1 /* 2 * Copyright (c) 2003, 2012, 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/parallelScavengeHeap.hpp" 29 30 // If boundary moving is being used, create the young gen and old 31 // gen with ASPSYoungGen and ASPSOldGen, respectively. Revert to 32 // the old behavior otherwise (with PSYoungGen and PSOldGen). 33 34 AdjoiningGenerations::AdjoiningGenerations(ReservedSpace old_young_rs, 35 size_t init_low_byte_size, 36 size_t min_low_byte_size, 37 size_t max_low_byte_size, 38 size_t init_high_byte_size, 39 size_t min_high_byte_size, 40 size_t max_high_byte_size, 41 size_t alignment) : 42 _virtual_spaces(old_young_rs, min_low_byte_size, 43 min_high_byte_size, alignment) { 44 assert(min_low_byte_size <= init_low_byte_size && 45 init_low_byte_size <= max_low_byte_size, "Parameter check"); 46 assert(min_high_byte_size <= init_high_byte_size && 47 init_high_byte_size <= max_high_byte_size, "Parameter check"); 48 // Create the generations differently based on the option to 49 // move the boundary. 50 if (UseAdaptiveGCBoundary) { 51 // Initialize the adjoining virtual spaces. Then pass the 52 // a virtual to each generation for initialization of the 53 // generation. 54 55 // Does the actual creation of the virtual spaces 56 _virtual_spaces.initialize(max_low_byte_size, 57 init_low_byte_size, 58 init_high_byte_size); 59 60 // Place the young gen at the high end. Passes in the virtual space. 61 _young_gen = new ASPSYoungGen(_virtual_spaces.high(), 62 _virtual_spaces.high()->committed_size(), 63 min_high_byte_size, 64 _virtual_spaces.high_byte_size_limit()); 65 66 // Place the old gen at the low end. Passes in the virtual space. 67 _old_gen = new ASPSOldGen(_virtual_spaces.low(), 68 _virtual_spaces.low()->committed_size(), 69 min_low_byte_size, 70 _virtual_spaces.low_byte_size_limit(), 71 "old", 1); 72 73 young_gen()->initialize_work(); 74 assert(young_gen()->reserved().byte_size() <= young_gen()->gen_size_limit(), 75 "Consistency check"); 76 assert(old_young_rs.size() >= young_gen()->gen_size_limit(), 77 "Consistency check"); 78 79 old_gen()->initialize_work("old", 1); 80 assert(old_gen()->reserved().byte_size() <= old_gen()->gen_size_limit(), 81 "Consistency check"); 82 assert(old_young_rs.size() >= old_gen()->gen_size_limit(), 83 "Consistency check"); 84 } else { 85 86 // Layout the reserved space for the generations. 87 ReservedSpace old_rs = 88 virtual_spaces()->reserved_space().first_part(max_low_byte_size); 89 ReservedSpace heap_rs = 90 virtual_spaces()->reserved_space().last_part(max_low_byte_size); 91 ReservedSpace young_rs = heap_rs.first_part(max_high_byte_size); 92 assert(young_rs.size() == heap_rs.size(), "Didn't reserve all of the heap"); 93 94 // Create the generations. Virtual spaces are not passed in. 95 _young_gen = new PSYoungGen(init_high_byte_size, 96 min_high_byte_size, 97 max_high_byte_size); 98 _old_gen = new PSOldGen(init_low_byte_size, 99 min_low_byte_size, 100 max_low_byte_size, 101 "old", 1); 102 103 // The virtual spaces are created by the initialization of the gens. 104 _young_gen->initialize(young_rs, alignment); 105 assert(young_gen()->gen_size_limit() == young_rs.size(), 106 "Consistency check"); 107 _old_gen->initialize(old_rs, alignment, "old", 1); 108 assert(old_gen()->gen_size_limit() == old_rs.size(), "Consistency check"); 109 } 110 } 111 112 size_t AdjoiningGenerations::reserved_byte_size() { 113 return virtual_spaces()->reserved_space().size(); 114 } 115 116 117 // Make checks on the current sizes of the generations and 118 // the constraints on the sizes of the generations. Push 119 // up the boundary within the constraints. A partial 120 // push can occur. 121 void AdjoiningGenerations::request_old_gen_expansion(size_t expand_in_bytes) { 122 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 123 124 assert_lock_strong(ExpandHeap_lock); 125 assert_locked_or_safepoint(Heap_lock); 126 127 // These sizes limit the amount the boundaries can move. Effectively, 128 // the generation says how much it is willing to yield to the other 129 // generation. 130 const size_t young_gen_available = young_gen()->available_for_contraction(); 131 const size_t old_gen_available = old_gen()->available_for_expansion(); 132 const size_t alignment = virtual_spaces()->alignment(); 133 size_t change_in_bytes = MIN3(young_gen_available, 134 old_gen_available, 135 align_size_up_(expand_in_bytes, alignment)); 136 137 if (change_in_bytes == 0) { 138 return; 139 } 140 141 if (TraceAdaptiveGCBoundary) { 142 gclog_or_tty->print_cr("Before expansion of old gen with boundary move"); 143 gclog_or_tty->print_cr(" Requested change: 0x%x Attempted change: 0x%x", 144 expand_in_bytes, change_in_bytes); 145 if (!PrintHeapAtGC) { 146 Universe::print_on(gclog_or_tty); 147 } 148 gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K", 149 old_gen()->max_gen_size()/K); 150 } 151 152 // Move the boundary between the generations up (smaller young gen). 153 if (virtual_spaces()->adjust_boundary_up(change_in_bytes)) { 154 young_gen()->reset_after_change(); 155 old_gen()->reset_after_change(); 156 } 157 158 // The total reserved for the generations should match the sum 159 // of the two even if the boundary is moving. 160 assert(reserved_byte_size() == 161 old_gen()->max_gen_size() + young_gen()->max_size(), 162 "Space is missing"); 163 young_gen()->space_invariants(); 164 old_gen()->space_invariants(); 165 166 if (TraceAdaptiveGCBoundary) { 167 gclog_or_tty->print_cr("After expansion of old gen with boundary move"); 168 if (!PrintHeapAtGC) { 169 Universe::print_on(gclog_or_tty); 170 } 171 gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K", 172 old_gen()->max_gen_size()/K); 173 } 174 } 175 176 // See comments on request_old_gen_expansion() 177 bool AdjoiningGenerations::request_young_gen_expansion(size_t expand_in_bytes) { 178 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 179 180 // If eden is not empty, the boundary can be moved but no advantage 181 // can be made of the move since eden cannot be moved. 182 if (!young_gen()->eden_space()->is_empty()) { 183 return false; 184 } 185 186 187 bool result = false; 188 const size_t young_gen_available = young_gen()->available_for_expansion(); 189 const size_t old_gen_available = old_gen()->available_for_contraction(); 190 const size_t alignment = virtual_spaces()->alignment(); 191 size_t change_in_bytes = MIN3(young_gen_available, 192 old_gen_available, 193 align_size_up_(expand_in_bytes, alignment)); 194 195 if (change_in_bytes == 0) { 196 return false; 197 } 198 199 if (TraceAdaptiveGCBoundary) { 200 gclog_or_tty->print_cr("Before expansion of young gen with boundary move"); 201 gclog_or_tty->print_cr(" Requested change: 0x%x Attempted change: 0x%x", 202 expand_in_bytes, change_in_bytes); 203 if (!PrintHeapAtGC) { 204 Universe::print_on(gclog_or_tty); 205 } 206 gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K", 207 young_gen()->max_size()/K); 208 } 209 210 // Move the boundary between the generations down (smaller old gen). 211 MutexLocker x(ExpandHeap_lock); 212 if (virtual_spaces()->adjust_boundary_down(change_in_bytes)) { 213 young_gen()->reset_after_change(); 214 old_gen()->reset_after_change(); 215 result = true; 216 } 217 218 // The total reserved for the generations should match the sum 219 // of the two even if the boundary is moving. 220 assert(reserved_byte_size() == 221 old_gen()->max_gen_size() + young_gen()->max_size(), 222 "Space is missing"); 223 young_gen()->space_invariants(); 224 old_gen()->space_invariants(); 225 226 if (TraceAdaptiveGCBoundary) { 227 gclog_or_tty->print_cr("After expansion of young gen with boundary move"); 228 if (!PrintHeapAtGC) { 229 Universe::print_on(gclog_or_tty); 230 } 231 gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K", 232 young_gen()->max_size()/K); 233 } 234 235 return result; 236 } 237 238 // Additional space is needed in the old generation. Try to move the boundary 239 // up to meet the need. Moves boundary up only 240 void AdjoiningGenerations::adjust_boundary_for_old_gen_needs( 241 size_t desired_free_space) { 242 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 243 244 // Stress testing. 245 if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 1) { 246 MutexLocker x(ExpandHeap_lock); 247 request_old_gen_expansion(virtual_spaces()->alignment() * 3 / 2); 248 } 249 250 // Expand only if the entire generation is already committed. 251 if (old_gen()->virtual_space()->uncommitted_size() == 0) { 252 if (old_gen()->free_in_bytes() < desired_free_space) { 253 MutexLocker x(ExpandHeap_lock); 254 request_old_gen_expansion(desired_free_space); 255 } 256 } 257 } 258 259 // See comment on adjust_boundary_for_old_gen_needss(). 260 // Adjust boundary down only. 261 void AdjoiningGenerations::adjust_boundary_for_young_gen_needs(size_t eden_size, 262 size_t survivor_size) { 263 264 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 265 266 // Stress testing. 267 if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 0) { 268 request_young_gen_expansion(virtual_spaces()->alignment() * 3 / 2); 269 eden_size = young_gen()->eden_space()->capacity_in_bytes(); 270 } 271 272 // Expand only if the entire generation is already committed. 273 if (young_gen()->virtual_space()->uncommitted_size() == 0) { 274 size_t desired_size = eden_size + 2 * survivor_size; 275 const size_t committed = young_gen()->virtual_space()->committed_size(); 276 if (desired_size > committed) { 277 request_young_gen_expansion(desired_size - committed); 278 } 279 } 280 }