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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_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() const {
127   return _in_shutdown.is_set();
128 }
129 
130 bool ShenandoahCollectorPolicy::is_explicit_gc(GCCause::Cause cause) {
131   return GCCause::is_user_requested_gc(cause)
132       || GCCause::is_serviceability_requested_gc(cause)
133       || cause == GCCause::_wb_full_gc
134       || cause == GCCause::_wb_young_gc;
135 }
136 
137 bool is_implicit_gc(GCCause::Cause cause) {
138   return cause != GCCause::_no_gc
139       && cause != GCCause::_shenandoah_concurrent_gc
140       && cause != GCCause::_allocation_failure
141       && !ShenandoahCollectorPolicy::is_explicit_gc(cause);
142 }
143 
144 #ifdef ASSERT
145 bool is_valid_request(GCCause::Cause cause) {
146   return ShenandoahCollectorPolicy::is_explicit_gc(cause)
147       || ShenandoahCollectorPolicy::is_shenandoah_gc(cause)
148       || cause == GCCause::_metadata_GC_clear_soft_refs
149       || cause == GCCause::_codecache_GC_aggressive
150       || cause == GCCause::_codecache_GC_threshold
151       || cause == GCCause::_full_gc_alot
152       || cause == GCCause::_wb_young_gc
153       || cause == GCCause::_wb_full_gc
154       || cause == GCCause::_wb_breakpoint
155       || cause == GCCause::_scavenge_alot;
156 }
157 #endif
158 
159 bool ShenandoahCollectorPolicy::is_shenandoah_gc(GCCause::Cause cause) {
160   return cause == GCCause::_allocation_failure
161       || cause == GCCause::_shenandoah_stop_vm
162       || cause == GCCause::_shenandoah_allocation_failure_evac
163       || cause == GCCause::_shenandoah_humongous_allocation_failure
164       || cause == GCCause::_shenandoah_concurrent_gc
165       || cause == GCCause::_shenandoah_upgrade_to_full_gc;
166 }
167 
168 
169 bool ShenandoahCollectorPolicy::is_allocation_failure(GCCause::Cause cause) {
170   return cause == GCCause::_allocation_failure
171       || cause == GCCause::_shenandoah_allocation_failure_evac
172       || cause == GCCause::_shenandoah_humongous_allocation_failure;
173 }
174 
175 bool ShenandoahCollectorPolicy::is_requested_gc(GCCause::Cause cause) {
176   return is_explicit_gc(cause) || is_implicit_gc(cause);
177 }
178 
179 bool ShenandoahCollectorPolicy::should_run_full_gc(GCCause::Cause cause) {
180   return is_explicit_gc(cause) ? !ExplicitGCInvokesConcurrent : !ShenandoahImplicitGCInvokesConcurrent;
181 }
182 
183 bool ShenandoahCollectorPolicy::should_handle_requested_gc(GCCause::Cause cause) {
184   assert(is_valid_request(cause), "only requested GCs here: %s", GCCause::to_string(cause));
185 
186   if (DisableExplicitGC) {
187     return !is_explicit_gc(cause);
188   }
189   return true;
190 }
191 
192 void ShenandoahCollectorPolicy::print_gc_stats(outputStream* out) const {
193   out->print_cr("Under allocation pressure, concurrent cycles may cancel, and either continue cycle");
194   out->print_cr("under stop-the-world pause or result in stop-the-world Full GC. Increase heap size,");
195   out->print_cr("tune GC heuristics, set more aggressive pacing delay, or lower allocation rate");
196   out->print_cr("to avoid Degenerated and Full GC cycles. Abbreviated cycles are those which found");
197   out->print_cr("enough regions with no live objects to skip evacuation.");
198   out->cr();
199 
200   size_t completed_gcs = _success_full_gcs + _success_degenerated_gcs + _success_concurrent_gcs + _success_old_gcs;
201   out->print_cr(SIZE_FORMAT_W(5) " Completed GCs", completed_gcs);
202 
203   size_t explicit_requests = 0;
204   size_t implicit_requests = 0;
205   for (int c = 0; c < GCCause::_last_gc_cause; c++) {
206     size_t cause_count = _collection_cause_counts[c];
207     if (cause_count > 0) {
208       auto cause = (GCCause::Cause) c;
209       if (is_explicit_gc(cause)) {
210         explicit_requests += cause_count;
211       } else if (is_implicit_gc(cause)) {
212         implicit_requests += cause_count;
213       }
214       const char* desc = GCCause::to_string(cause);
215       out->print_cr("  " SIZE_FORMAT_W(5) " caused by %s (%.2f%%)", cause_count, desc, percent_of(cause_count, completed_gcs));
216     }
217   }
218 
219   out->cr();
220   out->print_cr(SIZE_FORMAT_W(5) " Successful Concurrent GCs (%.2f%%)", _success_concurrent_gcs, percent_of(_success_concurrent_gcs, completed_gcs));
221   if (ExplicitGCInvokesConcurrent) {
222     out->print_cr("  " SIZE_FORMAT_W(5) " invoked explicitly (%.2f%%)", explicit_requests, percent_of(explicit_requests, _success_concurrent_gcs));
223   }
224   if (ShenandoahImplicitGCInvokesConcurrent) {
225     out->print_cr("  " SIZE_FORMAT_W(5) " invoked implicitly (%.2f%%)", implicit_requests, percent_of(implicit_requests, _success_concurrent_gcs));
226   }
227   out->print_cr("  " SIZE_FORMAT_W(5) " abbreviated (%.2f%%)",  _abbreviated_concurrent_gcs, percent_of(_abbreviated_concurrent_gcs, _success_concurrent_gcs));
228   out->cr();
229 
230   if (ShenandoahHeap::heap()->mode()->is_generational()) {
231     out->print_cr(SIZE_FORMAT_W(5) " Completed Old GCs (%.2f%%)",        _success_old_gcs, percent_of(_success_old_gcs, completed_gcs));
232     out->print_cr("  " SIZE_FORMAT_W(5) " mixed",                        _mixed_gcs);
233     out->print_cr("  " SIZE_FORMAT_W(5) " interruptions",                _interrupted_old_gcs);
234     out->cr();
235   }
236 
237   size_t degenerated_gcs = _alloc_failure_degenerated_upgrade_to_full + _success_degenerated_gcs;
238   out->print_cr(SIZE_FORMAT_W(5) " Degenerated GCs (%.2f%%)", degenerated_gcs, percent_of(degenerated_gcs, completed_gcs));
239   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));
240   out->print_cr("  " SIZE_FORMAT_W(5) " caused by allocation failure (%.2f%%)", _alloc_failure_degenerated, percent_of(_alloc_failure_degenerated, degenerated_gcs));
241   out->print_cr("  " SIZE_FORMAT_W(5) " abbreviated (%.2f%%)",                  _abbreviated_degenerated_gcs, percent_of(_abbreviated_degenerated_gcs, degenerated_gcs));
242   for (int c = 0; c < ShenandoahGC::_DEGENERATED_LIMIT; c++) {
243     if (_degen_point_counts[c] > 0) {
244       const char* desc = ShenandoahGC::degen_point_to_string((ShenandoahGC::ShenandoahDegenPoint)c);
245       out->print_cr("    " SIZE_FORMAT_W(5) " happened at %s", _degen_point_counts[c], desc);
246     }
247   }

248   out->cr();
249 
250   out->print_cr(SIZE_FORMAT_W(5) " Full GCs (%.2f%%)", _success_full_gcs, percent_of(_success_full_gcs, completed_gcs));
251   if (!ExplicitGCInvokesConcurrent) {
252     out->print_cr("  " SIZE_FORMAT_W(5) " invoked explicitly (%.2f%%)", explicit_requests, percent_of(explicit_requests, _success_concurrent_gcs));
253   }
254   if (!ShenandoahImplicitGCInvokesConcurrent) {
255     out->print_cr("  " SIZE_FORMAT_W(5) " invoked implicitly (%.2f%%)", implicit_requests, percent_of(implicit_requests, _success_concurrent_gcs));
256   }
257   out->print_cr("  " SIZE_FORMAT_W(5) " caused by allocation failure (%.2f%%)", _alloc_failure_full, percent_of(_alloc_failure_full, _success_full_gcs));
258   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));
259 }
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