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/os.hpp" 29 #include "utilities/debug.hpp" 30 #include "utilities/numberSeq.hpp" 31 32 // Different defaults for different number of GC threads 33 // They were chosen by running GCOld and SPECjbb on debris with different 34 // numbers of GC threads and choosing them based on the results 35 36 // all the same 37 static double rs_length_diff_defaults[] = { 38 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 39 }; 40 41 static double cost_per_logged_card_ms_defaults[] = { 42 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015 43 }; 44 45 // all the same 46 static double young_cards_per_entry_ratio_defaults[] = { 47 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 48 }; 49 50 static double young_only_cost_per_remset_card_ms_defaults[] = { 51 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005 52 }; 53 54 static double cost_per_byte_ms_defaults[] = { 55 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009 56 }; 57 58 // these should be pretty consistent 59 static double constant_other_time_ms_defaults[] = { 60 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0 61 }; 62 63 64 static double young_other_cost_per_region_ms_defaults[] = { 65 0.3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1 66 }; 67 68 static double non_young_other_cost_per_region_ms_defaults[] = { 69 1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30 70 }; 71 72 G1Analytics::G1Analytics(const G1Predictions* predictor) : 73 _predictor(predictor), 74 _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), 75 _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), 76 _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)), 77 _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 78 _prev_collection_pause_end_ms(0.0), 79 _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)), 80 _cost_per_logged_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 81 _cost_scan_hcc_seq(new TruncatedSeq(TruncatedSeqLength)), 82 _young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)), 83 _mixed_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)), 84 _young_only_cost_per_remset_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 85 _mixed_cost_per_remset_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 86 _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 87 _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 88 _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 89 _non_young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 90 _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)), 91 _rs_length_seq(new TruncatedSeq(TruncatedSeqLength)), 92 _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)), 93 _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)), 94 _recent_avg_pause_time_ratio(0.0), 95 _last_pause_time_ratio(0.0) { 96 97 // Seed sequences with initial values. 98 _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime()); 99 _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0; 100 101 int index = MIN2(ParallelGCThreads - 1, 7u); 102 103 _rs_length_diff_seq->add(rs_length_diff_defaults[index]); 104 _cost_per_logged_card_ms_seq->add(cost_per_logged_card_ms_defaults[index]); 105 _cost_scan_hcc_seq->add(0.0); 106 _young_cards_per_entry_ratio_seq->add(young_cards_per_entry_ratio_defaults[index]); 107 _young_only_cost_per_remset_card_ms_seq->add(young_only_cost_per_remset_card_ms_defaults[index]); 108 _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]); 109 _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]); 110 _young_other_cost_per_region_ms_seq->add(young_other_cost_per_region_ms_defaults[index]); 111 _non_young_other_cost_per_region_ms_seq->add(non_young_other_cost_per_region_ms_defaults[index]); 112 113 // start conservatively (around 50ms is about right) 114 _concurrent_mark_remark_times_ms->add(0.05); 115 _concurrent_mark_cleanup_times_ms->add(0.20); 116 } 117 118 double G1Analytics::get_new_prediction(TruncatedSeq const* seq) const { 119 return _predictor->get_new_prediction(seq); 120 } 121 122 size_t G1Analytics::get_new_size_prediction(TruncatedSeq const* seq) const { 123 return (size_t)get_new_prediction(seq); 124 } 125 126 int G1Analytics::num_alloc_rate_ms() const { 127 return _alloc_rate_ms_seq->num(); 128 } 129 130 void G1Analytics::report_concurrent_mark_remark_times_ms(double ms) { 131 _concurrent_mark_remark_times_ms->add(ms); 132 } 133 134 void G1Analytics::report_alloc_rate_ms(double alloc_rate) { 135 _alloc_rate_ms_seq->add(alloc_rate); 136 } 137 138 void G1Analytics::compute_pause_time_ratio(double interval_ms, double pause_time_ms) { 139 _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum() / interval_ms; 140 if (_recent_avg_pause_time_ratio < 0.0 || 141 (_recent_avg_pause_time_ratio - 1.0 > 0.0)) { 142 // Clip ratio between 0.0 and 1.0, and continue. This will be fixed in 143 // CR 6902692 by redoing the manner in which the ratio is incrementally computed. 144 if (_recent_avg_pause_time_ratio < 0.0) { 145 _recent_avg_pause_time_ratio = 0.0; 146 } else { 147 assert(_recent_avg_pause_time_ratio - 1.0 > 0.0, "Ctl-point invariant"); 148 _recent_avg_pause_time_ratio = 1.0; 149 } 150 } 151 152 // Compute the ratio of just this last pause time to the entire time range stored 153 // in the vectors. Comparing this pause to the entire range, rather than only the 154 // most recent interval, has the effect of smoothing over a possible transient 'burst' 155 // of more frequent pauses that don't really reflect a change in heap occupancy. 156 // This reduces the likelihood of a needless heap expansion being triggered. 157 _last_pause_time_ratio = 158 (pause_time_ms * _recent_prev_end_times_for_all_gcs_sec->num()) / interval_ms; 159 } 160 161 void G1Analytics::report_cost_per_logged_card_ms(double cost_per_logged_card_ms) { 162 _cost_per_logged_card_ms_seq->add(cost_per_logged_card_ms); 163 } 164 165 void G1Analytics::report_cost_scan_hcc(double cost_scan_hcc) { 166 _cost_scan_hcc_seq->add(cost_scan_hcc); 167 } 168 169 void G1Analytics::report_cost_per_remset_card_ms(double cost_per_remset_card_ms, bool for_young_gc) { 170 if (for_young_gc) { 171 _young_only_cost_per_remset_card_ms_seq->add(cost_per_remset_card_ms); 172 } else { 173 _mixed_cost_per_remset_card_ms_seq->add(cost_per_remset_card_ms); 174 } 175 } 176 177 void G1Analytics::report_cards_per_entry_ratio(double cards_per_entry_ratio, bool for_young_gc) { 178 if (for_young_gc) { 179 _young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio); 180 } else { 181 _mixed_cards_per_entry_ratio_seq->add(cards_per_entry_ratio); 182 } 183 } 184 185 void G1Analytics::report_rs_length_diff(double rs_length_diff) { 186 _rs_length_diff_seq->add(rs_length_diff); 187 } 188 189 void G1Analytics::report_cost_per_byte_ms(double cost_per_byte_ms, bool mark_or_rebuild_in_progress) { 190 if (mark_or_rebuild_in_progress) { 191 _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms); 192 } else { 193 _cost_per_byte_ms_seq->add(cost_per_byte_ms); 194 } 195 } 196 197 void G1Analytics::report_young_other_cost_per_region_ms(double other_cost_per_region_ms) { 198 _young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms); 199 } 200 201 void G1Analytics::report_non_young_other_cost_per_region_ms(double other_cost_per_region_ms) { 202 _non_young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms); 203 } 204 205 void G1Analytics::report_constant_other_time_ms(double constant_other_time_ms) { 206 _constant_other_time_ms_seq->add(constant_other_time_ms); 207 } 208 209 void G1Analytics::report_pending_cards(double pending_cards) { 210 _pending_cards_seq->add(pending_cards); 211 } 212 213 void G1Analytics::report_rs_length(double rs_length) { 214 _rs_length_seq->add(rs_length); 215 } 216 217 size_t G1Analytics::predict_rs_length_diff() const { 218 return get_new_size_prediction(_rs_length_diff_seq); 219 } 220 221 double G1Analytics::predict_alloc_rate_ms() const { 222 return get_new_prediction(_alloc_rate_ms_seq); 223 } 224 225 double G1Analytics::predict_cost_per_logged_card_ms() const { 226 return get_new_prediction(_cost_per_logged_card_ms_seq); 227 } 228 229 double G1Analytics::predict_scan_hcc_ms() const { 230 return get_new_prediction(_cost_scan_hcc_seq); 231 } 232 233 double G1Analytics::predict_rs_update_time_ms(size_t pending_cards) const { 234 return pending_cards * predict_cost_per_logged_card_ms() + predict_scan_hcc_ms(); 235 } 236 237 double G1Analytics::predict_young_cards_per_entry_ratio() const { 238 return get_new_prediction(_young_cards_per_entry_ratio_seq); 239 } 240 241 double G1Analytics::predict_mixed_cards_per_entry_ratio() const { 242 if (_mixed_cards_per_entry_ratio_seq->num() < 2) { 243 return predict_young_cards_per_entry_ratio(); 244 } else { 245 return get_new_prediction(_mixed_cards_per_entry_ratio_seq); 246 } 247 } 248 249 size_t G1Analytics::predict_card_num(size_t rs_length, bool for_young_gc) const { 250 if (for_young_gc) { 251 return (size_t) (rs_length * predict_young_cards_per_entry_ratio()); 252 } else { 253 return (size_t) (rs_length * predict_mixed_cards_per_entry_ratio()); 254 } 255 } 256 257 double G1Analytics::predict_rs_scan_time_ms(size_t card_num, bool for_young_gc) const { 258 if (for_young_gc) { 259 return card_num * get_new_prediction(_young_only_cost_per_remset_card_ms_seq); 260 } else { 261 return predict_mixed_rs_scan_time_ms(card_num); 262 } 263 } 264 265 double G1Analytics::predict_mixed_rs_scan_time_ms(size_t card_num) const { 266 if (_mixed_cost_per_remset_card_ms_seq->num() < 3) { 267 return card_num * get_new_prediction(_young_only_cost_per_remset_card_ms_seq); 268 } else { 269 return card_num * get_new_prediction(_mixed_cost_per_remset_card_ms_seq); 270 } 271 } 272 273 double G1Analytics::predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) const { 274 if (_cost_per_byte_ms_during_cm_seq->num() < 3) { 275 return (1.1 * bytes_to_copy) * get_new_prediction(_cost_per_byte_ms_seq); 276 } else { 277 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_during_cm_seq); 278 } 279 } 280 281 double G1Analytics::predict_object_copy_time_ms(size_t bytes_to_copy, bool during_concurrent_mark) const { 282 if (during_concurrent_mark) { 283 return predict_object_copy_time_ms_during_cm(bytes_to_copy); 284 } else { 285 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_seq); 286 } 287 } 288 289 double G1Analytics::predict_cost_per_byte_ms() const { 290 return get_new_prediction(_cost_per_byte_ms_seq); 291 } 292 293 double G1Analytics::predict_constant_other_time_ms() const { 294 return get_new_prediction(_constant_other_time_ms_seq); 295 } 296 297 double G1Analytics::predict_young_other_time_ms(size_t young_num) const { 298 return young_num * get_new_prediction(_young_other_cost_per_region_ms_seq); 299 } 300 301 double G1Analytics::predict_non_young_other_time_ms(size_t non_young_num) const { 302 return non_young_num * get_new_prediction(_non_young_other_cost_per_region_ms_seq); 303 } 304 305 double G1Analytics::predict_remark_time_ms() const { 306 return get_new_prediction(_concurrent_mark_remark_times_ms); 307 } 308 309 double G1Analytics::predict_cleanup_time_ms() const { 310 return get_new_prediction(_concurrent_mark_cleanup_times_ms); 311 } 312 313 size_t G1Analytics::predict_rs_length() const { 314 return get_new_size_prediction(_rs_length_seq); 315 } 316 317 size_t G1Analytics::predict_pending_cards() const { 318 return get_new_size_prediction(_pending_cards_seq); 319 } 320 321 double G1Analytics::last_known_gc_end_time_sec() const { 322 return _recent_prev_end_times_for_all_gcs_sec->oldest(); 323 } 324 325 void G1Analytics::update_recent_gc_times(double end_time_sec, 326 double pause_time_ms) { 327 _recent_gc_times_ms->add(pause_time_ms); 328 _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec); 329 _prev_collection_pause_end_ms = end_time_sec * 1000.0; 330 } 331 332 void G1Analytics::report_concurrent_mark_cleanup_times_ms(double ms) { 333 _concurrent_mark_cleanup_times_ms->add(ms); 334 }