1 /* 2 * Copyright (c) 2011, 2018, 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/g1/g1CollectedHeap.inline.hpp" 27 #include "gc/g1/g1MonitoringSupport.hpp" 28 #include "gc/g1/g1Policy.hpp" 29 #include "gc/shared/hSpaceCounters.hpp" 30 31 G1GenerationCounters::G1GenerationCounters(G1MonitoringSupport* g1mm, 32 const char* name, 33 int ordinal, int spaces, 34 size_t min_capacity, 35 size_t max_capacity, 36 size_t curr_capacity) 37 : GenerationCounters(name, ordinal, spaces, min_capacity, 38 max_capacity, curr_capacity), _g1mm(g1mm) { } 39 40 // We pad the capacity three times given that the young generation 41 // contains three spaces (eden and two survivors). 42 G1YoungGenerationCounters::G1YoungGenerationCounters(G1MonitoringSupport* g1mm, 43 const char* name) 44 : G1GenerationCounters(g1mm, name, 0 /* ordinal */, 3 /* spaces */, 45 G1MonitoringSupport::pad_capacity(0, 3) /* min_capacity */, 46 G1MonitoringSupport::pad_capacity(g1mm->young_gen_max(), 3), 47 G1MonitoringSupport::pad_capacity(0, 3) /* curr_capacity */) { 48 if (UsePerfData) { 49 update_all(); 50 } 51 } 52 53 G1OldGenerationCounters::G1OldGenerationCounters(G1MonitoringSupport* g1mm, 54 const char* name) 55 : G1GenerationCounters(g1mm, name, 1 /* ordinal */, 1 /* spaces */, 56 G1MonitoringSupport::pad_capacity(0) /* min_capacity */, 57 G1MonitoringSupport::pad_capacity(g1mm->old_gen_max()), 58 G1MonitoringSupport::pad_capacity(0) /* curr_capacity */) { 59 if (UsePerfData) { 60 update_all(); 61 } 62 } 63 64 void G1YoungGenerationCounters::update_all() { 65 size_t committed = 66 G1MonitoringSupport::pad_capacity(_g1mm->young_gen_committed(), 3); 67 _current_size->set_value(committed); 68 } 69 70 void G1OldGenerationCounters::update_all() { 71 size_t committed = 72 G1MonitoringSupport::pad_capacity(_g1mm->old_gen_committed()); 73 _current_size->set_value(committed); 74 } 75 76 G1MonitoringSupport::G1MonitoringSupport(G1CollectedHeap* g1h) : 77 _g1h(g1h), 78 _incremental_collection_counters(NULL), 79 _full_collection_counters(NULL), 80 _conc_collection_counters(NULL), 81 _old_collection_counters(NULL), 82 _old_space_counters(NULL), 83 _young_collection_counters(NULL), 84 _eden_counters(NULL), 85 _from_counters(NULL), 86 _to_counters(NULL), 87 88 _overall_reserved(0), 89 _overall_committed(0), _overall_used(0), 90 _young_region_num(0), 91 _young_gen_committed(0), 92 _eden_committed(0), _eden_used(0), 93 _survivor_committed(0), _survivor_used(0), 94 _old_committed(0), _old_used(0) { 95 96 _overall_reserved = g1h->max_capacity(); 97 recalculate_sizes(); 98 99 // Counters for GC collections 100 // 101 // name "collector.0". In a generational collector this would be the 102 // young generation collection. 103 _incremental_collection_counters = 104 new CollectorCounters("G1 incremental collections", 0); 105 // name "collector.1". In a generational collector this would be the 106 // old generation collection. 107 _full_collection_counters = 108 new CollectorCounters("G1 stop-the-world full collections", 1); 109 // name "collector.2". In a generational collector this would be the 110 // STW phases in concurrent collection. 111 _conc_collection_counters = 112 new CollectorCounters("G1 stop-the-world phases", 2); 113 114 // timer sampling for all counters supporting sampling only update the 115 // used value. See the take_sample() method. G1 requires both used and 116 // capacity updated so sampling is not currently used. It might 117 // be sufficient to update all counters in take_sample() even though 118 // take_sample() only returns "used". When sampling was used, there 119 // were some anomolous values emitted which may have been the consequence 120 // of not updating all values simultaneously (i.e., see the calculation done 121 // in eden_space_used(), is it possible that the values used to 122 // calculate either eden_used or survivor_used are being updated by 123 // the collector when the sample is being done?). 124 const bool sampled = false; 125 126 // "Generation" and "Space" counters. 127 // 128 // name "generation.1" This is logically the old generation in 129 // generational GC terms. The "1, 1" parameters are for 130 // the n-th generation (=1) with 1 space. 131 // Counters are created from minCapacity, maxCapacity, and capacity 132 _old_collection_counters = new G1OldGenerationCounters(this, "old"); 133 134 // name "generation.1.space.0" 135 // Counters are created from maxCapacity, capacity, initCapacity, 136 // and used. 137 _old_space_counters = new HSpaceCounters(_old_collection_counters->name_space(), 138 "space", 0 /* ordinal */, 139 pad_capacity(overall_reserved()) /* max_capacity */, 140 pad_capacity(old_space_committed()) /* init_capacity */); 141 142 // Young collection set 143 // name "generation.0". This is logically the young generation. 144 // The "0, 3" are parameters for the n-th generation (=0) with 3 spaces. 145 // See _old_collection_counters for additional counters 146 _young_collection_counters = new G1YoungGenerationCounters(this, "young"); 147 148 const char* young_collection_name_space = _young_collection_counters->name_space(); 149 150 // name "generation.0.space.0" 151 // See _old_space_counters for additional counters 152 _eden_counters = new HSpaceCounters(young_collection_name_space, 153 "eden", 0 /* ordinal */, 154 pad_capacity(overall_reserved()) /* max_capacity */, 155 pad_capacity(eden_space_committed()) /* init_capacity */); 156 157 // name "generation.0.space.1" 158 // See _old_space_counters for additional counters 159 // Set the arguments to indicate that this survivor space is not used. 160 _from_counters = new HSpaceCounters(young_collection_name_space, 161 "s0", 1 /* ordinal */, 162 pad_capacity(0) /* max_capacity */, 163 pad_capacity(0) /* init_capacity */); 164 165 // name "generation.0.space.2" 166 // See _old_space_counters for additional counters 167 _to_counters = new HSpaceCounters(young_collection_name_space, 168 "s1", 2 /* ordinal */, 169 pad_capacity(overall_reserved()) /* max_capacity */, 170 pad_capacity(survivor_space_committed()) /* init_capacity */); 171 172 if (UsePerfData) { 173 // Given that this survivor space is not used, we update it here 174 // once to reflect that its used space is 0 so that we don't have to 175 // worry about updating it again later. 176 _from_counters->update_used(0); 177 } 178 } 179 180 void G1MonitoringSupport::recalculate_sizes() { 181 G1CollectedHeap* g1 = g1h(); 182 183 // Recalculate all the sizes from scratch. We assume that this is 184 // called at a point where no concurrent updates to the various 185 // values we read here are possible (i.e., at a STW phase at the end 186 // of a GC). 187 188 uint young_list_length = g1->young_regions_count(); 189 uint survivor_list_length = g1->survivor_regions_count(); 190 assert(young_list_length >= survivor_list_length, "invariant"); 191 uint eden_list_length = young_list_length - survivor_list_length; 192 // Max length includes any potential extensions to the young gen 193 // we'll do when the GC locker is active. 194 uint young_list_max_length = g1->g1_policy()->young_list_max_length(); 195 assert(young_list_max_length >= survivor_list_length, "invariant"); 196 uint eden_list_max_length = young_list_max_length - survivor_list_length; 197 198 _overall_used = g1->used_unlocked(); 199 _eden_used = (size_t) eden_list_length * HeapRegion::GrainBytes; 200 _survivor_used = (size_t) survivor_list_length * HeapRegion::GrainBytes; 201 _young_region_num = young_list_length; 202 _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used); 203 204 // First calculate the committed sizes that can be calculated independently. 205 _survivor_committed = _survivor_used; 206 _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used); 207 208 // Next, start with the overall committed size. 209 _overall_committed = g1->capacity(); 210 size_t committed = _overall_committed; 211 212 // Remove the committed size we have calculated so far (for the 213 // survivor and old space). 214 assert(committed >= (_survivor_committed + _old_committed), "sanity"); 215 committed -= _survivor_committed + _old_committed; 216 217 // Next, calculate and remove the committed size for the eden. 218 _eden_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes; 219 // Somewhat defensive: be robust in case there are inaccuracies in 220 // the calculations 221 _eden_committed = MIN2(_eden_committed, committed); 222 committed -= _eden_committed; 223 224 // Finally, give the rest to the old space... 225 _old_committed += committed; 226 // ..and calculate the young gen committed. 227 _young_gen_committed = _eden_committed + _survivor_committed; 228 229 assert(_overall_committed == 230 (_eden_committed + _survivor_committed + _old_committed), 231 "the committed sizes should add up"); 232 // Somewhat defensive: cap the eden used size to make sure it 233 // never exceeds the committed size. 234 _eden_used = MIN2(_eden_used, _eden_committed); 235 // _survivor_committed and _old_committed are calculated in terms of 236 // the corresponding _*_used value, so the next two conditions 237 // should hold. 238 assert(_survivor_used <= _survivor_committed, "post-condition"); 239 assert(_old_used <= _old_committed, "post-condition"); 240 } 241 242 void G1MonitoringSupport::recalculate_eden_size() { 243 G1CollectedHeap* g1 = g1h(); 244 245 // When a new eden region is allocated, only the eden_used size is 246 // affected (since we have recalculated everything else at the last GC). 247 248 uint young_region_num = g1h()->young_regions_count(); 249 if (young_region_num > _young_region_num) { 250 uint diff = young_region_num - _young_region_num; 251 _eden_used += (size_t) diff * HeapRegion::GrainBytes; 252 // Somewhat defensive: cap the eden used size to make sure it 253 // never exceeds the committed size. 254 _eden_used = MIN2(_eden_used, _eden_committed); 255 _young_region_num = young_region_num; 256 } 257 } 258 259 void G1MonitoringSupport::update_sizes() { 260 recalculate_sizes(); 261 if (UsePerfData) { 262 eden_counters()->update_capacity(pad_capacity(eden_space_committed())); 263 eden_counters()->update_used(eden_space_used()); 264 // only the to survivor space (s1) is active, so we don't need to 265 // update the counters for the from survivor space (s0) 266 to_counters()->update_capacity(pad_capacity(survivor_space_committed())); 267 to_counters()->update_used(survivor_space_used()); 268 old_space_counters()->update_capacity(pad_capacity(old_space_committed())); 269 old_space_counters()->update_used(old_space_used()); 270 old_collection_counters()->update_all(); 271 young_collection_counters()->update_all(); 272 MetaspaceCounters::update_performance_counters(); 273 CompressedClassSpaceCounters::update_performance_counters(); 274 } 275 } 276 277 void G1MonitoringSupport::update_eden_size() { 278 recalculate_eden_size(); 279 if (UsePerfData) { 280 eden_counters()->update_used(eden_space_used()); 281 } 282 } --- EOF ---