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src/hotspot/share/gc/shenandoah/shenandoahCollectorPolicy.cpp

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  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   _success_degenerated_gcs(0),

 35   _success_full_gcs(0),






 36   _alloc_failure_degenerated(0),
 37   _alloc_failure_degenerated_upgrade_to_full(0),
 38   _alloc_failure_full(0),
 39   _explicit_concurrent(0),
 40   _explicit_full(0),
 41   _implicit_concurrent(0),
 42   _implicit_full(0),
 43   _cycle_counter(0) {
 44 
 45   Copy::zero_to_bytes(_degen_points, sizeof(size_t) * ShenandoahGC::_DEGENERATED_LIMIT);

 46 
 47   _tracer = new ShenandoahTracer();
 48 
 49 }
 50 
 51 void ShenandoahCollectorPolicy::record_explicit_to_concurrent() {
 52   _explicit_concurrent++;
 53 }
 54 
 55 void ShenandoahCollectorPolicy::record_explicit_to_full() {
 56   _explicit_full++;
 57 }
 58 
 59 void ShenandoahCollectorPolicy::record_implicit_to_concurrent() {
 60   _implicit_concurrent++;
 61 }
 62 
 63 void ShenandoahCollectorPolicy::record_implicit_to_full() {
 64   _implicit_full++;

 65 }
 66 
 67 void ShenandoahCollectorPolicy::record_alloc_failure_to_full() {
 68   _alloc_failure_full++;
 69 }
 70 
 71 void ShenandoahCollectorPolicy::record_alloc_failure_to_degenerated(ShenandoahGC::ShenandoahDegenPoint point) {
 72   assert(point < ShenandoahGC::_DEGENERATED_LIMIT, "sanity");
 73   _alloc_failure_degenerated++;
 74   _degen_points[point]++;
 75 }
 76 
 77 void ShenandoahCollectorPolicy::record_degenerated_upgrade_to_full() {

 78   _alloc_failure_degenerated_upgrade_to_full++;
 79 }
 80 
 81 void ShenandoahCollectorPolicy::record_success_concurrent() {



 82   _success_concurrent_gcs++;



 83 }
 84 
 85 void ShenandoahCollectorPolicy::record_success_degenerated() {
 86   _success_degenerated_gcs++;
 87 }
 88 
 89 void ShenandoahCollectorPolicy::record_success_full() {
 90   _success_full_gcs++;






 91 }
 92 
 93 size_t ShenandoahCollectorPolicy::cycle_counter() const {
 94   return _cycle_counter;





















 95 }
 96 
 97 void ShenandoahCollectorPolicy::record_cycle_start() {
 98   _cycle_counter++;


 99 }
100 
101 void ShenandoahCollectorPolicy::record_shutdown() {
102   _in_shutdown.set();
103 }
104 
105 bool ShenandoahCollectorPolicy::is_at_shutdown() {
106   return _in_shutdown.is_set();
107 }
108 






























































109 void ShenandoahCollectorPolicy::print_gc_stats(outputStream* out) const {
110   out->print_cr("Under allocation pressure, concurrent cycles may cancel, and either continue cycle");
111   out->print_cr("under stop-the-world pause or result in stop-the-world Full GC. Increase heap size,");
112   out->print_cr("tune GC heuristics, set more aggressive pacing delay, or lower allocation rate");
113   out->print_cr("to avoid Degenerated and Full GC cycles.");

114   out->cr();
115 
116   out->print_cr(SIZE_FORMAT_W(5) " successful concurrent GCs",         _success_concurrent_gcs);
117   out->print_cr("  " SIZE_FORMAT_W(5) " invoked explicitly",           _explicit_concurrent);
118   out->print_cr("  " SIZE_FORMAT_W(5) " invoked implicitly",           _implicit_concurrent);
















119   out->cr();
















120 
121   out->print_cr(SIZE_FORMAT_W(5) " Degenerated GCs",                   _success_degenerated_gcs);
122   out->print_cr("  " SIZE_FORMAT_W(5) " caused by allocation failure", _alloc_failure_degenerated);



123   for (int c = 0; c < ShenandoahGC::_DEGENERATED_LIMIT; c++) {
124     if (_degen_points[c] > 0) {
125       const char* desc = ShenandoahGC::degen_point_to_string((ShenandoahGC::ShenandoahDegenPoint)c);
126       out->print_cr("    " SIZE_FORMAT_W(5) " happened at %s",         _degen_points[c], desc);
127     }
128   }
129   out->print_cr("  " SIZE_FORMAT_W(5) " upgraded to Full GC",          _alloc_failure_degenerated_upgrade_to_full);
130   out->cr();
131 
132   out->print_cr(SIZE_FORMAT_W(5) " Full GCs",                          _success_full_gcs + _alloc_failure_degenerated_upgrade_to_full);
133   out->print_cr("  " SIZE_FORMAT_W(5) " invoked explicitly",           _explicit_full);
134   out->print_cr("  " SIZE_FORMAT_W(5) " invoked implicitly",           _implicit_full);
135   out->print_cr("  " SIZE_FORMAT_W(5) " caused by allocation failure", _alloc_failure_full);
136   out->print_cr("  " SIZE_FORMAT_W(5) " upgraded from Degenerated GC", _alloc_failure_degenerated_upgrade_to_full);




137 }

  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_degenerated_gcs_without_progress(0),
 41   _consecutive_young_gcs(0),
 42   _mixed_gcs(0),
 43   _success_old_gcs(0),
 44   _interrupted_old_gcs(0),
 45   _alloc_failure_degenerated(0),
 46   _alloc_failure_degenerated_upgrade_to_full(0),
 47   _alloc_failure_full(0) {





 48 
 49   Copy::zero_to_bytes(_degen_point_counts, sizeof(size_t) * ShenandoahGC::_DEGENERATED_LIMIT);
 50   Copy::zero_to_bytes(_collection_cause_counts, sizeof(size_t) * GCCause::_last_gc_cause);
 51 
 52   _tracer = new ShenandoahTracer();













 53 }
 54 
 55 void ShenandoahCollectorPolicy::record_collection_cause(GCCause::Cause cause) {
 56   assert(cause < GCCause::_last_gc_cause, "Invalid GCCause");
 57   _collection_cause_counts[cause]++;
 58 }
 59 
 60 void ShenandoahCollectorPolicy::record_alloc_failure_to_full() {
 61   _alloc_failure_full++;
 62 }
 63 
 64 void ShenandoahCollectorPolicy::record_alloc_failure_to_degenerated(ShenandoahGC::ShenandoahDegenPoint point) {
 65   assert(point < ShenandoahGC::_DEGENERATED_LIMIT, "sanity");
 66   _alloc_failure_degenerated++;
 67   _degen_point_counts[point]++;
 68 }
 69 
 70 void ShenandoahCollectorPolicy::record_degenerated_upgrade_to_full() {
 71   reset_consecutive_degenerated_gcs();
 72   _alloc_failure_degenerated_upgrade_to_full++;
 73 }
 74 
 75 void ShenandoahCollectorPolicy::record_success_concurrent(bool is_young, bool is_abbreviated) {
 76   update_young(is_young);
 77 
 78   reset_consecutive_degenerated_gcs();
 79   _success_concurrent_gcs++;
 80   if (is_abbreviated) {
 81     _abbreviated_concurrent_gcs++;
 82   }
 83 }
 84 
 85 void ShenandoahCollectorPolicy::record_mixed_cycle() {
 86   _mixed_gcs++;
 87 }
 88 
 89 void ShenandoahCollectorPolicy::record_success_old() {
 90   _consecutive_young_gcs = 0;
 91   _success_old_gcs++;
 92 }
 93 
 94 void ShenandoahCollectorPolicy::record_interrupted_old() {
 95   _consecutive_young_gcs = 0;
 96   _interrupted_old_gcs++;
 97 }
 98 
 99 void ShenandoahCollectorPolicy::record_degenerated(bool is_young, bool is_abbreviated, bool progress) {
100   update_young(is_young);
101 
102   _success_degenerated_gcs++;
103   _consecutive_degenerated_gcs++;
104 
105   if (progress) {
106     _consecutive_degenerated_gcs_without_progress = 0;
107   } else {
108     _consecutive_degenerated_gcs_without_progress++;
109   }
110 
111   if (is_abbreviated) {
112     _abbreviated_degenerated_gcs++;
113   }
114 }
115 
116 void ShenandoahCollectorPolicy::update_young(bool is_young) {
117   if (is_young) {
118     _consecutive_young_gcs++;
119   } else {
120     _consecutive_young_gcs = 0;
121   }
122 }
123 
124 void ShenandoahCollectorPolicy::record_success_full() {
125   reset_consecutive_degenerated_gcs();
126   _consecutive_young_gcs = 0;
127   _success_full_gcs++;
128 }
129 
130 void ShenandoahCollectorPolicy::record_shutdown() {
131   _in_shutdown.set();
132 }
133 
134 bool ShenandoahCollectorPolicy::is_at_shutdown() const {
135   return _in_shutdown.is_set();
136 }
137 
138 bool ShenandoahCollectorPolicy::is_explicit_gc(GCCause::Cause cause) {
139   return GCCause::is_user_requested_gc(cause)
140       || GCCause::is_serviceability_requested_gc(cause)
141       || cause == GCCause::_wb_full_gc
142       || cause == GCCause::_wb_young_gc;
143 }
144 
145 bool is_implicit_gc(GCCause::Cause cause) {
146   return cause != GCCause::_no_gc
147       && cause != GCCause::_shenandoah_concurrent_gc
148       && cause != GCCause::_allocation_failure
149       && !ShenandoahCollectorPolicy::is_explicit_gc(cause);
150 }
151 
152 #ifdef ASSERT
153 bool is_valid_request(GCCause::Cause cause) {
154   return ShenandoahCollectorPolicy::is_explicit_gc(cause)
155       || ShenandoahCollectorPolicy::is_shenandoah_gc(cause)
156       || cause == GCCause::_metadata_GC_clear_soft_refs
157       || cause == GCCause::_codecache_GC_aggressive
158       || cause == GCCause::_codecache_GC_threshold
159       || cause == GCCause::_full_gc_alot
160       || cause == GCCause::_wb_young_gc
161       || cause == GCCause::_wb_full_gc
162       || cause == GCCause::_wb_breakpoint
163       || cause == GCCause::_scavenge_alot;
164 }
165 #endif
166 
167 bool ShenandoahCollectorPolicy::is_shenandoah_gc(GCCause::Cause cause) {
168   return cause == GCCause::_allocation_failure
169       || cause == GCCause::_shenandoah_stop_vm
170       || cause == GCCause::_shenandoah_allocation_failure_evac
171       || cause == GCCause::_shenandoah_humongous_allocation_failure
172       || cause == GCCause::_shenandoah_concurrent_gc
173       || cause == GCCause::_shenandoah_upgrade_to_full_gc;
174 }
175 
176 
177 bool ShenandoahCollectorPolicy::is_allocation_failure(GCCause::Cause cause) {
178   return cause == GCCause::_allocation_failure
179       || cause == GCCause::_shenandoah_allocation_failure_evac
180       || cause == GCCause::_shenandoah_humongous_allocation_failure;
181 }
182 
183 bool ShenandoahCollectorPolicy::is_requested_gc(GCCause::Cause cause) {
184   return is_explicit_gc(cause) || is_implicit_gc(cause);
185 }
186 
187 bool ShenandoahCollectorPolicy::should_run_full_gc(GCCause::Cause cause) {
188   return is_explicit_gc(cause) ? !ExplicitGCInvokesConcurrent : !ShenandoahImplicitGCInvokesConcurrent;
189 }
190 
191 bool ShenandoahCollectorPolicy::should_handle_requested_gc(GCCause::Cause cause) {
192   assert(is_valid_request(cause), "only requested GCs here: %s", GCCause::to_string(cause));
193 
194   if (DisableExplicitGC) {
195     return !is_explicit_gc(cause);
196   }
197   return true;
198 }
199 
200 void ShenandoahCollectorPolicy::print_gc_stats(outputStream* out) const {
201   out->print_cr("Under allocation pressure, concurrent cycles may cancel, and either continue cycle");
202   out->print_cr("under stop-the-world pause or result in stop-the-world Full GC. Increase heap size,");
203   out->print_cr("tune GC heuristics, set more aggressive pacing delay, or lower allocation rate");
204   out->print_cr("to avoid Degenerated and Full GC cycles. Abbreviated cycles are those which found");
205   out->print_cr("enough regions with no live objects to skip evacuation.");
206   out->cr();
207 
208   size_t completed_gcs = _success_full_gcs + _success_degenerated_gcs + _success_concurrent_gcs + _success_old_gcs;
209   out->print_cr(SIZE_FORMAT_W(5) " Completed GCs", completed_gcs);
210 
211   size_t explicit_requests = 0;
212   size_t implicit_requests = 0;
213   for (int c = 0; c < GCCause::_last_gc_cause; c++) {
214     size_t cause_count = _collection_cause_counts[c];
215     if (cause_count > 0) {
216       auto cause = (GCCause::Cause) c;
217       if (is_explicit_gc(cause)) {
218         explicit_requests += cause_count;
219       } else if (is_implicit_gc(cause)) {
220         implicit_requests += cause_count;
221       }
222       const char* desc = GCCause::to_string(cause);
223       out->print_cr("  " SIZE_FORMAT_W(5) " caused by %s (%.2f%%)", cause_count, desc, percent_of(cause_count, completed_gcs));
224     }
225   }
226 
227   out->cr();
228   out->print_cr(SIZE_FORMAT_W(5) " Successful Concurrent GCs (%.2f%%)", _success_concurrent_gcs, percent_of(_success_concurrent_gcs, completed_gcs));
229   if (ExplicitGCInvokesConcurrent) {
230     out->print_cr("  " SIZE_FORMAT_W(5) " invoked explicitly (%.2f%%)", explicit_requests, percent_of(explicit_requests, _success_concurrent_gcs));
231   }
232   if (ShenandoahImplicitGCInvokesConcurrent) {
233     out->print_cr("  " SIZE_FORMAT_W(5) " invoked implicitly (%.2f%%)", implicit_requests, percent_of(implicit_requests, _success_concurrent_gcs));
234   }
235   out->print_cr("  " SIZE_FORMAT_W(5) " abbreviated (%.2f%%)",  _abbreviated_concurrent_gcs, percent_of(_abbreviated_concurrent_gcs, _success_concurrent_gcs));
236   out->cr();
237 
238   if (ShenandoahHeap::heap()->mode()->is_generational()) {
239     out->print_cr(SIZE_FORMAT_W(5) " Completed Old GCs (%.2f%%)",        _success_old_gcs, percent_of(_success_old_gcs, completed_gcs));
240     out->print_cr("  " SIZE_FORMAT_W(5) " mixed",                        _mixed_gcs);
241     out->print_cr("  " SIZE_FORMAT_W(5) " interruptions",                _interrupted_old_gcs);
242     out->cr();
243   }
244 
245   size_t degenerated_gcs = _alloc_failure_degenerated_upgrade_to_full + _success_degenerated_gcs;
246   out->print_cr(SIZE_FORMAT_W(5) " Degenerated GCs (%.2f%%)", degenerated_gcs, percent_of(degenerated_gcs, completed_gcs));
247   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));
248   out->print_cr("  " SIZE_FORMAT_W(5) " caused by allocation failure (%.2f%%)", _alloc_failure_degenerated, percent_of(_alloc_failure_degenerated, degenerated_gcs));
249   out->print_cr("  " SIZE_FORMAT_W(5) " abbreviated (%.2f%%)",                  _abbreviated_degenerated_gcs, percent_of(_abbreviated_degenerated_gcs, degenerated_gcs));
250   for (int c = 0; c < ShenandoahGC::_DEGENERATED_LIMIT; c++) {
251     if (_degen_point_counts[c] > 0) {
252       const char* desc = ShenandoahGC::degen_point_to_string((ShenandoahGC::ShenandoahDegenPoint)c);
253       out->print_cr("    " SIZE_FORMAT_W(5) " happened at %s", _degen_point_counts[c], desc);
254     }
255   }

256   out->cr();
257 
258   out->print_cr(SIZE_FORMAT_W(5) " Full GCs (%.2f%%)", _success_full_gcs, percent_of(_success_full_gcs, completed_gcs));
259   if (!ExplicitGCInvokesConcurrent) {
260     out->print_cr("  " SIZE_FORMAT_W(5) " invoked explicitly (%.2f%%)", explicit_requests, percent_of(explicit_requests, _success_concurrent_gcs));
261   }
262   if (!ShenandoahImplicitGCInvokesConcurrent) {
263     out->print_cr("  " SIZE_FORMAT_W(5) " invoked implicitly (%.2f%%)", implicit_requests, percent_of(implicit_requests, _success_concurrent_gcs));
264   }
265   out->print_cr("  " SIZE_FORMAT_W(5) " caused by allocation failure (%.2f%%)", _alloc_failure_full, percent_of(_alloc_failure_full, _success_full_gcs));
266   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));
267 }
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