1 /* 2 * Copyright (c) 2003, 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 "incls/_precompiled.incl" 26 # include "incls/_adjoiningGenerations.cpp.incl" 27 28 // If boundary moving is being used, create the young gen and old 29 // gen with ASPSYoungGen and ASPSOldGen, respectively. Revert to 30 // the old behavior otherwise (with PSYoungGen and PSOldGen). 31 32 AdjoiningGenerations::AdjoiningGenerations(ReservedSpace old_young_rs, 33 size_t init_low_byte_size, 34 size_t min_low_byte_size, 35 size_t max_low_byte_size, 36 size_t init_high_byte_size, 37 size_t min_high_byte_size, 38 size_t max_high_byte_size, 39 size_t alignment) : 40 _virtual_spaces(old_young_rs, min_low_byte_size, 41 min_high_byte_size, alignment) { 42 assert(min_low_byte_size <= init_low_byte_size && 43 init_low_byte_size <= max_low_byte_size, "Parameter check"); 44 assert(min_high_byte_size <= init_high_byte_size && 45 init_high_byte_size <= max_high_byte_size, "Parameter check"); 46 // Create the generations differently based on the option to 47 // move the boundary. 48 if (UseAdaptiveGCBoundary) { 49 // Initialize the adjoining virtual spaces. Then pass the 50 // a virtual to each generation for initialization of the 51 // generation. 52 53 // Does the actual creation of the virtual spaces 54 _virtual_spaces.initialize(max_low_byte_size, 55 init_low_byte_size, 56 init_high_byte_size); 57 58 // Place the young gen at the high end. Passes in the virtual space. 59 _young_gen = new ASPSYoungGen(_virtual_spaces.high(), 60 _virtual_spaces.high()->committed_size(), 61 min_high_byte_size, 62 _virtual_spaces.high_byte_size_limit()); 63 64 // Place the old gen at the low end. Passes in the virtual space. 65 _old_gen = new ASPSOldGen(_virtual_spaces.low(), 66 _virtual_spaces.low()->committed_size(), 67 min_low_byte_size, 68 _virtual_spaces.low_byte_size_limit(), 69 "old", 1); 70 71 young_gen()->initialize_work(); 72 assert(young_gen()->reserved().byte_size() <= young_gen()->gen_size_limit(), 73 "Consistency check"); 74 assert(old_young_rs.size() >= young_gen()->gen_size_limit(), 75 "Consistency check"); 76 77 old_gen()->initialize_work("old", 1); 78 assert(old_gen()->reserved().byte_size() <= old_gen()->gen_size_limit(), 79 "Consistency check"); 80 assert(old_young_rs.size() >= old_gen()->gen_size_limit(), 81 "Consistency check"); 82 } else { 83 84 // Layout the reserved space for the generations. 85 ReservedSpace old_rs = 86 virtual_spaces()->reserved_space().first_part(max_low_byte_size); 87 ReservedSpace heap_rs = 88 virtual_spaces()->reserved_space().last_part(max_low_byte_size); 89 ReservedSpace young_rs = heap_rs.first_part(max_high_byte_size); 90 assert(young_rs.size() == heap_rs.size(), "Didn't reserve all of the heap"); 91 92 // Create the generations. Virtual spaces are not passed in. 93 _young_gen = new PSYoungGen(init_high_byte_size, 94 min_high_byte_size, 95 max_high_byte_size); 96 _old_gen = new PSOldGen(init_low_byte_size, 97 min_low_byte_size, 98 max_low_byte_size, 99 "old", 1); 100 101 // The virtual spaces are created by the initialization of the gens. 102 _young_gen->initialize(young_rs, alignment); 103 assert(young_gen()->gen_size_limit() == young_rs.size(), 104 "Consistency check"); 105 _old_gen->initialize(old_rs, alignment, "old", 1); 106 assert(old_gen()->gen_size_limit() == old_rs.size(), "Consistency check"); 107 } 108 } 109 110 size_t AdjoiningGenerations::reserved_byte_size() { 111 return virtual_spaces()->reserved_space().size(); 112 } 113 114 115 // Make checks on the current sizes of the generations and 116 // the contraints on the sizes of the generations. Push 117 // up the boundary within the contraints. A partial 118 // push can occur. 119 void AdjoiningGenerations::request_old_gen_expansion(size_t expand_in_bytes) { 120 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 121 122 assert_lock_strong(ExpandHeap_lock); 123 assert_locked_or_safepoint(Heap_lock); 124 125 // These sizes limit the amount the boundaries can move. Effectively, 126 // the generation says how much it is willing to yield to the other 127 // generation. 128 const size_t young_gen_available = young_gen()->available_for_contraction(); 129 const size_t old_gen_available = old_gen()->available_for_expansion(); 130 const size_t alignment = virtual_spaces()->alignment(); 131 size_t change_in_bytes = MIN3(young_gen_available, 132 old_gen_available, 133 align_size_up_(expand_in_bytes, alignment)); 134 135 if (change_in_bytes == 0) { 136 return; 137 } 138 139 if (TraceAdaptiveGCBoundary) { 140 gclog_or_tty->print_cr("Before expansion of old gen with boundary move"); 141 gclog_or_tty->print_cr(" Requested change: 0x%x Attempted change: 0x%x", 142 expand_in_bytes, change_in_bytes); 143 if (!PrintHeapAtGC) { 144 Universe::print_on(gclog_or_tty); 145 } 146 gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K", 147 old_gen()->max_gen_size()/K); 148 } 149 150 // Move the boundary between the generations up (smaller young gen). 151 if (virtual_spaces()->adjust_boundary_up(change_in_bytes)) { 152 young_gen()->reset_after_change(); 153 old_gen()->reset_after_change(); 154 } 155 156 // The total reserved for the generations should match the sum 157 // of the two even if the boundary is moving. 158 assert(reserved_byte_size() == 159 old_gen()->max_gen_size() + young_gen()->max_size(), 160 "Space is missing"); 161 young_gen()->space_invariants(); 162 old_gen()->space_invariants(); 163 164 if (TraceAdaptiveGCBoundary) { 165 gclog_or_tty->print_cr("After expansion of old gen with boundary move"); 166 if (!PrintHeapAtGC) { 167 Universe::print_on(gclog_or_tty); 168 } 169 gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K", 170 old_gen()->max_gen_size()/K); 171 } 172 } 173 174 // See comments on request_old_gen_expansion() 175 bool AdjoiningGenerations::request_young_gen_expansion(size_t expand_in_bytes) { 176 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 177 178 // If eden is not empty, the boundary can be moved but no advantage 179 // can be made of the move since eden cannot be moved. 180 if (!young_gen()->eden_space()->is_empty()) { 181 return false; 182 } 183 184 185 bool result = false; 186 const size_t young_gen_available = young_gen()->available_for_expansion(); 187 const size_t old_gen_available = old_gen()->available_for_contraction(); 188 const size_t alignment = virtual_spaces()->alignment(); 189 size_t change_in_bytes = MIN3(young_gen_available, 190 old_gen_available, 191 align_size_up_(expand_in_bytes, alignment)); 192 193 if (change_in_bytes == 0) { 194 return false; 195 } 196 197 if (TraceAdaptiveGCBoundary) { 198 gclog_or_tty->print_cr("Before expansion of young gen with boundary move"); 199 gclog_or_tty->print_cr(" Requested change: 0x%x Attempted change: 0x%x", 200 expand_in_bytes, change_in_bytes); 201 if (!PrintHeapAtGC) { 202 Universe::print_on(gclog_or_tty); 203 } 204 gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K", 205 young_gen()->max_size()/K); 206 } 207 208 // Move the boundary between the generations down (smaller old gen). 209 MutexLocker x(ExpandHeap_lock); 210 if (virtual_spaces()->adjust_boundary_down(change_in_bytes)) { 211 young_gen()->reset_after_change(); 212 old_gen()->reset_after_change(); 213 result = true; 214 } 215 216 // The total reserved for the generations should match the sum 217 // of the two even if the boundary is moving. 218 assert(reserved_byte_size() == 219 old_gen()->max_gen_size() + young_gen()->max_size(), 220 "Space is missing"); 221 young_gen()->space_invariants(); 222 old_gen()->space_invariants(); 223 224 if (TraceAdaptiveGCBoundary) { 225 gclog_or_tty->print_cr("After expansion of young gen with boundary move"); 226 if (!PrintHeapAtGC) { 227 Universe::print_on(gclog_or_tty); 228 } 229 gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K", 230 young_gen()->max_size()/K); 231 } 232 233 return result; 234 } 235 236 // Additional space is needed in the old generation. Try to move the boundary 237 // up to meet the need. Moves boundary up only 238 void AdjoiningGenerations::adjust_boundary_for_old_gen_needs( 239 size_t desired_free_space) { 240 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 241 242 // Stress testing. 243 if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 1) { 244 MutexLocker x(ExpandHeap_lock); 245 request_old_gen_expansion(virtual_spaces()->alignment() * 3 / 2); 246 } 247 248 // Expand only if the entire generation is already committed. 249 if (old_gen()->virtual_space()->uncommitted_size() == 0) { 250 if (old_gen()->free_in_bytes() < desired_free_space) { 251 MutexLocker x(ExpandHeap_lock); 252 request_old_gen_expansion(desired_free_space); 253 } 254 } 255 } 256 257 // See comment on adjust_boundary_for_old_gen_needss(). 258 // Adjust boundary down only. 259 void AdjoiningGenerations::adjust_boundary_for_young_gen_needs(size_t eden_size, 260 size_t survivor_size) { 261 262 assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check"); 263 264 // Stress testing. 265 if (PSAdaptiveSizePolicyResizeVirtualSpaceAlot == 0) { 266 request_young_gen_expansion(virtual_spaces()->alignment() * 3 / 2); 267 eden_size = young_gen()->eden_space()->capacity_in_bytes(); 268 } 269 270 // Expand only if the entire generation is already committed. 271 if (young_gen()->virtual_space()->uncommitted_size() == 0) { 272 size_t desired_size = eden_size + 2 * survivor_size; 273 const size_t committed = young_gen()->virtual_space()->committed_size(); 274 if (desired_size > committed) { 275 request_young_gen_expansion(desired_size - committed); 276 } 277 } 278 }