1 /* 2 * Copyright (c) 2003, 2015, 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/parallel/adjoiningGenerations.hpp" 27 #include "gc/parallel/adjoiningVirtualSpaces.hpp" 28 #include "gc/parallel/generationSizer.hpp" 29 #include "gc/parallel/parallelScavengeHeap.hpp" 30 #include "logging/log.hpp" 31 #include "logging/logStream.hpp" 32 #include "memory/resourceArea.hpp" 33 #include "utilities/align.hpp" 34 #include "utilities/ostream.hpp" 35 36 // If boundary moving is being used, create the young gen and old 37 // gen with ASPSYoungGen and ASPSOldGen, respectively. Revert to 38 // the old behavior otherwise (with PSYoungGen and PSOldGen). 39 40 AdjoiningGenerations::AdjoiningGenerations(ReservedSpace old_young_rs, 41 GenerationSizer* policy, 42 size_t alignment) : 43 _virtual_spaces(new AdjoiningVirtualSpaces(old_young_rs, policy->min_old_size(), 44 policy->min_young_size(), alignment) ) { 45 size_t init_low_byte_size = policy->initial_old_size(); 46 size_t min_low_byte_size = policy->min_old_size(); 47 size_t max_low_byte_size = policy->max_old_size(); 48 size_t init_high_byte_size = policy->initial_young_size(); 49 size_t min_high_byte_size = policy->min_young_size(); 50 size_t max_high_byte_size = policy->max_young_size(); 51 52 assert(min_low_byte_size <= init_low_byte_size && 53 init_low_byte_size <= max_low_byte_size, "Parameter check"); 54 assert(min_high_byte_size <= init_high_byte_size && 55 init_high_byte_size <= max_high_byte_size, "Parameter check"); 56 // Create the generations differently based on the option to 57 // move the boundary. 58 if (UseAdaptiveGCBoundary) { 59 // Initialize the adjoining virtual spaces. Then pass the 60 // a virtual to each generation for initialization of the 61 // generation. 62 63 // Does the actual creation of the virtual spaces 64 _virtual_spaces->initialize(max_low_byte_size, 65 init_low_byte_size, 66 init_high_byte_size); 67 68 // Place the young gen at the high end. Passes in the virtual space. 69 _young_gen = new ASPSYoungGen(_virtual_spaces->high(), 70 _virtual_spaces->high()->committed_size(), 71 min_high_byte_size, 72 _virtual_spaces->high_byte_size_limit()); 73 74 // Place the old gen at the low end. Passes in the virtual space. 75 _old_gen = new ASPSOldGen(_virtual_spaces->low(), 76 _virtual_spaces->low()->committed_size(), 77 min_low_byte_size, 78 _virtual_spaces->low_byte_size_limit(), 79 "old", 1); 80 81 young_gen()->initialize_work(); 82 assert(young_gen()->reserved().byte_size() <= young_gen()->gen_size_limit(), 83 "Consistency check"); 84 assert(old_young_rs.size() >= young_gen()->gen_size_limit(), 85 "Consistency check"); 86 87 old_gen()->initialize_work("old", 1); 88 assert(old_gen()->reserved().byte_size() <= old_gen()->gen_size_limit(), 89 "Consistency check"); 90 assert(old_young_rs.size() >= old_gen()->gen_size_limit(), 91 "Consistency check"); 92 } else { 93 // Layout the reserved space for the generations. 94 // If OldGen is allocated on nv-dimm, we need to split the reservation (this is required for windows). 95 ReservedSpace old_rs = 96 virtual_spaces()->reserved_space().first_part(max_low_byte_size, AllocateOldGenAt != NULL /* split */); 97 ReservedSpace heap_rs = 98 virtual_spaces()->reserved_space().last_part(max_low_byte_size); 99 ReservedSpace young_rs = heap_rs.first_part(max_high_byte_size); 100 assert(young_rs.size() == heap_rs.size(), "Didn't reserve all of the heap"); 101 102 // Create the generations. Virtual spaces are not passed in. 103 _young_gen = new PSYoungGen(init_high_byte_size, 104 min_high_byte_size, 105 max_high_byte_size); 106 _old_gen = new PSOldGen(init_low_byte_size, 107 min_low_byte_size, 108 max_low_byte_size, 109 "old", 1); 110 111 // The virtual spaces are created by the initialization of the gens. 112 _young_gen->initialize(young_rs, alignment); 113 assert(young_gen()->gen_size_limit() == young_rs.size(), 114 "Consistency check"); 115 _old_gen->initialize(old_rs, alignment, "old", 1); 116 assert(old_gen()->gen_size_limit() == old_rs.size(), "Consistency check"); 117 } 118 } 119 120 AdjoiningGenerations::AdjoiningGenerations() { } 121 122 size_t AdjoiningGenerations::reserved_byte_size() { 123 return virtual_spaces()->reserved_space().size(); 124 } 125 126 void log_before_expansion(bool old, size_t expand_in_bytes, size_t change_in_bytes, size_t max_size) { 127 Log(heap, ergo) log; 128 if (!log.is_debug()) { 129 return; 130 } 131 log.debug("Before expansion of %s gen with boundary move", old ? "old" : "young"); 132 log.debug(" Requested change: " SIZE_FORMAT_HEX " Attempted change: " SIZE_FORMAT_HEX, 133 expand_in_bytes, change_in_bytes); 134 ResourceMark rm; 135 LogStream ls(log.debug()); 136 ParallelScavengeHeap::heap()->print_on(&ls); 137 log.debug(" PS%sGen max size: " SIZE_FORMAT "K", old ? "Old" : "Young", max_size/K); 138 } 139 140 void log_after_expansion(bool old, size_t max_size) { 141 Log(heap, ergo) log; 142 if (!log.is_debug()) { 143 return; 144 } 145 log.debug("After expansion of %s gen with boundary move", old ? "old" : "young"); 146 ResourceMark rm; 147 LogStream ls(log.debug()); 148 ParallelScavengeHeap::heap()->print_on(&ls); 149 log.debug(" PS%sGen max size: " SIZE_FORMAT "K", old ? "Old" : "Young", max_size/K); 150 } 151 152 // Make checks on the current sizes of the generations and 153 // the constraints on the sizes of the generations. Push 154 // up the boundary within the constraints. A partial 155 // push can occur. 156 void AdjoiningGenerations::request_old_gen_expansion(size_t expand_in_bytes) { 157 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 158 159 assert_lock_strong(ExpandHeap_lock); 160 assert_locked_or_safepoint(Heap_lock); 161 162 // These sizes limit the amount the boundaries can move. Effectively, 163 // the generation says how much it is willing to yield to the other 164 // generation. 165 const size_t young_gen_available = young_gen()->available_for_contraction(); 166 const size_t old_gen_available = old_gen()->available_for_expansion(); 167 const size_t alignment = virtual_spaces()->alignment(); 168 size_t change_in_bytes = MIN3(young_gen_available, 169 old_gen_available, 170 align_up(expand_in_bytes, alignment)); 171 172 if (change_in_bytes == 0) { 173 return; 174 } 175 176 log_before_expansion(true, expand_in_bytes, change_in_bytes, old_gen()->max_gen_size()); 177 178 // Move the boundary between the generations up (smaller young gen). 179 if (virtual_spaces()->adjust_boundary_up(change_in_bytes)) { 180 young_gen()->reset_after_change(); 181 old_gen()->reset_after_change(); 182 } 183 184 // The total reserved for the generations should match the sum 185 // of the two even if the boundary is moving. 186 assert(reserved_byte_size() == 187 old_gen()->max_gen_size() + young_gen()->max_size(), 188 "Space is missing"); 189 young_gen()->space_invariants(); 190 old_gen()->space_invariants(); 191 192 log_after_expansion(true, old_gen()->max_gen_size()); 193 } 194 195 // See comments on request_old_gen_expansion() 196 bool AdjoiningGenerations::request_young_gen_expansion(size_t expand_in_bytes) { 197 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 198 199 // If eden is not empty, the boundary can be moved but no advantage 200 // can be made of the move since eden cannot be moved. 201 if (!young_gen()->eden_space()->is_empty()) { 202 return false; 203 } 204 205 206 bool result = false; 207 const size_t young_gen_available = young_gen()->available_for_expansion(); 208 const size_t old_gen_available = old_gen()->available_for_contraction(); 209 const size_t alignment = virtual_spaces()->alignment(); 210 size_t change_in_bytes = MIN3(young_gen_available, 211 old_gen_available, 212 align_up(expand_in_bytes, alignment)); 213 214 if (change_in_bytes == 0) { 215 return false; 216 } 217 218 log_before_expansion(false, expand_in_bytes, change_in_bytes, young_gen()->max_size()); 219 220 // Move the boundary between the generations down (smaller old gen). 221 MutexLocker x(ExpandHeap_lock); 222 if (virtual_spaces()->adjust_boundary_down(change_in_bytes)) { 223 young_gen()->reset_after_change(); 224 old_gen()->reset_after_change(); 225 result = true; 226 } 227 228 // The total reserved for the generations should match the sum 229 // of the two even if the boundary is moving. 230 assert(reserved_byte_size() == 231 old_gen()->max_gen_size() + young_gen()->max_size(), 232 "Space is missing"); 233 young_gen()->space_invariants(); 234 old_gen()->space_invariants(); 235 236 log_after_expansion(false, young_gen()->max_size()); 237 238 return result; 239 } 240 241 // Additional space is needed in the old generation. Try to move the boundary 242 // up to meet the need. Moves boundary up only 243 void AdjoiningGenerations::adjust_boundary_for_old_gen_needs( 244 size_t desired_free_space) { 245 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 246 247 // Stress testing. 248 if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 1) { 249 MutexLocker x(ExpandHeap_lock); 250 request_old_gen_expansion(virtual_spaces()->alignment() * 3 / 2); 251 } 252 253 // Expand only if the entire generation is already committed. 254 if (old_gen()->virtual_space()->uncommitted_size() == 0) { 255 if (old_gen()->free_in_bytes() < desired_free_space) { 256 MutexLocker x(ExpandHeap_lock); 257 request_old_gen_expansion(desired_free_space); 258 } 259 } 260 } 261 262 // See comment on adjust_boundary_for_old_gen_needss(). 263 // Adjust boundary down only. 264 void AdjoiningGenerations::adjust_boundary_for_young_gen_needs(size_t eden_size, 265 size_t survivor_size) { 266 267 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 268 269 // Stress testing. 270 if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 0) { 271 request_young_gen_expansion(virtual_spaces()->alignment() * 3 / 2); 272 eden_size = young_gen()->eden_space()->capacity_in_bytes(); 273 } 274 275 // Expand only if the entire generation is already committed. 276 if (young_gen()->virtual_space()->uncommitted_size() == 0) { 277 size_t desired_size = eden_size + 2 * survivor_size; 278 const size_t committed = young_gen()->virtual_space()->committed_size(); 279 if (desired_size > committed) { 280 request_young_gen_expansion(desired_size - committed); 281 } 282 } 283 }