1 /* 2 * Copyright (c) 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 #include "precompiled.hpp" 25 26 #include "logging/log.hpp" 27 #include "logging/logStream.hpp" 28 #include "memory/metaspace/chunkManager.hpp" 29 #include "memory/metaspace/metachunk.hpp" 30 #include "memory/metaspace/metaDebug.hpp" 31 #include "memory/metaspace/metaspaceCommon.hpp" 32 #include "memory/metaspace/spaceManager.hpp" 33 #include "memory/metaspace/virtualSpaceList.hpp" 34 #include "runtime/atomic.hpp" 35 #include "runtime/init.hpp" 36 #include "services/memoryService.hpp" 37 #include "utilities/debug.hpp" 38 #include "utilities/globalDefinitions.hpp" 39 40 namespace metaspace { 41 namespace internals { 42 43 #define assert_counter(expected_value, real_value, msg) \ 44 assert( (expected_value) == (real_value), \ 45 "Counter mismatch (%s): expected " SIZE_FORMAT \ 46 ", but got: " SIZE_FORMAT ".", msg, expected_value, \ 47 real_value); 48 49 // SpaceManager methods 50 51 size_t SpaceManager::adjust_initial_chunk_size(size_t requested, bool is_class_space) { 52 size_t chunk_sizes[] = { 53 specialized_chunk_size(is_class_space), 54 small_chunk_size(is_class_space), 55 medium_chunk_size(is_class_space) 56 }; 57 58 // Adjust up to one of the fixed chunk sizes ... 59 for (size_t i = 0; i < ARRAY_SIZE(chunk_sizes); i++) { 60 if (requested <= chunk_sizes[i]) { 61 return chunk_sizes[i]; 62 } 63 } 64 65 // ... or return the size as a humongous chunk. 66 return requested; 67 } 68 69 size_t SpaceManager::adjust_initial_chunk_size(size_t requested) const { 70 return adjust_initial_chunk_size(requested, is_class()); 71 } 72 73 size_t SpaceManager::get_initial_chunk_size(Metaspace::MetaspaceType type) const { 74 size_t requested; 75 76 if (is_class()) { 77 switch (type) { 78 case Metaspace::BootMetaspaceType: requested = Metaspace::first_class_chunk_word_size(); break; 79 case Metaspace::AnonymousMetaspaceType: requested = ClassSpecializedChunk; break; 80 case Metaspace::ReflectionMetaspaceType: requested = ClassSpecializedChunk; break; 81 default: requested = ClassSmallChunk; break; 82 } 83 } else { 84 switch (type) { 85 case Metaspace::BootMetaspaceType: requested = Metaspace::first_chunk_word_size(); break; 86 case Metaspace::AnonymousMetaspaceType: requested = SpecializedChunk; break; 87 case Metaspace::ReflectionMetaspaceType: requested = SpecializedChunk; break; 88 default: requested = SmallChunk; break; 89 } 90 } 91 92 // Adjust to one of the fixed chunk sizes (unless humongous) 93 const size_t adjusted = adjust_initial_chunk_size(requested); 94 95 assert(adjusted != 0, "Incorrect initial chunk size. Requested: " 96 SIZE_FORMAT " adjusted: " SIZE_FORMAT, requested, adjusted); 97 98 return adjusted; 99 } 100 101 void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const { 102 103 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 104 st->print("SpaceManager: " UINTX_FORMAT " %s chunks.", 105 num_chunks_by_type(i), chunk_size_name(i)); 106 } 107 108 chunk_manager()->locked_print_free_chunks(st); 109 } 110 111 size_t SpaceManager::calc_chunk_size(size_t word_size) { 112 113 // Decide between a small chunk and a medium chunk. Up to 114 // _small_chunk_limit small chunks can be allocated. 115 // After that a medium chunk is preferred. 116 size_t chunk_word_size; 117 118 // Special case for anonymous metadata space. 119 // Anonymous metadata space is usually small, with majority within 1K - 2K range and 120 // rarely about 4K (64-bits JVM). 121 // Instead of jumping to SmallChunk after initial chunk exhausted, keeping allocation 122 // from SpecializeChunk up to _anon_or_delegating_metadata_specialize_chunk_limit (4) 123 // reduces space waste from 60+% to around 30%. 124 if ((_space_type == Metaspace::AnonymousMetaspaceType || _space_type == Metaspace::ReflectionMetaspaceType) && 125 _mdtype == Metaspace::NonClassType && 126 num_chunks_by_type(SpecializedIndex) < anon_and_delegating_metadata_specialize_chunk_limit && 127 word_size + Metachunk::overhead() <= SpecializedChunk) { 128 return SpecializedChunk; 129 } 130 131 if (num_chunks_by_type(MediumIndex) == 0 && 132 num_chunks_by_type(SmallIndex) < small_chunk_limit) { 133 chunk_word_size = (size_t) small_chunk_size(); 134 if (word_size + Metachunk::overhead() > small_chunk_size()) { 135 chunk_word_size = medium_chunk_size(); 136 } 137 } else { 138 chunk_word_size = medium_chunk_size(); 139 } 140 141 // Might still need a humongous chunk. Enforce 142 // humongous allocations sizes to be aligned up to 143 // the smallest chunk size. 144 size_t if_humongous_sized_chunk = 145 align_up(word_size + Metachunk::overhead(), 146 smallest_chunk_size()); 147 chunk_word_size = 148 MAX2((size_t) chunk_word_size, if_humongous_sized_chunk); 149 150 assert(!SpaceManager::is_humongous(word_size) || 151 chunk_word_size == if_humongous_sized_chunk, 152 "Size calculation is wrong, word_size " SIZE_FORMAT 153 " chunk_word_size " SIZE_FORMAT, 154 word_size, chunk_word_size); 155 Log(gc, metaspace, alloc) log; 156 if (log.is_debug() && SpaceManager::is_humongous(word_size)) { 157 log.debug("Metadata humongous allocation:"); 158 log.debug(" word_size " PTR_FORMAT, word_size); 159 log.debug(" chunk_word_size " PTR_FORMAT, chunk_word_size); 160 log.debug(" chunk overhead " PTR_FORMAT, Metachunk::overhead()); 161 } 162 return chunk_word_size; 163 } 164 165 void SpaceManager::track_metaspace_memory_usage() { 166 if (is_init_completed()) { 167 if (is_class()) { 168 MemoryService::track_compressed_class_memory_usage(); 169 } 170 MemoryService::track_metaspace_memory_usage(); 171 } 172 } 173 174 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) { 175 assert_lock_strong(_lock); 176 assert(vs_list()->current_virtual_space() != NULL, 177 "Should have been set"); 178 assert(current_chunk() == NULL || 179 current_chunk()->allocate(word_size) == NULL, 180 "Don't need to expand"); 181 MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag); 182 183 if (log_is_enabled(Trace, gc, metaspace, freelist)) { 184 size_t words_left = 0; 185 size_t words_used = 0; 186 if (current_chunk() != NULL) { 187 words_left = current_chunk()->free_word_size(); 188 words_used = current_chunk()->used_word_size(); 189 } 190 log_trace(gc, metaspace, freelist)("SpaceManager::grow_and_allocate for " SIZE_FORMAT " words " SIZE_FORMAT " words used " SIZE_FORMAT " words left", 191 word_size, words_used, words_left); 192 } 193 194 // Get another chunk 195 size_t chunk_word_size = calc_chunk_size(word_size); 196 Metachunk* next = get_new_chunk(chunk_word_size); 197 198 MetaWord* mem = NULL; 199 200 // If a chunk was available, add it to the in-use chunk list 201 // and do an allocation from it. 202 if (next != NULL) { 203 // Add to this manager's list of chunks in use. 204 // If the new chunk is humongous, it was created to serve a single large allocation. In that 205 // case it usually makes no sense to make it the current chunk, since the next allocation would 206 // need to allocate a new chunk anyway, while we would now prematurely retire a perfectly 207 // good chunk which could be used for more normal allocations. 208 bool make_current = true; 209 if (next->get_chunk_type() == HumongousIndex && 210 current_chunk() != NULL) { 211 make_current = false; 212 } 213 add_chunk(next, make_current); 214 mem = next->allocate(word_size); 215 } 216 217 // Track metaspace memory usage statistic. 218 track_metaspace_memory_usage(); 219 220 return mem; 221 } 222 223 void SpaceManager::print_on(outputStream* st) const { 224 SpaceManagerStatistics stat; 225 add_to_statistics(&stat); // will lock _lock. 226 stat.print_on(st, 1*K, false); 227 } 228 229 SpaceManager::SpaceManager(Metaspace::MetadataType mdtype, 230 Metaspace::MetaspaceType space_type,// 231 Mutex* lock) : 232 _mdtype(mdtype), 233 _space_type(space_type), 234 _capacity_words(0), 235 _used_words(0), 236 _overhead_words(0), 237 _block_freelists(NULL), 238 _lock(lock), 239 _chunk_list(NULL), 240 _current_chunk(NULL) 241 { 242 Metadebug::init_allocation_fail_alot_count(); 243 memset(_num_chunks_by_type, 0, sizeof(_num_chunks_by_type)); 244 log_trace(gc, metaspace, freelist)("SpaceManager(): " PTR_FORMAT, p2i(this)); 245 } 246 247 void SpaceManager::account_for_new_chunk(const Metachunk* new_chunk) { 248 249 assert_lock_strong(MetaspaceExpand_lock); 250 251 _capacity_words += new_chunk->word_size(); 252 _overhead_words += Metachunk::overhead(); 253 DEBUG_ONLY(new_chunk->verify()); 254 _num_chunks_by_type[new_chunk->get_chunk_type()] ++; 255 256 // Adjust global counters: 257 MetaspaceUtils::inc_capacity(mdtype(), new_chunk->word_size()); 258 MetaspaceUtils::inc_overhead(mdtype(), Metachunk::overhead()); 259 } 260 261 void SpaceManager::account_for_allocation(size_t words) { 262 // Note: we should be locked with the ClassloaderData-specific metaspace lock. 263 // We may or may not be locked with the global metaspace expansion lock. 264 assert_lock_strong(lock()); 265 266 // Add to the per SpaceManager totals. This can be done non-atomically. 267 _used_words += words; 268 269 // Adjust global counters. This will be done atomically. 270 MetaspaceUtils::inc_used(mdtype(), words); 271 } 272 273 void SpaceManager::account_for_spacemanager_death() { 274 275 assert_lock_strong(MetaspaceExpand_lock); 276 277 MetaspaceUtils::dec_capacity(mdtype(), _capacity_words); 278 MetaspaceUtils::dec_overhead(mdtype(), _overhead_words); 279 MetaspaceUtils::dec_used(mdtype(), _used_words); 280 } 281 282 SpaceManager::~SpaceManager() { 283 284 // This call this->_lock which can't be done while holding MetaspaceExpand_lock 285 DEBUG_ONLY(verify_metrics()); 286 287 MutexLockerEx fcl(MetaspaceExpand_lock, 288 Mutex::_no_safepoint_check_flag); 289 290 chunk_manager()->slow_locked_verify(); 291 292 account_for_spacemanager_death(); 293 294 Log(gc, metaspace, freelist) log; 295 if (log.is_trace()) { 296 log.trace("~SpaceManager(): " PTR_FORMAT, p2i(this)); 297 ResourceMark rm; 298 LogStream ls(log.trace()); 299 locked_print_chunks_in_use_on(&ls); 300 if (block_freelists() != NULL) { 301 block_freelists()->print_on(&ls); 302 } 303 } 304 305 // Add all the chunks in use by this space manager 306 // to the global list of free chunks. 307 308 // Follow each list of chunks-in-use and add them to the 309 // free lists. Each list is NULL terminated. 310 chunk_manager()->return_chunk_list(chunk_list()); 311 #ifdef ASSERT 312 _chunk_list = NULL; 313 _current_chunk = NULL; 314 #endif 315 316 chunk_manager()->slow_locked_verify(); 317 318 if (_block_freelists != NULL) { 319 delete _block_freelists; 320 } 321 } 322 323 void SpaceManager::deallocate(MetaWord* p, size_t word_size) { 324 assert_lock_strong(lock()); 325 // Allocations and deallocations are in raw_word_size 326 size_t raw_word_size = get_allocation_word_size(word_size); 327 // Lazily create a block_freelist 328 if (block_freelists() == NULL) { 329 _block_freelists = new BlockFreelist(); 330 } 331 block_freelists()->return_block(p, raw_word_size); 332 DEBUG_ONLY(Atomic::inc(&(g_internal_statistics.num_deallocs))); 333 } 334 335 // Adds a chunk to the list of chunks in use. 336 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) { 337 338 assert_lock_strong(_lock); 339 assert(new_chunk != NULL, "Should not be NULL"); 340 assert(new_chunk->next() == NULL, "Should not be on a list"); 341 342 new_chunk->reset_empty(); 343 344 // Find the correct list and and set the current 345 // chunk for that list. 346 ChunkIndex index = chunk_manager()->list_index(new_chunk->word_size()); 347 348 if (make_current) { 349 // If we are to make the chunk current, retire the old current chunk and replace 350 // it with the new chunk. 351 retire_current_chunk(); 352 set_current_chunk(new_chunk); 353 } 354 355 // Add the new chunk at the head of its respective chunk list. 356 new_chunk->set_next(_chunk_list); 357 _chunk_list = new_chunk; 358 359 // Adjust counters. 360 account_for_new_chunk(new_chunk); 361 362 assert(new_chunk->is_empty(), "Not ready for reuse"); 363 Log(gc, metaspace, freelist) log; 364 if (log.is_trace()) { 365 log.trace("SpaceManager::added chunk: "); 366 ResourceMark rm; 367 LogStream ls(log.trace()); 368 new_chunk->print_on(&ls); 369 chunk_manager()->locked_print_free_chunks(&ls); 370 } 371 } 372 373 void SpaceManager::retire_current_chunk() { 374 if (current_chunk() != NULL) { 375 size_t remaining_words = current_chunk()->free_word_size(); 376 if (remaining_words >= SmallBlocks::small_block_min_size()) { 377 MetaWord* ptr = current_chunk()->allocate(remaining_words); 378 deallocate(ptr, remaining_words); 379 account_for_allocation(remaining_words); 380 } 381 } 382 } 383 384 Metachunk* SpaceManager::get_new_chunk(size_t chunk_word_size) { 385 // Get a chunk from the chunk freelist 386 Metachunk* next = chunk_manager()->chunk_freelist_allocate(chunk_word_size); 387 388 if (next == NULL) { 389 next = vs_list()->get_new_chunk(chunk_word_size, 390 medium_chunk_bunch()); 391 } 392 393 Log(gc, metaspace, alloc) log; 394 if (log.is_debug() && next != NULL && 395 SpaceManager::is_humongous(next->word_size())) { 396 log.debug(" new humongous chunk word size " PTR_FORMAT, next->word_size()); 397 } 398 399 return next; 400 } 401 402 MetaWord* SpaceManager::allocate(size_t word_size) { 403 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 404 size_t raw_word_size = get_allocation_word_size(word_size); 405 BlockFreelist* fl = block_freelists(); 406 MetaWord* p = NULL; 407 408 DEBUG_ONLY(if (VerifyMetaspace) verify_metrics_locked()); 409 410 // Allocation from the dictionary is expensive in the sense that 411 // the dictionary has to be searched for a size. Don't allocate 412 // from the dictionary until it starts to get fat. Is this 413 // a reasonable policy? Maybe an skinny dictionary is fast enough 414 // for allocations. Do some profiling. JJJ 415 if (fl != NULL && fl->total_size() > allocation_from_dictionary_limit) { 416 p = fl->get_block(raw_word_size); 417 if (p != NULL) { 418 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_allocs_from_deallocated_blocks)); 419 } 420 } 421 if (p == NULL) { 422 p = allocate_work(raw_word_size); 423 } 424 425 return p; 426 } 427 428 // Returns the address of spaced allocated for "word_size". 429 // This methods does not know about blocks (Metablocks) 430 MetaWord* SpaceManager::allocate_work(size_t word_size) { 431 assert_lock_strong(lock()); 432 #ifdef ASSERT 433 if (Metadebug::test_metadata_failure()) { 434 return NULL; 435 } 436 #endif 437 // Is there space in the current chunk? 438 MetaWord* result = NULL; 439 440 if (current_chunk() != NULL) { 441 result = current_chunk()->allocate(word_size); 442 } 443 444 if (result == NULL) { 445 result = grow_and_allocate(word_size); 446 } 447 448 if (result != NULL) { 449 account_for_allocation(word_size); 450 } 451 452 return result; 453 } 454 455 void SpaceManager::verify() { 456 Metachunk* curr = chunk_list(); 457 while (curr != NULL) { 458 DEBUG_ONLY(do_verify_chunk(curr);) 459 assert(curr->is_tagged_free() == false, "Chunk should be tagged as in use."); 460 curr = curr->next(); 461 } 462 } 463 464 void SpaceManager::verify_chunk_size(Metachunk* chunk) { 465 assert(is_humongous(chunk->word_size()) || 466 chunk->word_size() == medium_chunk_size() || 467 chunk->word_size() == small_chunk_size() || 468 chunk->word_size() == specialized_chunk_size(), 469 "Chunk size is wrong"); 470 return; 471 } 472 473 void SpaceManager::add_to_statistics_locked(SpaceManagerStatistics* out) const { 474 assert_lock_strong(lock()); 475 Metachunk* chunk = chunk_list(); 476 while (chunk != NULL) { 477 UsedChunksStatistics& chunk_stat = out->chunk_stats(chunk->get_chunk_type()); 478 chunk_stat.add_num(1); 479 chunk_stat.add_cap(chunk->word_size()); 480 chunk_stat.add_overhead(Metachunk::overhead()); 481 chunk_stat.add_used(chunk->used_word_size() - Metachunk::overhead()); 482 if (chunk != current_chunk()) { 483 chunk_stat.add_waste(chunk->free_word_size()); 484 } else { 485 chunk_stat.add_free(chunk->free_word_size()); 486 } 487 chunk = chunk->next(); 488 } 489 if (block_freelists() != NULL) { 490 out->add_free_blocks_info(block_freelists()->num_blocks(), block_freelists()->total_size()); 491 } 492 } 493 494 void SpaceManager::add_to_statistics(SpaceManagerStatistics* out) const { 495 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 496 add_to_statistics_locked(out); 497 } 498 499 #ifdef ASSERT 500 void SpaceManager::verify_metrics_locked() const { 501 assert_lock_strong(lock()); 502 503 SpaceManagerStatistics stat; 504 add_to_statistics_locked(&stat); 505 506 UsedChunksStatistics chunk_stats = stat.totals(); 507 508 DEBUG_ONLY(chunk_stats.check_sanity()); 509 510 assert_counter(_capacity_words, chunk_stats.cap(), "SpaceManager::_capacity_words"); 511 assert_counter(_used_words, chunk_stats.used(), "SpaceManager::_used_words"); 512 assert_counter(_overhead_words, chunk_stats.overhead(), "SpaceManager::_overhead_words"); 513 } 514 515 void SpaceManager::verify_metrics() const { 516 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 517 verify_metrics_locked(); 518 } 519 #endif // ASSERT 520 521 522 } // namespace metaspace 523 } // namespace internals