1 /*
2 * Copyright (c) 2013, 2021, Red Hat, Inc. All rights reserved.
3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27
28 #include "gc/shenandoah/shenandoahCollectorPolicy.hpp"
29 #include "gc/shenandoah/shenandoahGC.hpp"
30 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
31 #include "runtime/os.hpp"
32
33 ShenandoahCollectorPolicy::ShenandoahCollectorPolicy() :
34 _success_concurrent_gcs(0),
35 _abbreviated_concurrent_gcs(0),
36 _success_degenerated_gcs(0),
37 _abbreviated_degenerated_gcs(0),
38 _success_full_gcs(0),
39 _consecutive_degenerated_gcs(0),
40 _consecutive_young_gcs(0),
41 _mixed_gcs(0),
42 _success_old_gcs(0),
43 _interrupted_old_gcs(0),
44 _alloc_failure_degenerated(0),
45 _alloc_failure_degenerated_upgrade_to_full(0),
46 _alloc_failure_full(0) {
47
48 Copy::zero_to_bytes(_degen_point_counts, sizeof(size_t) * ShenandoahGC::_DEGENERATED_LIMIT);
49 Copy::zero_to_bytes(_collection_cause_counts, sizeof(size_t) * GCCause::_last_gc_cause);
50
51 _tracer = new ShenandoahTracer();
52 }
53
54 void ShenandoahCollectorPolicy::record_collection_cause(GCCause::Cause cause) {
55 assert(cause < GCCause::_last_gc_cause, "Invalid GCCause");
56 _collection_cause_counts[cause]++;
57 }
58
59 void ShenandoahCollectorPolicy::record_alloc_failure_to_full() {
60 _alloc_failure_full++;
61 }
62
63 void ShenandoahCollectorPolicy::record_alloc_failure_to_degenerated(ShenandoahGC::ShenandoahDegenPoint point) {
64 assert(point < ShenandoahGC::_DEGENERATED_LIMIT, "sanity");
65 _alloc_failure_degenerated++;
66 _degen_point_counts[point]++;
67 }
68
69 void ShenandoahCollectorPolicy::record_degenerated_upgrade_to_full() {
70 _consecutive_degenerated_gcs = 0;
71 _alloc_failure_degenerated_upgrade_to_full++;
72 }
73
74 void ShenandoahCollectorPolicy::record_success_concurrent(bool is_young, bool is_abbreviated) {
75 update_young(is_young);
76
77 _consecutive_degenerated_gcs = 0;
78 _success_concurrent_gcs++;
79 if (is_abbreviated) {
80 _abbreviated_concurrent_gcs++;
81 }
82 }
83
84 void ShenandoahCollectorPolicy::record_mixed_cycle() {
85 _mixed_gcs++;
86 }
87
88 void ShenandoahCollectorPolicy::record_success_old() {
89 _consecutive_young_gcs = 0;
90 _success_old_gcs++;
91 }
92
93 void ShenandoahCollectorPolicy::record_interrupted_old() {
94 _consecutive_young_gcs = 0;
95 _interrupted_old_gcs++;
96 }
97
98 void ShenandoahCollectorPolicy::record_success_degenerated(bool is_young, bool is_abbreviated) {
99 update_young(is_young);
100
101 _success_degenerated_gcs++;
102 _consecutive_degenerated_gcs++;
103 if (is_abbreviated) {
104 _abbreviated_degenerated_gcs++;
105 }
106 }
107
108 void ShenandoahCollectorPolicy::update_young(bool is_young) {
109 if (is_young) {
110 _consecutive_young_gcs++;
111 } else {
112 _consecutive_young_gcs = 0;
113 }
114 }
115
116 void ShenandoahCollectorPolicy::record_success_full() {
117 _consecutive_degenerated_gcs = 0;
118 _consecutive_young_gcs = 0;
119 _success_full_gcs++;
120 }
121
122 void ShenandoahCollectorPolicy::record_shutdown() {
123 _in_shutdown.set();
124 }
125
126 bool ShenandoahCollectorPolicy::is_at_shutdown() {
127 return _in_shutdown.is_set();
128 }
129
130 bool is_explicit_gc(GCCause::Cause cause) {
131 return GCCause::is_user_requested_gc(cause)
132 || GCCause::is_serviceability_requested_gc(cause);
133 }
134
135 bool is_implicit_gc(GCCause::Cause cause) {
136 return cause != GCCause::_no_gc
137 && cause != GCCause::_shenandoah_concurrent_gc
138 && cause != GCCause::_allocation_failure
139 && !is_explicit_gc(cause);
140 }
141
142 #ifdef ASSERT
143 bool is_valid_request(GCCause::Cause cause) {
144 return is_explicit_gc(cause)
145 || cause == GCCause::_metadata_GC_clear_soft_refs
146 || cause == GCCause::_codecache_GC_aggressive
147 || cause == GCCause::_codecache_GC_threshold
148 || cause == GCCause::_full_gc_alot
149 || cause == GCCause::_wb_young_gc
150 || cause == GCCause::_wb_full_gc
151 || cause == GCCause::_wb_breakpoint
152 || cause == GCCause::_scavenge_alot;
153 }
154 #endif
155
156 bool ShenandoahCollectorPolicy::is_requested_gc(GCCause::Cause cause) {
157 return is_explicit_gc(cause) || is_implicit_gc(cause);
158 }
159
160 bool ShenandoahCollectorPolicy::should_run_full_gc(GCCause::Cause cause) {
161 return is_explicit_gc(cause) ? !ExplicitGCInvokesConcurrent : !ShenandoahImplicitGCInvokesConcurrent;
162 }
163
164 bool ShenandoahCollectorPolicy::should_handle_requested_gc(GCCause::Cause cause) {
165 assert(is_valid_request(cause), "only requested GCs here: %s", GCCause::to_string(cause));
166
167 if (DisableExplicitGC) {
168 return !is_explicit_gc(cause);
169 }
170 return true;
171 }
172
173 void ShenandoahCollectorPolicy::print_gc_stats(outputStream* out) const {
174 out->print_cr("Under allocation pressure, concurrent cycles may cancel, and either continue cycle");
175 out->print_cr("under stop-the-world pause or result in stop-the-world Full GC. Increase heap size,");
176 out->print_cr("tune GC heuristics, set more aggressive pacing delay, or lower allocation rate");
177 out->print_cr("to avoid Degenerated and Full GC cycles. Abbreviated cycles are those which found");
178 out->print_cr("enough regions with no live objects to skip evacuation.");
179 out->cr();
180
181 size_t completed_gcs = _success_full_gcs + _success_degenerated_gcs + _success_concurrent_gcs + _success_old_gcs;
182 out->print_cr(SIZE_FORMAT_W(5) " Completed GCs", completed_gcs);
183
184 size_t explicit_requests = 0;
185 size_t implicit_requests = 0;
186 for (int c = 0; c < GCCause::_last_gc_cause; c++) {
187 size_t cause_count = _collection_cause_counts[c];
188 if (cause_count > 0) {
189 auto cause = (GCCause::Cause) c;
190 if (is_explicit_gc(cause)) {
191 explicit_requests += cause_count;
192 } else if (is_implicit_gc(cause)) {
193 implicit_requests += cause_count;
194 }
195 const char* desc = GCCause::to_string(cause);
196 out->print_cr(" " SIZE_FORMAT_W(5) " caused by %s (%.2f%%)", cause_count, desc, percent_of(cause_count, completed_gcs));
197 }
198 }
199
200 out->cr();
201 out->print_cr(SIZE_FORMAT_W(5) " Successful Concurrent GCs (%.2f%%)", _success_concurrent_gcs, percent_of(_success_concurrent_gcs, completed_gcs));
202 if (ExplicitGCInvokesConcurrent) {
203 out->print_cr(" " SIZE_FORMAT_W(5) " invoked explicitly (%.2f%%)", explicit_requests, percent_of(explicit_requests, _success_concurrent_gcs));
204 }
205 if (ShenandoahImplicitGCInvokesConcurrent) {
206 out->print_cr(" " SIZE_FORMAT_W(5) " invoked implicitly (%.2f%%)", implicit_requests, percent_of(implicit_requests, _success_concurrent_gcs));
207 }
208 out->print_cr(" " SIZE_FORMAT_W(5) " abbreviated (%.2f%%)", _abbreviated_concurrent_gcs, percent_of(_abbreviated_concurrent_gcs, _success_concurrent_gcs));
209 out->cr();
210
211 if (ShenandoahHeap::heap()->mode()->is_generational()) {
212 out->print_cr(SIZE_FORMAT_W(5) " Completed Old GCs (%.2f%%)", _success_old_gcs, percent_of(_success_old_gcs, completed_gcs));
213 out->print_cr(" " SIZE_FORMAT_W(5) " mixed", _mixed_gcs);
214 out->print_cr(" " SIZE_FORMAT_W(5) " interruptions", _interrupted_old_gcs);
215 out->cr();
216 }
217
218 size_t degenerated_gcs = _alloc_failure_degenerated_upgrade_to_full + _success_degenerated_gcs;
219 out->print_cr(SIZE_FORMAT_W(5) " Degenerated GCs (%.2f%%)", degenerated_gcs, percent_of(degenerated_gcs, completed_gcs));
220 out->print_cr(" " SIZE_FORMAT_W(5) " upgraded to Full GC (%.2f%%)", _alloc_failure_degenerated_upgrade_to_full, percent_of(_alloc_failure_degenerated_upgrade_to_full, degenerated_gcs));
221 out->print_cr(" " SIZE_FORMAT_W(5) " caused by allocation failure (%.2f%%)", _alloc_failure_degenerated, percent_of(_alloc_failure_degenerated, degenerated_gcs));
222 out->print_cr(" " SIZE_FORMAT_W(5) " abbreviated (%.2f%%)", _abbreviated_degenerated_gcs, percent_of(_abbreviated_degenerated_gcs, degenerated_gcs));
223 for (int c = 0; c < ShenandoahGC::_DEGENERATED_LIMIT; c++) {
224 if (_degen_point_counts[c] > 0) {
225 const char* desc = ShenandoahGC::degen_point_to_string((ShenandoahGC::ShenandoahDegenPoint)c);
226 out->print_cr(" " SIZE_FORMAT_W(5) " happened at %s", _degen_point_counts[c], desc);
227 }
228 }
229 out->cr();
230
231 out->print_cr(SIZE_FORMAT_W(5) " Full GCs (%.2f%%)", _success_full_gcs, percent_of(_success_full_gcs, completed_gcs));
232 if (!ExplicitGCInvokesConcurrent) {
233 out->print_cr(" " SIZE_FORMAT_W(5) " invoked explicitly (%.2f%%)", explicit_requests, percent_of(explicit_requests, _success_concurrent_gcs));
234 }
235 if (!ShenandoahImplicitGCInvokesConcurrent) {
236 out->print_cr(" " SIZE_FORMAT_W(5) " invoked implicitly (%.2f%%)", implicit_requests, percent_of(implicit_requests, _success_concurrent_gcs));
237 }
238 out->print_cr(" " SIZE_FORMAT_W(5) " caused by allocation failure (%.2f%%)", _alloc_failure_full, percent_of(_alloc_failure_full, _success_full_gcs));
239 out->print_cr(" " SIZE_FORMAT_W(5) " upgraded from Degenerated GC (%.2f%%)", _alloc_failure_degenerated_upgrade_to_full, percent_of(_alloc_failure_degenerated_upgrade_to_full, _success_full_gcs));
240 }