1 /*
2 * Copyright (c) 2013, 2021, Red Hat, Inc. 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
27 #include "gc/shenandoah/shenandoahCollectorPolicy.hpp"
28 #include "gc/shenandoah/shenandoahGC.hpp"
29 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
30 #include "runtime/os.hpp"
31
32 ShenandoahCollectorPolicy::ShenandoahCollectorPolicy() :
33 _success_concurrent_gcs(0),
34 _abbreviated_concurrent_gcs(0),
35 _success_degenerated_gcs(0),
36 _abbreviated_degenerated_gcs(0),
37 _success_full_gcs(0),
38 _consecutive_degenerated_gcs(0),
39 _alloc_failure_degenerated(0),
40 _alloc_failure_degenerated_upgrade_to_full(0),
41 _alloc_failure_full(0) {
42
43 Copy::zero_to_bytes(_degen_point_counts, sizeof(size_t) * ShenandoahGC::_DEGENERATED_LIMIT);
44 Copy::zero_to_bytes(_collection_cause_counts, sizeof(size_t) * GCCause::_last_gc_cause);
45
46 _tracer = new ShenandoahTracer();
47 }
48
49 void ShenandoahCollectorPolicy::record_collection_cause(GCCause::Cause cause) {
50 assert(cause < GCCause::_last_gc_cause, "Invalid GCCause");
51 _collection_cause_counts[cause]++;
52 }
53
54 void ShenandoahCollectorPolicy::record_alloc_failure_to_full() {
55 _alloc_failure_full++;
56 }
57
58 void ShenandoahCollectorPolicy::record_alloc_failure_to_degenerated(ShenandoahGC::ShenandoahDegenPoint point) {
59 assert(point < ShenandoahGC::_DEGENERATED_LIMIT, "sanity");
60 _alloc_failure_degenerated++;
61 _degen_point_counts[point]++;
62 }
63
64 void ShenandoahCollectorPolicy::record_degenerated_upgrade_to_full() {
65 _consecutive_degenerated_gcs = 0;
66 _alloc_failure_degenerated_upgrade_to_full++;
67 }
68
69 void ShenandoahCollectorPolicy::record_success_concurrent(bool is_abbreviated) {
70 _consecutive_degenerated_gcs = 0;
71 _success_concurrent_gcs++;
72 if (is_abbreviated) {
73 _abbreviated_concurrent_gcs++;
74 }
75 }
76
77 void ShenandoahCollectorPolicy::record_success_degenerated(bool is_abbreviated) {
78 _success_degenerated_gcs++;
79 _consecutive_degenerated_gcs++;
80 if (is_abbreviated) {
81 _abbreviated_degenerated_gcs++;
82 }
83 }
84
85 void ShenandoahCollectorPolicy::record_success_full() {
86 _consecutive_degenerated_gcs = 0;
87 _success_full_gcs++;
88 }
89
90 void ShenandoahCollectorPolicy::record_shutdown() {
91 _in_shutdown.set();
92 }
93
94 bool ShenandoahCollectorPolicy::is_at_shutdown() {
95 return _in_shutdown.is_set();
96 }
97
98 bool is_explicit_gc(GCCause::Cause cause) {
99 return GCCause::is_user_requested_gc(cause)
100 || GCCause::is_serviceability_requested_gc(cause);
101 }
102
103 bool is_implicit_gc(GCCause::Cause cause) {
104 return cause != GCCause::_allocation_failure
105 && cause != GCCause::_shenandoah_concurrent_gc
106 && !is_explicit_gc(cause);
107 }
108
109 #ifdef ASSERT
110 bool is_valid_request(GCCause::Cause cause) {
111 return is_explicit_gc(cause)
112 || cause == GCCause::_metadata_GC_clear_soft_refs
113 || cause == GCCause::_codecache_GC_aggressive
114 || cause == GCCause::_codecache_GC_threshold
115 || cause == GCCause::_full_gc_alot
116 || cause == GCCause::_wb_young_gc
117 || cause == GCCause::_wb_full_gc
118 || cause == GCCause::_wb_breakpoint
119 || cause == GCCause::_scavenge_alot;
120 }
121 #endif
122
123 bool ShenandoahCollectorPolicy::should_run_full_gc(GCCause::Cause cause) {
124 return is_explicit_gc(cause) ? !ExplicitGCInvokesConcurrent : !ShenandoahImplicitGCInvokesConcurrent;
125 }
126
127 bool ShenandoahCollectorPolicy::should_handle_requested_gc(GCCause::Cause cause) {
128 assert(is_valid_request(cause), "only requested GCs here: %s", GCCause::to_string(cause));
129
130 if (DisableExplicitGC) {
131 return !is_explicit_gc(cause);
132 }
133 return true;
134 }
135
136 void ShenandoahCollectorPolicy::print_gc_stats(outputStream* out) const {
137 out->print_cr("Under allocation pressure, concurrent cycles may cancel, and either continue cycle");
138 out->print_cr("under stop-the-world pause or result in stop-the-world Full GC. Increase heap size,");
139 out->print_cr("tune GC heuristics, set more aggressive pacing delay, or lower allocation rate");
140 out->print_cr("to avoid Degenerated and Full GC cycles. Abbreviated cycles are those which found");
141 out->print_cr("enough regions with no live objects to skip evacuation.");
142 out->cr();
143
144 size_t completed_gcs = _success_full_gcs + _success_degenerated_gcs + _success_concurrent_gcs;
145 out->print_cr(SIZE_FORMAT_W(5) " Completed GCs", completed_gcs);
146
147 size_t explicit_requests = 0;
148 size_t implicit_requests = 0;
149 for (int c = 0; c < GCCause::_last_gc_cause; c++) {
150 size_t cause_count = _collection_cause_counts[c];
151 if (cause_count > 0) {
152 auto cause = (GCCause::Cause) c;
153 if (is_explicit_gc(cause)) {
154 explicit_requests += cause_count;
155 } else if (is_implicit_gc(cause)) {
156 implicit_requests += cause_count;
157 }
158 const char* desc = GCCause::to_string(cause);
159 out->print_cr(" " SIZE_FORMAT_W(5) " caused by %s (%.2f%%)", cause_count, desc, percent_of(cause_count, completed_gcs));
160 }
161 }
162
163 out->cr();
164 out->print_cr(SIZE_FORMAT_W(5) " Successful Concurrent GCs (%.2f%%)", _success_concurrent_gcs, percent_of(_success_concurrent_gcs, completed_gcs));
165 if (ExplicitGCInvokesConcurrent) {
166 out->print_cr(" " SIZE_FORMAT_W(5) " invoked explicitly (%.2f%%)", explicit_requests, percent_of(explicit_requests, _success_concurrent_gcs));
167 }
168 if (ShenandoahImplicitGCInvokesConcurrent) {
169 out->print_cr(" " SIZE_FORMAT_W(5) " invoked implicitly (%.2f%%)", implicit_requests, percent_of(implicit_requests, _success_concurrent_gcs));
170 }
171 out->print_cr(" " SIZE_FORMAT_W(5) " abbreviated (%.2f%%)", _abbreviated_concurrent_gcs, percent_of(_abbreviated_concurrent_gcs, _success_concurrent_gcs));
172 out->cr();
173
174 size_t degenerated_gcs = _alloc_failure_degenerated_upgrade_to_full + _success_degenerated_gcs;
175 out->print_cr(SIZE_FORMAT_W(5) " Degenerated GCs (%.2f%%)", degenerated_gcs, percent_of(degenerated_gcs, completed_gcs));
176 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));
177 out->print_cr(" " SIZE_FORMAT_W(5) " caused by allocation failure (%.2f%%)", _alloc_failure_degenerated, percent_of(_alloc_failure_degenerated, degenerated_gcs));
178 out->print_cr(" " SIZE_FORMAT_W(5) " abbreviated (%.2f%%)", _abbreviated_degenerated_gcs, percent_of(_abbreviated_degenerated_gcs, degenerated_gcs));
179 for (int c = 0; c < ShenandoahGC::_DEGENERATED_LIMIT; c++) {
180 if (_degen_point_counts[c] > 0) {
181 const char* desc = ShenandoahGC::degen_point_to_string((ShenandoahGC::ShenandoahDegenPoint)c);
182 out->print_cr(" " SIZE_FORMAT_W(5) " happened at %s", _degen_point_counts[c], desc);
183 }
184 }
185 out->cr();
186
187 out->print_cr(SIZE_FORMAT_W(5) " Full GCs (%.2f%%)", _success_full_gcs, percent_of(_success_full_gcs, completed_gcs));
188 if (!ExplicitGCInvokesConcurrent) {
189 out->print_cr(" " SIZE_FORMAT_W(5) " invoked explicitly (%.2f%%)", explicit_requests, percent_of(explicit_requests, _success_concurrent_gcs));
190 }
191 if (!ShenandoahImplicitGCInvokesConcurrent) {
192 out->print_cr(" " SIZE_FORMAT_W(5) " invoked implicitly (%.2f%%)", implicit_requests, percent_of(implicit_requests, _success_concurrent_gcs));
193 }
194 out->print_cr(" " SIZE_FORMAT_W(5) " caused by allocation failure (%.2f%%)", _alloc_failure_full, percent_of(_alloc_failure_full, _success_full_gcs));
195 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));
196 }