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1 /* |
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2 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 * |
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23 */ |
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24 |
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25 #include "precompiled.hpp" |
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26 #include "gc/shared/collectedHeap.hpp" |
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27 #include "jfr/leakprofiler/leakProfiler.hpp" |
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28 #include "jfr/leakprofiler/chains/bfsClosure.hpp" |
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29 #include "jfr/leakprofiler/chains/bitset.hpp" |
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30 #include "jfr/leakprofiler/chains/dfsClosure.hpp" |
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31 #include "jfr/leakprofiler/chains/edge.hpp" |
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32 #include "jfr/leakprofiler/chains/edgeQueue.hpp" |
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33 #include "jfr/leakprofiler/chains/edgeStore.hpp" |
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34 #include "jfr/leakprofiler/chains/objectSampleMarker.hpp" |
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35 #include "jfr/leakprofiler/chains/rootSetClosure.hpp" |
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36 #include "jfr/leakprofiler/chains/edgeStore.hpp" |
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37 #include "jfr/leakprofiler/chains/objectSampleMarker.hpp" |
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38 #include "jfr/leakprofiler/chains/pathToGcRootsOperation.hpp" |
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39 #include "jfr/leakprofiler/checkpoint/eventEmitter.hpp" |
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40 #include "jfr/leakprofiler/checkpoint/objectSampleCheckpoint.hpp" |
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41 #include "jfr/leakprofiler/sampling/objectSample.hpp" |
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42 #include "jfr/leakprofiler/sampling/objectSampler.hpp" |
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43 #include "jfr/leakprofiler/utilities/granularTimer.hpp" |
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44 #include "logging/log.hpp" |
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45 #include "memory/universe.hpp" |
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46 |
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47 #include "oops/oop.inline.hpp" |
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48 #include "runtime/safepoint.hpp" |
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49 #include "utilities/globalDefinitions.hpp" |
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50 |
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51 PathToGcRootsOperation::PathToGcRootsOperation(ObjectSampler* sampler, EdgeStore* edge_store, int64_t cutoff, bool emit_all) : |
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52 _sampler(sampler),_edge_store(edge_store), _cutoff_ticks(cutoff), _emit_all(emit_all) {} |
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53 |
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54 /* The EdgeQueue is backed by directly managed virtual memory. |
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55 * We will attempt to dimension an initial reservation |
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56 * in proportion to the size of the heap (represented by heap_region). |
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57 * Initial memory reservation: 5% of the heap OR at least 32 Mb |
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58 * Commit ratio: 1 : 10 (subject to allocation granularties) |
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59 */ |
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60 static size_t edge_queue_memory_reservation(const MemRegion& heap_region) { |
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61 const size_t memory_reservation_bytes = MAX2(heap_region.byte_size() / 20, 32*M); |
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62 assert(memory_reservation_bytes >= (size_t)32*M, "invariant"); |
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63 return memory_reservation_bytes; |
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64 } |
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65 |
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66 static size_t edge_queue_memory_commit_size(size_t memory_reservation_bytes) { |
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67 const size_t memory_commit_block_size_bytes = memory_reservation_bytes / 10; |
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68 assert(memory_commit_block_size_bytes >= (size_t)3*M, "invariant"); |
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69 return memory_commit_block_size_bytes; |
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70 } |
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71 |
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72 static void log_edge_queue_summary(const EdgeQueue& edge_queue) { |
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73 log_trace(jfr, system)("EdgeQueue reserved size total: " SIZE_FORMAT " [KB]", edge_queue.reserved_size() / K); |
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74 log_trace(jfr, system)("EdgeQueue edges total: " SIZE_FORMAT, edge_queue.top()); |
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75 log_trace(jfr, system)("EdgeQueue liveset total: " SIZE_FORMAT " [KB]", edge_queue.live_set() / K); |
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76 if (edge_queue.reserved_size() > 0) { |
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77 log_trace(jfr, system)("EdgeQueue commit reserve ratio: %f\n", |
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78 ((double)edge_queue.live_set() / (double)edge_queue.reserved_size())); |
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79 } |
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80 } |
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81 |
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82 void PathToGcRootsOperation::doit() { |
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83 assert(SafepointSynchronize::is_at_safepoint(), "invariant"); |
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84 assert(_cutoff_ticks > 0, "invariant"); |
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85 |
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86 // The bitset used for marking is dimensioned as a function of the heap size |
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87 const MemRegion heap_region = Universe::heap()->reserved_region(); |
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88 BitSet mark_bits(heap_region); |
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89 |
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90 // The edge queue is dimensioned as a fraction of the heap size |
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91 const size_t edge_queue_reservation_size = edge_queue_memory_reservation(heap_region); |
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92 EdgeQueue edge_queue(edge_queue_reservation_size, edge_queue_memory_commit_size(edge_queue_reservation_size)); |
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93 |
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94 // The initialize() routines will attempt to reserve and allocate backing storage memory. |
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95 // Failure to accommodate will render root chain processing impossible. |
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96 // As a fallback on failure, just write out the existing samples, flat, without chains. |
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97 if (!(mark_bits.initialize() && edge_queue.initialize())) { |
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98 log_warning(jfr)("Unable to allocate memory for root chain processing"); |
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99 return; |
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100 } |
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101 |
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102 // Save the original markWord for the potential leak objects, |
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103 // to be restored on function exit |
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104 ObjectSampleMarker marker; |
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105 if (ObjectSampleCheckpoint::save_mark_words(_sampler, marker, _emit_all) == 0) { |
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106 // no valid samples to process |
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107 return; |
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108 } |
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109 |
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110 // Necessary condition for attempting a root set iteration |
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111 Universe::heap()->ensure_parsability(false); |
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112 |
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113 BFSClosure bfs(&edge_queue, _edge_store, &mark_bits); |
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114 RootSetClosure<BFSClosure> roots(&bfs); |
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115 |
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116 GranularTimer::start(_cutoff_ticks, 1000000); |
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117 roots.process(); |
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118 if (edge_queue.is_full()) { |
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119 // Pathological case where roots don't fit in queue |
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120 // Do a depth-first search, but mark roots first |
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121 // to avoid walking sideways over roots |
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122 DFSClosure::find_leaks_from_root_set(_edge_store, &mark_bits); |
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123 } else { |
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124 bfs.process(); |
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125 } |
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126 GranularTimer::stop(); |
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127 log_edge_queue_summary(edge_queue); |
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128 |
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129 // Emit old objects including their reference chains as events |
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130 EventEmitter emitter(GranularTimer::start_time(), GranularTimer::end_time()); |
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131 emitter.write_events(_sampler, _edge_store, _emit_all); |
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132 } |