Mercurial > hg > graal-compiler
annotate src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp @ 1552:c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
Summary: Change all the Sun copyrights to Oracle copyright
Reviewed-by: ohair
| author | trims |
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| date | Thu, 27 May 2010 19:08:38 -0700 |
| parents | 0bfd3fb24150 |
| children | f95d63e2154a |
| rev | line source |
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| 0 | 1 /* |
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2 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 25 #include "incls/_precompiled.incl" | |
| 26 #include "incls/_psAdaptiveSizePolicy.cpp.incl" | |
| 27 | |
| 28 #include <math.h> | |
| 29 | |
| 30 PSAdaptiveSizePolicy::PSAdaptiveSizePolicy(size_t init_eden_size, | |
| 31 size_t init_promo_size, | |
| 32 size_t init_survivor_size, | |
| 33 size_t intra_generation_alignment, | |
| 34 double gc_pause_goal_sec, | |
| 35 double gc_minor_pause_goal_sec, | |
| 36 uint gc_cost_ratio) : | |
| 37 AdaptiveSizePolicy(init_eden_size, | |
| 38 init_promo_size, | |
| 39 init_survivor_size, | |
| 40 gc_pause_goal_sec, | |
| 41 gc_cost_ratio), | |
| 42 _collection_cost_margin_fraction(AdaptiveSizePolicyCollectionCostMargin/ | |
| 43 100.0), | |
| 44 _intra_generation_alignment(intra_generation_alignment), | |
| 45 _live_at_last_full_gc(init_promo_size), | |
| 46 _gc_minor_pause_goal_sec(gc_minor_pause_goal_sec), | |
| 47 _latest_major_mutator_interval_seconds(0), | |
| 48 _young_gen_change_for_major_pause_count(0) | |
| 49 { | |
| 50 // Sizing policy statistics | |
| 51 _avg_major_pause = | |
| 52 new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding); | |
| 53 _avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); | |
| 54 _avg_major_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); | |
| 55 | |
| 56 _avg_base_footprint = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight); | |
| 57 _major_pause_old_estimator = | |
| 58 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); | |
| 59 _major_pause_young_estimator = | |
| 60 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); | |
| 61 _major_collection_estimator = | |
| 62 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); | |
| 63 | |
| 64 _young_gen_size_increment_supplement = YoungGenerationSizeSupplement; | |
| 65 _old_gen_size_increment_supplement = TenuredGenerationSizeSupplement; | |
| 66 | |
| 67 // Start the timers | |
| 68 _major_timer.start(); | |
| 69 | |
| 70 _old_gen_policy_is_ready = false; | |
| 71 } | |
| 72 | |
| 73 void PSAdaptiveSizePolicy::major_collection_begin() { | |
| 74 // Update the interval time | |
| 75 _major_timer.stop(); | |
| 76 // Save most recent collection time | |
| 77 _latest_major_mutator_interval_seconds = _major_timer.seconds(); | |
| 78 _major_timer.reset(); | |
| 79 _major_timer.start(); | |
| 80 } | |
| 81 | |
| 82 void PSAdaptiveSizePolicy::update_minor_pause_old_estimator( | |
| 83 double minor_pause_in_ms) { | |
| 84 double promo_size_in_mbytes = ((double)_promo_size)/((double)M); | |
| 85 _minor_pause_old_estimator->update(promo_size_in_mbytes, | |
| 86 minor_pause_in_ms); | |
| 87 } | |
| 88 | |
| 89 void PSAdaptiveSizePolicy::major_collection_end(size_t amount_live, | |
| 90 GCCause::Cause gc_cause) { | |
| 91 // Update the pause time. | |
| 92 _major_timer.stop(); | |
| 93 | |
| 94 if (gc_cause != GCCause::_java_lang_system_gc || | |
| 95 UseAdaptiveSizePolicyWithSystemGC) { | |
| 96 double major_pause_in_seconds = _major_timer.seconds(); | |
| 97 double major_pause_in_ms = major_pause_in_seconds * MILLIUNITS; | |
| 98 | |
| 99 // Sample for performance counter | |
| 100 _avg_major_pause->sample(major_pause_in_seconds); | |
| 101 | |
| 102 // Cost of collection (unit-less) | |
| 103 double collection_cost = 0.0; | |
| 104 if ((_latest_major_mutator_interval_seconds > 0.0) && | |
| 105 (major_pause_in_seconds > 0.0)) { | |
| 106 double interval_in_seconds = | |
| 107 _latest_major_mutator_interval_seconds + major_pause_in_seconds; | |
| 108 collection_cost = | |
| 109 major_pause_in_seconds / interval_in_seconds; | |
| 110 avg_major_gc_cost()->sample(collection_cost); | |
| 111 | |
| 112 // Sample for performance counter | |
| 113 _avg_major_interval->sample(interval_in_seconds); | |
| 114 } | |
| 115 | |
| 116 // Calculate variables used to estimate pause time vs. gen sizes | |
| 117 double eden_size_in_mbytes = ((double)_eden_size)/((double)M); | |
| 118 double promo_size_in_mbytes = ((double)_promo_size)/((double)M); | |
| 119 _major_pause_old_estimator->update(promo_size_in_mbytes, | |
| 120 major_pause_in_ms); | |
| 121 _major_pause_young_estimator->update(eden_size_in_mbytes, | |
| 122 major_pause_in_ms); | |
| 123 | |
| 124 if (PrintAdaptiveSizePolicy && Verbose) { | |
| 125 gclog_or_tty->print("psAdaptiveSizePolicy::major_collection_end: " | |
| 126 "major gc cost: %f average: %f", collection_cost, | |
| 127 avg_major_gc_cost()->average()); | |
| 128 gclog_or_tty->print_cr(" major pause: %f major period %f", | |
| 129 major_pause_in_ms, | |
| 130 _latest_major_mutator_interval_seconds * MILLIUNITS); | |
| 131 } | |
| 132 | |
| 133 // Calculate variable used to estimate collection cost vs. gen sizes | |
| 134 assert(collection_cost >= 0.0, "Expected to be non-negative"); | |
| 135 _major_collection_estimator->update(promo_size_in_mbytes, | |
| 136 collection_cost); | |
| 137 } | |
| 138 | |
| 139 // Update the amount live at the end of a full GC | |
| 140 _live_at_last_full_gc = amount_live; | |
| 141 | |
| 142 // The policy does not have enough data until at least some major collections | |
| 143 // have been done. | |
| 144 if (_avg_major_pause->count() >= AdaptiveSizePolicyReadyThreshold) { | |
| 145 _old_gen_policy_is_ready = true; | |
| 146 } | |
| 147 | |
| 148 // Interval times use this timer to measure the interval that | |
| 149 // the mutator runs. Reset after the GC pause has been measured. | |
| 150 _major_timer.reset(); | |
| 151 _major_timer.start(); | |
| 152 } | |
| 153 | |
| 154 // If the remaining free space in the old generation is less that | |
| 155 // that expected to be needed by the next collection, do a full | |
| 156 // collection now. | |
| 157 bool PSAdaptiveSizePolicy::should_full_GC(size_t old_free_in_bytes) { | |
| 158 | |
| 159 // A similar test is done in the scavenge's should_attempt_scavenge(). If | |
| 160 // this is changed, decide if that test should also be changed. | |
| 161 bool result = padded_average_promoted_in_bytes() > (float) old_free_in_bytes; | |
| 162 if (PrintGCDetails && Verbose) { | |
| 163 if (result) { | |
| 164 gclog_or_tty->print(" full after scavenge: "); | |
| 165 } else { | |
| 166 gclog_or_tty->print(" no full after scavenge: "); | |
| 167 } | |
| 168 gclog_or_tty->print_cr(" average_promoted " SIZE_FORMAT | |
| 169 " padded_average_promoted " SIZE_FORMAT | |
| 170 " free in old gen " SIZE_FORMAT, | |
| 171 (size_t) average_promoted_in_bytes(), | |
| 172 (size_t) padded_average_promoted_in_bytes(), | |
| 173 old_free_in_bytes); | |
| 174 } | |
| 175 return result; | |
| 176 } | |
| 177 | |
| 178 void PSAdaptiveSizePolicy::clear_generation_free_space_flags() { | |
| 179 | |
| 180 AdaptiveSizePolicy::clear_generation_free_space_flags(); | |
| 181 | |
| 182 set_change_old_gen_for_min_pauses(0); | |
| 183 | |
| 184 set_change_young_gen_for_maj_pauses(0); | |
| 185 } | |
| 186 | |
| 187 // If this is not a full GC, only test and modify the young generation. | |
| 188 | |
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189 void PSAdaptiveSizePolicy::compute_generation_free_space( |
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190 size_t young_live, |
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191 size_t eden_live, |
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192 size_t old_live, |
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193 size_t perm_live, |
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194 size_t cur_eden, |
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195 size_t max_old_gen_size, |
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196 size_t max_eden_size, |
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197 bool is_full_gc, |
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198 GCCause::Cause gc_cause, |
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199 CollectorPolicy* collector_policy) { |
| 0 | 200 |
| 201 // Update statistics | |
| 202 // Time statistics are updated as we go, update footprint stats here | |
| 203 _avg_base_footprint->sample(BaseFootPrintEstimate + perm_live); | |
| 204 avg_young_live()->sample(young_live); | |
| 205 avg_eden_live()->sample(eden_live); | |
| 206 if (is_full_gc) { | |
| 207 // old_live is only accurate after a full gc | |
| 208 avg_old_live()->sample(old_live); | |
| 209 } | |
| 210 | |
| 211 // This code used to return if the policy was not ready , i.e., | |
| 212 // policy_is_ready() returning false. The intent was that | |
| 213 // decisions below needed major collection times and so could | |
| 214 // not be made before two major collections. A consequence was | |
| 215 // adjustments to the young generation were not done until after | |
| 216 // two major collections even if the minor collections times | |
| 217 // exceeded the requested goals. Now let the young generation | |
| 218 // adjust for the minor collection times. Major collection times | |
| 219 // will be zero for the first collection and will naturally be | |
| 220 // ignored. Tenured generation adjustments are only made at the | |
| 221 // full collections so until the second major collection has | |
| 222 // been reached, no tenured generation adjustments will be made. | |
| 223 | |
| 224 // Until we know better, desired promotion size uses the last calculation | |
| 225 size_t desired_promo_size = _promo_size; | |
| 226 | |
| 227 // Start eden at the current value. The desired value that is stored | |
| 228 // in _eden_size is not bounded by constraints of the heap and can | |
| 229 // run away. | |
| 230 // | |
| 231 // As expected setting desired_eden_size to the current | |
| 232 // value of desired_eden_size as a starting point | |
| 233 // caused desired_eden_size to grow way too large and caused | |
| 234 // an overflow down stream. It may have improved performance in | |
| 235 // some case but is dangerous. | |
| 236 size_t desired_eden_size = cur_eden; | |
| 237 | |
| 238 #ifdef ASSERT | |
| 239 size_t original_promo_size = desired_promo_size; | |
| 240 size_t original_eden_size = desired_eden_size; | |
| 241 #endif | |
| 242 | |
| 243 // Cache some values. There's a bit of work getting these, so | |
| 244 // we might save a little time. | |
| 245 const double major_cost = major_gc_cost(); | |
| 246 const double minor_cost = minor_gc_cost(); | |
| 247 | |
| 248 // Used for diagnostics | |
| 249 clear_generation_free_space_flags(); | |
| 250 | |
| 251 // Limits on our growth | |
| 252 size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average()); | |
| 253 | |
| 254 // This method sets the desired eden size. That plus the | |
| 255 // desired survivor space sizes sets the desired young generation | |
| 256 // size. This methods does not know what the desired survivor | |
| 257 // size is but expects that other policy will attempt to make | |
| 258 // the survivor sizes compatible with the live data in the | |
| 259 // young generation. This limit is an estimate of the space left | |
| 260 // in the young generation after the survivor spaces have been | |
| 261 // subtracted out. | |
| 262 size_t eden_limit = max_eden_size; | |
| 263 | |
| 264 // But don't force a promo size below the current promo size. Otherwise, | |
| 265 // the promo size will shrink for no good reason. | |
| 266 promo_limit = MAX2(promo_limit, _promo_size); | |
| 267 | |
| 268 const double gc_cost_limit = GCTimeLimit/100.0; | |
| 269 | |
| 270 // Which way should we go? | |
| 271 // if pause requirement is not met | |
| 272 // adjust size of any generation with average paus exceeding | |
| 273 // the pause limit. Adjust one pause at a time (the larger) | |
| 274 // and only make adjustments for the major pause at full collections. | |
| 275 // else if throughput requirement not met | |
| 276 // adjust the size of the generation with larger gc time. Only | |
| 277 // adjust one generation at a time. | |
| 278 // else | |
| 279 // adjust down the total heap size. Adjust down the larger of the | |
| 280 // generations. | |
| 281 | |
| 282 // Add some checks for a threshhold for a change. For example, | |
| 283 // a change less than the necessary alignment is probably not worth | |
| 284 // attempting. | |
| 285 | |
| 286 | |
| 287 if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) || | |
| 288 (_avg_major_pause->padded_average() > gc_pause_goal_sec())) { | |
| 289 // | |
| 290 // Check pauses | |
| 291 // | |
| 292 // Make changes only to affect one of the pauses (the larger) | |
| 293 // at a time. | |
| 294 adjust_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size); | |
| 295 | |
| 296 } else if (_avg_minor_pause->padded_average() > gc_minor_pause_goal_sec()) { | |
| 297 // Adjust only for the minor pause time goal | |
| 298 adjust_for_minor_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size); | |
| 299 | |
| 300 } else if(adjusted_mutator_cost() < _throughput_goal) { | |
| 301 // This branch used to require that (mutator_cost() > 0.0 in 1.4.2. | |
| 302 // This sometimes resulted in skipping to the minimize footprint | |
| 303 // code. Change this to try and reduce GC time if mutator time is | |
| 304 // negative for whatever reason. Or for future consideration, | |
| 305 // bail out of the code if mutator time is negative. | |
| 306 // | |
| 307 // Throughput | |
| 308 // | |
| 309 assert(major_cost >= 0.0, "major cost is < 0.0"); | |
| 310 assert(minor_cost >= 0.0, "minor cost is < 0.0"); | |
| 311 // Try to reduce the GC times. | |
| 312 adjust_for_throughput(is_full_gc, &desired_promo_size, &desired_eden_size); | |
| 313 | |
| 314 } else { | |
| 315 | |
| 316 // Be conservative about reducing the footprint. | |
| 317 // Do a minimum number of major collections first. | |
| 318 // Have reasonable averages for major and minor collections costs. | |
| 319 if (UseAdaptiveSizePolicyFootprintGoal && | |
| 320 young_gen_policy_is_ready() && | |
| 321 avg_major_gc_cost()->average() >= 0.0 && | |
| 322 avg_minor_gc_cost()->average() >= 0.0) { | |
| 323 size_t desired_sum = desired_eden_size + desired_promo_size; | |
| 324 desired_eden_size = adjust_eden_for_footprint(desired_eden_size, | |
| 325 desired_sum); | |
| 326 if (is_full_gc) { | |
| 327 set_decide_at_full_gc(decide_at_full_gc_true); | |
| 328 desired_promo_size = adjust_promo_for_footprint(desired_promo_size, | |
| 329 desired_sum); | |
| 330 } | |
| 331 } | |
| 332 } | |
| 333 | |
| 334 // Note we make the same tests as in the code block below; the code | |
| 335 // seems a little easier to read with the printing in another block. | |
| 336 if (PrintAdaptiveSizePolicy) { | |
| 337 if (desired_promo_size > promo_limit) { | |
| 338 // "free_in_old_gen" was the original value for used for promo_limit | |
| 339 size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average()); | |
| 340 gclog_or_tty->print_cr( | |
| 341 "PSAdaptiveSizePolicy::compute_generation_free_space limits:" | |
| 342 " desired_promo_size: " SIZE_FORMAT | |
| 343 " promo_limit: " SIZE_FORMAT | |
| 344 " free_in_old_gen: " SIZE_FORMAT | |
| 345 " max_old_gen_size: " SIZE_FORMAT | |
| 346 " avg_old_live: " SIZE_FORMAT, | |
| 347 desired_promo_size, promo_limit, free_in_old_gen, | |
| 348 max_old_gen_size, (size_t) avg_old_live()->average()); | |
| 349 } | |
| 350 if (desired_eden_size > eden_limit) { | |
| 351 gclog_or_tty->print_cr( | |
| 352 "AdaptiveSizePolicy::compute_generation_free_space limits:" | |
| 353 " desired_eden_size: " SIZE_FORMAT | |
| 354 " old_eden_size: " SIZE_FORMAT | |
| 355 " eden_limit: " SIZE_FORMAT | |
| 356 " cur_eden: " SIZE_FORMAT | |
| 357 " max_eden_size: " SIZE_FORMAT | |
| 358 " avg_young_live: " SIZE_FORMAT, | |
| 359 desired_eden_size, _eden_size, eden_limit, cur_eden, | |
| 360 max_eden_size, (size_t)avg_young_live()->average()); | |
| 361 } | |
| 362 if (gc_cost() > gc_cost_limit) { | |
| 363 gclog_or_tty->print_cr( | |
| 364 "AdaptiveSizePolicy::compute_generation_free_space: gc time limit" | |
| 365 " gc_cost: %f " | |
| 366 " GCTimeLimit: %d", | |
| 367 gc_cost(), GCTimeLimit); | |
| 368 } | |
| 369 } | |
| 370 | |
| 371 // Align everything and make a final limit check | |
| 372 const size_t alignment = _intra_generation_alignment; | |
| 373 desired_eden_size = align_size_up(desired_eden_size, alignment); | |
| 374 desired_eden_size = MAX2(desired_eden_size, alignment); | |
| 375 desired_promo_size = align_size_up(desired_promo_size, alignment); | |
| 376 desired_promo_size = MAX2(desired_promo_size, alignment); | |
| 377 | |
| 378 eden_limit = align_size_down(eden_limit, alignment); | |
| 379 promo_limit = align_size_down(promo_limit, alignment); | |
| 380 | |
| 381 // Is too much time being spent in GC? | |
| 382 // Is the heap trying to grow beyond it's limits? | |
| 383 | |
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384 const size_t free_in_old_gen = |
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385 (size_t)(max_old_gen_size - avg_old_live()->average()); |
| 0 | 386 if (desired_promo_size > free_in_old_gen && desired_eden_size > eden_limit) { |
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387 check_gc_overhead_limit(young_live, |
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388 eden_live, |
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389 max_old_gen_size, |
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390 max_eden_size, |
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391 is_full_gc, |
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392 gc_cause, |
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393 collector_policy); |
| 0 | 394 } |
| 395 | |
| 396 | |
| 397 // And one last limit check, now that we've aligned things. | |
| 398 if (desired_eden_size > eden_limit) { | |
| 399 // If the policy says to get a larger eden but | |
| 400 // is hitting the limit, don't decrease eden. | |
| 401 // This can lead to a general drifting down of the | |
| 402 // eden size. Let the tenuring calculation push more | |
| 403 // into the old gen. | |
| 404 desired_eden_size = MAX2(eden_limit, cur_eden); | |
| 405 } | |
| 406 desired_promo_size = MIN2(desired_promo_size, promo_limit); | |
| 407 | |
| 408 | |
| 409 if (PrintAdaptiveSizePolicy) { | |
| 410 // Timing stats | |
| 411 gclog_or_tty->print( | |
| 412 "PSAdaptiveSizePolicy::compute_generation_free_space: costs" | |
| 413 " minor_time: %f" | |
| 414 " major_cost: %f" | |
| 415 " mutator_cost: %f" | |
| 416 " throughput_goal: %f", | |
| 417 minor_gc_cost(), major_gc_cost(), mutator_cost(), | |
| 418 _throughput_goal); | |
| 419 | |
| 420 // We give more details if Verbose is set | |
| 421 if (Verbose) { | |
| 422 gclog_or_tty->print( " minor_pause: %f" | |
| 423 " major_pause: %f" | |
| 424 " minor_interval: %f" | |
| 425 " major_interval: %f" | |
| 426 " pause_goal: %f", | |
| 427 _avg_minor_pause->padded_average(), | |
| 428 _avg_major_pause->padded_average(), | |
| 429 _avg_minor_interval->average(), | |
| 430 _avg_major_interval->average(), | |
| 431 gc_pause_goal_sec()); | |
| 432 } | |
| 433 | |
| 434 // Footprint stats | |
| 435 gclog_or_tty->print( " live_space: " SIZE_FORMAT | |
| 436 " free_space: " SIZE_FORMAT, | |
| 437 live_space(), free_space()); | |
| 438 // More detail | |
| 439 if (Verbose) { | |
| 440 gclog_or_tty->print( " base_footprint: " SIZE_FORMAT | |
| 441 " avg_young_live: " SIZE_FORMAT | |
| 442 " avg_old_live: " SIZE_FORMAT, | |
| 443 (size_t)_avg_base_footprint->average(), | |
| 444 (size_t)avg_young_live()->average(), | |
| 445 (size_t)avg_old_live()->average()); | |
| 446 } | |
| 447 | |
| 448 // And finally, our old and new sizes. | |
| 449 gclog_or_tty->print(" old_promo_size: " SIZE_FORMAT | |
| 450 " old_eden_size: " SIZE_FORMAT | |
| 451 " desired_promo_size: " SIZE_FORMAT | |
| 452 " desired_eden_size: " SIZE_FORMAT, | |
| 453 _promo_size, _eden_size, | |
| 454 desired_promo_size, desired_eden_size); | |
| 455 gclog_or_tty->cr(); | |
| 456 } | |
| 457 | |
| 458 decay_supplemental_growth(is_full_gc); | |
| 459 | |
| 460 set_promo_size(desired_promo_size); | |
| 461 set_eden_size(desired_eden_size); | |
| 462 }; | |
| 463 | |
| 464 void PSAdaptiveSizePolicy::decay_supplemental_growth(bool is_full_gc) { | |
| 465 // Decay the supplemental increment? Decay the supplement growth | |
| 466 // factor even if it is not used. It is only meant to give a boost | |
| 467 // to the initial growth and if it is not used, then it was not | |
| 468 // needed. | |
| 469 if (is_full_gc) { | |
| 470 // Don't wait for the threshold value for the major collections. If | |
| 471 // here, the supplemental growth term was used and should decay. | |
| 472 if ((_avg_major_pause->count() % TenuredGenerationSizeSupplementDecay) | |
| 473 == 0) { | |
| 474 _old_gen_size_increment_supplement = | |
| 475 _old_gen_size_increment_supplement >> 1; | |
| 476 } | |
| 477 } else { | |
| 478 if ((_avg_minor_pause->count() >= AdaptiveSizePolicyReadyThreshold) && | |
| 479 (_avg_minor_pause->count() % YoungGenerationSizeSupplementDecay) == 0) { | |
| 480 _young_gen_size_increment_supplement = | |
| 481 _young_gen_size_increment_supplement >> 1; | |
| 482 } | |
| 483 } | |
| 484 } | |
| 485 | |
| 486 void PSAdaptiveSizePolicy::adjust_for_minor_pause_time(bool is_full_gc, | |
| 487 size_t* desired_promo_size_ptr, size_t* desired_eden_size_ptr) { | |
| 488 | |
| 489 // Adjust the young generation size to reduce pause time of | |
| 490 // of collections. | |
| 491 // | |
| 492 // The AdaptiveSizePolicyInitializingSteps test is not used | |
| 493 // here. It has not seemed to be needed but perhaps should | |
| 494 // be added for consistency. | |
| 495 if (minor_pause_young_estimator()->decrement_will_decrease()) { | |
| 496 // reduce eden size | |
| 497 set_change_young_gen_for_min_pauses( | |
| 498 decrease_young_gen_for_min_pauses_true); | |
| 499 *desired_eden_size_ptr = *desired_eden_size_ptr - | |
| 500 eden_decrement_aligned_down(*desired_eden_size_ptr); | |
| 501 } else { | |
| 502 // EXPERIMENTAL ADJUSTMENT | |
| 503 // Only record that the estimator indicated such an action. | |
| 504 // *desired_eden_size_ptr = *desired_eden_size_ptr + eden_heap_delta; | |
| 505 set_change_young_gen_for_min_pauses( | |
| 506 increase_young_gen_for_min_pauses_true); | |
| 507 } | |
| 508 if (PSAdjustTenuredGenForMinorPause) { | |
| 509 // If the desired eden size is as small as it will get, | |
| 510 // try to adjust the old gen size. | |
| 511 if (*desired_eden_size_ptr <= _intra_generation_alignment) { | |
| 512 // Vary the old gen size to reduce the young gen pause. This | |
| 513 // may not be a good idea. This is just a test. | |
| 514 if (minor_pause_old_estimator()->decrement_will_decrease()) { | |
| 515 set_change_old_gen_for_min_pauses( | |
| 516 decrease_old_gen_for_min_pauses_true); | |
| 517 *desired_promo_size_ptr = | |
| 518 _promo_size - promo_decrement_aligned_down(*desired_promo_size_ptr); | |
| 519 } else { | |
| 520 set_change_old_gen_for_min_pauses( | |
| 521 increase_old_gen_for_min_pauses_true); | |
| 522 size_t promo_heap_delta = | |
| 523 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr); | |
| 524 if ((*desired_promo_size_ptr + promo_heap_delta) > | |
| 525 *desired_promo_size_ptr) { | |
| 526 *desired_promo_size_ptr = | |
| 527 _promo_size + promo_heap_delta; | |
| 528 } | |
| 529 } | |
| 530 } | |
| 531 } | |
| 532 } | |
| 533 | |
| 534 void PSAdaptiveSizePolicy::adjust_for_pause_time(bool is_full_gc, | |
| 535 size_t* desired_promo_size_ptr, | |
| 536 size_t* desired_eden_size_ptr) { | |
| 537 | |
| 538 size_t promo_heap_delta = 0; | |
| 539 size_t eden_heap_delta = 0; | |
| 540 // Add some checks for a threshhold for a change. For example, | |
| 541 // a change less than the required alignment is probably not worth | |
| 542 // attempting. | |
| 543 if (is_full_gc) { | |
| 544 set_decide_at_full_gc(decide_at_full_gc_true); | |
| 545 } | |
| 546 | |
| 547 if (_avg_minor_pause->padded_average() > _avg_major_pause->padded_average()) { | |
| 548 adjust_for_minor_pause_time(is_full_gc, | |
| 549 desired_promo_size_ptr, | |
| 550 desired_eden_size_ptr); | |
| 551 // major pause adjustments | |
| 552 } else if (is_full_gc) { | |
| 553 // Adjust for the major pause time only at full gc's because the | |
| 554 // affects of a change can only be seen at full gc's. | |
| 555 | |
| 556 // Reduce old generation size to reduce pause? | |
| 557 if (major_pause_old_estimator()->decrement_will_decrease()) { | |
| 558 // reduce old generation size | |
| 559 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true); | |
| 560 promo_heap_delta = promo_decrement_aligned_down(*desired_promo_size_ptr); | |
| 561 *desired_promo_size_ptr = _promo_size - promo_heap_delta; | |
| 562 } else { | |
| 563 // EXPERIMENTAL ADJUSTMENT | |
| 564 // Only record that the estimator indicated such an action. | |
| 565 // *desired_promo_size_ptr = _promo_size + | |
| 566 // promo_increment_aligned_up(*desired_promo_size_ptr); | |
| 567 set_change_old_gen_for_maj_pauses(increase_old_gen_for_maj_pauses_true); | |
| 568 } | |
| 569 if (PSAdjustYoungGenForMajorPause) { | |
| 570 // If the promo size is at the minimum (i.e., the old gen | |
| 571 // size will not actually decrease), consider changing the | |
| 572 // young gen size. | |
| 573 if (*desired_promo_size_ptr < _intra_generation_alignment) { | |
| 574 // If increasing the young generation will decrease the old gen | |
| 575 // pause, do it. | |
| 576 // During startup there is noise in the statistics for deciding | |
| 577 // on whether to increase or decrease the young gen size. For | |
| 578 // some number of iterations, just try to increase the young | |
| 579 // gen size if the major pause is too long to try and establish | |
| 580 // good statistics for later decisions. | |
| 581 if (major_pause_young_estimator()->increment_will_decrease() || | |
| 582 (_young_gen_change_for_major_pause_count | |
| 583 <= AdaptiveSizePolicyInitializingSteps)) { | |
| 584 set_change_young_gen_for_maj_pauses( | |
| 585 increase_young_gen_for_maj_pauses_true); | |
| 586 eden_heap_delta = eden_increment_aligned_up(*desired_eden_size_ptr); | |
| 587 *desired_eden_size_ptr = _eden_size + eden_heap_delta; | |
| 588 _young_gen_change_for_major_pause_count++; | |
| 589 } else { | |
| 590 // Record that decreasing the young gen size would decrease | |
| 591 // the major pause | |
| 592 set_change_young_gen_for_maj_pauses( | |
| 593 decrease_young_gen_for_maj_pauses_true); | |
| 594 eden_heap_delta = eden_decrement_aligned_down(*desired_eden_size_ptr); | |
| 595 *desired_eden_size_ptr = _eden_size - eden_heap_delta; | |
| 596 } | |
| 597 } | |
| 598 } | |
| 599 } | |
| 600 | |
| 601 if (PrintAdaptiveSizePolicy && Verbose) { | |
| 602 gclog_or_tty->print_cr( | |
| 603 "AdaptiveSizePolicy::compute_generation_free_space " | |
| 604 "adjusting gen sizes for major pause (avg %f goal %f). " | |
| 605 "desired_promo_size " SIZE_FORMAT "desired_eden_size " | |
| 606 SIZE_FORMAT | |
| 607 " promo delta " SIZE_FORMAT " eden delta " SIZE_FORMAT, | |
| 608 _avg_major_pause->average(), gc_pause_goal_sec(), | |
| 609 *desired_promo_size_ptr, *desired_eden_size_ptr, | |
| 610 promo_heap_delta, eden_heap_delta); | |
| 611 } | |
| 612 } | |
| 613 | |
| 614 void PSAdaptiveSizePolicy::adjust_for_throughput(bool is_full_gc, | |
| 615 size_t* desired_promo_size_ptr, | |
| 616 size_t* desired_eden_size_ptr) { | |
| 617 | |
| 618 // Add some checks for a threshhold for a change. For example, | |
| 619 // a change less than the required alignment is probably not worth | |
| 620 // attempting. | |
| 621 if (is_full_gc) { | |
| 622 set_decide_at_full_gc(decide_at_full_gc_true); | |
| 623 } | |
| 624 | |
| 625 if ((gc_cost() + mutator_cost()) == 0.0) { | |
| 626 return; | |
| 627 } | |
| 628 | |
| 629 if (PrintAdaptiveSizePolicy && Verbose) { | |
| 630 gclog_or_tty->print("\nPSAdaptiveSizePolicy::adjust_for_throughput(" | |
| 631 "is_full: %d, promo: " SIZE_FORMAT ", cur_eden: " SIZE_FORMAT "): ", | |
| 632 is_full_gc, *desired_promo_size_ptr, *desired_eden_size_ptr); | |
| 633 gclog_or_tty->print_cr("mutator_cost %f major_gc_cost %f " | |
| 634 "minor_gc_cost %f", mutator_cost(), major_gc_cost(), minor_gc_cost()); | |
| 635 } | |
| 636 | |
| 637 // Tenured generation | |
| 638 if (is_full_gc) { | |
| 639 | |
| 640 // Calculate the change to use for the tenured gen. | |
| 641 size_t scaled_promo_heap_delta = 0; | |
| 642 // Can the increment to the generation be scaled? | |
| 643 if (gc_cost() >= 0.0 && major_gc_cost() >= 0.0) { | |
| 644 size_t promo_heap_delta = | |
| 645 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr); | |
| 646 double scale_by_ratio = major_gc_cost() / gc_cost(); | |
| 647 scaled_promo_heap_delta = | |
| 648 (size_t) (scale_by_ratio * (double) promo_heap_delta); | |
| 649 if (PrintAdaptiveSizePolicy && Verbose) { | |
| 650 gclog_or_tty->print_cr( | |
| 651 "Scaled tenured increment: " SIZE_FORMAT " by %f down to " | |
| 652 SIZE_FORMAT, | |
| 653 promo_heap_delta, scale_by_ratio, scaled_promo_heap_delta); | |
| 654 } | |
| 655 } else if (major_gc_cost() >= 0.0) { | |
| 656 // Scaling is not going to work. If the major gc time is the | |
| 657 // larger, give it a full increment. | |
| 658 if (major_gc_cost() >= minor_gc_cost()) { | |
| 659 scaled_promo_heap_delta = | |
| 660 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr); | |
| 661 } | |
| 662 } else { | |
| 663 // Don't expect to get here but it's ok if it does | |
| 664 // in the product build since the delta will be 0 | |
| 665 // and nothing will change. | |
| 666 assert(false, "Unexpected value for gc costs"); | |
| 667 } | |
| 668 | |
| 669 switch (AdaptiveSizeThroughPutPolicy) { | |
| 670 case 1: | |
| 671 // Early in the run the statistics might not be good. Until | |
| 672 // a specific number of collections have been, use the heuristic | |
| 673 // that a larger generation size means lower collection costs. | |
| 674 if (major_collection_estimator()->increment_will_decrease() || | |
| 675 (_old_gen_change_for_major_throughput | |
| 676 <= AdaptiveSizePolicyInitializingSteps)) { | |
| 677 // Increase tenured generation size to reduce major collection cost | |
| 678 if ((*desired_promo_size_ptr + scaled_promo_heap_delta) > | |
| 679 *desired_promo_size_ptr) { | |
| 680 *desired_promo_size_ptr = _promo_size + scaled_promo_heap_delta; | |
| 681 } | |
| 682 set_change_old_gen_for_throughput( | |
| 683 increase_old_gen_for_throughput_true); | |
| 684 _old_gen_change_for_major_throughput++; | |
| 685 } else { | |
| 686 // EXPERIMENTAL ADJUSTMENT | |
| 687 // Record that decreasing the old gen size would decrease | |
| 688 // the major collection cost but don't do it. | |
| 689 // *desired_promo_size_ptr = _promo_size - | |
| 690 // promo_decrement_aligned_down(*desired_promo_size_ptr); | |
| 691 set_change_old_gen_for_throughput( | |
| 692 decrease_old_gen_for_throughput_true); | |
| 693 } | |
| 694 | |
| 695 break; | |
| 696 default: | |
| 697 // Simplest strategy | |
| 698 if ((*desired_promo_size_ptr + scaled_promo_heap_delta) > | |
| 699 *desired_promo_size_ptr) { | |
| 700 *desired_promo_size_ptr = *desired_promo_size_ptr + | |
| 701 scaled_promo_heap_delta; | |
| 702 } | |
| 703 set_change_old_gen_for_throughput( | |
| 704 increase_old_gen_for_throughput_true); | |
| 705 _old_gen_change_for_major_throughput++; | |
| 706 } | |
| 707 | |
| 708 if (PrintAdaptiveSizePolicy && Verbose) { | |
| 709 gclog_or_tty->print_cr( | |
| 710 "adjusting tenured gen for throughput (avg %f goal %f). " | |
| 711 "desired_promo_size " SIZE_FORMAT " promo_delta " SIZE_FORMAT , | |
| 712 mutator_cost(), _throughput_goal, | |
| 713 *desired_promo_size_ptr, scaled_promo_heap_delta); | |
| 714 } | |
| 715 } | |
| 716 | |
| 717 // Young generation | |
| 718 size_t scaled_eden_heap_delta = 0; | |
| 719 // Can the increment to the generation be scaled? | |
| 720 if (gc_cost() >= 0.0 && minor_gc_cost() >= 0.0) { | |
| 721 size_t eden_heap_delta = | |
| 722 eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr); | |
| 723 double scale_by_ratio = minor_gc_cost() / gc_cost(); | |
| 724 assert(scale_by_ratio <= 1.0 && scale_by_ratio >= 0.0, "Scaling is wrong"); | |
| 725 scaled_eden_heap_delta = | |
| 726 (size_t) (scale_by_ratio * (double) eden_heap_delta); | |
| 727 if (PrintAdaptiveSizePolicy && Verbose) { | |
| 728 gclog_or_tty->print_cr( | |
| 729 "Scaled eden increment: " SIZE_FORMAT " by %f down to " | |
| 730 SIZE_FORMAT, | |
| 731 eden_heap_delta, scale_by_ratio, scaled_eden_heap_delta); | |
| 732 } | |
| 733 } else if (minor_gc_cost() >= 0.0) { | |
| 734 // Scaling is not going to work. If the minor gc time is the | |
| 735 // larger, give it a full increment. | |
| 736 if (minor_gc_cost() > major_gc_cost()) { | |
| 737 scaled_eden_heap_delta = | |
| 738 eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr); | |
| 739 } | |
| 740 } else { | |
| 741 // Don't expect to get here but it's ok if it does | |
| 742 // in the product build since the delta will be 0 | |
| 743 // and nothing will change. | |
| 744 assert(false, "Unexpected value for gc costs"); | |
| 745 } | |
| 746 | |
| 747 // Use a heuristic for some number of collections to give | |
| 748 // the averages time to settle down. | |
| 749 switch (AdaptiveSizeThroughPutPolicy) { | |
| 750 case 1: | |
| 751 if (minor_collection_estimator()->increment_will_decrease() || | |
| 752 (_young_gen_change_for_minor_throughput | |
| 753 <= AdaptiveSizePolicyInitializingSteps)) { | |
| 754 // Expand young generation size to reduce frequency of | |
| 755 // of collections. | |
| 756 if ((*desired_eden_size_ptr + scaled_eden_heap_delta) > | |
| 757 *desired_eden_size_ptr) { | |
| 758 *desired_eden_size_ptr = | |
| 759 *desired_eden_size_ptr + scaled_eden_heap_delta; | |
| 760 } | |
| 761 set_change_young_gen_for_throughput( | |
| 762 increase_young_gen_for_througput_true); | |
| 763 _young_gen_change_for_minor_throughput++; | |
| 764 } else { | |
| 765 // EXPERIMENTAL ADJUSTMENT | |
| 766 // Record that decreasing the young gen size would decrease | |
| 767 // the minor collection cost but don't do it. | |
| 768 // *desired_eden_size_ptr = _eden_size - | |
| 769 // eden_decrement_aligned_down(*desired_eden_size_ptr); | |
| 770 set_change_young_gen_for_throughput( | |
| 771 decrease_young_gen_for_througput_true); | |
| 772 } | |
| 773 break; | |
| 774 default: | |
| 775 if ((*desired_eden_size_ptr + scaled_eden_heap_delta) > | |
| 776 *desired_eden_size_ptr) { | |
| 777 *desired_eden_size_ptr = | |
| 778 *desired_eden_size_ptr + scaled_eden_heap_delta; | |
| 779 } | |
| 780 set_change_young_gen_for_throughput( | |
| 781 increase_young_gen_for_througput_true); | |
| 782 _young_gen_change_for_minor_throughput++; | |
| 783 } | |
| 784 | |
| 785 if (PrintAdaptiveSizePolicy && Verbose) { | |
| 786 gclog_or_tty->print_cr( | |
| 787 "adjusting eden for throughput (avg %f goal %f). desired_eden_size " | |
| 788 SIZE_FORMAT " eden delta " SIZE_FORMAT "\n", | |
| 789 mutator_cost(), _throughput_goal, | |
| 790 *desired_eden_size_ptr, scaled_eden_heap_delta); | |
| 791 } | |
| 792 } | |
| 793 | |
| 794 size_t PSAdaptiveSizePolicy::adjust_promo_for_footprint( | |
| 795 size_t desired_promo_size, size_t desired_sum) { | |
| 796 assert(desired_promo_size <= desired_sum, "Inconsistent parameters"); | |
| 797 set_decrease_for_footprint(decrease_old_gen_for_footprint_true); | |
| 798 | |
| 799 size_t change = promo_decrement(desired_promo_size); | |
| 800 change = scale_down(change, desired_promo_size, desired_sum); | |
| 801 | |
| 802 size_t reduced_size = desired_promo_size - change; | |
| 803 | |
| 804 if (PrintAdaptiveSizePolicy && Verbose) { | |
| 805 gclog_or_tty->print_cr( | |
| 806 "AdaptiveSizePolicy::compute_generation_free_space " | |
| 807 "adjusting tenured gen for footprint. " | |
| 808 "starting promo size " SIZE_FORMAT | |
| 809 " reduced promo size " SIZE_FORMAT, | |
| 810 " promo delta " SIZE_FORMAT, | |
| 811 desired_promo_size, reduced_size, change ); | |
| 812 } | |
| 813 | |
| 814 assert(reduced_size <= desired_promo_size, "Inconsistent result"); | |
| 815 return reduced_size; | |
| 816 } | |
| 817 | |
| 818 size_t PSAdaptiveSizePolicy::adjust_eden_for_footprint( | |
| 819 size_t desired_eden_size, size_t desired_sum) { | |
| 820 assert(desired_eden_size <= desired_sum, "Inconsistent parameters"); | |
| 821 set_decrease_for_footprint(decrease_young_gen_for_footprint_true); | |
| 822 | |
| 823 size_t change = eden_decrement(desired_eden_size); | |
| 824 change = scale_down(change, desired_eden_size, desired_sum); | |
| 825 | |
| 826 size_t reduced_size = desired_eden_size - change; | |
| 827 | |
| 828 if (PrintAdaptiveSizePolicy && Verbose) { | |
| 829 gclog_or_tty->print_cr( | |
| 830 "AdaptiveSizePolicy::compute_generation_free_space " | |
| 831 "adjusting eden for footprint. " | |
| 832 " starting eden size " SIZE_FORMAT | |
| 833 " reduced eden size " SIZE_FORMAT | |
| 834 " eden delta " SIZE_FORMAT, | |
| 835 desired_eden_size, reduced_size, change); | |
| 836 } | |
| 837 | |
| 838 assert(reduced_size <= desired_eden_size, "Inconsistent result"); | |
| 839 return reduced_size; | |
| 840 } | |
| 841 | |
| 842 // Scale down "change" by the factor | |
| 843 // part / total | |
| 844 // Don't align the results. | |
| 845 | |
| 846 size_t PSAdaptiveSizePolicy::scale_down(size_t change, | |
| 847 double part, | |
| 848 double total) { | |
| 849 assert(part <= total, "Inconsistent input"); | |
| 850 size_t reduced_change = change; | |
| 851 if (total > 0) { | |
| 852 double fraction = part / total; | |
| 853 reduced_change = (size_t) (fraction * (double) change); | |
| 854 } | |
| 855 assert(reduced_change <= change, "Inconsistent result"); | |
| 856 return reduced_change; | |
| 857 } | |
| 858 | |
| 859 size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden, | |
| 860 uint percent_change) { | |
| 861 size_t eden_heap_delta; | |
| 862 eden_heap_delta = cur_eden / 100 * percent_change; | |
| 863 return eden_heap_delta; | |
| 864 } | |
| 865 | |
| 866 size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden) { | |
| 867 return eden_increment(cur_eden, YoungGenerationSizeIncrement); | |
| 868 } | |
| 869 | |
| 870 size_t PSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) { | |
| 871 size_t result = eden_increment(cur_eden, YoungGenerationSizeIncrement); | |
| 872 return align_size_up(result, _intra_generation_alignment); | |
| 873 } | |
| 874 | |
| 875 size_t PSAdaptiveSizePolicy::eden_increment_aligned_down(size_t cur_eden) { | |
| 876 size_t result = eden_increment(cur_eden); | |
| 877 return align_size_down(result, _intra_generation_alignment); | |
| 878 } | |
| 879 | |
| 880 size_t PSAdaptiveSizePolicy::eden_increment_with_supplement_aligned_up( | |
| 881 size_t cur_eden) { | |
| 882 size_t result = eden_increment(cur_eden, | |
| 883 YoungGenerationSizeIncrement + _young_gen_size_increment_supplement); | |
| 884 return align_size_up(result, _intra_generation_alignment); | |
| 885 } | |
| 886 | |
| 887 size_t PSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) { | |
| 888 size_t eden_heap_delta = eden_decrement(cur_eden); | |
| 889 return align_size_down(eden_heap_delta, _intra_generation_alignment); | |
| 890 } | |
| 891 | |
| 892 size_t PSAdaptiveSizePolicy::eden_decrement(size_t cur_eden) { | |
| 893 size_t eden_heap_delta = eden_increment(cur_eden) / | |
| 894 AdaptiveSizeDecrementScaleFactor; | |
| 895 return eden_heap_delta; | |
| 896 } | |
| 897 | |
| 898 size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo, | |
| 899 uint percent_change) { | |
| 900 size_t promo_heap_delta; | |
| 901 promo_heap_delta = cur_promo / 100 * percent_change; | |
| 902 return promo_heap_delta; | |
| 903 } | |
| 904 | |
| 905 size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo) { | |
| 906 return promo_increment(cur_promo, TenuredGenerationSizeIncrement); | |
| 907 } | |
| 908 | |
| 909 size_t PSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) { | |
| 910 size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement); | |
| 911 return align_size_up(result, _intra_generation_alignment); | |
| 912 } | |
| 913 | |
| 914 size_t PSAdaptiveSizePolicy::promo_increment_aligned_down(size_t cur_promo) { | |
| 915 size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement); | |
| 916 return align_size_down(result, _intra_generation_alignment); | |
| 917 } | |
| 918 | |
| 919 size_t PSAdaptiveSizePolicy::promo_increment_with_supplement_aligned_up( | |
| 920 size_t cur_promo) { | |
| 921 size_t result = promo_increment(cur_promo, | |
| 922 TenuredGenerationSizeIncrement + _old_gen_size_increment_supplement); | |
| 923 return align_size_up(result, _intra_generation_alignment); | |
| 924 } | |
| 925 | |
| 926 size_t PSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) { | |
| 927 size_t promo_heap_delta = promo_decrement(cur_promo); | |
| 928 return align_size_down(promo_heap_delta, _intra_generation_alignment); | |
| 929 } | |
| 930 | |
| 931 size_t PSAdaptiveSizePolicy::promo_decrement(size_t cur_promo) { | |
| 932 size_t promo_heap_delta = promo_increment(cur_promo); | |
| 933 promo_heap_delta = promo_heap_delta / AdaptiveSizeDecrementScaleFactor; | |
| 934 return promo_heap_delta; | |
| 935 } | |
| 936 | |
| 937 int PSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold( | |
| 938 bool is_survivor_overflow, | |
| 939 int tenuring_threshold, | |
| 940 size_t survivor_limit) { | |
| 941 assert(survivor_limit >= _intra_generation_alignment, | |
| 942 "survivor_limit too small"); | |
| 943 assert((size_t)align_size_down(survivor_limit, _intra_generation_alignment) | |
| 944 == survivor_limit, "survivor_limit not aligned"); | |
| 945 | |
| 946 // This method is called even if the tenuring threshold and survivor | |
| 947 // spaces are not adjusted so that the averages are sampled above. | |
| 948 if (!UsePSAdaptiveSurvivorSizePolicy || | |
| 949 !young_gen_policy_is_ready()) { | |
| 950 return tenuring_threshold; | |
| 951 } | |
| 952 | |
| 953 // We'll decide whether to increase or decrease the tenuring | |
| 954 // threshold based partly on the newly computed survivor size | |
| 955 // (if we hit the maximum limit allowed, we'll always choose to | |
| 956 // decrement the threshold). | |
| 957 bool incr_tenuring_threshold = false; | |
| 958 bool decr_tenuring_threshold = false; | |
| 959 | |
| 960 set_decrement_tenuring_threshold_for_gc_cost(false); | |
| 961 set_increment_tenuring_threshold_for_gc_cost(false); | |
| 962 set_decrement_tenuring_threshold_for_survivor_limit(false); | |
| 963 | |
| 964 if (!is_survivor_overflow) { | |
| 965 // Keep running averages on how much survived | |
| 966 | |
| 967 // We use the tenuring threshold to equalize the cost of major | |
| 968 // and minor collections. | |
| 969 // ThresholdTolerance is used to indicate how sensitive the | |
| 970 // tenuring threshold is to differences in cost betweent the | |
| 971 // collection types. | |
| 972 | |
| 973 // Get the times of interest. This involves a little work, so | |
| 974 // we cache the values here. | |
| 975 const double major_cost = major_gc_cost(); | |
| 976 const double minor_cost = minor_gc_cost(); | |
| 977 | |
| 978 if (minor_cost > major_cost * _threshold_tolerance_percent) { | |
| 979 // Minor times are getting too long; lower the threshold so | |
| 980 // less survives and more is promoted. | |
| 981 decr_tenuring_threshold = true; | |
| 982 set_decrement_tenuring_threshold_for_gc_cost(true); | |
| 983 } else if (major_cost > minor_cost * _threshold_tolerance_percent) { | |
| 984 // Major times are too long, so we want less promotion. | |
| 985 incr_tenuring_threshold = true; | |
| 986 set_increment_tenuring_threshold_for_gc_cost(true); | |
| 987 } | |
| 988 | |
| 989 } else { | |
| 990 // Survivor space overflow occurred, so promoted and survived are | |
| 991 // not accurate. We'll make our best guess by combining survived | |
| 992 // and promoted and count them as survivors. | |
| 993 // | |
| 994 // We'll lower the tenuring threshold to see if we can correct | |
| 995 // things. Also, set the survivor size conservatively. We're | |
| 996 // trying to avoid many overflows from occurring if defnew size | |
| 997 // is just too small. | |
| 998 | |
| 999 decr_tenuring_threshold = true; | |
| 1000 } | |
| 1001 | |
| 1002 // The padded average also maintains a deviation from the average; | |
| 1003 // we use this to see how good of an estimate we have of what survived. | |
| 1004 // We're trying to pad the survivor size as little as possible without | |
| 1005 // overflowing the survivor spaces. | |
| 1006 size_t target_size = align_size_up((size_t)_avg_survived->padded_average(), | |
| 1007 _intra_generation_alignment); | |
| 1008 target_size = MAX2(target_size, _intra_generation_alignment); | |
| 1009 | |
| 1010 if (target_size > survivor_limit) { | |
| 1011 // Target size is bigger than we can handle. Let's also reduce | |
| 1012 // the tenuring threshold. | |
| 1013 target_size = survivor_limit; | |
| 1014 decr_tenuring_threshold = true; | |
| 1015 set_decrement_tenuring_threshold_for_survivor_limit(true); | |
| 1016 } | |
| 1017 | |
| 1018 // Finally, increment or decrement the tenuring threshold, as decided above. | |
| 1019 // We test for decrementing first, as we might have hit the target size | |
| 1020 // limit. | |
| 1021 if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { | |
| 1022 if (tenuring_threshold > 1) { | |
| 1023 tenuring_threshold--; | |
| 1024 } | |
| 1025 } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { | |
| 1026 if (tenuring_threshold < MaxTenuringThreshold) { | |
| 1027 tenuring_threshold++; | |
| 1028 } | |
| 1029 } | |
| 1030 | |
| 1031 // We keep a running average of the amount promoted which is used | |
| 1032 // to decide when we should collect the old generation (when | |
| 1033 // the amount of old gen free space is less than what we expect to | |
| 1034 // promote). | |
| 1035 | |
| 1036 if (PrintAdaptiveSizePolicy) { | |
| 1037 // A little more detail if Verbose is on | |
| 1038 if (Verbose) { | |
| 1039 gclog_or_tty->print( " avg_survived: %f" | |
| 1040 " avg_deviation: %f", | |
| 1041 _avg_survived->average(), | |
| 1042 _avg_survived->deviation()); | |
| 1043 } | |
| 1044 | |
| 1045 gclog_or_tty->print( " avg_survived_padded_avg: %f", | |
| 1046 _avg_survived->padded_average()); | |
| 1047 | |
| 1048 if (Verbose) { | |
| 1049 gclog_or_tty->print( " avg_promoted_avg: %f" | |
| 1050 " avg_promoted_dev: %f", | |
| 1051 avg_promoted()->average(), | |
| 1052 avg_promoted()->deviation()); | |
| 1053 } | |
| 1054 | |
| 1055 gclog_or_tty->print( " avg_promoted_padded_avg: %f" | |
| 1056 " avg_pretenured_padded_avg: %f" | |
| 1057 " tenuring_thresh: %d" | |
| 1058 " target_size: " SIZE_FORMAT, | |
| 1059 avg_promoted()->padded_average(), | |
| 1060 _avg_pretenured->padded_average(), | |
| 1061 tenuring_threshold, target_size); | |
| 1062 tty->cr(); | |
| 1063 } | |
| 1064 | |
| 1065 set_survivor_size(target_size); | |
| 1066 | |
| 1067 return tenuring_threshold; | |
| 1068 } | |
| 1069 | |
| 1070 void PSAdaptiveSizePolicy::update_averages(bool is_survivor_overflow, | |
| 1071 size_t survived, | |
| 1072 size_t promoted) { | |
| 1073 // Update averages | |
| 1074 if (!is_survivor_overflow) { | |
| 1075 // Keep running averages on how much survived | |
| 1076 _avg_survived->sample(survived); | |
| 1077 } else { | |
| 1078 size_t survived_guess = survived + promoted; | |
| 1079 _avg_survived->sample(survived_guess); | |
| 1080 } | |
| 1081 avg_promoted()->sample(promoted + _avg_pretenured->padded_average()); | |
| 1082 | |
| 1083 if (PrintAdaptiveSizePolicy) { | |
| 1084 gclog_or_tty->print( | |
| 1085 "AdaptiveSizePolicy::compute_survivor_space_size_and_thresh:" | |
| 1086 " survived: " SIZE_FORMAT | |
| 1087 " promoted: " SIZE_FORMAT | |
| 1088 " overflow: %s", | |
| 1089 survived, promoted, is_survivor_overflow ? "true" : "false"); | |
| 1090 } | |
| 1091 } | |
| 1092 | |
| 1093 bool PSAdaptiveSizePolicy::print_adaptive_size_policy_on(outputStream* st) | |
| 1094 const { | |
| 1095 | |
| 1096 if (!UseAdaptiveSizePolicy) return false; | |
| 1097 | |
| 1098 return AdaptiveSizePolicy::print_adaptive_size_policy_on( | |
| 1099 st, | |
| 1100 PSScavenge::tenuring_threshold()); | |
| 1101 } |