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