1 /* 2 * Copyright (c) 2011, 2016, 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 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 _conc_collection_counters(NULL), 80 _old_collection_counters(NULL), 81 _old_space_counters(NULL), 82 _young_collection_counters(NULL), 83 _eden_counters(NULL), 84 _from_counters(NULL), 85 _to_counters(NULL), 86 87 _overall_reserved(0), 88 _overall_committed(0), _overall_used(0), 89 _young_region_num(0), 90 _young_gen_committed(0), 91 _eden_committed(0), _eden_used(0), 92 _survivor_committed(0), _survivor_used(0), 93 _old_committed(0), _old_used(0) { 94 95 _overall_reserved = g1h->max_capacity(); 96 recalculate_sizes(); 97 98 // Counters for GC collections 99 // 100 // name "collector.0". In a generational collector this would be the 101 // young generation collection. 102 _incremental_collection_counters = 103 new CollectorCounters("G1 incremental collections", 0); 104 // name "collector.1". In a generational collector this would be the 105 // old generation collection. 106 _full_collection_counters = 107 new CollectorCounters("G1 stop-the-world full collections", 1); 108 // name "collector.2". STW phases as part of a concurrent collection. 109 _conc_collection_counters = 110 new CollectorCounters("G1 stop-the-world phases", 2); 111 112 // timer sampling for all counters supporting sampling only update the 113 // used value. See the take_sample() method. G1 requires both used and 114 // capacity updated so sampling is not currently used. It might 115 // be sufficient to update all counters in take_sample() even though 116 // take_sample() only returns "used". When sampling was used, there 117 // were some anomolous values emitted which may have been the consequence 118 // of not updating all values simultaneously (i.e., see the calculation done 119 // in eden_space_used(), is it possible that the values used to 120 // calculate either eden_used or survivor_used are being updated by 121 // the collector when the sample is being done?). 122 const bool sampled = false; 123 124 // "Generation" and "Space" counters. 125 // 126 // name "generation.1" This is logically the old generation in 127 // generational GC terms. The "1, 1" parameters are for 128 // the n-th generation (=1) with 1 space. 129 // Counters are created from minCapacity, maxCapacity, and capacity 130 _old_collection_counters = new G1OldGenerationCounters(this, "old"); 131 132 // name "generation.1.space.0" 133 // Counters are created from maxCapacity, capacity, initCapacity, 134 // and used. 135 _old_space_counters = new HSpaceCounters("space", 0 /* ordinal */, 136 pad_capacity(overall_reserved()) /* max_capacity */, 137 pad_capacity(old_space_committed()) /* init_capacity */, 138 _old_collection_counters); 139 140 // Young collection set 141 // name "generation.0". This is logically the young generation. 142 // The "0, 3" are parameters for the n-th generation (=0) with 3 spaces. 143 // See _old_collection_counters for additional counters 144 _young_collection_counters = new G1YoungGenerationCounters(this, "young"); 145 146 // name "generation.0.space.0" 147 // See _old_space_counters for additional counters 148 _eden_counters = new HSpaceCounters("eden", 0 /* ordinal */, 149 pad_capacity(overall_reserved()) /* max_capacity */, 150 pad_capacity(eden_space_committed()) /* init_capacity */, 151 _young_collection_counters); 152 153 // name "generation.0.space.1" 154 // See _old_space_counters for additional counters 155 // Set the arguments to indicate that this survivor space is not used. 156 _from_counters = new HSpaceCounters("s0", 1 /* ordinal */, 157 pad_capacity(0) /* max_capacity */, 158 pad_capacity(0) /* init_capacity */, 159 _young_collection_counters); 160 161 // name "generation.0.space.2" 162 // See _old_space_counters for additional counters 163 _to_counters = new HSpaceCounters("s1", 2 /* ordinal */, 164 pad_capacity(overall_reserved()) /* max_capacity */, 165 pad_capacity(survivor_space_committed()) /* init_capacity */, 166 _young_collection_counters); 167 168 if (UsePerfData) { 169 // Given that this survivor space is not used, we update it here 170 // once to reflect that its used space is 0 so that we don't have to 171 // worry about updating it again later. 172 _from_counters->update_used(0); 173 } 174 } 175 176 void G1MonitoringSupport::recalculate_sizes() { 177 G1CollectedHeap* g1 = g1h(); 178 179 // Recalculate all the sizes from scratch. We assume that this is 180 // called at a point where no concurrent updates to the various 181 // values we read here are possible (i.e., at a STW phase at the end 182 // of a GC). 183 184 uint young_list_length = g1->young_regions_count(); 185 uint survivor_list_length = g1->survivor_regions_count(); 186 assert(young_list_length >= survivor_list_length, "invariant"); 187 uint eden_list_length = young_list_length - survivor_list_length; 188 // Max length includes any potential extensions to the young gen 189 // we'll do when the GC locker is active. 190 uint young_list_max_length = g1->g1_policy()->young_list_max_length(); 191 assert(young_list_max_length >= survivor_list_length, "invariant"); 192 uint eden_list_max_length = young_list_max_length - survivor_list_length; 193 194 _overall_used = g1->used_unlocked(); 195 _eden_used = (size_t) eden_list_length * HeapRegion::GrainBytes; 196 _survivor_used = (size_t) survivor_list_length * HeapRegion::GrainBytes; 197 _young_region_num = young_list_length; 198 _old_used = subtract_up_to_zero(_overall_used, _eden_used + _survivor_used); 199 200 // First calculate the committed sizes that can be calculated independently. 201 _survivor_committed = _survivor_used; 202 _old_committed = HeapRegion::align_up_to_region_byte_size(_old_used); 203 204 // Next, start with the overall committed size. 205 _overall_committed = g1->capacity(); 206 size_t committed = _overall_committed; 207 208 // Remove the committed size we have calculated so far (for the 209 // survivor and old space). 210 assert(committed >= (_survivor_committed + _old_committed), "sanity"); 211 committed -= _survivor_committed + _old_committed; 212 213 // Next, calculate and remove the committed size for the eden. 214 _eden_committed = (size_t) eden_list_max_length * HeapRegion::GrainBytes; 215 // Somewhat defensive: be robust in case there are inaccuracies in 216 // the calculations 217 _eden_committed = MIN2(_eden_committed, committed); 218 committed -= _eden_committed; 219 220 // Finally, give the rest to the old space... 221 _old_committed += committed; 222 // ..and calculate the young gen committed. 223 _young_gen_committed = _eden_committed + _survivor_committed; 224 225 assert(_overall_committed == 226 (_eden_committed + _survivor_committed + _old_committed), 227 "the committed sizes should add up"); 228 // Somewhat defensive: cap the eden used size to make sure it 229 // never exceeds the committed size. 230 _eden_used = MIN2(_eden_used, _eden_committed); 231 // _survivor_committed and _old_committed are calculated in terms of 232 // the corresponding _*_used value, so the next two conditions 233 // should hold. 234 assert(_survivor_used <= _survivor_committed, "post-condition"); 235 assert(_old_used <= _old_committed, "post-condition"); 236 } 237 238 void G1MonitoringSupport::recalculate_eden_size() { 239 G1CollectedHeap* g1 = g1h(); 240 241 // When a new eden region is allocated, only the eden_used size is 242 // affected (since we have recalculated everything else at the last GC). 243 244 uint young_region_num = g1h()->young_regions_count(); 245 if (young_region_num > _young_region_num) { 246 uint diff = young_region_num - _young_region_num; 247 _eden_used += (size_t) diff * HeapRegion::GrainBytes; 248 // Somewhat defensive: cap the eden used size to make sure it 249 // never exceeds the committed size. 250 _eden_used = MIN2(_eden_used, _eden_committed); 251 _young_region_num = young_region_num; 252 } 253 } 254 255 void G1MonitoringSupport::update_sizes() { 256 recalculate_sizes(); 257 if (UsePerfData) { 258 eden_counters()->update_capacity(pad_capacity(eden_space_committed())); 259 eden_counters()->update_used(eden_space_used()); 260 // only the to survivor space (s1) is active, so we don't need to 261 // update the counters for the from survivor space (s0) 262 to_counters()->update_capacity(pad_capacity(survivor_space_committed())); 263 to_counters()->update_used(survivor_space_used()); 264 old_space_counters()->update_capacity(pad_capacity(old_space_committed())); 265 old_space_counters()->update_used(old_space_used()); 266 old_collection_counters()->update_all(); 267 young_collection_counters()->update_all(); 268 MetaspaceCounters::update_performance_counters(); 269 CompressedClassSpaceCounters::update_performance_counters(); 270 } 271 } 272 273 void G1MonitoringSupport::update_eden_size() { 274 recalculate_eden_size(); 275 if (UsePerfData) { 276 eden_counters()->update_used(eden_space_used()); 277 } 278 }