--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1175 @@
+/*
+ * Copyright 2002-2007 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_psAdaptiveSizePolicy.cpp.incl"
+
+#include <math.h>
+
+PSAdaptiveSizePolicy::PSAdaptiveSizePolicy(size_t init_eden_size,
+ size_t init_promo_size,
+ size_t init_survivor_size,
+ size_t intra_generation_alignment,
+ double gc_pause_goal_sec,
+ double gc_minor_pause_goal_sec,
+ uint gc_cost_ratio) :
+ AdaptiveSizePolicy(init_eden_size,
+ init_promo_size,
+ init_survivor_size,
+ gc_pause_goal_sec,
+ gc_cost_ratio),
+ _collection_cost_margin_fraction(AdaptiveSizePolicyCollectionCostMargin/
+ 100.0),
+ _intra_generation_alignment(intra_generation_alignment),
+ _live_at_last_full_gc(init_promo_size),
+ _gc_minor_pause_goal_sec(gc_minor_pause_goal_sec),
+ _latest_major_mutator_interval_seconds(0),
+ _young_gen_change_for_major_pause_count(0)
+{
+ // Sizing policy statistics
+ _avg_major_pause =
+ new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding);
+ _avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
+ _avg_major_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
+
+ _avg_base_footprint = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight);
+ _major_pause_old_estimator =
+ new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
+ _major_pause_young_estimator =
+ new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
+ _major_collection_estimator =
+ new LinearLeastSquareFit(AdaptiveSizePolicyWeight);
+
+ _young_gen_size_increment_supplement = YoungGenerationSizeSupplement;
+ _old_gen_size_increment_supplement = TenuredGenerationSizeSupplement;
+
+ // Start the timers
+ _major_timer.start();
+
+ _old_gen_policy_is_ready = false;
+}
+
+void PSAdaptiveSizePolicy::major_collection_begin() {
+ // Update the interval time
+ _major_timer.stop();
+ // Save most recent collection time
+ _latest_major_mutator_interval_seconds = _major_timer.seconds();
+ _major_timer.reset();
+ _major_timer.start();
+}
+
+void PSAdaptiveSizePolicy::update_minor_pause_old_estimator(
+ double minor_pause_in_ms) {
+ double promo_size_in_mbytes = ((double)_promo_size)/((double)M);
+ _minor_pause_old_estimator->update(promo_size_in_mbytes,
+ minor_pause_in_ms);
+}
+
+void PSAdaptiveSizePolicy::major_collection_end(size_t amount_live,
+ GCCause::Cause gc_cause) {
+ // Update the pause time.
+ _major_timer.stop();
+
+ if (gc_cause != GCCause::_java_lang_system_gc ||
+ UseAdaptiveSizePolicyWithSystemGC) {
+ double major_pause_in_seconds = _major_timer.seconds();
+ double major_pause_in_ms = major_pause_in_seconds * MILLIUNITS;
+
+ // Sample for performance counter
+ _avg_major_pause->sample(major_pause_in_seconds);
+
+ // Cost of collection (unit-less)
+ double collection_cost = 0.0;
+ if ((_latest_major_mutator_interval_seconds > 0.0) &&
+ (major_pause_in_seconds > 0.0)) {
+ double interval_in_seconds =
+ _latest_major_mutator_interval_seconds + major_pause_in_seconds;
+ collection_cost =
+ major_pause_in_seconds / interval_in_seconds;
+ avg_major_gc_cost()->sample(collection_cost);
+
+ // Sample for performance counter
+ _avg_major_interval->sample(interval_in_seconds);
+ }
+
+ // Calculate variables used to estimate pause time vs. gen sizes
+ double eden_size_in_mbytes = ((double)_eden_size)/((double)M);
+ double promo_size_in_mbytes = ((double)_promo_size)/((double)M);
+ _major_pause_old_estimator->update(promo_size_in_mbytes,
+ major_pause_in_ms);
+ _major_pause_young_estimator->update(eden_size_in_mbytes,
+ major_pause_in_ms);
+
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print("psAdaptiveSizePolicy::major_collection_end: "
+ "major gc cost: %f average: %f", collection_cost,
+ avg_major_gc_cost()->average());
+ gclog_or_tty->print_cr(" major pause: %f major period %f",
+ major_pause_in_ms,
+ _latest_major_mutator_interval_seconds * MILLIUNITS);
+ }
+
+ // Calculate variable used to estimate collection cost vs. gen sizes
+ assert(collection_cost >= 0.0, "Expected to be non-negative");
+ _major_collection_estimator->update(promo_size_in_mbytes,
+ collection_cost);
+ }
+
+ // Update the amount live at the end of a full GC
+ _live_at_last_full_gc = amount_live;
+
+ // The policy does not have enough data until at least some major collections
+ // have been done.
+ if (_avg_major_pause->count() >= AdaptiveSizePolicyReadyThreshold) {
+ _old_gen_policy_is_ready = true;
+ }
+
+ // Interval times use this timer to measure the interval that
+ // the mutator runs. Reset after the GC pause has been measured.
+ _major_timer.reset();
+ _major_timer.start();
+}
+
+// If the remaining free space in the old generation is less that
+// that expected to be needed by the next collection, do a full
+// collection now.
+bool PSAdaptiveSizePolicy::should_full_GC(size_t old_free_in_bytes) {
+
+ // A similar test is done in the scavenge's should_attempt_scavenge(). If
+ // this is changed, decide if that test should also be changed.
+ bool result = padded_average_promoted_in_bytes() > (float) old_free_in_bytes;
+ if (PrintGCDetails && Verbose) {
+ if (result) {
+ gclog_or_tty->print(" full after scavenge: ");
+ } else {
+ gclog_or_tty->print(" no full after scavenge: ");
+ }
+ gclog_or_tty->print_cr(" average_promoted " SIZE_FORMAT
+ " padded_average_promoted " SIZE_FORMAT
+ " free in old gen " SIZE_FORMAT,
+ (size_t) average_promoted_in_bytes(),
+ (size_t) padded_average_promoted_in_bytes(),
+ old_free_in_bytes);
+ }
+ return result;
+}
+
+void PSAdaptiveSizePolicy::clear_generation_free_space_flags() {
+
+ AdaptiveSizePolicy::clear_generation_free_space_flags();
+
+ set_change_old_gen_for_min_pauses(0);
+
+ set_change_young_gen_for_maj_pauses(0);
+}
+
+
+// If this is not a full GC, only test and modify the young generation.
+
+void PSAdaptiveSizePolicy::compute_generation_free_space(size_t young_live,
+ size_t eden_live,
+ size_t old_live,
+ size_t perm_live,
+ size_t cur_eden,
+ size_t max_old_gen_size,
+ size_t max_eden_size,
+ bool is_full_gc,
+ GCCause::Cause gc_cause) {
+
+ // Update statistics
+ // Time statistics are updated as we go, update footprint stats here
+ _avg_base_footprint->sample(BaseFootPrintEstimate + perm_live);
+ avg_young_live()->sample(young_live);
+ avg_eden_live()->sample(eden_live);
+ if (is_full_gc) {
+ // old_live is only accurate after a full gc
+ avg_old_live()->sample(old_live);
+ }
+
+ // This code used to return if the policy was not ready , i.e.,
+ // policy_is_ready() returning false. The intent was that
+ // decisions below needed major collection times and so could
+ // not be made before two major collections. A consequence was
+ // adjustments to the young generation were not done until after
+ // two major collections even if the minor collections times
+ // exceeded the requested goals. Now let the young generation
+ // adjust for the minor collection times. Major collection times
+ // will be zero for the first collection and will naturally be
+ // ignored. Tenured generation adjustments are only made at the
+ // full collections so until the second major collection has
+ // been reached, no tenured generation adjustments will be made.
+
+ // Until we know better, desired promotion size uses the last calculation
+ size_t desired_promo_size = _promo_size;
+
+ // Start eden at the current value. The desired value that is stored
+ // in _eden_size is not bounded by constraints of the heap and can
+ // run away.
+ //
+ // As expected setting desired_eden_size to the current
+ // value of desired_eden_size as a starting point
+ // caused desired_eden_size to grow way too large and caused
+ // an overflow down stream. It may have improved performance in
+ // some case but is dangerous.
+ size_t desired_eden_size = cur_eden;
+
+#ifdef ASSERT
+ size_t original_promo_size = desired_promo_size;
+ size_t original_eden_size = desired_eden_size;
+#endif
+
+ // Cache some values. There's a bit of work getting these, so
+ // we might save a little time.
+ const double major_cost = major_gc_cost();
+ const double minor_cost = minor_gc_cost();
+
+ // Used for diagnostics
+ clear_generation_free_space_flags();
+
+ // Limits on our growth
+ size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average());
+
+ // This method sets the desired eden size. That plus the
+ // desired survivor space sizes sets the desired young generation
+ // size. This methods does not know what the desired survivor
+ // size is but expects that other policy will attempt to make
+ // the survivor sizes compatible with the live data in the
+ // young generation. This limit is an estimate of the space left
+ // in the young generation after the survivor spaces have been
+ // subtracted out.
+ size_t eden_limit = max_eden_size;
+
+ // But don't force a promo size below the current promo size. Otherwise,
+ // the promo size will shrink for no good reason.
+ promo_limit = MAX2(promo_limit, _promo_size);
+
+ const double gc_cost_limit = GCTimeLimit/100.0;
+
+ // Which way should we go?
+ // if pause requirement is not met
+ // adjust size of any generation with average paus exceeding
+ // the pause limit. Adjust one pause at a time (the larger)
+ // and only make adjustments for the major pause at full collections.
+ // else if throughput requirement not met
+ // adjust the size of the generation with larger gc time. Only
+ // adjust one generation at a time.
+ // else
+ // adjust down the total heap size. Adjust down the larger of the
+ // generations.
+
+ // Add some checks for a threshhold for a change. For example,
+ // a change less than the necessary alignment is probably not worth
+ // attempting.
+
+
+ if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) ||
+ (_avg_major_pause->padded_average() > gc_pause_goal_sec())) {
+ //
+ // Check pauses
+ //
+ // Make changes only to affect one of the pauses (the larger)
+ // at a time.
+ adjust_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size);
+
+ } else if (_avg_minor_pause->padded_average() > gc_minor_pause_goal_sec()) {
+ // Adjust only for the minor pause time goal
+ adjust_for_minor_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size);
+
+ } else if(adjusted_mutator_cost() < _throughput_goal) {
+ // This branch used to require that (mutator_cost() > 0.0 in 1.4.2.
+ // This sometimes resulted in skipping to the minimize footprint
+ // code. Change this to try and reduce GC time if mutator time is
+ // negative for whatever reason. Or for future consideration,
+ // bail out of the code if mutator time is negative.
+ //
+ // Throughput
+ //
+ assert(major_cost >= 0.0, "major cost is < 0.0");
+ assert(minor_cost >= 0.0, "minor cost is < 0.0");
+ // Try to reduce the GC times.
+ adjust_for_throughput(is_full_gc, &desired_promo_size, &desired_eden_size);
+
+ } else {
+
+ // Be conservative about reducing the footprint.
+ // Do a minimum number of major collections first.
+ // Have reasonable averages for major and minor collections costs.
+ if (UseAdaptiveSizePolicyFootprintGoal &&
+ young_gen_policy_is_ready() &&
+ avg_major_gc_cost()->average() >= 0.0 &&
+ avg_minor_gc_cost()->average() >= 0.0) {
+ size_t desired_sum = desired_eden_size + desired_promo_size;
+ desired_eden_size = adjust_eden_for_footprint(desired_eden_size,
+ desired_sum);
+ if (is_full_gc) {
+ set_decide_at_full_gc(decide_at_full_gc_true);
+ desired_promo_size = adjust_promo_for_footprint(desired_promo_size,
+ desired_sum);
+ }
+ }
+ }
+
+ // Note we make the same tests as in the code block below; the code
+ // seems a little easier to read with the printing in another block.
+ if (PrintAdaptiveSizePolicy) {
+ if (desired_promo_size > promo_limit) {
+ // "free_in_old_gen" was the original value for used for promo_limit
+ size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
+ gclog_or_tty->print_cr(
+ "PSAdaptiveSizePolicy::compute_generation_free_space limits:"
+ " desired_promo_size: " SIZE_FORMAT
+ " promo_limit: " SIZE_FORMAT
+ " free_in_old_gen: " SIZE_FORMAT
+ " max_old_gen_size: " SIZE_FORMAT
+ " avg_old_live: " SIZE_FORMAT,
+ desired_promo_size, promo_limit, free_in_old_gen,
+ max_old_gen_size, (size_t) avg_old_live()->average());
+ }
+ if (desired_eden_size > eden_limit) {
+ gclog_or_tty->print_cr(
+ "AdaptiveSizePolicy::compute_generation_free_space limits:"
+ " desired_eden_size: " SIZE_FORMAT
+ " old_eden_size: " SIZE_FORMAT
+ " eden_limit: " SIZE_FORMAT
+ " cur_eden: " SIZE_FORMAT
+ " max_eden_size: " SIZE_FORMAT
+ " avg_young_live: " SIZE_FORMAT,
+ desired_eden_size, _eden_size, eden_limit, cur_eden,
+ max_eden_size, (size_t)avg_young_live()->average());
+ }
+ if (gc_cost() > gc_cost_limit) {
+ gclog_or_tty->print_cr(
+ "AdaptiveSizePolicy::compute_generation_free_space: gc time limit"
+ " gc_cost: %f "
+ " GCTimeLimit: %d",
+ gc_cost(), GCTimeLimit);
+ }
+ }
+
+ // Align everything and make a final limit check
+ const size_t alignment = _intra_generation_alignment;
+ desired_eden_size = align_size_up(desired_eden_size, alignment);
+ desired_eden_size = MAX2(desired_eden_size, alignment);
+ desired_promo_size = align_size_up(desired_promo_size, alignment);
+ desired_promo_size = MAX2(desired_promo_size, alignment);
+
+ eden_limit = align_size_down(eden_limit, alignment);
+ promo_limit = align_size_down(promo_limit, alignment);
+
+ // Is too much time being spent in GC?
+ // Is the heap trying to grow beyond it's limits?
+
+ const size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
+ if (desired_promo_size > free_in_old_gen && desired_eden_size > eden_limit) {
+
+ // eden_limit is the upper limit on the size of eden based on
+ // the maximum size of the young generation and the sizes
+ // of the survivor space.
+ // The question being asked is whether the gc costs are high
+ // and the space being recovered by a collection is low.
+ // free_in_young_gen is the free space in the young generation
+ // after a collection and promo_live is the free space in the old
+ // generation after a collection.
+ //
+ // Use the minimum of the current value of the live in the
+ // young gen or the average of the live in the young gen.
+ // If the current value drops quickly, that should be taken
+ // into account (i.e., don't trigger if the amount of free
+ // space has suddenly jumped up). If the current is much
+ // higher than the average, use the average since it represents
+ // the longer term behavor.
+ const size_t live_in_eden = MIN2(eden_live, (size_t) avg_eden_live()->average());
+ const size_t free_in_eden = eden_limit > live_in_eden ?
+ eden_limit - live_in_eden : 0;
+ const size_t total_free_limit = free_in_old_gen + free_in_eden;
+ const size_t total_mem = max_old_gen_size + max_eden_size;
+ const double mem_free_limit = total_mem * (GCHeapFreeLimit/100.0);
+ if (PrintAdaptiveSizePolicy && (Verbose ||
+ (total_free_limit < (size_t) mem_free_limit))) {
+ gclog_or_tty->print_cr(
+ "PSAdaptiveSizePolicy::compute_generation_free_space limits:"
+ " promo_limit: " SIZE_FORMAT
+ " eden_limit: " SIZE_FORMAT
+ " total_free_limit: " SIZE_FORMAT
+ " max_old_gen_size: " SIZE_FORMAT
+ " max_eden_size: " SIZE_FORMAT
+ " mem_free_limit: " SIZE_FORMAT,
+ promo_limit, eden_limit, total_free_limit,
+ max_old_gen_size, max_eden_size,
+ (size_t) mem_free_limit);
+ }
+
+ if (is_full_gc) {
+ if (gc_cost() > gc_cost_limit &&
+ total_free_limit < (size_t) mem_free_limit) {
+ // Collections, on average, are taking too much time, and
+ // gc_cost() > gc_cost_limit
+ // we have too little space available after a full gc.
+ // total_free_limit < mem_free_limit
+ // where
+ // total_free_limit is the free space available in
+ // both generations
+ // total_mem is the total space available for allocation
+ // in both generations (survivor spaces are not included
+ // just as they are not included in eden_limit).
+ // mem_free_limit is a fraction of total_mem judged to be an
+ // acceptable amount that is still unused.
+ // The heap can ask for the value of this variable when deciding
+ // whether to thrown an OutOfMemory error.
+ // Note that the gc time limit test only works for the collections
+ // of the young gen + tenured gen and not for collections of the
+ // permanent gen. That is because the calculation of the space
+ // freed by the collection is the free space in the young gen +
+ // tenured gen.
+ // Ignore explicit GC's. Ignoring explicit GC's at this level
+ // is the equivalent of the GC did not happen as far as the
+ // overhead calculation is concerted (i.e., the flag is not set
+ // and the count is not affected). Also the average will not
+ // have been updated unless UseAdaptiveSizePolicyWithSystemGC is on.
+ if (!GCCause::is_user_requested_gc(gc_cause) &&
+ !GCCause::is_serviceability_requested_gc(gc_cause)) {
+ inc_gc_time_limit_count();
+ if (UseGCOverheadLimit &&
+ (gc_time_limit_count() > AdaptiveSizePolicyGCTimeLimitThreshold)){
+ // All conditions have been met for throwing an out-of-memory
+ _gc_time_limit_exceeded = true;
+ // Avoid consecutive OOM due to the gc time limit by resetting
+ // the counter.
+ reset_gc_time_limit_count();
+ }
+ _print_gc_time_limit_would_be_exceeded = true;
+ }
+ } else {
+ // Did not exceed overhead limits
+ reset_gc_time_limit_count();
+ }
+ }
+ }
+
+
+ // And one last limit check, now that we've aligned things.
+ if (desired_eden_size > eden_limit) {
+ // If the policy says to get a larger eden but
+ // is hitting the limit, don't decrease eden.
+ // This can lead to a general drifting down of the
+ // eden size. Let the tenuring calculation push more
+ // into the old gen.
+ desired_eden_size = MAX2(eden_limit, cur_eden);
+ }
+ desired_promo_size = MIN2(desired_promo_size, promo_limit);
+
+
+ if (PrintAdaptiveSizePolicy) {
+ // Timing stats
+ gclog_or_tty->print(
+ "PSAdaptiveSizePolicy::compute_generation_free_space: costs"
+ " minor_time: %f"
+ " major_cost: %f"
+ " mutator_cost: %f"
+ " throughput_goal: %f",
+ minor_gc_cost(), major_gc_cost(), mutator_cost(),
+ _throughput_goal);
+
+ // We give more details if Verbose is set
+ if (Verbose) {
+ gclog_or_tty->print( " minor_pause: %f"
+ " major_pause: %f"
+ " minor_interval: %f"
+ " major_interval: %f"
+ " pause_goal: %f",
+ _avg_minor_pause->padded_average(),
+ _avg_major_pause->padded_average(),
+ _avg_minor_interval->average(),
+ _avg_major_interval->average(),
+ gc_pause_goal_sec());
+ }
+
+ // Footprint stats
+ gclog_or_tty->print( " live_space: " SIZE_FORMAT
+ " free_space: " SIZE_FORMAT,
+ live_space(), free_space());
+ // More detail
+ if (Verbose) {
+ gclog_or_tty->print( " base_footprint: " SIZE_FORMAT
+ " avg_young_live: " SIZE_FORMAT
+ " avg_old_live: " SIZE_FORMAT,
+ (size_t)_avg_base_footprint->average(),
+ (size_t)avg_young_live()->average(),
+ (size_t)avg_old_live()->average());
+ }
+
+ // And finally, our old and new sizes.
+ gclog_or_tty->print(" old_promo_size: " SIZE_FORMAT
+ " old_eden_size: " SIZE_FORMAT
+ " desired_promo_size: " SIZE_FORMAT
+ " desired_eden_size: " SIZE_FORMAT,
+ _promo_size, _eden_size,
+ desired_promo_size, desired_eden_size);
+ gclog_or_tty->cr();
+ }
+
+ decay_supplemental_growth(is_full_gc);
+
+ set_promo_size(desired_promo_size);
+ set_eden_size(desired_eden_size);
+};
+
+void PSAdaptiveSizePolicy::decay_supplemental_growth(bool is_full_gc) {
+ // Decay the supplemental increment? Decay the supplement growth
+ // factor even if it is not used. It is only meant to give a boost
+ // to the initial growth and if it is not used, then it was not
+ // needed.
+ if (is_full_gc) {
+ // Don't wait for the threshold value for the major collections. If
+ // here, the supplemental growth term was used and should decay.
+ if ((_avg_major_pause->count() % TenuredGenerationSizeSupplementDecay)
+ == 0) {
+ _old_gen_size_increment_supplement =
+ _old_gen_size_increment_supplement >> 1;
+ }
+ } else {
+ if ((_avg_minor_pause->count() >= AdaptiveSizePolicyReadyThreshold) &&
+ (_avg_minor_pause->count() % YoungGenerationSizeSupplementDecay) == 0) {
+ _young_gen_size_increment_supplement =
+ _young_gen_size_increment_supplement >> 1;
+ }
+ }
+}
+
+void PSAdaptiveSizePolicy::adjust_for_minor_pause_time(bool is_full_gc,
+ size_t* desired_promo_size_ptr, size_t* desired_eden_size_ptr) {
+
+ // Adjust the young generation size to reduce pause time of
+ // of collections.
+ //
+ // The AdaptiveSizePolicyInitializingSteps test is not used
+ // here. It has not seemed to be needed but perhaps should
+ // be added for consistency.
+ if (minor_pause_young_estimator()->decrement_will_decrease()) {
+ // reduce eden size
+ set_change_young_gen_for_min_pauses(
+ decrease_young_gen_for_min_pauses_true);
+ *desired_eden_size_ptr = *desired_eden_size_ptr -
+ eden_decrement_aligned_down(*desired_eden_size_ptr);
+ } else {
+ // EXPERIMENTAL ADJUSTMENT
+ // Only record that the estimator indicated such an action.
+ // *desired_eden_size_ptr = *desired_eden_size_ptr + eden_heap_delta;
+ set_change_young_gen_for_min_pauses(
+ increase_young_gen_for_min_pauses_true);
+ }
+ if (PSAdjustTenuredGenForMinorPause) {
+ // If the desired eden size is as small as it will get,
+ // try to adjust the old gen size.
+ if (*desired_eden_size_ptr <= _intra_generation_alignment) {
+ // Vary the old gen size to reduce the young gen pause. This
+ // may not be a good idea. This is just a test.
+ if (minor_pause_old_estimator()->decrement_will_decrease()) {
+ set_change_old_gen_for_min_pauses(
+ decrease_old_gen_for_min_pauses_true);
+ *desired_promo_size_ptr =
+ _promo_size - promo_decrement_aligned_down(*desired_promo_size_ptr);
+ } else {
+ set_change_old_gen_for_min_pauses(
+ increase_old_gen_for_min_pauses_true);
+ size_t promo_heap_delta =
+ promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
+ if ((*desired_promo_size_ptr + promo_heap_delta) >
+ *desired_promo_size_ptr) {
+ *desired_promo_size_ptr =
+ _promo_size + promo_heap_delta;
+ }
+ }
+ }
+ }
+}
+
+void PSAdaptiveSizePolicy::adjust_for_pause_time(bool is_full_gc,
+ size_t* desired_promo_size_ptr,
+ size_t* desired_eden_size_ptr) {
+
+ size_t promo_heap_delta = 0;
+ size_t eden_heap_delta = 0;
+ // Add some checks for a threshhold for a change. For example,
+ // a change less than the required alignment is probably not worth
+ // attempting.
+ if (is_full_gc) {
+ set_decide_at_full_gc(decide_at_full_gc_true);
+ }
+
+ if (_avg_minor_pause->padded_average() > _avg_major_pause->padded_average()) {
+ adjust_for_minor_pause_time(is_full_gc,
+ desired_promo_size_ptr,
+ desired_eden_size_ptr);
+ // major pause adjustments
+ } else if (is_full_gc) {
+ // Adjust for the major pause time only at full gc's because the
+ // affects of a change can only be seen at full gc's.
+
+ // Reduce old generation size to reduce pause?
+ if (major_pause_old_estimator()->decrement_will_decrease()) {
+ // reduce old generation size
+ set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true);
+ promo_heap_delta = promo_decrement_aligned_down(*desired_promo_size_ptr);
+ *desired_promo_size_ptr = _promo_size - promo_heap_delta;
+ } else {
+ // EXPERIMENTAL ADJUSTMENT
+ // Only record that the estimator indicated such an action.
+ // *desired_promo_size_ptr = _promo_size +
+ // promo_increment_aligned_up(*desired_promo_size_ptr);
+ set_change_old_gen_for_maj_pauses(increase_old_gen_for_maj_pauses_true);
+ }
+ if (PSAdjustYoungGenForMajorPause) {
+ // If the promo size is at the minimum (i.e., the old gen
+ // size will not actually decrease), consider changing the
+ // young gen size.
+ if (*desired_promo_size_ptr < _intra_generation_alignment) {
+ // If increasing the young generation will decrease the old gen
+ // pause, do it.
+ // During startup there is noise in the statistics for deciding
+ // on whether to increase or decrease the young gen size. For
+ // some number of iterations, just try to increase the young
+ // gen size if the major pause is too long to try and establish
+ // good statistics for later decisions.
+ if (major_pause_young_estimator()->increment_will_decrease() ||
+ (_young_gen_change_for_major_pause_count
+ <= AdaptiveSizePolicyInitializingSteps)) {
+ set_change_young_gen_for_maj_pauses(
+ increase_young_gen_for_maj_pauses_true);
+ eden_heap_delta = eden_increment_aligned_up(*desired_eden_size_ptr);
+ *desired_eden_size_ptr = _eden_size + eden_heap_delta;
+ _young_gen_change_for_major_pause_count++;
+ } else {
+ // Record that decreasing the young gen size would decrease
+ // the major pause
+ set_change_young_gen_for_maj_pauses(
+ decrease_young_gen_for_maj_pauses_true);
+ eden_heap_delta = eden_decrement_aligned_down(*desired_eden_size_ptr);
+ *desired_eden_size_ptr = _eden_size - eden_heap_delta;
+ }
+ }
+ }
+ }
+
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(
+ "AdaptiveSizePolicy::compute_generation_free_space "
+ "adjusting gen sizes for major pause (avg %f goal %f). "
+ "desired_promo_size " SIZE_FORMAT "desired_eden_size "
+ SIZE_FORMAT
+ " promo delta " SIZE_FORMAT " eden delta " SIZE_FORMAT,
+ _avg_major_pause->average(), gc_pause_goal_sec(),
+ *desired_promo_size_ptr, *desired_eden_size_ptr,
+ promo_heap_delta, eden_heap_delta);
+ }
+}
+
+void PSAdaptiveSizePolicy::adjust_for_throughput(bool is_full_gc,
+ size_t* desired_promo_size_ptr,
+ size_t* desired_eden_size_ptr) {
+
+ // Add some checks for a threshhold for a change. For example,
+ // a change less than the required alignment is probably not worth
+ // attempting.
+ if (is_full_gc) {
+ set_decide_at_full_gc(decide_at_full_gc_true);
+ }
+
+ if ((gc_cost() + mutator_cost()) == 0.0) {
+ return;
+ }
+
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print("\nPSAdaptiveSizePolicy::adjust_for_throughput("
+ "is_full: %d, promo: " SIZE_FORMAT ", cur_eden: " SIZE_FORMAT "): ",
+ is_full_gc, *desired_promo_size_ptr, *desired_eden_size_ptr);
+ gclog_or_tty->print_cr("mutator_cost %f major_gc_cost %f "
+ "minor_gc_cost %f", mutator_cost(), major_gc_cost(), minor_gc_cost());
+ }
+
+ // Tenured generation
+ if (is_full_gc) {
+
+ // Calculate the change to use for the tenured gen.
+ size_t scaled_promo_heap_delta = 0;
+ // Can the increment to the generation be scaled?
+ if (gc_cost() >= 0.0 && major_gc_cost() >= 0.0) {
+ size_t promo_heap_delta =
+ promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
+ double scale_by_ratio = major_gc_cost() / gc_cost();
+ scaled_promo_heap_delta =
+ (size_t) (scale_by_ratio * (double) promo_heap_delta);
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(
+ "Scaled tenured increment: " SIZE_FORMAT " by %f down to "
+ SIZE_FORMAT,
+ promo_heap_delta, scale_by_ratio, scaled_promo_heap_delta);
+ }
+ } else if (major_gc_cost() >= 0.0) {
+ // Scaling is not going to work. If the major gc time is the
+ // larger, give it a full increment.
+ if (major_gc_cost() >= minor_gc_cost()) {
+ scaled_promo_heap_delta =
+ promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr);
+ }
+ } else {
+ // Don't expect to get here but it's ok if it does
+ // in the product build since the delta will be 0
+ // and nothing will change.
+ assert(false, "Unexpected value for gc costs");
+ }
+
+ switch (AdaptiveSizeThroughPutPolicy) {
+ case 1:
+ // Early in the run the statistics might not be good. Until
+ // a specific number of collections have been, use the heuristic
+ // that a larger generation size means lower collection costs.
+ if (major_collection_estimator()->increment_will_decrease() ||
+ (_old_gen_change_for_major_throughput
+ <= AdaptiveSizePolicyInitializingSteps)) {
+ // Increase tenured generation size to reduce major collection cost
+ if ((*desired_promo_size_ptr + scaled_promo_heap_delta) >
+ *desired_promo_size_ptr) {
+ *desired_promo_size_ptr = _promo_size + scaled_promo_heap_delta;
+ }
+ set_change_old_gen_for_throughput(
+ increase_old_gen_for_throughput_true);
+ _old_gen_change_for_major_throughput++;
+ } else {
+ // EXPERIMENTAL ADJUSTMENT
+ // Record that decreasing the old gen size would decrease
+ // the major collection cost but don't do it.
+ // *desired_promo_size_ptr = _promo_size -
+ // promo_decrement_aligned_down(*desired_promo_size_ptr);
+ set_change_old_gen_for_throughput(
+ decrease_old_gen_for_throughput_true);
+ }
+
+ break;
+ default:
+ // Simplest strategy
+ if ((*desired_promo_size_ptr + scaled_promo_heap_delta) >
+ *desired_promo_size_ptr) {
+ *desired_promo_size_ptr = *desired_promo_size_ptr +
+ scaled_promo_heap_delta;
+ }
+ set_change_old_gen_for_throughput(
+ increase_old_gen_for_throughput_true);
+ _old_gen_change_for_major_throughput++;
+ }
+
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(
+ "adjusting tenured gen for throughput (avg %f goal %f). "
+ "desired_promo_size " SIZE_FORMAT " promo_delta " SIZE_FORMAT ,
+ mutator_cost(), _throughput_goal,
+ *desired_promo_size_ptr, scaled_promo_heap_delta);
+ }
+ }
+
+ // Young generation
+ size_t scaled_eden_heap_delta = 0;
+ // Can the increment to the generation be scaled?
+ if (gc_cost() >= 0.0 && minor_gc_cost() >= 0.0) {
+ size_t eden_heap_delta =
+ eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr);
+ double scale_by_ratio = minor_gc_cost() / gc_cost();
+ assert(scale_by_ratio <= 1.0 && scale_by_ratio >= 0.0, "Scaling is wrong");
+ scaled_eden_heap_delta =
+ (size_t) (scale_by_ratio * (double) eden_heap_delta);
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(
+ "Scaled eden increment: " SIZE_FORMAT " by %f down to "
+ SIZE_FORMAT,
+ eden_heap_delta, scale_by_ratio, scaled_eden_heap_delta);
+ }
+ } else if (minor_gc_cost() >= 0.0) {
+ // Scaling is not going to work. If the minor gc time is the
+ // larger, give it a full increment.
+ if (minor_gc_cost() > major_gc_cost()) {
+ scaled_eden_heap_delta =
+ eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr);
+ }
+ } else {
+ // Don't expect to get here but it's ok if it does
+ // in the product build since the delta will be 0
+ // and nothing will change.
+ assert(false, "Unexpected value for gc costs");
+ }
+
+ // Use a heuristic for some number of collections to give
+ // the averages time to settle down.
+ switch (AdaptiveSizeThroughPutPolicy) {
+ case 1:
+ if (minor_collection_estimator()->increment_will_decrease() ||
+ (_young_gen_change_for_minor_throughput
+ <= AdaptiveSizePolicyInitializingSteps)) {
+ // Expand young generation size to reduce frequency of
+ // of collections.
+ if ((*desired_eden_size_ptr + scaled_eden_heap_delta) >
+ *desired_eden_size_ptr) {
+ *desired_eden_size_ptr =
+ *desired_eden_size_ptr + scaled_eden_heap_delta;
+ }
+ set_change_young_gen_for_throughput(
+ increase_young_gen_for_througput_true);
+ _young_gen_change_for_minor_throughput++;
+ } else {
+ // EXPERIMENTAL ADJUSTMENT
+ // Record that decreasing the young gen size would decrease
+ // the minor collection cost but don't do it.
+ // *desired_eden_size_ptr = _eden_size -
+ // eden_decrement_aligned_down(*desired_eden_size_ptr);
+ set_change_young_gen_for_throughput(
+ decrease_young_gen_for_througput_true);
+ }
+ break;
+ default:
+ if ((*desired_eden_size_ptr + scaled_eden_heap_delta) >
+ *desired_eden_size_ptr) {
+ *desired_eden_size_ptr =
+ *desired_eden_size_ptr + scaled_eden_heap_delta;
+ }
+ set_change_young_gen_for_throughput(
+ increase_young_gen_for_througput_true);
+ _young_gen_change_for_minor_throughput++;
+ }
+
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(
+ "adjusting eden for throughput (avg %f goal %f). desired_eden_size "
+ SIZE_FORMAT " eden delta " SIZE_FORMAT "\n",
+ mutator_cost(), _throughput_goal,
+ *desired_eden_size_ptr, scaled_eden_heap_delta);
+ }
+}
+
+size_t PSAdaptiveSizePolicy::adjust_promo_for_footprint(
+ size_t desired_promo_size, size_t desired_sum) {
+ assert(desired_promo_size <= desired_sum, "Inconsistent parameters");
+ set_decrease_for_footprint(decrease_old_gen_for_footprint_true);
+
+ size_t change = promo_decrement(desired_promo_size);
+ change = scale_down(change, desired_promo_size, desired_sum);
+
+ size_t reduced_size = desired_promo_size - change;
+
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(
+ "AdaptiveSizePolicy::compute_generation_free_space "
+ "adjusting tenured gen for footprint. "
+ "starting promo size " SIZE_FORMAT
+ " reduced promo size " SIZE_FORMAT,
+ " promo delta " SIZE_FORMAT,
+ desired_promo_size, reduced_size, change );
+ }
+
+ assert(reduced_size <= desired_promo_size, "Inconsistent result");
+ return reduced_size;
+}
+
+size_t PSAdaptiveSizePolicy::adjust_eden_for_footprint(
+ size_t desired_eden_size, size_t desired_sum) {
+ assert(desired_eden_size <= desired_sum, "Inconsistent parameters");
+ set_decrease_for_footprint(decrease_young_gen_for_footprint_true);
+
+ size_t change = eden_decrement(desired_eden_size);
+ change = scale_down(change, desired_eden_size, desired_sum);
+
+ size_t reduced_size = desired_eden_size - change;
+
+ if (PrintAdaptiveSizePolicy && Verbose) {
+ gclog_or_tty->print_cr(
+ "AdaptiveSizePolicy::compute_generation_free_space "
+ "adjusting eden for footprint. "
+ " starting eden size " SIZE_FORMAT
+ " reduced eden size " SIZE_FORMAT
+ " eden delta " SIZE_FORMAT,
+ desired_eden_size, reduced_size, change);
+ }
+
+ assert(reduced_size <= desired_eden_size, "Inconsistent result");
+ return reduced_size;
+}
+
+// Scale down "change" by the factor
+// part / total
+// Don't align the results.
+
+size_t PSAdaptiveSizePolicy::scale_down(size_t change,
+ double part,
+ double total) {
+ assert(part <= total, "Inconsistent input");
+ size_t reduced_change = change;
+ if (total > 0) {
+ double fraction = part / total;
+ reduced_change = (size_t) (fraction * (double) change);
+ }
+ assert(reduced_change <= change, "Inconsistent result");
+ return reduced_change;
+}
+
+size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden,
+ uint percent_change) {
+ size_t eden_heap_delta;
+ eden_heap_delta = cur_eden / 100 * percent_change;
+ return eden_heap_delta;
+}
+
+size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden) {
+ return eden_increment(cur_eden, YoungGenerationSizeIncrement);
+}
+
+size_t PSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) {
+ size_t result = eden_increment(cur_eden, YoungGenerationSizeIncrement);
+ return align_size_up(result, _intra_generation_alignment);
+}
+
+size_t PSAdaptiveSizePolicy::eden_increment_aligned_down(size_t cur_eden) {
+ size_t result = eden_increment(cur_eden);
+ return align_size_down(result, _intra_generation_alignment);
+}
+
+size_t PSAdaptiveSizePolicy::eden_increment_with_supplement_aligned_up(
+ size_t cur_eden) {
+ size_t result = eden_increment(cur_eden,
+ YoungGenerationSizeIncrement + _young_gen_size_increment_supplement);
+ return align_size_up(result, _intra_generation_alignment);
+}
+
+size_t PSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) {
+ size_t eden_heap_delta = eden_decrement(cur_eden);
+ return align_size_down(eden_heap_delta, _intra_generation_alignment);
+}
+
+size_t PSAdaptiveSizePolicy::eden_decrement(size_t cur_eden) {
+ size_t eden_heap_delta = eden_increment(cur_eden) /
+ AdaptiveSizeDecrementScaleFactor;
+ return eden_heap_delta;
+}
+
+size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo,
+ uint percent_change) {
+ size_t promo_heap_delta;
+ promo_heap_delta = cur_promo / 100 * percent_change;
+ return promo_heap_delta;
+}
+
+size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo) {
+ return promo_increment(cur_promo, TenuredGenerationSizeIncrement);
+}
+
+size_t PSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) {
+ size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement);
+ return align_size_up(result, _intra_generation_alignment);
+}
+
+size_t PSAdaptiveSizePolicy::promo_increment_aligned_down(size_t cur_promo) {
+ size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement);
+ return align_size_down(result, _intra_generation_alignment);
+}
+
+size_t PSAdaptiveSizePolicy::promo_increment_with_supplement_aligned_up(
+ size_t cur_promo) {
+ size_t result = promo_increment(cur_promo,
+ TenuredGenerationSizeIncrement + _old_gen_size_increment_supplement);
+ return align_size_up(result, _intra_generation_alignment);
+}
+
+size_t PSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) {
+ size_t promo_heap_delta = promo_decrement(cur_promo);
+ return align_size_down(promo_heap_delta, _intra_generation_alignment);
+}
+
+size_t PSAdaptiveSizePolicy::promo_decrement(size_t cur_promo) {
+ size_t promo_heap_delta = promo_increment(cur_promo);
+ promo_heap_delta = promo_heap_delta / AdaptiveSizeDecrementScaleFactor;
+ return promo_heap_delta;
+}
+
+int PSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold(
+ bool is_survivor_overflow,
+ int tenuring_threshold,
+ size_t survivor_limit) {
+ assert(survivor_limit >= _intra_generation_alignment,
+ "survivor_limit too small");
+ assert((size_t)align_size_down(survivor_limit, _intra_generation_alignment)
+ == survivor_limit, "survivor_limit not aligned");
+
+ // This method is called even if the tenuring threshold and survivor
+ // spaces are not adjusted so that the averages are sampled above.
+ if (!UsePSAdaptiveSurvivorSizePolicy ||
+ !young_gen_policy_is_ready()) {
+ return tenuring_threshold;
+ }
+
+ // We'll decide whether to increase or decrease the tenuring
+ // threshold based partly on the newly computed survivor size
+ // (if we hit the maximum limit allowed, we'll always choose to
+ // decrement the threshold).
+ bool incr_tenuring_threshold = false;
+ bool decr_tenuring_threshold = false;
+
+ set_decrement_tenuring_threshold_for_gc_cost(false);
+ set_increment_tenuring_threshold_for_gc_cost(false);
+ set_decrement_tenuring_threshold_for_survivor_limit(false);
+
+ if (!is_survivor_overflow) {
+ // Keep running averages on how much survived
+
+ // We use the tenuring threshold to equalize the cost of major
+ // and minor collections.
+ // ThresholdTolerance is used to indicate how sensitive the
+ // tenuring threshold is to differences in cost betweent the
+ // collection types.
+
+ // Get the times of interest. This involves a little work, so
+ // we cache the values here.
+ const double major_cost = major_gc_cost();
+ const double minor_cost = minor_gc_cost();
+
+ if (minor_cost > major_cost * _threshold_tolerance_percent) {
+ // Minor times are getting too long; lower the threshold so
+ // less survives and more is promoted.
+ decr_tenuring_threshold = true;
+ set_decrement_tenuring_threshold_for_gc_cost(true);
+ } else if (major_cost > minor_cost * _threshold_tolerance_percent) {
+ // Major times are too long, so we want less promotion.
+ incr_tenuring_threshold = true;
+ set_increment_tenuring_threshold_for_gc_cost(true);
+ }
+
+ } else {
+ // Survivor space overflow occurred, so promoted and survived are
+ // not accurate. We'll make our best guess by combining survived
+ // and promoted and count them as survivors.
+ //
+ // We'll lower the tenuring threshold to see if we can correct
+ // things. Also, set the survivor size conservatively. We're
+ // trying to avoid many overflows from occurring if defnew size
+ // is just too small.
+
+ decr_tenuring_threshold = true;
+ }
+
+ // The padded average also maintains a deviation from the average;
+ // we use this to see how good of an estimate we have of what survived.
+ // We're trying to pad the survivor size as little as possible without
+ // overflowing the survivor spaces.
+ size_t target_size = align_size_up((size_t)_avg_survived->padded_average(),
+ _intra_generation_alignment);
+ target_size = MAX2(target_size, _intra_generation_alignment);
+
+ if (target_size > survivor_limit) {
+ // Target size is bigger than we can handle. Let's also reduce
+ // the tenuring threshold.
+ target_size = survivor_limit;
+ decr_tenuring_threshold = true;
+ set_decrement_tenuring_threshold_for_survivor_limit(true);
+ }
+
+ // Finally, increment or decrement the tenuring threshold, as decided above.
+ // We test for decrementing first, as we might have hit the target size
+ // limit.
+ if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
+ if (tenuring_threshold > 1) {
+ tenuring_threshold--;
+ }
+ } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) {
+ if (tenuring_threshold < MaxTenuringThreshold) {
+ tenuring_threshold++;
+ }
+ }
+
+ // We keep a running average of the amount promoted which is used
+ // to decide when we should collect the old generation (when
+ // the amount of old gen free space is less than what we expect to
+ // promote).
+
+ if (PrintAdaptiveSizePolicy) {
+ // A little more detail if Verbose is on
+ if (Verbose) {
+ gclog_or_tty->print( " avg_survived: %f"
+ " avg_deviation: %f",
+ _avg_survived->average(),
+ _avg_survived->deviation());
+ }
+
+ gclog_or_tty->print( " avg_survived_padded_avg: %f",
+ _avg_survived->padded_average());
+
+ if (Verbose) {
+ gclog_or_tty->print( " avg_promoted_avg: %f"
+ " avg_promoted_dev: %f",
+ avg_promoted()->average(),
+ avg_promoted()->deviation());
+ }
+
+ gclog_or_tty->print( " avg_promoted_padded_avg: %f"
+ " avg_pretenured_padded_avg: %f"
+ " tenuring_thresh: %d"
+ " target_size: " SIZE_FORMAT,
+ avg_promoted()->padded_average(),
+ _avg_pretenured->padded_average(),
+ tenuring_threshold, target_size);
+ tty->cr();
+ }
+
+ set_survivor_size(target_size);
+
+ return tenuring_threshold;
+}
+
+void PSAdaptiveSizePolicy::update_averages(bool is_survivor_overflow,
+ size_t survived,
+ size_t promoted) {
+ // Update averages
+ if (!is_survivor_overflow) {
+ // Keep running averages on how much survived
+ _avg_survived->sample(survived);
+ } else {
+ size_t survived_guess = survived + promoted;
+ _avg_survived->sample(survived_guess);
+ }
+ avg_promoted()->sample(promoted + _avg_pretenured->padded_average());
+
+ if (PrintAdaptiveSizePolicy) {
+ gclog_or_tty->print(
+ "AdaptiveSizePolicy::compute_survivor_space_size_and_thresh:"
+ " survived: " SIZE_FORMAT
+ " promoted: " SIZE_FORMAT
+ " overflow: %s",
+ survived, promoted, is_survivor_overflow ? "true" : "false");
+ }
+}
+
+bool PSAdaptiveSizePolicy::print_adaptive_size_policy_on(outputStream* st)
+ const {
+
+ if (!UseAdaptiveSizePolicy) return false;
+
+ return AdaptiveSizePolicy::print_adaptive_size_policy_on(
+ st,
+ PSScavenge::tenuring_threshold());
+}