src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp

Tue, 06 Apr 2010 10:59:45 -0400

author
tonyp
date
Tue, 06 Apr 2010 10:59:45 -0400
changeset 1794
23b1b27ac76c
parent 1791
56507bcd639e
child 1823
7666957bc44d
permissions
-rw-r--r--

6909756: G1: guarantee(G1CollectedHeap::heap()->mark_in_progress(),"Precondition.")
Summary: Make sure that two marking cycles do not overlap, i.e., a new one can only start after the concurrent marking thread finishes all its work. In the fix I piggy-back a couple of minor extra fixes: some general code reformatting for consistency (only around the code I modified), the removal of a field (G1CollectorPolicy::_should_initiate_conc_mark) which doesn't seem to be used at all (it's only set but never read), as well as moving the "is GC locker active" test earlier into the G1 pause / Full GC and using a more appropriate method for it.
Reviewed-by: johnc, jmasa, jcoomes, ysr

ysr@777 1 /*
xdono@1014 2 * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
ysr@777 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@777 4 *
ysr@777 5 * This code is free software; you can redistribute it and/or modify it
ysr@777 6 * under the terms of the GNU General Public License version 2 only, as
ysr@777 7 * published by the Free Software Foundation.
ysr@777 8 *
ysr@777 9 * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@777 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@777 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
ysr@777 12 * version 2 for more details (a copy is included in the LICENSE file that
ysr@777 13 * accompanied this code).
ysr@777 14 *
ysr@777 15 * You should have received a copy of the GNU General Public License version
ysr@777 16 * 2 along with this work; if not, write to the Free Software Foundation,
ysr@777 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@777 18 *
ysr@777 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
ysr@777 20 * CA 95054 USA or visit www.sun.com if you need additional information or
ysr@777 21 * have any questions.
ysr@777 22 *
ysr@777 23 */
ysr@777 24
ysr@777 25 #include "incls/_precompiled.incl"
ysr@777 26 #include "incls/_g1CollectorPolicy.cpp.incl"
ysr@777 27
ysr@777 28 #define PREDICTIONS_VERBOSE 0
ysr@777 29
ysr@777 30 // <NEW PREDICTION>
ysr@777 31
ysr@777 32 // Different defaults for different number of GC threads
ysr@777 33 // They were chosen by running GCOld and SPECjbb on debris with different
ysr@777 34 // numbers of GC threads and choosing them based on the results
ysr@777 35
ysr@777 36 // all the same
ysr@777 37 static double rs_length_diff_defaults[] = {
ysr@777 38 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
ysr@777 39 };
ysr@777 40
ysr@777 41 static double cost_per_card_ms_defaults[] = {
ysr@777 42 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015
ysr@777 43 };
ysr@777 44
ysr@777 45 static double cost_per_scan_only_region_ms_defaults[] = {
ysr@777 46 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
ysr@777 47 };
ysr@777 48
ysr@777 49 // all the same
ysr@777 50 static double fully_young_cards_per_entry_ratio_defaults[] = {
ysr@777 51 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
ysr@777 52 };
ysr@777 53
ysr@777 54 static double cost_per_entry_ms_defaults[] = {
ysr@777 55 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005
ysr@777 56 };
ysr@777 57
ysr@777 58 static double cost_per_byte_ms_defaults[] = {
ysr@777 59 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009
ysr@777 60 };
ysr@777 61
ysr@777 62 // these should be pretty consistent
ysr@777 63 static double constant_other_time_ms_defaults[] = {
ysr@777 64 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0
ysr@777 65 };
ysr@777 66
ysr@777 67
ysr@777 68 static double young_other_cost_per_region_ms_defaults[] = {
ysr@777 69 0.3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1
ysr@777 70 };
ysr@777 71
ysr@777 72 static double non_young_other_cost_per_region_ms_defaults[] = {
ysr@777 73 1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30
ysr@777 74 };
ysr@777 75
ysr@777 76 // </NEW PREDICTION>
ysr@777 77
ysr@777 78 G1CollectorPolicy::G1CollectorPolicy() :
ysr@777 79 _parallel_gc_threads((ParallelGCThreads > 0) ? ParallelGCThreads : 1),
ysr@777 80 _n_pauses(0),
ysr@777 81 _recent_CH_strong_roots_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 82 _recent_G1_strong_roots_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 83 _recent_evac_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 84 _recent_pause_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 85 _recent_rs_sizes(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 86 _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 87 _all_pause_times_ms(new NumberSeq()),
ysr@777 88 _stop_world_start(0.0),
ysr@777 89 _all_stop_world_times_ms(new NumberSeq()),
ysr@777 90 _all_yield_times_ms(new NumberSeq()),
ysr@777 91
ysr@777 92 _all_mod_union_times_ms(new NumberSeq()),
ysr@777 93
apetrusenko@1112 94 _summary(new Summary()),
apetrusenko@1112 95 _abandoned_summary(new AbandonedSummary()),
ysr@777 96
johnc@1325 97 #ifndef PRODUCT
ysr@777 98 _cur_clear_ct_time_ms(0.0),
johnc@1325 99 _min_clear_cc_time_ms(-1.0),
johnc@1325 100 _max_clear_cc_time_ms(-1.0),
johnc@1325 101 _cur_clear_cc_time_ms(0.0),
johnc@1325 102 _cum_clear_cc_time_ms(0.0),
johnc@1325 103 _num_cc_clears(0L),
johnc@1325 104 #endif
ysr@777 105
ysr@777 106 _region_num_young(0),
ysr@777 107 _region_num_tenured(0),
ysr@777 108 _prev_region_num_young(0),
ysr@777 109 _prev_region_num_tenured(0),
ysr@777 110
ysr@777 111 _aux_num(10),
ysr@777 112 _all_aux_times_ms(new NumberSeq[_aux_num]),
ysr@777 113 _cur_aux_start_times_ms(new double[_aux_num]),
ysr@777 114 _cur_aux_times_ms(new double[_aux_num]),
ysr@777 115 _cur_aux_times_set(new bool[_aux_num]),
ysr@777 116
ysr@777 117 _concurrent_mark_init_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 118 _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 119 _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 120
ysr@777 121 // <NEW PREDICTION>
ysr@777 122
ysr@777 123 _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 124 _prev_collection_pause_end_ms(0.0),
ysr@777 125 _pending_card_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 126 _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 127 _cost_per_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 128 _cost_per_scan_only_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 129 _fully_young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 130 _partially_young_cards_per_entry_ratio_seq(
ysr@777 131 new TruncatedSeq(TruncatedSeqLength)),
ysr@777 132 _cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 133 _partially_young_cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 134 _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 135 _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 136 _cost_per_scan_only_region_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 137 _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 138 _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 139 _non_young_other_cost_per_region_ms_seq(
ysr@777 140 new TruncatedSeq(TruncatedSeqLength)),
ysr@777 141
ysr@777 142 _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 143 _scanned_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 144 _rs_lengths_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 145
johnc@1186 146 _pause_time_target_ms((double) MaxGCPauseMillis),
ysr@777 147
ysr@777 148 // </NEW PREDICTION>
ysr@777 149
ysr@777 150 _in_young_gc_mode(false),
ysr@777 151 _full_young_gcs(true),
ysr@777 152 _full_young_pause_num(0),
ysr@777 153 _partial_young_pause_num(0),
ysr@777 154
ysr@777 155 _during_marking(false),
ysr@777 156 _in_marking_window(false),
ysr@777 157 _in_marking_window_im(false),
ysr@777 158
ysr@777 159 _known_garbage_ratio(0.0),
ysr@777 160 _known_garbage_bytes(0),
ysr@777 161
ysr@777 162 _young_gc_eff_seq(new TruncatedSeq(TruncatedSeqLength)),
ysr@777 163 _target_pause_time_ms(-1.0),
ysr@777 164
ysr@777 165 _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 166
ysr@777 167 _recent_CS_bytes_used_before(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 168 _recent_CS_bytes_surviving(new TruncatedSeq(NumPrevPausesForHeuristics)),
ysr@777 169
ysr@777 170 _recent_avg_pause_time_ratio(0.0),
ysr@777 171 _num_markings(0),
ysr@777 172 _n_marks(0),
ysr@777 173 _n_pauses_at_mark_end(0),
ysr@777 174
ysr@777 175 _all_full_gc_times_ms(new NumberSeq()),
ysr@777 176
ysr@777 177 // G1PausesBtwnConcMark defaults to -1
ysr@777 178 // so the hack is to do the cast QQQ FIXME
ysr@777 179 _pauses_btwn_concurrent_mark((size_t)G1PausesBtwnConcMark),
ysr@777 180 _n_marks_since_last_pause(0),
tonyp@1794 181 _initiate_conc_mark_if_possible(false),
tonyp@1794 182 _during_initial_mark_pause(false),
ysr@777 183 _should_revert_to_full_young_gcs(false),
ysr@777 184 _last_full_young_gc(false),
ysr@777 185
ysr@777 186 _prev_collection_pause_used_at_end_bytes(0),
ysr@777 187
ysr@777 188 _collection_set(NULL),
ysr@777 189 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
ysr@777 190 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
ysr@777 191 #endif // _MSC_VER
ysr@777 192
ysr@777 193 _short_lived_surv_rate_group(new SurvRateGroup(this, "Short Lived",
ysr@777 194 G1YoungSurvRateNumRegionsSummary)),
ysr@777 195 _survivor_surv_rate_group(new SurvRateGroup(this, "Survivor",
apetrusenko@980 196 G1YoungSurvRateNumRegionsSummary)),
ysr@777 197 // add here any more surv rate groups
apetrusenko@980 198 _recorded_survivor_regions(0),
apetrusenko@980 199 _recorded_survivor_head(NULL),
apetrusenko@980 200 _recorded_survivor_tail(NULL),
tonyp@1791 201 _survivors_age_table(true),
tonyp@1791 202
tonyp@1791 203 _gc_overhead_perc(0.0)
apetrusenko@980 204
ysr@777 205 {
tonyp@1377 206 // Set up the region size and associated fields. Given that the
tonyp@1377 207 // policy is created before the heap, we have to set this up here,
tonyp@1377 208 // so it's done as soon as possible.
tonyp@1377 209 HeapRegion::setup_heap_region_size(Arguments::min_heap_size());
iveresov@1696 210 HeapRegionRemSet::setup_remset_size();
tonyp@1377 211
ysr@777 212 _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime());
ysr@777 213 _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0;
ysr@777 214
ysr@777 215 _par_last_ext_root_scan_times_ms = new double[_parallel_gc_threads];
ysr@777 216 _par_last_mark_stack_scan_times_ms = new double[_parallel_gc_threads];
ysr@777 217 _par_last_scan_only_times_ms = new double[_parallel_gc_threads];
ysr@777 218 _par_last_scan_only_regions_scanned = new double[_parallel_gc_threads];
ysr@777 219
ysr@777 220 _par_last_update_rs_start_times_ms = new double[_parallel_gc_threads];
ysr@777 221 _par_last_update_rs_times_ms = new double[_parallel_gc_threads];
ysr@777 222 _par_last_update_rs_processed_buffers = new double[_parallel_gc_threads];
ysr@777 223
ysr@777 224 _par_last_scan_rs_start_times_ms = new double[_parallel_gc_threads];
ysr@777 225 _par_last_scan_rs_times_ms = new double[_parallel_gc_threads];
ysr@777 226 _par_last_scan_new_refs_times_ms = new double[_parallel_gc_threads];
ysr@777 227
ysr@777 228 _par_last_obj_copy_times_ms = new double[_parallel_gc_threads];
ysr@777 229
ysr@777 230 _par_last_termination_times_ms = new double[_parallel_gc_threads];
ysr@777 231
ysr@777 232 // start conservatively
johnc@1186 233 _expensive_region_limit_ms = 0.5 * (double) MaxGCPauseMillis;
ysr@777 234
ysr@777 235 // <NEW PREDICTION>
ysr@777 236
ysr@777 237 int index;
ysr@777 238 if (ParallelGCThreads == 0)
ysr@777 239 index = 0;
ysr@777 240 else if (ParallelGCThreads > 8)
ysr@777 241 index = 7;
ysr@777 242 else
ysr@777 243 index = ParallelGCThreads - 1;
ysr@777 244
ysr@777 245 _pending_card_diff_seq->add(0.0);
ysr@777 246 _rs_length_diff_seq->add(rs_length_diff_defaults[index]);
ysr@777 247 _cost_per_card_ms_seq->add(cost_per_card_ms_defaults[index]);
ysr@777 248 _cost_per_scan_only_region_ms_seq->add(
ysr@777 249 cost_per_scan_only_region_ms_defaults[index]);
ysr@777 250 _fully_young_cards_per_entry_ratio_seq->add(
ysr@777 251 fully_young_cards_per_entry_ratio_defaults[index]);
ysr@777 252 _cost_per_entry_ms_seq->add(cost_per_entry_ms_defaults[index]);
ysr@777 253 _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]);
ysr@777 254 _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]);
ysr@777 255 _young_other_cost_per_region_ms_seq->add(
ysr@777 256 young_other_cost_per_region_ms_defaults[index]);
ysr@777 257 _non_young_other_cost_per_region_ms_seq->add(
ysr@777 258 non_young_other_cost_per_region_ms_defaults[index]);
ysr@777 259
ysr@777 260 // </NEW PREDICTION>
ysr@777 261
johnc@1186 262 double time_slice = (double) GCPauseIntervalMillis / 1000.0;
johnc@1186 263 double max_gc_time = (double) MaxGCPauseMillis / 1000.0;
ysr@777 264 guarantee(max_gc_time < time_slice,
ysr@777 265 "Max GC time should not be greater than the time slice");
ysr@777 266 _mmu_tracker = new G1MMUTrackerQueue(time_slice, max_gc_time);
johnc@1186 267 _sigma = (double) G1ConfidencePercent / 100.0;
ysr@777 268
ysr@777 269 // start conservatively (around 50ms is about right)
ysr@777 270 _concurrent_mark_init_times_ms->add(0.05);
ysr@777 271 _concurrent_mark_remark_times_ms->add(0.05);
ysr@777 272 _concurrent_mark_cleanup_times_ms->add(0.20);
ysr@777 273 _tenuring_threshold = MaxTenuringThreshold;
ysr@777 274
tonyp@1717 275 // if G1FixedSurvivorSpaceSize is 0 which means the size is not
tonyp@1717 276 // fixed, then _max_survivor_regions will be calculated at
tonyp@1717 277 // calculate_young_list_target_config during initialization
tonyp@1717 278 _max_survivor_regions = G1FixedSurvivorSpaceSize / HeapRegion::GrainBytes;
apetrusenko@980 279
tonyp@1791 280 assert(GCTimeRatio > 0,
tonyp@1791 281 "we should have set it to a default value set_g1_gc_flags() "
tonyp@1791 282 "if a user set it to 0");
tonyp@1791 283 _gc_overhead_perc = 100.0 * (1.0 / (1.0 + GCTimeRatio));
tonyp@1791 284
ysr@777 285 initialize_all();
ysr@777 286 }
ysr@777 287
ysr@777 288 // Increment "i", mod "len"
ysr@777 289 static void inc_mod(int& i, int len) {
ysr@777 290 i++; if (i == len) i = 0;
ysr@777 291 }
ysr@777 292
ysr@777 293 void G1CollectorPolicy::initialize_flags() {
ysr@777 294 set_min_alignment(HeapRegion::GrainBytes);
ysr@777 295 set_max_alignment(GenRemSet::max_alignment_constraint(rem_set_name()));
apetrusenko@982 296 if (SurvivorRatio < 1) {
apetrusenko@982 297 vm_exit_during_initialization("Invalid survivor ratio specified");
apetrusenko@982 298 }
ysr@777 299 CollectorPolicy::initialize_flags();
ysr@777 300 }
ysr@777 301
tonyp@1720 302 // The easiest way to deal with the parsing of the NewSize /
tonyp@1720 303 // MaxNewSize / etc. parameteres is to re-use the code in the
tonyp@1720 304 // TwoGenerationCollectorPolicy class. This is similar to what
tonyp@1720 305 // ParallelScavenge does with its GenerationSizer class (see
tonyp@1720 306 // ParallelScavengeHeap::initialize()). We might change this in the
tonyp@1720 307 // future, but it's a good start.
tonyp@1720 308 class G1YoungGenSizer : public TwoGenerationCollectorPolicy {
tonyp@1720 309 size_t size_to_region_num(size_t byte_size) {
tonyp@1720 310 return MAX2((size_t) 1, byte_size / HeapRegion::GrainBytes);
tonyp@1720 311 }
tonyp@1720 312
tonyp@1720 313 public:
tonyp@1720 314 G1YoungGenSizer() {
tonyp@1720 315 initialize_flags();
tonyp@1720 316 initialize_size_info();
tonyp@1720 317 }
tonyp@1720 318
tonyp@1720 319 size_t min_young_region_num() {
tonyp@1720 320 return size_to_region_num(_min_gen0_size);
tonyp@1720 321 }
tonyp@1720 322 size_t initial_young_region_num() {
tonyp@1720 323 return size_to_region_num(_initial_gen0_size);
tonyp@1720 324 }
tonyp@1720 325 size_t max_young_region_num() {
tonyp@1720 326 return size_to_region_num(_max_gen0_size);
tonyp@1720 327 }
tonyp@1720 328 };
tonyp@1720 329
ysr@777 330 void G1CollectorPolicy::init() {
ysr@777 331 // Set aside an initial future to_space.
ysr@777 332 _g1 = G1CollectedHeap::heap();
ysr@777 333
ysr@777 334 assert(Heap_lock->owned_by_self(), "Locking discipline.");
ysr@777 335
apetrusenko@980 336 initialize_gc_policy_counters();
apetrusenko@980 337
ysr@777 338 if (G1Gen) {
ysr@777 339 _in_young_gc_mode = true;
ysr@777 340
tonyp@1720 341 G1YoungGenSizer sizer;
tonyp@1720 342 size_t initial_region_num = sizer.initial_young_region_num();
tonyp@1720 343
tonyp@1720 344 if (UseAdaptiveSizePolicy) {
ysr@777 345 set_adaptive_young_list_length(true);
ysr@777 346 _young_list_fixed_length = 0;
ysr@777 347 } else {
ysr@777 348 set_adaptive_young_list_length(false);
tonyp@1720 349 _young_list_fixed_length = initial_region_num;
ysr@777 350 }
ysr@777 351 _free_regions_at_end_of_collection = _g1->free_regions();
ysr@777 352 _scan_only_regions_at_end_of_collection = 0;
ysr@777 353 calculate_young_list_min_length();
ysr@777 354 guarantee( _young_list_min_length == 0, "invariant, not enough info" );
ysr@777 355 calculate_young_list_target_config();
ysr@777 356 } else {
ysr@777 357 _young_list_fixed_length = 0;
ysr@777 358 _in_young_gc_mode = false;
ysr@777 359 }
ysr@777 360 }
ysr@777 361
apetrusenko@980 362 // Create the jstat counters for the policy.
apetrusenko@980 363 void G1CollectorPolicy::initialize_gc_policy_counters()
apetrusenko@980 364 {
apetrusenko@980 365 _gc_policy_counters = new GCPolicyCounters("GarbageFirst", 1, 2 + G1Gen);
apetrusenko@980 366 }
apetrusenko@980 367
ysr@777 368 void G1CollectorPolicy::calculate_young_list_min_length() {
ysr@777 369 _young_list_min_length = 0;
ysr@777 370
ysr@777 371 if (!adaptive_young_list_length())
ysr@777 372 return;
ysr@777 373
ysr@777 374 if (_alloc_rate_ms_seq->num() > 3) {
ysr@777 375 double now_sec = os::elapsedTime();
ysr@777 376 double when_ms = _mmu_tracker->when_max_gc_sec(now_sec) * 1000.0;
ysr@777 377 double alloc_rate_ms = predict_alloc_rate_ms();
ysr@777 378 int min_regions = (int) ceil(alloc_rate_ms * when_ms);
ysr@777 379 int current_region_num = (int) _g1->young_list_length();
ysr@777 380 _young_list_min_length = min_regions + current_region_num;
ysr@777 381 }
ysr@777 382 }
ysr@777 383
ysr@777 384 void G1CollectorPolicy::calculate_young_list_target_config() {
ysr@777 385 if (adaptive_young_list_length()) {
ysr@777 386 size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
ysr@777 387 calculate_young_list_target_config(rs_lengths);
ysr@777 388 } else {
ysr@777 389 if (full_young_gcs())
ysr@777 390 _young_list_target_length = _young_list_fixed_length;
ysr@777 391 else
ysr@777 392 _young_list_target_length = _young_list_fixed_length / 2;
ysr@777 393 _young_list_target_length = MAX2(_young_list_target_length, (size_t)1);
ysr@777 394 size_t so_length = calculate_optimal_so_length(_young_list_target_length);
ysr@777 395 guarantee( so_length < _young_list_target_length, "invariant" );
ysr@777 396 _young_list_so_prefix_length = so_length;
ysr@777 397 }
apetrusenko@980 398 calculate_survivors_policy();
ysr@777 399 }
ysr@777 400
ysr@777 401 // This method calculate the optimal scan-only set for a fixed young
ysr@777 402 // gen size. I couldn't work out how to reuse the more elaborate one,
ysr@777 403 // i.e. calculate_young_list_target_config(rs_length), as the loops are
ysr@777 404 // fundamentally different (the other one finds a config for different
ysr@777 405 // S-O lengths, whereas here we need to do the opposite).
ysr@777 406 size_t G1CollectorPolicy::calculate_optimal_so_length(
ysr@777 407 size_t young_list_length) {
ysr@777 408 if (!G1UseScanOnlyPrefix)
ysr@777 409 return 0;
ysr@777 410
ysr@777 411 if (_all_pause_times_ms->num() < 3) {
ysr@777 412 // we won't use a scan-only set at the beginning to allow the rest
ysr@777 413 // of the predictors to warm up
ysr@777 414 return 0;
ysr@777 415 }
ysr@777 416
ysr@777 417 if (_cost_per_scan_only_region_ms_seq->num() < 3) {
ysr@777 418 // then, we'll only set the S-O set to 1 for a little bit of time,
ysr@777 419 // to get enough information on the scanning cost
ysr@777 420 return 1;
ysr@777 421 }
ysr@777 422
ysr@777 423 size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
ysr@777 424 size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
ysr@777 425 size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
ysr@777 426 size_t scanned_cards;
ysr@777 427 if (full_young_gcs())
ysr@777 428 scanned_cards = predict_young_card_num(adj_rs_lengths);
ysr@777 429 else
ysr@777 430 scanned_cards = predict_non_young_card_num(adj_rs_lengths);
ysr@777 431 double base_time_ms = predict_base_elapsed_time_ms(pending_cards,
ysr@777 432 scanned_cards);
ysr@777 433
ysr@777 434 size_t so_length = 0;
ysr@777 435 double max_gc_eff = 0.0;
ysr@777 436 for (size_t i = 0; i < young_list_length; ++i) {
ysr@777 437 double gc_eff = 0.0;
ysr@777 438 double pause_time_ms = 0.0;
ysr@777 439 predict_gc_eff(young_list_length, i, base_time_ms,
ysr@777 440 &gc_eff, &pause_time_ms);
ysr@777 441 if (gc_eff > max_gc_eff) {
ysr@777 442 max_gc_eff = gc_eff;
ysr@777 443 so_length = i;
ysr@777 444 }
ysr@777 445 }
ysr@777 446
ysr@777 447 // set it to 95% of the optimal to make sure we sample the "area"
ysr@777 448 // around the optimal length to get up-to-date survival rate data
ysr@777 449 return so_length * 950 / 1000;
ysr@777 450 }
ysr@777 451
ysr@777 452 // This is a really cool piece of code! It finds the best
ysr@777 453 // target configuration (young length / scan-only prefix length) so
ysr@777 454 // that GC efficiency is maximized and that we also meet a pause
ysr@777 455 // time. It's a triple nested loop. These loops are explained below
ysr@777 456 // from the inside-out :-)
ysr@777 457 //
ysr@777 458 // (a) The innermost loop will try to find the optimal young length
ysr@777 459 // for a fixed S-O length. It uses a binary search to speed up the
ysr@777 460 // process. We assume that, for a fixed S-O length, as we add more
ysr@777 461 // young regions to the CSet, the GC efficiency will only go up (I'll
ysr@777 462 // skip the proof). So, using a binary search to optimize this process
ysr@777 463 // makes perfect sense.
ysr@777 464 //
ysr@777 465 // (b) The middle loop will fix the S-O length before calling the
ysr@777 466 // innermost one. It will vary it between two parameters, increasing
ysr@777 467 // it by a given increment.
ysr@777 468 //
ysr@777 469 // (c) The outermost loop will call the middle loop three times.
ysr@777 470 // (1) The first time it will explore all possible S-O length values
ysr@777 471 // from 0 to as large as it can get, using a coarse increment (to
ysr@777 472 // quickly "home in" to where the optimal seems to be).
ysr@777 473 // (2) The second time it will explore the values around the optimal
ysr@777 474 // that was found by the first iteration using a fine increment.
ysr@777 475 // (3) Once the optimal config has been determined by the second
ysr@777 476 // iteration, we'll redo the calculation, but setting the S-O length
ysr@777 477 // to 95% of the optimal to make sure we sample the "area"
ysr@777 478 // around the optimal length to get up-to-date survival rate data
ysr@777 479 //
ysr@777 480 // Termination conditions for the iterations are several: the pause
ysr@777 481 // time is over the limit, we do not have enough to-space, etc.
ysr@777 482
ysr@777 483 void G1CollectorPolicy::calculate_young_list_target_config(size_t rs_lengths) {
ysr@777 484 guarantee( adaptive_young_list_length(), "pre-condition" );
ysr@777 485
ysr@777 486 double start_time_sec = os::elapsedTime();
tonyp@1717 487 size_t min_reserve_perc = MAX2((size_t)2, (size_t)G1ReservePercent);
ysr@777 488 min_reserve_perc = MIN2((size_t) 50, min_reserve_perc);
ysr@777 489 size_t reserve_regions =
ysr@777 490 (size_t) ((double) min_reserve_perc * (double) _g1->n_regions() / 100.0);
ysr@777 491
ysr@777 492 if (full_young_gcs() && _free_regions_at_end_of_collection > 0) {
ysr@777 493 // we are in fully-young mode and there are free regions in the heap
ysr@777 494
apetrusenko@980 495 double survivor_regions_evac_time =
apetrusenko@980 496 predict_survivor_regions_evac_time();
apetrusenko@980 497
ysr@777 498 size_t min_so_length = 0;
ysr@777 499 size_t max_so_length = 0;
ysr@777 500
ysr@777 501 if (G1UseScanOnlyPrefix) {
ysr@777 502 if (_all_pause_times_ms->num() < 3) {
ysr@777 503 // we won't use a scan-only set at the beginning to allow the rest
ysr@777 504 // of the predictors to warm up
ysr@777 505 min_so_length = 0;
ysr@777 506 max_so_length = 0;
ysr@777 507 } else if (_cost_per_scan_only_region_ms_seq->num() < 3) {
ysr@777 508 // then, we'll only set the S-O set to 1 for a little bit of time,
ysr@777 509 // to get enough information on the scanning cost
ysr@777 510 min_so_length = 1;
ysr@777 511 max_so_length = 1;
ysr@777 512 } else if (_in_marking_window || _last_full_young_gc) {
ysr@777 513 // no S-O prefix during a marking phase either, as at the end
ysr@777 514 // of the marking phase we'll have to use a very small young
ysr@777 515 // length target to fill up the rest of the CSet with
ysr@777 516 // non-young regions and, if we have lots of scan-only regions
ysr@777 517 // left-over, we will not be able to add any more non-young
ysr@777 518 // regions.
ysr@777 519 min_so_length = 0;
ysr@777 520 max_so_length = 0;
ysr@777 521 } else {
ysr@777 522 // this is the common case; we'll never reach the maximum, we
ysr@777 523 // one of the end conditions will fire well before that
ysr@777 524 // (hopefully!)
ysr@777 525 min_so_length = 0;
ysr@777 526 max_so_length = _free_regions_at_end_of_collection - 1;
ysr@777 527 }
ysr@777 528 } else {
ysr@777 529 // no S-O prefix, as the switch is not set, but we still need to
ysr@777 530 // do one iteration to calculate the best young target that
ysr@777 531 // meets the pause time; this way we reuse the same code instead
ysr@777 532 // of replicating it
ysr@777 533 min_so_length = 0;
ysr@777 534 max_so_length = 0;
ysr@777 535 }
ysr@777 536
ysr@777 537 double target_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
ysr@777 538 size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
ysr@777 539 size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
ysr@777 540 size_t scanned_cards;
ysr@777 541 if (full_young_gcs())
ysr@777 542 scanned_cards = predict_young_card_num(adj_rs_lengths);
ysr@777 543 else
ysr@777 544 scanned_cards = predict_non_young_card_num(adj_rs_lengths);
ysr@777 545 // calculate this once, so that we don't have to recalculate it in
ysr@777 546 // the innermost loop
apetrusenko@980 547 double base_time_ms = predict_base_elapsed_time_ms(pending_cards, scanned_cards)
apetrusenko@980 548 + survivor_regions_evac_time;
ysr@777 549 // the result
ysr@777 550 size_t final_young_length = 0;
ysr@777 551 size_t final_so_length = 0;
ysr@777 552 double final_gc_eff = 0.0;
ysr@777 553 // we'll also keep track of how many times we go into the inner loop
ysr@777 554 // this is for profiling reasons
ysr@777 555 size_t calculations = 0;
ysr@777 556
ysr@777 557 // this determines which of the three iterations the outer loop is in
ysr@777 558 typedef enum {
ysr@777 559 pass_type_coarse,
ysr@777 560 pass_type_fine,
ysr@777 561 pass_type_final
ysr@777 562 } pass_type_t;
ysr@777 563
ysr@777 564 // range of the outer loop's iteration
ysr@777 565 size_t from_so_length = min_so_length;
ysr@777 566 size_t to_so_length = max_so_length;
ysr@777 567 guarantee( from_so_length <= to_so_length, "invariant" );
ysr@777 568
ysr@777 569 // this will keep the S-O length that's found by the second
ysr@777 570 // iteration of the outer loop; we'll keep it just in case the third
ysr@777 571 // iteration fails to find something
ysr@777 572 size_t fine_so_length = 0;
ysr@777 573
ysr@777 574 // the increment step for the coarse (first) iteration
ysr@777 575 size_t so_coarse_increments = 5;
ysr@777 576
ysr@777 577 // the common case, we'll start with the coarse iteration
ysr@777 578 pass_type_t pass = pass_type_coarse;
ysr@777 579 size_t so_length_incr = so_coarse_increments;
ysr@777 580
ysr@777 581 if (from_so_length == to_so_length) {
ysr@777 582 // not point in doing the coarse iteration, we'll go directly into
ysr@777 583 // the fine one (we essentially trying to find the optimal young
ysr@777 584 // length for a fixed S-O length).
ysr@777 585 so_length_incr = 1;
ysr@777 586 pass = pass_type_final;
ysr@777 587 } else if (to_so_length - from_so_length < 3 * so_coarse_increments) {
ysr@777 588 // again, the range is too short so no point in foind the coarse
ysr@777 589 // iteration either
ysr@777 590 so_length_incr = 1;
ysr@777 591 pass = pass_type_fine;
ysr@777 592 }
ysr@777 593
ysr@777 594 bool done = false;
ysr@777 595 // this is the outermost loop
ysr@777 596 while (!done) {
apetrusenko@980 597 #ifdef TRACE_CALC_YOUNG_CONFIG
ysr@777 598 // leave this in for debugging, just in case
ysr@777 599 gclog_or_tty->print_cr("searching between " SIZE_FORMAT " and " SIZE_FORMAT
ysr@777 600 ", incr " SIZE_FORMAT ", pass %s",
ysr@777 601 from_so_length, to_so_length, so_length_incr,
ysr@777 602 (pass == pass_type_coarse) ? "coarse" :
ysr@777 603 (pass == pass_type_fine) ? "fine" : "final");
apetrusenko@980 604 #endif // TRACE_CALC_YOUNG_CONFIG
ysr@777 605
ysr@777 606 size_t so_length = from_so_length;
ysr@777 607 size_t init_free_regions =
ysr@777 608 MAX2((size_t)0,
ysr@777 609 _free_regions_at_end_of_collection +
ysr@777 610 _scan_only_regions_at_end_of_collection - reserve_regions);
ysr@777 611
ysr@777 612 // this determines whether a configuration was found
ysr@777 613 bool gc_eff_set = false;
ysr@777 614 // this is the middle loop
ysr@777 615 while (so_length <= to_so_length) {
ysr@777 616 // base time, which excludes region-related time; again we
ysr@777 617 // calculate it once to avoid recalculating it in the
ysr@777 618 // innermost loop
ysr@777 619 double base_time_with_so_ms =
ysr@777 620 base_time_ms + predict_scan_only_time_ms(so_length);
ysr@777 621 // it's already over the pause target, go around
ysr@777 622 if (base_time_with_so_ms > target_pause_time_ms)
ysr@777 623 break;
ysr@777 624
ysr@777 625 size_t starting_young_length = so_length+1;
ysr@777 626
ysr@777 627 // we make sure that the short young length that makes sense
ysr@777 628 // (one more than the S-O length) is feasible
ysr@777 629 size_t min_young_length = starting_young_length;
ysr@777 630 double min_gc_eff;
ysr@777 631 bool min_ok;
ysr@777 632 ++calculations;
ysr@777 633 min_ok = predict_gc_eff(min_young_length, so_length,
ysr@777 634 base_time_with_so_ms,
ysr@777 635 init_free_regions, target_pause_time_ms,
ysr@777 636 &min_gc_eff);
ysr@777 637
ysr@777 638 if (min_ok) {
ysr@777 639 // the shortest young length is indeed feasible; we'll know
ysr@777 640 // set up the max young length and we'll do a binary search
ysr@777 641 // between min_young_length and max_young_length
ysr@777 642 size_t max_young_length = _free_regions_at_end_of_collection - 1;
ysr@777 643 double max_gc_eff = 0.0;
ysr@777 644 bool max_ok = false;
ysr@777 645
ysr@777 646 // the innermost loop! (finally!)
ysr@777 647 while (max_young_length > min_young_length) {
ysr@777 648 // we'll make sure that min_young_length is always at a
ysr@777 649 // feasible config
ysr@777 650 guarantee( min_ok, "invariant" );
ysr@777 651
ysr@777 652 ++calculations;
ysr@777 653 max_ok = predict_gc_eff(max_young_length, so_length,
ysr@777 654 base_time_with_so_ms,
ysr@777 655 init_free_regions, target_pause_time_ms,
ysr@777 656 &max_gc_eff);
ysr@777 657
ysr@777 658 size_t diff = (max_young_length - min_young_length) / 2;
ysr@777 659 if (max_ok) {
ysr@777 660 min_young_length = max_young_length;
ysr@777 661 min_gc_eff = max_gc_eff;
ysr@777 662 min_ok = true;
ysr@777 663 }
ysr@777 664 max_young_length = min_young_length + diff;
ysr@777 665 }
ysr@777 666
ysr@777 667 // the innermost loop found a config
ysr@777 668 guarantee( min_ok, "invariant" );
ysr@777 669 if (min_gc_eff > final_gc_eff) {
ysr@777 670 // it's the best config so far, so we'll keep it
ysr@777 671 final_gc_eff = min_gc_eff;
ysr@777 672 final_young_length = min_young_length;
ysr@777 673 final_so_length = so_length;
ysr@777 674 gc_eff_set = true;
ysr@777 675 }
ysr@777 676 }
ysr@777 677
ysr@777 678 // incremental the fixed S-O length and go around
ysr@777 679 so_length += so_length_incr;
ysr@777 680 }
ysr@777 681
ysr@777 682 // this is the end of the outermost loop and we need to decide
ysr@777 683 // what to do during the next iteration
ysr@777 684 if (pass == pass_type_coarse) {
ysr@777 685 // we just did the coarse pass (first iteration)
ysr@777 686
ysr@777 687 if (!gc_eff_set)
ysr@777 688 // we didn't find a feasible config so we'll just bail out; of
ysr@777 689 // course, it might be the case that we missed it; but I'd say
ysr@777 690 // it's a bit unlikely
ysr@777 691 done = true;
ysr@777 692 else {
ysr@777 693 // We did find a feasible config with optimal GC eff during
ysr@777 694 // the first pass. So the second pass we'll only consider the
ysr@777 695 // S-O lengths around that config with a fine increment.
ysr@777 696
ysr@777 697 guarantee( so_length_incr == so_coarse_increments, "invariant" );
ysr@777 698 guarantee( final_so_length >= min_so_length, "invariant" );
ysr@777 699
apetrusenko@980 700 #ifdef TRACE_CALC_YOUNG_CONFIG
ysr@777 701 // leave this in for debugging, just in case
ysr@777 702 gclog_or_tty->print_cr(" coarse pass: SO length " SIZE_FORMAT,
ysr@777 703 final_so_length);
apetrusenko@980 704 #endif // TRACE_CALC_YOUNG_CONFIG
ysr@777 705
ysr@777 706 from_so_length =
ysr@777 707 (final_so_length - min_so_length > so_coarse_increments) ?
ysr@777 708 final_so_length - so_coarse_increments + 1 : min_so_length;
ysr@777 709 to_so_length =
ysr@777 710 (max_so_length - final_so_length > so_coarse_increments) ?
ysr@777 711 final_so_length + so_coarse_increments - 1 : max_so_length;
ysr@777 712
ysr@777 713 pass = pass_type_fine;
ysr@777 714 so_length_incr = 1;
ysr@777 715 }
ysr@777 716 } else if (pass == pass_type_fine) {
ysr@777 717 // we just finished the second pass
ysr@777 718
ysr@777 719 if (!gc_eff_set) {
ysr@777 720 // we didn't find a feasible config (yes, it's possible;
ysr@777 721 // notice that, sometimes, we go directly into the fine
ysr@777 722 // iteration and skip the coarse one) so we bail out
ysr@777 723 done = true;
ysr@777 724 } else {
ysr@777 725 // We did find a feasible config with optimal GC eff
ysr@777 726 guarantee( so_length_incr == 1, "invariant" );
ysr@777 727
ysr@777 728 if (final_so_length == 0) {
ysr@777 729 // The config is of an empty S-O set, so we'll just bail out
ysr@777 730 done = true;
ysr@777 731 } else {
ysr@777 732 // we'll go around once more, setting the S-O length to 95%
ysr@777 733 // of the optimal
ysr@777 734 size_t new_so_length = 950 * final_so_length / 1000;
ysr@777 735
apetrusenko@980 736 #ifdef TRACE_CALC_YOUNG_CONFIG
ysr@777 737 // leave this in for debugging, just in case
ysr@777 738 gclog_or_tty->print_cr(" fine pass: SO length " SIZE_FORMAT
ysr@777 739 ", setting it to " SIZE_FORMAT,
ysr@777 740 final_so_length, new_so_length);
apetrusenko@980 741 #endif // TRACE_CALC_YOUNG_CONFIG
ysr@777 742
ysr@777 743 from_so_length = new_so_length;
ysr@777 744 to_so_length = new_so_length;
ysr@777 745 fine_so_length = final_so_length;
ysr@777 746
ysr@777 747 pass = pass_type_final;
ysr@777 748 }
ysr@777 749 }
ysr@777 750 } else if (pass == pass_type_final) {
ysr@777 751 // we just finished the final (third) pass
ysr@777 752
ysr@777 753 if (!gc_eff_set)
ysr@777 754 // we didn't find a feasible config, so we'll just use the one
ysr@777 755 // we found during the second pass, which we saved
ysr@777 756 final_so_length = fine_so_length;
ysr@777 757
ysr@777 758 // and we're done!
ysr@777 759 done = true;
ysr@777 760 } else {
ysr@777 761 guarantee( false, "should never reach here" );
ysr@777 762 }
ysr@777 763
ysr@777 764 // we now go around the outermost loop
ysr@777 765 }
ysr@777 766
ysr@777 767 // we should have at least one region in the target young length
apetrusenko@980 768 _young_list_target_length =
apetrusenko@980 769 MAX2((size_t) 1, final_young_length + _recorded_survivor_regions);
ysr@777 770 if (final_so_length >= final_young_length)
ysr@777 771 // and we need to ensure that the S-O length is not greater than
ysr@777 772 // the target young length (this is being a bit careful)
ysr@777 773 final_so_length = 0;
ysr@777 774 _young_list_so_prefix_length = final_so_length;
ysr@777 775 guarantee( !_in_marking_window || !_last_full_young_gc ||
ysr@777 776 _young_list_so_prefix_length == 0, "invariant" );
ysr@777 777
ysr@777 778 // let's keep an eye of how long we spend on this calculation
ysr@777 779 // right now, I assume that we'll print it when we need it; we
ysr@777 780 // should really adde it to the breakdown of a pause
ysr@777 781 double end_time_sec = os::elapsedTime();
ysr@777 782 double elapsed_time_ms = (end_time_sec - start_time_sec) * 1000.0;
ysr@777 783
apetrusenko@980 784 #ifdef TRACE_CALC_YOUNG_CONFIG
ysr@777 785 // leave this in for debugging, just in case
ysr@777 786 gclog_or_tty->print_cr("target = %1.1lf ms, young = " SIZE_FORMAT
ysr@777 787 ", SO = " SIZE_FORMAT ", "
ysr@777 788 "elapsed %1.2lf ms, calcs: " SIZE_FORMAT " (%s%s) "
ysr@777 789 SIZE_FORMAT SIZE_FORMAT,
ysr@777 790 target_pause_time_ms,
ysr@777 791 _young_list_target_length - _young_list_so_prefix_length,
ysr@777 792 _young_list_so_prefix_length,
ysr@777 793 elapsed_time_ms,
ysr@777 794 calculations,
ysr@777 795 full_young_gcs() ? "full" : "partial",
tonyp@1794 796 during_initial_mark_pause() ? " i-m" : "",
apetrusenko@980 797 _in_marking_window,
apetrusenko@980 798 _in_marking_window_im);
apetrusenko@980 799 #endif // TRACE_CALC_YOUNG_CONFIG
ysr@777 800
ysr@777 801 if (_young_list_target_length < _young_list_min_length) {
ysr@777 802 // bummer; this means that, if we do a pause when the optimal
ysr@777 803 // config dictates, we'll violate the pause spacing target (the
ysr@777 804 // min length was calculate based on the application's current
ysr@777 805 // alloc rate);
ysr@777 806
ysr@777 807 // so, we have to bite the bullet, and allocate the minimum
ysr@777 808 // number. We'll violate our target, but we just can't meet it.
ysr@777 809
ysr@777 810 size_t so_length = 0;
ysr@777 811 // a note further up explains why we do not want an S-O length
ysr@777 812 // during marking
ysr@777 813 if (!_in_marking_window && !_last_full_young_gc)
ysr@777 814 // but we can still try to see whether we can find an optimal
ysr@777 815 // S-O length
ysr@777 816 so_length = calculate_optimal_so_length(_young_list_min_length);
ysr@777 817
apetrusenko@980 818 #ifdef TRACE_CALC_YOUNG_CONFIG
ysr@777 819 // leave this in for debugging, just in case
ysr@777 820 gclog_or_tty->print_cr("adjusted target length from "
ysr@777 821 SIZE_FORMAT " to " SIZE_FORMAT
ysr@777 822 ", SO " SIZE_FORMAT,
ysr@777 823 _young_list_target_length, _young_list_min_length,
ysr@777 824 so_length);
apetrusenko@980 825 #endif // TRACE_CALC_YOUNG_CONFIG
ysr@777 826
ysr@777 827 _young_list_target_length =
ysr@777 828 MAX2(_young_list_min_length, (size_t)1);
ysr@777 829 _young_list_so_prefix_length = so_length;
ysr@777 830 }
ysr@777 831 } else {
ysr@777 832 // we are in a partially-young mode or we've run out of regions (due
ysr@777 833 // to evacuation failure)
ysr@777 834
apetrusenko@980 835 #ifdef TRACE_CALC_YOUNG_CONFIG
ysr@777 836 // leave this in for debugging, just in case
ysr@777 837 gclog_or_tty->print_cr("(partial) setting target to " SIZE_FORMAT
ysr@777 838 ", SO " SIZE_FORMAT,
ysr@777 839 _young_list_min_length, 0);
apetrusenko@980 840 #endif // TRACE_CALC_YOUNG_CONFIG
ysr@777 841
ysr@777 842 // we'll do the pause as soon as possible and with no S-O prefix
ysr@777 843 // (see above for the reasons behind the latter)
ysr@777 844 _young_list_target_length =
ysr@777 845 MAX2(_young_list_min_length, (size_t) 1);
ysr@777 846 _young_list_so_prefix_length = 0;
ysr@777 847 }
ysr@777 848
ysr@777 849 _rs_lengths_prediction = rs_lengths;
ysr@777 850 }
ysr@777 851
ysr@777 852 // This is used by: calculate_optimal_so_length(length). It returns
ysr@777 853 // the GC eff and predicted pause time for a particular config
ysr@777 854 void
ysr@777 855 G1CollectorPolicy::predict_gc_eff(size_t young_length,
ysr@777 856 size_t so_length,
ysr@777 857 double base_time_ms,
ysr@777 858 double* ret_gc_eff,
ysr@777 859 double* ret_pause_time_ms) {
ysr@777 860 double so_time_ms = predict_scan_only_time_ms(so_length);
ysr@777 861 double accum_surv_rate_adj = 0.0;
ysr@777 862 if (so_length > 0)
ysr@777 863 accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1));
ysr@777 864 double accum_surv_rate =
ysr@777 865 accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj;
ysr@777 866 size_t bytes_to_copy =
ysr@777 867 (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
ysr@777 868 double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
ysr@777 869 double young_other_time_ms =
ysr@777 870 predict_young_other_time_ms(young_length - so_length);
ysr@777 871 double pause_time_ms =
ysr@777 872 base_time_ms + so_time_ms + copy_time_ms + young_other_time_ms;
ysr@777 873 size_t reclaimed_bytes =
ysr@777 874 (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy;
ysr@777 875 double gc_eff = (double) reclaimed_bytes / pause_time_ms;
ysr@777 876
ysr@777 877 *ret_gc_eff = gc_eff;
ysr@777 878 *ret_pause_time_ms = pause_time_ms;
ysr@777 879 }
ysr@777 880
ysr@777 881 // This is used by: calculate_young_list_target_config(rs_length). It
ysr@777 882 // returns the GC eff of a particular config. It returns false if that
ysr@777 883 // config violates any of the end conditions of the search in the
ysr@777 884 // calling method, or true upon success. The end conditions were put
ysr@777 885 // here since it's called twice and it was best not to replicate them
ysr@777 886 // in the caller. Also, passing the parameteres avoids having to
ysr@777 887 // recalculate them in the innermost loop.
ysr@777 888 bool
ysr@777 889 G1CollectorPolicy::predict_gc_eff(size_t young_length,
ysr@777 890 size_t so_length,
ysr@777 891 double base_time_with_so_ms,
ysr@777 892 size_t init_free_regions,
ysr@777 893 double target_pause_time_ms,
ysr@777 894 double* ret_gc_eff) {
ysr@777 895 *ret_gc_eff = 0.0;
ysr@777 896
ysr@777 897 if (young_length >= init_free_regions)
ysr@777 898 // end condition 1: not enough space for the young regions
ysr@777 899 return false;
ysr@777 900
ysr@777 901 double accum_surv_rate_adj = 0.0;
ysr@777 902 if (so_length > 0)
ysr@777 903 accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1));
ysr@777 904 double accum_surv_rate =
ysr@777 905 accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj;
ysr@777 906 size_t bytes_to_copy =
ysr@777 907 (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
ysr@777 908 double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
ysr@777 909 double young_other_time_ms =
ysr@777 910 predict_young_other_time_ms(young_length - so_length);
ysr@777 911 double pause_time_ms =
ysr@777 912 base_time_with_so_ms + copy_time_ms + young_other_time_ms;
ysr@777 913
ysr@777 914 if (pause_time_ms > target_pause_time_ms)
ysr@777 915 // end condition 2: over the target pause time
ysr@777 916 return false;
ysr@777 917
ysr@777 918 size_t reclaimed_bytes =
ysr@777 919 (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy;
ysr@777 920 size_t free_bytes =
ysr@777 921 (init_free_regions - young_length) * HeapRegion::GrainBytes;
ysr@777 922
ysr@777 923 if ((2.0 + sigma()) * (double) bytes_to_copy > (double) free_bytes)
ysr@777 924 // end condition 3: out of to-space (conservatively)
ysr@777 925 return false;
ysr@777 926
ysr@777 927 // success!
ysr@777 928 double gc_eff = (double) reclaimed_bytes / pause_time_ms;
ysr@777 929 *ret_gc_eff = gc_eff;
ysr@777 930
ysr@777 931 return true;
ysr@777 932 }
ysr@777 933
apetrusenko@980 934 double G1CollectorPolicy::predict_survivor_regions_evac_time() {
apetrusenko@980 935 double survivor_regions_evac_time = 0.0;
apetrusenko@980 936 for (HeapRegion * r = _recorded_survivor_head;
apetrusenko@980 937 r != NULL && r != _recorded_survivor_tail->get_next_young_region();
apetrusenko@980 938 r = r->get_next_young_region()) {
apetrusenko@980 939 survivor_regions_evac_time += predict_region_elapsed_time_ms(r, true);
apetrusenko@980 940 }
apetrusenko@980 941 return survivor_regions_evac_time;
apetrusenko@980 942 }
apetrusenko@980 943
ysr@777 944 void G1CollectorPolicy::check_prediction_validity() {
ysr@777 945 guarantee( adaptive_young_list_length(), "should not call this otherwise" );
ysr@777 946
ysr@777 947 size_t rs_lengths = _g1->young_list_sampled_rs_lengths();
ysr@777 948 if (rs_lengths > _rs_lengths_prediction) {
ysr@777 949 // add 10% to avoid having to recalculate often
ysr@777 950 size_t rs_lengths_prediction = rs_lengths * 1100 / 1000;
ysr@777 951 calculate_young_list_target_config(rs_lengths_prediction);
ysr@777 952 }
ysr@777 953 }
ysr@777 954
ysr@777 955 HeapWord* G1CollectorPolicy::mem_allocate_work(size_t size,
ysr@777 956 bool is_tlab,
ysr@777 957 bool* gc_overhead_limit_was_exceeded) {
ysr@777 958 guarantee(false, "Not using this policy feature yet.");
ysr@777 959 return NULL;
ysr@777 960 }
ysr@777 961
ysr@777 962 // This method controls how a collector handles one or more
ysr@777 963 // of its generations being fully allocated.
ysr@777 964 HeapWord* G1CollectorPolicy::satisfy_failed_allocation(size_t size,
ysr@777 965 bool is_tlab) {
ysr@777 966 guarantee(false, "Not using this policy feature yet.");
ysr@777 967 return NULL;
ysr@777 968 }
ysr@777 969
ysr@777 970
ysr@777 971 #ifndef PRODUCT
ysr@777 972 bool G1CollectorPolicy::verify_young_ages() {
ysr@777 973 HeapRegion* head = _g1->young_list_first_region();
ysr@777 974 return
ysr@777 975 verify_young_ages(head, _short_lived_surv_rate_group);
ysr@777 976 // also call verify_young_ages on any additional surv rate groups
ysr@777 977 }
ysr@777 978
ysr@777 979 bool
ysr@777 980 G1CollectorPolicy::verify_young_ages(HeapRegion* head,
ysr@777 981 SurvRateGroup *surv_rate_group) {
ysr@777 982 guarantee( surv_rate_group != NULL, "pre-condition" );
ysr@777 983
ysr@777 984 const char* name = surv_rate_group->name();
ysr@777 985 bool ret = true;
ysr@777 986 int prev_age = -1;
ysr@777 987
ysr@777 988 for (HeapRegion* curr = head;
ysr@777 989 curr != NULL;
ysr@777 990 curr = curr->get_next_young_region()) {
ysr@777 991 SurvRateGroup* group = curr->surv_rate_group();
ysr@777 992 if (group == NULL && !curr->is_survivor()) {
ysr@777 993 gclog_or_tty->print_cr("## %s: encountered NULL surv_rate_group", name);
ysr@777 994 ret = false;
ysr@777 995 }
ysr@777 996
ysr@777 997 if (surv_rate_group == group) {
ysr@777 998 int age = curr->age_in_surv_rate_group();
ysr@777 999
ysr@777 1000 if (age < 0) {
ysr@777 1001 gclog_or_tty->print_cr("## %s: encountered negative age", name);
ysr@777 1002 ret = false;
ysr@777 1003 }
ysr@777 1004
ysr@777 1005 if (age <= prev_age) {
ysr@777 1006 gclog_or_tty->print_cr("## %s: region ages are not strictly increasing "
ysr@777 1007 "(%d, %d)", name, age, prev_age);
ysr@777 1008 ret = false;
ysr@777 1009 }
ysr@777 1010 prev_age = age;
ysr@777 1011 }
ysr@777 1012 }
ysr@777 1013
ysr@777 1014 return ret;
ysr@777 1015 }
ysr@777 1016 #endif // PRODUCT
ysr@777 1017
ysr@777 1018 void G1CollectorPolicy::record_full_collection_start() {
ysr@777 1019 _cur_collection_start_sec = os::elapsedTime();
ysr@777 1020 // Release the future to-space so that it is available for compaction into.
ysr@777 1021 _g1->set_full_collection();
ysr@777 1022 }
ysr@777 1023
ysr@777 1024 void G1CollectorPolicy::record_full_collection_end() {
ysr@777 1025 // Consider this like a collection pause for the purposes of allocation
ysr@777 1026 // since last pause.
ysr@777 1027 double end_sec = os::elapsedTime();
ysr@777 1028 double full_gc_time_sec = end_sec - _cur_collection_start_sec;
ysr@777 1029 double full_gc_time_ms = full_gc_time_sec * 1000.0;
ysr@777 1030
ysr@777 1031 _all_full_gc_times_ms->add(full_gc_time_ms);
ysr@777 1032
tonyp@1030 1033 update_recent_gc_times(end_sec, full_gc_time_ms);
ysr@777 1034
ysr@777 1035 _g1->clear_full_collection();
ysr@777 1036
ysr@777 1037 // "Nuke" the heuristics that control the fully/partially young GC
ysr@777 1038 // transitions and make sure we start with fully young GCs after the
ysr@777 1039 // Full GC.
ysr@777 1040 set_full_young_gcs(true);
ysr@777 1041 _last_full_young_gc = false;
ysr@777 1042 _should_revert_to_full_young_gcs = false;
tonyp@1794 1043 clear_initiate_conc_mark_if_possible();
tonyp@1794 1044 clear_during_initial_mark_pause();
ysr@777 1045 _known_garbage_bytes = 0;
ysr@777 1046 _known_garbage_ratio = 0.0;
ysr@777 1047 _in_marking_window = false;
ysr@777 1048 _in_marking_window_im = false;
ysr@777 1049
ysr@777 1050 _short_lived_surv_rate_group->record_scan_only_prefix(0);
ysr@777 1051 _short_lived_surv_rate_group->start_adding_regions();
ysr@777 1052 // also call this on any additional surv rate groups
ysr@777 1053
apetrusenko@980 1054 record_survivor_regions(0, NULL, NULL);
apetrusenko@980 1055
ysr@777 1056 _prev_region_num_young = _region_num_young;
ysr@777 1057 _prev_region_num_tenured = _region_num_tenured;
ysr@777 1058
ysr@777 1059 _free_regions_at_end_of_collection = _g1->free_regions();
ysr@777 1060 _scan_only_regions_at_end_of_collection = 0;
apetrusenko@980 1061 // Reset survivors SurvRateGroup.
apetrusenko@980 1062 _survivor_surv_rate_group->reset();
ysr@777 1063 calculate_young_list_min_length();
ysr@777 1064 calculate_young_list_target_config();
ysr@777 1065 }
ysr@777 1066
ysr@777 1067 void G1CollectorPolicy::record_before_bytes(size_t bytes) {
ysr@777 1068 _bytes_in_to_space_before_gc += bytes;
ysr@777 1069 }
ysr@777 1070
ysr@777 1071 void G1CollectorPolicy::record_after_bytes(size_t bytes) {
ysr@777 1072 _bytes_in_to_space_after_gc += bytes;
ysr@777 1073 }
ysr@777 1074
ysr@777 1075 void G1CollectorPolicy::record_stop_world_start() {
ysr@777 1076 _stop_world_start = os::elapsedTime();
ysr@777 1077 }
ysr@777 1078
ysr@777 1079 void G1CollectorPolicy::record_collection_pause_start(double start_time_sec,
ysr@777 1080 size_t start_used) {
ysr@777 1081 if (PrintGCDetails) {
ysr@777 1082 gclog_or_tty->stamp(PrintGCTimeStamps);
ysr@777 1083 gclog_or_tty->print("[GC pause");
ysr@777 1084 if (in_young_gc_mode())
ysr@777 1085 gclog_or_tty->print(" (%s)", full_young_gcs() ? "young" : "partial");
ysr@777 1086 }
ysr@777 1087
ysr@777 1088 assert(_g1->used_regions() == _g1->recalculate_used_regions(),
ysr@777 1089 "sanity");
tonyp@1071 1090 assert(_g1->used() == _g1->recalculate_used(), "sanity");
ysr@777 1091
ysr@777 1092 double s_w_t_ms = (start_time_sec - _stop_world_start) * 1000.0;
ysr@777 1093 _all_stop_world_times_ms->add(s_w_t_ms);
ysr@777 1094 _stop_world_start = 0.0;
ysr@777 1095
ysr@777 1096 _cur_collection_start_sec = start_time_sec;
ysr@777 1097 _cur_collection_pause_used_at_start_bytes = start_used;
ysr@777 1098 _cur_collection_pause_used_regions_at_start = _g1->used_regions();
ysr@777 1099 _pending_cards = _g1->pending_card_num();
ysr@777 1100 _max_pending_cards = _g1->max_pending_card_num();
ysr@777 1101
ysr@777 1102 _bytes_in_to_space_before_gc = 0;
ysr@777 1103 _bytes_in_to_space_after_gc = 0;
ysr@777 1104 _bytes_in_collection_set_before_gc = 0;
ysr@777 1105
ysr@777 1106 #ifdef DEBUG
ysr@777 1107 // initialise these to something well known so that we can spot
ysr@777 1108 // if they are not set properly
ysr@777 1109
ysr@777 1110 for (int i = 0; i < _parallel_gc_threads; ++i) {
ysr@777 1111 _par_last_ext_root_scan_times_ms[i] = -666.0;
ysr@777 1112 _par_last_mark_stack_scan_times_ms[i] = -666.0;
ysr@777 1113 _par_last_scan_only_times_ms[i] = -666.0;
ysr@777 1114 _par_last_scan_only_regions_scanned[i] = -666.0;
ysr@777 1115 _par_last_update_rs_start_times_ms[i] = -666.0;
ysr@777 1116 _par_last_update_rs_times_ms[i] = -666.0;
ysr@777 1117 _par_last_update_rs_processed_buffers[i] = -666.0;
ysr@777 1118 _par_last_scan_rs_start_times_ms[i] = -666.0;
ysr@777 1119 _par_last_scan_rs_times_ms[i] = -666.0;
ysr@777 1120 _par_last_scan_new_refs_times_ms[i] = -666.0;
ysr@777 1121 _par_last_obj_copy_times_ms[i] = -666.0;
ysr@777 1122 _par_last_termination_times_ms[i] = -666.0;
ysr@777 1123 }
ysr@777 1124 #endif
ysr@777 1125
ysr@777 1126 for (int i = 0; i < _aux_num; ++i) {
ysr@777 1127 _cur_aux_times_ms[i] = 0.0;
ysr@777 1128 _cur_aux_times_set[i] = false;
ysr@777 1129 }
ysr@777 1130
ysr@777 1131 _satb_drain_time_set = false;
ysr@777 1132 _last_satb_drain_processed_buffers = -1;
ysr@777 1133
ysr@777 1134 if (in_young_gc_mode())
ysr@777 1135 _last_young_gc_full = false;
ysr@777 1136
ysr@777 1137
ysr@777 1138 // do that for any other surv rate groups
ysr@777 1139 _short_lived_surv_rate_group->stop_adding_regions();
ysr@777 1140 size_t short_lived_so_length = _young_list_so_prefix_length;
ysr@777 1141 _short_lived_surv_rate_group->record_scan_only_prefix(short_lived_so_length);
ysr@777 1142 tag_scan_only(short_lived_so_length);
tonyp@1717 1143 _survivors_age_table.clear();
apetrusenko@980 1144
ysr@777 1145 assert( verify_young_ages(), "region age verification" );
ysr@777 1146 }
ysr@777 1147
ysr@777 1148 void G1CollectorPolicy::tag_scan_only(size_t short_lived_scan_only_length) {
ysr@777 1149 // done in a way that it can be extended for other surv rate groups too...
ysr@777 1150
ysr@777 1151 HeapRegion* head = _g1->young_list_first_region();
ysr@777 1152 bool finished_short_lived = (short_lived_scan_only_length == 0);
ysr@777 1153
ysr@777 1154 if (finished_short_lived)
ysr@777 1155 return;
ysr@777 1156
ysr@777 1157 for (HeapRegion* curr = head;
ysr@777 1158 curr != NULL;
ysr@777 1159 curr = curr->get_next_young_region()) {
ysr@777 1160 SurvRateGroup* surv_rate_group = curr->surv_rate_group();
ysr@777 1161 int age = curr->age_in_surv_rate_group();
ysr@777 1162
ysr@777 1163 if (surv_rate_group == _short_lived_surv_rate_group) {
ysr@777 1164 if ((size_t)age < short_lived_scan_only_length)
ysr@777 1165 curr->set_scan_only();
ysr@777 1166 else
ysr@777 1167 finished_short_lived = true;
ysr@777 1168 }
ysr@777 1169
ysr@777 1170
ysr@777 1171 if (finished_short_lived)
ysr@777 1172 return;
ysr@777 1173 }
ysr@777 1174
ysr@777 1175 guarantee( false, "we should never reach here" );
ysr@777 1176 }
ysr@777 1177
ysr@777 1178 void G1CollectorPolicy::record_mark_closure_time(double mark_closure_time_ms) {
ysr@777 1179 _mark_closure_time_ms = mark_closure_time_ms;
ysr@777 1180 }
ysr@777 1181
ysr@777 1182 void G1CollectorPolicy::record_concurrent_mark_init_start() {
ysr@777 1183 _mark_init_start_sec = os::elapsedTime();
ysr@777 1184 guarantee(!in_young_gc_mode(), "should not do be here in young GC mode");
ysr@777 1185 }
ysr@777 1186
ysr@777 1187 void G1CollectorPolicy::record_concurrent_mark_init_end_pre(double
ysr@777 1188 mark_init_elapsed_time_ms) {
ysr@777 1189 _during_marking = true;
tonyp@1794 1190 assert(!initiate_conc_mark_if_possible(), "we should have cleared it by now");
tonyp@1794 1191 clear_during_initial_mark_pause();
ysr@777 1192 _cur_mark_stop_world_time_ms = mark_init_elapsed_time_ms;
ysr@777 1193 }
ysr@777 1194
ysr@777 1195 void G1CollectorPolicy::record_concurrent_mark_init_end() {
ysr@777 1196 double end_time_sec = os::elapsedTime();
ysr@777 1197 double elapsed_time_ms = (end_time_sec - _mark_init_start_sec) * 1000.0;
ysr@777 1198 _concurrent_mark_init_times_ms->add(elapsed_time_ms);
ysr@777 1199 record_concurrent_mark_init_end_pre(elapsed_time_ms);
ysr@777 1200
ysr@777 1201 _mmu_tracker->add_pause(_mark_init_start_sec, end_time_sec, true);
ysr@777 1202 }
ysr@777 1203
ysr@777 1204 void G1CollectorPolicy::record_concurrent_mark_remark_start() {
ysr@777 1205 _mark_remark_start_sec = os::elapsedTime();
ysr@777 1206 _during_marking = false;
ysr@777 1207 }
ysr@777 1208
ysr@777 1209 void G1CollectorPolicy::record_concurrent_mark_remark_end() {
ysr@777 1210 double end_time_sec = os::elapsedTime();
ysr@777 1211 double elapsed_time_ms = (end_time_sec - _mark_remark_start_sec)*1000.0;
ysr@777 1212 _concurrent_mark_remark_times_ms->add(elapsed_time_ms);
ysr@777 1213 _cur_mark_stop_world_time_ms += elapsed_time_ms;
ysr@777 1214 _prev_collection_pause_end_ms += elapsed_time_ms;
ysr@777 1215
ysr@777 1216 _mmu_tracker->add_pause(_mark_remark_start_sec, end_time_sec, true);
ysr@777 1217 }
ysr@777 1218
ysr@777 1219 void G1CollectorPolicy::record_concurrent_mark_cleanup_start() {
ysr@777 1220 _mark_cleanup_start_sec = os::elapsedTime();
ysr@777 1221 }
ysr@777 1222
ysr@777 1223 void
ysr@777 1224 G1CollectorPolicy::record_concurrent_mark_cleanup_end(size_t freed_bytes,
ysr@777 1225 size_t max_live_bytes) {
ysr@777 1226 record_concurrent_mark_cleanup_end_work1(freed_bytes, max_live_bytes);
ysr@777 1227 record_concurrent_mark_cleanup_end_work2();
ysr@777 1228 }
ysr@777 1229
ysr@777 1230 void
ysr@777 1231 G1CollectorPolicy::
ysr@777 1232 record_concurrent_mark_cleanup_end_work1(size_t freed_bytes,
ysr@777 1233 size_t max_live_bytes) {
ysr@777 1234 if (_n_marks < 2) _n_marks++;
ysr@777 1235 if (G1PolicyVerbose > 0)
ysr@777 1236 gclog_or_tty->print_cr("At end of marking, max_live is " SIZE_FORMAT " MB "
ysr@777 1237 " (of " SIZE_FORMAT " MB heap).",
ysr@777 1238 max_live_bytes/M, _g1->capacity()/M);
ysr@777 1239 }
ysr@777 1240
ysr@777 1241 // The important thing about this is that it includes "os::elapsedTime".
ysr@777 1242 void G1CollectorPolicy::record_concurrent_mark_cleanup_end_work2() {
ysr@777 1243 double end_time_sec = os::elapsedTime();
ysr@777 1244 double elapsed_time_ms = (end_time_sec - _mark_cleanup_start_sec)*1000.0;
ysr@777 1245 _concurrent_mark_cleanup_times_ms->add(elapsed_time_ms);
ysr@777 1246 _cur_mark_stop_world_time_ms += elapsed_time_ms;
ysr@777 1247 _prev_collection_pause_end_ms += elapsed_time_ms;
ysr@777 1248
ysr@777 1249 _mmu_tracker->add_pause(_mark_cleanup_start_sec, end_time_sec, true);
ysr@777 1250
ysr@777 1251 _num_markings++;
ysr@777 1252
ysr@777 1253 // We did a marking, so reset the "since_last_mark" variables.
ysr@777 1254 double considerConcMarkCost = 1.0;
ysr@777 1255 // If there are available processors, concurrent activity is free...
ysr@777 1256 if (Threads::number_of_non_daemon_threads() * 2 <
ysr@777 1257 os::active_processor_count()) {
ysr@777 1258 considerConcMarkCost = 0.0;
ysr@777 1259 }
ysr@777 1260 _n_pauses_at_mark_end = _n_pauses;
ysr@777 1261 _n_marks_since_last_pause++;
ysr@777 1262 }
ysr@777 1263
ysr@777 1264 void
ysr@777 1265 G1CollectorPolicy::record_concurrent_mark_cleanup_completed() {
ysr@777 1266 if (in_young_gc_mode()) {
ysr@777 1267 _should_revert_to_full_young_gcs = false;
ysr@777 1268 _last_full_young_gc = true;
ysr@777 1269 _in_marking_window = false;
ysr@777 1270 if (adaptive_young_list_length())
ysr@777 1271 calculate_young_list_target_config();
ysr@777 1272 }
ysr@777 1273 }
ysr@777 1274
ysr@777 1275 void G1CollectorPolicy::record_concurrent_pause() {
ysr@777 1276 if (_stop_world_start > 0.0) {
ysr@777 1277 double yield_ms = (os::elapsedTime() - _stop_world_start) * 1000.0;
ysr@777 1278 _all_yield_times_ms->add(yield_ms);
ysr@777 1279 }
ysr@777 1280 }
ysr@777 1281
ysr@777 1282 void G1CollectorPolicy::record_concurrent_pause_end() {
ysr@777 1283 }
ysr@777 1284
ysr@777 1285 void G1CollectorPolicy::record_collection_pause_end_CH_strong_roots() {
ysr@777 1286 _cur_CH_strong_roots_end_sec = os::elapsedTime();
ysr@777 1287 _cur_CH_strong_roots_dur_ms =
ysr@777 1288 (_cur_CH_strong_roots_end_sec - _cur_collection_start_sec) * 1000.0;
ysr@777 1289 }
ysr@777 1290
ysr@777 1291 void G1CollectorPolicy::record_collection_pause_end_G1_strong_roots() {
ysr@777 1292 _cur_G1_strong_roots_end_sec = os::elapsedTime();
ysr@777 1293 _cur_G1_strong_roots_dur_ms =
ysr@777 1294 (_cur_G1_strong_roots_end_sec - _cur_CH_strong_roots_end_sec) * 1000.0;
ysr@777 1295 }
ysr@777 1296
ysr@777 1297 template<class T>
ysr@777 1298 T sum_of(T* sum_arr, int start, int n, int N) {
ysr@777 1299 T sum = (T)0;
ysr@777 1300 for (int i = 0; i < n; i++) {
ysr@777 1301 int j = (start + i) % N;
ysr@777 1302 sum += sum_arr[j];
ysr@777 1303 }
ysr@777 1304 return sum;
ysr@777 1305 }
ysr@777 1306
ysr@777 1307 void G1CollectorPolicy::print_par_stats (int level,
ysr@777 1308 const char* str,
ysr@777 1309 double* data,
ysr@777 1310 bool summary) {
ysr@777 1311 double min = data[0], max = data[0];
ysr@777 1312 double total = 0.0;
ysr@777 1313 int j;
ysr@777 1314 for (j = 0; j < level; ++j)
ysr@777 1315 gclog_or_tty->print(" ");
ysr@777 1316 gclog_or_tty->print("[%s (ms):", str);
ysr@777 1317 for (uint i = 0; i < ParallelGCThreads; ++i) {
ysr@777 1318 double val = data[i];
ysr@777 1319 if (val < min)
ysr@777 1320 min = val;
ysr@777 1321 if (val > max)
ysr@777 1322 max = val;
ysr@777 1323 total += val;
ysr@777 1324 gclog_or_tty->print(" %3.1lf", val);
ysr@777 1325 }
ysr@777 1326 if (summary) {
ysr@777 1327 gclog_or_tty->print_cr("");
ysr@777 1328 double avg = total / (double) ParallelGCThreads;
ysr@777 1329 gclog_or_tty->print(" ");
ysr@777 1330 for (j = 0; j < level; ++j)
ysr@777 1331 gclog_or_tty->print(" ");
ysr@777 1332 gclog_or_tty->print("Avg: %5.1lf, Min: %5.1lf, Max: %5.1lf",
ysr@777 1333 avg, min, max);
ysr@777 1334 }
ysr@777 1335 gclog_or_tty->print_cr("]");
ysr@777 1336 }
ysr@777 1337
ysr@777 1338 void G1CollectorPolicy::print_par_buffers (int level,
ysr@777 1339 const char* str,
ysr@777 1340 double* data,
ysr@777 1341 bool summary) {
ysr@777 1342 double min = data[0], max = data[0];
ysr@777 1343 double total = 0.0;
ysr@777 1344 int j;
ysr@777 1345 for (j = 0; j < level; ++j)
ysr@777 1346 gclog_or_tty->print(" ");
ysr@777 1347 gclog_or_tty->print("[%s :", str);
ysr@777 1348 for (uint i = 0; i < ParallelGCThreads; ++i) {
ysr@777 1349 double val = data[i];
ysr@777 1350 if (val < min)
ysr@777 1351 min = val;
ysr@777 1352 if (val > max)
ysr@777 1353 max = val;
ysr@777 1354 total += val;
ysr@777 1355 gclog_or_tty->print(" %d", (int) val);
ysr@777 1356 }
ysr@777 1357 if (summary) {
ysr@777 1358 gclog_or_tty->print_cr("");
ysr@777 1359 double avg = total / (double) ParallelGCThreads;
ysr@777 1360 gclog_or_tty->print(" ");
ysr@777 1361 for (j = 0; j < level; ++j)
ysr@777 1362 gclog_or_tty->print(" ");
ysr@777 1363 gclog_or_tty->print("Sum: %d, Avg: %d, Min: %d, Max: %d",
ysr@777 1364 (int)total, (int)avg, (int)min, (int)max);
ysr@777 1365 }
ysr@777 1366 gclog_or_tty->print_cr("]");
ysr@777 1367 }
ysr@777 1368
ysr@777 1369 void G1CollectorPolicy::print_stats (int level,
ysr@777 1370 const char* str,
ysr@777 1371 double value) {
ysr@777 1372 for (int j = 0; j < level; ++j)
ysr@777 1373 gclog_or_tty->print(" ");
ysr@777 1374 gclog_or_tty->print_cr("[%s: %5.1lf ms]", str, value);
ysr@777 1375 }
ysr@777 1376
ysr@777 1377 void G1CollectorPolicy::print_stats (int level,
ysr@777 1378 const char* str,
ysr@777 1379 int value) {
ysr@777 1380 for (int j = 0; j < level; ++j)
ysr@777 1381 gclog_or_tty->print(" ");
ysr@777 1382 gclog_or_tty->print_cr("[%s: %d]", str, value);
ysr@777 1383 }
ysr@777 1384
ysr@777 1385 double G1CollectorPolicy::avg_value (double* data) {
ysr@777 1386 if (ParallelGCThreads > 0) {
ysr@777 1387 double ret = 0.0;
ysr@777 1388 for (uint i = 0; i < ParallelGCThreads; ++i)
ysr@777 1389 ret += data[i];
ysr@777 1390 return ret / (double) ParallelGCThreads;
ysr@777 1391 } else {
ysr@777 1392 return data[0];
ysr@777 1393 }
ysr@777 1394 }
ysr@777 1395
ysr@777 1396 double G1CollectorPolicy::max_value (double* data) {
ysr@777 1397 if (ParallelGCThreads > 0) {
ysr@777 1398 double ret = data[0];
ysr@777 1399 for (uint i = 1; i < ParallelGCThreads; ++i)
ysr@777 1400 if (data[i] > ret)
ysr@777 1401 ret = data[i];
ysr@777 1402 return ret;
ysr@777 1403 } else {
ysr@777 1404 return data[0];
ysr@777 1405 }
ysr@777 1406 }
ysr@777 1407
ysr@777 1408 double G1CollectorPolicy::sum_of_values (double* data) {
ysr@777 1409 if (ParallelGCThreads > 0) {
ysr@777 1410 double sum = 0.0;
ysr@777 1411 for (uint i = 0; i < ParallelGCThreads; i++)
ysr@777 1412 sum += data[i];
ysr@777 1413 return sum;
ysr@777 1414 } else {
ysr@777 1415 return data[0];
ysr@777 1416 }
ysr@777 1417 }
ysr@777 1418
ysr@777 1419 double G1CollectorPolicy::max_sum (double* data1,
ysr@777 1420 double* data2) {
ysr@777 1421 double ret = data1[0] + data2[0];
ysr@777 1422
ysr@777 1423 if (ParallelGCThreads > 0) {
ysr@777 1424 for (uint i = 1; i < ParallelGCThreads; ++i) {
ysr@777 1425 double data = data1[i] + data2[i];
ysr@777 1426 if (data > ret)
ysr@777 1427 ret = data;
ysr@777 1428 }
ysr@777 1429 }
ysr@777 1430 return ret;
ysr@777 1431 }
ysr@777 1432
ysr@777 1433 // Anything below that is considered to be zero
ysr@777 1434 #define MIN_TIMER_GRANULARITY 0.0000001
ysr@777 1435
apetrusenko@1112 1436 void G1CollectorPolicy::record_collection_pause_end(bool abandoned) {
ysr@777 1437 double end_time_sec = os::elapsedTime();
ysr@777 1438 double elapsed_ms = _last_pause_time_ms;
ysr@777 1439 bool parallel = ParallelGCThreads > 0;
ysr@777 1440 double evac_ms = (end_time_sec - _cur_G1_strong_roots_end_sec) * 1000.0;
ysr@777 1441 size_t rs_size =
ysr@777 1442 _cur_collection_pause_used_regions_at_start - collection_set_size();
ysr@777 1443 size_t cur_used_bytes = _g1->used();
ysr@777 1444 assert(cur_used_bytes == _g1->recalculate_used(), "It should!");
ysr@777 1445 bool last_pause_included_initial_mark = false;
tonyp@1030 1446 bool update_stats = !abandoned && !_g1->evacuation_failed();
ysr@777 1447
ysr@777 1448 #ifndef PRODUCT
ysr@777 1449 if (G1YoungSurvRateVerbose) {
ysr@777 1450 gclog_or_tty->print_cr("");
ysr@777 1451 _short_lived_surv_rate_group->print();
ysr@777 1452 // do that for any other surv rate groups too
ysr@777 1453 }
ysr@777 1454 #endif // PRODUCT
ysr@777 1455
ysr@777 1456 if (in_young_gc_mode()) {
tonyp@1794 1457 last_pause_included_initial_mark = during_initial_mark_pause();
ysr@777 1458 if (last_pause_included_initial_mark)
ysr@777 1459 record_concurrent_mark_init_end_pre(0.0);
ysr@777 1460
ysr@777 1461 size_t min_used_targ =
tonyp@1718 1462 (_g1->capacity() / 100) * InitiatingHeapOccupancyPercent;
ysr@777 1463
tonyp@1794 1464
tonyp@1794 1465 if (!_g1->mark_in_progress() && !_last_full_young_gc) {
tonyp@1794 1466 assert(!last_pause_included_initial_mark, "invariant");
tonyp@1794 1467 if (cur_used_bytes > min_used_targ &&
tonyp@1794 1468 cur_used_bytes > _prev_collection_pause_used_at_end_bytes) {
tonyp@1794 1469 assert(!during_initial_mark_pause(), "we should not see this here");
tonyp@1794 1470
tonyp@1794 1471 // Note: this might have already been set, if during the last
tonyp@1794 1472 // pause we decided to start a cycle but at the beginning of
tonyp@1794 1473 // this pause we decided to postpone it. That's OK.
tonyp@1794 1474 set_initiate_conc_mark_if_possible();
ysr@777 1475 }
ysr@777 1476 }
ysr@777 1477
ysr@777 1478 _prev_collection_pause_used_at_end_bytes = cur_used_bytes;
ysr@777 1479 }
ysr@777 1480
ysr@777 1481 _mmu_tracker->add_pause(end_time_sec - elapsed_ms/1000.0,
ysr@777 1482 end_time_sec, false);
ysr@777 1483
ysr@777 1484 guarantee(_cur_collection_pause_used_regions_at_start >=
ysr@777 1485 collection_set_size(),
ysr@777 1486 "Negative RS size?");
ysr@777 1487
ysr@777 1488 // This assert is exempted when we're doing parallel collection pauses,
ysr@777 1489 // because the fragmentation caused by the parallel GC allocation buffers
ysr@777 1490 // can lead to more memory being used during collection than was used
ysr@777 1491 // before. Best leave this out until the fragmentation problem is fixed.
ysr@777 1492 // Pauses in which evacuation failed can also lead to negative
ysr@777 1493 // collections, since no space is reclaimed from a region containing an
ysr@777 1494 // object whose evacuation failed.
ysr@777 1495 // Further, we're now always doing parallel collection. But I'm still
ysr@777 1496 // leaving this here as a placeholder for a more precise assertion later.
ysr@777 1497 // (DLD, 10/05.)
ysr@777 1498 assert((true || parallel) // Always using GC LABs now.
ysr@777 1499 || _g1->evacuation_failed()
ysr@777 1500 || _cur_collection_pause_used_at_start_bytes >= cur_used_bytes,
ysr@777 1501 "Negative collection");
ysr@777 1502
ysr@777 1503 size_t freed_bytes =
ysr@777 1504 _cur_collection_pause_used_at_start_bytes - cur_used_bytes;
ysr@777 1505 size_t surviving_bytes = _collection_set_bytes_used_before - freed_bytes;
ysr@777 1506 double survival_fraction =
ysr@777 1507 (double)surviving_bytes/
ysr@777 1508 (double)_collection_set_bytes_used_before;
ysr@777 1509
ysr@777 1510 _n_pauses++;
ysr@777 1511
tonyp@1030 1512 if (update_stats) {
ysr@777 1513 _recent_CH_strong_roots_times_ms->add(_cur_CH_strong_roots_dur_ms);
ysr@777 1514 _recent_G1_strong_roots_times_ms->add(_cur_G1_strong_roots_dur_ms);
ysr@777 1515 _recent_evac_times_ms->add(evac_ms);
ysr@777 1516 _recent_pause_times_ms->add(elapsed_ms);
ysr@777 1517
ysr@777 1518 _recent_rs_sizes->add(rs_size);
ysr@777 1519
ysr@777 1520 // We exempt parallel collection from this check because Alloc Buffer
ysr@777 1521 // fragmentation can produce negative collections. Same with evac
ysr@777 1522 // failure.
ysr@777 1523 // Further, we're now always doing parallel collection. But I'm still
ysr@777 1524 // leaving this here as a placeholder for a more precise assertion later.
ysr@777 1525 // (DLD, 10/05.
ysr@777 1526 assert((true || parallel)
ysr@777 1527 || _g1->evacuation_failed()
ysr@777 1528 || surviving_bytes <= _collection_set_bytes_used_before,
ysr@777 1529 "Or else negative collection!");
ysr@777 1530 _recent_CS_bytes_used_before->add(_collection_set_bytes_used_before);
ysr@777 1531 _recent_CS_bytes_surviving->add(surviving_bytes);
ysr@777 1532
ysr@777 1533 // this is where we update the allocation rate of the application
ysr@777 1534 double app_time_ms =
ysr@777 1535 (_cur_collection_start_sec * 1000.0 - _prev_collection_pause_end_ms);
ysr@777 1536 if (app_time_ms < MIN_TIMER_GRANULARITY) {
ysr@777 1537 // This usually happens due to the timer not having the required
ysr@777 1538 // granularity. Some Linuxes are the usual culprits.
ysr@777 1539 // We'll just set it to something (arbitrarily) small.
ysr@777 1540 app_time_ms = 1.0;
ysr@777 1541 }
ysr@777 1542 size_t regions_allocated =
ysr@777 1543 (_region_num_young - _prev_region_num_young) +
ysr@777 1544 (_region_num_tenured - _prev_region_num_tenured);
ysr@777 1545 double alloc_rate_ms = (double) regions_allocated / app_time_ms;
ysr@777 1546 _alloc_rate_ms_seq->add(alloc_rate_ms);
ysr@777 1547 _prev_region_num_young = _region_num_young;
ysr@777 1548 _prev_region_num_tenured = _region_num_tenured;
ysr@777 1549
ysr@777 1550 double interval_ms =
ysr@777 1551 (end_time_sec - _recent_prev_end_times_for_all_gcs_sec->oldest()) * 1000.0;
ysr@777 1552 update_recent_gc_times(end_time_sec, elapsed_ms);
ysr@777 1553 _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum()/interval_ms;
ysr@1521 1554 if (recent_avg_pause_time_ratio() < 0.0 ||
ysr@1521 1555 (recent_avg_pause_time_ratio() - 1.0 > 0.0)) {
ysr@1521 1556 #ifndef PRODUCT
ysr@1521 1557 // Dump info to allow post-facto debugging
ysr@1521 1558 gclog_or_tty->print_cr("recent_avg_pause_time_ratio() out of bounds");
ysr@1521 1559 gclog_or_tty->print_cr("-------------------------------------------");
ysr@1521 1560 gclog_or_tty->print_cr("Recent GC Times (ms):");
ysr@1521 1561 _recent_gc_times_ms->dump();
ysr@1521 1562 gclog_or_tty->print_cr("(End Time=%3.3f) Recent GC End Times (s):", end_time_sec);
ysr@1521 1563 _recent_prev_end_times_for_all_gcs_sec->dump();
ysr@1521 1564 gclog_or_tty->print_cr("GC = %3.3f, Interval = %3.3f, Ratio = %3.3f",
ysr@1521 1565 _recent_gc_times_ms->sum(), interval_ms, recent_avg_pause_time_ratio());
ysr@1522 1566 // In debug mode, terminate the JVM if the user wants to debug at this point.
ysr@1522 1567 assert(!G1FailOnFPError, "Debugging data for CR 6898948 has been dumped above");
ysr@1522 1568 #endif // !PRODUCT
ysr@1522 1569 // Clip ratio between 0.0 and 1.0, and continue. This will be fixed in
ysr@1522 1570 // CR 6902692 by redoing the manner in which the ratio is incrementally computed.
ysr@1521 1571 if (_recent_avg_pause_time_ratio < 0.0) {
ysr@1521 1572 _recent_avg_pause_time_ratio = 0.0;
ysr@1521 1573 } else {
ysr@1521 1574 assert(_recent_avg_pause_time_ratio - 1.0 > 0.0, "Ctl-point invariant");
ysr@1521 1575 _recent_avg_pause_time_ratio = 1.0;
ysr@1521 1576 }
ysr@1521 1577 }
ysr@777 1578 }
ysr@777 1579
ysr@777 1580 if (G1PolicyVerbose > 1) {
ysr@777 1581 gclog_or_tty->print_cr(" Recording collection pause(%d)", _n_pauses);
ysr@777 1582 }
ysr@777 1583
ysr@777 1584 PauseSummary* summary;
apetrusenko@1112 1585 if (abandoned) {
apetrusenko@1112 1586 summary = _abandoned_summary;
apetrusenko@1112 1587 } else {
apetrusenko@1112 1588 summary = _summary;
ysr@777 1589 }
ysr@777 1590
ysr@777 1591 double ext_root_scan_time = avg_value(_par_last_ext_root_scan_times_ms);
ysr@777 1592 double mark_stack_scan_time = avg_value(_par_last_mark_stack_scan_times_ms);
ysr@777 1593 double scan_only_time = avg_value(_par_last_scan_only_times_ms);
ysr@777 1594 double scan_only_regions_scanned =
ysr@777 1595 sum_of_values(_par_last_scan_only_regions_scanned);
ysr@777 1596 double update_rs_time = avg_value(_par_last_update_rs_times_ms);
ysr@777 1597 double update_rs_processed_buffers =
ysr@777 1598 sum_of_values(_par_last_update_rs_processed_buffers);
ysr@777 1599 double scan_rs_time = avg_value(_par_last_scan_rs_times_ms);
ysr@777 1600 double obj_copy_time = avg_value(_par_last_obj_copy_times_ms);
ysr@777 1601 double termination_time = avg_value(_par_last_termination_times_ms);
ysr@777 1602
tonyp@1083 1603 double parallel_other_time = _cur_collection_par_time_ms -
tonyp@1083 1604 (update_rs_time + ext_root_scan_time + mark_stack_scan_time +
tonyp@1083 1605 scan_only_time + scan_rs_time + obj_copy_time + termination_time);
tonyp@1030 1606 if (update_stats) {
ysr@777 1607 MainBodySummary* body_summary = summary->main_body_summary();
ysr@777 1608 guarantee(body_summary != NULL, "should not be null!");
ysr@777 1609
ysr@777 1610 if (_satb_drain_time_set)
ysr@777 1611 body_summary->record_satb_drain_time_ms(_cur_satb_drain_time_ms);
ysr@777 1612 else
ysr@777 1613 body_summary->record_satb_drain_time_ms(0.0);
ysr@777 1614 body_summary->record_ext_root_scan_time_ms(ext_root_scan_time);
ysr@777 1615 body_summary->record_mark_stack_scan_time_ms(mark_stack_scan_time);
ysr@777 1616 body_summary->record_scan_only_time_ms(scan_only_time);
ysr@777 1617 body_summary->record_update_rs_time_ms(update_rs_time);
ysr@777 1618 body_summary->record_scan_rs_time_ms(scan_rs_time);
ysr@777 1619 body_summary->record_obj_copy_time_ms(obj_copy_time);
ysr@777 1620 if (parallel) {
ysr@777 1621 body_summary->record_parallel_time_ms(_cur_collection_par_time_ms);
ysr@777 1622 body_summary->record_clear_ct_time_ms(_cur_clear_ct_time_ms);
ysr@777 1623 body_summary->record_termination_time_ms(termination_time);
ysr@777 1624 body_summary->record_parallel_other_time_ms(parallel_other_time);
ysr@777 1625 }
ysr@777 1626 body_summary->record_mark_closure_time_ms(_mark_closure_time_ms);
ysr@777 1627 }
ysr@777 1628
ysr@777 1629 if (G1PolicyVerbose > 1) {
ysr@777 1630 gclog_or_tty->print_cr(" ET: %10.6f ms (avg: %10.6f ms)\n"
ysr@777 1631 " CH Strong: %10.6f ms (avg: %10.6f ms)\n"
ysr@777 1632 " G1 Strong: %10.6f ms (avg: %10.6f ms)\n"
ysr@777 1633 " Evac: %10.6f ms (avg: %10.6f ms)\n"
ysr@777 1634 " ET-RS: %10.6f ms (avg: %10.6f ms)\n"
ysr@777 1635 " |RS|: " SIZE_FORMAT,
ysr@777 1636 elapsed_ms, recent_avg_time_for_pauses_ms(),
ysr@777 1637 _cur_CH_strong_roots_dur_ms, recent_avg_time_for_CH_strong_ms(),
ysr@777 1638 _cur_G1_strong_roots_dur_ms, recent_avg_time_for_G1_strong_ms(),
ysr@777 1639 evac_ms, recent_avg_time_for_evac_ms(),
ysr@777 1640 scan_rs_time,
ysr@777 1641 recent_avg_time_for_pauses_ms() -
ysr@777 1642 recent_avg_time_for_G1_strong_ms(),
ysr@777 1643 rs_size);
ysr@777 1644
ysr@777 1645 gclog_or_tty->print_cr(" Used at start: " SIZE_FORMAT"K"
ysr@777 1646 " At end " SIZE_FORMAT "K\n"
ysr@777 1647 " garbage : " SIZE_FORMAT "K"
ysr@777 1648 " of " SIZE_FORMAT "K\n"
ysr@777 1649 " survival : %6.2f%% (%6.2f%% avg)",
ysr@777 1650 _cur_collection_pause_used_at_start_bytes/K,
ysr@777 1651 _g1->used()/K, freed_bytes/K,
ysr@777 1652 _collection_set_bytes_used_before/K,
ysr@777 1653 survival_fraction*100.0,
ysr@777 1654 recent_avg_survival_fraction()*100.0);
ysr@777 1655 gclog_or_tty->print_cr(" Recent %% gc pause time: %6.2f",
ysr@777 1656 recent_avg_pause_time_ratio() * 100.0);
ysr@777 1657 }
ysr@777 1658
ysr@777 1659 double other_time_ms = elapsed_ms;
ysr@777 1660
ysr@777 1661 if (!abandoned) {
ysr@777 1662 if (_satb_drain_time_set)
ysr@777 1663 other_time_ms -= _cur_satb_drain_time_ms;
ysr@777 1664
ysr@777 1665 if (parallel)
ysr@777 1666 other_time_ms -= _cur_collection_par_time_ms + _cur_clear_ct_time_ms;
ysr@777 1667 else
ysr@777 1668 other_time_ms -=
ysr@777 1669 update_rs_time +
ysr@777 1670 ext_root_scan_time + mark_stack_scan_time + scan_only_time +
ysr@777 1671 scan_rs_time + obj_copy_time;
ysr@777 1672 }
ysr@777 1673
ysr@777 1674 if (PrintGCDetails) {
ysr@777 1675 gclog_or_tty->print_cr("%s%s, %1.8lf secs]",
apetrusenko@1112 1676 abandoned ? " (abandoned)" : "",
ysr@777 1677 (last_pause_included_initial_mark) ? " (initial-mark)" : "",
ysr@777 1678 elapsed_ms / 1000.0);
ysr@777 1679
ysr@777 1680 if (!abandoned) {
apetrusenko@1112 1681 if (_satb_drain_time_set) {
ysr@777 1682 print_stats(1, "SATB Drain Time", _cur_satb_drain_time_ms);
apetrusenko@1112 1683 }
apetrusenko@1112 1684 if (_last_satb_drain_processed_buffers >= 0) {
ysr@777 1685 print_stats(2, "Processed Buffers", _last_satb_drain_processed_buffers);
apetrusenko@1112 1686 }
apetrusenko@1112 1687 if (parallel) {
apetrusenko@1112 1688 print_stats(1, "Parallel Time", _cur_collection_par_time_ms);
apetrusenko@1112 1689 print_par_stats(2, "Update RS (Start)", _par_last_update_rs_start_times_ms, false);
apetrusenko@1112 1690 print_par_stats(2, "Update RS", _par_last_update_rs_times_ms);
iveresov@1229 1691 print_par_buffers(3, "Processed Buffers",
iveresov@1229 1692 _par_last_update_rs_processed_buffers, true);
ysr@777 1693 print_par_stats(2, "Ext Root Scanning", _par_last_ext_root_scan_times_ms);
ysr@777 1694 print_par_stats(2, "Mark Stack Scanning", _par_last_mark_stack_scan_times_ms);
ysr@777 1695 print_par_stats(2, "Scan-Only Scanning", _par_last_scan_only_times_ms);
ysr@777 1696 print_par_buffers(3, "Scan-Only Regions",
ysr@777 1697 _par_last_scan_only_regions_scanned, true);
ysr@777 1698 print_par_stats(2, "Scan RS", _par_last_scan_rs_times_ms);
ysr@777 1699 print_par_stats(2, "Object Copy", _par_last_obj_copy_times_ms);
ysr@777 1700 print_par_stats(2, "Termination", _par_last_termination_times_ms);
ysr@777 1701 print_stats(2, "Other", parallel_other_time);
ysr@777 1702 print_stats(1, "Clear CT", _cur_clear_ct_time_ms);
apetrusenko@1112 1703 } else {
apetrusenko@1112 1704 print_stats(1, "Update RS", update_rs_time);
iveresov@1229 1705 print_stats(2, "Processed Buffers",
iveresov@1229 1706 (int)update_rs_processed_buffers);
ysr@777 1707 print_stats(1, "Ext Root Scanning", ext_root_scan_time);
ysr@777 1708 print_stats(1, "Mark Stack Scanning", mark_stack_scan_time);
ysr@777 1709 print_stats(1, "Scan-Only Scanning", scan_only_time);
ysr@777 1710 print_stats(1, "Scan RS", scan_rs_time);
ysr@777 1711 print_stats(1, "Object Copying", obj_copy_time);
ysr@777 1712 }
ysr@777 1713 }
johnc@1325 1714 #ifndef PRODUCT
johnc@1325 1715 print_stats(1, "Cur Clear CC", _cur_clear_cc_time_ms);
johnc@1325 1716 print_stats(1, "Cum Clear CC", _cum_clear_cc_time_ms);
johnc@1325 1717 print_stats(1, "Min Clear CC", _min_clear_cc_time_ms);
johnc@1325 1718 print_stats(1, "Max Clear CC", _max_clear_cc_time_ms);
johnc@1325 1719 if (_num_cc_clears > 0) {
johnc@1325 1720 print_stats(1, "Avg Clear CC", _cum_clear_cc_time_ms / ((double)_num_cc_clears));
johnc@1325 1721 }
johnc@1325 1722 #endif
ysr@777 1723 print_stats(1, "Other", other_time_ms);
ysr@777 1724 for (int i = 0; i < _aux_num; ++i) {
ysr@777 1725 if (_cur_aux_times_set[i]) {
ysr@777 1726 char buffer[96];
ysr@777 1727 sprintf(buffer, "Aux%d", i);
ysr@777 1728 print_stats(1, buffer, _cur_aux_times_ms[i]);
ysr@777 1729 }
ysr@777 1730 }
ysr@777 1731 }
ysr@777 1732 if (PrintGCDetails)
ysr@777 1733 gclog_or_tty->print(" [");
ysr@777 1734 if (PrintGC || PrintGCDetails)
ysr@777 1735 _g1->print_size_transition(gclog_or_tty,
ysr@777 1736 _cur_collection_pause_used_at_start_bytes,
ysr@777 1737 _g1->used(), _g1->capacity());
ysr@777 1738 if (PrintGCDetails)
ysr@777 1739 gclog_or_tty->print_cr("]");
ysr@777 1740
ysr@777 1741 _all_pause_times_ms->add(elapsed_ms);
tonyp@1083 1742 if (update_stats) {
tonyp@1083 1743 summary->record_total_time_ms(elapsed_ms);
tonyp@1083 1744 summary->record_other_time_ms(other_time_ms);
tonyp@1083 1745 }
ysr@777 1746 for (int i = 0; i < _aux_num; ++i)
ysr@777 1747 if (_cur_aux_times_set[i])
ysr@777 1748 _all_aux_times_ms[i].add(_cur_aux_times_ms[i]);
ysr@777 1749
ysr@777 1750 // Reset marks-between-pauses counter.
ysr@777 1751 _n_marks_since_last_pause = 0;
ysr@777 1752
ysr@777 1753 // Update the efficiency-since-mark vars.
ysr@777 1754 double proc_ms = elapsed_ms * (double) _parallel_gc_threads;
ysr@777 1755 if (elapsed_ms < MIN_TIMER_GRANULARITY) {
ysr@777 1756 // This usually happens due to the timer not having the required
ysr@777 1757 // granularity. Some Linuxes are the usual culprits.
ysr@777 1758 // We'll just set it to something (arbitrarily) small.
ysr@777 1759 proc_ms = 1.0;
ysr@777 1760 }
ysr@777 1761 double cur_efficiency = (double) freed_bytes / proc_ms;
ysr@777 1762
ysr@777 1763 bool new_in_marking_window = _in_marking_window;
ysr@777 1764 bool new_in_marking_window_im = false;
tonyp@1794 1765 if (during_initial_mark_pause()) {
ysr@777 1766 new_in_marking_window = true;
ysr@777 1767 new_in_marking_window_im = true;
ysr@777 1768 }
ysr@777 1769
ysr@777 1770 if (in_young_gc_mode()) {
ysr@777 1771 if (_last_full_young_gc) {
ysr@777 1772 set_full_young_gcs(false);
ysr@777 1773 _last_full_young_gc = false;
ysr@777 1774 }
ysr@777 1775
ysr@777 1776 if ( !_last_young_gc_full ) {
ysr@777 1777 if ( _should_revert_to_full_young_gcs ||
ysr@777 1778 _known_garbage_ratio < 0.05 ||
ysr@777 1779 (adaptive_young_list_length() &&
ysr@777 1780 (get_gc_eff_factor() * cur_efficiency < predict_young_gc_eff())) ) {
ysr@777 1781 set_full_young_gcs(true);
ysr@777 1782 }
ysr@777 1783 }
ysr@777 1784 _should_revert_to_full_young_gcs = false;
ysr@777 1785
ysr@777 1786 if (_last_young_gc_full && !_during_marking)
ysr@777 1787 _young_gc_eff_seq->add(cur_efficiency);
ysr@777 1788 }
ysr@777 1789
ysr@777 1790 _short_lived_surv_rate_group->start_adding_regions();
ysr@777 1791 // do that for any other surv rate groupsx
ysr@777 1792
ysr@777 1793 // <NEW PREDICTION>
ysr@777 1794
apetrusenko@1112 1795 if (update_stats) {
ysr@777 1796 double pause_time_ms = elapsed_ms;
ysr@777 1797
ysr@777 1798 size_t diff = 0;
ysr@777 1799 if (_max_pending_cards >= _pending_cards)
ysr@777 1800 diff = _max_pending_cards - _pending_cards;
ysr@777 1801 _pending_card_diff_seq->add((double) diff);
ysr@777 1802
ysr@777 1803 double cost_per_card_ms = 0.0;
ysr@777 1804 if (_pending_cards > 0) {
ysr@777 1805 cost_per_card_ms = update_rs_time / (double) _pending_cards;
ysr@777 1806 _cost_per_card_ms_seq->add(cost_per_card_ms);
ysr@777 1807 }
ysr@777 1808
ysr@777 1809 double cost_per_scan_only_region_ms = 0.0;
ysr@777 1810 if (scan_only_regions_scanned > 0.0) {
ysr@777 1811 cost_per_scan_only_region_ms =
ysr@777 1812 scan_only_time / scan_only_regions_scanned;
ysr@777 1813 if (_in_marking_window_im)
ysr@777 1814 _cost_per_scan_only_region_ms_during_cm_seq->add(cost_per_scan_only_region_ms);
ysr@777 1815 else
ysr@777 1816 _cost_per_scan_only_region_ms_seq->add(cost_per_scan_only_region_ms);
ysr@777 1817 }
ysr@777 1818
ysr@777 1819 size_t cards_scanned = _g1->cards_scanned();
ysr@777 1820
ysr@777 1821 double cost_per_entry_ms = 0.0;
ysr@777 1822 if (cards_scanned > 10) {
ysr@777 1823 cost_per_entry_ms = scan_rs_time / (double) cards_scanned;
ysr@777 1824 if (_last_young_gc_full)
ysr@777 1825 _cost_per_entry_ms_seq->add(cost_per_entry_ms);
ysr@777 1826 else
ysr@777 1827 _partially_young_cost_per_entry_ms_seq->add(cost_per_entry_ms);
ysr@777 1828 }
ysr@777 1829
ysr@777 1830 if (_max_rs_lengths > 0) {
ysr@777 1831 double cards_per_entry_ratio =
ysr@777 1832 (double) cards_scanned / (double) _max_rs_lengths;
ysr@777 1833 if (_last_young_gc_full)
ysr@777 1834 _fully_young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
ysr@777 1835 else
ysr@777 1836 _partially_young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
ysr@777 1837 }
ysr@777 1838
ysr@777 1839 size_t rs_length_diff = _max_rs_lengths - _recorded_rs_lengths;
ysr@777 1840 if (rs_length_diff >= 0)
ysr@777 1841 _rs_length_diff_seq->add((double) rs_length_diff);
ysr@777 1842
ysr@777 1843 size_t copied_bytes = surviving_bytes;
ysr@777 1844 double cost_per_byte_ms = 0.0;
ysr@777 1845 if (copied_bytes > 0) {
ysr@777 1846 cost_per_byte_ms = obj_copy_time / (double) copied_bytes;
ysr@777 1847 if (_in_marking_window)
ysr@777 1848 _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms);
ysr@777 1849 else
ysr@777 1850 _cost_per_byte_ms_seq->add(cost_per_byte_ms);
ysr@777 1851 }
ysr@777 1852
ysr@777 1853 double all_other_time_ms = pause_time_ms -
ysr@777 1854 (update_rs_time + scan_only_time + scan_rs_time + obj_copy_time +
ysr@777 1855 _mark_closure_time_ms + termination_time);
ysr@777 1856
ysr@777 1857 double young_other_time_ms = 0.0;
ysr@777 1858 if (_recorded_young_regions > 0) {
ysr@777 1859 young_other_time_ms =
ysr@777 1860 _recorded_young_cset_choice_time_ms +
ysr@777 1861 _recorded_young_free_cset_time_ms;
ysr@777 1862 _young_other_cost_per_region_ms_seq->add(young_other_time_ms /
ysr@777 1863 (double) _recorded_young_regions);
ysr@777 1864 }
ysr@777 1865 double non_young_other_time_ms = 0.0;
ysr@777 1866 if (_recorded_non_young_regions > 0) {
ysr@777 1867 non_young_other_time_ms =
ysr@777 1868 _recorded_non_young_cset_choice_time_ms +
ysr@777 1869 _recorded_non_young_free_cset_time_ms;
ysr@777 1870
ysr@777 1871 _non_young_other_cost_per_region_ms_seq->add(non_young_other_time_ms /
ysr@777 1872 (double) _recorded_non_young_regions);
ysr@777 1873 }
ysr@777 1874
ysr@777 1875 double constant_other_time_ms = all_other_time_ms -
ysr@777 1876 (young_other_time_ms + non_young_other_time_ms);
ysr@777 1877 _constant_other_time_ms_seq->add(constant_other_time_ms);
ysr@777 1878
ysr@777 1879 double survival_ratio = 0.0;
ysr@777 1880 if (_bytes_in_collection_set_before_gc > 0) {
ysr@777 1881 survival_ratio = (double) bytes_in_to_space_during_gc() /
ysr@777 1882 (double) _bytes_in_collection_set_before_gc;
ysr@777 1883 }
ysr@777 1884
ysr@777 1885 _pending_cards_seq->add((double) _pending_cards);
ysr@777 1886 _scanned_cards_seq->add((double) cards_scanned);
ysr@777 1887 _rs_lengths_seq->add((double) _max_rs_lengths);
ysr@777 1888
ysr@777 1889 double expensive_region_limit_ms =
johnc@1186 1890 (double) MaxGCPauseMillis - predict_constant_other_time_ms();
ysr@777 1891 if (expensive_region_limit_ms < 0.0) {
ysr@777 1892 // this means that the other time was predicted to be longer than
ysr@777 1893 // than the max pause time
johnc@1186 1894 expensive_region_limit_ms = (double) MaxGCPauseMillis;
ysr@777 1895 }
ysr@777 1896 _expensive_region_limit_ms = expensive_region_limit_ms;
ysr@777 1897
ysr@777 1898 if (PREDICTIONS_VERBOSE) {
ysr@777 1899 gclog_or_tty->print_cr("");
ysr@777 1900 gclog_or_tty->print_cr("PREDICTIONS %1.4lf %d "
ysr@777 1901 "REGIONS %d %d %d %d "
ysr@777 1902 "PENDING_CARDS %d %d "
ysr@777 1903 "CARDS_SCANNED %d %d "
ysr@777 1904 "RS_LENGTHS %d %d "
ysr@777 1905 "SCAN_ONLY_SCAN %1.6lf %1.6lf "
ysr@777 1906 "RS_UPDATE %1.6lf %1.6lf RS_SCAN %1.6lf %1.6lf "
ysr@777 1907 "SURVIVAL_RATIO %1.6lf %1.6lf "
ysr@777 1908 "OBJECT_COPY %1.6lf %1.6lf OTHER_CONSTANT %1.6lf %1.6lf "
ysr@777 1909 "OTHER_YOUNG %1.6lf %1.6lf "
ysr@777 1910 "OTHER_NON_YOUNG %1.6lf %1.6lf "
ysr@777 1911 "VTIME_DIFF %1.6lf TERMINATION %1.6lf "
ysr@777 1912 "ELAPSED %1.6lf %1.6lf ",
ysr@777 1913 _cur_collection_start_sec,
ysr@777 1914 (!_last_young_gc_full) ? 2 :
ysr@777 1915 (last_pause_included_initial_mark) ? 1 : 0,
ysr@777 1916 _recorded_region_num,
ysr@777 1917 _recorded_young_regions,
ysr@777 1918 _recorded_scan_only_regions,
ysr@777 1919 _recorded_non_young_regions,
ysr@777 1920 _predicted_pending_cards, _pending_cards,
ysr@777 1921 _predicted_cards_scanned, cards_scanned,
ysr@777 1922 _predicted_rs_lengths, _max_rs_lengths,
ysr@777 1923 _predicted_scan_only_scan_time_ms, scan_only_time,
ysr@777 1924 _predicted_rs_update_time_ms, update_rs_time,
ysr@777 1925 _predicted_rs_scan_time_ms, scan_rs_time,
ysr@777 1926 _predicted_survival_ratio, survival_ratio,
ysr@777 1927 _predicted_object_copy_time_ms, obj_copy_time,
ysr@777 1928 _predicted_constant_other_time_ms, constant_other_time_ms,
ysr@777 1929 _predicted_young_other_time_ms, young_other_time_ms,
ysr@777 1930 _predicted_non_young_other_time_ms,
ysr@777 1931 non_young_other_time_ms,
ysr@777 1932 _vtime_diff_ms, termination_time,
ysr@777 1933 _predicted_pause_time_ms, elapsed_ms);
ysr@777 1934 }
ysr@777 1935
ysr@777 1936 if (G1PolicyVerbose > 0) {
ysr@777 1937 gclog_or_tty->print_cr("Pause Time, predicted: %1.4lfms (predicted %s), actual: %1.4lfms",
ysr@777 1938 _predicted_pause_time_ms,
ysr@777 1939 (_within_target) ? "within" : "outside",
ysr@777 1940 elapsed_ms);
ysr@777 1941 }
ysr@777 1942
ysr@777 1943 }
ysr@777 1944
ysr@777 1945 _in_marking_window = new_in_marking_window;
ysr@777 1946 _in_marking_window_im = new_in_marking_window_im;
ysr@777 1947 _free_regions_at_end_of_collection = _g1->free_regions();
ysr@777 1948 _scan_only_regions_at_end_of_collection = _g1->young_list_length();
ysr@777 1949 calculate_young_list_min_length();
ysr@777 1950 calculate_young_list_target_config();
ysr@777 1951
iveresov@1546 1952 // Note that _mmu_tracker->max_gc_time() returns the time in seconds.
tonyp@1717 1953 double update_rs_time_goal_ms = _mmu_tracker->max_gc_time() * MILLIUNITS * G1RSetUpdatingPauseTimePercent / 100.0;
iveresov@1546 1954 adjust_concurrent_refinement(update_rs_time, update_rs_processed_buffers, update_rs_time_goal_ms);
iveresov@1546 1955
ysr@777 1956 // </NEW PREDICTION>
ysr@777 1957
ysr@777 1958 _target_pause_time_ms = -1.0;
ysr@777 1959 }
ysr@777 1960
ysr@777 1961 // <NEW PREDICTION>
ysr@777 1962
iveresov@1546 1963 void G1CollectorPolicy::adjust_concurrent_refinement(double update_rs_time,
iveresov@1546 1964 double update_rs_processed_buffers,
iveresov@1546 1965 double goal_ms) {
iveresov@1546 1966 DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
iveresov@1546 1967 ConcurrentG1Refine *cg1r = G1CollectedHeap::heap()->concurrent_g1_refine();
iveresov@1546 1968
tonyp@1717 1969 if (G1UseAdaptiveConcRefinement) {
iveresov@1546 1970 const int k_gy = 3, k_gr = 6;
iveresov@1546 1971 const double inc_k = 1.1, dec_k = 0.9;
iveresov@1546 1972
iveresov@1546 1973 int g = cg1r->green_zone();
iveresov@1546 1974 if (update_rs_time > goal_ms) {
iveresov@1546 1975 g = (int)(g * dec_k); // Can become 0, that's OK. That would mean a mutator-only processing.
iveresov@1546 1976 } else {
iveresov@1546 1977 if (update_rs_time < goal_ms && update_rs_processed_buffers > g) {
iveresov@1546 1978 g = (int)MAX2(g * inc_k, g + 1.0);
iveresov@1546 1979 }
iveresov@1546 1980 }
iveresov@1546 1981 // Change the refinement threads params
iveresov@1546 1982 cg1r->set_green_zone(g);
iveresov@1546 1983 cg1r->set_yellow_zone(g * k_gy);
iveresov@1546 1984 cg1r->set_red_zone(g * k_gr);
iveresov@1546 1985 cg1r->reinitialize_threads();
iveresov@1546 1986
iveresov@1546 1987 int processing_threshold_delta = MAX2((int)(cg1r->green_zone() * sigma()), 1);
iveresov@1546 1988 int processing_threshold = MIN2(cg1r->green_zone() + processing_threshold_delta,
iveresov@1546 1989 cg1r->yellow_zone());
iveresov@1546 1990 // Change the barrier params
iveresov@1546 1991 dcqs.set_process_completed_threshold(processing_threshold);
iveresov@1546 1992 dcqs.set_max_completed_queue(cg1r->red_zone());
iveresov@1546 1993 }
iveresov@1546 1994
iveresov@1546 1995 int curr_queue_size = dcqs.completed_buffers_num();
iveresov@1546 1996 if (curr_queue_size >= cg1r->yellow_zone()) {
iveresov@1546 1997 dcqs.set_completed_queue_padding(curr_queue_size);
iveresov@1546 1998 } else {
iveresov@1546 1999 dcqs.set_completed_queue_padding(0);
iveresov@1546 2000 }
iveresov@1546 2001 dcqs.notify_if_necessary();
iveresov@1546 2002 }
iveresov@1546 2003
ysr@777 2004 double
ysr@777 2005 G1CollectorPolicy::
ysr@777 2006 predict_young_collection_elapsed_time_ms(size_t adjustment) {
ysr@777 2007 guarantee( adjustment == 0 || adjustment == 1, "invariant" );
ysr@777 2008
ysr@777 2009 G1CollectedHeap* g1h = G1CollectedHeap::heap();
ysr@777 2010 size_t young_num = g1h->young_list_length();
ysr@777 2011 if (young_num == 0)
ysr@777 2012 return 0.0;
ysr@777 2013
ysr@777 2014 young_num += adjustment;
ysr@777 2015 size_t pending_cards = predict_pending_cards();
ysr@777 2016 size_t rs_lengths = g1h->young_list_sampled_rs_lengths() +
ysr@777 2017 predict_rs_length_diff();
ysr@777 2018 size_t card_num;
ysr@777 2019 if (full_young_gcs())
ysr@777 2020 card_num = predict_young_card_num(rs_lengths);
ysr@777 2021 else
ysr@777 2022 card_num = predict_non_young_card_num(rs_lengths);
ysr@777 2023 size_t young_byte_size = young_num * HeapRegion::GrainBytes;
ysr@777 2024 double accum_yg_surv_rate =
ysr@777 2025 _short_lived_surv_rate_group->accum_surv_rate(adjustment);
ysr@777 2026
ysr@777 2027 size_t bytes_to_copy =
ysr@777 2028 (size_t) (accum_yg_surv_rate * (double) HeapRegion::GrainBytes);
ysr@777 2029
ysr@777 2030 return
ysr@777 2031 predict_rs_update_time_ms(pending_cards) +
ysr@777 2032 predict_rs_scan_time_ms(card_num) +
ysr@777 2033 predict_object_copy_time_ms(bytes_to_copy) +
ysr@777 2034 predict_young_other_time_ms(young_num) +
ysr@777 2035 predict_constant_other_time_ms();
ysr@777 2036 }
ysr@777 2037
ysr@777 2038 double
ysr@777 2039 G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards) {
ysr@777 2040 size_t rs_length = predict_rs_length_diff();
ysr@777 2041 size_t card_num;
ysr@777 2042 if (full_young_gcs())
ysr@777 2043 card_num = predict_young_card_num(rs_length);
ysr@777 2044 else
ysr@777 2045 card_num = predict_non_young_card_num(rs_length);
ysr@777 2046 return predict_base_elapsed_time_ms(pending_cards, card_num);
ysr@777 2047 }
ysr@777 2048
ysr@777 2049 double
ysr@777 2050 G1CollectorPolicy::predict_base_elapsed_time_ms(size_t pending_cards,
ysr@777 2051 size_t scanned_cards) {
ysr@777 2052 return
ysr@777 2053 predict_rs_update_time_ms(pending_cards) +
ysr@777 2054 predict_rs_scan_time_ms(scanned_cards) +
ysr@777 2055 predict_constant_other_time_ms();
ysr@777 2056 }
ysr@777 2057
ysr@777 2058 double
ysr@777 2059 G1CollectorPolicy::predict_region_elapsed_time_ms(HeapRegion* hr,
ysr@777 2060 bool young) {
ysr@777 2061 size_t rs_length = hr->rem_set()->occupied();
ysr@777 2062 size_t card_num;
ysr@777 2063 if (full_young_gcs())
ysr@777 2064 card_num = predict_young_card_num(rs_length);
ysr@777 2065 else
ysr@777 2066 card_num = predict_non_young_card_num(rs_length);
ysr@777 2067 size_t bytes_to_copy = predict_bytes_to_copy(hr);
ysr@777 2068
ysr@777 2069 double region_elapsed_time_ms =
ysr@777 2070 predict_rs_scan_time_ms(card_num) +
ysr@777 2071 predict_object_copy_time_ms(bytes_to_copy);
ysr@777 2072
ysr@777 2073 if (young)
ysr@777 2074 region_elapsed_time_ms += predict_young_other_time_ms(1);
ysr@777 2075 else
ysr@777 2076 region_elapsed_time_ms += predict_non_young_other_time_ms(1);
ysr@777 2077
ysr@777 2078 return region_elapsed_time_ms;
ysr@777 2079 }
ysr@777 2080
ysr@777 2081 size_t
ysr@777 2082 G1CollectorPolicy::predict_bytes_to_copy(HeapRegion* hr) {
ysr@777 2083 size_t bytes_to_copy;
ysr@777 2084 if (hr->is_marked())
ysr@777 2085 bytes_to_copy = hr->max_live_bytes();
ysr@777 2086 else {
ysr@777 2087 guarantee( hr->is_young() && hr->age_in_surv_rate_group() != -1,
ysr@777 2088 "invariant" );
ysr@777 2089 int age = hr->age_in_surv_rate_group();
apetrusenko@980 2090 double yg_surv_rate = predict_yg_surv_rate(age, hr->surv_rate_group());
ysr@777 2091 bytes_to_copy = (size_t) ((double) hr->used() * yg_surv_rate);
ysr@777 2092 }
ysr@777 2093
ysr@777 2094 return bytes_to_copy;
ysr@777 2095 }
ysr@777 2096
ysr@777 2097 void
ysr@777 2098 G1CollectorPolicy::start_recording_regions() {
ysr@777 2099 _recorded_rs_lengths = 0;
ysr@777 2100 _recorded_scan_only_regions = 0;
ysr@777 2101 _recorded_young_regions = 0;
ysr@777 2102 _recorded_non_young_regions = 0;
ysr@777 2103
ysr@777 2104 #if PREDICTIONS_VERBOSE
ysr@777 2105 _predicted_rs_lengths = 0;
ysr@777 2106 _predicted_cards_scanned = 0;
ysr@777 2107
ysr@777 2108 _recorded_marked_bytes = 0;
ysr@777 2109 _recorded_young_bytes = 0;
ysr@777 2110 _predicted_bytes_to_copy = 0;
ysr@777 2111 #endif // PREDICTIONS_VERBOSE
ysr@777 2112 }
ysr@777 2113
ysr@777 2114 void
ysr@777 2115 G1CollectorPolicy::record_cset_region(HeapRegion* hr, bool young) {
ysr@777 2116 if (young) {
ysr@777 2117 ++_recorded_young_regions;
ysr@777 2118 } else {
ysr@777 2119 ++_recorded_non_young_regions;
ysr@777 2120 }
ysr@777 2121 #if PREDICTIONS_VERBOSE
ysr@777 2122 if (young) {
apetrusenko@980 2123 _recorded_young_bytes += hr->used();
ysr@777 2124 } else {
ysr@777 2125 _recorded_marked_bytes += hr->max_live_bytes();
ysr@777 2126 }
ysr@777 2127 _predicted_bytes_to_copy += predict_bytes_to_copy(hr);
ysr@777 2128 #endif // PREDICTIONS_VERBOSE
ysr@777 2129
ysr@777 2130 size_t rs_length = hr->rem_set()->occupied();
ysr@777 2131 _recorded_rs_lengths += rs_length;
ysr@777 2132 }
ysr@777 2133
ysr@777 2134 void
ysr@777 2135 G1CollectorPolicy::record_scan_only_regions(size_t scan_only_length) {
ysr@777 2136 _recorded_scan_only_regions = scan_only_length;
ysr@777 2137 }
ysr@777 2138
ysr@777 2139 void
ysr@777 2140 G1CollectorPolicy::end_recording_regions() {
ysr@777 2141 #if PREDICTIONS_VERBOSE
ysr@777 2142 _predicted_pending_cards = predict_pending_cards();
ysr@777 2143 _predicted_rs_lengths = _recorded_rs_lengths + predict_rs_length_diff();
ysr@777 2144 if (full_young_gcs())
ysr@777 2145 _predicted_cards_scanned += predict_young_card_num(_predicted_rs_lengths);
ysr@777 2146 else
ysr@777 2147 _predicted_cards_scanned +=
ysr@777 2148 predict_non_young_card_num(_predicted_rs_lengths);
ysr@777 2149 _recorded_region_num = _recorded_young_regions + _recorded_non_young_regions;
ysr@777 2150
ysr@777 2151 _predicted_scan_only_scan_time_ms =
ysr@777 2152 predict_scan_only_time_ms(_recorded_scan_only_regions);
ysr@777 2153 _predicted_rs_update_time_ms =
ysr@777 2154 predict_rs_update_time_ms(_g1->pending_card_num());
ysr@777 2155 _predicted_rs_scan_time_ms =
ysr@777 2156 predict_rs_scan_time_ms(_predicted_cards_scanned);
ysr@777 2157 _predicted_object_copy_time_ms =
ysr@777 2158 predict_object_copy_time_ms(_predicted_bytes_to_copy);
ysr@777 2159 _predicted_constant_other_time_ms =
ysr@777 2160 predict_constant_other_time_ms();
ysr@777 2161 _predicted_young_other_time_ms =
ysr@777 2162 predict_young_other_time_ms(_recorded_young_regions);
ysr@777 2163 _predicted_non_young_other_time_ms =
ysr@777 2164 predict_non_young_other_time_ms(_recorded_non_young_regions);
ysr@777 2165
ysr@777 2166 _predicted_pause_time_ms =
ysr@777 2167 _predicted_scan_only_scan_time_ms +
ysr@777 2168 _predicted_rs_update_time_ms +
ysr@777 2169 _predicted_rs_scan_time_ms +
ysr@777 2170 _predicted_object_copy_time_ms +
ysr@777 2171 _predicted_constant_other_time_ms +
ysr@777 2172 _predicted_young_other_time_ms +
ysr@777 2173 _predicted_non_young_other_time_ms;
ysr@777 2174 #endif // PREDICTIONS_VERBOSE
ysr@777 2175 }
ysr@777 2176
ysr@777 2177 void G1CollectorPolicy::check_if_region_is_too_expensive(double
ysr@777 2178 predicted_time_ms) {
ysr@777 2179 // I don't think we need to do this when in young GC mode since
ysr@777 2180 // marking will be initiated next time we hit the soft limit anyway...
ysr@777 2181 if (predicted_time_ms > _expensive_region_limit_ms) {
ysr@777 2182 if (!in_young_gc_mode()) {
ysr@777 2183 set_full_young_gcs(true);
tonyp@1794 2184 // We might want to do something different here. However,
tonyp@1794 2185 // right now we don't support the non-generational G1 mode
tonyp@1794 2186 // (and in fact we are planning to remove the associated code,
tonyp@1794 2187 // see CR 6814390). So, let's leave it as is and this will be
tonyp@1794 2188 // removed some time in the future
tonyp@1794 2189 ShouldNotReachHere();
tonyp@1794 2190 set_during_initial_mark_pause();
ysr@777 2191 } else
ysr@777 2192 // no point in doing another partial one
ysr@777 2193 _should_revert_to_full_young_gcs = true;
ysr@777 2194 }
ysr@777 2195 }
ysr@777 2196
ysr@777 2197 // </NEW PREDICTION>
ysr@777 2198
ysr@777 2199
ysr@777 2200 void G1CollectorPolicy::update_recent_gc_times(double end_time_sec,
ysr@777 2201 double elapsed_ms) {
ysr@777 2202 _recent_gc_times_ms->add(elapsed_ms);
ysr@777 2203 _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec);
ysr@777 2204 _prev_collection_pause_end_ms = end_time_sec * 1000.0;
ysr@777 2205 }
ysr@777 2206
ysr@777 2207 double G1CollectorPolicy::recent_avg_time_for_pauses_ms() {
johnc@1186 2208 if (_recent_pause_times_ms->num() == 0) return (double) MaxGCPauseMillis;
ysr@777 2209 else return _recent_pause_times_ms->avg();
ysr@777 2210 }
ysr@777 2211
ysr@777 2212 double G1CollectorPolicy::recent_avg_time_for_CH_strong_ms() {
ysr@777 2213 if (_recent_CH_strong_roots_times_ms->num() == 0)
johnc@1186 2214 return (double)MaxGCPauseMillis/3.0;
ysr@777 2215 else return _recent_CH_strong_roots_times_ms->avg();
ysr@777 2216 }
ysr@777 2217
ysr@777 2218 double G1CollectorPolicy::recent_avg_time_for_G1_strong_ms() {
ysr@777 2219 if (_recent_G1_strong_roots_times_ms->num() == 0)
johnc@1186 2220 return (double)MaxGCPauseMillis/3.0;
ysr@777 2221 else return _recent_G1_strong_roots_times_ms->avg();
ysr@777 2222 }
ysr@777 2223
ysr@777 2224 double G1CollectorPolicy::recent_avg_time_for_evac_ms() {
johnc@1186 2225 if (_recent_evac_times_ms->num() == 0) return (double)MaxGCPauseMillis/3.0;
ysr@777 2226 else return _recent_evac_times_ms->avg();
ysr@777 2227 }
ysr@777 2228
ysr@777 2229 int G1CollectorPolicy::number_of_recent_gcs() {
ysr@777 2230 assert(_recent_CH_strong_roots_times_ms->num() ==
ysr@777 2231 _recent_G1_strong_roots_times_ms->num(), "Sequence out of sync");
ysr@777 2232 assert(_recent_G1_strong_roots_times_ms->num() ==
ysr@777 2233 _recent_evac_times_ms->num(), "Sequence out of sync");
ysr@777 2234 assert(_recent_evac_times_ms->num() ==
ysr@777 2235 _recent_pause_times_ms->num(), "Sequence out of sync");
ysr@777 2236 assert(_recent_pause_times_ms->num() ==
ysr@777 2237 _recent_CS_bytes_used_before->num(), "Sequence out of sync");
ysr@777 2238 assert(_recent_CS_bytes_used_before->num() ==
ysr@777 2239 _recent_CS_bytes_surviving->num(), "Sequence out of sync");
ysr@777 2240 return _recent_pause_times_ms->num();
ysr@777 2241 }
ysr@777 2242
ysr@777 2243 double G1CollectorPolicy::recent_avg_survival_fraction() {
ysr@777 2244 return recent_avg_survival_fraction_work(_recent_CS_bytes_surviving,
ysr@777 2245 _recent_CS_bytes_used_before);
ysr@777 2246 }
ysr@777 2247
ysr@777 2248 double G1CollectorPolicy::last_survival_fraction() {
ysr@777 2249 return last_survival_fraction_work(_recent_CS_bytes_surviving,
ysr@777 2250 _recent_CS_bytes_used_before);
ysr@777 2251 }
ysr@777 2252
ysr@777 2253 double
ysr@777 2254 G1CollectorPolicy::recent_avg_survival_fraction_work(TruncatedSeq* surviving,
ysr@777 2255 TruncatedSeq* before) {
ysr@777 2256 assert(surviving->num() == before->num(), "Sequence out of sync");
ysr@777 2257 if (before->sum() > 0.0) {
ysr@777 2258 double recent_survival_rate = surviving->sum() / before->sum();
ysr@777 2259 // We exempt parallel collection from this check because Alloc Buffer
ysr@777 2260 // fragmentation can produce negative collections.
ysr@777 2261 // Further, we're now always doing parallel collection. But I'm still
ysr@777 2262 // leaving this here as a placeholder for a more precise assertion later.
ysr@777 2263 // (DLD, 10/05.)
ysr@777 2264 assert((true || ParallelGCThreads > 0) ||
ysr@777 2265 _g1->evacuation_failed() ||
ysr@777 2266 recent_survival_rate <= 1.0, "Or bad frac");
ysr@777 2267 return recent_survival_rate;
ysr@777 2268 } else {
ysr@777 2269 return 1.0; // Be conservative.
ysr@777 2270 }
ysr@777 2271 }
ysr@777 2272
ysr@777 2273 double
ysr@777 2274 G1CollectorPolicy::last_survival_fraction_work(TruncatedSeq* surviving,
ysr@777 2275 TruncatedSeq* before) {
ysr@777 2276 assert(surviving->num() == before->num(), "Sequence out of sync");
ysr@777 2277 if (surviving->num() > 0 && before->last() > 0.0) {
ysr@777 2278 double last_survival_rate = surviving->last() / before->last();
ysr@777 2279 // We exempt parallel collection from this check because Alloc Buffer
ysr@777 2280 // fragmentation can produce negative collections.
ysr@777 2281 // Further, we're now always doing parallel collection. But I'm still
ysr@777 2282 // leaving this here as a placeholder for a more precise assertion later.
ysr@777 2283 // (DLD, 10/05.)
ysr@777 2284 assert((true || ParallelGCThreads > 0) ||
ysr@777 2285 last_survival_rate <= 1.0, "Or bad frac");
ysr@777 2286 return last_survival_rate;
ysr@777 2287 } else {
ysr@777 2288 return 1.0;
ysr@777 2289 }
ysr@777 2290 }
ysr@777 2291
ysr@777 2292 static const int survival_min_obs = 5;
ysr@777 2293 static double survival_min_obs_limits[] = { 0.9, 0.7, 0.5, 0.3, 0.1 };
ysr@777 2294 static const double min_survival_rate = 0.1;
ysr@777 2295
ysr@777 2296 double
ysr@777 2297 G1CollectorPolicy::conservative_avg_survival_fraction_work(double avg,
ysr@777 2298 double latest) {
ysr@777 2299 double res = avg;
ysr@777 2300 if (number_of_recent_gcs() < survival_min_obs) {
ysr@777 2301 res = MAX2(res, survival_min_obs_limits[number_of_recent_gcs()]);
ysr@777 2302 }
ysr@777 2303 res = MAX2(res, latest);
ysr@777 2304 res = MAX2(res, min_survival_rate);
ysr@777 2305 // In the parallel case, LAB fragmentation can produce "negative
ysr@777 2306 // collections"; so can evac failure. Cap at 1.0
ysr@777 2307 res = MIN2(res, 1.0);
ysr@777 2308 return res;
ysr@777 2309 }
ysr@777 2310
ysr@777 2311 size_t G1CollectorPolicy::expansion_amount() {
tonyp@1791 2312 if ((recent_avg_pause_time_ratio() * 100.0) > _gc_overhead_perc) {
johnc@1186 2313 // We will double the existing space, or take
johnc@1186 2314 // G1ExpandByPercentOfAvailable % of the available expansion
johnc@1186 2315 // space, whichever is smaller, bounded below by a minimum
johnc@1186 2316 // expansion (unless that's all that's left.)
ysr@777 2317 const size_t min_expand_bytes = 1*M;
ysr@777 2318 size_t reserved_bytes = _g1->g1_reserved_obj_bytes();
ysr@777 2319 size_t committed_bytes = _g1->capacity();
ysr@777 2320 size_t uncommitted_bytes = reserved_bytes - committed_bytes;
ysr@777 2321 size_t expand_bytes;
ysr@777 2322 size_t expand_bytes_via_pct =
johnc@1186 2323 uncommitted_bytes * G1ExpandByPercentOfAvailable / 100;
ysr@777 2324 expand_bytes = MIN2(expand_bytes_via_pct, committed_bytes);
ysr@777 2325 expand_bytes = MAX2(expand_bytes, min_expand_bytes);
ysr@777 2326 expand_bytes = MIN2(expand_bytes, uncommitted_bytes);
ysr@777 2327 if (G1PolicyVerbose > 1) {
ysr@777 2328 gclog_or_tty->print("Decided to expand: ratio = %5.2f, "
ysr@777 2329 "committed = %d%s, uncommited = %d%s, via pct = %d%s.\n"
ysr@777 2330 " Answer = %d.\n",
ysr@777 2331 recent_avg_pause_time_ratio(),
ysr@777 2332 byte_size_in_proper_unit(committed_bytes),
ysr@777 2333 proper_unit_for_byte_size(committed_bytes),
ysr@777 2334 byte_size_in_proper_unit(uncommitted_bytes),
ysr@777 2335 proper_unit_for_byte_size(uncommitted_bytes),
ysr@777 2336 byte_size_in_proper_unit(expand_bytes_via_pct),
ysr@777 2337 proper_unit_for_byte_size(expand_bytes_via_pct),
ysr@777 2338 byte_size_in_proper_unit(expand_bytes),
ysr@777 2339 proper_unit_for_byte_size(expand_bytes));
ysr@777 2340 }
ysr@777 2341 return expand_bytes;
ysr@777 2342 } else {
ysr@777 2343 return 0;
ysr@777 2344 }
ysr@777 2345 }
ysr@777 2346
ysr@777 2347 void G1CollectorPolicy::note_start_of_mark_thread() {
ysr@777 2348 _mark_thread_startup_sec = os::elapsedTime();
ysr@777 2349 }
ysr@777 2350
ysr@777 2351 class CountCSClosure: public HeapRegionClosure {
ysr@777 2352 G1CollectorPolicy* _g1_policy;
ysr@777 2353 public:
ysr@777 2354 CountCSClosure(G1CollectorPolicy* g1_policy) :
ysr@777 2355 _g1_policy(g1_policy) {}
ysr@777 2356 bool doHeapRegion(HeapRegion* r) {
ysr@777 2357 _g1_policy->_bytes_in_collection_set_before_gc += r->used();
ysr@777 2358 return false;
ysr@777 2359 }
ysr@777 2360 };
ysr@777 2361
ysr@777 2362 void G1CollectorPolicy::count_CS_bytes_used() {
ysr@777 2363 CountCSClosure cs_closure(this);
ysr@777 2364 _g1->collection_set_iterate(&cs_closure);
ysr@777 2365 }
ysr@777 2366
ysr@777 2367 static void print_indent(int level) {
ysr@777 2368 for (int j = 0; j < level+1; ++j)
ysr@777 2369 gclog_or_tty->print(" ");
ysr@777 2370 }
ysr@777 2371
ysr@777 2372 void G1CollectorPolicy::print_summary (int level,
ysr@777 2373 const char* str,
ysr@777 2374 NumberSeq* seq) const {
ysr@777 2375 double sum = seq->sum();
ysr@777 2376 print_indent(level);
ysr@777 2377 gclog_or_tty->print_cr("%-24s = %8.2lf s (avg = %8.2lf ms)",
ysr@777 2378 str, sum / 1000.0, seq->avg());
ysr@777 2379 }
ysr@777 2380
ysr@777 2381 void G1CollectorPolicy::print_summary_sd (int level,
ysr@777 2382 const char* str,
ysr@777 2383 NumberSeq* seq) const {
ysr@777 2384 print_summary(level, str, seq);
ysr@777 2385 print_indent(level + 5);
ysr@777 2386 gclog_or_tty->print_cr("(num = %5d, std dev = %8.2lf ms, max = %8.2lf ms)",
ysr@777 2387 seq->num(), seq->sd(), seq->maximum());
ysr@777 2388 }
ysr@777 2389
ysr@777 2390 void G1CollectorPolicy::check_other_times(int level,
ysr@777 2391 NumberSeq* other_times_ms,
ysr@777 2392 NumberSeq* calc_other_times_ms) const {
ysr@777 2393 bool should_print = false;
ysr@777 2394
ysr@777 2395 double max_sum = MAX2(fabs(other_times_ms->sum()),
ysr@777 2396 fabs(calc_other_times_ms->sum()));
ysr@777 2397 double min_sum = MIN2(fabs(other_times_ms->sum()),
ysr@777 2398 fabs(calc_other_times_ms->sum()));
ysr@777 2399 double sum_ratio = max_sum / min_sum;
ysr@777 2400 if (sum_ratio > 1.1) {
ysr@777 2401 should_print = true;
ysr@777 2402 print_indent(level + 1);
ysr@777 2403 gclog_or_tty->print_cr("## CALCULATED OTHER SUM DOESN'T MATCH RECORDED ###");
ysr@777 2404 }
ysr@777 2405
ysr@777 2406 double max_avg = MAX2(fabs(other_times_ms->avg()),
ysr@777 2407 fabs(calc_other_times_ms->avg()));
ysr@777 2408 double min_avg = MIN2(fabs(other_times_ms->avg()),
ysr@777 2409 fabs(calc_other_times_ms->avg()));
ysr@777 2410 double avg_ratio = max_avg / min_avg;
ysr@777 2411 if (avg_ratio > 1.1) {
ysr@777 2412 should_print = true;
ysr@777 2413 print_indent(level + 1);
ysr@777 2414 gclog_or_tty->print_cr("## CALCULATED OTHER AVG DOESN'T MATCH RECORDED ###");
ysr@777 2415 }
ysr@777 2416
ysr@777 2417 if (other_times_ms->sum() < -0.01) {
ysr@777 2418 print_indent(level + 1);
ysr@777 2419 gclog_or_tty->print_cr("## RECORDED OTHER SUM IS NEGATIVE ###");
ysr@777 2420 }
ysr@777 2421
ysr@777 2422 if (other_times_ms->avg() < -0.01) {
ysr@777 2423 print_indent(level + 1);
ysr@777 2424 gclog_or_tty->print_cr("## RECORDED OTHER AVG IS NEGATIVE ###");
ysr@777 2425 }
ysr@777 2426
ysr@777 2427 if (calc_other_times_ms->sum() < -0.01) {
ysr@777 2428 should_print = true;
ysr@777 2429 print_indent(level + 1);
ysr@777 2430 gclog_or_tty->print_cr("## CALCULATED OTHER SUM IS NEGATIVE ###");
ysr@777 2431 }
ysr@777 2432
ysr@777 2433 if (calc_other_times_ms->avg() < -0.01) {
ysr@777 2434 should_print = true;
ysr@777 2435 print_indent(level + 1);
ysr@777 2436 gclog_or_tty->print_cr("## CALCULATED OTHER AVG IS NEGATIVE ###");
ysr@777 2437 }
ysr@777 2438
ysr@777 2439 if (should_print)
ysr@777 2440 print_summary(level, "Other(Calc)", calc_other_times_ms);
ysr@777 2441 }
ysr@777 2442
ysr@777 2443 void G1CollectorPolicy::print_summary(PauseSummary* summary) const {
ysr@777 2444 bool parallel = ParallelGCThreads > 0;
ysr@777 2445 MainBodySummary* body_summary = summary->main_body_summary();
ysr@777 2446 if (summary->get_total_seq()->num() > 0) {
apetrusenko@1112 2447 print_summary_sd(0, "Evacuation Pauses", summary->get_total_seq());
ysr@777 2448 if (body_summary != NULL) {
ysr@777 2449 print_summary(1, "SATB Drain", body_summary->get_satb_drain_seq());
ysr@777 2450 if (parallel) {
ysr@777 2451 print_summary(1, "Parallel Time", body_summary->get_parallel_seq());
ysr@777 2452 print_summary(2, "Update RS", body_summary->get_update_rs_seq());
ysr@777 2453 print_summary(2, "Ext Root Scanning",
ysr@777 2454 body_summary->get_ext_root_scan_seq());
ysr@777 2455 print_summary(2, "Mark Stack Scanning",
ysr@777 2456 body_summary->get_mark_stack_scan_seq());
ysr@777 2457 print_summary(2, "Scan-Only Scanning",
ysr@777 2458 body_summary->get_scan_only_seq());
ysr@777 2459 print_summary(2, "Scan RS", body_summary->get_scan_rs_seq());
ysr@777 2460 print_summary(2, "Object Copy", body_summary->get_obj_copy_seq());
ysr@777 2461 print_summary(2, "Termination", body_summary->get_termination_seq());
ysr@777 2462 print_summary(2, "Other", body_summary->get_parallel_other_seq());
ysr@777 2463 {
ysr@777 2464 NumberSeq* other_parts[] = {
ysr@777 2465 body_summary->get_update_rs_seq(),
ysr@777 2466 body_summary->get_ext_root_scan_seq(),
ysr@777 2467 body_summary->get_mark_stack_scan_seq(),
ysr@777 2468 body_summary->get_scan_only_seq(),
ysr@777 2469 body_summary->get_scan_rs_seq(),
ysr@777 2470 body_summary->get_obj_copy_seq(),
ysr@777 2471 body_summary->get_termination_seq()
ysr@777 2472 };
ysr@777 2473 NumberSeq calc_other_times_ms(body_summary->get_parallel_seq(),
ysr@777 2474 7, other_parts);
ysr@777 2475 check_other_times(2, body_summary->get_parallel_other_seq(),
ysr@777 2476 &calc_other_times_ms);
ysr@777 2477 }
ysr@777 2478 print_summary(1, "Mark Closure", body_summary->get_mark_closure_seq());
ysr@777 2479 print_summary(1, "Clear CT", body_summary->get_clear_ct_seq());
ysr@777 2480 } else {
ysr@777 2481 print_summary(1, "Update RS", body_summary->get_update_rs_seq());
ysr@777 2482 print_summary(1, "Ext Root Scanning",
ysr@777 2483 body_summary->get_ext_root_scan_seq());
ysr@777 2484 print_summary(1, "Mark Stack Scanning",
ysr@777 2485 body_summary->get_mark_stack_scan_seq());
ysr@777 2486 print_summary(1, "Scan-Only Scanning",
ysr@777 2487 body_summary->get_scan_only_seq());
ysr@777 2488 print_summary(1, "Scan RS", body_summary->get_scan_rs_seq());
ysr@777 2489 print_summary(1, "Object Copy", body_summary->get_obj_copy_seq());
ysr@777 2490 }
ysr@777 2491 }
ysr@777 2492 print_summary(1, "Other", summary->get_other_seq());
ysr@777 2493 {
ysr@777 2494 NumberSeq calc_other_times_ms;
ysr@777 2495 if (body_summary != NULL) {
ysr@777 2496 // not abandoned
ysr@777 2497 if (parallel) {
ysr@777 2498 // parallel
ysr@777 2499 NumberSeq* other_parts[] = {
ysr@777 2500 body_summary->get_satb_drain_seq(),
ysr@777 2501 body_summary->get_parallel_seq(),
ysr@777 2502 body_summary->get_clear_ct_seq()
ysr@777 2503 };
apetrusenko@1112 2504 calc_other_times_ms = NumberSeq(summary->get_total_seq(),
apetrusenko@1112 2505 3, other_parts);
ysr@777 2506 } else {
ysr@777 2507 // serial
ysr@777 2508 NumberSeq* other_parts[] = {
ysr@777 2509 body_summary->get_satb_drain_seq(),
ysr@777 2510 body_summary->get_update_rs_seq(),
ysr@777 2511 body_summary->get_ext_root_scan_seq(),
ysr@777 2512 body_summary->get_mark_stack_scan_seq(),
ysr@777 2513 body_summary->get_scan_only_seq(),
ysr@777 2514 body_summary->get_scan_rs_seq(),
ysr@777 2515 body_summary->get_obj_copy_seq()
ysr@777 2516 };
ysr@777 2517 calc_other_times_ms = NumberSeq(summary->get_total_seq(),
apetrusenko@1112 2518 7, other_parts);
ysr@777 2519 }
ysr@777 2520 } else {
ysr@777 2521 // abandoned
apetrusenko@1112 2522 calc_other_times_ms = NumberSeq();
ysr@777 2523 }
ysr@777 2524 check_other_times(1, summary->get_other_seq(), &calc_other_times_ms);
ysr@777 2525 }
ysr@777 2526 } else {
ysr@777 2527 print_indent(0);
ysr@777 2528 gclog_or_tty->print_cr("none");
ysr@777 2529 }
ysr@777 2530 gclog_or_tty->print_cr("");
ysr@777 2531 }
ysr@777 2532
ysr@777 2533 void
apetrusenko@1112 2534 G1CollectorPolicy::print_abandoned_summary(PauseSummary* summary) const {
ysr@777 2535 bool printed = false;
apetrusenko@1112 2536 if (summary->get_total_seq()->num() > 0) {
ysr@777 2537 printed = true;
apetrusenko@1112 2538 print_summary(summary);
ysr@777 2539 }
ysr@777 2540 if (!printed) {
ysr@777 2541 print_indent(0);
ysr@777 2542 gclog_or_tty->print_cr("none");
ysr@777 2543 gclog_or_tty->print_cr("");
ysr@777 2544 }
ysr@777 2545 }
ysr@777 2546
ysr@777 2547 void G1CollectorPolicy::print_tracing_info() const {
ysr@777 2548 if (TraceGen0Time) {
ysr@777 2549 gclog_or_tty->print_cr("ALL PAUSES");
ysr@777 2550 print_summary_sd(0, "Total", _all_pause_times_ms);
ysr@777 2551 gclog_or_tty->print_cr("");
ysr@777 2552 gclog_or_tty->print_cr("");
ysr@777 2553 gclog_or_tty->print_cr(" Full Young GC Pauses: %8d", _full_young_pause_num);
ysr@777 2554 gclog_or_tty->print_cr(" Partial Young GC Pauses: %8d", _partial_young_pause_num);
ysr@777 2555 gclog_or_tty->print_cr("");
ysr@777 2556
apetrusenko@1112 2557 gclog_or_tty->print_cr("EVACUATION PAUSES");
apetrusenko@1112 2558 print_summary(_summary);
ysr@777 2559
ysr@777 2560 gclog_or_tty->print_cr("ABANDONED PAUSES");
apetrusenko@1112 2561 print_abandoned_summary(_abandoned_summary);
ysr@777 2562
ysr@777 2563 gclog_or_tty->print_cr("MISC");
ysr@777 2564 print_summary_sd(0, "Stop World", _all_stop_world_times_ms);
ysr@777 2565 print_summary_sd(0, "Yields", _all_yield_times_ms);
ysr@777 2566 for (int i = 0; i < _aux_num; ++i) {
ysr@777 2567 if (_all_aux_times_ms[i].num() > 0) {
ysr@777 2568 char buffer[96];
ysr@777 2569 sprintf(buffer, "Aux%d", i);
ysr@777 2570 print_summary_sd(0, buffer, &_all_aux_times_ms[i]);
ysr@777 2571 }
ysr@777 2572 }
ysr@777 2573
ysr@777 2574 size_t all_region_num = _region_num_young + _region_num_tenured;
ysr@777 2575 gclog_or_tty->print_cr(" New Regions %8d, Young %8d (%6.2lf%%), "
ysr@777 2576 "Tenured %8d (%6.2lf%%)",
ysr@777 2577 all_region_num,
ysr@777 2578 _region_num_young,
ysr@777 2579 (double) _region_num_young / (double) all_region_num * 100.0,
ysr@777 2580 _region_num_tenured,
ysr@777 2581 (double) _region_num_tenured / (double) all_region_num * 100.0);
ysr@777 2582 }
ysr@777 2583 if (TraceGen1Time) {
ysr@777 2584 if (_all_full_gc_times_ms->num() > 0) {
ysr@777 2585 gclog_or_tty->print("\n%4d full_gcs: total time = %8.2f s",
ysr@777 2586 _all_full_gc_times_ms->num(),
ysr@777 2587 _all_full_gc_times_ms->sum() / 1000.0);
ysr@777 2588 gclog_or_tty->print_cr(" (avg = %8.2fms).", _all_full_gc_times_ms->avg());
ysr@777 2589 gclog_or_tty->print_cr(" [std. dev = %8.2f ms, max = %8.2f ms]",
ysr@777 2590 _all_full_gc_times_ms->sd(),
ysr@777 2591 _all_full_gc_times_ms->maximum());
ysr@777 2592 }
ysr@777 2593 }
ysr@777 2594 }
ysr@777 2595
ysr@777 2596 void G1CollectorPolicy::print_yg_surv_rate_info() const {
ysr@777 2597 #ifndef PRODUCT
ysr@777 2598 _short_lived_surv_rate_group->print_surv_rate_summary();
ysr@777 2599 // add this call for any other surv rate groups
ysr@777 2600 #endif // PRODUCT
ysr@777 2601 }
ysr@777 2602
ysr@777 2603 bool
ysr@777 2604 G1CollectorPolicy::should_add_next_region_to_young_list() {
ysr@777 2605 assert(in_young_gc_mode(), "should be in young GC mode");
ysr@777 2606 bool ret;
ysr@777 2607 size_t young_list_length = _g1->young_list_length();
apetrusenko@980 2608 size_t young_list_max_length = _young_list_target_length;
apetrusenko@980 2609 if (G1FixedEdenSize) {
apetrusenko@980 2610 young_list_max_length -= _max_survivor_regions;
apetrusenko@980 2611 }
apetrusenko@980 2612 if (young_list_length < young_list_max_length) {
ysr@777 2613 ret = true;
ysr@777 2614 ++_region_num_young;
ysr@777 2615 } else {
ysr@777 2616 ret = false;
ysr@777 2617 ++_region_num_tenured;
ysr@777 2618 }
ysr@777 2619
ysr@777 2620 return ret;
ysr@777 2621 }
ysr@777 2622
ysr@777 2623 #ifndef PRODUCT
ysr@777 2624 // for debugging, bit of a hack...
ysr@777 2625 static char*
ysr@777 2626 region_num_to_mbs(int length) {
ysr@777 2627 static char buffer[64];
ysr@777 2628 double bytes = (double) (length * HeapRegion::GrainBytes);
ysr@777 2629 double mbs = bytes / (double) (1024 * 1024);
ysr@777 2630 sprintf(buffer, "%7.2lfMB", mbs);
ysr@777 2631 return buffer;
ysr@777 2632 }
ysr@777 2633 #endif // PRODUCT
ysr@777 2634
apetrusenko@980 2635 size_t G1CollectorPolicy::max_regions(int purpose) {
ysr@777 2636 switch (purpose) {
ysr@777 2637 case GCAllocForSurvived:
apetrusenko@980 2638 return _max_survivor_regions;
ysr@777 2639 case GCAllocForTenured:
apetrusenko@980 2640 return REGIONS_UNLIMITED;
ysr@777 2641 default:
apetrusenko@980 2642 ShouldNotReachHere();
apetrusenko@980 2643 return REGIONS_UNLIMITED;
ysr@777 2644 };
ysr@777 2645 }
ysr@777 2646
apetrusenko@980 2647 // Calculates survivor space parameters.
apetrusenko@980 2648 void G1CollectorPolicy::calculate_survivors_policy()
apetrusenko@980 2649 {
apetrusenko@980 2650 if (G1FixedSurvivorSpaceSize == 0) {
apetrusenko@980 2651 _max_survivor_regions = _young_list_target_length / SurvivorRatio;
apetrusenko@980 2652 } else {
apetrusenko@982 2653 _max_survivor_regions = G1FixedSurvivorSpaceSize / HeapRegion::GrainBytes;
apetrusenko@980 2654 }
apetrusenko@980 2655
apetrusenko@980 2656 if (G1FixedTenuringThreshold) {
apetrusenko@980 2657 _tenuring_threshold = MaxTenuringThreshold;
apetrusenko@980 2658 } else {
apetrusenko@980 2659 _tenuring_threshold = _survivors_age_table.compute_tenuring_threshold(
apetrusenko@980 2660 HeapRegion::GrainWords * _max_survivor_regions);
apetrusenko@980 2661 }
apetrusenko@980 2662 }
apetrusenko@980 2663
ysr@777 2664 bool
ysr@777 2665 G1CollectorPolicy_BestRegionsFirst::should_do_collection_pause(size_t
ysr@777 2666 word_size) {
ysr@777 2667 assert(_g1->regions_accounted_for(), "Region leakage!");
ysr@777 2668 double max_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
ysr@777 2669
ysr@777 2670 size_t young_list_length = _g1->young_list_length();
apetrusenko@980 2671 size_t young_list_max_length = _young_list_target_length;
apetrusenko@980 2672 if (G1FixedEdenSize) {
apetrusenko@980 2673 young_list_max_length -= _max_survivor_regions;
apetrusenko@980 2674 }
apetrusenko@980 2675 bool reached_target_length = young_list_length >= young_list_max_length;
ysr@777 2676
ysr@777 2677 if (in_young_gc_mode()) {
ysr@777 2678 if (reached_target_length) {
ysr@777 2679 assert( young_list_length > 0 && _g1->young_list_length() > 0,
ysr@777 2680 "invariant" );
ysr@777 2681 _target_pause_time_ms = max_pause_time_ms;
ysr@777 2682 return true;
ysr@777 2683 }
ysr@777 2684 } else {
ysr@777 2685 guarantee( false, "should not reach here" );
ysr@777 2686 }
ysr@777 2687
ysr@777 2688 return false;
ysr@777 2689 }
ysr@777 2690
ysr@777 2691 #ifndef PRODUCT
ysr@777 2692 class HRSortIndexIsOKClosure: public HeapRegionClosure {
ysr@777 2693 CollectionSetChooser* _chooser;
ysr@777 2694 public:
ysr@777 2695 HRSortIndexIsOKClosure(CollectionSetChooser* chooser) :
ysr@777 2696 _chooser(chooser) {}
ysr@777 2697
ysr@777 2698 bool doHeapRegion(HeapRegion* r) {
ysr@777 2699 if (!r->continuesHumongous()) {
ysr@777 2700 assert(_chooser->regionProperlyOrdered(r), "Ought to be.");
ysr@777 2701 }
ysr@777 2702 return false;
ysr@777 2703 }
ysr@777 2704 };
ysr@777 2705
ysr@777 2706 bool G1CollectorPolicy_BestRegionsFirst::assertMarkedBytesDataOK() {
ysr@777 2707 HRSortIndexIsOKClosure cl(_collectionSetChooser);
ysr@777 2708 _g1->heap_region_iterate(&cl);
ysr@777 2709 return true;
ysr@777 2710 }
ysr@777 2711 #endif
ysr@777 2712
ysr@777 2713 void
tonyp@1794 2714 G1CollectorPolicy::decide_on_conc_mark_initiation() {
tonyp@1794 2715 // We are about to decide on whether this pause will be an
tonyp@1794 2716 // initial-mark pause.
tonyp@1794 2717
tonyp@1794 2718 // First, during_initial_mark_pause() should not be already set. We
tonyp@1794 2719 // will set it here if we have to. However, it should be cleared by
tonyp@1794 2720 // the end of the pause (it's only set for the duration of an
tonyp@1794 2721 // initial-mark pause).
tonyp@1794 2722 assert(!during_initial_mark_pause(), "pre-condition");
tonyp@1794 2723
tonyp@1794 2724 if (initiate_conc_mark_if_possible()) {
tonyp@1794 2725 // We had noticed on a previous pause that the heap occupancy has
tonyp@1794 2726 // gone over the initiating threshold and we should start a
tonyp@1794 2727 // concurrent marking cycle. So we might initiate one.
tonyp@1794 2728
tonyp@1794 2729 bool during_cycle = _g1->concurrent_mark()->cmThread()->during_cycle();
tonyp@1794 2730 if (!during_cycle) {
tonyp@1794 2731 // The concurrent marking thread is not "during a cycle", i.e.,
tonyp@1794 2732 // it has completed the last one. So we can go ahead and
tonyp@1794 2733 // initiate a new cycle.
tonyp@1794 2734
tonyp@1794 2735 set_during_initial_mark_pause();
tonyp@1794 2736
tonyp@1794 2737 // And we can now clear initiate_conc_mark_if_possible() as
tonyp@1794 2738 // we've already acted on it.
tonyp@1794 2739 clear_initiate_conc_mark_if_possible();
tonyp@1794 2740 } else {
tonyp@1794 2741 // The concurrent marking thread is still finishing up the
tonyp@1794 2742 // previous cycle. If we start one right now the two cycles
tonyp@1794 2743 // overlap. In particular, the concurrent marking thread might
tonyp@1794 2744 // be in the process of clearing the next marking bitmap (which
tonyp@1794 2745 // we will use for the next cycle if we start one). Starting a
tonyp@1794 2746 // cycle now will be bad given that parts of the marking
tonyp@1794 2747 // information might get cleared by the marking thread. And we
tonyp@1794 2748 // cannot wait for the marking thread to finish the cycle as it
tonyp@1794 2749 // periodically yields while clearing the next marking bitmap
tonyp@1794 2750 // and, if it's in a yield point, it's waiting for us to
tonyp@1794 2751 // finish. So, at this point we will not start a cycle and we'll
tonyp@1794 2752 // let the concurrent marking thread complete the last one.
tonyp@1794 2753 }
tonyp@1794 2754 }
tonyp@1794 2755 }
tonyp@1794 2756
tonyp@1794 2757 void
ysr@777 2758 G1CollectorPolicy_BestRegionsFirst::
ysr@777 2759 record_collection_pause_start(double start_time_sec, size_t start_used) {
ysr@777 2760 G1CollectorPolicy::record_collection_pause_start(start_time_sec, start_used);
ysr@777 2761 }
ysr@777 2762
ysr@777 2763 class NextNonCSElemFinder: public HeapRegionClosure {
ysr@777 2764 HeapRegion* _res;
ysr@777 2765 public:
ysr@777 2766 NextNonCSElemFinder(): _res(NULL) {}
ysr@777 2767 bool doHeapRegion(HeapRegion* r) {
ysr@777 2768 if (!r->in_collection_set()) {
ysr@777 2769 _res = r;
ysr@777 2770 return true;
ysr@777 2771 } else {
ysr@777 2772 return false;
ysr@777 2773 }
ysr@777 2774 }
ysr@777 2775 HeapRegion* res() { return _res; }
ysr@777 2776 };
ysr@777 2777
ysr@777 2778 class KnownGarbageClosure: public HeapRegionClosure {
ysr@777 2779 CollectionSetChooser* _hrSorted;
ysr@777 2780
ysr@777 2781 public:
ysr@777 2782 KnownGarbageClosure(CollectionSetChooser* hrSorted) :
ysr@777 2783 _hrSorted(hrSorted)
ysr@777 2784 {}
ysr@777 2785
ysr@777 2786 bool doHeapRegion(HeapRegion* r) {
ysr@777 2787 // We only include humongous regions in collection
ysr@777 2788 // sets when concurrent mark shows that their contained object is
ysr@777 2789 // unreachable.
ysr@777 2790
ysr@777 2791 // Do we have any marking information for this region?
ysr@777 2792 if (r->is_marked()) {
ysr@777 2793 // We don't include humongous regions in collection
ysr@777 2794 // sets because we collect them immediately at the end of a marking
ysr@777 2795 // cycle. We also don't include young regions because we *must*
ysr@777 2796 // include them in the next collection pause.
ysr@777 2797 if (!r->isHumongous() && !r->is_young()) {
ysr@777 2798 _hrSorted->addMarkedHeapRegion(r);
ysr@777 2799 }
ysr@777 2800 }
ysr@777 2801 return false;
ysr@777 2802 }
ysr@777 2803 };
ysr@777 2804
ysr@777 2805 class ParKnownGarbageHRClosure: public HeapRegionClosure {
ysr@777 2806 CollectionSetChooser* _hrSorted;
ysr@777 2807 jint _marked_regions_added;
ysr@777 2808 jint _chunk_size;
ysr@777 2809 jint _cur_chunk_idx;
ysr@777 2810 jint _cur_chunk_end; // Cur chunk [_cur_chunk_idx, _cur_chunk_end)
ysr@777 2811 int _worker;
ysr@777 2812 int _invokes;
ysr@777 2813
ysr@777 2814 void get_new_chunk() {
ysr@777 2815 _cur_chunk_idx = _hrSorted->getParMarkedHeapRegionChunk(_chunk_size);
ysr@777 2816 _cur_chunk_end = _cur_chunk_idx + _chunk_size;
ysr@777 2817 }
ysr@777 2818 void add_region(HeapRegion* r) {
ysr@777 2819 if (_cur_chunk_idx == _cur_chunk_end) {
ysr@777 2820 get_new_chunk();
ysr@777 2821 }
ysr@777 2822 assert(_cur_chunk_idx < _cur_chunk_end, "postcondition");
ysr@777 2823 _hrSorted->setMarkedHeapRegion(_cur_chunk_idx, r);
ysr@777 2824 _marked_regions_added++;
ysr@777 2825 _cur_chunk_idx++;
ysr@777 2826 }
ysr@777 2827
ysr@777 2828 public:
ysr@777 2829 ParKnownGarbageHRClosure(CollectionSetChooser* hrSorted,
ysr@777 2830 jint chunk_size,
ysr@777 2831 int worker) :
ysr@777 2832 _hrSorted(hrSorted), _chunk_size(chunk_size), _worker(worker),
ysr@777 2833 _marked_regions_added(0), _cur_chunk_idx(0), _cur_chunk_end(0),
ysr@777 2834 _invokes(0)
ysr@777 2835 {}
ysr@777 2836
ysr@777 2837 bool doHeapRegion(HeapRegion* r) {
ysr@777 2838 // We only include humongous regions in collection
ysr@777 2839 // sets when concurrent mark shows that their contained object is
ysr@777 2840 // unreachable.
ysr@777 2841 _invokes++;
ysr@777 2842
ysr@777 2843 // Do we have any marking information for this region?
ysr@777 2844 if (r->is_marked()) {
ysr@777 2845 // We don't include humongous regions in collection
ysr@777 2846 // sets because we collect them immediately at the end of a marking
ysr@777 2847 // cycle.
ysr@777 2848 // We also do not include young regions in collection sets
ysr@777 2849 if (!r->isHumongous() && !r->is_young()) {
ysr@777 2850 add_region(r);
ysr@777 2851 }
ysr@777 2852 }
ysr@777 2853 return false;
ysr@777 2854 }
ysr@777 2855 jint marked_regions_added() { return _marked_regions_added; }
ysr@777 2856 int invokes() { return _invokes; }
ysr@777 2857 };
ysr@777 2858
ysr@777 2859 class ParKnownGarbageTask: public AbstractGangTask {
ysr@777 2860 CollectionSetChooser* _hrSorted;
ysr@777 2861 jint _chunk_size;
ysr@777 2862 G1CollectedHeap* _g1;
ysr@777 2863 public:
ysr@777 2864 ParKnownGarbageTask(CollectionSetChooser* hrSorted, jint chunk_size) :
ysr@777 2865 AbstractGangTask("ParKnownGarbageTask"),
ysr@777 2866 _hrSorted(hrSorted), _chunk_size(chunk_size),
ysr@777 2867 _g1(G1CollectedHeap::heap())
ysr@777 2868 {}
ysr@777 2869
ysr@777 2870 void work(int i) {
ysr@777 2871 ParKnownGarbageHRClosure parKnownGarbageCl(_hrSorted, _chunk_size, i);
ysr@777 2872 // Back to zero for the claim value.
tonyp@790 2873 _g1->heap_region_par_iterate_chunked(&parKnownGarbageCl, i,
tonyp@790 2874 HeapRegion::InitialClaimValue);
ysr@777 2875 jint regions_added = parKnownGarbageCl.marked_regions_added();
ysr@777 2876 _hrSorted->incNumMarkedHeapRegions(regions_added);
ysr@777 2877 if (G1PrintParCleanupStats) {
ysr@777 2878 gclog_or_tty->print(" Thread %d called %d times, added %d regions to list.\n",
ysr@777 2879 i, parKnownGarbageCl.invokes(), regions_added);
ysr@777 2880 }
ysr@777 2881 }
ysr@777 2882 };
ysr@777 2883
ysr@777 2884 void
ysr@777 2885 G1CollectorPolicy_BestRegionsFirst::
ysr@777 2886 record_concurrent_mark_cleanup_end(size_t freed_bytes,
ysr@777 2887 size_t max_live_bytes) {
ysr@777 2888 double start;
ysr@777 2889 if (G1PrintParCleanupStats) start = os::elapsedTime();
ysr@777 2890 record_concurrent_mark_cleanup_end_work1(freed_bytes, max_live_bytes);
ysr@777 2891
ysr@777 2892 _collectionSetChooser->clearMarkedHeapRegions();
ysr@777 2893 double clear_marked_end;
ysr@777 2894 if (G1PrintParCleanupStats) {
ysr@777 2895 clear_marked_end = os::elapsedTime();
ysr@777 2896 gclog_or_tty->print_cr(" clear marked regions + work1: %8.3f ms.",
ysr@777 2897 (clear_marked_end - start)*1000.0);
ysr@777 2898 }
ysr@777 2899 if (ParallelGCThreads > 0) {
ysr@777 2900 const size_t OverpartitionFactor = 4;
ysr@777 2901 const size_t MinChunkSize = 8;
ysr@777 2902 const size_t ChunkSize =
ysr@777 2903 MAX2(_g1->n_regions() / (ParallelGCThreads * OverpartitionFactor),
ysr@777 2904 MinChunkSize);
ysr@777 2905 _collectionSetChooser->prepareForAddMarkedHeapRegionsPar(_g1->n_regions(),
ysr@777 2906 ChunkSize);
ysr@777 2907 ParKnownGarbageTask parKnownGarbageTask(_collectionSetChooser,
ysr@777 2908 (int) ChunkSize);
ysr@777 2909 _g1->workers()->run_task(&parKnownGarbageTask);
tonyp@790 2910
tonyp@790 2911 assert(_g1->check_heap_region_claim_values(HeapRegion::InitialClaimValue),
tonyp@790 2912 "sanity check");
ysr@777 2913 } else {
ysr@777 2914 KnownGarbageClosure knownGarbagecl(_collectionSetChooser);
ysr@777 2915 _g1->heap_region_iterate(&knownGarbagecl);
ysr@777 2916 }
ysr@777 2917 double known_garbage_end;
ysr@777 2918 if (G1PrintParCleanupStats) {
ysr@777 2919 known_garbage_end = os::elapsedTime();
ysr@777 2920 gclog_or_tty->print_cr(" compute known garbage: %8.3f ms.",
ysr@777 2921 (known_garbage_end - clear_marked_end)*1000.0);
ysr@777 2922 }
ysr@777 2923 _collectionSetChooser->sortMarkedHeapRegions();
ysr@777 2924 double sort_end;
ysr@777 2925 if (G1PrintParCleanupStats) {
ysr@777 2926 sort_end = os::elapsedTime();
ysr@777 2927 gclog_or_tty->print_cr(" sorting: %8.3f ms.",
ysr@777 2928 (sort_end - known_garbage_end)*1000.0);
ysr@777 2929 }
ysr@777 2930
ysr@777 2931 record_concurrent_mark_cleanup_end_work2();
ysr@777 2932 double work2_end;
ysr@777 2933 if (G1PrintParCleanupStats) {
ysr@777 2934 work2_end = os::elapsedTime();
ysr@777 2935 gclog_or_tty->print_cr(" work2: %8.3f ms.",
ysr@777 2936 (work2_end - sort_end)*1000.0);
ysr@777 2937 }
ysr@777 2938 }
ysr@777 2939
ysr@777 2940 // Add the heap region to the collection set and return the conservative
ysr@777 2941 // estimate of the number of live bytes.
ysr@777 2942 void G1CollectorPolicy::
ysr@777 2943 add_to_collection_set(HeapRegion* hr) {
tonyp@1717 2944 if (G1PrintHeapRegions) {
ysr@777 2945 gclog_or_tty->print_cr("added region to cset %d:["PTR_FORMAT", "PTR_FORMAT"], "
ysr@777 2946 "top "PTR_FORMAT", young %s",
ysr@777 2947 hr->hrs_index(), hr->bottom(), hr->end(),
ysr@777 2948 hr->top(), (hr->is_young()) ? "YES" : "NO");
ysr@777 2949 }
ysr@777 2950
ysr@777 2951 if (_g1->mark_in_progress())
ysr@777 2952 _g1->concurrent_mark()->registerCSetRegion(hr);
ysr@777 2953
ysr@777 2954 assert(!hr->in_collection_set(),
ysr@777 2955 "should not already be in the CSet");
ysr@777 2956 hr->set_in_collection_set(true);
ysr@777 2957 hr->set_next_in_collection_set(_collection_set);
ysr@777 2958 _collection_set = hr;
ysr@777 2959 _collection_set_size++;
ysr@777 2960 _collection_set_bytes_used_before += hr->used();
tonyp@961 2961 _g1->register_region_with_in_cset_fast_test(hr);
ysr@777 2962 }
ysr@777 2963
ysr@777 2964 void
ysr@777 2965 G1CollectorPolicy_BestRegionsFirst::
apetrusenko@1112 2966 choose_collection_set() {
ysr@777 2967 double non_young_start_time_sec;
ysr@777 2968 start_recording_regions();
ysr@777 2969
ysr@1523 2970 guarantee(_target_pause_time_ms > -1.0
ysr@1523 2971 NOT_PRODUCT(|| Universe::heap()->gc_cause() == GCCause::_scavenge_alot),
apetrusenko@1112 2972 "_target_pause_time_ms should have been set!");
ysr@1523 2973 #ifndef PRODUCT
ysr@1523 2974 if (_target_pause_time_ms <= -1.0) {
ysr@1523 2975 assert(ScavengeALot && Universe::heap()->gc_cause() == GCCause::_scavenge_alot, "Error");
ysr@1523 2976 _target_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
ysr@1523 2977 }
ysr@1523 2978 #endif
apetrusenko@1112 2979 assert(_collection_set == NULL, "Precondition");
ysr@777 2980
ysr@777 2981 double base_time_ms = predict_base_elapsed_time_ms(_pending_cards);
ysr@777 2982 double predicted_pause_time_ms = base_time_ms;
ysr@777 2983
ysr@777 2984 double target_time_ms = _target_pause_time_ms;
ysr@777 2985 double time_remaining_ms = target_time_ms - base_time_ms;
ysr@777 2986
ysr@777 2987 // the 10% and 50% values are arbitrary...
ysr@777 2988 if (time_remaining_ms < 0.10*target_time_ms) {
ysr@777 2989 time_remaining_ms = 0.50 * target_time_ms;
ysr@777 2990 _within_target = false;
ysr@777 2991 } else {
ysr@777 2992 _within_target = true;
ysr@777 2993 }
ysr@777 2994
ysr@777 2995 // We figure out the number of bytes available for future to-space.
ysr@777 2996 // For new regions without marking information, we must assume the
ysr@777 2997 // worst-case of complete survival. If we have marking information for a
ysr@777 2998 // region, we can bound the amount of live data. We can add a number of
ysr@777 2999 // such regions, as long as the sum of the live data bounds does not
ysr@777 3000 // exceed the available evacuation space.
ysr@777 3001 size_t max_live_bytes = _g1->free_regions() * HeapRegion::GrainBytes;
ysr@777 3002
ysr@777 3003 size_t expansion_bytes =
ysr@777 3004 _g1->expansion_regions() * HeapRegion::GrainBytes;
ysr@777 3005
apetrusenko@1112 3006 _collection_set_bytes_used_before = 0;
apetrusenko@1112 3007 _collection_set_size = 0;
ysr@777 3008
ysr@777 3009 // Adjust for expansion and slop.
ysr@777 3010 max_live_bytes = max_live_bytes + expansion_bytes;
ysr@777 3011
apetrusenko@1112 3012 assert(_g1->regions_accounted_for(), "Region leakage!");
ysr@777 3013
ysr@777 3014 HeapRegion* hr;
ysr@777 3015 if (in_young_gc_mode()) {
ysr@777 3016 double young_start_time_sec = os::elapsedTime();
ysr@777 3017
ysr@777 3018 if (G1PolicyVerbose > 0) {
ysr@777 3019 gclog_or_tty->print_cr("Adding %d young regions to the CSet",
ysr@777 3020 _g1->young_list_length());
ysr@777 3021 }
ysr@777 3022 _young_cset_length = 0;
ysr@777 3023 _last_young_gc_full = full_young_gcs() ? true : false;
ysr@777 3024 if (_last_young_gc_full)
ysr@777 3025 ++_full_young_pause_num;
ysr@777 3026 else
ysr@777 3027 ++_partial_young_pause_num;
ysr@777 3028 hr = _g1->pop_region_from_young_list();
ysr@777 3029 while (hr != NULL) {
ysr@777 3030
ysr@777 3031 assert( hr->young_index_in_cset() == -1, "invariant" );
ysr@777 3032 assert( hr->age_in_surv_rate_group() != -1, "invariant" );
ysr@777 3033 hr->set_young_index_in_cset((int) _young_cset_length);
ysr@777 3034
ysr@777 3035 ++_young_cset_length;
ysr@777 3036 double predicted_time_ms = predict_region_elapsed_time_ms(hr, true);
ysr@777 3037 time_remaining_ms -= predicted_time_ms;
ysr@777 3038 predicted_pause_time_ms += predicted_time_ms;
apetrusenko@1112 3039 assert(!hr->in_collection_set(), "invariant");
apetrusenko@1112 3040 add_to_collection_set(hr);
apetrusenko@1112 3041 record_cset_region(hr, true);
ysr@777 3042 max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes);
ysr@777 3043 if (G1PolicyVerbose > 0) {
ysr@777 3044 gclog_or_tty->print_cr(" Added [" PTR_FORMAT ", " PTR_FORMAT") to CS.",
ysr@777 3045 hr->bottom(), hr->end());
ysr@777 3046 gclog_or_tty->print_cr(" (" SIZE_FORMAT " KB left in heap.)",
ysr@777 3047 max_live_bytes/K);
ysr@777 3048 }
ysr@777 3049 hr = _g1->pop_region_from_young_list();
ysr@777 3050 }
ysr@777 3051
ysr@777 3052 record_scan_only_regions(_g1->young_list_scan_only_length());
ysr@777 3053
ysr@777 3054 double young_end_time_sec = os::elapsedTime();
ysr@777 3055 _recorded_young_cset_choice_time_ms =
ysr@777 3056 (young_end_time_sec - young_start_time_sec) * 1000.0;
ysr@777 3057
ysr@777 3058 non_young_start_time_sec = os::elapsedTime();
ysr@777 3059
ysr@777 3060 if (_young_cset_length > 0 && _last_young_gc_full) {
ysr@777 3061 // don't bother adding more regions...
ysr@777 3062 goto choose_collection_set_end;
ysr@777 3063 }
ysr@777 3064 }
ysr@777 3065
ysr@777 3066 if (!in_young_gc_mode() || !full_young_gcs()) {
ysr@777 3067 bool should_continue = true;
ysr@777 3068 NumberSeq seq;
ysr@777 3069 double avg_prediction = 100000000000000000.0; // something very large
ysr@777 3070 do {
ysr@777 3071 hr = _collectionSetChooser->getNextMarkedRegion(time_remaining_ms,
ysr@777 3072 avg_prediction);
apetrusenko@1112 3073 if (hr != NULL) {
ysr@777 3074 double predicted_time_ms = predict_region_elapsed_time_ms(hr, false);
ysr@777 3075 time_remaining_ms -= predicted_time_ms;
ysr@777 3076 predicted_pause_time_ms += predicted_time_ms;
ysr@777 3077 add_to_collection_set(hr);
ysr@777 3078 record_cset_region(hr, false);
ysr@777 3079 max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes);
ysr@777 3080 if (G1PolicyVerbose > 0) {
ysr@777 3081 gclog_or_tty->print_cr(" (" SIZE_FORMAT " KB left in heap.)",
ysr@777 3082 max_live_bytes/K);
ysr@777 3083 }
ysr@777 3084 seq.add(predicted_time_ms);
ysr@777 3085 avg_prediction = seq.avg() + seq.sd();
ysr@777 3086 }
ysr@777 3087 should_continue =
ysr@777 3088 ( hr != NULL) &&
ysr@777 3089 ( (adaptive_young_list_length()) ? time_remaining_ms > 0.0
ysr@777 3090 : _collection_set_size < _young_list_fixed_length );
ysr@777 3091 } while (should_continue);
ysr@777 3092
ysr@777 3093 if (!adaptive_young_list_length() &&
ysr@777 3094 _collection_set_size < _young_list_fixed_length)
ysr@777 3095 _should_revert_to_full_young_gcs = true;
ysr@777 3096 }
ysr@777 3097
ysr@777 3098 choose_collection_set_end:
ysr@777 3099 count_CS_bytes_used();
ysr@777 3100
ysr@777 3101 end_recording_regions();
ysr@777 3102
ysr@777 3103 double non_young_end_time_sec = os::elapsedTime();
ysr@777 3104 _recorded_non_young_cset_choice_time_ms =
ysr@777 3105 (non_young_end_time_sec - non_young_start_time_sec) * 1000.0;
ysr@777 3106 }
ysr@777 3107
ysr@777 3108 void G1CollectorPolicy_BestRegionsFirst::record_full_collection_end() {
ysr@777 3109 G1CollectorPolicy::record_full_collection_end();
ysr@777 3110 _collectionSetChooser->updateAfterFullCollection();
ysr@777 3111 }
ysr@777 3112
ysr@777 3113 void G1CollectorPolicy_BestRegionsFirst::
ysr@777 3114 expand_if_possible(size_t numRegions) {
ysr@777 3115 size_t expansion_bytes = numRegions * HeapRegion::GrainBytes;
ysr@777 3116 _g1->expand(expansion_bytes);
ysr@777 3117 }
ysr@777 3118
ysr@777 3119 void G1CollectorPolicy_BestRegionsFirst::
apetrusenko@1112 3120 record_collection_pause_end(bool abandoned) {
apetrusenko@1112 3121 G1CollectorPolicy::record_collection_pause_end(abandoned);
ysr@777 3122 assert(assertMarkedBytesDataOK(), "Marked regions not OK at pause end.");
ysr@777 3123 }

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