Tue, 14 Sep 2010 17:19:35 -0700
6984368: Large default heap size does not allow to use zero based compressed oops
Summary: take into account HeapBaseMinAddress and round down MaxPermSize
Reviewed-by: never
duke@435 | 1 | /* |
trims@1907 | 2 | * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
trims@1907 | 21 | * questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | # include "incls/_precompiled.incl" |
duke@435 | 26 | # include "incls/_collectorPolicy.cpp.incl" |
duke@435 | 27 | |
duke@435 | 28 | // CollectorPolicy methods. |
duke@435 | 29 | |
duke@435 | 30 | void CollectorPolicy::initialize_flags() { |
duke@435 | 31 | if (PermSize > MaxPermSize) { |
duke@435 | 32 | MaxPermSize = PermSize; |
duke@435 | 33 | } |
ysr@777 | 34 | PermSize = MAX2(min_alignment(), align_size_down_(PermSize, min_alignment())); |
kvn@2150 | 35 | // Don't increase Perm size limit above specified. |
kvn@2150 | 36 | MaxPermSize = align_size_down(MaxPermSize, max_alignment()); |
kvn@2150 | 37 | if (PermSize > MaxPermSize) { |
kvn@2150 | 38 | PermSize = MaxPermSize; |
kvn@2150 | 39 | } |
duke@435 | 40 | |
ysr@777 | 41 | MinPermHeapExpansion = MAX2(min_alignment(), align_size_down_(MinPermHeapExpansion, min_alignment())); |
ysr@777 | 42 | MaxPermHeapExpansion = MAX2(min_alignment(), align_size_down_(MaxPermHeapExpansion, min_alignment())); |
duke@435 | 43 | |
duke@435 | 44 | MinHeapDeltaBytes = align_size_up(MinHeapDeltaBytes, min_alignment()); |
duke@435 | 45 | |
duke@435 | 46 | SharedReadOnlySize = align_size_up(SharedReadOnlySize, max_alignment()); |
duke@435 | 47 | SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment()); |
duke@435 | 48 | SharedMiscDataSize = align_size_up(SharedMiscDataSize, max_alignment()); |
duke@435 | 49 | |
duke@435 | 50 | assert(PermSize % min_alignment() == 0, "permanent space alignment"); |
duke@435 | 51 | assert(MaxPermSize % max_alignment() == 0, "maximum permanent space alignment"); |
duke@435 | 52 | assert(SharedReadOnlySize % max_alignment() == 0, "read-only space alignment"); |
duke@435 | 53 | assert(SharedReadWriteSize % max_alignment() == 0, "read-write space alignment"); |
duke@435 | 54 | assert(SharedMiscDataSize % max_alignment() == 0, "misc-data space alignment"); |
duke@435 | 55 | if (PermSize < M) { |
duke@435 | 56 | vm_exit_during_initialization("Too small initial permanent heap"); |
duke@435 | 57 | } |
duke@435 | 58 | } |
duke@435 | 59 | |
duke@435 | 60 | void CollectorPolicy::initialize_size_info() { |
duke@435 | 61 | // User inputs from -mx and ms are aligned |
phh@1499 | 62 | set_initial_heap_byte_size(InitialHeapSize); |
jmasa@448 | 63 | if (initial_heap_byte_size() == 0) { |
jmasa@448 | 64 | set_initial_heap_byte_size(NewSize + OldSize); |
duke@435 | 65 | } |
ysr@777 | 66 | set_initial_heap_byte_size(align_size_up(_initial_heap_byte_size, |
ysr@777 | 67 | min_alignment())); |
ysr@777 | 68 | |
ysr@777 | 69 | set_min_heap_byte_size(Arguments::min_heap_size()); |
jmasa@448 | 70 | if (min_heap_byte_size() == 0) { |
jmasa@448 | 71 | set_min_heap_byte_size(NewSize + OldSize); |
duke@435 | 72 | } |
ysr@777 | 73 | set_min_heap_byte_size(align_size_up(_min_heap_byte_size, |
ysr@777 | 74 | min_alignment())); |
ysr@777 | 75 | |
ysr@777 | 76 | set_max_heap_byte_size(align_size_up(MaxHeapSize, max_alignment())); |
duke@435 | 77 | |
duke@435 | 78 | // Check heap parameter properties |
jmasa@448 | 79 | if (initial_heap_byte_size() < M) { |
duke@435 | 80 | vm_exit_during_initialization("Too small initial heap"); |
duke@435 | 81 | } |
duke@435 | 82 | // Check heap parameter properties |
jmasa@448 | 83 | if (min_heap_byte_size() < M) { |
duke@435 | 84 | vm_exit_during_initialization("Too small minimum heap"); |
duke@435 | 85 | } |
jmasa@448 | 86 | if (initial_heap_byte_size() <= NewSize) { |
duke@435 | 87 | // make sure there is at least some room in old space |
duke@435 | 88 | vm_exit_during_initialization("Too small initial heap for new size specified"); |
duke@435 | 89 | } |
jmasa@448 | 90 | if (max_heap_byte_size() < min_heap_byte_size()) { |
duke@435 | 91 | vm_exit_during_initialization("Incompatible minimum and maximum heap sizes specified"); |
duke@435 | 92 | } |
jmasa@448 | 93 | if (initial_heap_byte_size() < min_heap_byte_size()) { |
duke@435 | 94 | vm_exit_during_initialization("Incompatible minimum and initial heap sizes specified"); |
duke@435 | 95 | } |
jmasa@448 | 96 | if (max_heap_byte_size() < initial_heap_byte_size()) { |
duke@435 | 97 | vm_exit_during_initialization("Incompatible initial and maximum heap sizes specified"); |
duke@435 | 98 | } |
jmasa@448 | 99 | |
jmasa@448 | 100 | if (PrintGCDetails && Verbose) { |
jmasa@448 | 101 | gclog_or_tty->print_cr("Minimum heap " SIZE_FORMAT " Initial heap " |
jmasa@448 | 102 | SIZE_FORMAT " Maximum heap " SIZE_FORMAT, |
jmasa@448 | 103 | min_heap_byte_size(), initial_heap_byte_size(), max_heap_byte_size()); |
jmasa@448 | 104 | } |
duke@435 | 105 | } |
duke@435 | 106 | |
duke@435 | 107 | void CollectorPolicy::initialize_perm_generation(PermGen::Name pgnm) { |
duke@435 | 108 | _permanent_generation = |
duke@435 | 109 | new PermanentGenerationSpec(pgnm, PermSize, MaxPermSize, |
duke@435 | 110 | SharedReadOnlySize, |
duke@435 | 111 | SharedReadWriteSize, |
duke@435 | 112 | SharedMiscDataSize, |
duke@435 | 113 | SharedMiscCodeSize); |
duke@435 | 114 | if (_permanent_generation == NULL) { |
duke@435 | 115 | vm_exit_during_initialization("Unable to allocate gen spec"); |
duke@435 | 116 | } |
duke@435 | 117 | } |
duke@435 | 118 | |
jmasa@1822 | 119 | bool CollectorPolicy::use_should_clear_all_soft_refs(bool v) { |
jmasa@1822 | 120 | bool result = _should_clear_all_soft_refs; |
jmasa@1822 | 121 | set_should_clear_all_soft_refs(false); |
jmasa@1822 | 122 | return result; |
jmasa@1822 | 123 | } |
duke@435 | 124 | |
duke@435 | 125 | GenRemSet* CollectorPolicy::create_rem_set(MemRegion whole_heap, |
duke@435 | 126 | int max_covered_regions) { |
duke@435 | 127 | switch (rem_set_name()) { |
duke@435 | 128 | case GenRemSet::CardTable: { |
duke@435 | 129 | CardTableRS* res = new CardTableRS(whole_heap, max_covered_regions); |
duke@435 | 130 | return res; |
duke@435 | 131 | } |
duke@435 | 132 | default: |
duke@435 | 133 | guarantee(false, "unrecognized GenRemSet::Name"); |
duke@435 | 134 | return NULL; |
duke@435 | 135 | } |
duke@435 | 136 | } |
duke@435 | 137 | |
jmasa@1822 | 138 | void CollectorPolicy::cleared_all_soft_refs() { |
jmasa@1822 | 139 | // If near gc overhear limit, continue to clear SoftRefs. SoftRefs may |
jmasa@1822 | 140 | // have been cleared in the last collection but if the gc overhear |
jmasa@1822 | 141 | // limit continues to be near, SoftRefs should still be cleared. |
jmasa@1822 | 142 | if (size_policy() != NULL) { |
jmasa@1822 | 143 | _should_clear_all_soft_refs = size_policy()->gc_overhead_limit_near(); |
jmasa@1822 | 144 | } |
jmasa@1822 | 145 | _all_soft_refs_clear = true; |
jmasa@1822 | 146 | } |
jmasa@1822 | 147 | |
jmasa@1822 | 148 | |
duke@435 | 149 | // GenCollectorPolicy methods. |
duke@435 | 150 | |
jmasa@448 | 151 | size_t GenCollectorPolicy::scale_by_NewRatio_aligned(size_t base_size) { |
jmasa@448 | 152 | size_t x = base_size / (NewRatio+1); |
jmasa@448 | 153 | size_t new_gen_size = x > min_alignment() ? |
jmasa@448 | 154 | align_size_down(x, min_alignment()) : |
jmasa@448 | 155 | min_alignment(); |
jmasa@448 | 156 | return new_gen_size; |
jmasa@448 | 157 | } |
jmasa@448 | 158 | |
jmasa@448 | 159 | size_t GenCollectorPolicy::bound_minus_alignment(size_t desired_size, |
jmasa@448 | 160 | size_t maximum_size) { |
jmasa@448 | 161 | size_t alignment = min_alignment(); |
jmasa@448 | 162 | size_t max_minus = maximum_size - alignment; |
jmasa@448 | 163 | return desired_size < max_minus ? desired_size : max_minus; |
jmasa@448 | 164 | } |
jmasa@448 | 165 | |
jmasa@448 | 166 | |
duke@435 | 167 | void GenCollectorPolicy::initialize_size_policy(size_t init_eden_size, |
duke@435 | 168 | size_t init_promo_size, |
duke@435 | 169 | size_t init_survivor_size) { |
jmasa@448 | 170 | const double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0; |
duke@435 | 171 | _size_policy = new AdaptiveSizePolicy(init_eden_size, |
duke@435 | 172 | init_promo_size, |
duke@435 | 173 | init_survivor_size, |
duke@435 | 174 | max_gc_minor_pause_sec, |
duke@435 | 175 | GCTimeRatio); |
duke@435 | 176 | } |
duke@435 | 177 | |
duke@435 | 178 | size_t GenCollectorPolicy::compute_max_alignment() { |
duke@435 | 179 | // The card marking array and the offset arrays for old generations are |
duke@435 | 180 | // committed in os pages as well. Make sure they are entirely full (to |
duke@435 | 181 | // avoid partial page problems), e.g. if 512 bytes heap corresponds to 1 |
duke@435 | 182 | // byte entry and the os page size is 4096, the maximum heap size should |
duke@435 | 183 | // be 512*4096 = 2MB aligned. |
duke@435 | 184 | size_t alignment = GenRemSet::max_alignment_constraint(rem_set_name()); |
duke@435 | 185 | |
duke@435 | 186 | // Parallel GC does its own alignment of the generations to avoid requiring a |
duke@435 | 187 | // large page (256M on some platforms) for the permanent generation. The |
duke@435 | 188 | // other collectors should also be updated to do their own alignment and then |
duke@435 | 189 | // this use of lcm() should be removed. |
duke@435 | 190 | if (UseLargePages && !UseParallelGC) { |
duke@435 | 191 | // in presence of large pages we have to make sure that our |
duke@435 | 192 | // alignment is large page aware |
duke@435 | 193 | alignment = lcm(os::large_page_size(), alignment); |
duke@435 | 194 | } |
duke@435 | 195 | |
duke@435 | 196 | return alignment; |
duke@435 | 197 | } |
duke@435 | 198 | |
duke@435 | 199 | void GenCollectorPolicy::initialize_flags() { |
duke@435 | 200 | // All sizes must be multiples of the generation granularity. |
duke@435 | 201 | set_min_alignment((uintx) Generation::GenGrain); |
duke@435 | 202 | set_max_alignment(compute_max_alignment()); |
duke@435 | 203 | assert(max_alignment() >= min_alignment() && |
duke@435 | 204 | max_alignment() % min_alignment() == 0, |
duke@435 | 205 | "invalid alignment constraints"); |
duke@435 | 206 | |
duke@435 | 207 | CollectorPolicy::initialize_flags(); |
duke@435 | 208 | |
duke@435 | 209 | // All generational heaps have a youngest gen; handle those flags here. |
duke@435 | 210 | |
duke@435 | 211 | // Adjust max size parameters |
duke@435 | 212 | if (NewSize > MaxNewSize) { |
duke@435 | 213 | MaxNewSize = NewSize; |
duke@435 | 214 | } |
duke@435 | 215 | NewSize = align_size_down(NewSize, min_alignment()); |
duke@435 | 216 | MaxNewSize = align_size_down(MaxNewSize, min_alignment()); |
duke@435 | 217 | |
duke@435 | 218 | // Check validity of heap flags |
duke@435 | 219 | assert(NewSize % min_alignment() == 0, "eden space alignment"); |
duke@435 | 220 | assert(MaxNewSize % min_alignment() == 0, "survivor space alignment"); |
duke@435 | 221 | |
duke@435 | 222 | if (NewSize < 3*min_alignment()) { |
duke@435 | 223 | // make sure there room for eden and two survivor spaces |
duke@435 | 224 | vm_exit_during_initialization("Too small new size specified"); |
duke@435 | 225 | } |
duke@435 | 226 | if (SurvivorRatio < 1 || NewRatio < 1) { |
duke@435 | 227 | vm_exit_during_initialization("Invalid heap ratio specified"); |
duke@435 | 228 | } |
duke@435 | 229 | } |
duke@435 | 230 | |
duke@435 | 231 | void TwoGenerationCollectorPolicy::initialize_flags() { |
duke@435 | 232 | GenCollectorPolicy::initialize_flags(); |
duke@435 | 233 | |
duke@435 | 234 | OldSize = align_size_down(OldSize, min_alignment()); |
duke@435 | 235 | if (NewSize + OldSize > MaxHeapSize) { |
duke@435 | 236 | MaxHeapSize = NewSize + OldSize; |
duke@435 | 237 | } |
duke@435 | 238 | MaxHeapSize = align_size_up(MaxHeapSize, max_alignment()); |
duke@435 | 239 | |
duke@435 | 240 | always_do_update_barrier = UseConcMarkSweepGC; |
duke@435 | 241 | BlockOffsetArrayUseUnallocatedBlock = |
duke@435 | 242 | BlockOffsetArrayUseUnallocatedBlock || ParallelGCThreads > 0; |
duke@435 | 243 | |
duke@435 | 244 | // Check validity of heap flags |
duke@435 | 245 | assert(OldSize % min_alignment() == 0, "old space alignment"); |
duke@435 | 246 | assert(MaxHeapSize % max_alignment() == 0, "maximum heap alignment"); |
duke@435 | 247 | } |
duke@435 | 248 | |
jmasa@448 | 249 | // Values set on the command line win over any ergonomically |
jmasa@448 | 250 | // set command line parameters. |
jmasa@448 | 251 | // Ergonomic choice of parameters are done before this |
jmasa@448 | 252 | // method is called. Values for command line parameters such as NewSize |
jmasa@448 | 253 | // and MaxNewSize feed those ergonomic choices into this method. |
jmasa@448 | 254 | // This method makes the final generation sizings consistent with |
jmasa@448 | 255 | // themselves and with overall heap sizings. |
jmasa@448 | 256 | // In the absence of explicitly set command line flags, policies |
jmasa@448 | 257 | // such as the use of NewRatio are used to size the generation. |
duke@435 | 258 | void GenCollectorPolicy::initialize_size_info() { |
duke@435 | 259 | CollectorPolicy::initialize_size_info(); |
duke@435 | 260 | |
jmasa@448 | 261 | // min_alignment() is used for alignment within a generation. |
jmasa@448 | 262 | // There is additional alignment done down stream for some |
jmasa@448 | 263 | // collectors that sometimes causes unwanted rounding up of |
jmasa@448 | 264 | // generations sizes. |
jmasa@448 | 265 | |
jmasa@448 | 266 | // Determine maximum size of gen0 |
jmasa@448 | 267 | |
jmasa@448 | 268 | size_t max_new_size = 0; |
jmasa@448 | 269 | if (FLAG_IS_CMDLINE(MaxNewSize)) { |
jmasa@448 | 270 | if (MaxNewSize < min_alignment()) { |
jmasa@448 | 271 | max_new_size = min_alignment(); |
jmasa@448 | 272 | } else if (MaxNewSize >= max_heap_byte_size()) { |
jmasa@448 | 273 | max_new_size = align_size_down(max_heap_byte_size() - min_alignment(), |
jmasa@448 | 274 | min_alignment()); |
jmasa@448 | 275 | warning("MaxNewSize (" SIZE_FORMAT "k) is equal to or " |
jmasa@448 | 276 | "greater than the entire heap (" SIZE_FORMAT "k). A " |
jmasa@448 | 277 | "new generation size of " SIZE_FORMAT "k will be used.", |
jmasa@448 | 278 | MaxNewSize/K, max_heap_byte_size()/K, max_new_size/K); |
jmasa@448 | 279 | } else { |
jmasa@448 | 280 | max_new_size = align_size_down(MaxNewSize, min_alignment()); |
jmasa@448 | 281 | } |
jmasa@448 | 282 | |
jmasa@448 | 283 | // The case for FLAG_IS_ERGO(MaxNewSize) could be treated |
jmasa@448 | 284 | // specially at this point to just use an ergonomically set |
jmasa@448 | 285 | // MaxNewSize to set max_new_size. For cases with small |
jmasa@448 | 286 | // heaps such a policy often did not work because the MaxNewSize |
jmasa@448 | 287 | // was larger than the entire heap. The interpretation given |
jmasa@448 | 288 | // to ergonomically set flags is that the flags are set |
jmasa@448 | 289 | // by different collectors for their own special needs but |
jmasa@448 | 290 | // are not allowed to badly shape the heap. This allows the |
jmasa@448 | 291 | // different collectors to decide what's best for themselves |
jmasa@448 | 292 | // without having to factor in the overall heap shape. It |
jmasa@448 | 293 | // can be the case in the future that the collectors would |
jmasa@448 | 294 | // only make "wise" ergonomics choices and this policy could |
jmasa@448 | 295 | // just accept those choices. The choices currently made are |
jmasa@448 | 296 | // not always "wise". |
duke@435 | 297 | } else { |
jmasa@448 | 298 | max_new_size = scale_by_NewRatio_aligned(max_heap_byte_size()); |
jmasa@448 | 299 | // Bound the maximum size by NewSize below (since it historically |
duke@435 | 300 | // would have been NewSize and because the NewRatio calculation could |
duke@435 | 301 | // yield a size that is too small) and bound it by MaxNewSize above. |
jmasa@448 | 302 | // Ergonomics plays here by previously calculating the desired |
jmasa@448 | 303 | // NewSize and MaxNewSize. |
jmasa@448 | 304 | max_new_size = MIN2(MAX2(max_new_size, NewSize), MaxNewSize); |
jmasa@448 | 305 | } |
jmasa@448 | 306 | assert(max_new_size > 0, "All paths should set max_new_size"); |
jmasa@448 | 307 | |
jmasa@448 | 308 | // Given the maximum gen0 size, determine the initial and |
jmasa@448 | 309 | // minimum sizes. |
jmasa@448 | 310 | |
jmasa@448 | 311 | if (max_heap_byte_size() == min_heap_byte_size()) { |
jmasa@448 | 312 | // The maximum and minimum heap sizes are the same so |
jmasa@448 | 313 | // the generations minimum and initial must be the |
jmasa@448 | 314 | // same as its maximum. |
jmasa@448 | 315 | set_min_gen0_size(max_new_size); |
jmasa@448 | 316 | set_initial_gen0_size(max_new_size); |
jmasa@448 | 317 | set_max_gen0_size(max_new_size); |
jmasa@448 | 318 | } else { |
jmasa@448 | 319 | size_t desired_new_size = 0; |
jmasa@448 | 320 | if (!FLAG_IS_DEFAULT(NewSize)) { |
jmasa@448 | 321 | // If NewSize is set ergonomically (for example by cms), it |
jmasa@448 | 322 | // would make sense to use it. If it is used, also use it |
jmasa@448 | 323 | // to set the initial size. Although there is no reason |
jmasa@448 | 324 | // the minimum size and the initial size have to be the same, |
jmasa@448 | 325 | // the current implementation gets into trouble during the calculation |
jmasa@448 | 326 | // of the tenured generation sizes if they are different. |
jmasa@448 | 327 | // Note that this makes the initial size and the minimum size |
jmasa@448 | 328 | // generally small compared to the NewRatio calculation. |
jmasa@448 | 329 | _min_gen0_size = NewSize; |
jmasa@448 | 330 | desired_new_size = NewSize; |
jmasa@448 | 331 | max_new_size = MAX2(max_new_size, NewSize); |
jmasa@448 | 332 | } else { |
jmasa@448 | 333 | // For the case where NewSize is the default, use NewRatio |
jmasa@448 | 334 | // to size the minimum and initial generation sizes. |
jmasa@448 | 335 | // Use the default NewSize as the floor for these values. If |
jmasa@448 | 336 | // NewRatio is overly large, the resulting sizes can be too |
jmasa@448 | 337 | // small. |
jmasa@448 | 338 | _min_gen0_size = MAX2(scale_by_NewRatio_aligned(min_heap_byte_size()), |
jmasa@448 | 339 | NewSize); |
jmasa@448 | 340 | desired_new_size = |
jmasa@448 | 341 | MAX2(scale_by_NewRatio_aligned(initial_heap_byte_size()), |
jmasa@448 | 342 | NewSize); |
jmasa@448 | 343 | } |
jmasa@448 | 344 | |
jmasa@448 | 345 | assert(_min_gen0_size > 0, "Sanity check"); |
jmasa@448 | 346 | set_initial_gen0_size(desired_new_size); |
jmasa@448 | 347 | set_max_gen0_size(max_new_size); |
jmasa@448 | 348 | |
jmasa@448 | 349 | // At this point the desirable initial and minimum sizes have been |
jmasa@448 | 350 | // determined without regard to the maximum sizes. |
jmasa@448 | 351 | |
jmasa@448 | 352 | // Bound the sizes by the corresponding overall heap sizes. |
jmasa@448 | 353 | set_min_gen0_size( |
jmasa@448 | 354 | bound_minus_alignment(_min_gen0_size, min_heap_byte_size())); |
jmasa@448 | 355 | set_initial_gen0_size( |
jmasa@448 | 356 | bound_minus_alignment(_initial_gen0_size, initial_heap_byte_size())); |
jmasa@448 | 357 | set_max_gen0_size( |
jmasa@448 | 358 | bound_minus_alignment(_max_gen0_size, max_heap_byte_size())); |
jmasa@448 | 359 | |
jmasa@448 | 360 | // At this point all three sizes have been checked against the |
jmasa@448 | 361 | // maximum sizes but have not been checked for consistency |
ysr@777 | 362 | // among the three. |
jmasa@448 | 363 | |
jmasa@448 | 364 | // Final check min <= initial <= max |
jmasa@448 | 365 | set_min_gen0_size(MIN2(_min_gen0_size, _max_gen0_size)); |
jmasa@448 | 366 | set_initial_gen0_size( |
jmasa@448 | 367 | MAX2(MIN2(_initial_gen0_size, _max_gen0_size), _min_gen0_size)); |
jmasa@448 | 368 | set_min_gen0_size(MIN2(_min_gen0_size, _initial_gen0_size)); |
duke@435 | 369 | } |
duke@435 | 370 | |
jmasa@448 | 371 | if (PrintGCDetails && Verbose) { |
jmasa@448 | 372 | gclog_or_tty->print_cr("Minimum gen0 " SIZE_FORMAT " Initial gen0 " |
jmasa@448 | 373 | SIZE_FORMAT " Maximum gen0 " SIZE_FORMAT, |
jmasa@448 | 374 | min_gen0_size(), initial_gen0_size(), max_gen0_size()); |
jmasa@448 | 375 | } |
jmasa@448 | 376 | } |
duke@435 | 377 | |
jmasa@448 | 378 | // Call this method during the sizing of the gen1 to make |
jmasa@448 | 379 | // adjustments to gen0 because of gen1 sizing policy. gen0 initially has |
jmasa@448 | 380 | // the most freedom in sizing because it is done before the |
jmasa@448 | 381 | // policy for gen1 is applied. Once gen1 policies have been applied, |
jmasa@448 | 382 | // there may be conflicts in the shape of the heap and this method |
jmasa@448 | 383 | // is used to make the needed adjustments. The application of the |
jmasa@448 | 384 | // policies could be more sophisticated (iterative for example) but |
jmasa@448 | 385 | // keeping it simple also seems a worthwhile goal. |
jmasa@448 | 386 | bool TwoGenerationCollectorPolicy::adjust_gen0_sizes(size_t* gen0_size_ptr, |
jmasa@448 | 387 | size_t* gen1_size_ptr, |
jmasa@448 | 388 | size_t heap_size, |
jmasa@448 | 389 | size_t min_gen0_size) { |
jmasa@448 | 390 | bool result = false; |
jmasa@448 | 391 | if ((*gen1_size_ptr + *gen0_size_ptr) > heap_size) { |
jmasa@448 | 392 | if (((*gen0_size_ptr + OldSize) > heap_size) && |
jmasa@448 | 393 | (heap_size - min_gen0_size) >= min_alignment()) { |
jmasa@448 | 394 | // Adjust gen0 down to accomodate OldSize |
jmasa@448 | 395 | *gen0_size_ptr = heap_size - min_gen0_size; |
jmasa@448 | 396 | *gen0_size_ptr = |
jmasa@448 | 397 | MAX2((uintx)align_size_down(*gen0_size_ptr, min_alignment()), |
jmasa@448 | 398 | min_alignment()); |
jmasa@448 | 399 | assert(*gen0_size_ptr > 0, "Min gen0 is too large"); |
jmasa@448 | 400 | result = true; |
jmasa@448 | 401 | } else { |
jmasa@448 | 402 | *gen1_size_ptr = heap_size - *gen0_size_ptr; |
jmasa@448 | 403 | *gen1_size_ptr = |
jmasa@448 | 404 | MAX2((uintx)align_size_down(*gen1_size_ptr, min_alignment()), |
jmasa@448 | 405 | min_alignment()); |
jmasa@448 | 406 | } |
jmasa@448 | 407 | } |
jmasa@448 | 408 | return result; |
jmasa@448 | 409 | } |
duke@435 | 410 | |
jmasa@448 | 411 | // Minimum sizes of the generations may be different than |
jmasa@448 | 412 | // the initial sizes. An inconsistently is permitted here |
jmasa@448 | 413 | // in the total size that can be specified explicitly by |
jmasa@448 | 414 | // command line specification of OldSize and NewSize and |
jmasa@448 | 415 | // also a command line specification of -Xms. Issue a warning |
jmasa@448 | 416 | // but allow the values to pass. |
duke@435 | 417 | |
duke@435 | 418 | void TwoGenerationCollectorPolicy::initialize_size_info() { |
duke@435 | 419 | GenCollectorPolicy::initialize_size_info(); |
duke@435 | 420 | |
jmasa@448 | 421 | // At this point the minimum, initial and maximum sizes |
jmasa@448 | 422 | // of the overall heap and of gen0 have been determined. |
jmasa@448 | 423 | // The maximum gen1 size can be determined from the maximum gen0 |
jmasa@448 | 424 | // and maximum heap size since not explicit flags exits |
jmasa@448 | 425 | // for setting the gen1 maximum. |
jmasa@448 | 426 | _max_gen1_size = max_heap_byte_size() - _max_gen0_size; |
jmasa@448 | 427 | _max_gen1_size = |
jmasa@448 | 428 | MAX2((uintx)align_size_down(_max_gen1_size, min_alignment()), |
jmasa@448 | 429 | min_alignment()); |
jmasa@448 | 430 | // If no explicit command line flag has been set for the |
jmasa@448 | 431 | // gen1 size, use what is left for gen1. |
jmasa@448 | 432 | if (FLAG_IS_DEFAULT(OldSize) || FLAG_IS_ERGO(OldSize)) { |
jmasa@448 | 433 | // The user has not specified any value or ergonomics |
jmasa@448 | 434 | // has chosen a value (which may or may not be consistent |
jmasa@448 | 435 | // with the overall heap size). In either case make |
jmasa@448 | 436 | // the minimum, maximum and initial sizes consistent |
jmasa@448 | 437 | // with the gen0 sizes and the overall heap sizes. |
jmasa@448 | 438 | assert(min_heap_byte_size() > _min_gen0_size, |
jmasa@448 | 439 | "gen0 has an unexpected minimum size"); |
jmasa@448 | 440 | set_min_gen1_size(min_heap_byte_size() - min_gen0_size()); |
jmasa@448 | 441 | set_min_gen1_size( |
jmasa@448 | 442 | MAX2((uintx)align_size_down(_min_gen1_size, min_alignment()), |
jmasa@448 | 443 | min_alignment())); |
jmasa@448 | 444 | set_initial_gen1_size(initial_heap_byte_size() - initial_gen0_size()); |
jmasa@448 | 445 | set_initial_gen1_size( |
jmasa@448 | 446 | MAX2((uintx)align_size_down(_initial_gen1_size, min_alignment()), |
jmasa@448 | 447 | min_alignment())); |
jmasa@448 | 448 | |
jmasa@448 | 449 | } else { |
jmasa@448 | 450 | // It's been explicitly set on the command line. Use the |
jmasa@448 | 451 | // OldSize and then determine the consequences. |
jmasa@448 | 452 | set_min_gen1_size(OldSize); |
jmasa@448 | 453 | set_initial_gen1_size(OldSize); |
jmasa@448 | 454 | |
jmasa@448 | 455 | // If the user has explicitly set an OldSize that is inconsistent |
jmasa@448 | 456 | // with other command line flags, issue a warning. |
duke@435 | 457 | // The generation minimums and the overall heap mimimum should |
duke@435 | 458 | // be within one heap alignment. |
jmasa@448 | 459 | if ((_min_gen1_size + _min_gen0_size + min_alignment()) < |
jmasa@448 | 460 | min_heap_byte_size()) { |
duke@435 | 461 | warning("Inconsistency between minimum heap size and minimum " |
jmasa@448 | 462 | "generation sizes: using minimum heap = " SIZE_FORMAT, |
jmasa@448 | 463 | min_heap_byte_size()); |
duke@435 | 464 | } |
jmasa@448 | 465 | if ((OldSize > _max_gen1_size)) { |
jmasa@448 | 466 | warning("Inconsistency between maximum heap size and maximum " |
jmasa@448 | 467 | "generation sizes: using maximum heap = " SIZE_FORMAT |
jmasa@448 | 468 | " -XX:OldSize flag is being ignored", |
jmasa@448 | 469 | max_heap_byte_size()); |
duke@435 | 470 | } |
jmasa@448 | 471 | // If there is an inconsistency between the OldSize and the minimum and/or |
jmasa@448 | 472 | // initial size of gen0, since OldSize was explicitly set, OldSize wins. |
jmasa@448 | 473 | if (adjust_gen0_sizes(&_min_gen0_size, &_min_gen1_size, |
jmasa@448 | 474 | min_heap_byte_size(), OldSize)) { |
jmasa@448 | 475 | if (PrintGCDetails && Verbose) { |
jmasa@448 | 476 | gclog_or_tty->print_cr("Minimum gen0 " SIZE_FORMAT " Initial gen0 " |
jmasa@448 | 477 | SIZE_FORMAT " Maximum gen0 " SIZE_FORMAT, |
jmasa@448 | 478 | min_gen0_size(), initial_gen0_size(), max_gen0_size()); |
jmasa@448 | 479 | } |
jmasa@448 | 480 | } |
jmasa@448 | 481 | // Initial size |
jmasa@448 | 482 | if (adjust_gen0_sizes(&_initial_gen0_size, &_initial_gen1_size, |
jmasa@448 | 483 | initial_heap_byte_size(), OldSize)) { |
jmasa@448 | 484 | if (PrintGCDetails && Verbose) { |
jmasa@448 | 485 | gclog_or_tty->print_cr("Minimum gen0 " SIZE_FORMAT " Initial gen0 " |
jmasa@448 | 486 | SIZE_FORMAT " Maximum gen0 " SIZE_FORMAT, |
jmasa@448 | 487 | min_gen0_size(), initial_gen0_size(), max_gen0_size()); |
jmasa@448 | 488 | } |
jmasa@448 | 489 | } |
jmasa@448 | 490 | } |
jmasa@448 | 491 | // Enforce the maximum gen1 size. |
jmasa@448 | 492 | set_min_gen1_size(MIN2(_min_gen1_size, _max_gen1_size)); |
duke@435 | 493 | |
jmasa@448 | 494 | // Check that min gen1 <= initial gen1 <= max gen1 |
jmasa@448 | 495 | set_initial_gen1_size(MAX2(_initial_gen1_size, _min_gen1_size)); |
jmasa@448 | 496 | set_initial_gen1_size(MIN2(_initial_gen1_size, _max_gen1_size)); |
jmasa@448 | 497 | |
jmasa@448 | 498 | if (PrintGCDetails && Verbose) { |
jmasa@448 | 499 | gclog_or_tty->print_cr("Minimum gen1 " SIZE_FORMAT " Initial gen1 " |
jmasa@448 | 500 | SIZE_FORMAT " Maximum gen1 " SIZE_FORMAT, |
jmasa@448 | 501 | min_gen1_size(), initial_gen1_size(), max_gen1_size()); |
jmasa@448 | 502 | } |
duke@435 | 503 | } |
duke@435 | 504 | |
duke@435 | 505 | HeapWord* GenCollectorPolicy::mem_allocate_work(size_t size, |
duke@435 | 506 | bool is_tlab, |
duke@435 | 507 | bool* gc_overhead_limit_was_exceeded) { |
duke@435 | 508 | GenCollectedHeap *gch = GenCollectedHeap::heap(); |
duke@435 | 509 | |
duke@435 | 510 | debug_only(gch->check_for_valid_allocation_state()); |
duke@435 | 511 | assert(gch->no_gc_in_progress(), "Allocation during gc not allowed"); |
jmasa@1822 | 512 | |
jmasa@1822 | 513 | // In general gc_overhead_limit_was_exceeded should be false so |
jmasa@1822 | 514 | // set it so here and reset it to true only if the gc time |
jmasa@1822 | 515 | // limit is being exceeded as checked below. |
jmasa@1822 | 516 | *gc_overhead_limit_was_exceeded = false; |
jmasa@1822 | 517 | |
duke@435 | 518 | HeapWord* result = NULL; |
duke@435 | 519 | |
duke@435 | 520 | // Loop until the allocation is satisified, |
duke@435 | 521 | // or unsatisfied after GC. |
duke@435 | 522 | for (int try_count = 1; /* return or throw */; try_count += 1) { |
duke@435 | 523 | HandleMark hm; // discard any handles allocated in each iteration |
duke@435 | 524 | |
duke@435 | 525 | // First allocation attempt is lock-free. |
duke@435 | 526 | Generation *gen0 = gch->get_gen(0); |
duke@435 | 527 | assert(gen0->supports_inline_contig_alloc(), |
duke@435 | 528 | "Otherwise, must do alloc within heap lock"); |
duke@435 | 529 | if (gen0->should_allocate(size, is_tlab)) { |
duke@435 | 530 | result = gen0->par_allocate(size, is_tlab); |
duke@435 | 531 | if (result != NULL) { |
duke@435 | 532 | assert(gch->is_in_reserved(result), "result not in heap"); |
duke@435 | 533 | return result; |
duke@435 | 534 | } |
duke@435 | 535 | } |
duke@435 | 536 | unsigned int gc_count_before; // read inside the Heap_lock locked region |
duke@435 | 537 | { |
duke@435 | 538 | MutexLocker ml(Heap_lock); |
duke@435 | 539 | if (PrintGC && Verbose) { |
duke@435 | 540 | gclog_or_tty->print_cr("TwoGenerationCollectorPolicy::mem_allocate_work:" |
duke@435 | 541 | " attempting locked slow path allocation"); |
duke@435 | 542 | } |
duke@435 | 543 | // Note that only large objects get a shot at being |
duke@435 | 544 | // allocated in later generations. |
duke@435 | 545 | bool first_only = ! should_try_older_generation_allocation(size); |
duke@435 | 546 | |
duke@435 | 547 | result = gch->attempt_allocation(size, is_tlab, first_only); |
duke@435 | 548 | if (result != NULL) { |
duke@435 | 549 | assert(gch->is_in_reserved(result), "result not in heap"); |
duke@435 | 550 | return result; |
duke@435 | 551 | } |
duke@435 | 552 | |
duke@435 | 553 | if (GC_locker::is_active_and_needs_gc()) { |
duke@435 | 554 | if (is_tlab) { |
duke@435 | 555 | return NULL; // Caller will retry allocating individual object |
duke@435 | 556 | } |
duke@435 | 557 | if (!gch->is_maximal_no_gc()) { |
duke@435 | 558 | // Try and expand heap to satisfy request |
duke@435 | 559 | result = expand_heap_and_allocate(size, is_tlab); |
duke@435 | 560 | // result could be null if we are out of space |
duke@435 | 561 | if (result != NULL) { |
duke@435 | 562 | return result; |
duke@435 | 563 | } |
duke@435 | 564 | } |
duke@435 | 565 | |
duke@435 | 566 | // If this thread is not in a jni critical section, we stall |
duke@435 | 567 | // the requestor until the critical section has cleared and |
duke@435 | 568 | // GC allowed. When the critical section clears, a GC is |
duke@435 | 569 | // initiated by the last thread exiting the critical section; so |
duke@435 | 570 | // we retry the allocation sequence from the beginning of the loop, |
duke@435 | 571 | // rather than causing more, now probably unnecessary, GC attempts. |
duke@435 | 572 | JavaThread* jthr = JavaThread::current(); |
duke@435 | 573 | if (!jthr->in_critical()) { |
duke@435 | 574 | MutexUnlocker mul(Heap_lock); |
duke@435 | 575 | // Wait for JNI critical section to be exited |
duke@435 | 576 | GC_locker::stall_until_clear(); |
duke@435 | 577 | continue; |
duke@435 | 578 | } else { |
duke@435 | 579 | if (CheckJNICalls) { |
duke@435 | 580 | fatal("Possible deadlock due to allocating while" |
duke@435 | 581 | " in jni critical section"); |
duke@435 | 582 | } |
duke@435 | 583 | return NULL; |
duke@435 | 584 | } |
duke@435 | 585 | } |
duke@435 | 586 | |
duke@435 | 587 | // Read the gc count while the heap lock is held. |
duke@435 | 588 | gc_count_before = Universe::heap()->total_collections(); |
duke@435 | 589 | } |
duke@435 | 590 | |
duke@435 | 591 | VM_GenCollectForAllocation op(size, |
duke@435 | 592 | is_tlab, |
duke@435 | 593 | gc_count_before); |
duke@435 | 594 | VMThread::execute(&op); |
duke@435 | 595 | if (op.prologue_succeeded()) { |
duke@435 | 596 | result = op.result(); |
duke@435 | 597 | if (op.gc_locked()) { |
duke@435 | 598 | assert(result == NULL, "must be NULL if gc_locked() is true"); |
duke@435 | 599 | continue; // retry and/or stall as necessary |
duke@435 | 600 | } |
jmasa@1822 | 601 | |
jmasa@1822 | 602 | // Allocation has failed and a collection |
jmasa@1822 | 603 | // has been done. If the gc time limit was exceeded the |
jmasa@1822 | 604 | // this time, return NULL so that an out-of-memory |
jmasa@1822 | 605 | // will be thrown. Clear gc_overhead_limit_exceeded |
jmasa@1822 | 606 | // so that the overhead exceeded does not persist. |
jmasa@1822 | 607 | |
jmasa@1822 | 608 | const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded(); |
jmasa@1822 | 609 | const bool softrefs_clear = all_soft_refs_clear(); |
jmasa@1822 | 610 | assert(!limit_exceeded || softrefs_clear, "Should have been cleared"); |
jmasa@1822 | 611 | if (limit_exceeded && softrefs_clear) { |
jmasa@1822 | 612 | *gc_overhead_limit_was_exceeded = true; |
jmasa@1822 | 613 | size_policy()->set_gc_overhead_limit_exceeded(false); |
jmasa@1822 | 614 | if (op.result() != NULL) { |
jmasa@1822 | 615 | CollectedHeap::fill_with_object(op.result(), size); |
jmasa@1822 | 616 | } |
jmasa@1822 | 617 | return NULL; |
jmasa@1822 | 618 | } |
duke@435 | 619 | assert(result == NULL || gch->is_in_reserved(result), |
duke@435 | 620 | "result not in heap"); |
duke@435 | 621 | return result; |
duke@435 | 622 | } |
duke@435 | 623 | |
duke@435 | 624 | // Give a warning if we seem to be looping forever. |
duke@435 | 625 | if ((QueuedAllocationWarningCount > 0) && |
duke@435 | 626 | (try_count % QueuedAllocationWarningCount == 0)) { |
duke@435 | 627 | warning("TwoGenerationCollectorPolicy::mem_allocate_work retries %d times \n\t" |
duke@435 | 628 | " size=%d %s", try_count, size, is_tlab ? "(TLAB)" : ""); |
duke@435 | 629 | } |
duke@435 | 630 | } |
duke@435 | 631 | } |
duke@435 | 632 | |
duke@435 | 633 | HeapWord* GenCollectorPolicy::expand_heap_and_allocate(size_t size, |
duke@435 | 634 | bool is_tlab) { |
duke@435 | 635 | GenCollectedHeap *gch = GenCollectedHeap::heap(); |
duke@435 | 636 | HeapWord* result = NULL; |
duke@435 | 637 | for (int i = number_of_generations() - 1; i >= 0 && result == NULL; i--) { |
duke@435 | 638 | Generation *gen = gch->get_gen(i); |
duke@435 | 639 | if (gen->should_allocate(size, is_tlab)) { |
duke@435 | 640 | result = gen->expand_and_allocate(size, is_tlab); |
duke@435 | 641 | } |
duke@435 | 642 | } |
duke@435 | 643 | assert(result == NULL || gch->is_in_reserved(result), "result not in heap"); |
duke@435 | 644 | return result; |
duke@435 | 645 | } |
duke@435 | 646 | |
duke@435 | 647 | HeapWord* GenCollectorPolicy::satisfy_failed_allocation(size_t size, |
duke@435 | 648 | bool is_tlab) { |
duke@435 | 649 | GenCollectedHeap *gch = GenCollectedHeap::heap(); |
duke@435 | 650 | GCCauseSetter x(gch, GCCause::_allocation_failure); |
duke@435 | 651 | HeapWord* result = NULL; |
duke@435 | 652 | |
duke@435 | 653 | assert(size != 0, "Precondition violated"); |
duke@435 | 654 | if (GC_locker::is_active_and_needs_gc()) { |
duke@435 | 655 | // GC locker is active; instead of a collection we will attempt |
duke@435 | 656 | // to expand the heap, if there's room for expansion. |
duke@435 | 657 | if (!gch->is_maximal_no_gc()) { |
duke@435 | 658 | result = expand_heap_and_allocate(size, is_tlab); |
duke@435 | 659 | } |
duke@435 | 660 | return result; // could be null if we are out of space |
duke@435 | 661 | } else if (!gch->incremental_collection_will_fail()) { |
duke@435 | 662 | // The gc_prologues have not executed yet. The value |
duke@435 | 663 | // for incremental_collection_will_fail() is the remanent |
duke@435 | 664 | // of the last collection. |
duke@435 | 665 | // Do an incremental collection. |
duke@435 | 666 | gch->do_collection(false /* full */, |
duke@435 | 667 | false /* clear_all_soft_refs */, |
duke@435 | 668 | size /* size */, |
duke@435 | 669 | is_tlab /* is_tlab */, |
duke@435 | 670 | number_of_generations() - 1 /* max_level */); |
duke@435 | 671 | } else { |
duke@435 | 672 | // Try a full collection; see delta for bug id 6266275 |
duke@435 | 673 | // for the original code and why this has been simplified |
duke@435 | 674 | // with from-space allocation criteria modified and |
duke@435 | 675 | // such allocation moved out of the safepoint path. |
duke@435 | 676 | gch->do_collection(true /* full */, |
duke@435 | 677 | false /* clear_all_soft_refs */, |
duke@435 | 678 | size /* size */, |
duke@435 | 679 | is_tlab /* is_tlab */, |
duke@435 | 680 | number_of_generations() - 1 /* max_level */); |
duke@435 | 681 | } |
duke@435 | 682 | |
duke@435 | 683 | result = gch->attempt_allocation(size, is_tlab, false /*first_only*/); |
duke@435 | 684 | |
duke@435 | 685 | if (result != NULL) { |
duke@435 | 686 | assert(gch->is_in_reserved(result), "result not in heap"); |
duke@435 | 687 | return result; |
duke@435 | 688 | } |
duke@435 | 689 | |
duke@435 | 690 | // OK, collection failed, try expansion. |
duke@435 | 691 | result = expand_heap_and_allocate(size, is_tlab); |
duke@435 | 692 | if (result != NULL) { |
duke@435 | 693 | return result; |
duke@435 | 694 | } |
duke@435 | 695 | |
duke@435 | 696 | // If we reach this point, we're really out of memory. Try every trick |
duke@435 | 697 | // we can to reclaim memory. Force collection of soft references. Force |
duke@435 | 698 | // a complete compaction of the heap. Any additional methods for finding |
duke@435 | 699 | // free memory should be here, especially if they are expensive. If this |
duke@435 | 700 | // attempt fails, an OOM exception will be thrown. |
duke@435 | 701 | { |
duke@435 | 702 | IntFlagSetting flag_change(MarkSweepAlwaysCompactCount, 1); // Make sure the heap is fully compacted |
duke@435 | 703 | |
duke@435 | 704 | gch->do_collection(true /* full */, |
duke@435 | 705 | true /* clear_all_soft_refs */, |
duke@435 | 706 | size /* size */, |
duke@435 | 707 | is_tlab /* is_tlab */, |
duke@435 | 708 | number_of_generations() - 1 /* max_level */); |
duke@435 | 709 | } |
duke@435 | 710 | |
duke@435 | 711 | result = gch->attempt_allocation(size, is_tlab, false /* first_only */); |
duke@435 | 712 | if (result != NULL) { |
duke@435 | 713 | assert(gch->is_in_reserved(result), "result not in heap"); |
duke@435 | 714 | return result; |
duke@435 | 715 | } |
duke@435 | 716 | |
jmasa@1822 | 717 | assert(!should_clear_all_soft_refs(), |
jmasa@1822 | 718 | "Flag should have been handled and cleared prior to this point"); |
jmasa@1822 | 719 | |
duke@435 | 720 | // What else? We might try synchronous finalization later. If the total |
duke@435 | 721 | // space available is large enough for the allocation, then a more |
duke@435 | 722 | // complete compaction phase than we've tried so far might be |
duke@435 | 723 | // appropriate. |
duke@435 | 724 | return NULL; |
duke@435 | 725 | } |
duke@435 | 726 | |
duke@435 | 727 | size_t GenCollectorPolicy::large_typearray_limit() { |
duke@435 | 728 | return FastAllocateSizeLimit; |
duke@435 | 729 | } |
duke@435 | 730 | |
duke@435 | 731 | // Return true if any of the following is true: |
duke@435 | 732 | // . the allocation won't fit into the current young gen heap |
duke@435 | 733 | // . gc locker is occupied (jni critical section) |
duke@435 | 734 | // . heap memory is tight -- the most recent previous collection |
duke@435 | 735 | // was a full collection because a partial collection (would |
duke@435 | 736 | // have) failed and is likely to fail again |
duke@435 | 737 | bool GenCollectorPolicy::should_try_older_generation_allocation( |
duke@435 | 738 | size_t word_size) const { |
duke@435 | 739 | GenCollectedHeap* gch = GenCollectedHeap::heap(); |
duke@435 | 740 | size_t gen0_capacity = gch->get_gen(0)->capacity_before_gc(); |
duke@435 | 741 | return (word_size > heap_word_size(gen0_capacity)) |
duke@435 | 742 | || (GC_locker::is_active_and_needs_gc()) |
duke@435 | 743 | || ( gch->last_incremental_collection_failed() |
duke@435 | 744 | && gch->incremental_collection_will_fail()); |
duke@435 | 745 | } |
duke@435 | 746 | |
duke@435 | 747 | |
duke@435 | 748 | // |
duke@435 | 749 | // MarkSweepPolicy methods |
duke@435 | 750 | // |
duke@435 | 751 | |
duke@435 | 752 | MarkSweepPolicy::MarkSweepPolicy() { |
duke@435 | 753 | initialize_all(); |
duke@435 | 754 | } |
duke@435 | 755 | |
duke@435 | 756 | void MarkSweepPolicy::initialize_generations() { |
duke@435 | 757 | initialize_perm_generation(PermGen::MarkSweepCompact); |
duke@435 | 758 | _generations = new GenerationSpecPtr[number_of_generations()]; |
duke@435 | 759 | if (_generations == NULL) |
duke@435 | 760 | vm_exit_during_initialization("Unable to allocate gen spec"); |
duke@435 | 761 | |
duke@435 | 762 | if (UseParNewGC && ParallelGCThreads > 0) { |
duke@435 | 763 | _generations[0] = new GenerationSpec(Generation::ParNew, _initial_gen0_size, _max_gen0_size); |
duke@435 | 764 | } else { |
duke@435 | 765 | _generations[0] = new GenerationSpec(Generation::DefNew, _initial_gen0_size, _max_gen0_size); |
duke@435 | 766 | } |
duke@435 | 767 | _generations[1] = new GenerationSpec(Generation::MarkSweepCompact, _initial_gen1_size, _max_gen1_size); |
duke@435 | 768 | |
duke@435 | 769 | if (_generations[0] == NULL || _generations[1] == NULL) |
duke@435 | 770 | vm_exit_during_initialization("Unable to allocate gen spec"); |
duke@435 | 771 | } |
duke@435 | 772 | |
duke@435 | 773 | void MarkSweepPolicy::initialize_gc_policy_counters() { |
duke@435 | 774 | // initialize the policy counters - 2 collectors, 3 generations |
duke@435 | 775 | if (UseParNewGC && ParallelGCThreads > 0) { |
duke@435 | 776 | _gc_policy_counters = new GCPolicyCounters("ParNew:MSC", 2, 3); |
duke@435 | 777 | } |
duke@435 | 778 | else { |
duke@435 | 779 | _gc_policy_counters = new GCPolicyCounters("Copy:MSC", 2, 3); |
duke@435 | 780 | } |
duke@435 | 781 | } |