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1 /* |
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2 * Copyright (c) 2002, 2014, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 * |
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23 */ |
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24 |
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25 #include "precompiled.hpp" |
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26 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp" |
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27 #include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp" |
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28 #include "gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp" |
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29 #include "gc_implementation/parallelScavenge/psScavenge.hpp" |
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30 #include "gc_implementation/shared/gcPolicyCounters.hpp" |
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31 #include "gc_interface/gcCause.hpp" |
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32 #include "memory/collectorPolicy.hpp" |
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33 #include "runtime/timer.hpp" |
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34 #include "utilities/top.hpp" |
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35 |
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36 #include <math.h> |
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37 |
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38 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC |
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39 |
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40 PSAdaptiveSizePolicy::PSAdaptiveSizePolicy(size_t init_eden_size, |
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41 size_t init_promo_size, |
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42 size_t init_survivor_size, |
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43 size_t space_alignment, |
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44 double gc_pause_goal_sec, |
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45 double gc_minor_pause_goal_sec, |
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46 uint gc_cost_ratio) : |
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47 AdaptiveSizePolicy(init_eden_size, |
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48 init_promo_size, |
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49 init_survivor_size, |
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50 gc_pause_goal_sec, |
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51 gc_cost_ratio), |
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52 _collection_cost_margin_fraction(AdaptiveSizePolicyCollectionCostMargin / 100.0), |
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53 _space_alignment(space_alignment), |
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54 _live_at_last_full_gc(init_promo_size), |
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55 _gc_minor_pause_goal_sec(gc_minor_pause_goal_sec), |
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56 _latest_major_mutator_interval_seconds(0), |
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57 _young_gen_change_for_major_pause_count(0) |
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58 { |
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59 // Sizing policy statistics |
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60 _avg_major_pause = |
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61 new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding); |
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62 _avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); |
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63 _avg_major_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight); |
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64 |
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65 _avg_base_footprint = new AdaptiveWeightedAverage(AdaptiveSizePolicyWeight); |
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66 _major_pause_old_estimator = |
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67 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); |
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68 _major_pause_young_estimator = |
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69 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); |
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70 _major_collection_estimator = |
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71 new LinearLeastSquareFit(AdaptiveSizePolicyWeight); |
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72 |
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73 _young_gen_size_increment_supplement = YoungGenerationSizeSupplement; |
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74 _old_gen_size_increment_supplement = TenuredGenerationSizeSupplement; |
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75 |
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76 // Start the timers |
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77 _major_timer.start(); |
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78 |
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79 _old_gen_policy_is_ready = false; |
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80 } |
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81 |
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82 size_t PSAdaptiveSizePolicy::calculate_free_based_on_live(size_t live, uintx ratio_as_percentage) { |
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83 // We want to calculate how much free memory there can be based on the |
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84 // amount of live data currently in the old gen. Using the formula: |
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85 // ratio * (free + live) = free |
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86 // Some equation solving later we get: |
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87 // free = (live * ratio) / (1 - ratio) |
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88 |
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89 const double ratio = ratio_as_percentage / 100.0; |
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90 const double ratio_inverse = 1.0 - ratio; |
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91 const double tmp = live * ratio; |
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92 size_t free = (size_t)(tmp / ratio_inverse); |
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93 |
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94 return free; |
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95 } |
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96 |
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97 size_t PSAdaptiveSizePolicy::calculated_old_free_size_in_bytes() const { |
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98 size_t free_size = (size_t)(_promo_size + avg_promoted()->padded_average()); |
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99 size_t live = ParallelScavengeHeap::heap()->old_gen()->used_in_bytes(); |
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100 |
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101 if (MinHeapFreeRatio != 0) { |
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102 size_t min_free = calculate_free_based_on_live(live, MinHeapFreeRatio); |
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103 free_size = MAX2(free_size, min_free); |
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104 } |
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105 |
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106 if (MaxHeapFreeRatio != 100) { |
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107 size_t max_free = calculate_free_based_on_live(live, MaxHeapFreeRatio); |
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108 free_size = MIN2(max_free, free_size); |
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109 } |
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110 |
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111 return free_size; |
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112 } |
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113 |
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114 void PSAdaptiveSizePolicy::major_collection_begin() { |
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115 // Update the interval time |
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116 _major_timer.stop(); |
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117 // Save most recent collection time |
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118 _latest_major_mutator_interval_seconds = _major_timer.seconds(); |
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119 _major_timer.reset(); |
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120 _major_timer.start(); |
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121 } |
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122 |
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123 void PSAdaptiveSizePolicy::update_minor_pause_old_estimator( |
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124 double minor_pause_in_ms) { |
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125 double promo_size_in_mbytes = ((double)_promo_size)/((double)M); |
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126 _minor_pause_old_estimator->update(promo_size_in_mbytes, |
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127 minor_pause_in_ms); |
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128 } |
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129 |
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130 void PSAdaptiveSizePolicy::major_collection_end(size_t amount_live, |
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131 GCCause::Cause gc_cause) { |
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132 // Update the pause time. |
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133 _major_timer.stop(); |
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134 |
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135 if (gc_cause != GCCause::_java_lang_system_gc || |
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136 UseAdaptiveSizePolicyWithSystemGC) { |
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137 double major_pause_in_seconds = _major_timer.seconds(); |
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138 double major_pause_in_ms = major_pause_in_seconds * MILLIUNITS; |
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139 |
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140 // Sample for performance counter |
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141 _avg_major_pause->sample(major_pause_in_seconds); |
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142 |
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143 // Cost of collection (unit-less) |
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144 double collection_cost = 0.0; |
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145 if ((_latest_major_mutator_interval_seconds > 0.0) && |
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146 (major_pause_in_seconds > 0.0)) { |
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147 double interval_in_seconds = |
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148 _latest_major_mutator_interval_seconds + major_pause_in_seconds; |
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149 collection_cost = |
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150 major_pause_in_seconds / interval_in_seconds; |
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151 avg_major_gc_cost()->sample(collection_cost); |
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152 |
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153 // Sample for performance counter |
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154 _avg_major_interval->sample(interval_in_seconds); |
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155 } |
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156 |
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157 // Calculate variables used to estimate pause time vs. gen sizes |
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158 double eden_size_in_mbytes = ((double)_eden_size)/((double)M); |
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159 double promo_size_in_mbytes = ((double)_promo_size)/((double)M); |
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160 _major_pause_old_estimator->update(promo_size_in_mbytes, |
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161 major_pause_in_ms); |
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162 _major_pause_young_estimator->update(eden_size_in_mbytes, |
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163 major_pause_in_ms); |
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164 |
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165 if (PrintAdaptiveSizePolicy && Verbose) { |
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166 gclog_or_tty->print("psAdaptiveSizePolicy::major_collection_end: " |
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167 "major gc cost: %f average: %f", collection_cost, |
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168 avg_major_gc_cost()->average()); |
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169 gclog_or_tty->print_cr(" major pause: %f major period %f", |
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170 major_pause_in_ms, |
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171 _latest_major_mutator_interval_seconds * MILLIUNITS); |
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172 } |
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173 |
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174 // Calculate variable used to estimate collection cost vs. gen sizes |
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175 assert(collection_cost >= 0.0, "Expected to be non-negative"); |
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176 _major_collection_estimator->update(promo_size_in_mbytes, |
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177 collection_cost); |
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178 } |
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179 |
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180 // Update the amount live at the end of a full GC |
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181 _live_at_last_full_gc = amount_live; |
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182 |
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183 // The policy does not have enough data until at least some major collections |
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184 // have been done. |
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185 if (_avg_major_pause->count() >= AdaptiveSizePolicyReadyThreshold) { |
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186 _old_gen_policy_is_ready = true; |
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187 } |
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188 |
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189 // Interval times use this timer to measure the interval that |
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190 // the mutator runs. Reset after the GC pause has been measured. |
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191 _major_timer.reset(); |
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192 _major_timer.start(); |
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193 } |
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194 |
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195 // If the remaining free space in the old generation is less that |
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196 // that expected to be needed by the next collection, do a full |
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197 // collection now. |
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198 bool PSAdaptiveSizePolicy::should_full_GC(size_t old_free_in_bytes) { |
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199 |
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200 // A similar test is done in the scavenge's should_attempt_scavenge(). If |
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201 // this is changed, decide if that test should also be changed. |
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202 bool result = padded_average_promoted_in_bytes() > (float) old_free_in_bytes; |
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203 if (PrintGCDetails && Verbose) { |
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204 if (result) { |
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205 gclog_or_tty->print(" full after scavenge: "); |
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206 } else { |
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207 gclog_or_tty->print(" no full after scavenge: "); |
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208 } |
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209 gclog_or_tty->print_cr(" average_promoted " SIZE_FORMAT |
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210 " padded_average_promoted " SIZE_FORMAT |
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211 " free in old gen " SIZE_FORMAT, |
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212 (size_t) average_promoted_in_bytes(), |
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213 (size_t) padded_average_promoted_in_bytes(), |
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214 old_free_in_bytes); |
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215 } |
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216 return result; |
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217 } |
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218 |
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219 void PSAdaptiveSizePolicy::clear_generation_free_space_flags() { |
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220 |
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221 AdaptiveSizePolicy::clear_generation_free_space_flags(); |
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222 |
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223 set_change_old_gen_for_min_pauses(0); |
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224 |
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225 set_change_young_gen_for_maj_pauses(0); |
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226 } |
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227 |
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228 // If this is not a full GC, only test and modify the young generation. |
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229 |
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230 void PSAdaptiveSizePolicy::compute_generations_free_space( |
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231 size_t young_live, |
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232 size_t eden_live, |
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233 size_t old_live, |
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234 size_t cur_eden, |
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235 size_t max_old_gen_size, |
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236 size_t max_eden_size, |
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237 bool is_full_gc) { |
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238 compute_eden_space_size(young_live, |
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239 eden_live, |
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240 cur_eden, |
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241 max_eden_size, |
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242 is_full_gc); |
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243 |
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244 compute_old_gen_free_space(old_live, |
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245 cur_eden, |
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246 max_old_gen_size, |
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247 is_full_gc); |
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248 } |
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249 |
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250 void PSAdaptiveSizePolicy::compute_eden_space_size( |
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251 size_t young_live, |
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252 size_t eden_live, |
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253 size_t cur_eden, |
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254 size_t max_eden_size, |
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255 bool is_full_gc) { |
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256 |
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257 // Update statistics |
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258 // Time statistics are updated as we go, update footprint stats here |
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259 _avg_base_footprint->sample(BaseFootPrintEstimate); |
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260 avg_young_live()->sample(young_live); |
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261 avg_eden_live()->sample(eden_live); |
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262 |
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263 // This code used to return if the policy was not ready , i.e., |
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264 // policy_is_ready() returning false. The intent was that |
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265 // decisions below needed major collection times and so could |
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266 // not be made before two major collections. A consequence was |
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267 // adjustments to the young generation were not done until after |
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268 // two major collections even if the minor collections times |
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269 // exceeded the requested goals. Now let the young generation |
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270 // adjust for the minor collection times. Major collection times |
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271 // will be zero for the first collection and will naturally be |
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272 // ignored. Tenured generation adjustments are only made at the |
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273 // full collections so until the second major collection has |
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274 // been reached, no tenured generation adjustments will be made. |
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275 |
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276 // Until we know better, desired promotion size uses the last calculation |
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277 size_t desired_promo_size = _promo_size; |
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278 |
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279 // Start eden at the current value. The desired value that is stored |
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280 // in _eden_size is not bounded by constraints of the heap and can |
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281 // run away. |
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282 // |
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283 // As expected setting desired_eden_size to the current |
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284 // value of desired_eden_size as a starting point |
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285 // caused desired_eden_size to grow way too large and caused |
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286 // an overflow down stream. It may have improved performance in |
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287 // some case but is dangerous. |
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288 size_t desired_eden_size = cur_eden; |
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289 |
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290 // Cache some values. There's a bit of work getting these, so |
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291 // we might save a little time. |
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292 const double major_cost = major_gc_cost(); |
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293 const double minor_cost = minor_gc_cost(); |
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294 |
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295 // This method sets the desired eden size. That plus the |
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296 // desired survivor space sizes sets the desired young generation |
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297 // size. This methods does not know what the desired survivor |
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298 // size is but expects that other policy will attempt to make |
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299 // the survivor sizes compatible with the live data in the |
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300 // young generation. This limit is an estimate of the space left |
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301 // in the young generation after the survivor spaces have been |
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302 // subtracted out. |
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303 size_t eden_limit = max_eden_size; |
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304 |
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305 const double gc_cost_limit = GCTimeLimit/100.0; |
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306 |
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307 // Which way should we go? |
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308 // if pause requirement is not met |
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309 // adjust size of any generation with average paus exceeding |
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310 // the pause limit. Adjust one pause at a time (the larger) |
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311 // and only make adjustments for the major pause at full collections. |
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312 // else if throughput requirement not met |
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313 // adjust the size of the generation with larger gc time. Only |
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314 // adjust one generation at a time. |
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315 // else |
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316 // adjust down the total heap size. Adjust down the larger of the |
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317 // generations. |
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318 |
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319 // Add some checks for a threshold for a change. For example, |
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320 // a change less than the necessary alignment is probably not worth |
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321 // attempting. |
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322 |
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323 |
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324 if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) || |
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325 (_avg_major_pause->padded_average() > gc_pause_goal_sec())) { |
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326 // |
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327 // Check pauses |
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328 // |
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329 // Make changes only to affect one of the pauses (the larger) |
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330 // at a time. |
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331 adjust_eden_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size); |
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332 |
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333 } else if (_avg_minor_pause->padded_average() > gc_minor_pause_goal_sec()) { |
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334 // Adjust only for the minor pause time goal |
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335 adjust_eden_for_minor_pause_time(is_full_gc, &desired_eden_size); |
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336 |
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337 } else if(adjusted_mutator_cost() < _throughput_goal) { |
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338 // This branch used to require that (mutator_cost() > 0.0 in 1.4.2. |
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339 // This sometimes resulted in skipping to the minimize footprint |
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340 // code. Change this to try and reduce GC time if mutator time is |
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341 // negative for whatever reason. Or for future consideration, |
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342 // bail out of the code if mutator time is negative. |
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343 // |
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344 // Throughput |
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345 // |
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346 assert(major_cost >= 0.0, "major cost is < 0.0"); |
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347 assert(minor_cost >= 0.0, "minor cost is < 0.0"); |
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348 // Try to reduce the GC times. |
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349 adjust_eden_for_throughput(is_full_gc, &desired_eden_size); |
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350 |
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351 } else { |
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352 |
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353 // Be conservative about reducing the footprint. |
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354 // Do a minimum number of major collections first. |
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355 // Have reasonable averages for major and minor collections costs. |
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356 if (UseAdaptiveSizePolicyFootprintGoal && |
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357 young_gen_policy_is_ready() && |
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358 avg_major_gc_cost()->average() >= 0.0 && |
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359 avg_minor_gc_cost()->average() >= 0.0) { |
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360 size_t desired_sum = desired_eden_size + desired_promo_size; |
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361 desired_eden_size = adjust_eden_for_footprint(desired_eden_size, desired_sum); |
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362 } |
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363 } |
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364 |
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365 // Note we make the same tests as in the code block below; the code |
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366 // seems a little easier to read with the printing in another block. |
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367 if (PrintAdaptiveSizePolicy) { |
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368 if (desired_eden_size > eden_limit) { |
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369 gclog_or_tty->print_cr( |
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370 "PSAdaptiveSizePolicy::compute_eden_space_size limits:" |
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371 " desired_eden_size: " SIZE_FORMAT |
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372 " old_eden_size: " SIZE_FORMAT |
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373 " eden_limit: " SIZE_FORMAT |
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374 " cur_eden: " SIZE_FORMAT |
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375 " max_eden_size: " SIZE_FORMAT |
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376 " avg_young_live: " SIZE_FORMAT, |
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377 desired_eden_size, _eden_size, eden_limit, cur_eden, |
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378 max_eden_size, (size_t)avg_young_live()->average()); |
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379 } |
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380 if (gc_cost() > gc_cost_limit) { |
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381 gclog_or_tty->print_cr( |
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382 "PSAdaptiveSizePolicy::compute_eden_space_size: gc time limit" |
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383 " gc_cost: %f " |
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384 " GCTimeLimit: %d", |
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385 gc_cost(), GCTimeLimit); |
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386 } |
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387 } |
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388 |
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389 // Align everything and make a final limit check |
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390 desired_eden_size = align_size_up(desired_eden_size, _space_alignment); |
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391 desired_eden_size = MAX2(desired_eden_size, _space_alignment); |
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392 |
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393 eden_limit = align_size_down(eden_limit, _space_alignment); |
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394 |
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395 // And one last limit check, now that we've aligned things. |
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396 if (desired_eden_size > eden_limit) { |
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397 // If the policy says to get a larger eden but |
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398 // is hitting the limit, don't decrease eden. |
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399 // This can lead to a general drifting down of the |
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400 // eden size. Let the tenuring calculation push more |
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401 // into the old gen. |
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402 desired_eden_size = MAX2(eden_limit, cur_eden); |
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403 } |
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404 |
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405 if (PrintAdaptiveSizePolicy) { |
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406 // Timing stats |
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407 gclog_or_tty->print( |
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408 "PSAdaptiveSizePolicy::compute_eden_space_size: costs" |
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409 " minor_time: %f" |
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410 " major_cost: %f" |
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411 " mutator_cost: %f" |
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412 " throughput_goal: %f", |
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413 minor_gc_cost(), major_gc_cost(), mutator_cost(), |
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414 _throughput_goal); |
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415 |
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416 // We give more details if Verbose is set |
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417 if (Verbose) { |
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418 gclog_or_tty->print( " minor_pause: %f" |
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419 " major_pause: %f" |
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420 " minor_interval: %f" |
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421 " major_interval: %f" |
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422 " pause_goal: %f", |
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423 _avg_minor_pause->padded_average(), |
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424 _avg_major_pause->padded_average(), |
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425 _avg_minor_interval->average(), |
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426 _avg_major_interval->average(), |
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427 gc_pause_goal_sec()); |
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428 } |
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429 |
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430 // Footprint stats |
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431 gclog_or_tty->print( " live_space: " SIZE_FORMAT |
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432 " free_space: " SIZE_FORMAT, |
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433 live_space(), free_space()); |
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434 // More detail |
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435 if (Verbose) { |
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436 gclog_or_tty->print( " base_footprint: " SIZE_FORMAT |
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437 " avg_young_live: " SIZE_FORMAT |
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438 " avg_old_live: " SIZE_FORMAT, |
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439 (size_t)_avg_base_footprint->average(), |
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440 (size_t)avg_young_live()->average(), |
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441 (size_t)avg_old_live()->average()); |
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442 } |
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443 |
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444 // And finally, our old and new sizes. |
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445 gclog_or_tty->print(" old_eden_size: " SIZE_FORMAT |
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446 " desired_eden_size: " SIZE_FORMAT, |
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447 _eden_size, desired_eden_size); |
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448 gclog_or_tty->cr(); |
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449 } |
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450 |
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451 set_eden_size(desired_eden_size); |
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452 } |
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453 |
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454 void PSAdaptiveSizePolicy::compute_old_gen_free_space( |
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455 size_t old_live, |
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456 size_t cur_eden, |
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457 size_t max_old_gen_size, |
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458 bool is_full_gc) { |
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459 |
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460 // Update statistics |
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461 // Time statistics are updated as we go, update footprint stats here |
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462 if (is_full_gc) { |
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463 // old_live is only accurate after a full gc |
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464 avg_old_live()->sample(old_live); |
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465 } |
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466 |
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467 // This code used to return if the policy was not ready , i.e., |
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468 // policy_is_ready() returning false. The intent was that |
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469 // decisions below needed major collection times and so could |
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470 // not be made before two major collections. A consequence was |
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471 // adjustments to the young generation were not done until after |
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472 // two major collections even if the minor collections times |
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473 // exceeded the requested goals. Now let the young generation |
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474 // adjust for the minor collection times. Major collection times |
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475 // will be zero for the first collection and will naturally be |
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476 // ignored. Tenured generation adjustments are only made at the |
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477 // full collections so until the second major collection has |
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478 // been reached, no tenured generation adjustments will be made. |
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479 |
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480 // Until we know better, desired promotion size uses the last calculation |
|
481 size_t desired_promo_size = _promo_size; |
|
482 |
|
483 // Start eden at the current value. The desired value that is stored |
|
484 // in _eden_size is not bounded by constraints of the heap and can |
|
485 // run away. |
|
486 // |
|
487 // As expected setting desired_eden_size to the current |
|
488 // value of desired_eden_size as a starting point |
|
489 // caused desired_eden_size to grow way too large and caused |
|
490 // an overflow down stream. It may have improved performance in |
|
491 // some case but is dangerous. |
|
492 size_t desired_eden_size = cur_eden; |
|
493 |
|
494 // Cache some values. There's a bit of work getting these, so |
|
495 // we might save a little time. |
|
496 const double major_cost = major_gc_cost(); |
|
497 const double minor_cost = minor_gc_cost(); |
|
498 |
|
499 // Limits on our growth |
|
500 size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average()); |
|
501 |
|
502 // But don't force a promo size below the current promo size. Otherwise, |
|
503 // the promo size will shrink for no good reason. |
|
504 promo_limit = MAX2(promo_limit, _promo_size); |
|
505 |
|
506 const double gc_cost_limit = GCTimeLimit/100.0; |
|
507 |
|
508 // Which way should we go? |
|
509 // if pause requirement is not met |
|
510 // adjust size of any generation with average paus exceeding |
|
511 // the pause limit. Adjust one pause at a time (the larger) |
|
512 // and only make adjustments for the major pause at full collections. |
|
513 // else if throughput requirement not met |
|
514 // adjust the size of the generation with larger gc time. Only |
|
515 // adjust one generation at a time. |
|
516 // else |
|
517 // adjust down the total heap size. Adjust down the larger of the |
|
518 // generations. |
|
519 |
|
520 // Add some checks for a threshhold for a change. For example, |
|
521 // a change less than the necessary alignment is probably not worth |
|
522 // attempting. |
|
523 |
|
524 if ((_avg_minor_pause->padded_average() > gc_pause_goal_sec()) || |
|
525 (_avg_major_pause->padded_average() > gc_pause_goal_sec())) { |
|
526 // |
|
527 // Check pauses |
|
528 // |
|
529 // Make changes only to affect one of the pauses (the larger) |
|
530 // at a time. |
|
531 if (is_full_gc) { |
|
532 set_decide_at_full_gc(decide_at_full_gc_true); |
|
533 adjust_promo_for_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size); |
|
534 } |
|
535 } else if (_avg_minor_pause->padded_average() > gc_minor_pause_goal_sec()) { |
|
536 // Adjust only for the minor pause time goal |
|
537 adjust_promo_for_minor_pause_time(is_full_gc, &desired_promo_size, &desired_eden_size); |
|
538 } else if(adjusted_mutator_cost() < _throughput_goal) { |
|
539 // This branch used to require that (mutator_cost() > 0.0 in 1.4.2. |
|
540 // This sometimes resulted in skipping to the minimize footprint |
|
541 // code. Change this to try and reduce GC time if mutator time is |
|
542 // negative for whatever reason. Or for future consideration, |
|
543 // bail out of the code if mutator time is negative. |
|
544 // |
|
545 // Throughput |
|
546 // |
|
547 assert(major_cost >= 0.0, "major cost is < 0.0"); |
|
548 assert(minor_cost >= 0.0, "minor cost is < 0.0"); |
|
549 // Try to reduce the GC times. |
|
550 if (is_full_gc) { |
|
551 set_decide_at_full_gc(decide_at_full_gc_true); |
|
552 adjust_promo_for_throughput(is_full_gc, &desired_promo_size); |
|
553 } |
|
554 } else { |
|
555 |
|
556 // Be conservative about reducing the footprint. |
|
557 // Do a minimum number of major collections first. |
|
558 // Have reasonable averages for major and minor collections costs. |
|
559 if (UseAdaptiveSizePolicyFootprintGoal && |
|
560 young_gen_policy_is_ready() && |
|
561 avg_major_gc_cost()->average() >= 0.0 && |
|
562 avg_minor_gc_cost()->average() >= 0.0) { |
|
563 if (is_full_gc) { |
|
564 set_decide_at_full_gc(decide_at_full_gc_true); |
|
565 size_t desired_sum = desired_eden_size + desired_promo_size; |
|
566 desired_promo_size = adjust_promo_for_footprint(desired_promo_size, desired_sum); |
|
567 } |
|
568 } |
|
569 } |
|
570 |
|
571 // Note we make the same tests as in the code block below; the code |
|
572 // seems a little easier to read with the printing in another block. |
|
573 if (PrintAdaptiveSizePolicy) { |
|
574 if (desired_promo_size > promo_limit) { |
|
575 // "free_in_old_gen" was the original value for used for promo_limit |
|
576 size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average()); |
|
577 gclog_or_tty->print_cr( |
|
578 "PSAdaptiveSizePolicy::compute_old_gen_free_space limits:" |
|
579 " desired_promo_size: " SIZE_FORMAT |
|
580 " promo_limit: " SIZE_FORMAT |
|
581 " free_in_old_gen: " SIZE_FORMAT |
|
582 " max_old_gen_size: " SIZE_FORMAT |
|
583 " avg_old_live: " SIZE_FORMAT, |
|
584 desired_promo_size, promo_limit, free_in_old_gen, |
|
585 max_old_gen_size, (size_t) avg_old_live()->average()); |
|
586 } |
|
587 if (gc_cost() > gc_cost_limit) { |
|
588 gclog_or_tty->print_cr( |
|
589 "PSAdaptiveSizePolicy::compute_old_gen_free_space: gc time limit" |
|
590 " gc_cost: %f " |
|
591 " GCTimeLimit: %d", |
|
592 gc_cost(), GCTimeLimit); |
|
593 } |
|
594 } |
|
595 |
|
596 // Align everything and make a final limit check |
|
597 desired_promo_size = align_size_up(desired_promo_size, _space_alignment); |
|
598 desired_promo_size = MAX2(desired_promo_size, _space_alignment); |
|
599 |
|
600 promo_limit = align_size_down(promo_limit, _space_alignment); |
|
601 |
|
602 // And one last limit check, now that we've aligned things. |
|
603 desired_promo_size = MIN2(desired_promo_size, promo_limit); |
|
604 |
|
605 if (PrintAdaptiveSizePolicy) { |
|
606 // Timing stats |
|
607 gclog_or_tty->print( |
|
608 "PSAdaptiveSizePolicy::compute_old_gen_free_space: costs" |
|
609 " minor_time: %f" |
|
610 " major_cost: %f" |
|
611 " mutator_cost: %f" |
|
612 " throughput_goal: %f", |
|
613 minor_gc_cost(), major_gc_cost(), mutator_cost(), |
|
614 _throughput_goal); |
|
615 |
|
616 // We give more details if Verbose is set |
|
617 if (Verbose) { |
|
618 gclog_or_tty->print( " minor_pause: %f" |
|
619 " major_pause: %f" |
|
620 " minor_interval: %f" |
|
621 " major_interval: %f" |
|
622 " pause_goal: %f", |
|
623 _avg_minor_pause->padded_average(), |
|
624 _avg_major_pause->padded_average(), |
|
625 _avg_minor_interval->average(), |
|
626 _avg_major_interval->average(), |
|
627 gc_pause_goal_sec()); |
|
628 } |
|
629 |
|
630 // Footprint stats |
|
631 gclog_or_tty->print( " live_space: " SIZE_FORMAT |
|
632 " free_space: " SIZE_FORMAT, |
|
633 live_space(), free_space()); |
|
634 // More detail |
|
635 if (Verbose) { |
|
636 gclog_or_tty->print( " base_footprint: " SIZE_FORMAT |
|
637 " avg_young_live: " SIZE_FORMAT |
|
638 " avg_old_live: " SIZE_FORMAT, |
|
639 (size_t)_avg_base_footprint->average(), |
|
640 (size_t)avg_young_live()->average(), |
|
641 (size_t)avg_old_live()->average()); |
|
642 } |
|
643 |
|
644 // And finally, our old and new sizes. |
|
645 gclog_or_tty->print(" old_promo_size: " SIZE_FORMAT |
|
646 " desired_promo_size: " SIZE_FORMAT, |
|
647 _promo_size, desired_promo_size); |
|
648 gclog_or_tty->cr(); |
|
649 } |
|
650 |
|
651 set_promo_size(desired_promo_size); |
|
652 } |
|
653 |
|
654 void PSAdaptiveSizePolicy::decay_supplemental_growth(bool is_full_gc) { |
|
655 // Decay the supplemental increment? Decay the supplement growth |
|
656 // factor even if it is not used. It is only meant to give a boost |
|
657 // to the initial growth and if it is not used, then it was not |
|
658 // needed. |
|
659 if (is_full_gc) { |
|
660 // Don't wait for the threshold value for the major collections. If |
|
661 // here, the supplemental growth term was used and should decay. |
|
662 if ((_avg_major_pause->count() % TenuredGenerationSizeSupplementDecay) |
|
663 == 0) { |
|
664 _old_gen_size_increment_supplement = |
|
665 _old_gen_size_increment_supplement >> 1; |
|
666 } |
|
667 } else { |
|
668 if ((_avg_minor_pause->count() >= AdaptiveSizePolicyReadyThreshold) && |
|
669 (_avg_minor_pause->count() % YoungGenerationSizeSupplementDecay) == 0) { |
|
670 _young_gen_size_increment_supplement = |
|
671 _young_gen_size_increment_supplement >> 1; |
|
672 } |
|
673 } |
|
674 } |
|
675 |
|
676 void PSAdaptiveSizePolicy::adjust_promo_for_minor_pause_time(bool is_full_gc, |
|
677 size_t* desired_promo_size_ptr, size_t* desired_eden_size_ptr) { |
|
678 |
|
679 if (PSAdjustTenuredGenForMinorPause) { |
|
680 if (is_full_gc) { |
|
681 set_decide_at_full_gc(decide_at_full_gc_true); |
|
682 } |
|
683 // If the desired eden size is as small as it will get, |
|
684 // try to adjust the old gen size. |
|
685 if (*desired_eden_size_ptr <= _space_alignment) { |
|
686 // Vary the old gen size to reduce the young gen pause. This |
|
687 // may not be a good idea. This is just a test. |
|
688 if (minor_pause_old_estimator()->decrement_will_decrease()) { |
|
689 set_change_old_gen_for_min_pauses(decrease_old_gen_for_min_pauses_true); |
|
690 *desired_promo_size_ptr = |
|
691 _promo_size - promo_decrement_aligned_down(*desired_promo_size_ptr); |
|
692 } else { |
|
693 set_change_old_gen_for_min_pauses(increase_old_gen_for_min_pauses_true); |
|
694 size_t promo_heap_delta = |
|
695 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr); |
|
696 if ((*desired_promo_size_ptr + promo_heap_delta) > |
|
697 *desired_promo_size_ptr) { |
|
698 *desired_promo_size_ptr = |
|
699 _promo_size + promo_heap_delta; |
|
700 } |
|
701 } |
|
702 } |
|
703 } |
|
704 } |
|
705 |
|
706 void PSAdaptiveSizePolicy::adjust_eden_for_minor_pause_time(bool is_full_gc, |
|
707 size_t* desired_eden_size_ptr) { |
|
708 |
|
709 // Adjust the young generation size to reduce pause time of |
|
710 // of collections. |
|
711 // |
|
712 // The AdaptiveSizePolicyInitializingSteps test is not used |
|
713 // here. It has not seemed to be needed but perhaps should |
|
714 // be added for consistency. |
|
715 if (minor_pause_young_estimator()->decrement_will_decrease()) { |
|
716 // reduce eden size |
|
717 set_change_young_gen_for_min_pauses( |
|
718 decrease_young_gen_for_min_pauses_true); |
|
719 *desired_eden_size_ptr = *desired_eden_size_ptr - |
|
720 eden_decrement_aligned_down(*desired_eden_size_ptr); |
|
721 } else { |
|
722 // EXPERIMENTAL ADJUSTMENT |
|
723 // Only record that the estimator indicated such an action. |
|
724 // *desired_eden_size_ptr = *desired_eden_size_ptr + eden_heap_delta; |
|
725 set_change_young_gen_for_min_pauses( |
|
726 increase_young_gen_for_min_pauses_true); |
|
727 } |
|
728 } |
|
729 |
|
730 void PSAdaptiveSizePolicy::adjust_promo_for_pause_time(bool is_full_gc, |
|
731 size_t* desired_promo_size_ptr, |
|
732 size_t* desired_eden_size_ptr) { |
|
733 |
|
734 size_t promo_heap_delta = 0; |
|
735 // Add some checks for a threshold for a change. For example, |
|
736 // a change less than the required alignment is probably not worth |
|
737 // attempting. |
|
738 |
|
739 if (_avg_minor_pause->padded_average() > _avg_major_pause->padded_average()) { |
|
740 adjust_promo_for_minor_pause_time(is_full_gc, desired_promo_size_ptr, desired_eden_size_ptr); |
|
741 // major pause adjustments |
|
742 } else if (is_full_gc) { |
|
743 // Adjust for the major pause time only at full gc's because the |
|
744 // affects of a change can only be seen at full gc's. |
|
745 |
|
746 // Reduce old generation size to reduce pause? |
|
747 if (major_pause_old_estimator()->decrement_will_decrease()) { |
|
748 // reduce old generation size |
|
749 set_change_old_gen_for_maj_pauses(decrease_old_gen_for_maj_pauses_true); |
|
750 promo_heap_delta = promo_decrement_aligned_down(*desired_promo_size_ptr); |
|
751 *desired_promo_size_ptr = _promo_size - promo_heap_delta; |
|
752 } else { |
|
753 // EXPERIMENTAL ADJUSTMENT |
|
754 // Only record that the estimator indicated such an action. |
|
755 // *desired_promo_size_ptr = _promo_size + |
|
756 // promo_increment_aligned_up(*desired_promo_size_ptr); |
|
757 set_change_old_gen_for_maj_pauses(increase_old_gen_for_maj_pauses_true); |
|
758 } |
|
759 } |
|
760 |
|
761 if (PrintAdaptiveSizePolicy && Verbose) { |
|
762 gclog_or_tty->print_cr( |
|
763 "PSAdaptiveSizePolicy::adjust_promo_for_pause_time " |
|
764 "adjusting gen sizes for major pause (avg %f goal %f). " |
|
765 "desired_promo_size " SIZE_FORMAT " promo delta " SIZE_FORMAT, |
|
766 _avg_major_pause->average(), gc_pause_goal_sec(), |
|
767 *desired_promo_size_ptr, promo_heap_delta); |
|
768 } |
|
769 } |
|
770 |
|
771 void PSAdaptiveSizePolicy::adjust_eden_for_pause_time(bool is_full_gc, |
|
772 size_t* desired_promo_size_ptr, |
|
773 size_t* desired_eden_size_ptr) { |
|
774 |
|
775 size_t eden_heap_delta = 0; |
|
776 // Add some checks for a threshold for a change. For example, |
|
777 // a change less than the required alignment is probably not worth |
|
778 // attempting. |
|
779 if (_avg_minor_pause->padded_average() > _avg_major_pause->padded_average()) { |
|
780 adjust_eden_for_minor_pause_time(is_full_gc, |
|
781 desired_eden_size_ptr); |
|
782 // major pause adjustments |
|
783 } else if (is_full_gc) { |
|
784 // Adjust for the major pause time only at full gc's because the |
|
785 // affects of a change can only be seen at full gc's. |
|
786 if (PSAdjustYoungGenForMajorPause) { |
|
787 // If the promo size is at the minimum (i.e., the old gen |
|
788 // size will not actually decrease), consider changing the |
|
789 // young gen size. |
|
790 if (*desired_promo_size_ptr < _space_alignment) { |
|
791 // If increasing the young generation will decrease the old gen |
|
792 // pause, do it. |
|
793 // During startup there is noise in the statistics for deciding |
|
794 // on whether to increase or decrease the young gen size. For |
|
795 // some number of iterations, just try to increase the young |
|
796 // gen size if the major pause is too long to try and establish |
|
797 // good statistics for later decisions. |
|
798 if (major_pause_young_estimator()->increment_will_decrease() || |
|
799 (_young_gen_change_for_major_pause_count |
|
800 <= AdaptiveSizePolicyInitializingSteps)) { |
|
801 set_change_young_gen_for_maj_pauses( |
|
802 increase_young_gen_for_maj_pauses_true); |
|
803 eden_heap_delta = eden_increment_aligned_up(*desired_eden_size_ptr); |
|
804 *desired_eden_size_ptr = _eden_size + eden_heap_delta; |
|
805 _young_gen_change_for_major_pause_count++; |
|
806 } else { |
|
807 // Record that decreasing the young gen size would decrease |
|
808 // the major pause |
|
809 set_change_young_gen_for_maj_pauses( |
|
810 decrease_young_gen_for_maj_pauses_true); |
|
811 eden_heap_delta = eden_decrement_aligned_down(*desired_eden_size_ptr); |
|
812 *desired_eden_size_ptr = _eden_size - eden_heap_delta; |
|
813 } |
|
814 } |
|
815 } |
|
816 } |
|
817 |
|
818 if (PrintAdaptiveSizePolicy && Verbose) { |
|
819 gclog_or_tty->print_cr( |
|
820 "PSAdaptiveSizePolicy::adjust_eden_for_pause_time " |
|
821 "adjusting gen sizes for major pause (avg %f goal %f). " |
|
822 "desired_eden_size " SIZE_FORMAT " eden delta " SIZE_FORMAT, |
|
823 _avg_major_pause->average(), gc_pause_goal_sec(), |
|
824 *desired_eden_size_ptr, eden_heap_delta); |
|
825 } |
|
826 } |
|
827 |
|
828 void PSAdaptiveSizePolicy::adjust_promo_for_throughput(bool is_full_gc, |
|
829 size_t* desired_promo_size_ptr) { |
|
830 |
|
831 // Add some checks for a threshold for a change. For example, |
|
832 // a change less than the required alignment is probably not worth |
|
833 // attempting. |
|
834 |
|
835 if ((gc_cost() + mutator_cost()) == 0.0) { |
|
836 return; |
|
837 } |
|
838 |
|
839 if (PrintAdaptiveSizePolicy && Verbose) { |
|
840 gclog_or_tty->print("\nPSAdaptiveSizePolicy::adjust_promo_for_throughput(" |
|
841 "is_full: %d, promo: " SIZE_FORMAT "): ", |
|
842 is_full_gc, *desired_promo_size_ptr); |
|
843 gclog_or_tty->print_cr("mutator_cost %f major_gc_cost %f " |
|
844 "minor_gc_cost %f", mutator_cost(), major_gc_cost(), minor_gc_cost()); |
|
845 } |
|
846 |
|
847 // Tenured generation |
|
848 if (is_full_gc) { |
|
849 // Calculate the change to use for the tenured gen. |
|
850 size_t scaled_promo_heap_delta = 0; |
|
851 // Can the increment to the generation be scaled? |
|
852 if (gc_cost() >= 0.0 && major_gc_cost() >= 0.0) { |
|
853 size_t promo_heap_delta = |
|
854 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr); |
|
855 double scale_by_ratio = major_gc_cost() / gc_cost(); |
|
856 scaled_promo_heap_delta = |
|
857 (size_t) (scale_by_ratio * (double) promo_heap_delta); |
|
858 if (PrintAdaptiveSizePolicy && Verbose) { |
|
859 gclog_or_tty->print_cr( |
|
860 "Scaled tenured increment: " SIZE_FORMAT " by %f down to " |
|
861 SIZE_FORMAT, |
|
862 promo_heap_delta, scale_by_ratio, scaled_promo_heap_delta); |
|
863 } |
|
864 } else if (major_gc_cost() >= 0.0) { |
|
865 // Scaling is not going to work. If the major gc time is the |
|
866 // larger, give it a full increment. |
|
867 if (major_gc_cost() >= minor_gc_cost()) { |
|
868 scaled_promo_heap_delta = |
|
869 promo_increment_with_supplement_aligned_up(*desired_promo_size_ptr); |
|
870 } |
|
871 } else { |
|
872 // Don't expect to get here but it's ok if it does |
|
873 // in the product build since the delta will be 0 |
|
874 // and nothing will change. |
|
875 assert(false, "Unexpected value for gc costs"); |
|
876 } |
|
877 |
|
878 switch (AdaptiveSizeThroughPutPolicy) { |
|
879 case 1: |
|
880 // Early in the run the statistics might not be good. Until |
|
881 // a specific number of collections have been, use the heuristic |
|
882 // that a larger generation size means lower collection costs. |
|
883 if (major_collection_estimator()->increment_will_decrease() || |
|
884 (_old_gen_change_for_major_throughput |
|
885 <= AdaptiveSizePolicyInitializingSteps)) { |
|
886 // Increase tenured generation size to reduce major collection cost |
|
887 if ((*desired_promo_size_ptr + scaled_promo_heap_delta) > |
|
888 *desired_promo_size_ptr) { |
|
889 *desired_promo_size_ptr = _promo_size + scaled_promo_heap_delta; |
|
890 } |
|
891 set_change_old_gen_for_throughput( |
|
892 increase_old_gen_for_throughput_true); |
|
893 _old_gen_change_for_major_throughput++; |
|
894 } else { |
|
895 // EXPERIMENTAL ADJUSTMENT |
|
896 // Record that decreasing the old gen size would decrease |
|
897 // the major collection cost but don't do it. |
|
898 // *desired_promo_size_ptr = _promo_size - |
|
899 // promo_decrement_aligned_down(*desired_promo_size_ptr); |
|
900 set_change_old_gen_for_throughput( |
|
901 decrease_old_gen_for_throughput_true); |
|
902 } |
|
903 |
|
904 break; |
|
905 default: |
|
906 // Simplest strategy |
|
907 if ((*desired_promo_size_ptr + scaled_promo_heap_delta) > |
|
908 *desired_promo_size_ptr) { |
|
909 *desired_promo_size_ptr = *desired_promo_size_ptr + |
|
910 scaled_promo_heap_delta; |
|
911 } |
|
912 set_change_old_gen_for_throughput( |
|
913 increase_old_gen_for_throughput_true); |
|
914 _old_gen_change_for_major_throughput++; |
|
915 } |
|
916 |
|
917 if (PrintAdaptiveSizePolicy && Verbose) { |
|
918 gclog_or_tty->print_cr( |
|
919 "adjusting tenured gen for throughput (avg %f goal %f). " |
|
920 "desired_promo_size " SIZE_FORMAT " promo_delta " SIZE_FORMAT , |
|
921 mutator_cost(), _throughput_goal, |
|
922 *desired_promo_size_ptr, scaled_promo_heap_delta); |
|
923 } |
|
924 } |
|
925 } |
|
926 |
|
927 void PSAdaptiveSizePolicy::adjust_eden_for_throughput(bool is_full_gc, |
|
928 size_t* desired_eden_size_ptr) { |
|
929 |
|
930 // Add some checks for a threshold for a change. For example, |
|
931 // a change less than the required alignment is probably not worth |
|
932 // attempting. |
|
933 |
|
934 if ((gc_cost() + mutator_cost()) == 0.0) { |
|
935 return; |
|
936 } |
|
937 |
|
938 if (PrintAdaptiveSizePolicy && Verbose) { |
|
939 gclog_or_tty->print("\nPSAdaptiveSizePolicy::adjust_eden_for_throughput(" |
|
940 "is_full: %d, cur_eden: " SIZE_FORMAT "): ", |
|
941 is_full_gc, *desired_eden_size_ptr); |
|
942 gclog_or_tty->print_cr("mutator_cost %f major_gc_cost %f " |
|
943 "minor_gc_cost %f", mutator_cost(), major_gc_cost(), minor_gc_cost()); |
|
944 } |
|
945 |
|
946 // Young generation |
|
947 size_t scaled_eden_heap_delta = 0; |
|
948 // Can the increment to the generation be scaled? |
|
949 if (gc_cost() >= 0.0 && minor_gc_cost() >= 0.0) { |
|
950 size_t eden_heap_delta = |
|
951 eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr); |
|
952 double scale_by_ratio = minor_gc_cost() / gc_cost(); |
|
953 assert(scale_by_ratio <= 1.0 && scale_by_ratio >= 0.0, "Scaling is wrong"); |
|
954 scaled_eden_heap_delta = |
|
955 (size_t) (scale_by_ratio * (double) eden_heap_delta); |
|
956 if (PrintAdaptiveSizePolicy && Verbose) { |
|
957 gclog_or_tty->print_cr( |
|
958 "Scaled eden increment: " SIZE_FORMAT " by %f down to " |
|
959 SIZE_FORMAT, |
|
960 eden_heap_delta, scale_by_ratio, scaled_eden_heap_delta); |
|
961 } |
|
962 } else if (minor_gc_cost() >= 0.0) { |
|
963 // Scaling is not going to work. If the minor gc time is the |
|
964 // larger, give it a full increment. |
|
965 if (minor_gc_cost() > major_gc_cost()) { |
|
966 scaled_eden_heap_delta = |
|
967 eden_increment_with_supplement_aligned_up(*desired_eden_size_ptr); |
|
968 } |
|
969 } else { |
|
970 // Don't expect to get here but it's ok if it does |
|
971 // in the product build since the delta will be 0 |
|
972 // and nothing will change. |
|
973 assert(false, "Unexpected value for gc costs"); |
|
974 } |
|
975 |
|
976 // Use a heuristic for some number of collections to give |
|
977 // the averages time to settle down. |
|
978 switch (AdaptiveSizeThroughPutPolicy) { |
|
979 case 1: |
|
980 if (minor_collection_estimator()->increment_will_decrease() || |
|
981 (_young_gen_change_for_minor_throughput |
|
982 <= AdaptiveSizePolicyInitializingSteps)) { |
|
983 // Expand young generation size to reduce frequency of |
|
984 // of collections. |
|
985 if ((*desired_eden_size_ptr + scaled_eden_heap_delta) > |
|
986 *desired_eden_size_ptr) { |
|
987 *desired_eden_size_ptr = |
|
988 *desired_eden_size_ptr + scaled_eden_heap_delta; |
|
989 } |
|
990 set_change_young_gen_for_throughput( |
|
991 increase_young_gen_for_througput_true); |
|
992 _young_gen_change_for_minor_throughput++; |
|
993 } else { |
|
994 // EXPERIMENTAL ADJUSTMENT |
|
995 // Record that decreasing the young gen size would decrease |
|
996 // the minor collection cost but don't do it. |
|
997 // *desired_eden_size_ptr = _eden_size - |
|
998 // eden_decrement_aligned_down(*desired_eden_size_ptr); |
|
999 set_change_young_gen_for_throughput( |
|
1000 decrease_young_gen_for_througput_true); |
|
1001 } |
|
1002 break; |
|
1003 default: |
|
1004 if ((*desired_eden_size_ptr + scaled_eden_heap_delta) > |
|
1005 *desired_eden_size_ptr) { |
|
1006 *desired_eden_size_ptr = |
|
1007 *desired_eden_size_ptr + scaled_eden_heap_delta; |
|
1008 } |
|
1009 set_change_young_gen_for_throughput( |
|
1010 increase_young_gen_for_througput_true); |
|
1011 _young_gen_change_for_minor_throughput++; |
|
1012 } |
|
1013 |
|
1014 if (PrintAdaptiveSizePolicy && Verbose) { |
|
1015 gclog_or_tty->print_cr( |
|
1016 "adjusting eden for throughput (avg %f goal %f). desired_eden_size " |
|
1017 SIZE_FORMAT " eden delta " SIZE_FORMAT "\n", |
|
1018 mutator_cost(), _throughput_goal, |
|
1019 *desired_eden_size_ptr, scaled_eden_heap_delta); |
|
1020 } |
|
1021 } |
|
1022 |
|
1023 size_t PSAdaptiveSizePolicy::adjust_promo_for_footprint( |
|
1024 size_t desired_promo_size, size_t desired_sum) { |
|
1025 assert(desired_promo_size <= desired_sum, "Inconsistent parameters"); |
|
1026 set_decrease_for_footprint(decrease_old_gen_for_footprint_true); |
|
1027 |
|
1028 size_t change = promo_decrement(desired_promo_size); |
|
1029 change = scale_down(change, desired_promo_size, desired_sum); |
|
1030 |
|
1031 size_t reduced_size = desired_promo_size - change; |
|
1032 |
|
1033 if (PrintAdaptiveSizePolicy && Verbose) { |
|
1034 gclog_or_tty->print_cr( |
|
1035 "AdaptiveSizePolicy::adjust_promo_for_footprint " |
|
1036 "adjusting tenured gen for footprint. " |
|
1037 "starting promo size " SIZE_FORMAT |
|
1038 " reduced promo size " SIZE_FORMAT |
|
1039 " promo delta " SIZE_FORMAT, |
|
1040 desired_promo_size, reduced_size, change ); |
|
1041 } |
|
1042 |
|
1043 assert(reduced_size <= desired_promo_size, "Inconsistent result"); |
|
1044 return reduced_size; |
|
1045 } |
|
1046 |
|
1047 size_t PSAdaptiveSizePolicy::adjust_eden_for_footprint( |
|
1048 size_t desired_eden_size, size_t desired_sum) { |
|
1049 assert(desired_eden_size <= desired_sum, "Inconsistent parameters"); |
|
1050 set_decrease_for_footprint(decrease_young_gen_for_footprint_true); |
|
1051 |
|
1052 size_t change = eden_decrement(desired_eden_size); |
|
1053 change = scale_down(change, desired_eden_size, desired_sum); |
|
1054 |
|
1055 size_t reduced_size = desired_eden_size - change; |
|
1056 |
|
1057 if (PrintAdaptiveSizePolicy && Verbose) { |
|
1058 gclog_or_tty->print_cr( |
|
1059 "AdaptiveSizePolicy::adjust_eden_for_footprint " |
|
1060 "adjusting eden for footprint. " |
|
1061 " starting eden size " SIZE_FORMAT |
|
1062 " reduced eden size " SIZE_FORMAT |
|
1063 " eden delta " SIZE_FORMAT, |
|
1064 desired_eden_size, reduced_size, change); |
|
1065 } |
|
1066 |
|
1067 assert(reduced_size <= desired_eden_size, "Inconsistent result"); |
|
1068 return reduced_size; |
|
1069 } |
|
1070 |
|
1071 // Scale down "change" by the factor |
|
1072 // part / total |
|
1073 // Don't align the results. |
|
1074 |
|
1075 size_t PSAdaptiveSizePolicy::scale_down(size_t change, |
|
1076 double part, |
|
1077 double total) { |
|
1078 assert(part <= total, "Inconsistent input"); |
|
1079 size_t reduced_change = change; |
|
1080 if (total > 0) { |
|
1081 double fraction = part / total; |
|
1082 reduced_change = (size_t) (fraction * (double) change); |
|
1083 } |
|
1084 assert(reduced_change <= change, "Inconsistent result"); |
|
1085 return reduced_change; |
|
1086 } |
|
1087 |
|
1088 size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden, |
|
1089 uint percent_change) { |
|
1090 size_t eden_heap_delta; |
|
1091 eden_heap_delta = cur_eden / 100 * percent_change; |
|
1092 return eden_heap_delta; |
|
1093 } |
|
1094 |
|
1095 size_t PSAdaptiveSizePolicy::eden_increment(size_t cur_eden) { |
|
1096 return eden_increment(cur_eden, YoungGenerationSizeIncrement); |
|
1097 } |
|
1098 |
|
1099 size_t PSAdaptiveSizePolicy::eden_increment_aligned_up(size_t cur_eden) { |
|
1100 size_t result = eden_increment(cur_eden, YoungGenerationSizeIncrement); |
|
1101 return align_size_up(result, _space_alignment); |
|
1102 } |
|
1103 |
|
1104 size_t PSAdaptiveSizePolicy::eden_increment_aligned_down(size_t cur_eden) { |
|
1105 size_t result = eden_increment(cur_eden); |
|
1106 return align_size_down(result, _space_alignment); |
|
1107 } |
|
1108 |
|
1109 size_t PSAdaptiveSizePolicy::eden_increment_with_supplement_aligned_up( |
|
1110 size_t cur_eden) { |
|
1111 size_t result = eden_increment(cur_eden, |
|
1112 YoungGenerationSizeIncrement + _young_gen_size_increment_supplement); |
|
1113 return align_size_up(result, _space_alignment); |
|
1114 } |
|
1115 |
|
1116 size_t PSAdaptiveSizePolicy::eden_decrement_aligned_down(size_t cur_eden) { |
|
1117 size_t eden_heap_delta = eden_decrement(cur_eden); |
|
1118 return align_size_down(eden_heap_delta, _space_alignment); |
|
1119 } |
|
1120 |
|
1121 size_t PSAdaptiveSizePolicy::eden_decrement(size_t cur_eden) { |
|
1122 size_t eden_heap_delta = eden_increment(cur_eden) / |
|
1123 AdaptiveSizeDecrementScaleFactor; |
|
1124 return eden_heap_delta; |
|
1125 } |
|
1126 |
|
1127 size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo, |
|
1128 uint percent_change) { |
|
1129 size_t promo_heap_delta; |
|
1130 promo_heap_delta = cur_promo / 100 * percent_change; |
|
1131 return promo_heap_delta; |
|
1132 } |
|
1133 |
|
1134 size_t PSAdaptiveSizePolicy::promo_increment(size_t cur_promo) { |
|
1135 return promo_increment(cur_promo, TenuredGenerationSizeIncrement); |
|
1136 } |
|
1137 |
|
1138 size_t PSAdaptiveSizePolicy::promo_increment_aligned_up(size_t cur_promo) { |
|
1139 size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement); |
|
1140 return align_size_up(result, _space_alignment); |
|
1141 } |
|
1142 |
|
1143 size_t PSAdaptiveSizePolicy::promo_increment_aligned_down(size_t cur_promo) { |
|
1144 size_t result = promo_increment(cur_promo, TenuredGenerationSizeIncrement); |
|
1145 return align_size_down(result, _space_alignment); |
|
1146 } |
|
1147 |
|
1148 size_t PSAdaptiveSizePolicy::promo_increment_with_supplement_aligned_up( |
|
1149 size_t cur_promo) { |
|
1150 size_t result = promo_increment(cur_promo, |
|
1151 TenuredGenerationSizeIncrement + _old_gen_size_increment_supplement); |
|
1152 return align_size_up(result, _space_alignment); |
|
1153 } |
|
1154 |
|
1155 size_t PSAdaptiveSizePolicy::promo_decrement_aligned_down(size_t cur_promo) { |
|
1156 size_t promo_heap_delta = promo_decrement(cur_promo); |
|
1157 return align_size_down(promo_heap_delta, _space_alignment); |
|
1158 } |
|
1159 |
|
1160 size_t PSAdaptiveSizePolicy::promo_decrement(size_t cur_promo) { |
|
1161 size_t promo_heap_delta = promo_increment(cur_promo); |
|
1162 promo_heap_delta = promo_heap_delta / AdaptiveSizeDecrementScaleFactor; |
|
1163 return promo_heap_delta; |
|
1164 } |
|
1165 |
|
1166 uint PSAdaptiveSizePolicy::compute_survivor_space_size_and_threshold( |
|
1167 bool is_survivor_overflow, |
|
1168 uint tenuring_threshold, |
|
1169 size_t survivor_limit) { |
|
1170 assert(survivor_limit >= _space_alignment, |
|
1171 "survivor_limit too small"); |
|
1172 assert((size_t)align_size_down(survivor_limit, _space_alignment) |
|
1173 == survivor_limit, "survivor_limit not aligned"); |
|
1174 |
|
1175 // This method is called even if the tenuring threshold and survivor |
|
1176 // spaces are not adjusted so that the averages are sampled above. |
|
1177 if (!UsePSAdaptiveSurvivorSizePolicy || |
|
1178 !young_gen_policy_is_ready()) { |
|
1179 return tenuring_threshold; |
|
1180 } |
|
1181 |
|
1182 // We'll decide whether to increase or decrease the tenuring |
|
1183 // threshold based partly on the newly computed survivor size |
|
1184 // (if we hit the maximum limit allowed, we'll always choose to |
|
1185 // decrement the threshold). |
|
1186 bool incr_tenuring_threshold = false; |
|
1187 bool decr_tenuring_threshold = false; |
|
1188 |
|
1189 set_decrement_tenuring_threshold_for_gc_cost(false); |
|
1190 set_increment_tenuring_threshold_for_gc_cost(false); |
|
1191 set_decrement_tenuring_threshold_for_survivor_limit(false); |
|
1192 |
|
1193 if (!is_survivor_overflow) { |
|
1194 // Keep running averages on how much survived |
|
1195 |
|
1196 // We use the tenuring threshold to equalize the cost of major |
|
1197 // and minor collections. |
|
1198 // ThresholdTolerance is used to indicate how sensitive the |
|
1199 // tenuring threshold is to differences in cost betweent the |
|
1200 // collection types. |
|
1201 |
|
1202 // Get the times of interest. This involves a little work, so |
|
1203 // we cache the values here. |
|
1204 const double major_cost = major_gc_cost(); |
|
1205 const double minor_cost = minor_gc_cost(); |
|
1206 |
|
1207 if (minor_cost > major_cost * _threshold_tolerance_percent) { |
|
1208 // Minor times are getting too long; lower the threshold so |
|
1209 // less survives and more is promoted. |
|
1210 decr_tenuring_threshold = true; |
|
1211 set_decrement_tenuring_threshold_for_gc_cost(true); |
|
1212 } else if (major_cost > minor_cost * _threshold_tolerance_percent) { |
|
1213 // Major times are too long, so we want less promotion. |
|
1214 incr_tenuring_threshold = true; |
|
1215 set_increment_tenuring_threshold_for_gc_cost(true); |
|
1216 } |
|
1217 |
|
1218 } else { |
|
1219 // Survivor space overflow occurred, so promoted and survived are |
|
1220 // not accurate. We'll make our best guess by combining survived |
|
1221 // and promoted and count them as survivors. |
|
1222 // |
|
1223 // We'll lower the tenuring threshold to see if we can correct |
|
1224 // things. Also, set the survivor size conservatively. We're |
|
1225 // trying to avoid many overflows from occurring if defnew size |
|
1226 // is just too small. |
|
1227 |
|
1228 decr_tenuring_threshold = true; |
|
1229 } |
|
1230 |
|
1231 // The padded average also maintains a deviation from the average; |
|
1232 // we use this to see how good of an estimate we have of what survived. |
|
1233 // We're trying to pad the survivor size as little as possible without |
|
1234 // overflowing the survivor spaces. |
|
1235 size_t target_size = align_size_up((size_t)_avg_survived->padded_average(), |
|
1236 _space_alignment); |
|
1237 target_size = MAX2(target_size, _space_alignment); |
|
1238 |
|
1239 if (target_size > survivor_limit) { |
|
1240 // Target size is bigger than we can handle. Let's also reduce |
|
1241 // the tenuring threshold. |
|
1242 target_size = survivor_limit; |
|
1243 decr_tenuring_threshold = true; |
|
1244 set_decrement_tenuring_threshold_for_survivor_limit(true); |
|
1245 } |
|
1246 |
|
1247 // Finally, increment or decrement the tenuring threshold, as decided above. |
|
1248 // We test for decrementing first, as we might have hit the target size |
|
1249 // limit. |
|
1250 if (decr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { |
|
1251 if (tenuring_threshold > 1) { |
|
1252 tenuring_threshold--; |
|
1253 } |
|
1254 } else if (incr_tenuring_threshold && !(AlwaysTenure || NeverTenure)) { |
|
1255 if (tenuring_threshold < MaxTenuringThreshold) { |
|
1256 tenuring_threshold++; |
|
1257 } |
|
1258 } |
|
1259 |
|
1260 // We keep a running average of the amount promoted which is used |
|
1261 // to decide when we should collect the old generation (when |
|
1262 // the amount of old gen free space is less than what we expect to |
|
1263 // promote). |
|
1264 |
|
1265 if (PrintAdaptiveSizePolicy) { |
|
1266 // A little more detail if Verbose is on |
|
1267 if (Verbose) { |
|
1268 gclog_or_tty->print( " avg_survived: %f" |
|
1269 " avg_deviation: %f", |
|
1270 _avg_survived->average(), |
|
1271 _avg_survived->deviation()); |
|
1272 } |
|
1273 |
|
1274 gclog_or_tty->print( " avg_survived_padded_avg: %f", |
|
1275 _avg_survived->padded_average()); |
|
1276 |
|
1277 if (Verbose) { |
|
1278 gclog_or_tty->print( " avg_promoted_avg: %f" |
|
1279 " avg_promoted_dev: %f", |
|
1280 avg_promoted()->average(), |
|
1281 avg_promoted()->deviation()); |
|
1282 } |
|
1283 |
|
1284 gclog_or_tty->print_cr( " avg_promoted_padded_avg: %f" |
|
1285 " avg_pretenured_padded_avg: %f" |
|
1286 " tenuring_thresh: %d" |
|
1287 " target_size: " SIZE_FORMAT, |
|
1288 avg_promoted()->padded_average(), |
|
1289 _avg_pretenured->padded_average(), |
|
1290 tenuring_threshold, target_size); |
|
1291 } |
|
1292 |
|
1293 set_survivor_size(target_size); |
|
1294 |
|
1295 return tenuring_threshold; |
|
1296 } |
|
1297 |
|
1298 void PSAdaptiveSizePolicy::update_averages(bool is_survivor_overflow, |
|
1299 size_t survived, |
|
1300 size_t promoted) { |
|
1301 // Update averages |
|
1302 if (!is_survivor_overflow) { |
|
1303 // Keep running averages on how much survived |
|
1304 _avg_survived->sample(survived); |
|
1305 } else { |
|
1306 size_t survived_guess = survived + promoted; |
|
1307 _avg_survived->sample(survived_guess); |
|
1308 } |
|
1309 avg_promoted()->sample(promoted + _avg_pretenured->padded_average()); |
|
1310 |
|
1311 if (PrintAdaptiveSizePolicy) { |
|
1312 gclog_or_tty->print_cr( |
|
1313 "AdaptiveSizePolicy::update_averages:" |
|
1314 " survived: " SIZE_FORMAT |
|
1315 " promoted: " SIZE_FORMAT |
|
1316 " overflow: %s", |
|
1317 survived, promoted, is_survivor_overflow ? "true" : "false"); |
|
1318 } |
|
1319 } |
|
1320 |
|
1321 bool PSAdaptiveSizePolicy::print_adaptive_size_policy_on(outputStream* st) |
|
1322 const { |
|
1323 |
|
1324 if (!UseAdaptiveSizePolicy) return false; |
|
1325 |
|
1326 return AdaptiveSizePolicy::print_adaptive_size_policy_on( |
|
1327 st, |
|
1328 PSScavenge::tenuring_threshold()); |
|
1329 } |
|
1330 |
|
1331 #ifndef PRODUCT |
|
1332 |
|
1333 void TestOldFreeSpaceCalculation_test() { |
|
1334 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 20) == 25, "Calculation of free memory failed"); |
|
1335 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 50) == 100, "Calculation of free memory failed"); |
|
1336 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 60) == 150, "Calculation of free memory failed"); |
|
1337 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 75) == 300, "Calculation of free memory failed"); |
|
1338 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 20) == 100, "Calculation of free memory failed"); |
|
1339 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 50) == 400, "Calculation of free memory failed"); |
|
1340 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 60) == 600, "Calculation of free memory failed"); |
|
1341 assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 75) == 1200, "Calculation of free memory failed"); |
|
1342 } |
|
1343 |
|
1344 #endif /* !PRODUCT */ |