1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,1175 @@
1.4 +/*
1.5 + * Copyright 2002-2007 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "incls/_precompiled.incl"
1.29 +#include "incls/_psAdaptiveSizePolicy.cpp.incl"
1.30 +
1.31 +#include <math.h>
1.32 +
1.33 +PSAdaptiveSizePolicy::PSAdaptiveSizePolicy(size_t init_eden_size,
1.34 + size_t init_promo_size,
1.35 + size_t init_survivor_size,
1.36 + size_t intra_generation_alignment,
1.37 + double gc_pause_goal_sec,
1.38 + double gc_minor_pause_goal_sec,
1.39 + uint gc_cost_ratio) :
1.40 + AdaptiveSizePolicy(init_eden_size,
1.41 + init_promo_size,
1.42 + init_survivor_size,
1.43 + gc_pause_goal_sec,
1.44 + gc_cost_ratio),
1.45 + _collection_cost_margin_fraction(AdaptiveSizePolicyCollectionCostMargin/
1.46 + 100.0),
1.47 + _intra_generation_alignment(intra_generation_alignment),
1.48 + _live_at_last_full_gc(init_promo_size),
1.49 + _gc_minor_pause_goal_sec(gc_minor_pause_goal_sec),
1.50 + _latest_major_mutator_interval_seconds(0),
1.51 + _young_gen_change_for_major_pause_count(0)
1.52 +{
1.53 + // Sizing policy statistics
1.54 + _avg_major_pause =
1.55 + new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding);
1.56 + _avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
1.57 + _avg_major_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
1.58 +
1.59 + _avg_base_footprint = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight);
1.60 + _major_pause_old_estimator =
1.61 + new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
1.62 + _major_pause_young_estimator =
1.63 + new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
1.64 + _major_collection_estimator =
1.65 + new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
1.66 +
1.67 + _young_gen_size_increment_supplement = YoungGenerationSizeSupplement;
1.68 + _old_gen_size_increment_supplement = TenuredGenerationSizeSupplement;
1.69 +
1.70 + // Start the timers
1.71 + _major_timer.start();
1.72 +
1.73 + _old_gen_policy_is_ready = false;
1.74 +}
1.75 +
1.76 +void PSAdaptiveSizePolicy::major_collection_begin() {
1.77 + // Update the interval time
1.78 + _major_timer.stop();
1.79 + // Save most recent collection time
1.80 + _latest_major_mutator_interval_seconds = _major_timer.seconds();
1.81 + _major_timer.reset();
1.82 + _major_timer.start();
1.83 +}
1.84 +
1.85 +void PSAdaptiveSizePolicy::update_minor_pause_old_estimator(
1.86 + double minor_pause_in_ms) {
1.87 + double promo_size_in_mbytes = ((double)_promo_size)/((double)M);
1.88 + _minor_pause_old_estimator->update(promo_size_in_mbytes,
1.89 + minor_pause_in_ms);
1.90 +}
1.91 +
1.92 +void PSAdaptiveSizePolicy::major_collection_end(size_t amount_live,
1.93 + GCCause::Cause gc_cause) {
1.94 + // Update the pause time.
1.95 + _major_timer.stop();
1.96 +
1.97 + if (gc_cause != GCCause::_java_lang_system_gc ||
1.98 + UseAdaptiveSizePolicyWithSystemGC) {
1.99 + double major_pause_in_seconds = _major_timer.seconds();
1.100 + double major_pause_in_ms = major_pause_in_seconds * MILLIUNITS;
1.101 +
1.102 + // Sample for performance counter
1.103 + _avg_major_pause->sample(major_pause_in_seconds);
1.104 +
1.105 + // Cost of collection (unit-less)
1.106 + double collection_cost = 0.0;
1.107 + if ((_latest_major_mutator_interval_seconds > 0.0) &&
1.108 + (major_pause_in_seconds > 0.0)) {
1.109 + double interval_in_seconds =
1.110 + _latest_major_mutator_interval_seconds + major_pause_in_seconds;
1.111 + collection_cost =
1.112 + major_pause_in_seconds / interval_in_seconds;
1.113 + avg_major_gc_cost()->sample(collection_cost);
1.114 +
1.115 + // Sample for performance counter
1.116 + _avg_major_interval->sample(interval_in_seconds);
1.117 + }
1.118 +
1.119 + // Calculate variables used to estimate pause time vs. gen sizes
1.120 + double eden_size_in_mbytes = ((double)_eden_size)/((double)M);
1.121 + double promo_size_in_mbytes = ((double)_promo_size)/((double)M);
1.122 + _major_pause_old_estimator->update(promo_size_in_mbytes,
1.123 + major_pause_in_ms);
1.124 + _major_pause_young_estimator->update(eden_size_in_mbytes,
1.125 + major_pause_in_ms);
1.126 +
1.127 + if (PrintAdaptiveSizePolicy && Verbose) {
1.128 + gclog_or_tty->print("psAdaptiveSizePolicy::major_collection_end: "
1.129 + "major gc cost: %f average: %f", collection_cost,
1.130 + avg_major_gc_cost()->average());
1.131 + gclog_or_tty->print_cr(" major pause: %f major period %f",
1.132 + major_pause_in_ms,
1.133 + _latest_major_mutator_interval_seconds * MILLIUNITS);
1.134 + }
1.135 +
1.136 + // Calculate variable used to estimate collection cost vs. gen sizes
1.137 + assert(collection_cost >= 0.0, "Expected to be non-negative");
1.138 + _major_collection_estimator->update(promo_size_in_mbytes,
1.139 + collection_cost);
1.140 + }
1.141 +
1.142 + // Update the amount live at the end of a full GC
1.143 + _live_at_last_full_gc = amount_live;
1.144 +
1.145 + // The policy does not have enough data until at least some major collections
1.146 + // have been done.
1.147 + if (_avg_major_pause->count() >= AdaptiveSizePolicyReadyThreshold) {
1.148 + _old_gen_policy_is_ready = true;
1.149 + }
1.150 +
1.151 + // Interval times use this timer to measure the interval that
1.152 + // the mutator runs. Reset after the GC pause has been measured.
1.153 + _major_timer.reset();
1.154 + _major_timer.start();
1.155 +}
1.156 +
1.157 +// If the remaining free space in the old generation is less that
1.158 +// that expected to be needed by the next collection, do a full
1.159 +// collection now.
1.160 +bool PSAdaptiveSizePolicy::should_full_GC(size_t old_free_in_bytes) {
1.161 +
1.162 + // A similar test is done in the scavenge's should_attempt_scavenge(). If
1.163 + // this is changed, decide if that test should also be changed.
1.164 + bool result = padded_average_promoted_in_bytes() > (float) old_free_in_bytes;
1.165 + if (PrintGCDetails && Verbose) {
1.166 + if (result) {
1.167 + gclog_or_tty->print(" full after scavenge: ");
1.168 + } else {
1.169 + gclog_or_tty->print(" no full after scavenge: ");
1.170 + }
1.171 + gclog_or_tty->print_cr(" average_promoted " SIZE_FORMAT
1.172 + " padded_average_promoted " SIZE_FORMAT
1.173 + " free in old gen " SIZE_FORMAT,
1.174 + (size_t) average_promoted_in_bytes(),
1.175 + (size_t) padded_average_promoted_in_bytes(),
1.176 + old_free_in_bytes);
1.177 + }
1.178 + return result;
1.179 +}
1.180 +
1.181 +void PSAdaptiveSizePolicy::clear_generation_free_space_flags() {
1.182 +
1.183 + AdaptiveSizePolicy::clear_generation_free_space_flags();
1.184 +
1.185 + set_change_old_gen_for_min_pauses(0);
1.186 +
1.187 + set_change_young_gen_for_maj_pauses(0);
1.188 +}
1.189 +
1.190 +
1.191 +// If this is not a full GC, only test and modify the young generation.
1.192 +
1.193 +void PSAdaptiveSizePolicy::compute_generation_free_space(size_t young_live,
1.194 + size_t eden_live,
1.195 + size_t old_live,
1.196 + size_t perm_live,
1.197 + size_t cur_eden,
1.198 + size_t max_old_gen_size,
1.199 + size_t max_eden_size,
1.200 + bool is_full_gc,
1.201 + GCCause::Cause gc_cause) {
1.202 +
1.203 + // Update statistics
1.204 + // Time statistics are updated as we go, update footprint stats here
1.205 + _avg_base_footprint->sample(BaseFootPrintEstimate + perm_live);
1.206 + avg_young_live()->sample(young_live);
1.207 + avg_eden_live()->sample(eden_live);
1.208 + if (is_full_gc) {
1.209 + // old_live is only accurate after a full gc
1.210 + avg_old_live()->sample(old_live);
1.211 + }
1.212 +
1.213 + // This code used to return if the policy was not ready , i.e.,
1.214 + // policy_is_ready() returning false. The intent was that
1.215 + // decisions below needed major collection times and so could
1.216 + // not be made before two major collections. A consequence was
1.217 + // adjustments to the young generation were not done until after
1.218 + // two major collections even if the minor collections times
1.219 + // exceeded the requested goals. Now let the young generation
1.220 + // adjust for the minor collection times. Major collection times
1.221 + // will be zero for the first collection and will naturally be
1.222 + // ignored. Tenured generation adjustments are only made at the
1.223 + // full collections so until the second major collection has
1.224 + // been reached, no tenured generation adjustments will be made.
1.225 +
1.226 + // Until we know better, desired promotion size uses the last calculation
1.227 + size_t desired_promo_size = _promo_size;
1.228 +
1.229 + // Start eden at the current value. The desired value that is stored
1.230 + // in _eden_size is not bounded by constraints of the heap and can
1.231 + // run away.
1.232 + //
1.233 + // As expected setting desired_eden_size to the current
1.234 + // value of desired_eden_size as a starting point
1.235 + // caused desired_eden_size to grow way too large and caused
1.236 + // an overflow down stream. It may have improved performance in
1.237 + // some case but is dangerous.
1.238 + size_t desired_eden_size = cur_eden;
1.239 +
1.240 +#ifdef ASSERT
1.241 + size_t original_promo_size = desired_promo_size;
1.242 + size_t original_eden_size = desired_eden_size;
1.243 +#endif
1.244 +
1.245 + // Cache some values. There's a bit of work getting these, so
1.246 + // we might save a little time.
1.247 + const double major_cost = major_gc_cost();
1.248 + const double minor_cost = minor_gc_cost();
1.249 +
1.250 + // Used for diagnostics
1.251 + clear_generation_free_space_flags();
1.252 +
1.253 + // Limits on our growth
1.254 + size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average());
1.255 +
1.256 + // This method sets the desired eden size. That plus the
1.257 + // desired survivor space sizes sets the desired young generation
1.258 + // size. This methods does not know what the desired survivor
1.259 + // size is but expects that other policy will attempt to make
1.260 + // the survivor sizes compatible with the live data in the
1.261 + // young generation. This limit is an estimate of the space left
1.262 + // in the young generation after the survivor spaces have been
1.263 + // subtracted out.
1.264 + size_t eden_limit = max_eden_size;
1.265 +
1.266 + // But don't force a promo size below the current promo size. Otherwise,
1.267 + // the promo size will shrink for no good reason.
1.268 + promo_limit = MAX2(promo_limit, _promo_size);
1.269 +
1.270 + const double gc_cost_limit = GCTimeLimit/100.0;
1.271 +
1.272 + // Which way should we go?
1.273 + // if pause requirement is not met
1.274 + // adjust size of any generation with average paus exceeding
1.275 + // the pause limit. Adjust one pause at a time (the larger)
1.276 + // and only make adjustments for the major pause at full collections.
1.277 + // else if throughput requirement not met
1.278 + // adjust the size of the generation with larger gc time. Only
1.279 + // adjust one generation at a time.
1.280 + // else
1.281 + // adjust down the total heap size. Adjust down the larger of the
1.282 + // generations.
1.283 +
1.284 + // Add some checks for a threshhold for a change. For example,
1.285 + // a change less than the necessary alignment is probably not worth
1.286 + // attempting.
1.287 +
1.288 +
1.289 + if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) ||
1.290 + (_avg_major_pause->padded_average() > gc_pause_goal_sec())) {
1.291 + //
1.292 + // Check pauses
1.293 + //
1.294 + // Make changes only to affect one of the pauses (the larger)
1.295 + // at a time.
1.296 + adjust_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size);
1.297 +
1.298 + } else if (_avg_minor_pause->padded_average() > gc_minor_pause_goal_sec()) {
1.299 + // Adjust only for the minor pause time goal
1.300 + adjust_for_minor_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size);
1.301 +
1.302 + } else if(adjusted_mutator_cost() < _throughput_goal) {
1.303 + // This branch used to require that (mutator_cost() > 0.0 in 1.4.2.
1.304 + // This sometimes resulted in skipping to the minimize footprint
1.305 + // code. Change this to try and reduce GC time if mutator time is
1.306 + // negative for whatever reason. Or for future consideration,
1.307 + // bail out of the code if mutator time is negative.
1.308 + //
1.309 + // Throughput
1.310 + //
1.311 + assert(major_cost >= 0.0, "major cost is < 0.0");
1.312 + assert(minor_cost >= 0.0, "minor cost is < 0.0");
1.313 + // Try to reduce the GC times.
1.314 + adjust_for_throughput(is_full_gc, &desired_promo_size, &desired_eden_size);
1.315 +
1.316 + } else {
1.317 +
1.318 + // Be conservative about reducing the footprint.
1.319 + // Do a minimum number of major collections first.
1.320 + // Have reasonable averages for major and minor collections costs.
1.321 + if (UseAdaptiveSizePolicyFootprintGoal &&
1.322 + young_gen_policy_is_ready() &&
1.323 + avg_major_gc_cost()->average() >= 0.0 &&
1.324 + avg_minor_gc_cost()->average() >= 0.0) {
1.325 + size_t desired_sum = desired_eden_size + desired_promo_size;
1.326 + desired_eden_size = adjust_eden_for_footprint(desired_eden_size,
1.327 + desired_sum);
1.328 + if (is_full_gc) {
1.329 + set_decide_at_full_gc(decide_at_full_gc_true);
1.330 + desired_promo_size = adjust_promo_for_footprint(desired_promo_size,
1.331 + desired_sum);
1.332 + }
1.333 + }
1.334 + }
1.335 +
1.336 + // Note we make the same tests as in the code block below; the code
1.337 + // seems a little easier to read with the printing in another block.
1.338 + if (PrintAdaptiveSizePolicy) {
1.339 + if (desired_promo_size > promo_limit) {
1.340 + // "free_in_old_gen" was the original value for used for promo_limit
1.341 + size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
1.342 + gclog_or_tty->print_cr(
1.343 + "PSAdaptiveSizePolicy::compute_generation_free_space limits:"
1.344 + " desired_promo_size: " SIZE_FORMAT
1.345 + " promo_limit: " SIZE_FORMAT
1.346 + " free_in_old_gen: " SIZE_FORMAT
1.347 + " max_old_gen_size: " SIZE_FORMAT
1.348 + " avg_old_live: " SIZE_FORMAT,
1.349 + desired_promo_size, promo_limit, free_in_old_gen,
1.350 + max_old_gen_size, (size_t) avg_old_live()->average());
1.351 + }
1.352 + if (desired_eden_size > eden_limit) {
1.353 + gclog_or_tty->print_cr(
1.354 + "AdaptiveSizePolicy::compute_generation_free_space limits:"
1.355 + " desired_eden_size: " SIZE_FORMAT
1.356 + " old_eden_size: " SIZE_FORMAT
1.357 + " eden_limit: " SIZE_FORMAT
1.358 + " cur_eden: " SIZE_FORMAT
1.359 + " max_eden_size: " SIZE_FORMAT
1.360 + " avg_young_live: " SIZE_FORMAT,
1.361 + desired_eden_size, _eden_size, eden_limit, cur_eden,
1.362 + max_eden_size, (size_t)avg_young_live()->average());
1.363 + }
1.364 + if (gc_cost() > gc_cost_limit) {
1.365 + gclog_or_tty->print_cr(
1.366 + "AdaptiveSizePolicy::compute_generation_free_space: gc time limit"
1.367 + " gc_cost: %f "
1.368 + " GCTimeLimit: %d",
1.369 + gc_cost(), GCTimeLimit);
1.370 + }
1.371 + }
1.372 +
1.373 + // Align everything and make a final limit check
1.374 + const size_t alignment = _intra_generation_alignment;
1.375 + desired_eden_size = align_size_up(desired_eden_size, alignment);
1.376 + desired_eden_size = MAX2(desired_eden_size, alignment);
1.377 + desired_promo_size = align_size_up(desired_promo_size, alignment);
1.378 + desired_promo_size = MAX2(desired_promo_size, alignment);
1.379 +
1.380 + eden_limit = align_size_down(eden_limit, alignment);
1.381 + promo_limit = align_size_down(promo_limit, alignment);
1.382 +
1.383 + // Is too much time being spent in GC?
1.384 + // Is the heap trying to grow beyond it's limits?
1.385 +
1.386 + const size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
1.387 + if (desired_promo_size > free_in_old_gen && desired_eden_size > eden_limit) {
1.388 +
1.389 + // eden_limit is the upper limit on the size of eden based on
1.390 + // the maximum size of the young generation and the sizes
1.391 + // of the survivor space.
1.392 + // The question being asked is whether the gc costs are high
1.393 + // and the space being recovered by a collection is low.
1.394 + // free_in_young_gen is the free space in the young generation
1.395 + // after a collection and promo_live is the free space in the old
1.396 + // generation after a collection.
1.397 + //
1.398 + // Use the minimum of the current value of the live in the
1.399 + // young gen or the average of the live in the young gen.
1.400 + // If the current value drops quickly, that should be taken
1.401 + // into account (i.e., don't trigger if the amount of free
1.402 + // space has suddenly jumped up). If the current is much
1.403 + // higher than the average, use the average since it represents
1.404 + // the longer term behavor.
1.405 + const size_t live_in_eden = MIN2(eden_live, (size_t) avg_eden_live()->average());
1.406 + const size_t free_in_eden = eden_limit > live_in_eden ?
1.407 + eden_limit - live_in_eden : 0;
1.408 + const size_t total_free_limit = free_in_old_gen + free_in_eden;
1.409 + const size_t total_mem = max_old_gen_size + max_eden_size;
1.410 + const double mem_free_limit = total_mem * (GCHeapFreeLimit/100.0);
1.411 + if (PrintAdaptiveSizePolicy && (Verbose ||
1.412 + (total_free_limit < (size_t) mem_free_limit))) {
1.413 + gclog_or_tty->print_cr(
1.414 + "PSAdaptiveSizePolicy::compute_generation_free_space limits:"
1.415 + " promo_limit: " SIZE_FORMAT
1.416 + " eden_limit: " SIZE_FORMAT
1.417 + " total_free_limit: " SIZE_FORMAT
1.418 + " max_old_gen_size: " SIZE_FORMAT
1.419 + " max_eden_size: " SIZE_FORMAT
1.420 + " mem_free_limit: " SIZE_FORMAT,
1.421 + promo_limit, eden_limit, total_free_limit,
1.422 + max_old_gen_size, max_eden_size,
1.423 + (size_t) mem_free_limit);
1.424 + }
1.425 +
1.426 + if (is_full_gc) {
1.427 + if (gc_cost() > gc_cost_limit &&
1.428 + total_free_limit < (size_t) mem_free_limit) {
1.429 + // Collections, on average, are taking too much time, and
1.430 + // gc_cost() > gc_cost_limit
1.431 + // we have too little space available after a full gc.
1.432 + // total_free_limit < mem_free_limit
1.433 + // where
1.434 + // total_free_limit is the free space available in
1.435 + // both generations
1.436 + // total_mem is the total space available for allocation
1.437 + // in both generations (survivor spaces are not included
1.438 + // just as they are not included in eden_limit).
1.439 + // mem_free_limit is a fraction of total_mem judged to be an
1.440 + // acceptable amount that is still unused.
1.441 + // The heap can ask for the value of this variable when deciding
1.442 + // whether to thrown an OutOfMemory error.
1.443 + // Note that the gc time limit test only works for the collections
1.444 + // of the young gen + tenured gen and not for collections of the
1.445 + // permanent gen. That is because the calculation of the space
1.446 + // freed by the collection is the free space in the young gen +
1.447 + // tenured gen.
1.448 + // Ignore explicit GC's. Ignoring explicit GC's at this level
1.449 + // is the equivalent of the GC did not happen as far as the
1.450 + // overhead calculation is concerted (i.e., the flag is not set
1.451 + // and the count is not affected). Also the average will not
1.452 + // have been updated unless UseAdaptiveSizePolicyWithSystemGC is on.
1.453 + if (!GCCause::is_user_requested_gc(gc_cause) &&
1.454 + !GCCause::is_serviceability_requested_gc(gc_cause)) {
1.455 + inc_gc_time_limit_count();
1.456 + if (UseGCOverheadLimit &&
1.457 + (gc_time_limit_count() > AdaptiveSizePolicyGCTimeLimitThreshold)){
1.458 + // All conditions have been met for throwing an out-of-memory
1.459 + _gc_time_limit_exceeded = true;
1.460 + // Avoid consecutive OOM due to the gc time limit by resetting
1.461 + // the counter.
1.462 + reset_gc_time_limit_count();
1.463 + }
1.464 + _print_gc_time_limit_would_be_exceeded = true;
1.465 + }
1.466 + } else {
1.467 + // Did not exceed overhead limits
1.468 + reset_gc_time_limit_count();
1.469 + }
1.470 + }
1.471 + }
1.472 +
1.473 +
1.474 + // And one last limit check, now that we've aligned things.
1.475 + if (desired_eden_size > eden_limit) {
1.476 + // If the policy says to get a larger eden but
1.477 + // is hitting the limit, don't decrease eden.
1.478 + // This can lead to a general drifting down of the
1.479 + // eden size. Let the tenuring calculation push more
1.480 + // into the old gen.
1.481 + desired_eden_size = MAX2(eden_limit, cur_eden);
1.482 + }
1.483 + desired_promo_size = MIN2(desired_promo_size, promo_limit);
1.484 +
1.485 +
1.486 + if (PrintAdaptiveSizePolicy) {
1.487 + // Timing stats
1.488 + gclog_or_tty->print(
1.489 + "PSAdaptiveSizePolicy::compute_generation_free_space: costs"
1.490 + " minor_time: %f"
1.491 + " major_cost: %f"
1.492 + " mutator_cost: %f"
1.493 + " throughput_goal: %f",
1.494 + minor_gc_cost(), major_gc_cost(), mutator_cost(),
1.495 + _throughput_goal);
1.496 +
1.497 + // We give more details if Verbose is set
1.498 + if (Verbose) {
1.499 + gclog_or_tty->print( " minor_pause: %f"
1.500 + " major_pause: %f"
1.501 + " minor_interval: %f"
1.502 + " major_interval: %f"
1.503 + " pause_goal: %f",
1.504 + _avg_minor_pause->padded_average(),
1.505 + _avg_major_pause->padded_average(),
1.506 + _avg_minor_interval->average(),
1.507 + _avg_major_interval->average(),
1.508 + gc_pause_goal_sec());
1.509 + }
1.510 +
1.511 + // Footprint stats
1.512 + gclog_or_tty->print( " live_space: " SIZE_FORMAT
1.513 + " free_space: " SIZE_FORMAT,
1.514 + live_space(), free_space());
1.515 + // More detail
1.516 + if (Verbose) {
1.517 + gclog_or_tty->print( " base_footprint: " SIZE_FORMAT
1.518 + " avg_young_live: " SIZE_FORMAT
1.519 + " avg_old_live: " SIZE_FORMAT,
1.520 + (size_t)_avg_base_footprint->average(),
1.521 + (size_t)avg_young_live()->average(),
1.522 + (size_t)avg_old_live()->average());
1.523 + }
1.524 +
1.525 + // And finally, our old and new sizes.
1.526 + gclog_or_tty->print(" old_promo_size: " SIZE_FORMAT
1.527 + " old_eden_size: " SIZE_FORMAT
1.528 + " desired_promo_size: " SIZE_FORMAT
1.529 + " desired_eden_size: " SIZE_FORMAT,
1.530 + _promo_size, _eden_size,
1.531 + desired_promo_size, desired_eden_size);
1.532 + gclog_or_tty->cr();
1.533 + }
1.534 +
1.535 + decay_supplemental_growth(is_full_gc);
1.536 +
1.537 + set_promo_size(desired_promo_size);
1.538 + set_eden_size(desired_eden_size);
1.539 +};
1.540 +
1.541 +void PSAdaptiveSizePolicy::decay_supplemental_growth(bool is_full_gc) {
1.542 + // Decay the supplemental increment? Decay the supplement growth
1.543 + // factor even if it is not used. It is only meant to give a boost
1.544 + // to the initial growth and if it is not used, then it was not
1.545 + // needed.
1.546 + if (is_full_gc) {
1.547 + // Don't wait for the threshold value for the major collections. If
1.548 + // here, the supplemental growth term was used and should decay.
1.549 + if ((_avg_major_pause->count() % TenuredGenerationSizeSupplementDecay)
1.550 + == 0) {
1.551 + _old_gen_size_increment_supplement =
1.552 + _old_gen_size_increment_supplement >> 1;
1.553 + }
1.554 + } else {
1.555 + if ((_avg_minor_pause->count() >= AdaptiveSizePolicyReadyThreshold) &&
1.556 + (_avg_minor_pause->count() % YoungGenerationSizeSupplementDecay) == 0) {
1.557 + _young_gen_size_increment_supplement =
1.558 + _young_gen_size_increment_supplement >> 1;
1.559 + }
1.560 + }
1.561 +}
1.562 +
1.563 +void PSAdaptiveSizePolicy::adjust_for_minor_pause_time(bool is_full_gc,
1.564 + size_t* desired_promo_size_ptr, size_t* desired_eden_size_ptr) {
1.565 +
1.566 + // Adjust the young generation size to reduce pause time of
1.567 + // of collections.
1.568 + //
1.569 + // The AdaptiveSizePolicyInitializingSteps test is not used
1.570 + // here. It has not seemed to be needed but perhaps should
1.571 + // be added for consistency.
1.572 + if (minor_pause_young_estimator()->decrement_will_decrease()) {
1.573 + // reduce eden size
1.574 + set_change_young_gen_for_min_pauses(
1.575 + decrease_young_gen_for_min_pauses_true);
1.576 + *desired_eden_size_ptr = *desired_eden_size_ptr -
1.577 + eden_decrement_aligned_down(*desired_eden_size_ptr);
1.578 + } else {
1.579 + // EXPERIMENTAL ADJUSTMENT
1.580 + // Only record that the estimator indicated such an action.
1.581 + // *desired_eden_size_ptr = *desired_eden_size_ptr + eden_heap_delta;
1.582 + set_change_young_gen_for_min_pauses(
1.583 + increase_young_gen_for_min_pauses_true);
1.584 + }
1.585 + if (PSAdjustTenuredGenForMinorPause) {
1.586 + // If the desired eden size is as small as it will get,
1.587 + // try to adjust the old gen size.
1.588 + if (*desired_eden_size_ptr <= _intra_generation_alignment) {
1.589 + // Vary the old gen size to reduce the young gen pause. This
1.590 + // may not be a good idea. This is just a test.
1.591 + if (minor_pause_old_estimator()->decrement_will_decrease()) {
1.592 + set_change_old_gen_for_min_pauses(
1.593 + decrease_old_gen_for_min_pauses_true);
1.594 + *desired_promo_size_ptr =
1.595 + _promo_size - promo_decrement_aligned_down(*desired_promo_size_ptr);
1.596 + } else {
1.597 + set_change_old_gen_for_min_pauses(
1.598 + increase_old_gen_for_min_pauses_true);
1.599 + size_t promo_heap_delta =
1.600 + promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
1.601 + if ((*desired_promo_size_ptr + promo_heap_delta) >
1.602 + *desired_promo_size_ptr) {
1.603 + *desired_promo_size_ptr =
1.604 + _promo_size + promo_heap_delta;
1.605 + }
1.606 + }
1.607 + }
1.608 + }
1.609 +}
1.610 +
1.611 +void PSAdaptiveSizePolicy::adjust_for_pause_time(bool is_full_gc,
1.612 + size_t* desired_promo_size_ptr,
1.613 + size_t* desired_eden_size_ptr) {
1.614 +
1.615 + size_t promo_heap_delta = 0;
1.616 + size_t eden_heap_delta = 0;
1.617 + // Add some checks for a threshhold for a change. For example,
1.618 + // a change less than the required alignment is probably not worth
1.619 + // attempting.
1.620 + if (is_full_gc) {
1.621 + set_decide_at_full_gc(decide_at_full_gc_true);
1.622 + }
1.623 +
1.624 + if (_avg_minor_pause->padded_average() > _avg_major_pause->padded_average()) {
1.625 + adjust_for_minor_pause_time(is_full_gc,
1.626 + desired_promo_size_ptr,
1.627 + desired_eden_size_ptr);
1.628 + // major pause adjustments
1.629 + } else if (is_full_gc) {
1.630 + // Adjust for the major pause time only at full gc's because the
1.631 + // affects of a change can only be seen at full gc's.
1.632 +
1.633 + // Reduce old generation size to reduce pause?
1.634 + if (major_pause_old_estimator()->decrement_will_decrease()) {
1.635 + // reduce old generation size
1.636 + set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true);
1.637 + promo_heap_delta = promo_decrement_aligned_down(*desired_promo_size_ptr);
1.638 + *desired_promo_size_ptr = _promo_size - promo_heap_delta;
1.639 + } else {
1.640 + // EXPERIMENTAL ADJUSTMENT
1.641 + // Only record that the estimator indicated such an action.
1.642 + // *desired_promo_size_ptr = _promo_size +
1.643 + // promo_increment_aligned_up(*desired_promo_size_ptr);
1.644 + set_change_old_gen_for_maj_pauses(increase_old_gen_for_maj_pauses_true);
1.645 + }
1.646 + if (PSAdjustYoungGenForMajorPause) {
1.647 + // If the promo size is at the minimum (i.e., the old gen
1.648 + // size will not actually decrease), consider changing the
1.649 + // young gen size.
1.650 + if (*desired_promo_size_ptr < _intra_generation_alignment) {
1.651 + // If increasing the young generation will decrease the old gen
1.652 + // pause, do it.
1.653 + // During startup there is noise in the statistics for deciding
1.654 + // on whether to increase or decrease the young gen size. For
1.655 + // some number of iterations, just try to increase the young
1.656 + // gen size if the major pause is too long to try and establish
1.657 + // good statistics for later decisions.
1.658 + if (major_pause_young_estimator()->increment_will_decrease() ||
1.659 + (_young_gen_change_for_major_pause_count
1.660 + <= AdaptiveSizePolicyInitializingSteps)) {
1.661 + set_change_young_gen_for_maj_pauses(
1.662 + increase_young_gen_for_maj_pauses_true);
1.663 + eden_heap_delta = eden_increment_aligned_up(*desired_eden_size_ptr);
1.664 + *desired_eden_size_ptr = _eden_size + eden_heap_delta;
1.665 + _young_gen_change_for_major_pause_count++;
1.666 + } else {
1.667 + // Record that decreasing the young gen size would decrease
1.668 + // the major pause
1.669 + set_change_young_gen_for_maj_pauses(
1.670 + decrease_young_gen_for_maj_pauses_true);
1.671 + eden_heap_delta = eden_decrement_aligned_down(*desired_eden_size_ptr);
1.672 + *desired_eden_size_ptr = _eden_size - eden_heap_delta;
1.673 + }
1.674 + }
1.675 + }
1.676 + }
1.677 +
1.678 + if (PrintAdaptiveSizePolicy && Verbose) {
1.679 + gclog_or_tty->print_cr(
1.680 + "AdaptiveSizePolicy::compute_generation_free_space "
1.681 + "adjusting gen sizes for major pause (avg %f goal %f). "
1.682 + "desired_promo_size " SIZE_FORMAT "desired_eden_size "
1.683 + SIZE_FORMAT
1.684 + " promo delta " SIZE_FORMAT " eden delta " SIZE_FORMAT,
1.685 + _avg_major_pause->average(), gc_pause_goal_sec(),
1.686 + *desired_promo_size_ptr, *desired_eden_size_ptr,
1.687 + promo_heap_delta, eden_heap_delta);
1.688 + }
1.689 +}
1.690 +
1.691 +void PSAdaptiveSizePolicy::adjust_for_throughput(bool is_full_gc,
1.692 + size_t* desired_promo_size_ptr,
1.693 + size_t* desired_eden_size_ptr) {
1.694 +
1.695 + // Add some checks for a threshhold for a change. For example,
1.696 + // a change less than the required alignment is probably not worth
1.697 + // attempting.
1.698 + if (is_full_gc) {
1.699 + set_decide_at_full_gc(decide_at_full_gc_true);
1.700 + }
1.701 +
1.702 + if ((gc_cost() + mutator_cost()) == 0.0) {
1.703 + return;
1.704 + }
1.705 +
1.706 + if (PrintAdaptiveSizePolicy && Verbose) {
1.707 + gclog_or_tty->print("\nPSAdaptiveSizePolicy::adjust_for_throughput("
1.708 + "is_full: %d, promo: " SIZE_FORMAT ", cur_eden: " SIZE_FORMAT "): ",
1.709 + is_full_gc, *desired_promo_size_ptr, *desired_eden_size_ptr);
1.710 + gclog_or_tty->print_cr("mutator_cost %f major_gc_cost %f "
1.711 + "minor_gc_cost %f", mutator_cost(), major_gc_cost(), minor_gc_cost());
1.712 + }
1.713 +
1.714 + // Tenured generation
1.715 + if (is_full_gc) {
1.716 +
1.717 + // Calculate the change to use for the tenured gen.
1.718 + size_t scaled_promo_heap_delta = 0;
1.719 + // Can the increment to the generation be scaled?
1.720 + if (gc_cost() >= 0.0 && major_gc_cost() >= 0.0) {
1.721 + size_t promo_heap_delta =
1.722 + promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
1.723 + double scale_by_ratio = major_gc_cost() / gc_cost();
1.724 + scaled_promo_heap_delta =
1.725 + (size_t) (scale_by_ratio * (double) promo_heap_delta);
1.726 + if (PrintAdaptiveSizePolicy && Verbose) {
1.727 + gclog_or_tty->print_cr(
1.728 + "Scaled tenured increment: " SIZE_FORMAT " by %f down to "
1.729 + SIZE_FORMAT,
1.730 + promo_heap_delta, scale_by_ratio, scaled_promo_heap_delta);
1.731 + }
1.732 + } else if (major_gc_cost() >= 0.0) {
1.733 + // Scaling is not going to work. If the major gc time is the
1.734 + // larger, give it a full increment.
1.735 + if (major_gc_cost() >= minor_gc_cost()) {
1.736 + scaled_promo_heap_delta =
1.737 + promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
1.738 + }
1.739 + } else {
1.740 + // Don't expect to get here but it's ok if it does
1.741 + // in the product build since the delta will be 0
1.742 + // and nothing will change.
1.743 + assert(false, "Unexpected value for gc costs");
1.744 + }
1.745 +
1.746 + switch (AdaptiveSizeThroughPutPolicy) {
1.747 + case 1:
1.748 + // Early in the run the statistics might not be good. Until
1.749 + // a specific number of collections have been, use the heuristic
1.750 + // that a larger generation size means lower collection costs.
1.751 + if (major_collection_estimator()->increment_will_decrease() ||
1.752 + (_old_gen_change_for_major_throughput
1.753 + <= AdaptiveSizePolicyInitializingSteps)) {
1.754 + // Increase tenured generation size to reduce major collection cost
1.755 + if ((*desired_promo_size_ptr + scaled_promo_heap_delta) >
1.756 + *desired_promo_size_ptr) {
1.757 + *desired_promo_size_ptr = _promo_size + scaled_promo_heap_delta;
1.758 + }
1.759 + set_change_old_gen_for_throughput(
1.760 + increase_old_gen_for_throughput_true);
1.761 + _old_gen_change_for_major_throughput++;
1.762 + } else {
1.763 + // EXPERIMENTAL ADJUSTMENT
1.764 + // Record that decreasing the old gen size would decrease
1.765 + // the major collection cost but don't do it.
1.766 + // *desired_promo_size_ptr = _promo_size -
1.767 + // promo_decrement_aligned_down(*desired_promo_size_ptr);
1.768 + set_change_old_gen_for_throughput(
1.769 + decrease_old_gen_for_throughput_true);
1.770 + }
1.771 +
1.772 + break;
1.773 + default:
1.774 + // Simplest strategy
1.775 + if ((*desired_promo_size_ptr + scaled_promo_heap_delta) >
1.776 + *desired_promo_size_ptr) {
1.777 + *desired_promo_size_ptr = *desired_promo_size_ptr +
1.778 + scaled_promo_heap_delta;
1.779 + }
1.780 + set_change_old_gen_for_throughput(
1.781 + increase_old_gen_for_throughput_true);
1.782 + _old_gen_change_for_major_throughput++;
1.783 + }
1.784 +
1.785 + if (PrintAdaptiveSizePolicy && Verbose) {
1.786 + gclog_or_tty->print_cr(
1.787 + "adjusting tenured gen for throughput (avg %f goal %f). "
1.788 + "desired_promo_size " SIZE_FORMAT " promo_delta " SIZE_FORMAT ,
1.789 + mutator_cost(), _throughput_goal,
1.790 + *desired_promo_size_ptr, scaled_promo_heap_delta);
1.791 + }
1.792 + }
1.793 +
1.794 + // Young generation
1.795 + size_t scaled_eden_heap_delta = 0;
1.796 + // Can the increment to the generation be scaled?
1.797 + if (gc_cost() >= 0.0 && minor_gc_cost() >= 0.0) {
1.798 + size_t eden_heap_delta =
1.799 + eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr);
1.800 + double scale_by_ratio = minor_gc_cost() / gc_cost();
1.801 + assert(scale_by_ratio <= 1.0 && scale_by_ratio >= 0.0, "Scaling is wrong");
1.802 + scaled_eden_heap_delta =
1.803 + (size_t) (scale_by_ratio * (double) eden_heap_delta);
1.804 + if (PrintAdaptiveSizePolicy && Verbose) {
1.805 + gclog_or_tty->print_cr(
1.806 + "Scaled eden increment: " SIZE_FORMAT " by %f down to "
1.807 + SIZE_FORMAT,
1.808 + eden_heap_delta, scale_by_ratio, scaled_eden_heap_delta);
1.809 + }
1.810 + } else if (minor_gc_cost() >= 0.0) {
1.811 + // Scaling is not going to work. If the minor gc time is the
1.812 + // larger, give it a full increment.
1.813 + if (minor_gc_cost() > major_gc_cost()) {
1.814 + scaled_eden_heap_delta =
1.815 + eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr);
1.816 + }
1.817 + } else {
1.818 + // Don't expect to get here but it's ok if it does
1.819 + // in the product build since the delta will be 0
1.820 + // and nothing will change.
1.821 + assert(false, "Unexpected value for gc costs");
1.822 + }
1.823 +
1.824 + // Use a heuristic for some number of collections to give
1.825 + // the averages time to settle down.
1.826 + switch (AdaptiveSizeThroughPutPolicy) {
1.827 + case 1:
1.828 + if (minor_collection_estimator()->increment_will_decrease() ||
1.829 + (_young_gen_change_for_minor_throughput
1.830 + <= AdaptiveSizePolicyInitializingSteps)) {
1.831 + // Expand young generation size to reduce frequency of
1.832 + // of collections.
1.833 + if ((*desired_eden_size_ptr + scaled_eden_heap_delta) >
1.834 + *desired_eden_size_ptr) {
1.835 + *desired_eden_size_ptr =
1.836 + *desired_eden_size_ptr + scaled_eden_heap_delta;
1.837 + }
1.838 + set_change_young_gen_for_throughput(
1.839 + increase_young_gen_for_througput_true);
1.840 + _young_gen_change_for_minor_throughput++;
1.841 + } else {
1.842 + // EXPERIMENTAL ADJUSTMENT
1.843 + // Record that decreasing the young gen size would decrease
1.844 + // the minor collection cost but don't do it.
1.845 + // *desired_eden_size_ptr = _eden_size -
1.846 + // eden_decrement_aligned_down(*desired_eden_size_ptr);
1.847 + set_change_young_gen_for_throughput(
1.848 + decrease_young_gen_for_througput_true);
1.849 + }
1.850 + break;
1.851 + default:
1.852 + if ((*desired_eden_size_ptr + scaled_eden_heap_delta) >
1.853 + *desired_eden_size_ptr) {
1.854 + *desired_eden_size_ptr =
1.855 + *desired_eden_size_ptr + scaled_eden_heap_delta;
1.856 + }
1.857 + set_change_young_gen_for_throughput(
1.858 + increase_young_gen_for_througput_true);
1.859 + _young_gen_change_for_minor_throughput++;
1.860 + }
1.861 +
1.862 + if (PrintAdaptiveSizePolicy && Verbose) {
1.863 + gclog_or_tty->print_cr(
1.864 + "adjusting eden for throughput (avg %f goal %f). desired_eden_size "
1.865 + SIZE_FORMAT " eden delta " SIZE_FORMAT "\n",
1.866 + mutator_cost(), _throughput_goal,
1.867 + *desired_eden_size_ptr, scaled_eden_heap_delta);
1.868 + }
1.869 +}
1.870 +
1.871 +size_t PSAdaptiveSizePolicy::adjust_promo_for_footprint(
1.872 + size_t desired_promo_size, size_t desired_sum) {
1.873 + assert(desired_promo_size <= desired_sum, "Inconsistent parameters");
1.874 + set_decrease_for_footprint(decrease_old_gen_for_footprint_true);
1.875 +
1.876 + size_t change = promo_decrement(desired_promo_size);
1.877 + change = scale_down(change, desired_promo_size, desired_sum);
1.878 +
1.879 + size_t reduced_size = desired_promo_size - change;
1.880 +
1.881 + if (PrintAdaptiveSizePolicy && Verbose) {
1.882 + gclog_or_tty->print_cr(
1.883 + "AdaptiveSizePolicy::compute_generation_free_space "
1.884 + "adjusting tenured gen for footprint. "
1.885 + "starting promo size " SIZE_FORMAT
1.886 + " reduced promo size " SIZE_FORMAT,
1.887 + " promo delta " SIZE_FORMAT,
1.888 + desired_promo_size, reduced_size, change );
1.889 + }
1.890 +
1.891 + assert(reduced_size <= desired_promo_size, "Inconsistent result");
1.892 + return reduced_size;
1.893 +}
1.894 +
1.895 +size_t PSAdaptiveSizePolicy::adjust_eden_for_footprint(
1.896 + size_t desired_eden_size, size_t desired_sum) {
1.897 + assert(desired_eden_size <= desired_sum, "Inconsistent parameters");
1.898 + set_decrease_for_footprint(decrease_young_gen_for_footprint_true);
1.899 +
1.900 + size_t change = eden_decrement(desired_eden_size);
1.901 + change = scale_down(change, desired_eden_size, desired_sum);
1.902 +
1.903 + size_t reduced_size = desired_eden_size - change;
1.904 +
1.905 + if (PrintAdaptiveSizePolicy && Verbose) {
1.906 + gclog_or_tty->print_cr(
1.907 + "AdaptiveSizePolicy::compute_generation_free_space "
1.908 + "adjusting eden for footprint. "
1.909 + " starting eden size " SIZE_FORMAT
1.910 + " reduced eden size " SIZE_FORMAT
1.911 + " eden delta " SIZE_FORMAT,
1.912 + desired_eden_size, reduced_size, change);
1.913 + }
1.914 +
1.915 + assert(reduced_size <= desired_eden_size, "Inconsistent result");
1.916 + return reduced_size;
1.917 +}
1.918 +
1.919 +// Scale down "change" by the factor
1.920 +// part / total
1.921 +// Don't align the results.
1.922 +
1.923 +size_t PSAdaptiveSizePolicy::scale_down(size_t change,
1.924 + double part,
1.925 + double total) {
1.926 + assert(part <= total, "Inconsistent input");
1.927 + size_t reduced_change = change;
1.928 + if (total > 0) {
1.929 + double fraction = part / total;
1.930 + reduced_change = (size_t) (fraction * (double) change);
1.931 + }
1.932 + assert(reduced_change <= change, "Inconsistent result");
1.933 + return reduced_change;
1.934 +}
1.935 +
1.936 +size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden,
1.937 + uint percent_change) {
1.938 + size_t eden_heap_delta;
1.939 + eden_heap_delta = cur_eden / 100 * percent_change;
1.940 + return eden_heap_delta;
1.941 +}
1.942 +
1.943 +size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden) {
1.944 + return eden_increment(cur_eden, YoungGenerationSizeIncrement);
1.945 +}
1.946 +
1.947 +size_t PSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) {
1.948 + size_t result = eden_increment(cur_eden, YoungGenerationSizeIncrement);
1.949 + return align_size_up(result, _intra_generation_alignment);
1.950 +}
1.951 +
1.952 +size_t PSAdaptiveSizePolicy::eden_increment_aligned_down(size_t cur_eden) {
1.953 + size_t result = eden_increment(cur_eden);
1.954 + return align_size_down(result, _intra_generation_alignment);
1.955 +}
1.956 +
1.957 +size_t PSAdaptiveSizePolicy::eden_increment_with_supplement_aligned_up(
1.958 + size_t cur_eden) {
1.959 + size_t result = eden_increment(cur_eden,
1.960 + YoungGenerationSizeIncrement + _young_gen_size_increment_supplement);
1.961 + return align_size_up(result, _intra_generation_alignment);
1.962 +}
1.963 +
1.964 +size_t PSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) {
1.965 + size_t eden_heap_delta = eden_decrement(cur_eden);
1.966 + return align_size_down(eden_heap_delta, _intra_generation_alignment);
1.967 +}
1.968 +
1.969 +size_t PSAdaptiveSizePolicy::eden_decrement(size_t cur_eden) {
1.970 + size_t eden_heap_delta = eden_increment(cur_eden) /
1.971 + AdaptiveSizeDecrementScaleFactor;
1.972 + return eden_heap_delta;
1.973 +}
1.974 +
1.975 +size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo,
1.976 + uint percent_change) {
1.977 + size_t promo_heap_delta;
1.978 + promo_heap_delta = cur_promo / 100 * percent_change;
1.979 + return promo_heap_delta;
1.980 +}
1.981 +
1.982 +size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo) {
1.983 + return promo_increment(cur_promo, TenuredGenerationSizeIncrement);
1.984 +}
1.985 +
1.986 +size_t PSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) {
1.987 + size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement);
1.988 + return align_size_up(result, _intra_generation_alignment);
1.989 +}
1.990 +
1.991 +size_t PSAdaptiveSizePolicy::promo_increment_aligned_down(size_t cur_promo) {
1.992 + size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement);
1.993 + return align_size_down(result, _intra_generation_alignment);
1.994 +}
1.995 +
1.996 +size_t PSAdaptiveSizePolicy::promo_increment_with_supplement_aligned_up(
1.997 + size_t cur_promo) {
1.998 + size_t result = promo_increment(cur_promo,
1.999 + TenuredGenerationSizeIncrement + _old_gen_size_increment_supplement);
1.1000 + return align_size_up(result, _intra_generation_alignment);
1.1001 +}
1.1002 +
1.1003 +size_t PSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) {
1.1004 + size_t promo_heap_delta = promo_decrement(cur_promo);
1.1005 + return align_size_down(promo_heap_delta, _intra_generation_alignment);
1.1006 +}
1.1007 +
1.1008 +size_t PSAdaptiveSizePolicy::promo_decrement(size_t cur_promo) {
1.1009 + size_t promo_heap_delta = promo_increment(cur_promo);
1.1010 + promo_heap_delta = promo_heap_delta / AdaptiveSizeDecrementScaleFactor;
1.1011 + return promo_heap_delta;
1.1012 +}
1.1013 +
1.1014 +int PSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold(
1.1015 + bool is_survivor_overflow,
1.1016 + int tenuring_threshold,
1.1017 + size_t survivor_limit) {
1.1018 + assert(survivor_limit >= _intra_generation_alignment,
1.1019 + "survivor_limit too small");
1.1020 + assert((size_t)align_size_down(survivor_limit, _intra_generation_alignment)
1.1021 + == survivor_limit, "survivor_limit not aligned");
1.1022 +
1.1023 + // This method is called even if the tenuring threshold and survivor
1.1024 + // spaces are not adjusted so that the averages are sampled above.
1.1025 + if (!UsePSAdaptiveSurvivorSizePolicy ||
1.1026 + !young_gen_policy_is_ready()) {
1.1027 + return tenuring_threshold;
1.1028 + }
1.1029 +
1.1030 + // We'll decide whether to increase or decrease the tenuring
1.1031 + // threshold based partly on the newly computed survivor size
1.1032 + // (if we hit the maximum limit allowed, we'll always choose to
1.1033 + // decrement the threshold).
1.1034 + bool incr_tenuring_threshold = false;
1.1035 + bool decr_tenuring_threshold = false;
1.1036 +
1.1037 + set_decrement_tenuring_threshold_for_gc_cost(false);
1.1038 + set_increment_tenuring_threshold_for_gc_cost(false);
1.1039 + set_decrement_tenuring_threshold_for_survivor_limit(false);
1.1040 +
1.1041 + if (!is_survivor_overflow) {
1.1042 + // Keep running averages on how much survived
1.1043 +
1.1044 + // We use the tenuring threshold to equalize the cost of major
1.1045 + // and minor collections.
1.1046 + // ThresholdTolerance is used to indicate how sensitive the
1.1047 + // tenuring threshold is to differences in cost betweent the
1.1048 + // collection types.
1.1049 +
1.1050 + // Get the times of interest. This involves a little work, so
1.1051 + // we cache the values here.
1.1052 + const double major_cost = major_gc_cost();
1.1053 + const double minor_cost = minor_gc_cost();
1.1054 +
1.1055 + if (minor_cost > major_cost * _threshold_tolerance_percent) {
1.1056 + // Minor times are getting too long; lower the threshold so
1.1057 + // less survives and more is promoted.
1.1058 + decr_tenuring_threshold = true;
1.1059 + set_decrement_tenuring_threshold_for_gc_cost(true);
1.1060 + } else if (major_cost > minor_cost * _threshold_tolerance_percent) {
1.1061 + // Major times are too long, so we want less promotion.
1.1062 + incr_tenuring_threshold = true;
1.1063 + set_increment_tenuring_threshold_for_gc_cost(true);
1.1064 + }
1.1065 +
1.1066 + } else {
1.1067 + // Survivor space overflow occurred, so promoted and survived are
1.1068 + // not accurate. We'll make our best guess by combining survived
1.1069 + // and promoted and count them as survivors.
1.1070 + //
1.1071 + // We'll lower the tenuring threshold to see if we can correct
1.1072 + // things. Also, set the survivor size conservatively. We're
1.1073 + // trying to avoid many overflows from occurring if defnew size
1.1074 + // is just too small.
1.1075 +
1.1076 + decr_tenuring_threshold = true;
1.1077 + }
1.1078 +
1.1079 + // The padded average also maintains a deviation from the average;
1.1080 + // we use this to see how good of an estimate we have of what survived.
1.1081 + // We're trying to pad the survivor size as little as possible without
1.1082 + // overflowing the survivor spaces.
1.1083 + size_t target_size = align_size_up((size_t)_avg_survived->padded_average(),
1.1084 + _intra_generation_alignment);
1.1085 + target_size = MAX2(target_size, _intra_generation_alignment);
1.1086 +
1.1087 + if (target_size > survivor_limit) {
1.1088 + // Target size is bigger than we can handle. Let's also reduce
1.1089 + // the tenuring threshold.
1.1090 + target_size = survivor_limit;
1.1091 + decr_tenuring_threshold = true;
1.1092 + set_decrement_tenuring_threshold_for_survivor_limit(true);
1.1093 + }
1.1094 +
1.1095 + // Finally, increment or decrement the tenuring threshold, as decided above.
1.1096 + // We test for decrementing first, as we might have hit the target size
1.1097 + // limit.
1.1098 + if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1.1099 + if (tenuring_threshold > 1) {
1.1100 + tenuring_threshold--;
1.1101 + }
1.1102 + } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
1.1103 + if (tenuring_threshold < MaxTenuringThreshold) {
1.1104 + tenuring_threshold++;
1.1105 + }
1.1106 + }
1.1107 +
1.1108 + // We keep a running average of the amount promoted which is used
1.1109 + // to decide when we should collect the old generation (when
1.1110 + // the amount of old gen free space is less than what we expect to
1.1111 + // promote).
1.1112 +
1.1113 + if (PrintAdaptiveSizePolicy) {
1.1114 + // A little more detail if Verbose is on
1.1115 + if (Verbose) {
1.1116 + gclog_or_tty->print( " avg_survived: %f"
1.1117 + " avg_deviation: %f",
1.1118 + _avg_survived->average(),
1.1119 + _avg_survived->deviation());
1.1120 + }
1.1121 +
1.1122 + gclog_or_tty->print( " avg_survived_padded_avg: %f",
1.1123 + _avg_survived->padded_average());
1.1124 +
1.1125 + if (Verbose) {
1.1126 + gclog_or_tty->print( " avg_promoted_avg: %f"
1.1127 + " avg_promoted_dev: %f",
1.1128 + avg_promoted()->average(),
1.1129 + avg_promoted()->deviation());
1.1130 + }
1.1131 +
1.1132 + gclog_or_tty->print( " avg_promoted_padded_avg: %f"
1.1133 + " avg_pretenured_padded_avg: %f"
1.1134 + " tenuring_thresh: %d"
1.1135 + " target_size: " SIZE_FORMAT,
1.1136 + avg_promoted()->padded_average(),
1.1137 + _avg_pretenured->padded_average(),
1.1138 + tenuring_threshold, target_size);
1.1139 + tty->cr();
1.1140 + }
1.1141 +
1.1142 + set_survivor_size(target_size);
1.1143 +
1.1144 + return tenuring_threshold;
1.1145 +}
1.1146 +
1.1147 +void PSAdaptiveSizePolicy::update_averages(bool is_survivor_overflow,
1.1148 + size_t survived,
1.1149 + size_t promoted) {
1.1150 + // Update averages
1.1151 + if (!is_survivor_overflow) {
1.1152 + // Keep running averages on how much survived
1.1153 + _avg_survived->sample(survived);
1.1154 + } else {
1.1155 + size_t survived_guess = survived + promoted;
1.1156 + _avg_survived->sample(survived_guess);
1.1157 + }
1.1158 + avg_promoted()->sample(promoted + _avg_pretenured->padded_average());
1.1159 +
1.1160 + if (PrintAdaptiveSizePolicy) {
1.1161 + gclog_or_tty->print(
1.1162 + "AdaptiveSizePolicy::compute_survivor_space_size_and_thresh:"
1.1163 + " survived: " SIZE_FORMAT
1.1164 + " promoted: " SIZE_FORMAT
1.1165 + " overflow: %s",
1.1166 + survived, promoted, is_survivor_overflow ? "true" : "false");
1.1167 + }
1.1168 +}
1.1169 +
1.1170 +bool PSAdaptiveSizePolicy::print_adaptive_size_policy_on(outputStream* st)
1.1171 + const {
1.1172 +
1.1173 + if (!UseAdaptiveSizePolicy) return false;
1.1174 +
1.1175 + return AdaptiveSizePolicy::print_adaptive_size_policy_on(
1.1176 + st,
1.1177 + PSScavenge::tenuring_threshold());
1.1178 +}
