1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/psPromotionManager.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,344 @@
1.4 +/*
1.5 + * Copyright (c) 2002, 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
1.30 +#include "gc_implementation/parallelScavenge/psOldGen.hpp"
1.31 +#include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
1.32 +#include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
1.33 +#include "gc_implementation/shared/gcTrace.hpp"
1.34 +#include "gc_implementation/shared/mutableSpace.hpp"
1.35 +#include "memory/allocation.inline.hpp"
1.36 +#include "memory/memRegion.hpp"
1.37 +#include "memory/padded.inline.hpp"
1.38 +#include "oops/oop.inline.hpp"
1.39 +#include "oops/oop.psgc.inline.hpp"
1.40 +
1.41 +PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
1.42 +
1.43 +PaddedEnd<PSPromotionManager>* PSPromotionManager::_manager_array = NULL;
1.44 +OopStarTaskQueueSet* PSPromotionManager::_stack_array_depth = NULL;
1.45 +PSOldGen* PSPromotionManager::_old_gen = NULL;
1.46 +MutableSpace* PSPromotionManager::_young_space = NULL;
1.47 +
1.48 +void PSPromotionManager::initialize() {
1.49 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.50 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.51 +
1.52 + _old_gen = heap->old_gen();
1.53 + _young_space = heap->young_gen()->to_space();
1.54 +
1.55 + // To prevent false sharing, we pad the PSPromotionManagers
1.56 + // and make sure that the first instance starts at a cache line.
1.57 + assert(_manager_array == NULL, "Attempt to initialize twice");
1.58 + _manager_array = PaddedArray<PSPromotionManager, mtGC>::create_unfreeable(ParallelGCThreads + 1);
1.59 + guarantee(_manager_array != NULL, "Could not initialize promotion manager");
1.60 +
1.61 + _stack_array_depth = new OopStarTaskQueueSet(ParallelGCThreads);
1.62 + guarantee(_stack_array_depth != NULL, "Could not initialize promotion manager");
1.63 +
1.64 + // Create and register the PSPromotionManager(s) for the worker threads.
1.65 + for(uint i=0; i<ParallelGCThreads; i++) {
1.66 + stack_array_depth()->register_queue(i, _manager_array[i].claimed_stack_depth());
1.67 + }
1.68 + // The VMThread gets its own PSPromotionManager, which is not available
1.69 + // for work stealing.
1.70 +}
1.71 +
1.72 +PSPromotionManager* PSPromotionManager::gc_thread_promotion_manager(int index) {
1.73 + assert(index >= 0 && index < (int)ParallelGCThreads, "index out of range");
1.74 + assert(_manager_array != NULL, "Sanity");
1.75 + return &_manager_array[index];
1.76 +}
1.77 +
1.78 +PSPromotionManager* PSPromotionManager::vm_thread_promotion_manager() {
1.79 + assert(_manager_array != NULL, "Sanity");
1.80 + return &_manager_array[ParallelGCThreads];
1.81 +}
1.82 +
1.83 +void PSPromotionManager::pre_scavenge() {
1.84 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.85 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.86 +
1.87 + _young_space = heap->young_gen()->to_space();
1.88 +
1.89 + for(uint i=0; i<ParallelGCThreads+1; i++) {
1.90 + manager_array(i)->reset();
1.91 + }
1.92 +}
1.93 +
1.94 +bool PSPromotionManager::post_scavenge(YoungGCTracer& gc_tracer) {
1.95 + bool promotion_failure_occurred = false;
1.96 +
1.97 + TASKQUEUE_STATS_ONLY(if (PrintGCDetails && ParallelGCVerbose) print_stats());
1.98 + for (uint i = 0; i < ParallelGCThreads + 1; i++) {
1.99 + PSPromotionManager* manager = manager_array(i);
1.100 + assert(manager->claimed_stack_depth()->is_empty(), "should be empty");
1.101 + if (manager->_promotion_failed_info.has_failed()) {
1.102 + gc_tracer.report_promotion_failed(manager->_promotion_failed_info);
1.103 + promotion_failure_occurred = true;
1.104 + }
1.105 + manager->flush_labs();
1.106 + }
1.107 + return promotion_failure_occurred;
1.108 +}
1.109 +
1.110 +#if TASKQUEUE_STATS
1.111 +void
1.112 +PSPromotionManager::print_taskqueue_stats(uint i) const {
1.113 + tty->print("%3u ", i);
1.114 + _claimed_stack_depth.stats.print();
1.115 + tty->cr();
1.116 +}
1.117 +
1.118 +void
1.119 +PSPromotionManager::print_local_stats(uint i) const {
1.120 + #define FMT " " SIZE_FORMAT_W(10)
1.121 + tty->print_cr("%3u" FMT FMT FMT FMT, i, _masked_pushes, _masked_steals,
1.122 + _arrays_chunked, _array_chunks_processed);
1.123 + #undef FMT
1.124 +}
1.125 +
1.126 +static const char* const pm_stats_hdr[] = {
1.127 + " --------masked------- arrays array",
1.128 + "thr push steal chunked chunks",
1.129 + "--- ---------- ---------- ---------- ----------"
1.130 +};
1.131 +
1.132 +void
1.133 +PSPromotionManager::print_stats() {
1.134 + tty->print_cr("== GC Tasks Stats, GC %3d",
1.135 + Universe::heap()->total_collections());
1.136 +
1.137 + tty->print("thr "); TaskQueueStats::print_header(1); tty->cr();
1.138 + tty->print("--- "); TaskQueueStats::print_header(2); tty->cr();
1.139 + for (uint i = 0; i < ParallelGCThreads + 1; ++i) {
1.140 + manager_array(i)->print_taskqueue_stats(i);
1.141 + }
1.142 +
1.143 + const uint hlines = sizeof(pm_stats_hdr) / sizeof(pm_stats_hdr[0]);
1.144 + for (uint i = 0; i < hlines; ++i) tty->print_cr("%s", pm_stats_hdr[i]);
1.145 + for (uint i = 0; i < ParallelGCThreads + 1; ++i) {
1.146 + manager_array(i)->print_local_stats(i);
1.147 + }
1.148 +}
1.149 +
1.150 +void
1.151 +PSPromotionManager::reset_stats() {
1.152 + claimed_stack_depth()->stats.reset();
1.153 + _masked_pushes = _masked_steals = 0;
1.154 + _arrays_chunked = _array_chunks_processed = 0;
1.155 +}
1.156 +#endif // TASKQUEUE_STATS
1.157 +
1.158 +PSPromotionManager::PSPromotionManager() {
1.159 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.160 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.161 +
1.162 + // We set the old lab's start array.
1.163 + _old_lab.set_start_array(old_gen()->start_array());
1.164 +
1.165 + uint queue_size;
1.166 + claimed_stack_depth()->initialize();
1.167 + queue_size = claimed_stack_depth()->max_elems();
1.168 +
1.169 + _totally_drain = (ParallelGCThreads == 1) || (GCDrainStackTargetSize == 0);
1.170 + if (_totally_drain) {
1.171 + _target_stack_size = 0;
1.172 + } else {
1.173 + // don't let the target stack size to be more than 1/4 of the entries
1.174 + _target_stack_size = (uint) MIN2((uint) GCDrainStackTargetSize,
1.175 + (uint) (queue_size / 4));
1.176 + }
1.177 +
1.178 + _array_chunk_size = ParGCArrayScanChunk;
1.179 + // let's choose 1.5x the chunk size
1.180 + _min_array_size_for_chunking = 3 * _array_chunk_size / 2;
1.181 +
1.182 + reset();
1.183 +}
1.184 +
1.185 +void PSPromotionManager::reset() {
1.186 + assert(stacks_empty(), "reset of non-empty stack");
1.187 +
1.188 + // We need to get an assert in here to make sure the labs are always flushed.
1.189 +
1.190 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.191 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.192 +
1.193 + // Do not prefill the LAB's, save heap wastage!
1.194 + HeapWord* lab_base = young_space()->top();
1.195 + _young_lab.initialize(MemRegion(lab_base, (size_t)0));
1.196 + _young_gen_is_full = false;
1.197 +
1.198 + lab_base = old_gen()->object_space()->top();
1.199 + _old_lab.initialize(MemRegion(lab_base, (size_t)0));
1.200 + _old_gen_is_full = false;
1.201 +
1.202 + _promotion_failed_info.reset();
1.203 +
1.204 + TASKQUEUE_STATS_ONLY(reset_stats());
1.205 +}
1.206 +
1.207 +
1.208 +void PSPromotionManager::drain_stacks_depth(bool totally_drain) {
1.209 + totally_drain = totally_drain || _totally_drain;
1.210 +
1.211 +#ifdef ASSERT
1.212 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.213 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.214 + MutableSpace* to_space = heap->young_gen()->to_space();
1.215 + MutableSpace* old_space = heap->old_gen()->object_space();
1.216 +#endif /* ASSERT */
1.217 +
1.218 + OopStarTaskQueue* const tq = claimed_stack_depth();
1.219 + do {
1.220 + StarTask p;
1.221 +
1.222 + // Drain overflow stack first, so other threads can steal from
1.223 + // claimed stack while we work.
1.224 + while (tq->pop_overflow(p)) {
1.225 + process_popped_location_depth(p);
1.226 + }
1.227 +
1.228 + if (totally_drain) {
1.229 + while (tq->pop_local(p)) {
1.230 + process_popped_location_depth(p);
1.231 + }
1.232 + } else {
1.233 + while (tq->size() > _target_stack_size && tq->pop_local(p)) {
1.234 + process_popped_location_depth(p);
1.235 + }
1.236 + }
1.237 + } while (totally_drain && !tq->taskqueue_empty() || !tq->overflow_empty());
1.238 +
1.239 + assert(!totally_drain || tq->taskqueue_empty(), "Sanity");
1.240 + assert(totally_drain || tq->size() <= _target_stack_size, "Sanity");
1.241 + assert(tq->overflow_empty(), "Sanity");
1.242 +}
1.243 +
1.244 +void PSPromotionManager::flush_labs() {
1.245 + assert(stacks_empty(), "Attempt to flush lab with live stack");
1.246 +
1.247 + // If either promotion lab fills up, we can flush the
1.248 + // lab but not refill it, so check first.
1.249 + assert(!_young_lab.is_flushed() || _young_gen_is_full, "Sanity");
1.250 + if (!_young_lab.is_flushed())
1.251 + _young_lab.flush();
1.252 +
1.253 + assert(!_old_lab.is_flushed() || _old_gen_is_full, "Sanity");
1.254 + if (!_old_lab.is_flushed())
1.255 + _old_lab.flush();
1.256 +
1.257 + // Let PSScavenge know if we overflowed
1.258 + if (_young_gen_is_full) {
1.259 + PSScavenge::set_survivor_overflow(true);
1.260 + }
1.261 +}
1.262 +
1.263 +template <class T> void PSPromotionManager::process_array_chunk_work(
1.264 + oop obj,
1.265 + int start, int end) {
1.266 + assert(start <= end, "invariant");
1.267 + T* const base = (T*)objArrayOop(obj)->base();
1.268 + T* p = base + start;
1.269 + T* const chunk_end = base + end;
1.270 + while (p < chunk_end) {
1.271 + if (PSScavenge::should_scavenge(p)) {
1.272 + claim_or_forward_depth(p);
1.273 + }
1.274 + ++p;
1.275 + }
1.276 +}
1.277 +
1.278 +void PSPromotionManager::process_array_chunk(oop old) {
1.279 + assert(PSChunkLargeArrays, "invariant");
1.280 + assert(old->is_objArray(), "invariant");
1.281 + assert(old->is_forwarded(), "invariant");
1.282 +
1.283 + TASKQUEUE_STATS_ONLY(++_array_chunks_processed);
1.284 +
1.285 + oop const obj = old->forwardee();
1.286 +
1.287 + int start;
1.288 + int const end = arrayOop(old)->length();
1.289 + if (end > (int) _min_array_size_for_chunking) {
1.290 + // we'll chunk more
1.291 + start = end - _array_chunk_size;
1.292 + assert(start > 0, "invariant");
1.293 + arrayOop(old)->set_length(start);
1.294 + push_depth(mask_chunked_array_oop(old));
1.295 + TASKQUEUE_STATS_ONLY(++_masked_pushes);
1.296 + } else {
1.297 + // this is the final chunk for this array
1.298 + start = 0;
1.299 + int const actual_length = arrayOop(obj)->length();
1.300 + arrayOop(old)->set_length(actual_length);
1.301 + }
1.302 +
1.303 + if (UseCompressedOops) {
1.304 + process_array_chunk_work<narrowOop>(obj, start, end);
1.305 + } else {
1.306 + process_array_chunk_work<oop>(obj, start, end);
1.307 + }
1.308 +}
1.309 +
1.310 +oop PSPromotionManager::oop_promotion_failed(oop obj, markOop obj_mark) {
1.311 + assert(_old_gen_is_full || PromotionFailureALot, "Sanity");
1.312 +
1.313 + // Attempt to CAS in the header.
1.314 + // This tests if the header is still the same as when
1.315 + // this started. If it is the same (i.e., no forwarding
1.316 + // pointer has been installed), then this thread owns
1.317 + // it.
1.318 + if (obj->cas_forward_to(obj, obj_mark)) {
1.319 + // We won any races, we "own" this object.
1.320 + assert(obj == obj->forwardee(), "Sanity");
1.321 +
1.322 + _promotion_failed_info.register_copy_failure(obj->size());
1.323 +
1.324 + obj->push_contents(this);
1.325 +
1.326 + // Save the mark if needed
1.327 + PSScavenge::oop_promotion_failed(obj, obj_mark);
1.328 + } else {
1.329 + // We lost, someone else "owns" this object
1.330 + guarantee(obj->is_forwarded(), "Object must be forwarded if the cas failed.");
1.331 +
1.332 + // No unallocation to worry about.
1.333 + obj = obj->forwardee();
1.334 + }
1.335 +
1.336 +#ifndef PRODUCT
1.337 + if (TraceScavenge) {
1.338 + gclog_or_tty->print_cr("{%s %s 0x%x (%d)}",
1.339 + "promotion-failure",
1.340 + obj->klass()->internal_name(),
1.341 + (void *)obj, obj->size());
1.342 +
1.343 + }
1.344 +#endif
1.345 +
1.346 + return obj;
1.347 +}
