1 /* 2 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. 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 #include "gc_implementation/g1/g1MonitoringSupport.hpp" 27 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" 28 #include "gc_implementation/g1/g1CollectorPolicy.hpp" 29 30 G1GenerationCounters::G1GenerationCounters(G1MonitoringSupport* g1mm, 31 const char* name, 32 int ordinal, int spaces, 33 size_t min_capacity, 34 size_t max_capacity, 35 size_t curr_capacity) 36 : GenerationCounters(name, ordinal, spaces, min_capacity, 37 max_capacity, curr_capacity), _g1mm(g1mm) { } 38 39 // We pad the capacity three times given that the young generation 40 // contains three spaces (eden and two survivors). 41 G1YoungGenerationCounters::G1YoungGenerationCounters(G1MonitoringSupport* g1mm, 42 const char* name) 43 : G1GenerationCounters(g1mm, name, 0 /* ordinal */, 3 /* spaces */, 44 G1MonitoringSupport::pad_capacity(0, 3) /* min_capacity */, 45 G1MonitoringSupport::pad_capacity(g1mm->young_gen_max(), 3), 46 G1MonitoringSupport::pad_capacity(0, 3) /* curr_capacity */) { 47 if (UsePerfData) { 48 update_all(); 49 } 50 } 51 52 G1OldGenerationCounters::G1OldGenerationCounters(G1MonitoringSupport* g1mm, 53 const char* name) 54 : G1GenerationCounters(g1mm, name, 1 /* ordinal */, 1 /* spaces */, 55 G1MonitoringSupport::pad_capacity(0) /* min_capacity */, 56 G1MonitoringSupport::pad_capacity(g1mm->old_gen_max()), 57 G1MonitoringSupport::pad_capacity(0) /* curr_capacity */) { 58 if (UsePerfData) { 59 update_all(); 60 } 61 } 62 63 void G1YoungGenerationCounters::update_all() { 64 size_t committed = 65 G1MonitoringSupport::pad_capacity(_g1mm->young_gen_committed(), 3); 66 _current_size->set_value(committed); 67 } 68 69 void G1OldGenerationCounters::update_all() { 70 size_t committed = 71 G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed()); 72 _current_size->set_value(committed); 73 } 74 75 G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) : 76 _g1h(g1h), 77 _incremental_collection_counters(NULL), 78 _full_collection_counters(NULL), 79 _old_collection_counters(NULL), 80 _old_space_counters(NULL), 81 _young_collection_counters(NULL), 82 _eden_counters(NULL), 83 _from_counters(NULL), 84 _to_counters(NULL), 85 86 _overall_reserved(0), 87 _overall_committed(0), _overall_used(0), 88 _young_region_num(0), 89 _young_gen_committed(0), 90 _eden_committed(0), _eden_used(0), 91 _survivor_committed(0), _survivor_used(0), 92 _old_committed(0), _old_used(0) { 93 94 _overall_reserved = g1h->max_capacity(); 95 recalculate_sizes(); 96 97 // Counters for GC collections 98 // 99 // name "collector.0". In a generational collector this would be the 100 // young generation collection. 101 _incremental_collection_counters = 102 new CollectorCounters("G1 incremental collections", 0); 103 // name "collector.1". In a generational collector this would be the 104 // old generation collection. 105 _full_collection_counters = 106 new CollectorCounters("G1 stop-the-world full collections", 1); 107 108 // timer sampling for all counters supporting sampling only update the 109 // used value. See the take_sample() method. G1 requires both used and 110 // capacity updated so sampling is not currently used. It might 111 // be sufficient to update all counters in take_sample() even though 112 // take_sample() only returns "used". When sampling was used, there 113 // were some anomolous values emitted which may have been the consequence 114 // of not updating all values simultaneously (i.e., see the calculation done 115 // in eden_space_used(), is it possible that the values used to 116 // calculate either eden_used or survivor_used are being updated by 117 // the collector when the sample is being done?). 118 const bool sampled = false; 119 120 // "Generation" and "Space" counters. 121 // 122 // name "generation.1" This is logically the old generation in 123 // generational GC terms. The "1, 1" parameters are for 124 // the n-th generation (=1) with 1 space. 125 // Counters are created from minCapacity, maxCapacity, and capacity 126 _old_collection_counters = new G1OldGenerationCounters(this, "old"); 127 128 // name "generation.1.space.0" 129 // Counters are created from maxCapacity, capacity, initCapacity, 130 // and used. 131 _old_space_counters = new HSpaceCounters("space", 0 /* ordinal */, 132 pad_capacity(overall_reserved()) /* max_capacity */, 133 pad_capacity(old_space_committed()) /* init_capacity */, 134 _old_collection_counters); 135 136 // Young collection set 137 // name "generation.0". This is logically the young generation. 138 // The "0, 3" are parameters for the n-th generation (=0) with 3 spaces. 139 // See _old_collection_counters for additional counters 140 _young_collection_counters = new G1YoungGenerationCounters(this, "young"); 141 142 // name "generation.0.space.0" 143 // See _old_space_counters for additional counters 144 _eden_counters = new HSpaceCounters("eden", 0 /* ordinal */, 145 pad_capacity(overall_reserved()) /* max_capacity */, 146 pad_capacity(eden_space_committed()) /* init_capacity */, 147 _young_collection_counters); 148 149 // name "generation.0.space.1" 150 // See _old_space_counters for additional counters 151 // Set the arguments to indicate that this survivor space is not used. 152 _from_counters = new HSpaceCounters("s0", 1 /* ordinal */, 153 pad_capacity(0) /* max_capacity */, 154 pad_capacity(0) /* init_capacity */, 155 _young_collection_counters); 156 157 // name "generation.0.space.2" 158 // See _old_space_counters for additional counters 159 _to_counters = new HSpaceCounters("s1", 2 /* ordinal */, 160 pad_capacity(overall_reserved()) /* max_capacity */, 161 pad_capacity(survivor_space_committed()) /* init_capacity */, 162 _young_collection_counters); 163 164 if (UsePerfData) { 165 // Given that this survivor space is not used, we update it here 166 // once to reflect that its used space is 0 so that we don't have to 167 // worry about updating it again later. 168 _from_counters->update_used(0); 169 } 170 } 171 172 void G1MonitoringSupport::recalculate_sizes() { 173 G1CollectedHeap* g1 = g1h(); 174 175 // Recalculate all the sizes from scratch. We assume that this is 176 // called at a point where no concurrent updates to the various 177 // values we read here are possible (i.e., at a STW phase at the end 178 // of a GC). 179 180 uint young_list_length = g1->young_list()->length(); 181 uint survivor_list_length = g1->g1_policy()->recorded_survivor_regions(); 182 assert(young_list_length >= survivor_list_length, "invariant"); 183 uint eden_list_length = young_list_length - survivor_list_length; 184 // Max length includes any potential extensions to the young gen 185 // we'll do when the GC locker is active. 186 uint young_list_max_length = g1->g1_policy()->young_list_max_length(); 187 assert(young_list_max_length >= survivor_list_length, "invariant"); 188 uint eden_list_max_length = young_list_max_length - survivor_list_length; 189 190 _overall_used = g1->used_unlocked(); 191 _eden_used = (size_t) eden_list_length * HeapRegion::GrainBytes; 192 _survivor_used = (size_t) survivor_list_length * HeapRegion::GrainBytes; 193 _young_region_num = young_list_length; 194 _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used); 195 196 // First calculate the committed sizes that can be calculated independently. 197 _survivor_committed = _survivor_used; 198 _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used); 199 200 // Next, start with the overall committed size. 201 _overall_committed = g1->capacity(); 202 size_t committed = _overall_committed; 203 204 // Remove the committed size we have calculated so far (for the 205 // survivor and old space). 206 assert(committed >= (_survivor_committed + _old_committed), "sanity"); 207 committed -= _survivor_committed + _old_committed; 208 209 // Next, calculate and remove the committed size for the eden. 210 _eden_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes; 211 // Somewhat defensive: be robust in case there are inaccuracies in 212 // the calculations 213 _eden_committed = MIN2(_eden_committed, committed); 214 committed -= _eden_committed; 215 216 // Finally, give the rest to the old space... 217 _old_committed += committed; 218 // ..and calculate the young gen committed. 219 _young_gen_committed = _eden_committed + _survivor_committed; 220 221 assert(_overall_committed == 222 (_eden_committed + _survivor_committed + _old_committed), 223 "the committed sizes should add up"); 224 // Somewhat defensive: cap the eden used size to make sure it 225 // never exceeds the committed size. 226 _eden_used = MIN2(_eden_used, _eden_committed); 227 // _survivor_committed and _old_committed are calculated in terms of 228 // the corresponding _*_used value, so the next two conditions 229 // should hold. 230 assert(_survivor_used <= _survivor_committed, "post-condition"); 231 assert(_old_used <= _old_committed, "post-condition"); 232 } 233 234 void G1MonitoringSupport::recalculate_eden_size() { 235 G1CollectedHeap* g1 = g1h(); 236 237 // When a new eden region is allocated, only the eden_used size is 238 // affected (since we have recalculated everything else at the last GC). 239 240 uint young_region_num = g1h()->young_list()->length(); 241 if (young_region_num > _young_region_num) { 242 uint diff = young_region_num - _young_region_num; 243 _eden_used += (size_t) diff * HeapRegion::GrainBytes; 244 // Somewhat defensive: cap the eden used size to make sure it 245 // never exceeds the committed size. 246 _eden_used = MIN2(_eden_used, _eden_committed); 247 _young_region_num = young_region_num; 248 } 249 } 250 251 void G1MonitoringSupport::update_sizes() { 252 recalculate_sizes(); 253 if (UsePerfData) { 254 eden_counters()->update_capacity(pad_capacity(eden_space_committed())); 255 eden_counters()->update_used(eden_space_used()); 256 // only the to survivor space (s1) is active, so we don't need to 257 // update the counters for the from survivor space (s0) 258 to_counters()->update_capacity(pad_capacity(survivor_space_committed())); 259 to_counters()->update_used(survivor_space_used()); 260 old_space_counters()->update_capacity(pad_capacity(old_space_committed())); 261 old_space_counters()->update_used(old_space_used()); 262 old_collection_counters()->update_all(); 263 young_collection_counters()->update_all(); 264 MetaspaceCounters::update_performance_counters(); 265 CompressedClassSpaceCounters::update_performance_counters(); 266 } 267 } 268 269 void G1MonitoringSupport::update_eden_size() { 270 recalculate_eden_size(); 271 if (UsePerfData) { 272 eden_counters()->update_used(eden_space_used()); 273 } 274 }