1 /* 2 * Copyright (c) 2003, 2013, 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/parallelScavenge/adjoiningGenerations.hpp" 27 #include "gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp" 28 #include "gc_implementation/parallelScavenge/generationSizer.hpp" 29 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp" 30 31 // If boundary moving is being used, create the young gen and old 32 // gen with ASPSYoungGen and ASPSOldGen, respectively. Revert to 33 // the old behavior otherwise (with PSYoungGen and PSOldGen). 34 35 AdjoiningGenerations::AdjoiningGenerations(ReservedSpace old_young_rs, 36 GenerationSizer* policy, 37 size_t alignment) : 38 _virtual_spaces(old_young_rs, policy->min_gen1_size(), 39 policy->min_gen0_size(), alignment) { 40 size_t init_low_byte_size = policy->initial_gen1_size(); 41 size_t min_low_byte_size = policy->min_gen1_size(); 42 size_t max_low_byte_size = policy->max_gen1_size(); 43 size_t init_high_byte_size = policy->initial_gen0_size(); 44 size_t min_high_byte_size = policy->min_gen0_size(); 45 size_t max_high_byte_size = policy->max_gen0_size(); 46 47 assert(min_low_byte_size <= init_low_byte_size && 48 init_low_byte_size <= max_low_byte_size, "Parameter check"); 49 assert(min_high_byte_size <= init_high_byte_size && 50 init_high_byte_size <= max_high_byte_size, "Parameter check"); 51 // Create the generations differently based on the option to 52 // move the boundary. 53 if (UseAdaptiveGCBoundary) { 54 // Initialize the adjoining virtual spaces. Then pass the 55 // a virtual to each generation for initialization of the 56 // generation. 57 58 // Does the actual creation of the virtual spaces 59 _virtual_spaces.initialize(max_low_byte_size, 60 init_low_byte_size, 61 init_high_byte_size); 62 63 // Place the young gen at the high end. Passes in the virtual space. 64 _young_gen = new ASPSYoungGen(_virtual_spaces.high(), 65 _virtual_spaces.high()->committed_size(), 66 min_high_byte_size, 67 _virtual_spaces.high_byte_size_limit()); 68 69 // Place the old gen at the low end. Passes in the virtual space. 70 _old_gen = new ASPSOldGen(_virtual_spaces.low(), 71 _virtual_spaces.low()->committed_size(), 72 min_low_byte_size, 73 _virtual_spaces.low_byte_size_limit(), 74 "old", 1); 75 76 young_gen()->initialize_work(); 77 assert(young_gen()->reserved().byte_size() <= young_gen()->gen_size_limit(), 78 "Consistency check"); 79 assert(old_young_rs.size() >= young_gen()->gen_size_limit(), 80 "Consistency check"); 81 82 old_gen()->initialize_work("old", 1); 83 assert(old_gen()->reserved().byte_size() <= old_gen()->gen_size_limit(), 84 "Consistency check"); 85 assert(old_young_rs.size() >= old_gen()->gen_size_limit(), 86 "Consistency check"); 87 } else { 88 89 // Layout the reserved space for the generations. 90 ReservedSpace old_rs = 91 virtual_spaces()->reserved_space().first_part(max_low_byte_size); 92 ReservedSpace heap_rs = 93 virtual_spaces()->reserved_space().last_part(max_low_byte_size); 94 ReservedSpace young_rs = heap_rs.first_part(max_high_byte_size); 95 assert(young_rs.size() == heap_rs.size(), "Didn't reserve all of the heap"); 96 97 // Create the generations. Virtual spaces are not passed in. 98 _young_gen = new PSYoungGen(init_high_byte_size, 99 min_high_byte_size, 100 max_high_byte_size); 101 _old_gen = new PSOldGen(init_low_byte_size, 102 min_low_byte_size, 103 max_low_byte_size, 104 "old", 1); 105 106 // The virtual spaces are created by the initialization of the gens. 107 _young_gen->initialize(young_rs, alignment); 108 assert(young_gen()->gen_size_limit() == young_rs.size(), 109 "Consistency check"); 110 _old_gen->initialize(old_rs, alignment, "old", 1); 111 assert(old_gen()->gen_size_limit() == old_rs.size(), "Consistency check"); 112 } 113 } 114 115 size_t AdjoiningGenerations::reserved_byte_size() { 116 return virtual_spaces()->reserved_space().size(); 117 } 118 119 120 // Make checks on the current sizes of the generations and 121 // the constraints on the sizes of the generations. Push 122 // up the boundary within the constraints. A partial 123 // push can occur. 124 void AdjoiningGenerations::request_old_gen_expansion(size_t expand_in_bytes) { 125 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 126 127 assert_lock_strong(ExpandHeap_lock); 128 assert_locked_or_safepoint(Heap_lock); 129 130 // These sizes limit the amount the boundaries can move. Effectively, 131 // the generation says how much it is willing to yield to the other 132 // generation. 133 const size_t young_gen_available = young_gen()->available_for_contraction(); 134 const size_t old_gen_available = old_gen()->available_for_expansion(); 135 const size_t alignment = virtual_spaces()->alignment(); 136 size_t change_in_bytes = MIN3(young_gen_available, 137 old_gen_available, 138 align_size_up_(expand_in_bytes, alignment)); 139 140 if (change_in_bytes == 0) { 141 return; 142 } 143 144 if (TraceAdaptiveGCBoundary) { 145 gclog_or_tty->print_cr("Before expansion of old gen with boundary move"); 146 gclog_or_tty->print_cr(" Requested change: " SIZE_FORMAT_HEX 147 " Attempted change: " SIZE_FORMAT_HEX, 148 expand_in_bytes, change_in_bytes); 149 if (!PrintHeapAtGC) { 150 Universe::print_on(gclog_or_tty); 151 } 152 gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K", 153 old_gen()->max_gen_size()/K); 154 } 155 156 // Move the boundary between the generations up (smaller young gen). 157 if (virtual_spaces()->adjust_boundary_up(change_in_bytes)) { 158 young_gen()->reset_after_change(); 159 old_gen()->reset_after_change(); 160 } 161 162 // The total reserved for the generations should match the sum 163 // of the two even if the boundary is moving. 164 assert(reserved_byte_size() == 165 old_gen()->max_gen_size() + young_gen()->max_size(), 166 "Space is missing"); 167 young_gen()->space_invariants(); 168 old_gen()->space_invariants(); 169 170 if (TraceAdaptiveGCBoundary) { 171 gclog_or_tty->print_cr("After expansion of old gen with boundary move"); 172 if (!PrintHeapAtGC) { 173 Universe::print_on(gclog_or_tty); 174 } 175 gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K", 176 old_gen()->max_gen_size()/K); 177 } 178 } 179 180 // See comments on request_old_gen_expansion() 181 bool AdjoiningGenerations::request_young_gen_expansion(size_t expand_in_bytes) { 182 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 183 184 // If eden is not empty, the boundary can be moved but no advantage 185 // can be made of the move since eden cannot be moved. 186 if (!young_gen()->eden_space()->is_empty()) { 187 return false; 188 } 189 190 191 bool result = false; 192 const size_t young_gen_available = young_gen()->available_for_expansion(); 193 const size_t old_gen_available = old_gen()->available_for_contraction(); 194 const size_t alignment = virtual_spaces()->alignment(); 195 size_t change_in_bytes = MIN3(young_gen_available, 196 old_gen_available, 197 align_size_up_(expand_in_bytes, alignment)); 198 199 if (change_in_bytes == 0) { 200 return false; 201 } 202 203 if (TraceAdaptiveGCBoundary) { 204 gclog_or_tty->print_cr("Before expansion of young gen with boundary move"); 205 gclog_or_tty->print_cr(" Requested change: " SIZE_FORMAT_HEX " Attempted change: " SIZE_FORMAT_HEX, 206 expand_in_bytes, change_in_bytes); 207 if (!PrintHeapAtGC) { 208 Universe::print_on(gclog_or_tty); 209 } 210 gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K", 211 young_gen()->max_size()/K); 212 } 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 if (TraceAdaptiveGCBoundary) { 231 gclog_or_tty->print_cr("After expansion of young gen with boundary move"); 232 if (!PrintHeapAtGC) { 233 Universe::print_on(gclog_or_tty); 234 } 235 gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K", 236 young_gen()->max_size()/K); 237 } 238 239 return result; 240 } 241 242 // Additional space is needed in the old generation. Try to move the boundary 243 // up to meet the need. Moves boundary up only 244 void AdjoiningGenerations::adjust_boundary_for_old_gen_needs( 245 size_t desired_free_space) { 246 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 247 248 // Stress testing. 249 if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 1) { 250 MutexLocker x(ExpandHeap_lock); 251 request_old_gen_expansion(virtual_spaces()->alignment() * 3 / 2); 252 } 253 254 // Expand only if the entire generation is already committed. 255 if (old_gen()->virtual_space()->uncommitted_size() == 0) { 256 if (old_gen()->free_in_bytes() < desired_free_space) { 257 MutexLocker x(ExpandHeap_lock); 258 request_old_gen_expansion(desired_free_space); 259 } 260 } 261 } 262 263 // See comment on adjust_boundary_for_old_gen_needss(). 264 // Adjust boundary down only. 265 void AdjoiningGenerations::adjust_boundary_for_young_gen_needs(size_t eden_size, 266 size_t survivor_size) { 267 268 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 269 270 // Stress testing. 271 if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 0) { 272 request_young_gen_expansion(virtual_spaces()->alignment() * 3 / 2); 273 eden_size = young_gen()->eden_space()->capacity_in_bytes(); 274 } 275 276 // Expand only if the entire generation is already committed. 277 if (young_gen()->virtual_space()->uncommitted_size() == 0) { 278 size_t desired_size = eden_size + 2 * survivor_size; 279 const size_t committed = young_gen()->virtual_space()->committed_size(); 280 if (desired_size > committed) { 281 request_young_gen_expansion(desired_size - committed); 282 } 283 } 284 }