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 }
--- EOF ---