Thu, 28 Mar 2013 10:27:28 +0100
7014552: gc/lock/jni/jnilockXXX works too slow on 1-processor machine
Summary: Keep a counter of how many times we were stalled by the GC locker, add a diagnostic flag which sets the limit.
Reviewed-by: brutisso, ehelin, johnc
duke@435 | 1 | /* |
jcoomes@3541 | 2 | * Copyright (c) 2001, 2012, 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 | |
stefank@2314 | 25 | #include "precompiled.hpp" |
stefank@2314 | 26 | #include "gc_implementation/parallelScavenge/adjoiningGenerations.hpp" |
stefank@2314 | 27 | #include "gc_implementation/parallelScavenge/adjoiningVirtualSpaces.hpp" |
stefank@2314 | 28 | #include "gc_implementation/parallelScavenge/cardTableExtension.hpp" |
stefank@2314 | 29 | #include "gc_implementation/parallelScavenge/gcTaskManager.hpp" |
stefank@2314 | 30 | #include "gc_implementation/parallelScavenge/generationSizer.hpp" |
stefank@2314 | 31 | #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp" |
stefank@2314 | 32 | #include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp" |
stefank@2314 | 33 | #include "gc_implementation/parallelScavenge/psMarkSweep.hpp" |
stefank@2314 | 34 | #include "gc_implementation/parallelScavenge/psParallelCompact.hpp" |
stefank@2314 | 35 | #include "gc_implementation/parallelScavenge/psPromotionManager.hpp" |
stefank@2314 | 36 | #include "gc_implementation/parallelScavenge/psScavenge.hpp" |
stefank@2314 | 37 | #include "gc_implementation/parallelScavenge/vmPSOperations.hpp" |
stefank@2314 | 38 | #include "memory/gcLocker.inline.hpp" |
stefank@2314 | 39 | #include "oops/oop.inline.hpp" |
stefank@2314 | 40 | #include "runtime/handles.inline.hpp" |
stefank@2314 | 41 | #include "runtime/java.hpp" |
stefank@2314 | 42 | #include "runtime/vmThread.hpp" |
zgu@3900 | 43 | #include "services/memTracker.hpp" |
stefank@2314 | 44 | #include "utilities/vmError.hpp" |
duke@435 | 45 | |
duke@435 | 46 | PSYoungGen* ParallelScavengeHeap::_young_gen = NULL; |
duke@435 | 47 | PSOldGen* ParallelScavengeHeap::_old_gen = NULL; |
duke@435 | 48 | PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL; |
duke@435 | 49 | PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL; |
duke@435 | 50 | ParallelScavengeHeap* ParallelScavengeHeap::_psh = NULL; |
duke@435 | 51 | GCTaskManager* ParallelScavengeHeap::_gc_task_manager = NULL; |
duke@435 | 52 | |
duke@435 | 53 | static void trace_gen_sizes(const char* const str, |
duke@435 | 54 | size_t og_min, size_t og_max, |
duke@435 | 55 | size_t yg_min, size_t yg_max) |
duke@435 | 56 | { |
duke@435 | 57 | if (TracePageSizes) { |
duke@435 | 58 | tty->print_cr("%s: " SIZE_FORMAT "," SIZE_FORMAT " " |
duke@435 | 59 | SIZE_FORMAT "," SIZE_FORMAT " " |
duke@435 | 60 | SIZE_FORMAT, |
coleenp@4037 | 61 | str, |
duke@435 | 62 | og_min / K, og_max / K, |
duke@435 | 63 | yg_min / K, yg_max / K, |
coleenp@4037 | 64 | (og_max + yg_max) / K); |
duke@435 | 65 | } |
duke@435 | 66 | } |
duke@435 | 67 | |
duke@435 | 68 | jint ParallelScavengeHeap::initialize() { |
ysr@1601 | 69 | CollectedHeap::pre_initialize(); |
ysr@1601 | 70 | |
duke@435 | 71 | // Cannot be initialized until after the flags are parsed |
jmasa@1822 | 72 | // GenerationSizer flag_parser; |
jmasa@1822 | 73 | _collector_policy = new GenerationSizer(); |
duke@435 | 74 | |
jmasa@1822 | 75 | size_t yg_min_size = _collector_policy->min_young_gen_size(); |
jmasa@1822 | 76 | size_t yg_max_size = _collector_policy->max_young_gen_size(); |
jmasa@1822 | 77 | size_t og_min_size = _collector_policy->min_old_gen_size(); |
jmasa@1822 | 78 | size_t og_max_size = _collector_policy->max_old_gen_size(); |
duke@435 | 79 | |
duke@435 | 80 | trace_gen_sizes("ps heap raw", |
duke@435 | 81 | og_min_size, og_max_size, |
duke@435 | 82 | yg_min_size, yg_max_size); |
duke@435 | 83 | |
duke@435 | 84 | const size_t og_page_sz = os::page_size_for_region(yg_min_size + og_min_size, |
duke@435 | 85 | yg_max_size + og_max_size, |
duke@435 | 86 | 8); |
duke@435 | 87 | |
duke@435 | 88 | const size_t og_align = set_alignment(_old_gen_alignment, og_page_sz); |
duke@435 | 89 | const size_t yg_align = set_alignment(_young_gen_alignment, og_page_sz); |
duke@435 | 90 | |
duke@435 | 91 | // Update sizes to reflect the selected page size(s). |
duke@435 | 92 | // |
duke@435 | 93 | // NEEDS_CLEANUP. The default TwoGenerationCollectorPolicy uses NewRatio; it |
duke@435 | 94 | // should check UseAdaptiveSizePolicy. Changes from generationSizer could |
duke@435 | 95 | // move to the common code. |
duke@435 | 96 | yg_min_size = align_size_up(yg_min_size, yg_align); |
duke@435 | 97 | yg_max_size = align_size_up(yg_max_size, yg_align); |
jmasa@1822 | 98 | size_t yg_cur_size = |
jmasa@1822 | 99 | align_size_up(_collector_policy->young_gen_size(), yg_align); |
duke@435 | 100 | yg_cur_size = MAX2(yg_cur_size, yg_min_size); |
duke@435 | 101 | |
duke@435 | 102 | og_min_size = align_size_up(og_min_size, og_align); |
kvn@2558 | 103 | // Align old gen size down to preserve specified heap size. |
kvn@2558 | 104 | assert(og_align == yg_align, "sanity"); |
kvn@2558 | 105 | og_max_size = align_size_down(og_max_size, og_align); |
kvn@2558 | 106 | og_max_size = MAX2(og_max_size, og_min_size); |
jmasa@1822 | 107 | size_t og_cur_size = |
kvn@2558 | 108 | align_size_down(_collector_policy->old_gen_size(), og_align); |
duke@435 | 109 | og_cur_size = MAX2(og_cur_size, og_min_size); |
duke@435 | 110 | |
duke@435 | 111 | trace_gen_sizes("ps heap rnd", |
duke@435 | 112 | og_min_size, og_max_size, |
duke@435 | 113 | yg_min_size, yg_max_size); |
duke@435 | 114 | |
coleenp@4037 | 115 | const size_t heap_size = og_max_size + yg_max_size; |
kvn@1077 | 116 | |
coleenp@4037 | 117 | ReservedSpace heap_rs = Universe::reserve_heap(heap_size, og_align); |
kvn@1077 | 118 | |
zgu@3900 | 119 | MemTracker::record_virtual_memory_type((address)heap_rs.base(), mtJavaHeap); |
zgu@3900 | 120 | |
duke@435 | 121 | os::trace_page_sizes("ps main", og_min_size + yg_min_size, |
duke@435 | 122 | og_max_size + yg_max_size, og_page_sz, |
coleenp@4037 | 123 | heap_rs.base(), |
coleenp@4037 | 124 | heap_rs.size()); |
duke@435 | 125 | if (!heap_rs.is_reserved()) { |
duke@435 | 126 | vm_shutdown_during_initialization( |
duke@435 | 127 | "Could not reserve enough space for object heap"); |
duke@435 | 128 | return JNI_ENOMEM; |
duke@435 | 129 | } |
duke@435 | 130 | |
duke@435 | 131 | _reserved = MemRegion((HeapWord*)heap_rs.base(), |
duke@435 | 132 | (HeapWord*)(heap_rs.base() + heap_rs.size())); |
duke@435 | 133 | |
duke@435 | 134 | CardTableExtension* const barrier_set = new CardTableExtension(_reserved, 3); |
duke@435 | 135 | _barrier_set = barrier_set; |
duke@435 | 136 | oopDesc::set_bs(_barrier_set); |
duke@435 | 137 | if (_barrier_set == NULL) { |
duke@435 | 138 | vm_shutdown_during_initialization( |
duke@435 | 139 | "Could not reserve enough space for barrier set"); |
duke@435 | 140 | return JNI_ENOMEM; |
duke@435 | 141 | } |
duke@435 | 142 | |
duke@435 | 143 | // Initial young gen size is 4 Mb |
duke@435 | 144 | // |
duke@435 | 145 | // XXX - what about flag_parser.young_gen_size()? |
duke@435 | 146 | const size_t init_young_size = align_size_up(4 * M, yg_align); |
duke@435 | 147 | yg_cur_size = MAX2(MIN2(init_young_size, yg_max_size), yg_cur_size); |
duke@435 | 148 | |
duke@435 | 149 | // Make up the generations |
duke@435 | 150 | // Calculate the maximum size that a generation can grow. This |
duke@435 | 151 | // includes growth into the other generation. Note that the |
duke@435 | 152 | // parameter _max_gen_size is kept as the maximum |
duke@435 | 153 | // size of the generation as the boundaries currently stand. |
duke@435 | 154 | // _max_gen_size is still used as that value. |
duke@435 | 155 | double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0; |
duke@435 | 156 | double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0; |
duke@435 | 157 | |
coleenp@4037 | 158 | _gens = new AdjoiningGenerations(heap_rs, |
duke@435 | 159 | og_cur_size, |
duke@435 | 160 | og_min_size, |
duke@435 | 161 | og_max_size, |
duke@435 | 162 | yg_cur_size, |
duke@435 | 163 | yg_min_size, |
duke@435 | 164 | yg_max_size, |
duke@435 | 165 | yg_align); |
duke@435 | 166 | |
duke@435 | 167 | _old_gen = _gens->old_gen(); |
duke@435 | 168 | _young_gen = _gens->young_gen(); |
duke@435 | 169 | |
duke@435 | 170 | const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes(); |
duke@435 | 171 | const size_t old_capacity = _old_gen->capacity_in_bytes(); |
duke@435 | 172 | const size_t initial_promo_size = MIN2(eden_capacity, old_capacity); |
duke@435 | 173 | _size_policy = |
duke@435 | 174 | new PSAdaptiveSizePolicy(eden_capacity, |
duke@435 | 175 | initial_promo_size, |
duke@435 | 176 | young_gen()->to_space()->capacity_in_bytes(), |
jmasa@448 | 177 | intra_heap_alignment(), |
duke@435 | 178 | max_gc_pause_sec, |
duke@435 | 179 | max_gc_minor_pause_sec, |
duke@435 | 180 | GCTimeRatio |
duke@435 | 181 | ); |
duke@435 | 182 | |
duke@435 | 183 | assert(!UseAdaptiveGCBoundary || |
duke@435 | 184 | (old_gen()->virtual_space()->high_boundary() == |
duke@435 | 185 | young_gen()->virtual_space()->low_boundary()), |
duke@435 | 186 | "Boundaries must meet"); |
duke@435 | 187 | // initialize the policy counters - 2 collectors, 3 generations |
duke@435 | 188 | _gc_policy_counters = |
duke@435 | 189 | new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 3, _size_policy); |
duke@435 | 190 | _psh = this; |
duke@435 | 191 | |
duke@435 | 192 | // Set up the GCTaskManager |
duke@435 | 193 | _gc_task_manager = GCTaskManager::create(ParallelGCThreads); |
duke@435 | 194 | |
duke@435 | 195 | if (UseParallelOldGC && !PSParallelCompact::initialize()) { |
duke@435 | 196 | return JNI_ENOMEM; |
duke@435 | 197 | } |
duke@435 | 198 | |
duke@435 | 199 | return JNI_OK; |
duke@435 | 200 | } |
duke@435 | 201 | |
duke@435 | 202 | void ParallelScavengeHeap::post_initialize() { |
duke@435 | 203 | // Need to init the tenuring threshold |
duke@435 | 204 | PSScavenge::initialize(); |
duke@435 | 205 | if (UseParallelOldGC) { |
duke@435 | 206 | PSParallelCompact::post_initialize(); |
duke@435 | 207 | } else { |
duke@435 | 208 | PSMarkSweep::initialize(); |
duke@435 | 209 | } |
duke@435 | 210 | PSPromotionManager::initialize(); |
duke@435 | 211 | } |
duke@435 | 212 | |
duke@435 | 213 | void ParallelScavengeHeap::update_counters() { |
duke@435 | 214 | young_gen()->update_counters(); |
duke@435 | 215 | old_gen()->update_counters(); |
coleenp@4037 | 216 | MetaspaceCounters::update_performance_counters(); |
duke@435 | 217 | } |
duke@435 | 218 | |
duke@435 | 219 | size_t ParallelScavengeHeap::capacity() const { |
duke@435 | 220 | size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes(); |
duke@435 | 221 | return value; |
duke@435 | 222 | } |
duke@435 | 223 | |
duke@435 | 224 | size_t ParallelScavengeHeap::used() const { |
duke@435 | 225 | size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes(); |
duke@435 | 226 | return value; |
duke@435 | 227 | } |
duke@435 | 228 | |
duke@435 | 229 | bool ParallelScavengeHeap::is_maximal_no_gc() const { |
duke@435 | 230 | return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc(); |
duke@435 | 231 | } |
duke@435 | 232 | |
duke@435 | 233 | |
duke@435 | 234 | size_t ParallelScavengeHeap::max_capacity() const { |
duke@435 | 235 | size_t estimated = reserved_region().byte_size(); |
duke@435 | 236 | if (UseAdaptiveSizePolicy) { |
duke@435 | 237 | estimated -= _size_policy->max_survivor_size(young_gen()->max_size()); |
duke@435 | 238 | } else { |
duke@435 | 239 | estimated -= young_gen()->to_space()->capacity_in_bytes(); |
duke@435 | 240 | } |
duke@435 | 241 | return MAX2(estimated, capacity()); |
duke@435 | 242 | } |
duke@435 | 243 | |
duke@435 | 244 | bool ParallelScavengeHeap::is_in(const void* p) const { |
duke@435 | 245 | if (young_gen()->is_in(p)) { |
duke@435 | 246 | return true; |
duke@435 | 247 | } |
duke@435 | 248 | |
duke@435 | 249 | if (old_gen()->is_in(p)) { |
duke@435 | 250 | return true; |
duke@435 | 251 | } |
duke@435 | 252 | |
duke@435 | 253 | return false; |
duke@435 | 254 | } |
duke@435 | 255 | |
duke@435 | 256 | bool ParallelScavengeHeap::is_in_reserved(const void* p) const { |
duke@435 | 257 | if (young_gen()->is_in_reserved(p)) { |
duke@435 | 258 | return true; |
duke@435 | 259 | } |
duke@435 | 260 | |
duke@435 | 261 | if (old_gen()->is_in_reserved(p)) { |
duke@435 | 262 | return true; |
duke@435 | 263 | } |
duke@435 | 264 | |
duke@435 | 265 | return false; |
duke@435 | 266 | } |
duke@435 | 267 | |
jmasa@2909 | 268 | bool ParallelScavengeHeap::is_scavengable(const void* addr) { |
jmasa@2909 | 269 | return is_in_young((oop)addr); |
jmasa@2909 | 270 | } |
jmasa@2909 | 271 | |
jmasa@2909 | 272 | #ifdef ASSERT |
jmasa@2909 | 273 | // Don't implement this by using is_in_young(). This method is used |
jmasa@2909 | 274 | // in some cases to check that is_in_young() is correct. |
jmasa@2909 | 275 | bool ParallelScavengeHeap::is_in_partial_collection(const void *p) { |
jmasa@2909 | 276 | assert(is_in_reserved(p) || p == NULL, |
jmasa@2909 | 277 | "Does not work if address is non-null and outside of the heap"); |
coleenp@4037 | 278 | // The order of the generations is old (low addr), young (high addr) |
jmasa@2909 | 279 | return p >= old_gen()->reserved().end(); |
jmasa@2909 | 280 | } |
jmasa@2909 | 281 | #endif |
jmasa@2909 | 282 | |
duke@435 | 283 | // There are two levels of allocation policy here. |
duke@435 | 284 | // |
duke@435 | 285 | // When an allocation request fails, the requesting thread must invoke a VM |
duke@435 | 286 | // operation, transfer control to the VM thread, and await the results of a |
duke@435 | 287 | // garbage collection. That is quite expensive, and we should avoid doing it |
duke@435 | 288 | // multiple times if possible. |
duke@435 | 289 | // |
duke@435 | 290 | // To accomplish this, we have a basic allocation policy, and also a |
duke@435 | 291 | // failed allocation policy. |
duke@435 | 292 | // |
duke@435 | 293 | // The basic allocation policy controls how you allocate memory without |
duke@435 | 294 | // attempting garbage collection. It is okay to grab locks and |
duke@435 | 295 | // expand the heap, if that can be done without coming to a safepoint. |
duke@435 | 296 | // It is likely that the basic allocation policy will not be very |
duke@435 | 297 | // aggressive. |
duke@435 | 298 | // |
duke@435 | 299 | // The failed allocation policy is invoked from the VM thread after |
duke@435 | 300 | // the basic allocation policy is unable to satisfy a mem_allocate |
duke@435 | 301 | // request. This policy needs to cover the entire range of collection, |
duke@435 | 302 | // heap expansion, and out-of-memory conditions. It should make every |
duke@435 | 303 | // attempt to allocate the requested memory. |
duke@435 | 304 | |
duke@435 | 305 | // Basic allocation policy. Should never be called at a safepoint, or |
duke@435 | 306 | // from the VM thread. |
duke@435 | 307 | // |
duke@435 | 308 | // This method must handle cases where many mem_allocate requests fail |
duke@435 | 309 | // simultaneously. When that happens, only one VM operation will succeed, |
duke@435 | 310 | // and the rest will not be executed. For that reason, this method loops |
duke@435 | 311 | // during failed allocation attempts. If the java heap becomes exhausted, |
duke@435 | 312 | // we rely on the size_policy object to force a bail out. |
duke@435 | 313 | HeapWord* ParallelScavengeHeap::mem_allocate( |
duke@435 | 314 | size_t size, |
duke@435 | 315 | bool* gc_overhead_limit_was_exceeded) { |
duke@435 | 316 | assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint"); |
duke@435 | 317 | assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread"); |
duke@435 | 318 | assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); |
duke@435 | 319 | |
jmasa@1822 | 320 | // In general gc_overhead_limit_was_exceeded should be false so |
jmasa@1822 | 321 | // set it so here and reset it to true only if the gc time |
jmasa@1822 | 322 | // limit is being exceeded as checked below. |
jmasa@1822 | 323 | *gc_overhead_limit_was_exceeded = false; |
jmasa@1822 | 324 | |
tonyp@2971 | 325 | HeapWord* result = young_gen()->allocate(size); |
duke@435 | 326 | |
duke@435 | 327 | uint loop_count = 0; |
duke@435 | 328 | uint gc_count = 0; |
mgerdin@4853 | 329 | int gclocker_stalled_count = 0; |
duke@435 | 330 | |
duke@435 | 331 | while (result == NULL) { |
duke@435 | 332 | // We don't want to have multiple collections for a single filled generation. |
duke@435 | 333 | // To prevent this, each thread tracks the total_collections() value, and if |
duke@435 | 334 | // the count has changed, does not do a new collection. |
duke@435 | 335 | // |
duke@435 | 336 | // The collection count must be read only while holding the heap lock. VM |
duke@435 | 337 | // operations also hold the heap lock during collections. There is a lock |
duke@435 | 338 | // contention case where thread A blocks waiting on the Heap_lock, while |
duke@435 | 339 | // thread B is holding it doing a collection. When thread A gets the lock, |
duke@435 | 340 | // the collection count has already changed. To prevent duplicate collections, |
duke@435 | 341 | // The policy MUST attempt allocations during the same period it reads the |
duke@435 | 342 | // total_collections() value! |
duke@435 | 343 | { |
duke@435 | 344 | MutexLocker ml(Heap_lock); |
duke@435 | 345 | gc_count = Universe::heap()->total_collections(); |
duke@435 | 346 | |
tonyp@2971 | 347 | result = young_gen()->allocate(size); |
duke@435 | 348 | if (result != NULL) { |
duke@435 | 349 | return result; |
duke@435 | 350 | } |
jcoomes@3541 | 351 | |
jcoomes@3541 | 352 | // If certain conditions hold, try allocating from the old gen. |
jcoomes@3541 | 353 | result = mem_allocate_old_gen(size); |
jcoomes@3541 | 354 | if (result != NULL) { |
jcoomes@3541 | 355 | return result; |
duke@435 | 356 | } |
jcoomes@3541 | 357 | |
mgerdin@4853 | 358 | if (gclocker_stalled_count > GCLockerRetryAllocationCount) { |
mgerdin@4853 | 359 | return NULL; |
mgerdin@4853 | 360 | } |
mgerdin@4853 | 361 | |
jcoomes@3541 | 362 | // Failed to allocate without a gc. |
duke@435 | 363 | if (GC_locker::is_active_and_needs_gc()) { |
duke@435 | 364 | // If this thread is not in a jni critical section, we stall |
duke@435 | 365 | // the requestor until the critical section has cleared and |
duke@435 | 366 | // GC allowed. When the critical section clears, a GC is |
duke@435 | 367 | // initiated by the last thread exiting the critical section; so |
duke@435 | 368 | // we retry the allocation sequence from the beginning of the loop, |
duke@435 | 369 | // rather than causing more, now probably unnecessary, GC attempts. |
duke@435 | 370 | JavaThread* jthr = JavaThread::current(); |
duke@435 | 371 | if (!jthr->in_critical()) { |
duke@435 | 372 | MutexUnlocker mul(Heap_lock); |
duke@435 | 373 | GC_locker::stall_until_clear(); |
mgerdin@4853 | 374 | gclocker_stalled_count += 1; |
duke@435 | 375 | continue; |
duke@435 | 376 | } else { |
duke@435 | 377 | if (CheckJNICalls) { |
duke@435 | 378 | fatal("Possible deadlock due to allocating while" |
duke@435 | 379 | " in jni critical section"); |
duke@435 | 380 | } |
duke@435 | 381 | return NULL; |
duke@435 | 382 | } |
duke@435 | 383 | } |
duke@435 | 384 | } |
duke@435 | 385 | |
duke@435 | 386 | if (result == NULL) { |
duke@435 | 387 | // Generate a VM operation |
tonyp@2971 | 388 | VM_ParallelGCFailedAllocation op(size, gc_count); |
duke@435 | 389 | VMThread::execute(&op); |
duke@435 | 390 | |
duke@435 | 391 | // Did the VM operation execute? If so, return the result directly. |
duke@435 | 392 | // This prevents us from looping until time out on requests that can |
duke@435 | 393 | // not be satisfied. |
duke@435 | 394 | if (op.prologue_succeeded()) { |
duke@435 | 395 | assert(Universe::heap()->is_in_or_null(op.result()), |
duke@435 | 396 | "result not in heap"); |
duke@435 | 397 | |
duke@435 | 398 | // If GC was locked out during VM operation then retry allocation |
duke@435 | 399 | // and/or stall as necessary. |
duke@435 | 400 | if (op.gc_locked()) { |
duke@435 | 401 | assert(op.result() == NULL, "must be NULL if gc_locked() is true"); |
duke@435 | 402 | continue; // retry and/or stall as necessary |
duke@435 | 403 | } |
jmasa@1822 | 404 | |
jmasa@1822 | 405 | // Exit the loop if the gc time limit has been exceeded. |
jmasa@1822 | 406 | // The allocation must have failed above ("result" guarding |
jmasa@1822 | 407 | // this path is NULL) and the most recent collection has exceeded the |
jmasa@1822 | 408 | // gc overhead limit (although enough may have been collected to |
jmasa@1822 | 409 | // satisfy the allocation). Exit the loop so that an out-of-memory |
jmasa@1822 | 410 | // will be thrown (return a NULL ignoring the contents of |
jmasa@1822 | 411 | // op.result()), |
jmasa@1822 | 412 | // but clear gc_overhead_limit_exceeded so that the next collection |
jmasa@1822 | 413 | // starts with a clean slate (i.e., forgets about previous overhead |
jmasa@1822 | 414 | // excesses). Fill op.result() with a filler object so that the |
jmasa@1822 | 415 | // heap remains parsable. |
jmasa@1822 | 416 | const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded(); |
jmasa@1822 | 417 | const bool softrefs_clear = collector_policy()->all_soft_refs_clear(); |
jmasa@4743 | 418 | |
jmasa@1822 | 419 | if (limit_exceeded && softrefs_clear) { |
jmasa@1822 | 420 | *gc_overhead_limit_was_exceeded = true; |
jmasa@1822 | 421 | size_policy()->set_gc_overhead_limit_exceeded(false); |
jmasa@1822 | 422 | if (PrintGCDetails && Verbose) { |
jmasa@1822 | 423 | gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: " |
jmasa@1822 | 424 | "return NULL because gc_overhead_limit_exceeded is set"); |
jmasa@1822 | 425 | } |
jmasa@1822 | 426 | if (op.result() != NULL) { |
jmasa@1822 | 427 | CollectedHeap::fill_with_object(op.result(), size); |
jmasa@1822 | 428 | } |
jmasa@1822 | 429 | return NULL; |
duke@435 | 430 | } |
jmasa@1822 | 431 | |
duke@435 | 432 | return op.result(); |
duke@435 | 433 | } |
duke@435 | 434 | } |
duke@435 | 435 | |
duke@435 | 436 | // The policy object will prevent us from looping forever. If the |
duke@435 | 437 | // time spent in gc crosses a threshold, we will bail out. |
duke@435 | 438 | loop_count++; |
duke@435 | 439 | if ((result == NULL) && (QueuedAllocationWarningCount > 0) && |
duke@435 | 440 | (loop_count % QueuedAllocationWarningCount == 0)) { |
duke@435 | 441 | warning("ParallelScavengeHeap::mem_allocate retries %d times \n\t" |
tonyp@2971 | 442 | " size=%d", loop_count, size); |
duke@435 | 443 | } |
duke@435 | 444 | } |
duke@435 | 445 | |
duke@435 | 446 | return result; |
duke@435 | 447 | } |
duke@435 | 448 | |
jcoomes@3541 | 449 | // A "death march" is a series of ultra-slow allocations in which a full gc is |
jcoomes@3541 | 450 | // done before each allocation, and after the full gc the allocation still |
jcoomes@3541 | 451 | // cannot be satisfied from the young gen. This routine detects that condition; |
jcoomes@3541 | 452 | // it should be called after a full gc has been done and the allocation |
jcoomes@3541 | 453 | // attempted from the young gen. The parameter 'addr' should be the result of |
jcoomes@3541 | 454 | // that young gen allocation attempt. |
jcoomes@3541 | 455 | void |
jcoomes@3541 | 456 | ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) { |
jcoomes@3541 | 457 | if (addr != NULL) { |
jcoomes@3541 | 458 | _death_march_count = 0; // death march has ended |
jcoomes@3541 | 459 | } else if (_death_march_count == 0) { |
jcoomes@3541 | 460 | if (should_alloc_in_eden(size)) { |
jcoomes@3541 | 461 | _death_march_count = 1; // death march has started |
jcoomes@3541 | 462 | } |
jcoomes@3541 | 463 | } |
jcoomes@3541 | 464 | } |
jcoomes@3541 | 465 | |
jcoomes@3541 | 466 | HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) { |
jcoomes@3541 | 467 | if (!should_alloc_in_eden(size) || GC_locker::is_active_and_needs_gc()) { |
jcoomes@3541 | 468 | // Size is too big for eden, or gc is locked out. |
jcoomes@3541 | 469 | return old_gen()->allocate(size); |
jcoomes@3541 | 470 | } |
jcoomes@3541 | 471 | |
jcoomes@3541 | 472 | // If a "death march" is in progress, allocate from the old gen a limited |
jcoomes@3541 | 473 | // number of times before doing a GC. |
jcoomes@3541 | 474 | if (_death_march_count > 0) { |
jcoomes@3541 | 475 | if (_death_march_count < 64) { |
jcoomes@3541 | 476 | ++_death_march_count; |
jcoomes@3541 | 477 | return old_gen()->allocate(size); |
jcoomes@3541 | 478 | } else { |
jcoomes@3541 | 479 | _death_march_count = 0; |
jcoomes@3541 | 480 | } |
jcoomes@3541 | 481 | } |
jcoomes@3541 | 482 | return NULL; |
jcoomes@3541 | 483 | } |
jcoomes@3541 | 484 | |
coleenp@4037 | 485 | void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) { |
coleenp@4037 | 486 | if (UseParallelOldGC) { |
coleenp@4037 | 487 | // The do_full_collection() parameter clear_all_soft_refs |
coleenp@4037 | 488 | // is interpreted here as maximum_compaction which will |
coleenp@4037 | 489 | // cause SoftRefs to be cleared. |
coleenp@4037 | 490 | bool maximum_compaction = clear_all_soft_refs; |
coleenp@4037 | 491 | PSParallelCompact::invoke(maximum_compaction); |
coleenp@4037 | 492 | } else { |
coleenp@4037 | 493 | PSMarkSweep::invoke(clear_all_soft_refs); |
coleenp@4037 | 494 | } |
coleenp@4037 | 495 | } |
coleenp@4037 | 496 | |
duke@435 | 497 | // Failed allocation policy. Must be called from the VM thread, and |
duke@435 | 498 | // only at a safepoint! Note that this method has policy for allocation |
duke@435 | 499 | // flow, and NOT collection policy. So we do not check for gc collection |
duke@435 | 500 | // time over limit here, that is the responsibility of the heap specific |
duke@435 | 501 | // collection methods. This method decides where to attempt allocations, |
duke@435 | 502 | // and when to attempt collections, but no collection specific policy. |
tonyp@2971 | 503 | HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) { |
duke@435 | 504 | assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); |
duke@435 | 505 | assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); |
duke@435 | 506 | assert(!Universe::heap()->is_gc_active(), "not reentrant"); |
duke@435 | 507 | assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); |
duke@435 | 508 | |
jcoomes@3541 | 509 | // We assume that allocation in eden will fail unless we collect. |
duke@435 | 510 | |
duke@435 | 511 | // First level allocation failure, scavenge and allocate in young gen. |
duke@435 | 512 | GCCauseSetter gccs(this, GCCause::_allocation_failure); |
jcoomes@3541 | 513 | const bool invoked_full_gc = PSScavenge::invoke(); |
tonyp@2971 | 514 | HeapWord* result = young_gen()->allocate(size); |
duke@435 | 515 | |
duke@435 | 516 | // Second level allocation failure. |
duke@435 | 517 | // Mark sweep and allocate in young generation. |
jcoomes@3541 | 518 | if (result == NULL && !invoked_full_gc) { |
coleenp@4037 | 519 | do_full_collection(false); |
jcoomes@3541 | 520 | result = young_gen()->allocate(size); |
duke@435 | 521 | } |
duke@435 | 522 | |
jcoomes@3541 | 523 | death_march_check(result, size); |
jcoomes@3541 | 524 | |
duke@435 | 525 | // Third level allocation failure. |
duke@435 | 526 | // After mark sweep and young generation allocation failure, |
duke@435 | 527 | // allocate in old generation. |
tonyp@2971 | 528 | if (result == NULL) { |
tonyp@2971 | 529 | result = old_gen()->allocate(size); |
duke@435 | 530 | } |
duke@435 | 531 | |
duke@435 | 532 | // Fourth level allocation failure. We're running out of memory. |
duke@435 | 533 | // More complete mark sweep and allocate in young generation. |
duke@435 | 534 | if (result == NULL) { |
coleenp@4037 | 535 | do_full_collection(true); |
tonyp@2971 | 536 | result = young_gen()->allocate(size); |
duke@435 | 537 | } |
duke@435 | 538 | |
duke@435 | 539 | // Fifth level allocation failure. |
duke@435 | 540 | // After more complete mark sweep, allocate in old generation. |
tonyp@2971 | 541 | if (result == NULL) { |
tonyp@2971 | 542 | result = old_gen()->allocate(size); |
duke@435 | 543 | } |
duke@435 | 544 | |
duke@435 | 545 | return result; |
duke@435 | 546 | } |
duke@435 | 547 | |
duke@435 | 548 | void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) { |
duke@435 | 549 | CollectedHeap::ensure_parsability(retire_tlabs); |
duke@435 | 550 | young_gen()->eden_space()->ensure_parsability(); |
duke@435 | 551 | } |
duke@435 | 552 | |
duke@435 | 553 | size_t ParallelScavengeHeap::unsafe_max_alloc() { |
duke@435 | 554 | return young_gen()->eden_space()->free_in_bytes(); |
duke@435 | 555 | } |
duke@435 | 556 | |
duke@435 | 557 | size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const { |
duke@435 | 558 | return young_gen()->eden_space()->tlab_capacity(thr); |
duke@435 | 559 | } |
duke@435 | 560 | |
duke@435 | 561 | size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const { |
duke@435 | 562 | return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr); |
duke@435 | 563 | } |
duke@435 | 564 | |
duke@435 | 565 | HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t size) { |
tonyp@2971 | 566 | return young_gen()->allocate(size); |
duke@435 | 567 | } |
duke@435 | 568 | |
duke@435 | 569 | void ParallelScavengeHeap::accumulate_statistics_all_tlabs() { |
duke@435 | 570 | CollectedHeap::accumulate_statistics_all_tlabs(); |
duke@435 | 571 | } |
duke@435 | 572 | |
duke@435 | 573 | void ParallelScavengeHeap::resize_all_tlabs() { |
duke@435 | 574 | CollectedHeap::resize_all_tlabs(); |
duke@435 | 575 | } |
duke@435 | 576 | |
ysr@1462 | 577 | bool ParallelScavengeHeap::can_elide_initializing_store_barrier(oop new_obj) { |
ysr@1462 | 578 | // We don't need barriers for stores to objects in the |
ysr@1462 | 579 | // young gen and, a fortiori, for initializing stores to |
ysr@1462 | 580 | // objects therein. |
ysr@1462 | 581 | return is_in_young(new_obj); |
ysr@1462 | 582 | } |
ysr@1462 | 583 | |
duke@435 | 584 | // This method is used by System.gc() and JVMTI. |
duke@435 | 585 | void ParallelScavengeHeap::collect(GCCause::Cause cause) { |
duke@435 | 586 | assert(!Heap_lock->owned_by_self(), |
duke@435 | 587 | "this thread should not own the Heap_lock"); |
duke@435 | 588 | |
duke@435 | 589 | unsigned int gc_count = 0; |
duke@435 | 590 | unsigned int full_gc_count = 0; |
duke@435 | 591 | { |
duke@435 | 592 | MutexLocker ml(Heap_lock); |
duke@435 | 593 | // This value is guarded by the Heap_lock |
duke@435 | 594 | gc_count = Universe::heap()->total_collections(); |
duke@435 | 595 | full_gc_count = Universe::heap()->total_full_collections(); |
duke@435 | 596 | } |
duke@435 | 597 | |
duke@435 | 598 | VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause); |
duke@435 | 599 | VMThread::execute(&op); |
duke@435 | 600 | } |
duke@435 | 601 | |
coleenp@4037 | 602 | void ParallelScavengeHeap::oop_iterate(ExtendedOopClosure* cl) { |
duke@435 | 603 | Unimplemented(); |
duke@435 | 604 | } |
duke@435 | 605 | |
duke@435 | 606 | void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) { |
duke@435 | 607 | young_gen()->object_iterate(cl); |
duke@435 | 608 | old_gen()->object_iterate(cl); |
duke@435 | 609 | } |
duke@435 | 610 | |
duke@435 | 611 | |
duke@435 | 612 | HeapWord* ParallelScavengeHeap::block_start(const void* addr) const { |
duke@435 | 613 | if (young_gen()->is_in_reserved(addr)) { |
duke@435 | 614 | assert(young_gen()->is_in(addr), |
duke@435 | 615 | "addr should be in allocated part of young gen"); |
never@2262 | 616 | // called from os::print_location by find or VMError |
never@2262 | 617 | if (Debugging || VMError::fatal_error_in_progress()) return NULL; |
duke@435 | 618 | Unimplemented(); |
duke@435 | 619 | } else if (old_gen()->is_in_reserved(addr)) { |
duke@435 | 620 | assert(old_gen()->is_in(addr), |
duke@435 | 621 | "addr should be in allocated part of old gen"); |
duke@435 | 622 | return old_gen()->start_array()->object_start((HeapWord*)addr); |
duke@435 | 623 | } |
duke@435 | 624 | return 0; |
duke@435 | 625 | } |
duke@435 | 626 | |
duke@435 | 627 | size_t ParallelScavengeHeap::block_size(const HeapWord* addr) const { |
duke@435 | 628 | return oop(addr)->size(); |
duke@435 | 629 | } |
duke@435 | 630 | |
duke@435 | 631 | bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const { |
duke@435 | 632 | return block_start(addr) == addr; |
duke@435 | 633 | } |
duke@435 | 634 | |
duke@435 | 635 | jlong ParallelScavengeHeap::millis_since_last_gc() { |
duke@435 | 636 | return UseParallelOldGC ? |
duke@435 | 637 | PSParallelCompact::millis_since_last_gc() : |
duke@435 | 638 | PSMarkSweep::millis_since_last_gc(); |
duke@435 | 639 | } |
duke@435 | 640 | |
duke@435 | 641 | void ParallelScavengeHeap::prepare_for_verify() { |
duke@435 | 642 | ensure_parsability(false); // no need to retire TLABs for verification |
duke@435 | 643 | } |
duke@435 | 644 | |
duke@435 | 645 | void ParallelScavengeHeap::print_on(outputStream* st) const { |
duke@435 | 646 | young_gen()->print_on(st); |
duke@435 | 647 | old_gen()->print_on(st); |
coleenp@4037 | 648 | MetaspaceAux::print_on(st); |
duke@435 | 649 | } |
duke@435 | 650 | |
duke@435 | 651 | void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const { |
duke@435 | 652 | PSScavenge::gc_task_manager()->threads_do(tc); |
duke@435 | 653 | } |
duke@435 | 654 | |
duke@435 | 655 | void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const { |
duke@435 | 656 | PSScavenge::gc_task_manager()->print_threads_on(st); |
duke@435 | 657 | } |
duke@435 | 658 | |
duke@435 | 659 | void ParallelScavengeHeap::print_tracing_info() const { |
duke@435 | 660 | if (TraceGen0Time) { |
duke@435 | 661 | double time = PSScavenge::accumulated_time()->seconds(); |
duke@435 | 662 | tty->print_cr("[Accumulated GC generation 0 time %3.7f secs]", time); |
duke@435 | 663 | } |
duke@435 | 664 | if (TraceGen1Time) { |
tschatzl@4785 | 665 | double time = UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweep::accumulated_time()->seconds(); |
duke@435 | 666 | tty->print_cr("[Accumulated GC generation 1 time %3.7f secs]", time); |
duke@435 | 667 | } |
duke@435 | 668 | } |
duke@435 | 669 | |
duke@435 | 670 | |
brutisso@3711 | 671 | void ParallelScavengeHeap::verify(bool silent, VerifyOption option /* ignored */) { |
duke@435 | 672 | // Why do we need the total_collections()-filter below? |
duke@435 | 673 | if (total_collections() > 0) { |
duke@435 | 674 | if (!silent) { |
duke@435 | 675 | gclog_or_tty->print("tenured "); |
duke@435 | 676 | } |
brutisso@3711 | 677 | old_gen()->verify(); |
duke@435 | 678 | |
duke@435 | 679 | if (!silent) { |
duke@435 | 680 | gclog_or_tty->print("eden "); |
duke@435 | 681 | } |
brutisso@3711 | 682 | young_gen()->verify(); |
duke@435 | 683 | } |
duke@435 | 684 | } |
duke@435 | 685 | |
duke@435 | 686 | void ParallelScavengeHeap::print_heap_change(size_t prev_used) { |
duke@435 | 687 | if (PrintGCDetails && Verbose) { |
duke@435 | 688 | gclog_or_tty->print(" " SIZE_FORMAT |
duke@435 | 689 | "->" SIZE_FORMAT |
duke@435 | 690 | "(" SIZE_FORMAT ")", |
duke@435 | 691 | prev_used, used(), capacity()); |
duke@435 | 692 | } else { |
duke@435 | 693 | gclog_or_tty->print(" " SIZE_FORMAT "K" |
duke@435 | 694 | "->" SIZE_FORMAT "K" |
duke@435 | 695 | "(" SIZE_FORMAT "K)", |
duke@435 | 696 | prev_used / K, used() / K, capacity() / K); |
duke@435 | 697 | } |
duke@435 | 698 | } |
duke@435 | 699 | |
duke@435 | 700 | ParallelScavengeHeap* ParallelScavengeHeap::heap() { |
duke@435 | 701 | assert(_psh != NULL, "Uninitialized access to ParallelScavengeHeap::heap()"); |
duke@435 | 702 | assert(_psh->kind() == CollectedHeap::ParallelScavengeHeap, "not a parallel scavenge heap"); |
duke@435 | 703 | return _psh; |
duke@435 | 704 | } |
duke@435 | 705 | |
duke@435 | 706 | // Before delegating the resize to the young generation, |
duke@435 | 707 | // the reserved space for the young and old generations |
duke@435 | 708 | // may be changed to accomodate the desired resize. |
duke@435 | 709 | void ParallelScavengeHeap::resize_young_gen(size_t eden_size, |
duke@435 | 710 | size_t survivor_size) { |
duke@435 | 711 | if (UseAdaptiveGCBoundary) { |
duke@435 | 712 | if (size_policy()->bytes_absorbed_from_eden() != 0) { |
duke@435 | 713 | size_policy()->reset_bytes_absorbed_from_eden(); |
duke@435 | 714 | return; // The generation changed size already. |
duke@435 | 715 | } |
duke@435 | 716 | gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size); |
duke@435 | 717 | } |
duke@435 | 718 | |
duke@435 | 719 | // Delegate the resize to the generation. |
duke@435 | 720 | _young_gen->resize(eden_size, survivor_size); |
duke@435 | 721 | } |
duke@435 | 722 | |
duke@435 | 723 | // Before delegating the resize to the old generation, |
duke@435 | 724 | // the reserved space for the young and old generations |
duke@435 | 725 | // may be changed to accomodate the desired resize. |
duke@435 | 726 | void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) { |
duke@435 | 727 | if (UseAdaptiveGCBoundary) { |
duke@435 | 728 | if (size_policy()->bytes_absorbed_from_eden() != 0) { |
duke@435 | 729 | size_policy()->reset_bytes_absorbed_from_eden(); |
duke@435 | 730 | return; // The generation changed size already. |
duke@435 | 731 | } |
duke@435 | 732 | gens()->adjust_boundary_for_old_gen_needs(desired_free_space); |
duke@435 | 733 | } |
duke@435 | 734 | |
duke@435 | 735 | // Delegate the resize to the generation. |
duke@435 | 736 | _old_gen->resize(desired_free_space); |
duke@435 | 737 | } |
jmasa@698 | 738 | |
jrose@1424 | 739 | ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() { |
jrose@1424 | 740 | // nothing particular |
jrose@1424 | 741 | } |
jrose@1424 | 742 | |
jrose@1424 | 743 | ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() { |
jrose@1424 | 744 | // nothing particular |
jrose@1424 | 745 | } |
jrose@1424 | 746 | |
jmasa@698 | 747 | #ifndef PRODUCT |
jmasa@698 | 748 | void ParallelScavengeHeap::record_gen_tops_before_GC() { |
jmasa@698 | 749 | if (ZapUnusedHeapArea) { |
jmasa@698 | 750 | young_gen()->record_spaces_top(); |
jmasa@698 | 751 | old_gen()->record_spaces_top(); |
jmasa@698 | 752 | } |
jmasa@698 | 753 | } |
jmasa@698 | 754 | |
jmasa@698 | 755 | void ParallelScavengeHeap::gen_mangle_unused_area() { |
jmasa@698 | 756 | if (ZapUnusedHeapArea) { |
jmasa@698 | 757 | young_gen()->eden_space()->mangle_unused_area(); |
jmasa@698 | 758 | young_gen()->to_space()->mangle_unused_area(); |
jmasa@698 | 759 | young_gen()->from_space()->mangle_unused_area(); |
jmasa@698 | 760 | old_gen()->object_space()->mangle_unused_area(); |
jmasa@698 | 761 | } |
jmasa@698 | 762 | } |
jmasa@698 | 763 | #endif |