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/globalDefinitions.hpp"
32 #include "utilities/numberSeq.hpp"
33
34 // Different defaults for different number of GC threads
35 // They were chosen by running GCOld and SPECjbb on debris with different
36 // numbers of GC threads and choosing them based on the results
37
38 // all the same
39 static double rs_length_diff_defaults[] = {
40 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
41 };
42
43 static double cost_per_logged_card_ms_defaults[] = {
44 0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015
45 };
46
47 // all the same
48 static double young_cards_per_entry_ratio_defaults[] = {
49 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
50 };
51
52 static double young_only_cost_per_remset_card_ms_defaults[] = {
53 0.015, 0.01, 0.01, 0.008, 0.008, 0.0055, 0.0055, 0.005
54 };
55
56 static double cost_per_byte_ms_defaults[] = {
57 0.00006, 0.00003, 0.00003, 0.000015, 0.000015, 0.00001, 0.00001, 0.000009
58 };
59
60 // these should be pretty consistent
61 static double constant_other_time_ms_defaults[] = {
62 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0
63 };
64
65
66 static double young_other_cost_per_region_ms_defaults[] = {
67 0.3, 0.2, 0.2, 0.15, 0.15, 0.12, 0.12, 0.1
68 };
69
70 static double non_young_other_cost_per_region_ms_defaults[] = {
71 1.0, 0.7, 0.7, 0.5, 0.5, 0.42, 0.42, 0.30
72 };
73
74 G1Analytics::G1Analytics(const G1Predictions* predictor) :
75 _predictor(predictor),
76 _recent_gc_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
77 _concurrent_mark_remark_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
78 _concurrent_mark_cleanup_times_ms(new TruncatedSeq(NumPrevPausesForHeuristics)),
79 _alloc_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
80 _prev_collection_pause_end_ms(0.0),
81 _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
82 _concurrent_refine_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
83 _logged_cards_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
84 _cost_per_logged_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
85 _cost_scan_hcc_seq(new TruncatedSeq(TruncatedSeqLength)),
86 _young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
87 _mixed_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
88 _young_only_cost_per_remset_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
89 _mixed_cost_per_remset_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
90 _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
91 _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
92 _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
93 _non_young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
94 _pending_cards_seq(new TruncatedSeq(TruncatedSeqLength)),
95 _rs_length_seq(new TruncatedSeq(TruncatedSeqLength)),
96 _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
97 _recent_prev_end_times_for_all_gcs_sec(new TruncatedSeq(NumPrevPausesForHeuristics)),
98 _recent_avg_pause_time_ratio(0.0),
99 _last_pause_time_ratio(0.0) {
100
101 // Seed sequences with initial values.
102 _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime());
103 _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0;
104
105 int index = MIN2(ParallelGCThreads - 1, 7u);
106
107 _rs_length_diff_seq->add(rs_length_diff_defaults[index]);
108 // Start with inverse of maximum STW cost.
109 _concurrent_refine_rate_ms_seq->add(1/cost_per_logged_card_ms_defaults[0]);
110 // Some applications have very low rates for logging cards.
111 _logged_cards_rate_ms_seq->add(0.0);
112 _cost_per_logged_card_ms_seq->add(cost_per_logged_card_ms_defaults[index]);
113 _cost_scan_hcc_seq->add(0.0);
114 _young_cards_per_entry_ratio_seq->add(young_cards_per_entry_ratio_defaults[index]);
115 _young_only_cost_per_remset_card_ms_seq->add(young_only_cost_per_remset_card_ms_defaults[index]);
116 _cost_per_byte_ms_seq->add(cost_per_byte_ms_defaults[index]);
117 _constant_other_time_ms_seq->add(constant_other_time_ms_defaults[index]);
118 _young_other_cost_per_region_ms_seq->add(young_other_cost_per_region_ms_defaults[index]);
119 _non_young_other_cost_per_region_ms_seq->add(non_young_other_cost_per_region_ms_defaults[index]);
120
121 // start conservatively (around 50ms is about right)
122 _concurrent_mark_remark_times_ms->add(0.05);
123 _concurrent_mark_cleanup_times_ms->add(0.20);
124 }
125
126 double G1Analytics::get_new_prediction(TruncatedSeq const* seq) const {
127 return _predictor->get_new_prediction(seq);
128 }
129
130 size_t G1Analytics::get_new_size_prediction(TruncatedSeq const* seq) const {
131 return (size_t)get_new_prediction(seq);
132 }
133
134 int G1Analytics::num_alloc_rate_ms() const {
135 return _alloc_rate_ms_seq->num();
136 }
137
138 void G1Analytics::report_concurrent_mark_remark_times_ms(double ms) {
139 _concurrent_mark_remark_times_ms->add(ms);
140 }
141
142 void G1Analytics::report_alloc_rate_ms(double alloc_rate) {
143 _alloc_rate_ms_seq->add(alloc_rate);
144 }
145
146 void G1Analytics::compute_pause_time_ratio(double interval_ms, double pause_time_ms) {
147 _recent_avg_pause_time_ratio = _recent_gc_times_ms->sum() / interval_ms;
148
149 // Clamp the result to [0.0 ... 1.0] to filter out nonsensical results due to bad input.
150 _recent_avg_pause_time_ratio = clamp(_recent_avg_pause_time_ratio, 0.0, 1.0);
151
152 // Compute the ratio of just this last pause time to the entire time range stored
153 // in the vectors. Comparing this pause to the entire range, rather than only the
154 // most recent interval, has the effect of smoothing over a possible transient 'burst'
155 // of more frequent pauses that don't really reflect a change in heap occupancy.
156 // This reduces the likelihood of a needless heap expansion being triggered.
157 _last_pause_time_ratio =
158 (pause_time_ms * _recent_prev_end_times_for_all_gcs_sec->num()) / interval_ms;
159 }
160
161 void G1Analytics::report_concurrent_refine_rate_ms(double cards_per_ms) {
162 _concurrent_refine_rate_ms_seq->add(cards_per_ms);
163 }
164
165 void G1Analytics::report_logged_cards_rate_ms(double cards_per_ms) {
166 _logged_cards_rate_ms_seq->add(cards_per_ms);
167 }
168
169 void G1Analytics::report_cost_per_logged_card_ms(double cost_per_logged_card_ms) {
170 _cost_per_logged_card_ms_seq->add(cost_per_logged_card_ms);
171 }
172
173 void G1Analytics::report_cost_scan_hcc(double cost_scan_hcc) {
174 _cost_scan_hcc_seq->add(cost_scan_hcc);
175 }
176
177 void G1Analytics::report_cost_per_remset_card_ms(double cost_per_remset_card_ms, bool for_young_gc) {
178 if (for_young_gc) {
179 _young_only_cost_per_remset_card_ms_seq->add(cost_per_remset_card_ms);
180 } else {
181 _mixed_cost_per_remset_card_ms_seq->add(cost_per_remset_card_ms);
182 }
183 }
184
185 void G1Analytics::report_cards_per_entry_ratio(double cards_per_entry_ratio, bool for_young_gc) {
186 if (for_young_gc) {
187 _young_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
188 } else {
189 _mixed_cards_per_entry_ratio_seq->add(cards_per_entry_ratio);
190 }
191 }
192
193 void G1Analytics::report_rs_length_diff(double rs_length_diff) {
194 _rs_length_diff_seq->add(rs_length_diff);
195 }
196
197 void G1Analytics::report_cost_per_byte_ms(double cost_per_byte_ms, bool mark_or_rebuild_in_progress) {
198 if (mark_or_rebuild_in_progress) {
199 _cost_per_byte_ms_during_cm_seq->add(cost_per_byte_ms);
200 } else {
201 _cost_per_byte_ms_seq->add(cost_per_byte_ms);
202 }
203 }
204
205 void G1Analytics::report_young_other_cost_per_region_ms(double other_cost_per_region_ms) {
206 _young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms);
207 }
208
209 void G1Analytics::report_non_young_other_cost_per_region_ms(double other_cost_per_region_ms) {
210 _non_young_other_cost_per_region_ms_seq->add(other_cost_per_region_ms);
211 }
212
213 void G1Analytics::report_constant_other_time_ms(double constant_other_time_ms) {
214 _constant_other_time_ms_seq->add(constant_other_time_ms);
215 }
216
217 void G1Analytics::report_pending_cards(double pending_cards) {
218 _pending_cards_seq->add(pending_cards);
219 }
220
221 void G1Analytics::report_rs_length(double rs_length) {
222 _rs_length_seq->add(rs_length);
223 }
224
225 double G1Analytics::predict_alloc_rate_ms() const {
226 return get_new_prediction(_alloc_rate_ms_seq);
227 }
228
229 double G1Analytics::predict_concurrent_refine_rate_ms() const {
230 return get_new_prediction(_concurrent_refine_rate_ms_seq);
231 }
232
233 double G1Analytics::predict_logged_cards_rate_ms() const {
234 return get_new_prediction(_logged_cards_rate_ms_seq);
235 }
236
237 double G1Analytics::predict_cost_per_logged_card_ms() const {
238 return get_new_prediction(_cost_per_logged_card_ms_seq);
239 }
240
241 double G1Analytics::predict_scan_hcc_ms() const {
242 return get_new_prediction(_cost_scan_hcc_seq);
243 }
244
245 double G1Analytics::predict_rs_update_time_ms(size_t pending_cards) const {
246 return pending_cards * predict_cost_per_logged_card_ms() + predict_scan_hcc_ms();
247 }
248
249 double G1Analytics::predict_young_cards_per_entry_ratio() const {
250 return get_new_prediction(_young_cards_per_entry_ratio_seq);
251 }
252
253 double G1Analytics::predict_mixed_cards_per_entry_ratio() const {
254 if (_mixed_cards_per_entry_ratio_seq->num() < 2) {
255 return predict_young_cards_per_entry_ratio();
256 } else {
257 return get_new_prediction(_mixed_cards_per_entry_ratio_seq);
258 }
259 }
260
261 size_t G1Analytics::predict_card_num(size_t rs_length, bool for_young_gc) const {
262 if (for_young_gc) {
263 return (size_t) (rs_length * predict_young_cards_per_entry_ratio());
264 } else {
265 return (size_t) (rs_length * predict_mixed_cards_per_entry_ratio());
266 }
267 }
268
269 double G1Analytics::predict_rs_scan_time_ms(size_t card_num, bool for_young_gc) const {
270 if (for_young_gc) {
271 return card_num * get_new_prediction(_young_only_cost_per_remset_card_ms_seq);
272 } else {
273 return predict_mixed_rs_scan_time_ms(card_num);
274 }
275 }
276
277 double G1Analytics::predict_mixed_rs_scan_time_ms(size_t card_num) const {
278 if (_mixed_cost_per_remset_card_ms_seq->num() < 3) {
279 return card_num * get_new_prediction(_young_only_cost_per_remset_card_ms_seq);
280 } else {
281 return card_num * get_new_prediction(_mixed_cost_per_remset_card_ms_seq);
282 }
283 }
284
285 double G1Analytics::predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) const {
286 if (_cost_per_byte_ms_during_cm_seq->num() < 3) {
287 return (1.1 * bytes_to_copy) * get_new_prediction(_cost_per_byte_ms_seq);
288 } else {
289 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_during_cm_seq);
290 }
291 }
292
293 double G1Analytics::predict_object_copy_time_ms(size_t bytes_to_copy, bool during_concurrent_mark) const {
294 if (during_concurrent_mark) {
295 return predict_object_copy_time_ms_during_cm(bytes_to_copy);
296 } else {
297 return bytes_to_copy * get_new_prediction(_cost_per_byte_ms_seq);
298 }
299 }
300
301 double G1Analytics::predict_cost_per_byte_ms() const {
302 return get_new_prediction(_cost_per_byte_ms_seq);
303 }
304
305 double G1Analytics::predict_constant_other_time_ms() const {
306 return get_new_prediction(_constant_other_time_ms_seq);
307 }
308
309 double G1Analytics::predict_young_other_time_ms(size_t young_num) const {
310 return young_num * get_new_prediction(_young_other_cost_per_region_ms_seq);
311 }
312
313 double G1Analytics::predict_non_young_other_time_ms(size_t non_young_num) const {
314 return non_young_num * get_new_prediction(_non_young_other_cost_per_region_ms_seq);
315 }
316
317 double G1Analytics::predict_remark_time_ms() const {
318 return get_new_prediction(_concurrent_mark_remark_times_ms);
319 }
320
321 double G1Analytics::predict_cleanup_time_ms() const {
322 return get_new_prediction(_concurrent_mark_cleanup_times_ms);
323 }
324
325 size_t G1Analytics::predict_rs_length() const {
326 return get_new_size_prediction(_rs_length_seq) + get_new_prediction(_rs_length_diff_seq);
327 }
328
329 size_t G1Analytics::predict_pending_cards() const {
330 return get_new_size_prediction(_pending_cards_seq);
331 }
332
333 double G1Analytics::last_known_gc_end_time_sec() const {
334 return _recent_prev_end_times_for_all_gcs_sec->oldest();
335 }
336
337 void G1Analytics::update_recent_gc_times(double end_time_sec,
338 double pause_time_ms) {
339 _recent_gc_times_ms->add(pause_time_ms);
340 _recent_prev_end_times_for_all_gcs_sec->add(end_time_sec);
341 _prev_collection_pause_end_ms = end_time_sec * 1000.0;
342 }
343
344 void G1Analytics::report_concurrent_mark_cleanup_times_ms(double ms) {
345 _concurrent_mark_cleanup_times_ms->add(ms);
346 }