1 /*
2 * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/g1/g1Analytics.hpp"
27 #include "gc/g1/g1Predictions.hpp"
28 #include "runtime/globals.hpp"
29 #include "runtime/os.hpp"
30 #include "utilities/debug.hpp"
31 #include "utilities/numberSeq.hpp"
32
33 // Different defaults for different number of GC threads
34 // They were chosen by running GCOld and SPECjbb on debris with different
35 // numbers of GC threads and choosing them based on the results
36
37 // all the same
38 static double rs_length_diff_defaults[] = {
39 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
40 };
41
42 static double cost_per_logged_card_ms_defaults[] = {
43 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015
44 };
45
46 // all the same
47 static double young_cards_per_entry_ratio_defaults[] = {
48 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
49 };
50
51 static double young_only_cost_per_remset_card_ms_defaults[] = {
52 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005
53 };
54
55 static double cost_per_byte_ms_defaults[] = {
56 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009
57 };
58
59 // these should be pretty consistent
60 static double constant_other_time_ms_defaults[] = {
61 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0
62 };
63
64
65 static double young_other_cost_per_region_ms_defaults[] = {
66 0.3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1
67 };
68
69 static double non_young_other_cost_per_region_ms_defaults[] = {
70 1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30
71 };
72
73 G1Analytics::G1Analytics(const G1Predictions* predictor) :
74 _predictor(predictor),
75 _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
76 _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
77 _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
78 _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
79 _prev_collection_pause_end_ms(0.0),
80 _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
81 _concurrent_refine_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
82 _logged_cards_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
83 _cost_per_logged_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
84 _cost_scan_hcc_seq(new TruncatedSeq(TruncatedSeqLength)),
85 _young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
86 _mixed_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
87 _young_only_cost_per_remset_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
88 _mixed_cost_per_remset_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
89 _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
90 _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
91 _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
92 _non_young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
93 _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
94 _rs_length_seq(new TruncatedSeq(TruncatedSeqLength)),
95 _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
96 _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)),
97 _recent_avg_pause_time_ratio(0.0),
98 _last_pause_time_ratio(0.0) {
99
100 // Seed sequences with initial values.
101 _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime());
102 _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0;
103
104 int index = MIN2(ParallelGCThreads - 1, 7u);
105
106 _rs_length_diff_seq->add(rs_length_diff_defaults[index]);
107 // Start with inverse of maximum STW cost.
108 _concurrent_refine_rate_ms_seq->add(1/cost_per_logged_card_ms_defaults[0]);
109 // Some applications have very low rates for logging cards.
110 _logged_cards_rate_ms_seq->add(0.0);
111 _cost_per_logged_card_ms_seq->add(cost_per_logged_card_ms_defaults[index]);
112 _cost_scan_hcc_seq->add(0.0);
113 _young_cards_per_entry_ratio_seq->add(young_cards_per_entry_ratio_defaults[index]);
114 _young_only_cost_per_remset_card_ms_seq->add(young_only_cost_per_remset_card_ms_defaults[index]);
115 _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]);
116 _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]);
117 _young_other_cost_per_region_ms_seq->add(young_other_cost_per_region_ms_defaults[index]);
118 _non_young_other_cost_per_region_ms_seq->add(non_young_other_cost_per_region_ms_defaults[index]);
119
120 // start conservatively (around 50ms is about right)
121 _concurrent_mark_remark_times_ms->add(0.05);
122 _concurrent_mark_cleanup_times_ms->add(0.20);
123 }
124
125 double G1Analytics::get_new_prediction(TruncatedSeq const* seq) const {
126 return _predictor->get_new_prediction(seq);
127 }
128
129 size_t G1Analytics::get_new_size_prediction(TruncatedSeq const* seq) const {
130 return (size_t)get_new_prediction(seq);
131 }
132
133 int G1Analytics::num_alloc_rate_ms() const {
134 return _alloc_rate_ms_seq->num();
135 }
136
137 void G1Analytics::report_concurrent_mark_remark_times_ms(double ms) {
138 _concurrent_mark_remark_times_ms->add(ms);
139 }
140
141 void G1Analytics::report_alloc_rate_ms(double alloc_rate) {
142 _alloc_rate_ms_seq->add(alloc_rate);
143 }
144
145 void G1Analytics::compute_pause_time_ratio(double interval_ms, double pause_time_ms) {
146 _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum() / interval_ms;
147 if (_recent_avg_pause_time_ratio < 0.0 ||
148 (_recent_avg_pause_time_ratio - 1.0 > 0.0)) {
149 // Clip ratio between 0.0 and 1.0, and continue. This will be fixed in
150 // CR 6902692 by redoing the manner in which the ratio is incrementally computed.
151 if (_recent_avg_pause_time_ratio < 0.0) {
152 _recent_avg_pause_time_ratio = 0.0;
153 } else {
154 assert(_recent_avg_pause_time_ratio - 1.0 > 0.0, "Ctl-point invariant");
155 _recent_avg_pause_time_ratio = 1.0;
156 }
157 }
158
159 // Compute the ratio of just this last pause time to the entire time range stored
160 // in the vectors. Comparing this pause to the entire range, rather than only the
161 // most recent interval, has the effect of smoothing over a possible transient 'burst'
162 // of more frequent pauses that don't really reflect a change in heap occupancy.
163 // This reduces the likelihood of a needless heap expansion being triggered.
164 _last_pause_time_ratio =
165 (pause_time_ms * _recent_prev_end_times_for_all_gcs_sec->num()) / interval_ms;
166 }
167
168 void G1Analytics::report_concurrent_refine_rate_ms(double cards_per_ms) {
169 _concurrent_refine_rate_ms_seq->add(cards_per_ms);
170 }
171
172 void G1Analytics::report_logged_cards_rate_ms(double cards_per_ms) {
173 _logged_cards_rate_ms_seq->add(cards_per_ms);
174 }
175
176 void G1Analytics::report_cost_per_logged_card_ms(double cost_per_logged_card_ms) {
177 _cost_per_logged_card_ms_seq->add(cost_per_logged_card_ms);
178 }
179
180 void G1Analytics::report_cost_scan_hcc(double cost_scan_hcc) {
181 _cost_scan_hcc_seq->add(cost_scan_hcc);
182 }
183
184 void G1Analytics::report_cost_per_remset_card_ms(double cost_per_remset_card_ms, bool for_young_gc) {
185 if (for_young_gc) {
186 _young_only_cost_per_remset_card_ms_seq->add(cost_per_remset_card_ms);
187 } else {
188 _mixed_cost_per_remset_card_ms_seq->add(cost_per_remset_card_ms);
189 }
190 }
191
192 void G1Analytics::report_cards_per_entry_ratio(double cards_per_entry_ratio, bool for_young_gc) {
193 if (for_young_gc) {
194 _young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
195 } else {
196 _mixed_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
197 }
198 }
199
200 void G1Analytics::report_rs_length_diff(double rs_length_diff) {
201 _rs_length_diff_seq->add(rs_length_diff);
202 }
203
204 void G1Analytics::report_cost_per_byte_ms(double cost_per_byte_ms, bool mark_or_rebuild_in_progress) {
205 if (mark_or_rebuild_in_progress) {
206 _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms);
207 } else {
208 _cost_per_byte_ms_seq->add(cost_per_byte_ms);
209 }
210 }
211
212 void G1Analytics::report_young_other_cost_per_region_ms(double other_cost_per_region_ms) {
213 _young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms);
214 }
215
216 void G1Analytics::report_non_young_other_cost_per_region_ms(double other_cost_per_region_ms) {
217 _non_young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms);
218 }
219
220 void G1Analytics::report_constant_other_time_ms(double constant_other_time_ms) {
221 _constant_other_time_ms_seq->add(constant_other_time_ms);
222 }
223
224 void G1Analytics::report_pending_cards(double pending_cards) {
225 _pending_cards_seq->add(pending_cards);
226 }
227
228 void G1Analytics::report_rs_length(double rs_length) {
229 _rs_length_seq->add(rs_length);
230 }
231
232 double G1Analytics::predict_alloc_rate_ms() const {
233 return get_new_prediction(_alloc_rate_ms_seq);
234 }
235
236 double G1Analytics::predict_concurrent_refine_rate_ms() const {
237 return get_new_prediction(_concurrent_refine_rate_ms_seq);
238 }
239
240 double G1Analytics::predict_logged_cards_rate_ms() const {
241 return get_new_prediction(_logged_cards_rate_ms_seq);
242 }
243
244 double G1Analytics::predict_cost_per_logged_card_ms() const {
245 return get_new_prediction(_cost_per_logged_card_ms_seq);
246 }
247
248 double G1Analytics::predict_scan_hcc_ms() const {
249 return get_new_prediction(_cost_scan_hcc_seq);
250 }
251
252 double G1Analytics::predict_rs_update_time_ms(size_t pending_cards) const {
253 return pending_cards * predict_cost_per_logged_card_ms() + predict_scan_hcc_ms();
254 }
255
256 double G1Analytics::predict_young_cards_per_entry_ratio() const {
257 return get_new_prediction(_young_cards_per_entry_ratio_seq);
258 }
259
260 double G1Analytics::predict_mixed_cards_per_entry_ratio() const {
261 if (_mixed_cards_per_entry_ratio_seq->num() < 2) {
262 return predict_young_cards_per_entry_ratio();
263 } else {
264 return get_new_prediction(_mixed_cards_per_entry_ratio_seq);
265 }
266 }
267
268 size_t G1Analytics::predict_card_num(size_t rs_length, bool for_young_gc) const {
269 if (for_young_gc) {
270 return (size_t) (rs_length * predict_young_cards_per_entry_ratio());
271 } else {
272 return (size_t) (rs_length * predict_mixed_cards_per_entry_ratio());
273 }
274 }
275
276 double G1Analytics::predict_rs_scan_time_ms(size_t card_num, bool for_young_gc) const {
277 if (for_young_gc) {
278 return card_num * get_new_prediction(_young_only_cost_per_remset_card_ms_seq);
279 } else {
280 return predict_mixed_rs_scan_time_ms(card_num);
281 }
282 }
283
284 double G1Analytics::predict_mixed_rs_scan_time_ms(size_t card_num) const {
285 if (_mixed_cost_per_remset_card_ms_seq->num() < 3) {
286 return card_num * get_new_prediction(_young_only_cost_per_remset_card_ms_seq);
287 } else {
288 return card_num * get_new_prediction(_mixed_cost_per_remset_card_ms_seq);
289 }
290 }
291
292 double G1Analytics::predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) const {
293 if (_cost_per_byte_ms_during_cm_seq->num() < 3) {
294 return (1.1 * bytes_to_copy) * get_new_prediction(_cost_per_byte_ms_seq);
295 } else {
296 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_during_cm_seq);
297 }
298 }
299
300 double G1Analytics::predict_object_copy_time_ms(size_t bytes_to_copy, bool during_concurrent_mark) const {
301 if (during_concurrent_mark) {
302 return predict_object_copy_time_ms_during_cm(bytes_to_copy);
303 } else {
304 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_seq);
305 }
306 }
307
308 double G1Analytics::predict_cost_per_byte_ms() const {
309 return get_new_prediction(_cost_per_byte_ms_seq);
310 }
311
312 double G1Analytics::predict_constant_other_time_ms() const {
313 return get_new_prediction(_constant_other_time_ms_seq);
314 }
315
316 double G1Analytics::predict_young_other_time_ms(size_t young_num) const {
317 return young_num * get_new_prediction(_young_other_cost_per_region_ms_seq);
318 }
319
320 double G1Analytics::predict_non_young_other_time_ms(size_t non_young_num) const {
321 return non_young_num * get_new_prediction(_non_young_other_cost_per_region_ms_seq);
322 }
323
324 double G1Analytics::predict_remark_time_ms() const {
325 return get_new_prediction(_concurrent_mark_remark_times_ms);
326 }
327
328 double G1Analytics::predict_cleanup_time_ms() const {
329 return get_new_prediction(_concurrent_mark_cleanup_times_ms);
330 }
331
332 size_t G1Analytics::predict_rs_length() const {
333 return get_new_size_prediction(_rs_length_seq) + get_new_prediction(_rs_length_diff_seq);
334 }
335
336 size_t G1Analytics::predict_pending_cards() const {
337 return get_new_size_prediction(_pending_cards_seq);
338 }
339
340 double G1Analytics::last_known_gc_end_time_sec() const {
341 return _recent_prev_end_times_for_all_gcs_sec->oldest();
342 }
343
344 void G1Analytics::update_recent_gc_times(double end_time_sec,
345 double pause_time_ms) {
346 _recent_gc_times_ms->add(pause_time_ms);
347 _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec);
348 _prev_collection_pause_end_ms = end_time_sec * 1000.0;
349 }
350
351 void G1Analytics::report_concurrent_mark_cleanup_times_ms(double ms) {
352 _concurrent_mark_cleanup_times_ms->add(ms);
353 }