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