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/numberSeq.hpp" 32 33 // Different defaults for different number of GC threads 34 // They were chosen by running GCOld and SPECjbb on debris with different 35 // numbers of GC threads and choosing them based on the results 36 37 // all the same 38 static double rs_length_diff_defaults[] = { 39 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 40 }; 41 42 static double cost_per_logged_card_ms_defaults[] = { 43 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015 44 }; 45 46 // all the same 47 static double young_card_merge_to_scan_ratio_defaults[] = { 48 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 49 }; 50 51 static double young_only_cost_per_card_scan_ms_defaults[] = { 52 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005 53 }; 54 55 static double cost_per_byte_ms_defaults[] = { 56 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009 57 }; 58 59 // these should be pretty consistent 60 static double constant_other_time_ms_defaults[] = { 61 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0 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 _concurrent_refine_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 81 _logged_cards_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 82 _young_card_merge_to_scan_ratio_seq(new TruncatedSeq(TruncatedSeqLength)), 83 _mixed_card_merge_to_scan_ratio_seq(new TruncatedSeq(TruncatedSeqLength)), 84 _young_cost_per_card_scan_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 85 _mixed_cost_per_card_scan_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 86 _young_cost_per_card_merge_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 87 _mixed_cost_per_card_merge_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 88 _copy_cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 89 _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 90 _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 91 _non_young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 92 _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)), 93 _rs_length_seq(new TruncatedSeq(TruncatedSeqLength)), 94 _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)), 95 _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)), 96 _recent_avg_pause_time_ratio(0.0), 97 _last_pause_time_ratio(0.0) { 98 99 // Seed sequences with initial values. 100 _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime()); 101 _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0; 102 103 int index = MIN2(ParallelGCThreads - 1, 7u); 104 105 _rs_length_diff_seq->add(rs_length_diff_defaults[index]); 106 // Start with inverse of maximum STW cost. 107 _concurrent_refine_rate_ms_seq->add(1/cost_per_logged_card_ms_defaults[0]); 108 // Some applications have very low rates for logging cards. 109 _logged_cards_rate_ms_seq->add(0.0); 110 _young_card_merge_to_scan_ratio_seq->add(young_card_merge_to_scan_ratio_defaults[index]); 111 _young_cost_per_card_scan_ms_seq->add(young_only_cost_per_card_scan_ms_defaults[index]); 112 113 _copy_cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]); 114 _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]); 115 _young_other_cost_per_region_ms_seq->add(young_other_cost_per_region_ms_defaults[index]); 116 _non_young_other_cost_per_region_ms_seq->add(non_young_other_cost_per_region_ms_defaults[index]); 117 118 // start conservatively (around 50ms is about right) 119 _concurrent_mark_remark_times_ms->add(0.05); 120 _concurrent_mark_cleanup_times_ms->add(0.20); 121 } 122 123 double G1Analytics::get_new_prediction(TruncatedSeq const* seq) const { 124 return _predictor->get_new_prediction(seq); 125 } 126 127 size_t G1Analytics::get_new_size_prediction(TruncatedSeq const* seq) const { 128 return (size_t)get_new_prediction(seq); 129 } 130 131 int G1Analytics::num_alloc_rate_ms() const { 132 return _alloc_rate_ms_seq->num(); 133 } 134 135 void G1Analytics::report_concurrent_mark_remark_times_ms(double ms) { 136 _concurrent_mark_remark_times_ms->add(ms); 137 } 138 139 void G1Analytics::report_alloc_rate_ms(double alloc_rate) { 140 _alloc_rate_ms_seq->add(alloc_rate); 141 } 142 143 void G1Analytics::compute_pause_time_ratio(double interval_ms, double pause_time_ms) { 144 _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum() / interval_ms; 145 if (_recent_avg_pause_time_ratio < 0.0 || 146 (_recent_avg_pause_time_ratio - 1.0 > 0.0)) { 147 // Clip ratio between 0.0 and 1.0, and continue. This will be fixed in 148 // CR 6902692 by redoing the manner in which the ratio is incrementally computed. 149 if (_recent_avg_pause_time_ratio < 0.0) { 150 _recent_avg_pause_time_ratio = 0.0; 151 } else { 152 assert(_recent_avg_pause_time_ratio - 1.0 > 0.0, "Ctl-point invariant"); 153 _recent_avg_pause_time_ratio = 1.0; 154 } 155 } 156 157 // Compute the ratio of just this last pause time to the entire time range stored 158 // in the vectors. Comparing this pause to the entire range, rather than only the 159 // most recent interval, has the effect of smoothing over a possible transient 'burst' 160 // of more frequent pauses that don't really reflect a change in heap occupancy. 161 // This reduces the likelihood of a needless heap expansion being triggered. 162 _last_pause_time_ratio = 163 (pause_time_ms * _recent_prev_end_times_for_all_gcs_sec->num()) / interval_ms; 164 } 165 166 void G1Analytics::report_concurrent_refine_rate_ms(double cards_per_ms) { 167 _concurrent_refine_rate_ms_seq->add(cards_per_ms); 168 } 169 170 void G1Analytics::report_logged_cards_rate_ms(double cards_per_ms) { 171 _logged_cards_rate_ms_seq->add(cards_per_ms); 172 } 173 174 void G1Analytics::report_cost_per_card_scan_ms(double cost_per_card_ms, bool for_young_gc) { 175 if (for_young_gc) { 176 _young_cost_per_card_scan_ms_seq->add(cost_per_card_ms); 177 } else { 178 _mixed_cost_per_card_scan_ms_seq->add(cost_per_card_ms); 179 } 180 } 181 182 void G1Analytics::report_cost_per_card_merge_ms(double cost_per_card_ms, bool for_young_gc) { 183 if (for_young_gc) { 184 _young_cost_per_card_merge_ms_seq->add(cost_per_card_ms); 185 } else { 186 _mixed_cost_per_card_merge_ms_seq->add(cost_per_card_ms); 187 } 188 } 189 190 void G1Analytics::report_card_merge_to_scan_ratio(double merge_to_scan_ratio, bool for_young_gc) { 191 if (for_young_gc) { 192 _young_card_merge_to_scan_ratio_seq->add(merge_to_scan_ratio); 193 } else { 194 _mixed_card_merge_to_scan_ratio_seq->add(merge_to_scan_ratio); 195 } 196 } 197 198 void G1Analytics::report_rs_length_diff(double rs_length_diff) { 199 _rs_length_diff_seq->add(rs_length_diff); 200 } 201 202 void G1Analytics::report_cost_per_byte_ms(double cost_per_byte_ms, bool mark_or_rebuild_in_progress) { 203 if (mark_or_rebuild_in_progress) { 204 _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms); 205 } else { 206 _copy_cost_per_byte_ms_seq->add(cost_per_byte_ms); 207 } 208 } 209 210 void G1Analytics::report_young_other_cost_per_region_ms(double other_cost_per_region_ms) { 211 _young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms); 212 } 213 214 void G1Analytics::report_non_young_other_cost_per_region_ms(double other_cost_per_region_ms) { 215 _non_young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms); 216 } 217 218 void G1Analytics::report_constant_other_time_ms(double constant_other_time_ms) { 219 _constant_other_time_ms_seq->add(constant_other_time_ms); 220 } 221 222 void G1Analytics::report_pending_cards(double pending_cards) { 223 _pending_cards_seq->add(pending_cards); 224 } 225 226 void G1Analytics::report_rs_length(double rs_length) { 227 _rs_length_seq->add(rs_length); 228 } 229 230 double G1Analytics::predict_alloc_rate_ms() const { 231 return get_new_prediction(_alloc_rate_ms_seq); 232 } 233 234 double G1Analytics::predict_concurrent_refine_rate_ms() const { 235 return get_new_prediction(_concurrent_refine_rate_ms_seq); 236 } 237 238 double G1Analytics::predict_logged_cards_rate_ms() const { 239 return get_new_prediction(_logged_cards_rate_ms_seq); 240 } 241 242 double G1Analytics::predict_young_card_merge_to_scan_ratio() const { 243 return get_new_prediction(_young_card_merge_to_scan_ratio_seq); 244 } 245 246 size_t G1Analytics::predict_scan_card_num(size_t rs_length, bool for_young_gc) const { 247 if (for_young_gc || _mixed_card_merge_to_scan_ratio_seq->num() < 3) { 248 return (size_t) (rs_length * predict_young_card_merge_to_scan_ratio()); 249 } else { 250 return (size_t) (rs_length * get_new_prediction(_mixed_card_merge_to_scan_ratio_seq)); 251 } 252 } 253 254 double G1Analytics::predict_card_merge_time_ms(size_t card_num, bool for_young_gc) const { 255 if (for_young_gc || _mixed_cost_per_card_merge_ms_seq->num() < 3) { 256 return card_num * get_new_prediction(_young_cost_per_card_merge_ms_seq); 257 } else { 258 return card_num * get_new_prediction(_mixed_cost_per_card_merge_ms_seq); 259 } 260 } 261 262 double G1Analytics::predict_card_scan_time_ms(size_t card_num, bool for_young_gc) const { 263 if (for_young_gc || _mixed_cost_per_card_scan_ms_seq->num() < 3) { 264 return card_num * get_new_prediction(_young_cost_per_card_scan_ms_seq); 265 } else { 266 return card_num * get_new_prediction(_mixed_cost_per_card_scan_ms_seq); 267 } 268 } 269 270 double G1Analytics::predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) const { 271 if (_cost_per_byte_ms_during_cm_seq->num() < 3) { 272 return (1.1 * bytes_to_copy) * get_new_prediction(_copy_cost_per_byte_ms_seq); 273 } else { 274 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_during_cm_seq); 275 } 276 } 277 278 double G1Analytics::predict_object_copy_time_ms(size_t bytes_to_copy, bool during_concurrent_mark) const { 279 if (during_concurrent_mark) { 280 return predict_object_copy_time_ms_during_cm(bytes_to_copy); 281 } else { 282 return bytes_to_copy * get_new_prediction(_copy_cost_per_byte_ms_seq); 283 } 284 } 285 286 double G1Analytics::predict_constant_other_time_ms() const { 287 return get_new_prediction(_constant_other_time_ms_seq); 288 } 289 290 double G1Analytics::predict_young_other_time_ms(size_t young_num) const { 291 return young_num * get_new_prediction(_young_other_cost_per_region_ms_seq); 292 } 293 294 double G1Analytics::predict_non_young_other_time_ms(size_t non_young_num) const { 295 return non_young_num * get_new_prediction(_non_young_other_cost_per_region_ms_seq); 296 } 297 298 double G1Analytics::predict_remark_time_ms() const { 299 return get_new_prediction(_concurrent_mark_remark_times_ms); 300 } 301 302 double G1Analytics::predict_cleanup_time_ms() const { 303 return get_new_prediction(_concurrent_mark_cleanup_times_ms); 304 } 305 306 size_t G1Analytics::predict_rs_length() const { 307 return get_new_size_prediction(_rs_length_seq) + get_new_prediction(_rs_length_diff_seq); 308 } 309 310 size_t G1Analytics::predict_pending_cards() const { 311 return get_new_size_prediction(_pending_cards_seq); 312 } 313 314 double G1Analytics::last_known_gc_end_time_sec() const { 315 return _recent_prev_end_times_for_all_gcs_sec->oldest(); 316 } 317 318 void G1Analytics::update_recent_gc_times(double end_time_sec, 319 double pause_time_ms) { 320 _recent_gc_times_ms->add(pause_time_ms); 321 _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec); 322 _prev_collection_pause_end_ms = end_time_sec * 1000.0; 323 } 324 325 void G1Analytics::report_concurrent_mark_cleanup_times_ms(double ms) { 326 _concurrent_mark_cleanup_times_ms->add(ms); 327 }