1 /* 2 * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc/g1/g1Analytics.hpp" 27 #include "gc/g1/g1Predictions.hpp" 28 #include "runtime/globals.hpp" 29 #include "runtime/os.hpp" 30 #include "utilities/debug.hpp" 31 #include "utilities/globalDefinitions.hpp" 32 #include "utilities/numberSeq.hpp" 33 34 // Different defaults for different number of GC threads 35 // They were chosen by running GCOld and SPECjbb on debris with different 36 // numbers of GC threads and choosing them based on the results 37 38 // all the same 39 static double rs_length_diff_defaults[] = { 40 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 41 }; 42 43 static double cost_per_logged_card_ms_defaults[] = { 44 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015 45 }; 46 47 // all the same 48 static double young_card_merge_to_scan_ratio_defaults[] = { 49 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 50 }; 51 52 static double young_only_cost_per_card_scan_ms_defaults[] = { 53 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005 54 }; 55 56 static double cost_per_byte_ms_defaults[] = { 57 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009 58 }; 59 60 // these should be pretty consistent 61 static double constant_other_time_ms_defaults[] = { 62 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0 63 }; 64 65 static double young_other_cost_per_region_ms_defaults[] = { 66 0.3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1 67 }; 68 69 static double non_young_other_cost_per_region_ms_defaults[] = { 70 1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30 71 }; 72 73 G1Analytics::G1Analytics(const G1Predictions* predictor) : 74 _predictor(predictor), 75 _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), 76 _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), 77 _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), 78 _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 79 _prev_collection_pause_end_ms(0.0), 80 _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)), 81 _concurrent_refine_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 82 _logged_cards_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 83 _young_card_merge_to_scan_ratio_seq(new TruncatedSeq(TruncatedSeqLength)), 84 _mixed_card_merge_to_scan_ratio_seq(new TruncatedSeq(TruncatedSeqLength)), 85 _young_cost_per_card_scan_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 86 _mixed_cost_per_card_scan_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 87 _young_cost_per_card_merge_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 88 _mixed_cost_per_card_merge_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 89 _copy_cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 90 _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 91 _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 92 _non_young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 93 _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)), 94 _rs_length_seq(new TruncatedSeq(TruncatedSeqLength)), 95 _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)), 96 _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)), 97 _recent_avg_pause_time_ratio(0.0), 98 _last_pause_time_ratio(0.0) { 99 100 // Seed sequences with initial values. 101 _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime()); 102 _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0; 103 104 int index = MIN2(ParallelGCThreads - 1, 7u); 105 106 _rs_length_diff_seq->add(rs_length_diff_defaults[index]); 107 // Start with inverse of maximum STW cost. 108 _concurrent_refine_rate_ms_seq->add(1/cost_per_logged_card_ms_defaults[0]); 109 // Some applications have very low rates for logging cards. 110 _logged_cards_rate_ms_seq->add(0.0); 111 _young_card_merge_to_scan_ratio_seq->add(young_card_merge_to_scan_ratio_defaults[index]); 112 _young_cost_per_card_scan_ms_seq->add(young_only_cost_per_card_scan_ms_defaults[index]); 113 114 _copy_cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]); 115 _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]); 116 _young_other_cost_per_region_ms_seq->add(young_other_cost_per_region_ms_defaults[index]); 117 _non_young_other_cost_per_region_ms_seq->add(non_young_other_cost_per_region_ms_defaults[index]); 118 119 // start conservatively (around 50ms is about right) 120 _concurrent_mark_remark_times_ms->add(0.05); 121 _concurrent_mark_cleanup_times_ms->add(0.20); 122 } 123 124 bool G1Analytics::enough_samples_available(TruncatedSeq const* seq) const { 125 return seq->num() >= 3; 126 } 127 128 double G1Analytics::get_new_prediction(TruncatedSeq const* seq) const { 129 return _predictor->get_new_prediction(seq); 130 } 131 132 size_t G1Analytics::get_new_size_prediction(TruncatedSeq const* seq) const { 133 return (size_t)get_new_prediction(seq); 134 } 135 136 int G1Analytics::num_alloc_rate_ms() const { 137 return _alloc_rate_ms_seq->num(); 138 } 139 140 void G1Analytics::report_concurrent_mark_remark_times_ms(double ms) { 141 _concurrent_mark_remark_times_ms->add(ms); 142 } 143 144 void G1Analytics::report_alloc_rate_ms(double alloc_rate) { 145 _alloc_rate_ms_seq->add(alloc_rate); 146 } 147 148 void G1Analytics::compute_pause_time_ratio(double interval_ms, double pause_time_ms) { 149 _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum() / interval_ms; 150 151 // Clamp the result to [0.0 ... 1.0] to filter out nonsensical results due to bad input. 152 _recent_avg_pause_time_ratio = clamp(_recent_avg_pause_time_ratio, 0.0, 1.0); 153 154 // Compute the ratio of just this last pause time to the entire time range stored 155 // in the vectors. Comparing this pause to the entire range, rather than only the 156 // most recent interval, has the effect of smoothing over a possible transient 'burst' 157 // of more frequent pauses that don't really reflect a change in heap occupancy. 158 // This reduces the likelihood of a needless heap expansion being triggered. 159 _last_pause_time_ratio = 160 (pause_time_ms * _recent_prev_end_times_for_all_gcs_sec->num()) / interval_ms; 161 } 162 163 void G1Analytics::report_concurrent_refine_rate_ms(double cards_per_ms) { 164 _concurrent_refine_rate_ms_seq->add(cards_per_ms); 165 } 166 167 void G1Analytics::report_logged_cards_rate_ms(double cards_per_ms) { 168 _logged_cards_rate_ms_seq->add(cards_per_ms); 169 } 170 171 void G1Analytics::report_cost_per_card_scan_ms(double cost_per_card_ms, bool for_young_gc) { 172 if (for_young_gc) { 173 _young_cost_per_card_scan_ms_seq->add(cost_per_card_ms); 174 } else { 175 _mixed_cost_per_card_scan_ms_seq->add(cost_per_card_ms); 176 } 177 } 178 179 void G1Analytics::report_cost_per_card_merge_ms(double cost_per_card_ms, bool for_young_gc) { 180 if (for_young_gc) { 181 _young_cost_per_card_merge_ms_seq->add(cost_per_card_ms); 182 } else { 183 _mixed_cost_per_card_merge_ms_seq->add(cost_per_card_ms); 184 } 185 } 186 187 void G1Analytics::report_card_merge_to_scan_ratio(double merge_to_scan_ratio, bool for_young_gc) { 188 if (for_young_gc) { 189 _young_card_merge_to_scan_ratio_seq->add(merge_to_scan_ratio); 190 } else { 191 _mixed_card_merge_to_scan_ratio_seq->add(merge_to_scan_ratio); 192 } 193 } 194 195 void G1Analytics::report_rs_length_diff(double rs_length_diff) { 196 _rs_length_diff_seq->add(rs_length_diff); 197 } 198 199 void G1Analytics::report_cost_per_byte_ms(double cost_per_byte_ms, bool mark_or_rebuild_in_progress) { 200 if (mark_or_rebuild_in_progress) { 201 _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms); 202 } else { 203 _copy_cost_per_byte_ms_seq->add(cost_per_byte_ms); 204 } 205 } 206 207 void G1Analytics::report_young_other_cost_per_region_ms(double other_cost_per_region_ms) { 208 _young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms); 209 } 210 211 void G1Analytics::report_non_young_other_cost_per_region_ms(double other_cost_per_region_ms) { 212 _non_young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms); 213 } 214 215 void G1Analytics::report_constant_other_time_ms(double constant_other_time_ms) { 216 _constant_other_time_ms_seq->add(constant_other_time_ms); 217 } 218 219 void G1Analytics::report_pending_cards(double pending_cards) { 220 _pending_cards_seq->add(pending_cards); 221 } 222 223 void G1Analytics::report_rs_length(double rs_length) { 224 _rs_length_seq->add(rs_length); 225 } 226 227 double G1Analytics::predict_alloc_rate_ms() const { 228 return get_new_prediction(_alloc_rate_ms_seq); 229 } 230 231 double G1Analytics::predict_concurrent_refine_rate_ms() const { 232 return get_new_prediction(_concurrent_refine_rate_ms_seq); 233 } 234 235 double G1Analytics::predict_logged_cards_rate_ms() const { 236 return get_new_prediction(_logged_cards_rate_ms_seq); 237 } 238 239 double G1Analytics::predict_young_card_merge_to_scan_ratio() const { 240 return get_new_prediction(_young_card_merge_to_scan_ratio_seq); 241 } 242 243 size_t G1Analytics::predict_scan_card_num(size_t rs_length, bool for_young_gc) const { 244 if (for_young_gc || !enough_samples_available(_mixed_card_merge_to_scan_ratio_seq)) { 245 return (size_t) (rs_length * predict_young_card_merge_to_scan_ratio()); 246 } else { 247 return (size_t) (rs_length * get_new_prediction(_mixed_card_merge_to_scan_ratio_seq)); 248 } 249 } 250 251 double G1Analytics::predict_card_merge_time_ms(size_t card_num, bool for_young_gc) const { 252 if (for_young_gc || !enough_samples_available(_mixed_cost_per_card_merge_ms_seq)) { 253 return card_num * get_new_prediction(_young_cost_per_card_merge_ms_seq); 254 } else { 255 return card_num * get_new_prediction(_mixed_cost_per_card_merge_ms_seq); 256 } 257 } 258 259 double G1Analytics::predict_card_scan_time_ms(size_t card_num, bool for_young_gc) const { 260 if (for_young_gc || !enough_samples_available(_mixed_cost_per_card_scan_ms_seq)) { 261 return card_num * get_new_prediction(_young_cost_per_card_scan_ms_seq); 262 } else { 263 return card_num * get_new_prediction(_mixed_cost_per_card_scan_ms_seq); 264 } 265 } 266 267 double G1Analytics::predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) const { 268 if (!enough_samples_available(_cost_per_byte_ms_during_cm_seq)) { 269 return (1.1 * bytes_to_copy) * get_new_prediction(_copy_cost_per_byte_ms_seq); 270 } else { 271 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_during_cm_seq); 272 } 273 } 274 275 double G1Analytics::predict_object_copy_time_ms(size_t bytes_to_copy, bool during_concurrent_mark) const { 276 if (during_concurrent_mark) { 277 return predict_object_copy_time_ms_during_cm(bytes_to_copy); 278 } else { 279 return bytes_to_copy * get_new_prediction(_copy_cost_per_byte_ms_seq); 280 } 281 } 282 283 double G1Analytics::predict_constant_other_time_ms() const { 284 return get_new_prediction(_constant_other_time_ms_seq); 285 } 286 287 double G1Analytics::predict_young_other_time_ms(size_t young_num) const { 288 return young_num * get_new_prediction(_young_other_cost_per_region_ms_seq); 289 } 290 291 double G1Analytics::predict_non_young_other_time_ms(size_t non_young_num) const { 292 return non_young_num * get_new_prediction(_non_young_other_cost_per_region_ms_seq); 293 } 294 295 double G1Analytics::predict_remark_time_ms() const { 296 return get_new_prediction(_concurrent_mark_remark_times_ms); 297 } 298 299 double G1Analytics::predict_cleanup_time_ms() const { 300 return get_new_prediction(_concurrent_mark_cleanup_times_ms); 301 } 302 303 size_t G1Analytics::predict_rs_length() const { 304 return get_new_size_prediction(_rs_length_seq) + get_new_prediction(_rs_length_diff_seq); 305 } 306 307 size_t G1Analytics::predict_pending_cards() const { 308 return get_new_size_prediction(_pending_cards_seq); 309 } 310 311 double G1Analytics::last_known_gc_end_time_sec() const { 312 return _recent_prev_end_times_for_all_gcs_sec->oldest(); 313 } 314 315 void G1Analytics::update_recent_gc_times(double end_time_sec, 316 double pause_time_ms) { 317 _recent_gc_times_ms->add(pause_time_ms); 318 _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec); 319 _prev_collection_pause_end_ms = end_time_sec * 1000.0; 320 } 321 322 void G1Analytics::report_concurrent_mark_cleanup_times_ms(double ms) { 323 _concurrent_mark_cleanup_times_ms->add(ms); 324 }