342
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1 /*
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2 * Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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20 * CA 95054 USA or visit www.sun.com if you need additional information or
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21 * have any questions.
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22 *
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23 */
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24
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25 // A G1CollectorPolicy makes policy decisions that determine the
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26 // characteristics of the collector. Examples include:
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27 // * choice of collection set.
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28 // * when to collect.
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29
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30 class HeapRegion;
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31 class CollectionSetChooser;
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32
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33 // Yes, this is a bit unpleasant... but it saves replicating the same thing
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34 // over and over again and introducing subtle problems through small typos and
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35 // cutting and pasting mistakes. The macros below introduces a number
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36 // sequnce into the following two classes and the methods that access it.
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37
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38 #define define_num_seq(name) \
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39 private: \
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40 NumberSeq _all_##name##_times_ms; \
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41 public: \
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42 void record_##name##_time_ms(double ms) { \
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43 _all_##name##_times_ms.add(ms); \
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44 } \
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45 NumberSeq* get_##name##_seq() { \
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46 return &_all_##name##_times_ms; \
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47 }
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48
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49 class MainBodySummary;
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50 class PopPreambleSummary;
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51
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52 class PauseSummary {
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53 define_num_seq(total)
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54 define_num_seq(other)
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55
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56 public:
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57 virtual MainBodySummary* main_body_summary() { return NULL; }
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58 virtual PopPreambleSummary* pop_preamble_summary() { return NULL; }
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59 };
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60
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61 class MainBodySummary {
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62 define_num_seq(satb_drain) // optional
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63 define_num_seq(parallel) // parallel only
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64 define_num_seq(ext_root_scan)
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65 define_num_seq(mark_stack_scan)
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66 define_num_seq(scan_only)
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67 define_num_seq(update_rs)
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68 define_num_seq(scan_rs)
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69 define_num_seq(scan_new_refs) // Only for temp use; added to
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70 // in parallel case.
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71 define_num_seq(obj_copy)
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72 define_num_seq(termination) // parallel only
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73 define_num_seq(parallel_other) // parallel only
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74 define_num_seq(mark_closure)
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75 define_num_seq(clear_ct) // parallel only
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76 };
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77
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78 class PopPreambleSummary {
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79 define_num_seq(pop_preamble)
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80 define_num_seq(pop_update_rs)
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81 define_num_seq(pop_scan_rs)
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82 define_num_seq(pop_closure_app)
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83 define_num_seq(pop_evacuation)
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84 define_num_seq(pop_other)
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85 };
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86
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87 class NonPopSummary: public PauseSummary,
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88 public MainBodySummary {
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89 public:
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90 virtual MainBodySummary* main_body_summary() { return this; }
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91 };
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92
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93 class PopSummary: public PauseSummary,
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94 public MainBodySummary,
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95 public PopPreambleSummary {
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96 public:
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97 virtual MainBodySummary* main_body_summary() { return this; }
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98 virtual PopPreambleSummary* pop_preamble_summary() { return this; }
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99 };
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100
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101 class NonPopAbandonedSummary: public PauseSummary {
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102 };
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103
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104 class PopAbandonedSummary: public PauseSummary,
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105 public PopPreambleSummary {
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106 public:
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107 virtual PopPreambleSummary* pop_preamble_summary() { return this; }
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108 };
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109
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110 class G1CollectorPolicy: public CollectorPolicy {
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111 protected:
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112 // The number of pauses during the execution.
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113 long _n_pauses;
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114
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115 // either equal to the number of parallel threads, if ParallelGCThreads
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116 // has been set, or 1 otherwise
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117 int _parallel_gc_threads;
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118
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119 enum SomePrivateConstants {
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120 NumPrevPausesForHeuristics = 10,
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121 NumPrevGCsForHeuristics = 10,
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122 NumAPIs = HeapRegion::MaxAge
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123 };
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124
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125 G1MMUTracker* _mmu_tracker;
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126
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127 void initialize_flags();
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128
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129 void initialize_all() {
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130 initialize_flags();
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131 initialize_size_info();
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132 initialize_perm_generation(PermGen::MarkSweepCompact);
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133 }
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134
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135 virtual size_t default_init_heap_size() {
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136 // Pick some reasonable default.
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137 return 8*M;
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138 }
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139
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140
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141 double _cur_collection_start_sec;
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142 size_t _cur_collection_pause_used_at_start_bytes;
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143 size_t _cur_collection_pause_used_regions_at_start;
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144 size_t _prev_collection_pause_used_at_end_bytes;
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145 double _cur_collection_par_time_ms;
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146 double _cur_satb_drain_time_ms;
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147 double _cur_clear_ct_time_ms;
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148 bool _satb_drain_time_set;
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149 double _cur_popular_preamble_start_ms;
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150 double _cur_popular_preamble_time_ms;
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151 double _cur_popular_compute_rc_time_ms;
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152 double _cur_popular_evac_time_ms;
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153
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154 double _cur_CH_strong_roots_end_sec;
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155 double _cur_CH_strong_roots_dur_ms;
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156 double _cur_G1_strong_roots_end_sec;
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157 double _cur_G1_strong_roots_dur_ms;
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158
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159 // Statistics for recent GC pauses. See below for how indexed.
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160 TruncatedSeq* _recent_CH_strong_roots_times_ms;
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161 TruncatedSeq* _recent_G1_strong_roots_times_ms;
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162 TruncatedSeq* _recent_evac_times_ms;
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163 // These exclude marking times.
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164 TruncatedSeq* _recent_pause_times_ms;
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165 TruncatedSeq* _recent_gc_times_ms;
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166
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167 TruncatedSeq* _recent_CS_bytes_used_before;
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168 TruncatedSeq* _recent_CS_bytes_surviving;
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169
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170 TruncatedSeq* _recent_rs_sizes;
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171
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172 TruncatedSeq* _concurrent_mark_init_times_ms;
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173 TruncatedSeq* _concurrent_mark_remark_times_ms;
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174 TruncatedSeq* _concurrent_mark_cleanup_times_ms;
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175
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176 NonPopSummary* _non_pop_summary;
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177 PopSummary* _pop_summary;
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178 NonPopAbandonedSummary* _non_pop_abandoned_summary;
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179 PopAbandonedSummary* _pop_abandoned_summary;
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180
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181 NumberSeq* _all_pause_times_ms;
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182 NumberSeq* _all_full_gc_times_ms;
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183 double _stop_world_start;
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184 NumberSeq* _all_stop_world_times_ms;
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185 NumberSeq* _all_yield_times_ms;
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186
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187 size_t _region_num_young;
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188 size_t _region_num_tenured;
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189 size_t _prev_region_num_young;
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190 size_t _prev_region_num_tenured;
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191
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192 NumberSeq* _all_mod_union_times_ms;
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193
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194 int _aux_num;
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195 NumberSeq* _all_aux_times_ms;
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196 double* _cur_aux_start_times_ms;
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197 double* _cur_aux_times_ms;
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198 bool* _cur_aux_times_set;
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199
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200 double* _par_last_ext_root_scan_times_ms;
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201 double* _par_last_mark_stack_scan_times_ms;
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202 double* _par_last_scan_only_times_ms;
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203 double* _par_last_scan_only_regions_scanned;
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204 double* _par_last_update_rs_start_times_ms;
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205 double* _par_last_update_rs_times_ms;
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206 double* _par_last_update_rs_processed_buffers;
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207 double* _par_last_scan_rs_start_times_ms;
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208 double* _par_last_scan_rs_times_ms;
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209 double* _par_last_scan_new_refs_times_ms;
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210 double* _par_last_obj_copy_times_ms;
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211 double* _par_last_termination_times_ms;
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212
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213 // there are two pases during popular pauses, so we need to store
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214 // somewhere the results of the first pass
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215 double* _pop_par_last_update_rs_start_times_ms;
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216 double* _pop_par_last_update_rs_times_ms;
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217 double* _pop_par_last_update_rs_processed_buffers;
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218 double* _pop_par_last_scan_rs_start_times_ms;
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219 double* _pop_par_last_scan_rs_times_ms;
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220 double* _pop_par_last_closure_app_times_ms;
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221
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222 double _pop_compute_rc_start;
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223 double _pop_evac_start;
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224
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225 // indicates that we are in young GC mode
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226 bool _in_young_gc_mode;
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227
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228 // indicates whether we are in full young or partially young GC mode
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229 bool _full_young_gcs;
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230
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231 // if true, then it tries to dynamically adjust the length of the
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232 // young list
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233 bool _adaptive_young_list_length;
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234 size_t _young_list_min_length;
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235 size_t _young_list_target_length;
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236 size_t _young_list_so_prefix_length;
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237 size_t _young_list_fixed_length;
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238
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239 size_t _young_cset_length;
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240 bool _last_young_gc_full;
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241
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242 double _target_pause_time_ms;
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243
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244 unsigned _full_young_pause_num;
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245 unsigned _partial_young_pause_num;
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246
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247 bool _during_marking;
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248 bool _in_marking_window;
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249 bool _in_marking_window_im;
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250
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251 SurvRateGroup* _short_lived_surv_rate_group;
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252 SurvRateGroup* _survivor_surv_rate_group;
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253 // add here any more surv rate groups
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254
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255 bool during_marking() {
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256 return _during_marking;
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257 }
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258
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259 // <NEW PREDICTION>
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260
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261 private:
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262 enum PredictionConstants {
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263 TruncatedSeqLength = 10
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264 };
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265
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266 TruncatedSeq* _alloc_rate_ms_seq;
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267 double _prev_collection_pause_end_ms;
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268
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269 TruncatedSeq* _pending_card_diff_seq;
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270 TruncatedSeq* _rs_length_diff_seq;
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271 TruncatedSeq* _cost_per_card_ms_seq;
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272 TruncatedSeq* _cost_per_scan_only_region_ms_seq;
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273 TruncatedSeq* _fully_young_cards_per_entry_ratio_seq;
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274 TruncatedSeq* _partially_young_cards_per_entry_ratio_seq;
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275 TruncatedSeq* _cost_per_entry_ms_seq;
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276 TruncatedSeq* _partially_young_cost_per_entry_ms_seq;
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277 TruncatedSeq* _cost_per_byte_ms_seq;
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278 TruncatedSeq* _constant_other_time_ms_seq;
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279 TruncatedSeq* _young_other_cost_per_region_ms_seq;
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280 TruncatedSeq* _non_young_other_cost_per_region_ms_seq;
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281
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282 TruncatedSeq* _pending_cards_seq;
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283 TruncatedSeq* _scanned_cards_seq;
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284 TruncatedSeq* _rs_lengths_seq;
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285
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286 TruncatedSeq* _cost_per_byte_ms_during_cm_seq;
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287 TruncatedSeq* _cost_per_scan_only_region_ms_during_cm_seq;
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288
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289 TruncatedSeq* _young_gc_eff_seq;
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290
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291 TruncatedSeq* _max_conc_overhead_seq;
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292
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293 size_t _recorded_young_regions;
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294 size_t _recorded_scan_only_regions;
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295 size_t _recorded_non_young_regions;
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296 size_t _recorded_region_num;
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297
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298 size_t _free_regions_at_end_of_collection;
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299 size_t _scan_only_regions_at_end_of_collection;
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300
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301 size_t _recorded_rs_lengths;
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302 size_t _max_rs_lengths;
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303
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304 size_t _recorded_marked_bytes;
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305 size_t _recorded_young_bytes;
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306
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307 size_t _predicted_pending_cards;
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308 size_t _predicted_cards_scanned;
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309 size_t _predicted_rs_lengths;
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310 size_t _predicted_bytes_to_copy;
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311
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312 double _predicted_survival_ratio;
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313 double _predicted_rs_update_time_ms;
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314 double _predicted_rs_scan_time_ms;
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315 double _predicted_scan_only_scan_time_ms;
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316 double _predicted_object_copy_time_ms;
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317 double _predicted_constant_other_time_ms;
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318 double _predicted_young_other_time_ms;
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319 double _predicted_non_young_other_time_ms;
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320 double _predicted_pause_time_ms;
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321
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322 double _vtime_diff_ms;
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323
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324 double _recorded_young_free_cset_time_ms;
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325 double _recorded_non_young_free_cset_time_ms;
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326
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327 double _sigma;
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328 double _expensive_region_limit_ms;
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329
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330 size_t _rs_lengths_prediction;
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331
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332 size_t _known_garbage_bytes;
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333 double _known_garbage_ratio;
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334
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335 double sigma() {
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336 return _sigma;
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337 }
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338
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339 // A function that prevents us putting too much stock in small sample
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340 // sets. Returns a number between 2.0 and 1.0, depending on the number
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341 // of samples. 5 or more samples yields one; fewer scales linearly from
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342 // 2.0 at 1 sample to 1.0 at 5.
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343 double confidence_factor(int samples) {
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344 if (samples > 4) return 1.0;
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345 else return 1.0 + sigma() * ((double)(5 - samples))/2.0;
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346 }
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347
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348 double get_new_neg_prediction(TruncatedSeq* seq) {
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349 return seq->davg() - sigma() * seq->dsd();
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350 }
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351
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352 #ifndef PRODUCT
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353 bool verify_young_ages(HeapRegion* head, SurvRateGroup *surv_rate_group);
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354 #endif // PRODUCT
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355
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356 protected:
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357 double _pause_time_target_ms;
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358 double _recorded_young_cset_choice_time_ms;
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359 double _recorded_non_young_cset_choice_time_ms;
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360 bool _within_target;
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361 size_t _pending_cards;
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362 size_t _max_pending_cards;
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363
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364 public:
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365
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366 void set_region_short_lived(HeapRegion* hr) {
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367 hr->install_surv_rate_group(_short_lived_surv_rate_group);
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368 }
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369
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370 void set_region_survivors(HeapRegion* hr) {
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371 hr->install_surv_rate_group(_survivor_surv_rate_group);
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372 }
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373
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374 #ifndef PRODUCT
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375 bool verify_young_ages();
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376 #endif // PRODUCT
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377
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378 void tag_scan_only(size_t short_lived_scan_only_length);
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379
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380 double get_new_prediction(TruncatedSeq* seq) {
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381 return MAX2(seq->davg() + sigma() * seq->dsd(),
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382 seq->davg() * confidence_factor(seq->num()));
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383 }
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384
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385 size_t young_cset_length() {
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386 return _young_cset_length;
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387 }
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388
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389 void record_max_rs_lengths(size_t rs_lengths) {
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390 _max_rs_lengths = rs_lengths;
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391 }
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392
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393 size_t predict_pending_card_diff() {
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394 double prediction = get_new_neg_prediction(_pending_card_diff_seq);
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395 if (prediction < 0.00001)
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396 return 0;
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397 else
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398 return (size_t) prediction;
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399 }
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400
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401 size_t predict_pending_cards() {
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402 size_t max_pending_card_num = _g1->max_pending_card_num();
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403 size_t diff = predict_pending_card_diff();
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404 size_t prediction;
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405 if (diff > max_pending_card_num)
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406 prediction = max_pending_card_num;
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407 else
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408 prediction = max_pending_card_num - diff;
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409
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410 return prediction;
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411 }
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412
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413 size_t predict_rs_length_diff() {
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414 return (size_t) get_new_prediction(_rs_length_diff_seq);
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415 }
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416
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417 double predict_alloc_rate_ms() {
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418 return get_new_prediction(_alloc_rate_ms_seq);
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419 }
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420
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421 double predict_cost_per_card_ms() {
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422 return get_new_prediction(_cost_per_card_ms_seq);
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423 }
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424
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425 double predict_rs_update_time_ms(size_t pending_cards) {
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426 return (double) pending_cards * predict_cost_per_card_ms();
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427 }
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428
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429 double predict_fully_young_cards_per_entry_ratio() {
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430 return get_new_prediction(_fully_young_cards_per_entry_ratio_seq);
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431 }
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432
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433 double predict_partially_young_cards_per_entry_ratio() {
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434 if (_partially_young_cards_per_entry_ratio_seq->num() < 2)
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435 return predict_fully_young_cards_per_entry_ratio();
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436 else
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437 return get_new_prediction(_partially_young_cards_per_entry_ratio_seq);
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438 }
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439
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440 size_t predict_young_card_num(size_t rs_length) {
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441 return (size_t) ((double) rs_length *
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442 predict_fully_young_cards_per_entry_ratio());
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443 }
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444
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445 size_t predict_non_young_card_num(size_t rs_length) {
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446 return (size_t) ((double) rs_length *
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447 predict_partially_young_cards_per_entry_ratio());
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448 }
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449
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450 double predict_rs_scan_time_ms(size_t card_num) {
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451 if (full_young_gcs())
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452 return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq);
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453 else
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454 return predict_partially_young_rs_scan_time_ms(card_num);
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455 }
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456
|
|
457 double predict_partially_young_rs_scan_time_ms(size_t card_num) {
|
|
458 if (_partially_young_cost_per_entry_ms_seq->num() < 3)
|
|
459 return (double) card_num * get_new_prediction(_cost_per_entry_ms_seq);
|
|
460 else
|
|
461 return (double) card_num *
|
|
462 get_new_prediction(_partially_young_cost_per_entry_ms_seq);
|
|
463 }
|
|
464
|
|
465 double predict_scan_only_time_ms_during_cm(size_t scan_only_region_num) {
|
|
466 if (_cost_per_scan_only_region_ms_during_cm_seq->num() < 3)
|
|
467 return 1.5 * (double) scan_only_region_num *
|
|
468 get_new_prediction(_cost_per_scan_only_region_ms_seq);
|
|
469 else
|
|
470 return (double) scan_only_region_num *
|
|
471 get_new_prediction(_cost_per_scan_only_region_ms_during_cm_seq);
|
|
472 }
|
|
473
|
|
474 double predict_scan_only_time_ms(size_t scan_only_region_num) {
|
|
475 if (_in_marking_window_im)
|
|
476 return predict_scan_only_time_ms_during_cm(scan_only_region_num);
|
|
477 else
|
|
478 return (double) scan_only_region_num *
|
|
479 get_new_prediction(_cost_per_scan_only_region_ms_seq);
|
|
480 }
|
|
481
|
|
482 double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) {
|
|
483 if (_cost_per_byte_ms_during_cm_seq->num() < 3)
|
|
484 return 1.1 * (double) bytes_to_copy *
|
|
485 get_new_prediction(_cost_per_byte_ms_seq);
|
|
486 else
|
|
487 return (double) bytes_to_copy *
|
|
488 get_new_prediction(_cost_per_byte_ms_during_cm_seq);
|
|
489 }
|
|
490
|
|
491 double predict_object_copy_time_ms(size_t bytes_to_copy) {
|
|
492 if (_in_marking_window && !_in_marking_window_im)
|
|
493 return predict_object_copy_time_ms_during_cm(bytes_to_copy);
|
|
494 else
|
|
495 return (double) bytes_to_copy *
|
|
496 get_new_prediction(_cost_per_byte_ms_seq);
|
|
497 }
|
|
498
|
|
499 double predict_constant_other_time_ms() {
|
|
500 return get_new_prediction(_constant_other_time_ms_seq);
|
|
501 }
|
|
502
|
|
503 double predict_young_other_time_ms(size_t young_num) {
|
|
504 return
|
|
505 (double) young_num *
|
|
506 get_new_prediction(_young_other_cost_per_region_ms_seq);
|
|
507 }
|
|
508
|
|
509 double predict_non_young_other_time_ms(size_t non_young_num) {
|
|
510 return
|
|
511 (double) non_young_num *
|
|
512 get_new_prediction(_non_young_other_cost_per_region_ms_seq);
|
|
513 }
|
|
514
|
|
515 void check_if_region_is_too_expensive(double predicted_time_ms);
|
|
516
|
|
517 double predict_young_collection_elapsed_time_ms(size_t adjustment);
|
|
518 double predict_base_elapsed_time_ms(size_t pending_cards);
|
|
519 double predict_base_elapsed_time_ms(size_t pending_cards,
|
|
520 size_t scanned_cards);
|
|
521 size_t predict_bytes_to_copy(HeapRegion* hr);
|
|
522 double predict_region_elapsed_time_ms(HeapRegion* hr, bool young);
|
|
523
|
|
524 // for use by: calculate_optimal_so_length(length)
|
|
525 void predict_gc_eff(size_t young_region_num,
|
|
526 size_t so_length,
|
|
527 double base_time_ms,
|
|
528 double *gc_eff,
|
|
529 double *pause_time_ms);
|
|
530
|
|
531 // for use by: calculate_young_list_target_config(rs_length)
|
|
532 bool predict_gc_eff(size_t young_region_num,
|
|
533 size_t so_length,
|
|
534 double base_time_with_so_ms,
|
|
535 size_t init_free_regions,
|
|
536 double target_pause_time_ms,
|
|
537 double* gc_eff);
|
|
538
|
|
539 void start_recording_regions();
|
|
540 void record_cset_region(HeapRegion* hr, bool young);
|
|
541 void record_scan_only_regions(size_t scan_only_length);
|
|
542 void end_recording_regions();
|
|
543
|
|
544 void record_vtime_diff_ms(double vtime_diff_ms) {
|
|
545 _vtime_diff_ms = vtime_diff_ms;
|
|
546 }
|
|
547
|
|
548 void record_young_free_cset_time_ms(double time_ms) {
|
|
549 _recorded_young_free_cset_time_ms = time_ms;
|
|
550 }
|
|
551
|
|
552 void record_non_young_free_cset_time_ms(double time_ms) {
|
|
553 _recorded_non_young_free_cset_time_ms = time_ms;
|
|
554 }
|
|
555
|
|
556 double predict_young_gc_eff() {
|
|
557 return get_new_neg_prediction(_young_gc_eff_seq);
|
|
558 }
|
|
559
|
|
560 // </NEW PREDICTION>
|
|
561
|
|
562 public:
|
|
563 void cset_regions_freed() {
|
|
564 bool propagate = _last_young_gc_full && !_in_marking_window;
|
|
565 _short_lived_surv_rate_group->all_surviving_words_recorded(propagate);
|
|
566 _survivor_surv_rate_group->all_surviving_words_recorded(propagate);
|
|
567 // also call it on any more surv rate groups
|
|
568 }
|
|
569
|
|
570 void set_known_garbage_bytes(size_t known_garbage_bytes) {
|
|
571 _known_garbage_bytes = known_garbage_bytes;
|
|
572 size_t heap_bytes = _g1->capacity();
|
|
573 _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes;
|
|
574 }
|
|
575
|
|
576 void decrease_known_garbage_bytes(size_t known_garbage_bytes) {
|
|
577 guarantee( _known_garbage_bytes >= known_garbage_bytes, "invariant" );
|
|
578
|
|
579 _known_garbage_bytes -= known_garbage_bytes;
|
|
580 size_t heap_bytes = _g1->capacity();
|
|
581 _known_garbage_ratio = (double) _known_garbage_bytes / (double) heap_bytes;
|
|
582 }
|
|
583
|
|
584 G1MMUTracker* mmu_tracker() {
|
|
585 return _mmu_tracker;
|
|
586 }
|
|
587
|
|
588 double predict_init_time_ms() {
|
|
589 return get_new_prediction(_concurrent_mark_init_times_ms);
|
|
590 }
|
|
591
|
|
592 double predict_remark_time_ms() {
|
|
593 return get_new_prediction(_concurrent_mark_remark_times_ms);
|
|
594 }
|
|
595
|
|
596 double predict_cleanup_time_ms() {
|
|
597 return get_new_prediction(_concurrent_mark_cleanup_times_ms);
|
|
598 }
|
|
599
|
|
600 // Returns an estimate of the survival rate of the region at yg-age
|
|
601 // "yg_age".
|
|
602 double predict_yg_surv_rate(int age) {
|
|
603 TruncatedSeq* seq = _short_lived_surv_rate_group->get_seq(age);
|
|
604 if (seq->num() == 0)
|
|
605 gclog_or_tty->print("BARF! age is %d", age);
|
|
606 guarantee( seq->num() > 0, "invariant" );
|
|
607 double pred = get_new_prediction(seq);
|
|
608 if (pred > 1.0)
|
|
609 pred = 1.0;
|
|
610 return pred;
|
|
611 }
|
|
612
|
|
613 double accum_yg_surv_rate_pred(int age) {
|
|
614 return _short_lived_surv_rate_group->accum_surv_rate_pred(age);
|
|
615 }
|
|
616
|
|
617 protected:
|
|
618 void print_stats (int level, const char* str, double value);
|
|
619 void print_stats (int level, const char* str, int value);
|
|
620 void print_par_stats (int level, const char* str, double* data) {
|
|
621 print_par_stats(level, str, data, true);
|
|
622 }
|
|
623 void print_par_stats (int level, const char* str, double* data, bool summary);
|
|
624 void print_par_buffers (int level, const char* str, double* data, bool summary);
|
|
625
|
|
626 void check_other_times(int level,
|
|
627 NumberSeq* other_times_ms,
|
|
628 NumberSeq* calc_other_times_ms) const;
|
|
629
|
|
630 void print_summary (PauseSummary* stats) const;
|
|
631 void print_abandoned_summary(PauseSummary* non_pop_summary,
|
|
632 PauseSummary* pop_summary) const;
|
|
633
|
|
634 void print_summary (int level, const char* str, NumberSeq* seq) const;
|
|
635 void print_summary_sd (int level, const char* str, NumberSeq* seq) const;
|
|
636
|
|
637 double avg_value (double* data);
|
|
638 double max_value (double* data);
|
|
639 double sum_of_values (double* data);
|
|
640 double max_sum (double* data1, double* data2);
|
|
641
|
|
642 int _last_satb_drain_processed_buffers;
|
|
643 int _last_update_rs_processed_buffers;
|
|
644 double _last_pause_time_ms;
|
|
645
|
|
646 size_t _bytes_in_to_space_before_gc;
|
|
647 size_t _bytes_in_to_space_after_gc;
|
|
648 size_t bytes_in_to_space_during_gc() {
|
|
649 return
|
|
650 _bytes_in_to_space_after_gc - _bytes_in_to_space_before_gc;
|
|
651 }
|
|
652 size_t _bytes_in_collection_set_before_gc;
|
|
653 // Used to count used bytes in CS.
|
|
654 friend class CountCSClosure;
|
|
655
|
|
656 // Statistics kept per GC stoppage, pause or full.
|
|
657 TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec;
|
|
658
|
|
659 // We track markings.
|
|
660 int _num_markings;
|
|
661 double _mark_thread_startup_sec; // Time at startup of marking thread
|
|
662
|
|
663 // Add a new GC of the given duration and end time to the record.
|
|
664 void update_recent_gc_times(double end_time_sec, double elapsed_ms);
|
|
665
|
|
666 // The head of the list (via "next_in_collection_set()") representing the
|
|
667 // current collection set.
|
|
668 HeapRegion* _collection_set;
|
|
669 size_t _collection_set_size;
|
|
670 size_t _collection_set_bytes_used_before;
|
|
671
|
|
672 // Info about marking.
|
|
673 int _n_marks; // Sticky at 2, so we know when we've done at least 2.
|
|
674
|
|
675 // The number of collection pauses at the end of the last mark.
|
|
676 size_t _n_pauses_at_mark_end;
|
|
677
|
|
678 // ==== This section is for stats related to starting Conc Refinement on time.
|
|
679 size_t _conc_refine_enabled;
|
|
680 size_t _conc_refine_zero_traversals;
|
|
681 size_t _conc_refine_max_traversals;
|
|
682 // In # of heap regions.
|
|
683 size_t _conc_refine_current_delta;
|
|
684
|
|
685 // At the beginning of a collection pause, update the variables above,
|
|
686 // especially the "delta".
|
|
687 void update_conc_refine_data();
|
|
688 // ====
|
|
689
|
|
690 // Stash a pointer to the g1 heap.
|
|
691 G1CollectedHeap* _g1;
|
|
692
|
|
693 // The average time in ms per collection pause, averaged over recent pauses.
|
|
694 double recent_avg_time_for_pauses_ms();
|
|
695
|
|
696 // The average time in ms for processing CollectedHeap strong roots, per
|
|
697 // collection pause, averaged over recent pauses.
|
|
698 double recent_avg_time_for_CH_strong_ms();
|
|
699
|
|
700 // The average time in ms for processing the G1 remembered set, per
|
|
701 // pause, averaged over recent pauses.
|
|
702 double recent_avg_time_for_G1_strong_ms();
|
|
703
|
|
704 // The average time in ms for "evacuating followers", per pause, averaged
|
|
705 // over recent pauses.
|
|
706 double recent_avg_time_for_evac_ms();
|
|
707
|
|
708 // The number of "recent" GCs recorded in the number sequences
|
|
709 int number_of_recent_gcs();
|
|
710
|
|
711 // The average survival ratio, computed by the total number of bytes
|
|
712 // suriviving / total number of bytes before collection over the last
|
|
713 // several recent pauses.
|
|
714 double recent_avg_survival_fraction();
|
|
715 // The survival fraction of the most recent pause; if there have been no
|
|
716 // pauses, returns 1.0.
|
|
717 double last_survival_fraction();
|
|
718
|
|
719 // Returns a "conservative" estimate of the recent survival rate, i.e.,
|
|
720 // one that may be higher than "recent_avg_survival_fraction".
|
|
721 // This is conservative in several ways:
|
|
722 // If there have been few pauses, it will assume a potential high
|
|
723 // variance, and err on the side of caution.
|
|
724 // It puts a lower bound (currently 0.1) on the value it will return.
|
|
725 // To try to detect phase changes, if the most recent pause ("latest") has a
|
|
726 // higher-than average ("avg") survival rate, it returns that rate.
|
|
727 // "work" version is a utility function; young is restricted to young regions.
|
|
728 double conservative_avg_survival_fraction_work(double avg,
|
|
729 double latest);
|
|
730
|
|
731 // The arguments are the two sequences that keep track of the number of bytes
|
|
732 // surviving and the total number of bytes before collection, resp.,
|
|
733 // over the last evereal recent pauses
|
|
734 // Returns the survival rate for the category in the most recent pause.
|
|
735 // If there have been no pauses, returns 1.0.
|
|
736 double last_survival_fraction_work(TruncatedSeq* surviving,
|
|
737 TruncatedSeq* before);
|
|
738
|
|
739 // The arguments are the two sequences that keep track of the number of bytes
|
|
740 // surviving and the total number of bytes before collection, resp.,
|
|
741 // over the last several recent pauses
|
|
742 // Returns the average survival ration over the last several recent pauses
|
|
743 // If there have been no pauses, return 1.0
|
|
744 double recent_avg_survival_fraction_work(TruncatedSeq* surviving,
|
|
745 TruncatedSeq* before);
|
|
746
|
|
747 double conservative_avg_survival_fraction() {
|
|
748 double avg = recent_avg_survival_fraction();
|
|
749 double latest = last_survival_fraction();
|
|
750 return conservative_avg_survival_fraction_work(avg, latest);
|
|
751 }
|
|
752
|
|
753 // The ratio of gc time to elapsed time, computed over recent pauses.
|
|
754 double _recent_avg_pause_time_ratio;
|
|
755
|
|
756 double recent_avg_pause_time_ratio() {
|
|
757 return _recent_avg_pause_time_ratio;
|
|
758 }
|
|
759
|
|
760 // Number of pauses between concurrent marking.
|
|
761 size_t _pauses_btwn_concurrent_mark;
|
|
762
|
|
763 size_t _n_marks_since_last_pause;
|
|
764
|
|
765 // True iff CM has been initiated.
|
|
766 bool _conc_mark_initiated;
|
|
767
|
|
768 // True iff CM should be initiated
|
|
769 bool _should_initiate_conc_mark;
|
|
770 bool _should_revert_to_full_young_gcs;
|
|
771 bool _last_full_young_gc;
|
|
772
|
|
773 // This set of variables tracks the collector efficiency, in order to
|
|
774 // determine whether we should initiate a new marking.
|
|
775 double _cur_mark_stop_world_time_ms;
|
|
776 double _mark_init_start_sec;
|
|
777 double _mark_remark_start_sec;
|
|
778 double _mark_cleanup_start_sec;
|
|
779 double _mark_closure_time_ms;
|
|
780
|
|
781 void calculate_young_list_min_length();
|
|
782 void calculate_young_list_target_config();
|
|
783 void calculate_young_list_target_config(size_t rs_lengths);
|
|
784 size_t calculate_optimal_so_length(size_t young_list_length);
|
|
785
|
|
786 public:
|
|
787
|
|
788 G1CollectorPolicy();
|
|
789
|
|
790 virtual G1CollectorPolicy* as_g1_policy() { return this; }
|
|
791
|
|
792 virtual CollectorPolicy::Name kind() {
|
|
793 return CollectorPolicy::G1CollectorPolicyKind;
|
|
794 }
|
|
795
|
|
796 void check_prediction_validity();
|
|
797
|
|
798 size_t bytes_in_collection_set() {
|
|
799 return _bytes_in_collection_set_before_gc;
|
|
800 }
|
|
801
|
|
802 size_t bytes_in_to_space() {
|
|
803 return bytes_in_to_space_during_gc();
|
|
804 }
|
|
805
|
|
806 unsigned calc_gc_alloc_time_stamp() {
|
|
807 return _all_pause_times_ms->num() + 1;
|
|
808 }
|
|
809
|
|
810 protected:
|
|
811
|
|
812 // Count the number of bytes used in the CS.
|
|
813 void count_CS_bytes_used();
|
|
814
|
|
815 // Together these do the base cleanup-recording work. Subclasses might
|
|
816 // want to put something between them.
|
|
817 void record_concurrent_mark_cleanup_end_work1(size_t freed_bytes,
|
|
818 size_t max_live_bytes);
|
|
819 void record_concurrent_mark_cleanup_end_work2();
|
|
820
|
|
821 public:
|
|
822
|
|
823 virtual void init();
|
|
824
|
|
825 virtual HeapWord* mem_allocate_work(size_t size,
|
|
826 bool is_tlab,
|
|
827 bool* gc_overhead_limit_was_exceeded);
|
|
828
|
|
829 // This method controls how a collector handles one or more
|
|
830 // of its generations being fully allocated.
|
|
831 virtual HeapWord* satisfy_failed_allocation(size_t size,
|
|
832 bool is_tlab);
|
|
833
|
|
834 BarrierSet::Name barrier_set_name() { return BarrierSet::G1SATBCTLogging; }
|
|
835
|
|
836 GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; }
|
|
837
|
|
838 // The number of collection pauses so far.
|
|
839 long n_pauses() const { return _n_pauses; }
|
|
840
|
|
841 // Update the heuristic info to record a collection pause of the given
|
|
842 // start time, where the given number of bytes were used at the start.
|
|
843 // This may involve changing the desired size of a collection set.
|
|
844
|
|
845 virtual void record_stop_world_start();
|
|
846
|
|
847 virtual void record_collection_pause_start(double start_time_sec,
|
|
848 size_t start_used);
|
|
849
|
|
850 virtual void record_popular_pause_preamble_start();
|
|
851 virtual void record_popular_pause_preamble_end();
|
|
852
|
|
853 // Must currently be called while the world is stopped.
|
|
854 virtual void record_concurrent_mark_init_start();
|
|
855 virtual void record_concurrent_mark_init_end();
|
|
856 void record_concurrent_mark_init_end_pre(double
|
|
857 mark_init_elapsed_time_ms);
|
|
858
|
|
859 void record_mark_closure_time(double mark_closure_time_ms);
|
|
860
|
|
861 virtual void record_concurrent_mark_remark_start();
|
|
862 virtual void record_concurrent_mark_remark_end();
|
|
863
|
|
864 virtual void record_concurrent_mark_cleanup_start();
|
|
865 virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,
|
|
866 size_t max_live_bytes);
|
|
867 virtual void record_concurrent_mark_cleanup_completed();
|
|
868
|
|
869 virtual void record_concurrent_pause();
|
|
870 virtual void record_concurrent_pause_end();
|
|
871
|
|
872 virtual void record_collection_pause_end_CH_strong_roots();
|
|
873 virtual void record_collection_pause_end_G1_strong_roots();
|
|
874
|
|
875 virtual void record_collection_pause_end(bool popular, bool abandoned);
|
|
876
|
|
877 // Record the fact that a full collection occurred.
|
|
878 virtual void record_full_collection_start();
|
|
879 virtual void record_full_collection_end();
|
|
880
|
|
881 void record_ext_root_scan_time(int worker_i, double ms) {
|
|
882 _par_last_ext_root_scan_times_ms[worker_i] = ms;
|
|
883 }
|
|
884
|
|
885 void record_mark_stack_scan_time(int worker_i, double ms) {
|
|
886 _par_last_mark_stack_scan_times_ms[worker_i] = ms;
|
|
887 }
|
|
888
|
|
889 void record_scan_only_time(int worker_i, double ms, int n) {
|
|
890 _par_last_scan_only_times_ms[worker_i] = ms;
|
|
891 _par_last_scan_only_regions_scanned[worker_i] = (double) n;
|
|
892 }
|
|
893
|
|
894 void record_satb_drain_time(double ms) {
|
|
895 _cur_satb_drain_time_ms = ms;
|
|
896 _satb_drain_time_set = true;
|
|
897 }
|
|
898
|
|
899 void record_satb_drain_processed_buffers (int processed_buffers) {
|
|
900 _last_satb_drain_processed_buffers = processed_buffers;
|
|
901 }
|
|
902
|
|
903 void record_mod_union_time(double ms) {
|
|
904 _all_mod_union_times_ms->add(ms);
|
|
905 }
|
|
906
|
|
907 void record_update_rs_start_time(int thread, double ms) {
|
|
908 _par_last_update_rs_start_times_ms[thread] = ms;
|
|
909 }
|
|
910
|
|
911 void record_update_rs_time(int thread, double ms) {
|
|
912 _par_last_update_rs_times_ms[thread] = ms;
|
|
913 }
|
|
914
|
|
915 void record_update_rs_processed_buffers (int thread,
|
|
916 double processed_buffers) {
|
|
917 _par_last_update_rs_processed_buffers[thread] = processed_buffers;
|
|
918 }
|
|
919
|
|
920 void record_scan_rs_start_time(int thread, double ms) {
|
|
921 _par_last_scan_rs_start_times_ms[thread] = ms;
|
|
922 }
|
|
923
|
|
924 void record_scan_rs_time(int thread, double ms) {
|
|
925 _par_last_scan_rs_times_ms[thread] = ms;
|
|
926 }
|
|
927
|
|
928 void record_scan_new_refs_time(int thread, double ms) {
|
|
929 _par_last_scan_new_refs_times_ms[thread] = ms;
|
|
930 }
|
|
931
|
|
932 double get_scan_new_refs_time(int thread) {
|
|
933 return _par_last_scan_new_refs_times_ms[thread];
|
|
934 }
|
|
935
|
|
936 void reset_obj_copy_time(int thread) {
|
|
937 _par_last_obj_copy_times_ms[thread] = 0.0;
|
|
938 }
|
|
939
|
|
940 void reset_obj_copy_time() {
|
|
941 reset_obj_copy_time(0);
|
|
942 }
|
|
943
|
|
944 void record_obj_copy_time(int thread, double ms) {
|
|
945 _par_last_obj_copy_times_ms[thread] += ms;
|
|
946 }
|
|
947
|
|
948 void record_obj_copy_time(double ms) {
|
|
949 record_obj_copy_time(0, ms);
|
|
950 }
|
|
951
|
|
952 void record_termination_time(int thread, double ms) {
|
|
953 _par_last_termination_times_ms[thread] = ms;
|
|
954 }
|
|
955
|
|
956 void record_termination_time(double ms) {
|
|
957 record_termination_time(0, ms);
|
|
958 }
|
|
959
|
|
960 void record_pause_time(double ms) {
|
|
961 _last_pause_time_ms = ms;
|
|
962 }
|
|
963
|
|
964 void record_clear_ct_time(double ms) {
|
|
965 _cur_clear_ct_time_ms = ms;
|
|
966 }
|
|
967
|
|
968 void record_par_time(double ms) {
|
|
969 _cur_collection_par_time_ms = ms;
|
|
970 }
|
|
971
|
|
972 void record_aux_start_time(int i) {
|
|
973 guarantee(i < _aux_num, "should be within range");
|
|
974 _cur_aux_start_times_ms[i] = os::elapsedTime() * 1000.0;
|
|
975 }
|
|
976
|
|
977 void record_aux_end_time(int i) {
|
|
978 guarantee(i < _aux_num, "should be within range");
|
|
979 double ms = os::elapsedTime() * 1000.0 - _cur_aux_start_times_ms[i];
|
|
980 _cur_aux_times_set[i] = true;
|
|
981 _cur_aux_times_ms[i] += ms;
|
|
982 }
|
|
983
|
|
984 void record_pop_compute_rc_start();
|
|
985 void record_pop_compute_rc_end();
|
|
986
|
|
987 void record_pop_evac_start();
|
|
988 void record_pop_evac_end();
|
|
989
|
|
990 // Record the fact that "bytes" bytes allocated in a region.
|
|
991 void record_before_bytes(size_t bytes);
|
|
992 void record_after_bytes(size_t bytes);
|
|
993
|
|
994 // Returns "true" if this is a good time to do a collection pause.
|
|
995 // The "word_size" argument, if non-zero, indicates the size of an
|
|
996 // allocation request that is prompting this query.
|
|
997 virtual bool should_do_collection_pause(size_t word_size) = 0;
|
|
998
|
|
999 // Choose a new collection set. Marks the chosen regions as being
|
|
1000 // "in_collection_set", and links them together. The head and number of
|
|
1001 // the collection set are available via access methods.
|
|
1002 // If "pop_region" is non-NULL, it is a popular region that has already
|
|
1003 // been added to the collection set.
|
|
1004 virtual void choose_collection_set(HeapRegion* pop_region = NULL) = 0;
|
|
1005
|
|
1006 void clear_collection_set() { _collection_set = NULL; }
|
|
1007
|
|
1008 // The head of the list (via "next_in_collection_set()") representing the
|
|
1009 // current collection set.
|
|
1010 HeapRegion* collection_set() { return _collection_set; }
|
|
1011
|
|
1012 // Sets the collection set to the given single region.
|
|
1013 virtual void set_single_region_collection_set(HeapRegion* hr);
|
|
1014
|
|
1015 // The number of elements in the current collection set.
|
|
1016 size_t collection_set_size() { return _collection_set_size; }
|
|
1017
|
|
1018 // Add "hr" to the CS.
|
|
1019 void add_to_collection_set(HeapRegion* hr);
|
|
1020
|
|
1021 bool should_initiate_conc_mark() { return _should_initiate_conc_mark; }
|
|
1022 void set_should_initiate_conc_mark() { _should_initiate_conc_mark = true; }
|
|
1023 void unset_should_initiate_conc_mark(){ _should_initiate_conc_mark = false; }
|
|
1024
|
|
1025 void checkpoint_conc_overhead();
|
|
1026
|
|
1027 // If an expansion would be appropriate, because recent GC overhead had
|
|
1028 // exceeded the desired limit, return an amount to expand by.
|
|
1029 virtual size_t expansion_amount();
|
|
1030
|
|
1031 // note start of mark thread
|
|
1032 void note_start_of_mark_thread();
|
|
1033
|
|
1034 // The marked bytes of the "r" has changed; reclassify it's desirability
|
|
1035 // for marking. Also asserts that "r" is eligible for a CS.
|
|
1036 virtual void note_change_in_marked_bytes(HeapRegion* r) = 0;
|
|
1037
|
|
1038 #ifndef PRODUCT
|
|
1039 // Check any appropriate marked bytes info, asserting false if
|
|
1040 // something's wrong, else returning "true".
|
|
1041 virtual bool assertMarkedBytesDataOK() = 0;
|
|
1042 #endif
|
|
1043
|
|
1044 // Print tracing information.
|
|
1045 void print_tracing_info() const;
|
|
1046
|
|
1047 // Print stats on young survival ratio
|
|
1048 void print_yg_surv_rate_info() const;
|
|
1049
|
|
1050 void finished_recalculating_age_indexes() {
|
|
1051 _short_lived_surv_rate_group->finished_recalculating_age_indexes();
|
|
1052 // do that for any other surv rate groups
|
|
1053 }
|
|
1054
|
|
1055 bool should_add_next_region_to_young_list();
|
|
1056
|
|
1057 bool in_young_gc_mode() {
|
|
1058 return _in_young_gc_mode;
|
|
1059 }
|
|
1060 void set_in_young_gc_mode(bool in_young_gc_mode) {
|
|
1061 _in_young_gc_mode = in_young_gc_mode;
|
|
1062 }
|
|
1063
|
|
1064 bool full_young_gcs() {
|
|
1065 return _full_young_gcs;
|
|
1066 }
|
|
1067 void set_full_young_gcs(bool full_young_gcs) {
|
|
1068 _full_young_gcs = full_young_gcs;
|
|
1069 }
|
|
1070
|
|
1071 bool adaptive_young_list_length() {
|
|
1072 return _adaptive_young_list_length;
|
|
1073 }
|
|
1074 void set_adaptive_young_list_length(bool adaptive_young_list_length) {
|
|
1075 _adaptive_young_list_length = adaptive_young_list_length;
|
|
1076 }
|
|
1077
|
|
1078 inline double get_gc_eff_factor() {
|
|
1079 double ratio = _known_garbage_ratio;
|
|
1080
|
|
1081 double square = ratio * ratio;
|
|
1082 // square = square * square;
|
|
1083 double ret = square * 9.0 + 1.0;
|
|
1084 #if 0
|
|
1085 gclog_or_tty->print_cr("ratio = %1.2lf, ret = %1.2lf", ratio, ret);
|
|
1086 #endif // 0
|
|
1087 guarantee(0.0 <= ret && ret < 10.0, "invariant!");
|
|
1088 return ret;
|
|
1089 }
|
|
1090
|
|
1091 //
|
|
1092 // Survivor regions policy.
|
|
1093 //
|
|
1094 protected:
|
|
1095
|
|
1096 // Current tenuring threshold, set to 0 if the collector reaches the
|
|
1097 // maximum amount of suvivors regions.
|
|
1098 int _tenuring_threshold;
|
|
1099
|
|
1100 public:
|
|
1101
|
|
1102 inline GCAllocPurpose
|
|
1103 evacuation_destination(HeapRegion* src_region, int age, size_t word_sz) {
|
|
1104 if (age < _tenuring_threshold && src_region->is_young()) {
|
|
1105 return GCAllocForSurvived;
|
|
1106 } else {
|
|
1107 return GCAllocForTenured;
|
|
1108 }
|
|
1109 }
|
|
1110
|
|
1111 inline bool track_object_age(GCAllocPurpose purpose) {
|
|
1112 return purpose == GCAllocForSurvived;
|
|
1113 }
|
|
1114
|
|
1115 inline GCAllocPurpose alternative_purpose(int purpose) {
|
|
1116 return GCAllocForTenured;
|
|
1117 }
|
|
1118
|
|
1119 uint max_regions(int purpose);
|
|
1120
|
|
1121 // The limit on regions for a particular purpose is reached.
|
|
1122 void note_alloc_region_limit_reached(int purpose) {
|
|
1123 if (purpose == GCAllocForSurvived) {
|
|
1124 _tenuring_threshold = 0;
|
|
1125 }
|
|
1126 }
|
|
1127
|
|
1128 void note_start_adding_survivor_regions() {
|
|
1129 _survivor_surv_rate_group->start_adding_regions();
|
|
1130 }
|
|
1131
|
|
1132 void note_stop_adding_survivor_regions() {
|
|
1133 _survivor_surv_rate_group->stop_adding_regions();
|
|
1134 }
|
|
1135 };
|
|
1136
|
|
1137 // This encapsulates a particular strategy for a g1 Collector.
|
|
1138 //
|
|
1139 // Start a concurrent mark when our heap size is n bytes
|
|
1140 // greater then our heap size was at the last concurrent
|
|
1141 // mark. Where n is a function of the CMSTriggerRatio
|
|
1142 // and the MinHeapFreeRatio.
|
|
1143 //
|
|
1144 // Start a g1 collection pause when we have allocated the
|
|
1145 // average number of bytes currently being freed in
|
|
1146 // a collection, but only if it is at least one region
|
|
1147 // full
|
|
1148 //
|
|
1149 // Resize Heap based on desired
|
|
1150 // allocation space, where desired allocation space is
|
|
1151 // a function of survival rate and desired future to size.
|
|
1152 //
|
|
1153 // Choose collection set by first picking all older regions
|
|
1154 // which have a survival rate which beats our projected young
|
|
1155 // survival rate. Then fill out the number of needed regions
|
|
1156 // with young regions.
|
|
1157
|
|
1158 class G1CollectorPolicy_BestRegionsFirst: public G1CollectorPolicy {
|
|
1159 CollectionSetChooser* _collectionSetChooser;
|
|
1160 // If the estimated is less then desirable, resize if possible.
|
|
1161 void expand_if_possible(size_t numRegions);
|
|
1162
|
|
1163 virtual void choose_collection_set(HeapRegion* pop_region = NULL);
|
|
1164 virtual void record_collection_pause_start(double start_time_sec,
|
|
1165 size_t start_used);
|
|
1166 virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,
|
|
1167 size_t max_live_bytes);
|
|
1168 virtual void record_full_collection_end();
|
|
1169
|
|
1170 public:
|
|
1171 G1CollectorPolicy_BestRegionsFirst() {
|
|
1172 _collectionSetChooser = new CollectionSetChooser();
|
|
1173 }
|
|
1174 void record_collection_pause_end(bool popular, bool abandoned);
|
|
1175 bool should_do_collection_pause(size_t word_size);
|
|
1176 virtual void set_single_region_collection_set(HeapRegion* hr);
|
|
1177 // This is not needed any more, after the CSet choosing code was
|
|
1178 // changed to use the pause prediction work. But let's leave the
|
|
1179 // hook in just in case.
|
|
1180 void note_change_in_marked_bytes(HeapRegion* r) { }
|
|
1181 #ifndef PRODUCT
|
|
1182 bool assertMarkedBytesDataOK();
|
|
1183 #endif
|
|
1184 };
|
|
1185
|
|
1186 // This should move to some place more general...
|
|
1187
|
|
1188 // If we have "n" measurements, and we've kept track of their "sum" and the
|
|
1189 // "sum_of_squares" of the measurements, this returns the variance of the
|
|
1190 // sequence.
|
|
1191 inline double variance(int n, double sum_of_squares, double sum) {
|
|
1192 double n_d = (double)n;
|
|
1193 double avg = sum/n_d;
|
|
1194 return (sum_of_squares - 2.0 * avg * sum + n_d * avg * avg) / n_d;
|
|
1195 }
|
|
1196
|
|
1197 // Local Variables: ***
|
|
1198 // c-indentation-style: gnu ***
|
|
1199 // End: ***
|