1 /* 2 * Copyright (c) 2016, 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_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 cost_per_entry_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_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 _cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 85 _mixed_cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 86 _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 87 _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)), 88 _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 89 _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 90 _non_young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)), 91 _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)), 92 _rs_lengths_seq(new TruncatedSeq(TruncatedSeqLength)), 93 _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)) { 94 95 // Seed sequences with initial values. 96 _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime()); 97 _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0; 98 99 int index = MIN2(ParallelGCThreads - 1, 7u); 100 101 _rs_length_diff_seq->add(rs_length_diff_defaults[index]); 102 _cost_per_card_ms_seq->add(cost_per_card_ms_defaults[index]); 103 _cost_scan_hcc_seq->add(0.0); 104 _young_cards_per_entry_ratio_seq->add(young_cards_per_entry_ratio_defaults[index]); 105 _cost_per_entry_ms_seq->add(cost_per_entry_ms_defaults[index]); 106 _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]); 107 _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]); 108 _young_other_cost_per_region_ms_seq->add(young_other_cost_per_region_ms_defaults[index]); 109 _non_young_other_cost_per_region_ms_seq->add(non_young_other_cost_per_region_ms_defaults[index]); 110 111 // start conservatively (around 50ms is about right) 112 _concurrent_mark_remark_times_ms->add(0.05); 113 _concurrent_mark_cleanup_times_ms->add(0.20); 114 } 115 116 double G1Analytics::get_new_prediction(TruncatedSeq const* seq) const { 117 return _predictor->get_new_prediction(seq); 118 } 119 120 size_t G1Analytics::get_new_size_prediction(TruncatedSeq const* seq) const { 121 return (size_t)get_new_prediction(seq); 122 } 123 124 int G1Analytics::num_alloc_rate_ms() const { 125 return _alloc_rate_ms_seq->num(); 126 } 127 128 void G1Analytics::report_concurrent_mark_remark_times_ms(double ms) { 129 _concurrent_mark_remark_times_ms->add(ms); 130 } 131 132 void G1Analytics::report_alloc_rate_ms(double alloc_rate) { 133 _alloc_rate_ms_seq->add(alloc_rate); 134 } 135 136 void G1Analytics::compute_pause_time_ratio(double interval_ms, double pause_time_ms) { 137 _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum() / interval_ms; 138 if (_recent_avg_pause_time_ratio < 0.0 || 139 (_recent_avg_pause_time_ratio - 1.0 > 0.0)) { 140 // Clip ratio between 0.0 and 1.0, and continue. This will be fixed in 141 // CR 6902692 by redoing the manner in which the ratio is incrementally computed. 142 if (_recent_avg_pause_time_ratio < 0.0) { 143 _recent_avg_pause_time_ratio = 0.0; 144 } else { 145 assert(_recent_avg_pause_time_ratio - 1.0 > 0.0, "Ctl-point invariant"); 146 _recent_avg_pause_time_ratio = 1.0; 147 } 148 } 149 150 // Compute the ratio of just this last pause time to the entire time range stored 151 // in the vectors. Comparing this pause to the entire range, rather than only the 152 // most recent interval, has the effect of smoothing over a possible transient 'burst' 153 // of more frequent pauses that don't really reflect a change in heap occupancy. 154 // This reduces the likelihood of a needless heap expansion being triggered. 155 _last_pause_time_ratio = 156 (pause_time_ms * _recent_prev_end_times_for_all_gcs_sec->num()) / interval_ms; 157 } 158 159 void G1Analytics::report_cost_per_card_ms(double cost_per_card_ms) { 160 _cost_per_card_ms_seq->add(cost_per_card_ms); 161 } 162 163 void G1Analytics::report_cost_scan_hcc(double cost_scan_hcc) { 164 _cost_scan_hcc_seq->add(cost_scan_hcc); 165 } 166 167 void G1Analytics::report_cost_per_entry_ms(double cost_per_entry_ms, bool last_gc_was_young) { 168 if (last_gc_was_young) { 169 _cost_per_entry_ms_seq->add(cost_per_entry_ms); 170 } else { 171 _mixed_cost_per_entry_ms_seq->add(cost_per_entry_ms); 172 } 173 } 174 175 void G1Analytics::report_cards_per_entry_ratio(double cards_per_entry_ratio, bool last_gc_was_young) { 176 if (last_gc_was_young) { 177 _young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio); 178 } else { 179 _mixed_cards_per_entry_ratio_seq->add(cards_per_entry_ratio); 180 } 181 } 182 183 void G1Analytics::report_rs_length_diff(double rs_length_diff) { 184 _rs_length_diff_seq->add(rs_length_diff); 185 } 186 187 void G1Analytics::report_cost_per_byte_ms(double cost_per_byte_ms, bool in_marking_window) { 188 if (in_marking_window) { 189 _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms); 190 } else { 191 _cost_per_byte_ms_seq->add(cost_per_byte_ms); 192 } 193 } 194 195 void G1Analytics::report_young_other_cost_per_region_ms(double other_cost_per_region_ms) { 196 _young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms); 197 } 198 199 void G1Analytics::report_non_young_other_cost_per_region_ms(double other_cost_per_region_ms) { 200 _non_young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms); 201 } 202 203 void G1Analytics::report_constant_other_time_ms(double constant_other_time_ms) { 204 _constant_other_time_ms_seq->add(constant_other_time_ms); 205 } 206 207 void G1Analytics::report_pending_cards(double pending_cards) { 208 _pending_cards_seq->add(pending_cards); 209 } 210 211 void G1Analytics::report_rs_lengths(double rs_lengths) { 212 _rs_lengths_seq->add(rs_lengths); 213 } 214 215 size_t G1Analytics::predict_rs_length_diff() const { 216 return get_new_size_prediction(_rs_length_diff_seq); 217 } 218 219 double G1Analytics::predict_alloc_rate_ms() const { 220 return get_new_prediction(_alloc_rate_ms_seq); 221 } 222 223 double G1Analytics::predict_cost_per_card_ms() const { 224 return get_new_prediction(_cost_per_card_ms_seq); 225 } 226 227 double G1Analytics::predict_scan_hcc_ms() const { 228 return get_new_prediction(_cost_scan_hcc_seq); 229 } 230 231 double G1Analytics::predict_rs_update_time_ms(size_t pending_cards) const { 232 return pending_cards * predict_cost_per_card_ms() + predict_scan_hcc_ms(); 233 } 234 235 double G1Analytics::predict_young_cards_per_entry_ratio() const { 236 return get_new_prediction(_young_cards_per_entry_ratio_seq); 237 } 238 239 double G1Analytics::predict_mixed_cards_per_entry_ratio() const { 240 if (_mixed_cards_per_entry_ratio_seq->num() < 2) { 241 return predict_young_cards_per_entry_ratio(); 242 } else { 243 return get_new_prediction(_mixed_cards_per_entry_ratio_seq); 244 } 245 } 246 247 size_t G1Analytics::predict_card_num(size_t rs_length, bool gcs_are_young) const { 248 if (gcs_are_young) { 249 return (size_t) (rs_length * predict_young_cards_per_entry_ratio()); 250 } else { 251 return (size_t) (rs_length * predict_mixed_cards_per_entry_ratio()); 252 } 253 } 254 255 double G1Analytics::predict_rs_scan_time_ms(size_t card_num, bool gcs_are_young) const { 256 if (gcs_are_young) { 257 return card_num * get_new_prediction(_cost_per_entry_ms_seq); 258 } else { 259 return predict_mixed_rs_scan_time_ms(card_num); 260 } 261 } 262 263 double G1Analytics::predict_mixed_rs_scan_time_ms(size_t card_num) const { 264 if (_mixed_cost_per_entry_ms_seq->num() < 3) { 265 return card_num * get_new_prediction(_cost_per_entry_ms_seq); 266 } else { 267 return card_num * get_new_prediction(_mixed_cost_per_entry_ms_seq); 268 } 269 } 270 271 double G1Analytics::predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) const { 272 if (_cost_per_byte_ms_during_cm_seq->num() < 3) { 273 return (1.1 * bytes_to_copy) * get_new_prediction(_cost_per_byte_ms_seq); 274 } else { 275 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_during_cm_seq); 276 } 277 } 278 279 double G1Analytics::predict_object_copy_time_ms(size_t bytes_to_copy, bool during_concurrent_mark) const { 280 if (during_concurrent_mark) { 281 return predict_object_copy_time_ms_during_cm(bytes_to_copy); 282 } else { 283 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_seq); 284 } 285 } 286 287 double G1Analytics::predict_cost_per_byte_ms() const { 288 return get_new_prediction(_cost_per_byte_ms_seq); 289 } 290 291 double G1Analytics::predict_constant_other_time_ms() const { 292 return get_new_prediction(_constant_other_time_ms_seq); 293 } 294 295 double G1Analytics::predict_young_other_time_ms(size_t young_num) const { 296 return young_num * get_new_prediction(_young_other_cost_per_region_ms_seq); 297 } 298 299 double G1Analytics::predict_non_young_other_time_ms(size_t non_young_num) const { 300 return non_young_num * get_new_prediction(_non_young_other_cost_per_region_ms_seq); 301 } 302 303 double G1Analytics::predict_remark_time_ms() const { 304 return get_new_prediction(_concurrent_mark_remark_times_ms); 305 } 306 307 double G1Analytics::predict_cleanup_time_ms() const { 308 return get_new_prediction(_concurrent_mark_cleanup_times_ms); 309 } 310 311 size_t G1Analytics::predict_rs_lengths() const { 312 return get_new_size_prediction(_rs_lengths_seq); 313 } 314 315 size_t G1Analytics::predict_pending_cards() const { 316 return get_new_size_prediction(_pending_cards_seq); 317 } 318 319 double G1Analytics::oldest_known_gc_end_time_sec() const { 320 return _recent_prev_end_times_for_all_gcs_sec->oldest(); 321 } 322 323 double G1Analytics::last_known_gc_end_time_sec() const { 324 return _recent_prev_end_times_for_all_gcs_sec->last(); 325 } 326 327 void G1Analytics::update_recent_gc_times(double end_time_sec, 328 double pause_time_ms) { 329 _recent_gc_times_ms->add(pause_time_ms); 330 _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec); 331 _prev_collection_pause_end_ms = end_time_sec * 1000.0; 332 } 333 334 void G1Analytics::report_concurrent_mark_cleanup_times_ms(double ms) { 335 _concurrent_mark_cleanup_times_ms->add(ms); 336 }