1047 } else if ((AdaptiveSizePausePolicy > 0) && 1048 (((avg_remark_pause()->padded_average() > gc_pause_goal_sec()) && 1049 remark_pause_old_estimator()->decrement_will_decrease()) || 1050 ((avg_initial_pause()->padded_average() > gc_pause_goal_sec()) && 1051 initial_pause_old_estimator()->decrement_will_decrease()))) { 1052 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true); 1053 change = promo_decrement_aligned_down(cur_promo); 1054 desired_promo = cur_promo - change; 1055 } 1056 1057 if ((change != 0) &&PrintAdaptiveSizePolicy && Verbose) { 1058 gclog_or_tty->print_cr( 1059 "CMSAdaptiveSizePolicy::adjust_promo_for_pause_time " 1060 "adjusting promo for pause time. " 1061 " starting promo size " SIZE_FORMAT 1062 " reduced promo size " SIZE_FORMAT 1063 " promo delta " SIZE_FORMAT, 1064 cur_promo, desired_promo, change); 1065 } 1066 1067 return desired_promo; 1068 } 1069 1070 // Try to share this with PS. 1071 size_t CMSAdaptiveSizePolicy::scale_by_gen_gc_cost(size_t base_change, 1072 double gen_gc_cost) { 1073 1074 // Calculate the change to use for the tenured gen. 1075 size_t scaled_change = 0; 1076 // Can the increment to the generation be scaled? 1077 if (gc_cost() >= 0.0 && gen_gc_cost >= 0.0) { 1078 double scale_by_ratio = gen_gc_cost / gc_cost(); 1079 scaled_change = 1080 (size_t) (scale_by_ratio * (double) base_change); 1081 if (PrintAdaptiveSizePolicy && Verbose) { 1082 gclog_or_tty->print_cr( 1083 "Scaled tenured increment: " SIZE_FORMAT " by %f down to " 1084 SIZE_FORMAT, 1085 base_change, scale_by_ratio, scaled_change); 1086 } 1087 } else if (gen_gc_cost >= 0.0) { 1088 // Scaling is not going to work. If the major gc time is the 1089 // larger than the other GC costs, give it a full increment. 1090 if (gen_gc_cost >= (gc_cost() - gen_gc_cost)) { 1091 scaled_change = base_change; 1092 } 1093 } else { 1094 // Don't expect to get here but it's ok if it does 1095 // in the product build since the delta will be 0 1096 // and nothing will change. 1097 assert(false, "Unexpected value for gc costs"); 1098 } 1099 1100 return scaled_change; 1101 } 1102 1103 size_t CMSAdaptiveSizePolicy::adjust_promo_for_throughput(size_t cur_promo) { 1104 1105 size_t desired_promo = cur_promo; 1106 1107 set_change_old_gen_for_throughput(increase_old_gen_for_throughput_true); 1108 1109 size_t change = promo_increment_aligned_up(cur_promo); 1110 size_t scaled_change = scale_by_gen_gc_cost(change, major_gc_cost()); 1111 1112 if (cur_promo + scaled_change > cur_promo) { 1113 desired_promo = cur_promo + scaled_change; 1114 } 1115 1116 _old_gen_change_for_major_throughput++; 1117 1118 if (PrintAdaptiveSizePolicy && Verbose) { 1119 gclog_or_tty->print_cr( 1120 "CMSAdaptiveSizePolicy::adjust_promo_for_throughput " 1121 "adjusting promo for throughput. " 1122 " starting promo size " SIZE_FORMAT 1123 " increased promo size " SIZE_FORMAT 1124 " promo delta " SIZE_FORMAT, 1125 cur_promo, desired_promo, scaled_change); 1126 } 1127 1128 return desired_promo; 1129 } 1130 1131 size_t CMSAdaptiveSizePolicy::adjust_promo_for_footprint(size_t cur_promo, 1132 size_t cur_eden) { 1133 1134 set_decrease_for_footprint(decrease_young_gen_for_footprint_true); 1135 1136 size_t change = promo_decrement(cur_promo); 1137 size_t desired_promo_size = cur_promo - change; 1138 1139 if (PrintAdaptiveSizePolicy && Verbose) { 1140 gclog_or_tty->print_cr( 1141 "CMSAdaptiveSizePolicy::adjust_promo_for_footprint " 1142 "adjusting promo for footprint. " 1143 " starting promo size " SIZE_FORMAT 1144 " reduced promo size " SIZE_FORMAT 1145 " promo delta " SIZE_FORMAT, 1146 cur_promo, desired_promo_size, change); 1147 } 1148 return desired_promo_size; 1149 } 1150 1151 void CMSAdaptiveSizePolicy::compute_tenured_generation_free_space( 1152 size_t cur_tenured_free, 1153 size_t max_tenured_available, 1154 size_t cur_eden) { 1155 // This can be bad if the desired value grows/shrinks without 1156 // any connection to the read free space 1157 size_t desired_promo_size = promo_size(); 1158 size_t tenured_limit = max_tenured_available; 1159 1160 // Printout input 1161 if (PrintGC && PrintAdaptiveSizePolicy) { 1162 gclog_or_tty->print_cr( 1163 "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space: " 1164 "cur_tenured_free " SIZE_FORMAT 1165 " max_tenured_available " SIZE_FORMAT, 1166 cur_tenured_free, max_tenured_available); 1167 } 1168 1169 // Used for diagnostics 1170 clear_generation_free_space_flags(); 1171 1172 set_decide_at_full_gc(decide_at_full_gc_true); 1173 if (avg_remark_pause()->padded_average() > gc_pause_goal_sec() || 1174 avg_initial_pause()->padded_average() > gc_pause_goal_sec()) { 1175 desired_promo_size = adjust_promo_for_pause_time(cur_tenured_free); 1176 } else if (avg_minor_pause()->padded_average() > gc_pause_goal_sec()) { 1177 // Nothing to do since the minor collections are too large and 1178 // this method only deals with the cms generation. 1179 } else if ((cms_gc_cost() >= 0.0) && 1180 (adjusted_mutator_cost() < _throughput_goal)) { 1181 desired_promo_size = adjust_promo_for_throughput(cur_tenured_free); 1182 } else { 1183 desired_promo_size = adjust_promo_for_footprint(cur_tenured_free, 1184 cur_eden); 1185 } 1186 1187 if (PrintGC && PrintAdaptiveSizePolicy) { 1188 gclog_or_tty->print_cr( 1189 "CMSAdaptiveSizePolicy::compute_tenured_generation_free_space limits:" 1190 " desired_promo_size: " SIZE_FORMAT 1191 " old_promo_size: " SIZE_FORMAT, 1192 desired_promo_size, cur_tenured_free); 1193 } 1194 1195 set_promo_size(desired_promo_size); 1196 } 1197 1198 uint CMSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold( 1199 bool is_survivor_overflow, 1200 uint tenuring_threshold, 1201 size_t survivor_limit) { 1202 assert(survivor_limit >= generation_alignment(), 1203 "survivor_limit too small"); 1204 assert((size_t)align_size_down(survivor_limit, generation_alignment()) 1205 == survivor_limit, "survivor_limit not aligned"); 1206 1207 // Change UsePSAdaptiveSurvivorSizePolicy -> UseAdaptiveSurvivorSizePolicy? 1208 if (!UsePSAdaptiveSurvivorSizePolicy || 1209 !young_gen_policy_is_ready()) { 1210 return tenuring_threshold; 1211 } 1212 1213 // We'll decide whether to increase or decrease the tenuring 1214 // threshold based partly on the newly computed survivor size 1215 // (if we hit the maximum limit allowed, we'll always choose to 1216 // decrement the threshold). 1217 bool incr_tenuring_threshold = false; 1218 bool decr_tenuring_threshold = false; 1219 1220 set_decrement_tenuring_threshold_for_gc_cost(false); 1221 set_increment_tenuring_threshold_for_gc_cost(false); 1222 set_decrement_tenuring_threshold_for_survivor_limit(false); 1223 1224 if (!is_survivor_overflow) { 1225 // Keep running averages on how much survived 1226 1227 // We use the tenuring threshold to equalize the cost of major 1228 // and minor collections. 1229 // ThresholdTolerance is used to indicate how sensitive the 1230 // tenuring threshold is to differences in cost betweent the 1231 // collection types. 1232 1233 // Get the times of interest. This involves a little work, so 1234 // we cache the values here. 1235 const double major_cost = major_gc_cost(); 1236 const double minor_cost = minor_gc_cost(); 1237 1238 if (minor_cost > major_cost * _threshold_tolerance_percent) { 1239 // Minor times are getting too long; lower the threshold so 1240 // less survives and more is promoted. 1241 decr_tenuring_threshold = true; 1242 set_decrement_tenuring_threshold_for_gc_cost(true); 1243 } else if (major_cost > minor_cost * _threshold_tolerance_percent) { 1244 // Major times are too long, so we want less promotion. 1245 incr_tenuring_threshold = true; 1246 set_increment_tenuring_threshold_for_gc_cost(true); 1247 } 1248 1249 } else { 1250 // Survivor space overflow occurred, so promoted and survived are 1251 // not accurate. We'll make our best guess by combining survived 1252 // and promoted and count them as survivors. 1253 // 1254 // We'll lower the tenuring threshold to see if we can correct 1255 // things. Also, set the survivor size conservatively. We're 1256 // trying to avoid many overflows from occurring if defnew size 1257 // is just too small. 1258 1259 decr_tenuring_threshold = true; 1260 } 1261 1262 // The padded average also maintains a deviation from the average; 1263 // we use this to see how good of an estimate we have of what survived. 1264 // We're trying to pad the survivor size as little as possible without 1265 // overflowing the survivor spaces. 1266 size_t target_size = align_size_up((size_t)_avg_survived->padded_average(), 1267 generation_alignment()); 1268 target_size = MAX2(target_size, generation_alignment()); 1269 1270 if (target_size > survivor_limit) { 1271 // Target size is bigger than we can handle. Let's also reduce 1272 // the tenuring threshold. 1273 target_size = survivor_limit; 1274 decr_tenuring_threshold = true; 1275 set_decrement_tenuring_threshold_for_survivor_limit(true); 1276 } 1277 1278 // Finally, increment or decrement the tenuring threshold, as decided above. 1279 // We test for decrementing first, as we might have hit the target size 1280 // limit. 1281 if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { 1282 if (tenuring_threshold > 1) { 1283 tenuring_threshold--; 1284 } 1285 } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { 1286 if (tenuring_threshold < MaxTenuringThreshold) { 1287 tenuring_threshold++; 1288 } 1289 } 1290 1291 // We keep a running average of the amount promoted which is used 1292 // to decide when we should collect the old generation (when 1293 // the amount of old gen free space is less than what we expect to 1294 // promote). 1295 1296 if (PrintAdaptiveSizePolicy) { 1297 // A little more detail if Verbose is on 1298 GenCollectedHeap* gch = GenCollectedHeap::heap(); 1299 if (Verbose) { 1300 gclog_or_tty->print( " avg_survived: %f" 1301 " avg_deviation: %f", 1302 _avg_survived->average(), 1303 _avg_survived->deviation()); 1304 } 1305 1306 gclog_or_tty->print( " avg_survived_padded_avg: %f", 1307 _avg_survived->padded_average()); 1308 1309 if (Verbose) { 1310 gclog_or_tty->print( " avg_promoted_avg: %f" 1311 " avg_promoted_dev: %f", 1312 gch->gc_stats(1)->avg_promoted()->average(), 1313 gch->gc_stats(1)->avg_promoted()->deviation()); 1314 } 1315 1316 gclog_or_tty->print( " avg_promoted_padded_avg: %f" 1317 " avg_pretenured_padded_avg: %f" 1318 " tenuring_thresh: %u" 1319 " target_size: " SIZE_FORMAT 1320 " survivor_limit: " SIZE_FORMAT, 1321 gch->gc_stats(1)->avg_promoted()->padded_average(), 1322 _avg_pretenured->padded_average(), 1323 tenuring_threshold, target_size, survivor_limit); 1324 gclog_or_tty->cr(); 1325 } 1326 1327 set_survivor_size(target_size); 1328 1329 return tenuring_threshold; 1330 } 1331 1332 bool CMSAdaptiveSizePolicy::get_and_clear_first_after_collection() { 1333 bool result = _first_after_collection; 1334 _first_after_collection = false; 1335 return result; 1336 } 1337 1338 bool CMSAdaptiveSizePolicy::print_adaptive_size_policy_on( 1339 outputStream* st) const { 1340 1341 if (!UseAdaptiveSizePolicy) return false; 1342 1343 GenCollectedHeap* gch = GenCollectedHeap::heap(); 1344 Generation* gen0 = gch->get_gen(0); 1345 DefNewGeneration* def_new = gen0->as_DefNewGeneration(); 1346 return 1347 AdaptiveSizePolicy::print_adaptive_size_policy_on( 1348 st, 1349 def_new->tenuring_threshold()); 1350 }