1 /* 2 * Copyright (c) 2002, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/javaClasses.inline.hpp" 27 #include "gc/parallel/gcTaskManager.hpp" 28 #include "gc/parallel/mutableSpace.hpp" 29 #include "gc/parallel/parallelScavengeHeap.hpp" 30 #include "gc/parallel/psOldGen.hpp" 31 #include "gc/parallel/psPromotionManager.inline.hpp" 32 #include "gc/parallel/psScavenge.inline.hpp" 33 #include "gc/shared/gcTrace.hpp" 34 #include "gc/shared/preservedMarks.inline.hpp" 35 #include "gc/shared/taskqueue.inline.hpp" 36 #include "logging/log.hpp" 37 #include "logging/logStream.hpp" 38 #include "memory/allocation.inline.hpp" 39 #include "memory/iterator.inline.hpp" 40 #include "memory/memRegion.hpp" 41 #include "memory/padded.inline.hpp" 42 #include "memory/resourceArea.hpp" 43 #include "oops/access.inline.hpp" 44 #include "oops/compressedOops.inline.hpp" 45 #include "oops/valueArrayKlass.inline.hpp" 46 47 PaddedEnd<PSPromotionManager>* PSPromotionManager::_manager_array = NULL; 48 OopStarTaskQueueSet* PSPromotionManager::_stack_array_depth = NULL; 49 PreservedMarksSet* PSPromotionManager::_preserved_marks_set = NULL; 50 PSOldGen* PSPromotionManager::_old_gen = NULL; 51 MutableSpace* PSPromotionManager::_young_space = NULL; 52 53 void PSPromotionManager::initialize() { 54 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 55 56 _old_gen = heap->old_gen(); 57 _young_space = heap->young_gen()->to_space(); 58 59 const uint promotion_manager_num = ParallelGCThreads + 1; 60 61 // To prevent false sharing, we pad the PSPromotionManagers 62 // and make sure that the first instance starts at a cache line. 63 assert(_manager_array == NULL, "Attempt to initialize twice"); 64 _manager_array = PaddedArray<PSPromotionManager, mtGC>::create_unfreeable(promotion_manager_num); 65 guarantee(_manager_array != NULL, "Could not initialize promotion manager"); 66 67 _stack_array_depth = new OopStarTaskQueueSet(ParallelGCThreads); 68 guarantee(_stack_array_depth != NULL, "Could not initialize promotion manager"); 69 70 // Create and register the PSPromotionManager(s) for the worker threads. 71 for(uint i=0; i<ParallelGCThreads; i++) { 72 stack_array_depth()->register_queue(i, _manager_array[i].claimed_stack_depth()); 73 } 74 // The VMThread gets its own PSPromotionManager, which is not available 75 // for work stealing. 76 77 assert(_preserved_marks_set == NULL, "Attempt to initialize twice"); 78 _preserved_marks_set = new PreservedMarksSet(true /* in_c_heap */); 79 guarantee(_preserved_marks_set != NULL, "Could not initialize preserved marks set"); 80 _preserved_marks_set->init(promotion_manager_num); 81 for (uint i = 0; i < promotion_manager_num; i += 1) { 82 _manager_array[i].register_preserved_marks(_preserved_marks_set->get(i)); 83 } 84 } 85 86 // Helper functions to get around the circular dependency between 87 // psScavenge.inline.hpp and psPromotionManager.inline.hpp. 88 bool PSPromotionManager::should_scavenge(oop* p, bool check_to_space) { 89 return PSScavenge::should_scavenge(p, check_to_space); 90 } 91 bool PSPromotionManager::should_scavenge(narrowOop* p, bool check_to_space) { 92 return PSScavenge::should_scavenge(p, check_to_space); 93 } 94 95 PSPromotionManager* PSPromotionManager::gc_thread_promotion_manager(uint index) { 96 assert(index < ParallelGCThreads, "index out of range"); 97 assert(_manager_array != NULL, "Sanity"); 98 return &_manager_array[index]; 99 } 100 101 PSPromotionManager* PSPromotionManager::vm_thread_promotion_manager() { 102 assert(_manager_array != NULL, "Sanity"); 103 return &_manager_array[ParallelGCThreads]; 104 } 105 106 void PSPromotionManager::pre_scavenge() { 107 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 108 109 _preserved_marks_set->assert_empty(); 110 _young_space = heap->young_gen()->to_space(); 111 112 for(uint i=0; i<ParallelGCThreads+1; i++) { 113 manager_array(i)->reset(); 114 } 115 } 116 117 bool PSPromotionManager::post_scavenge(YoungGCTracer& gc_tracer) { 118 bool promotion_failure_occurred = false; 119 120 TASKQUEUE_STATS_ONLY(print_taskqueue_stats()); 121 for (uint i = 0; i < ParallelGCThreads + 1; i++) { 122 PSPromotionManager* manager = manager_array(i); 123 assert(manager->claimed_stack_depth()->is_empty(), "should be empty"); 124 if (manager->_promotion_failed_info.has_failed()) { 125 gc_tracer.report_promotion_failed(manager->_promotion_failed_info); 126 promotion_failure_occurred = true; 127 } 128 manager->flush_labs(); 129 } 130 if (!promotion_failure_occurred) { 131 // If there was no promotion failure, the preserved mark stacks 132 // should be empty. 133 _preserved_marks_set->assert_empty(); 134 } 135 return promotion_failure_occurred; 136 } 137 138 #if TASKQUEUE_STATS 139 void 140 PSPromotionManager::print_local_stats(outputStream* const out, uint i) const { 141 #define FMT " " SIZE_FORMAT_W(10) 142 out->print_cr("%3u" FMT FMT FMT FMT, i, _masked_pushes, _masked_steals, 143 _arrays_chunked, _array_chunks_processed); 144 #undef FMT 145 } 146 147 static const char* const pm_stats_hdr[] = { 148 " --------masked------- arrays array", 149 "thr push steal chunked chunks", 150 "--- ---------- ---------- ---------- ----------" 151 }; 152 153 void 154 PSPromotionManager::print_taskqueue_stats() { 155 if (!log_is_enabled(Trace, gc, task, stats)) { 156 return; 157 } 158 Log(gc, task, stats) log; 159 ResourceMark rm; 160 LogStream ls(log.trace()); 161 outputStream* out = &ls; 162 out->print_cr("== GC Tasks Stats, GC %3d", 163 ParallelScavengeHeap::heap()->total_collections()); 164 165 TaskQueueStats totals; 166 out->print("thr "); TaskQueueStats::print_header(1, out); out->cr(); 167 out->print("--- "); TaskQueueStats::print_header(2, out); out->cr(); 168 for (uint i = 0; i < ParallelGCThreads + 1; ++i) { 169 TaskQueueStats& next = manager_array(i)->_claimed_stack_depth.stats; 170 out->print("%3d ", i); next.print(out); out->cr(); 171 totals += next; 172 } 173 out->print("tot "); totals.print(out); out->cr(); 174 175 const uint hlines = sizeof(pm_stats_hdr) / sizeof(pm_stats_hdr[0]); 176 for (uint i = 0; i < hlines; ++i) out->print_cr("%s", pm_stats_hdr[i]); 177 for (uint i = 0; i < ParallelGCThreads + 1; ++i) { 178 manager_array(i)->print_local_stats(out, i); 179 } 180 } 181 182 void 183 PSPromotionManager::reset_stats() { 184 claimed_stack_depth()->stats.reset(); 185 _masked_pushes = _masked_steals = 0; 186 _arrays_chunked = _array_chunks_processed = 0; 187 } 188 #endif // TASKQUEUE_STATS 189 190 PSPromotionManager::PSPromotionManager() { 191 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 192 193 // We set the old lab's start array. 194 _old_lab.set_start_array(old_gen()->start_array()); 195 196 uint queue_size; 197 claimed_stack_depth()->initialize(); 198 queue_size = claimed_stack_depth()->max_elems(); 199 200 _totally_drain = (ParallelGCThreads == 1) || (GCDrainStackTargetSize == 0); 201 if (_totally_drain) { 202 _target_stack_size = 0; 203 } else { 204 // don't let the target stack size to be more than 1/4 of the entries 205 _target_stack_size = (uint) MIN2((uint) GCDrainStackTargetSize, 206 (uint) (queue_size / 4)); 207 } 208 209 _array_chunk_size = ParGCArrayScanChunk; 210 // let's choose 1.5x the chunk size 211 _min_array_size_for_chunking = 3 * _array_chunk_size / 2; 212 213 _preserved_marks = NULL; 214 215 reset(); 216 } 217 218 void PSPromotionManager::reset() { 219 assert(stacks_empty(), "reset of non-empty stack"); 220 221 // We need to get an assert in here to make sure the labs are always flushed. 222 223 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 224 225 // Do not prefill the LAB's, save heap wastage! 226 HeapWord* lab_base = young_space()->top(); 227 _young_lab.initialize(MemRegion(lab_base, (size_t)0)); 228 _young_gen_is_full = false; 229 230 lab_base = old_gen()->object_space()->top(); 231 _old_lab.initialize(MemRegion(lab_base, (size_t)0)); 232 _old_gen_is_full = false; 233 234 _promotion_failed_info.reset(); 235 236 TASKQUEUE_STATS_ONLY(reset_stats()); 237 } 238 239 void PSPromotionManager::register_preserved_marks(PreservedMarks* preserved_marks) { 240 assert(_preserved_marks == NULL, "do not set it twice"); 241 _preserved_marks = preserved_marks; 242 } 243 244 class ParRestoreGCTask : public GCTask { 245 private: 246 const uint _id; 247 PreservedMarksSet* const _preserved_marks_set; 248 volatile size_t* const _total_size_addr; 249 250 public: 251 virtual char* name() { 252 return (char*) "preserved mark restoration task"; 253 } 254 255 virtual void do_it(GCTaskManager* manager, uint which){ 256 _preserved_marks_set->get(_id)->restore_and_increment(_total_size_addr); 257 } 258 259 ParRestoreGCTask(uint id, 260 PreservedMarksSet* preserved_marks_set, 261 volatile size_t* total_size_addr) 262 : _id(id), 263 _preserved_marks_set(preserved_marks_set), 264 _total_size_addr(total_size_addr) { } 265 }; 266 267 class PSRestorePreservedMarksTaskExecutor : public RestorePreservedMarksTaskExecutor { 268 private: 269 GCTaskManager* _gc_task_manager; 270 271 public: 272 PSRestorePreservedMarksTaskExecutor(GCTaskManager* gc_task_manager) 273 : _gc_task_manager(gc_task_manager) { } 274 275 void restore(PreservedMarksSet* preserved_marks_set, 276 volatile size_t* total_size_addr) { 277 // GCTask / GCTaskQueue are ResourceObjs 278 ResourceMark rm; 279 280 GCTaskQueue* q = GCTaskQueue::create(); 281 for (uint i = 0; i < preserved_marks_set->num(); i += 1) { 282 q->enqueue(new ParRestoreGCTask(i, preserved_marks_set, total_size_addr)); 283 } 284 _gc_task_manager->execute_and_wait(q); 285 } 286 }; 287 288 void PSPromotionManager::restore_preserved_marks() { 289 PSRestorePreservedMarksTaskExecutor task_executor(PSScavenge::gc_task_manager()); 290 _preserved_marks_set->restore(&task_executor); 291 } 292 293 void PSPromotionManager::drain_stacks_depth(bool totally_drain) { 294 totally_drain = totally_drain || _totally_drain; 295 296 #ifdef ASSERT 297 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 298 MutableSpace* to_space = heap->young_gen()->to_space(); 299 MutableSpace* old_space = heap->old_gen()->object_space(); 300 #endif /* ASSERT */ 301 302 OopStarTaskQueue* const tq = claimed_stack_depth(); 303 do { 304 StarTask p; 305 306 // Drain overflow stack first, so other threads can steal from 307 // claimed stack while we work. 308 while (tq->pop_overflow(p)) { 309 process_popped_location_depth(p); 310 } 311 312 if (totally_drain) { 313 while (tq->pop_local(p)) { 314 process_popped_location_depth(p); 315 } 316 } else { 317 while (tq->size() > _target_stack_size && tq->pop_local(p)) { 318 process_popped_location_depth(p); 319 } 320 } 321 } while ((totally_drain && !tq->taskqueue_empty()) || !tq->overflow_empty()); 322 323 assert(!totally_drain || tq->taskqueue_empty(), "Sanity"); 324 assert(totally_drain || tq->size() <= _target_stack_size, "Sanity"); 325 assert(tq->overflow_empty(), "Sanity"); 326 } 327 328 void PSPromotionManager::flush_labs() { 329 assert(stacks_empty(), "Attempt to flush lab with live stack"); 330 331 // If either promotion lab fills up, we can flush the 332 // lab but not refill it, so check first. 333 assert(!_young_lab.is_flushed() || _young_gen_is_full, "Sanity"); 334 if (!_young_lab.is_flushed()) 335 _young_lab.flush(); 336 337 assert(!_old_lab.is_flushed() || _old_gen_is_full, "Sanity"); 338 if (!_old_lab.is_flushed()) 339 _old_lab.flush(); 340 341 // Let PSScavenge know if we overflowed 342 if (_young_gen_is_full) { 343 PSScavenge::set_survivor_overflow(true); 344 } 345 } 346 347 template <class T> void PSPromotionManager::process_array_chunk_work( 348 oop obj, 349 int start, int end) { 350 assert(start <= end, "invariant"); 351 T* const base = (T*)objArrayOop(obj)->base(); 352 T* p = base + start; 353 T* const chunk_end = base + end; 354 while (p < chunk_end) { 355 if (PSScavenge::should_scavenge(p)) { 356 claim_or_forward_depth(p); 357 } 358 ++p; 359 } 360 } 361 362 void PSPromotionManager::process_array_chunk(oop old) { 363 assert(PSChunkLargeArrays, "invariant"); 364 assert(old->is_objArray(), "invariant"); 365 assert(old->is_forwarded(), "invariant"); 366 367 TASKQUEUE_STATS_ONLY(++_array_chunks_processed); 368 369 oop const obj = old->forwardee(); 370 371 int start; 372 int const end = arrayOop(old)->length(); 373 if (end > (int) _min_array_size_for_chunking) { 374 // we'll chunk more 375 start = end - _array_chunk_size; 376 assert(start > 0, "invariant"); 377 arrayOop(old)->set_length(start); 378 push_depth(mask_chunked_array_oop(old)); 379 TASKQUEUE_STATS_ONLY(++_masked_pushes); 380 } else { 381 // this is the final chunk for this array 382 start = 0; 383 int const actual_length = arrayOop(obj)->length(); 384 arrayOop(old)->set_length(actual_length); 385 } 386 387 if (UseCompressedOops) { 388 process_array_chunk_work<narrowOop>(obj, start, end); 389 } else { 390 process_array_chunk_work<oop>(obj, start, end); 391 } 392 } 393 394 oop PSPromotionManager::oop_promotion_failed(oop obj, markOop obj_mark) { 395 assert(_old_gen_is_full || PromotionFailureALot, "Sanity"); 396 397 // Attempt to CAS in the header. 398 // This tests if the header is still the same as when 399 // this started. If it is the same (i.e., no forwarding 400 // pointer has been installed), then this thread owns 401 // it. 402 if (obj->cas_forward_to(obj, obj_mark)) { 403 // We won any races, we "own" this object. 404 assert(obj == obj->forwardee(), "Sanity"); 405 406 _promotion_failed_info.register_copy_failure(obj->size()); 407 408 push_contents(obj); 409 410 _preserved_marks->push_if_necessary(obj, obj_mark); 411 } else { 412 // We lost, someone else "owns" this object 413 guarantee(obj->is_forwarded(), "Object must be forwarded if the cas failed."); 414 415 // No unallocation to worry about. 416 obj = obj->forwardee(); 417 } 418 419 log_develop_trace(gc, scavenge)("{promotion-failure %s " PTR_FORMAT " (%d)}", obj->klass()->internal_name(), p2i(obj), obj->size()); 420 421 return obj; 422 }