1 /* 2 * Copyright (c) 2011, 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 #include "aot/aotLoader.hpp" 26 #include "gc/shared/collectedHeap.hpp" 27 #include "gc/shared/collectorPolicy.hpp" 28 #include "logging/log.hpp" 29 #include "logging/logStream.hpp" 30 #include "memory/allocation.hpp" 31 #include "memory/binaryTreeDictionary.inline.hpp" 32 #include "memory/filemap.hpp" 33 #include "memory/freeList.inline.hpp" 34 #include "memory/metachunk.hpp" 35 #include "memory/metaspace.hpp" 36 #include "memory/metaspace/metaspaceCommon.hpp" 37 #include "memory/metaspace/metaspaceStatistics.hpp" 38 #include "memory/metaspaceGCThresholdUpdater.hpp" 39 #include "memory/metaspaceShared.hpp" 40 #include "memory/metaspaceTracer.hpp" 41 #include "memory/resourceArea.hpp" 42 #include "memory/universe.hpp" 43 #include "runtime/atomic.hpp" 44 #include "runtime/globals.hpp" 45 #include "runtime/init.hpp" 46 #include "runtime/java.hpp" 47 #include "runtime/mutex.hpp" 48 #include "runtime/mutexLocker.hpp" 49 #include "runtime/orderAccess.inline.hpp" 50 #include "services/memTracker.hpp" 51 #include "services/memoryService.hpp" 52 #include "utilities/align.hpp" 53 #include "utilities/copy.hpp" 54 #include "utilities/debug.hpp" 55 #include "utilities/macros.hpp" 56 57 using namespace metaspace::internals; 58 59 typedef BinaryTreeDictionary<Metablock, FreeList<Metablock> > BlockTreeDictionary; 60 typedef BinaryTreeDictionary<Metachunk, FreeList<Metachunk> > ChunkTreeDictionary; 61 62 // Helper function that does a bunch of checks for a chunk. 63 DEBUG_ONLY(static void do_verify_chunk(Metachunk* chunk);) 64 65 // Given a Metachunk, update its in-use information (both in the 66 // chunk and the occupancy map). 67 static void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse); 68 69 size_t const allocation_from_dictionary_limit = 4 * K; 70 71 MetaWord* last_allocated = 0; 72 73 size_t Metaspace::_compressed_class_space_size; 74 const MetaspaceTracer* Metaspace::_tracer = NULL; 75 76 DEBUG_ONLY(bool Metaspace::_frozen = false;) 77 78 // Internal statistics. 79 #ifdef ASSERT 80 static struct { 81 // Number of allocations. 82 uintx num_allocs; 83 // Number of times a ClassLoaderMetaspace was born... 84 uintx num_metaspace_births; 85 // ... and died. 86 uintx num_metaspace_deaths; 87 // Number of times VirtualSpaceListNodes were created... 88 uintx num_vsnodes_created; 89 // ... and purged. 90 uintx num_vsnodes_purged; 91 // Number of times we expanded the committed section of the space. 92 uintx num_committed_space_expanded; 93 // Number of deallocations 94 uintx num_deallocs; 95 // Number of deallocations triggered from outside ("real" deallocations). 96 uintx num_external_deallocs; 97 // Number of times an allocation was satisfied from deallocated blocks. 98 uintx num_allocs_from_deallocated_blocks; 99 } g_internal_statistics; 100 #endif 101 102 enum ChunkSizes { // in words. 103 ClassSpecializedChunk = 128, 104 SpecializedChunk = 128, 105 ClassSmallChunk = 256, 106 SmallChunk = 512, 107 ClassMediumChunk = 4 * K, 108 MediumChunk = 8 * K 109 }; 110 111 // Returns size of this chunk type. 112 size_t get_size_for_nonhumongous_chunktype(ChunkIndex chunktype, bool is_class) { 113 assert(is_valid_nonhumongous_chunktype(chunktype), "invalid chunk type."); 114 size_t size = 0; 115 if (is_class) { 116 switch(chunktype) { 117 case SpecializedIndex: size = ClassSpecializedChunk; break; 118 case SmallIndex: size = ClassSmallChunk; break; 119 case MediumIndex: size = ClassMediumChunk; break; 120 default: 121 ShouldNotReachHere(); 122 } 123 } else { 124 switch(chunktype) { 125 case SpecializedIndex: size = SpecializedChunk; break; 126 case SmallIndex: size = SmallChunk; break; 127 case MediumIndex: size = MediumChunk; break; 128 default: 129 ShouldNotReachHere(); 130 } 131 } 132 return size; 133 } 134 135 ChunkIndex get_chunk_type_by_size(size_t size, bool is_class) { 136 if (is_class) { 137 if (size == ClassSpecializedChunk) { 138 return SpecializedIndex; 139 } else if (size == ClassSmallChunk) { 140 return SmallIndex; 141 } else if (size == ClassMediumChunk) { 142 return MediumIndex; 143 } else if (size > ClassMediumChunk) { 144 // A valid humongous chunk size is a multiple of the smallest chunk size. 145 assert(is_aligned(size, ClassSpecializedChunk), "Invalid chunk size"); 146 return HumongousIndex; 147 } 148 } else { 149 if (size == SpecializedChunk) { 150 return SpecializedIndex; 151 } else if (size == SmallChunk) { 152 return SmallIndex; 153 } else if (size == MediumChunk) { 154 return MediumIndex; 155 } else if (size > MediumChunk) { 156 // A valid humongous chunk size is a multiple of the smallest chunk size. 157 assert(is_aligned(size, SpecializedChunk), "Invalid chunk size"); 158 return HumongousIndex; 159 } 160 } 161 ShouldNotReachHere(); 162 return (ChunkIndex)-1; 163 } 164 165 ChunkIndex next_chunk_index(ChunkIndex i) { 166 assert(i < NumberOfInUseLists, "Out of bound"); 167 return (ChunkIndex) (i+1); 168 } 169 170 ChunkIndex prev_chunk_index(ChunkIndex i) { 171 assert(i > ZeroIndex, "Out of bound"); 172 return (ChunkIndex) (i-1); 173 } 174 175 static const char* space_type_name(Metaspace::MetaspaceType t) { 176 const char* s = NULL; 177 switch (t) { 178 case Metaspace::StandardMetaspaceType: s = "Standard"; break; 179 case Metaspace::BootMetaspaceType: s = "Boot"; break; 180 case Metaspace::AnonymousMetaspaceType: s = "Anonymous"; break; 181 case Metaspace::ReflectionMetaspaceType: s = "Reflection"; break; 182 default: ShouldNotReachHere(); 183 } 184 assert(s != NULL, "Invalid space type"); 185 return s; 186 } 187 188 volatile intptr_t MetaspaceGC::_capacity_until_GC = 0; 189 uint MetaspaceGC::_shrink_factor = 0; 190 bool MetaspaceGC::_should_concurrent_collect = false; 191 192 193 typedef class FreeList<Metachunk> ChunkList; 194 195 // Manages the global free lists of chunks. 196 class ChunkManager : public CHeapObj<mtInternal> { 197 friend class TestVirtualSpaceNodeTest; 198 199 // Free list of chunks of different sizes. 200 // SpecializedChunk 201 // SmallChunk 202 // MediumChunk 203 ChunkList _free_chunks[NumberOfFreeLists]; 204 205 // Whether or not this is the class chunkmanager. 206 const bool _is_class; 207 208 // Return non-humongous chunk list by its index. 209 ChunkList* free_chunks(ChunkIndex index); 210 211 // Returns non-humongous chunk list for the given chunk word size. 212 ChunkList* find_free_chunks_list(size_t word_size); 213 214 // HumongousChunk 215 ChunkTreeDictionary _humongous_dictionary; 216 217 // Returns the humongous chunk dictionary. 218 ChunkTreeDictionary* humongous_dictionary() { 219 return &_humongous_dictionary; 220 } 221 222 // Size, in metaspace words, of all chunks managed by this ChunkManager 223 size_t _free_chunks_total; 224 // Number of chunks in this ChunkManager 225 size_t _free_chunks_count; 226 227 // Update counters after a chunk was added or removed removed. 228 void account_for_added_chunk(const Metachunk* c); 229 void account_for_removed_chunk(const Metachunk* c); 230 231 // Debug support 232 233 size_t sum_free_chunks(); 234 size_t sum_free_chunks_count(); 235 236 void locked_verify_free_chunks_total(); 237 void slow_locked_verify_free_chunks_total() { 238 if (VerifyMetaspace) { 239 locked_verify_free_chunks_total(); 240 } 241 } 242 void locked_verify_free_chunks_count(); 243 void slow_locked_verify_free_chunks_count() { 244 if (VerifyMetaspace) { 245 locked_verify_free_chunks_count(); 246 } 247 } 248 void verify_free_chunks_count(); 249 250 // Given a pointer to a chunk, attempts to merge it with neighboring 251 // free chunks to form a bigger chunk. Returns true if successful. 252 bool attempt_to_coalesce_around_chunk(Metachunk* chunk, ChunkIndex target_chunk_type); 253 254 // Helper for chunk merging: 255 // Given an address range with 1-n chunks which are all supposed to be 256 // free and hence currently managed by this ChunkManager, remove them 257 // from this ChunkManager and mark them as invalid. 258 // - This does not correct the occupancy map. 259 // - This does not adjust the counters in ChunkManager. 260 // - Does not adjust container count counter in containing VirtualSpaceNode. 261 // Returns number of chunks removed. 262 int remove_chunks_in_area(MetaWord* p, size_t word_size); 263 264 // Helper for chunk splitting: given a target chunk size and a larger free chunk, 265 // split up the larger chunk into n smaller chunks, at least one of which should be 266 // the target chunk of target chunk size. The smaller chunks, including the target 267 // chunk, are returned to the freelist. The pointer to the target chunk is returned. 268 // Note that this chunk is supposed to be removed from the freelist right away. 269 Metachunk* split_chunk(size_t target_chunk_word_size, Metachunk* chunk); 270 271 public: 272 273 ChunkManager(bool is_class) 274 : _is_class(is_class), _free_chunks_total(0), _free_chunks_count(0) { 275 _free_chunks[SpecializedIndex].set_size(get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class)); 276 _free_chunks[SmallIndex].set_size(get_size_for_nonhumongous_chunktype(SmallIndex, is_class)); 277 _free_chunks[MediumIndex].set_size(get_size_for_nonhumongous_chunktype(MediumIndex, is_class)); 278 } 279 280 // Add or delete (return) a chunk to the global freelist. 281 Metachunk* chunk_freelist_allocate(size_t word_size); 282 283 // Map a size to a list index assuming that there are lists 284 // for special, small, medium, and humongous chunks. 285 ChunkIndex list_index(size_t size); 286 287 // Map a given index to the chunk size. 288 size_t size_by_index(ChunkIndex index) const; 289 290 bool is_class() const { return _is_class; } 291 292 // Convenience accessors. 293 size_t medium_chunk_word_size() const { return size_by_index(MediumIndex); } 294 size_t small_chunk_word_size() const { return size_by_index(SmallIndex); } 295 size_t specialized_chunk_word_size() const { return size_by_index(SpecializedIndex); } 296 297 // Take a chunk from the ChunkManager. The chunk is expected to be in 298 // the chunk manager (the freelist if non-humongous, the dictionary if 299 // humongous). 300 void remove_chunk(Metachunk* chunk); 301 302 // Return a single chunk of type index to the ChunkManager. 303 void return_single_chunk(ChunkIndex index, Metachunk* chunk); 304 305 // Add the simple linked list of chunks to the freelist of chunks 306 // of type index. 307 void return_chunk_list(ChunkIndex index, Metachunk* chunk); 308 309 // Total of the space in the free chunks list 310 size_t free_chunks_total_words(); 311 size_t free_chunks_total_bytes(); 312 313 // Number of chunks in the free chunks list 314 size_t free_chunks_count(); 315 316 // Remove from a list by size. Selects list based on size of chunk. 317 Metachunk* free_chunks_get(size_t chunk_word_size); 318 319 #define index_bounds_check(index) \ 320 assert(is_valid_chunktype(index), "Bad index: %d", (int) index) 321 322 size_t num_free_chunks(ChunkIndex index) const { 323 index_bounds_check(index); 324 325 if (index == HumongousIndex) { 326 return _humongous_dictionary.total_free_blocks(); 327 } 328 329 ssize_t count = _free_chunks[index].count(); 330 return count == -1 ? 0 : (size_t) count; 331 } 332 333 size_t size_free_chunks_in_bytes(ChunkIndex index) const { 334 index_bounds_check(index); 335 336 size_t word_size = 0; 337 if (index == HumongousIndex) { 338 word_size = _humongous_dictionary.total_size(); 339 } else { 340 const size_t size_per_chunk_in_words = _free_chunks[index].size(); 341 word_size = size_per_chunk_in_words * num_free_chunks(index); 342 } 343 344 return word_size * BytesPerWord; 345 } 346 347 MetaspaceChunkFreeListSummary chunk_free_list_summary() const { 348 return MetaspaceChunkFreeListSummary(num_free_chunks(SpecializedIndex), 349 num_free_chunks(SmallIndex), 350 num_free_chunks(MediumIndex), 351 num_free_chunks(HumongousIndex), 352 size_free_chunks_in_bytes(SpecializedIndex), 353 size_free_chunks_in_bytes(SmallIndex), 354 size_free_chunks_in_bytes(MediumIndex), 355 size_free_chunks_in_bytes(HumongousIndex)); 356 } 357 358 // Debug support 359 void verify(); 360 void slow_verify() { 361 if (VerifyMetaspace) { 362 verify(); 363 } 364 } 365 void locked_verify(); 366 void slow_locked_verify() { 367 if (VerifyMetaspace) { 368 locked_verify(); 369 } 370 } 371 void verify_free_chunks_total(); 372 373 void locked_print_free_chunks(outputStream* st); 374 void locked_print_sum_free_chunks(outputStream* st); 375 376 void print_on(outputStream* st) const; 377 378 // Fill in current statistic values to the given statistics object. 379 void collect_statistics(ChunkManagerStatistics* out) const; 380 381 }; 382 383 class SmallBlocks : public CHeapObj<mtClass> { 384 const static uint _small_block_max_size = sizeof(TreeChunk<Metablock, FreeList<Metablock> >)/HeapWordSize; 385 const static uint _small_block_min_size = sizeof(Metablock)/HeapWordSize; 386 387 private: 388 FreeList<Metablock> _small_lists[_small_block_max_size - _small_block_min_size]; 389 390 FreeList<Metablock>& list_at(size_t word_size) { 391 assert(word_size >= _small_block_min_size, "There are no metaspace objects less than %u words", _small_block_min_size); 392 return _small_lists[word_size - _small_block_min_size]; 393 } 394 395 public: 396 SmallBlocks() { 397 for (uint i = _small_block_min_size; i < _small_block_max_size; i++) { 398 uint k = i - _small_block_min_size; 399 _small_lists[k].set_size(i); 400 } 401 } 402 403 // Returns the total size, in words, of all blocks, across all block sizes. 404 size_t total_size() const { 405 size_t result = 0; 406 for (uint i = _small_block_min_size; i < _small_block_max_size; i++) { 407 uint k = i - _small_block_min_size; 408 result = result + _small_lists[k].count() * _small_lists[k].size(); 409 } 410 return result; 411 } 412 413 // Returns the total number of all blocks across all block sizes. 414 uintx total_num_blocks() const { 415 uintx result = 0; 416 for (uint i = _small_block_min_size; i < _small_block_max_size; i++) { 417 uint k = i - _small_block_min_size; 418 result = result + _small_lists[k].count(); 419 } 420 return result; 421 } 422 423 static uint small_block_max_size() { return _small_block_max_size; } 424 static uint small_block_min_size() { return _small_block_min_size; } 425 426 MetaWord* get_block(size_t word_size) { 427 if (list_at(word_size).count() > 0) { 428 MetaWord* new_block = (MetaWord*) list_at(word_size).get_chunk_at_head(); 429 return new_block; 430 } else { 431 return NULL; 432 } 433 } 434 void return_block(Metablock* free_chunk, size_t word_size) { 435 list_at(word_size).return_chunk_at_head(free_chunk, false); 436 assert(list_at(word_size).count() > 0, "Should have a chunk"); 437 } 438 439 void print_on(outputStream* st) const { 440 st->print_cr("SmallBlocks:"); 441 for (uint i = _small_block_min_size; i < _small_block_max_size; i++) { 442 uint k = i - _small_block_min_size; 443 st->print_cr("small_lists size " SIZE_FORMAT " count " SIZE_FORMAT, _small_lists[k].size(), _small_lists[k].count()); 444 } 445 } 446 }; 447 448 // Used to manage the free list of Metablocks (a block corresponds 449 // to the allocation of a quantum of metadata). 450 class BlockFreelist : public CHeapObj<mtClass> { 451 BlockTreeDictionary* const _dictionary; 452 SmallBlocks* _small_blocks; 453 454 // Only allocate and split from freelist if the size of the allocation 455 // is at least 1/4th the size of the available block. 456 const static int WasteMultiplier = 4; 457 458 // Accessors 459 BlockTreeDictionary* dictionary() const { return _dictionary; } 460 SmallBlocks* small_blocks() { 461 if (_small_blocks == NULL) { 462 _small_blocks = new SmallBlocks(); 463 } 464 return _small_blocks; 465 } 466 467 public: 468 BlockFreelist(); 469 ~BlockFreelist(); 470 471 // Get and return a block to the free list 472 MetaWord* get_block(size_t word_size); 473 void return_block(MetaWord* p, size_t word_size); 474 475 // Returns the total size, in words, of all blocks kept in this structure. 476 size_t total_size() const { 477 size_t result = dictionary()->total_size(); 478 if (_small_blocks != NULL) { 479 result = result + _small_blocks->total_size(); 480 } 481 return result; 482 } 483 484 // Returns the number of all blocks kept in this structure. 485 uintx num_blocks() const { 486 uintx result = dictionary()->total_free_blocks(); 487 if (_small_blocks != NULL) { 488 result = result + _small_blocks->total_num_blocks(); 489 } 490 return result; 491 } 492 493 static size_t min_dictionary_size() { return TreeChunk<Metablock, FreeList<Metablock> >::min_size(); } 494 void print_on(outputStream* st) const; 495 }; 496 497 // Helper for Occupancy Bitmap. A type trait to give an all-bits-are-one-unsigned constant. 498 template <typename T> struct all_ones { static const T value; }; 499 template <> struct all_ones <uint64_t> { static const uint64_t value = 0xFFFFFFFFFFFFFFFFULL; }; 500 template <> struct all_ones <uint32_t> { static const uint32_t value = 0xFFFFFFFF; }; 501 502 // The OccupancyMap is a bitmap which, for a given VirtualSpaceNode, 503 // keeps information about 504 // - where a chunk starts 505 // - whether a chunk is in-use or free 506 // A bit in this bitmap represents one range of memory in the smallest 507 // chunk size (SpecializedChunk or ClassSpecializedChunk). 508 class OccupancyMap : public CHeapObj<mtInternal> { 509 510 // The address range this map covers. 511 const MetaWord* const _reference_address; 512 const size_t _word_size; 513 514 // The word size of a specialized chunk, aka the number of words one 515 // bit in this map represents. 516 const size_t _smallest_chunk_word_size; 517 518 // map data 519 // Data are organized in two bit layers: 520 // The first layer is the chunk-start-map. Here, a bit is set to mark 521 // the corresponding region as the head of a chunk. 522 // The second layer is the in-use-map. Here, a set bit indicates that 523 // the corresponding belongs to a chunk which is in use. 524 uint8_t* _map[2]; 525 526 enum { layer_chunk_start_map = 0, layer_in_use_map = 1 }; 527 528 // length, in bytes, of bitmap data 529 size_t _map_size; 530 531 // Returns true if bit at position pos at bit-layer layer is set. 532 bool get_bit_at_position(unsigned pos, unsigned layer) const { 533 assert(layer == 0 || layer == 1, "Invalid layer %d", layer); 534 const unsigned byteoffset = pos / 8; 535 assert(byteoffset < _map_size, 536 "invalid byte offset (%u), map size is " SIZE_FORMAT ".", byteoffset, _map_size); 537 const unsigned mask = 1 << (pos % 8); 538 return (_map[layer][byteoffset] & mask) > 0; 539 } 540 541 // Changes bit at position pos at bit-layer layer to value v. 542 void set_bit_at_position(unsigned pos, unsigned layer, bool v) { 543 assert(layer == 0 || layer == 1, "Invalid layer %d", layer); 544 const unsigned byteoffset = pos / 8; 545 assert(byteoffset < _map_size, 546 "invalid byte offset (%u), map size is " SIZE_FORMAT ".", byteoffset, _map_size); 547 const unsigned mask = 1 << (pos % 8); 548 if (v) { 549 _map[layer][byteoffset] |= mask; 550 } else { 551 _map[layer][byteoffset] &= ~mask; 552 } 553 } 554 555 // Optimized case of is_any_bit_set_in_region for 32/64bit aligned access: 556 // pos is 32/64 aligned and num_bits is 32/64. 557 // This is the typical case when coalescing to medium chunks, whose size is 558 // 32 or 64 times the specialized chunk size (depending on class or non class 559 // case), so they occupy 64 bits which should be 64bit aligned, because 560 // chunks are chunk-size aligned. 561 template <typename T> 562 bool is_any_bit_set_in_region_3264(unsigned pos, unsigned num_bits, unsigned layer) const { 563 assert(_map_size > 0, "not initialized"); 564 assert(layer == 0 || layer == 1, "Invalid layer %d.", layer); 565 assert(pos % (sizeof(T) * 8) == 0, "Bit position must be aligned (%u).", pos); 566 assert(num_bits == (sizeof(T) * 8), "Number of bits incorrect (%u).", num_bits); 567 const size_t byteoffset = pos / 8; 568 assert(byteoffset <= (_map_size - sizeof(T)), 569 "Invalid byte offset (" SIZE_FORMAT "), map size is " SIZE_FORMAT ".", byteoffset, _map_size); 570 const T w = *(T*)(_map[layer] + byteoffset); 571 return w > 0 ? true : false; 572 } 573 574 // Returns true if any bit in region [pos1, pos1 + num_bits) is set in bit-layer layer. 575 bool is_any_bit_set_in_region(unsigned pos, unsigned num_bits, unsigned layer) const { 576 if (pos % 32 == 0 && num_bits == 32) { 577 return is_any_bit_set_in_region_3264<uint32_t>(pos, num_bits, layer); 578 } else if (pos % 64 == 0 && num_bits == 64) { 579 return is_any_bit_set_in_region_3264<uint64_t>(pos, num_bits, layer); 580 } else { 581 for (unsigned n = 0; n < num_bits; n ++) { 582 if (get_bit_at_position(pos + n, layer)) { 583 return true; 584 } 585 } 586 } 587 return false; 588 } 589 590 // Returns true if any bit in region [p, p+word_size) is set in bit-layer layer. 591 bool is_any_bit_set_in_region(MetaWord* p, size_t word_size, unsigned layer) const { 592 assert(word_size % _smallest_chunk_word_size == 0, 593 "Region size " SIZE_FORMAT " not a multiple of smallest chunk size.", word_size); 594 const unsigned pos = get_bitpos_for_address(p); 595 const unsigned num_bits = (unsigned) (word_size / _smallest_chunk_word_size); 596 return is_any_bit_set_in_region(pos, num_bits, layer); 597 } 598 599 // Optimized case of set_bits_of_region for 32/64bit aligned access: 600 // pos is 32/64 aligned and num_bits is 32/64. 601 // This is the typical case when coalescing to medium chunks, whose size 602 // is 32 or 64 times the specialized chunk size (depending on class or non 603 // class case), so they occupy 64 bits which should be 64bit aligned, 604 // because chunks are chunk-size aligned. 605 template <typename T> 606 void set_bits_of_region_T(unsigned pos, unsigned num_bits, unsigned layer, bool v) { 607 assert(pos % (sizeof(T) * 8) == 0, "Bit position must be aligned to %u (%u).", 608 (unsigned)(sizeof(T) * 8), pos); 609 assert(num_bits == (sizeof(T) * 8), "Number of bits incorrect (%u), expected %u.", 610 num_bits, (unsigned)(sizeof(T) * 8)); 611 const size_t byteoffset = pos / 8; 612 assert(byteoffset <= (_map_size - sizeof(T)), 613 "invalid byte offset (" SIZE_FORMAT "), map size is " SIZE_FORMAT ".", byteoffset, _map_size); 614 T* const pw = (T*)(_map[layer] + byteoffset); 615 *pw = v ? all_ones<T>::value : (T) 0; 616 } 617 618 // Set all bits in a region starting at pos to a value. 619 void set_bits_of_region(unsigned pos, unsigned num_bits, unsigned layer, bool v) { 620 assert(_map_size > 0, "not initialized"); 621 assert(layer == 0 || layer == 1, "Invalid layer %d.", layer); 622 if (pos % 32 == 0 && num_bits == 32) { 623 set_bits_of_region_T<uint32_t>(pos, num_bits, layer, v); 624 } else if (pos % 64 == 0 && num_bits == 64) { 625 set_bits_of_region_T<uint64_t>(pos, num_bits, layer, v); 626 } else { 627 for (unsigned n = 0; n < num_bits; n ++) { 628 set_bit_at_position(pos + n, layer, v); 629 } 630 } 631 } 632 633 // Helper: sets all bits in a region [p, p+word_size). 634 void set_bits_of_region(MetaWord* p, size_t word_size, unsigned layer, bool v) { 635 assert(word_size % _smallest_chunk_word_size == 0, 636 "Region size " SIZE_FORMAT " not a multiple of smallest chunk size.", word_size); 637 const unsigned pos = get_bitpos_for_address(p); 638 const unsigned num_bits = (unsigned) (word_size / _smallest_chunk_word_size); 639 set_bits_of_region(pos, num_bits, layer, v); 640 } 641 642 // Helper: given an address, return the bit position representing that address. 643 unsigned get_bitpos_for_address(const MetaWord* p) const { 644 assert(_reference_address != NULL, "not initialized"); 645 assert(p >= _reference_address && p < _reference_address + _word_size, 646 "Address %p out of range for occupancy map [%p..%p).", 647 p, _reference_address, _reference_address + _word_size); 648 assert(is_aligned(p, _smallest_chunk_word_size * sizeof(MetaWord)), 649 "Address not aligned (%p).", p); 650 const ptrdiff_t d = (p - _reference_address) / _smallest_chunk_word_size; 651 assert(d >= 0 && (size_t)d < _map_size * 8, "Sanity."); 652 return (unsigned) d; 653 } 654 655 public: 656 657 OccupancyMap(const MetaWord* reference_address, size_t word_size, size_t smallest_chunk_word_size) : 658 _reference_address(reference_address), _word_size(word_size), 659 _smallest_chunk_word_size(smallest_chunk_word_size) { 660 assert(reference_address != NULL, "invalid reference address"); 661 assert(is_aligned(reference_address, smallest_chunk_word_size), 662 "Reference address not aligned to smallest chunk size."); 663 assert(is_aligned(word_size, smallest_chunk_word_size), 664 "Word_size shall be a multiple of the smallest chunk size."); 665 // Calculate bitmap size: one bit per smallest_chunk_word_size'd area. 666 size_t num_bits = word_size / smallest_chunk_word_size; 667 _map_size = (num_bits + 7) / 8; 668 assert(_map_size * 8 >= num_bits, "sanity"); 669 _map[0] = (uint8_t*) os::malloc(_map_size, mtInternal); 670 _map[1] = (uint8_t*) os::malloc(_map_size, mtInternal); 671 assert(_map[0] != NULL && _map[1] != NULL, "Occupancy Map: allocation failed."); 672 memset(_map[1], 0, _map_size); 673 memset(_map[0], 0, _map_size); 674 // Sanity test: the first respectively last possible chunk start address in 675 // the covered range shall map to the first and last bit in the bitmap. 676 assert(get_bitpos_for_address(reference_address) == 0, 677 "First chunk address in range must map to fist bit in bitmap."); 678 assert(get_bitpos_for_address(reference_address + word_size - smallest_chunk_word_size) == num_bits - 1, 679 "Last chunk address in range must map to last bit in bitmap."); 680 } 681 682 ~OccupancyMap() { 683 os::free(_map[0]); 684 os::free(_map[1]); 685 } 686 687 // Returns true if at address x a chunk is starting. 688 bool chunk_starts_at_address(MetaWord* p) const { 689 const unsigned pos = get_bitpos_for_address(p); 690 return get_bit_at_position(pos, layer_chunk_start_map); 691 } 692 693 void set_chunk_starts_at_address(MetaWord* p, bool v) { 694 const unsigned pos = get_bitpos_for_address(p); 695 set_bit_at_position(pos, layer_chunk_start_map, v); 696 } 697 698 // Removes all chunk-start-bits inside a region, typically as a 699 // result of a chunk merge. 700 void wipe_chunk_start_bits_in_region(MetaWord* p, size_t word_size) { 701 set_bits_of_region(p, word_size, layer_chunk_start_map, false); 702 } 703 704 // Returns true if there are life (in use) chunks in the region limited 705 // by [p, p+word_size). 706 bool is_region_in_use(MetaWord* p, size_t word_size) const { 707 return is_any_bit_set_in_region(p, word_size, layer_in_use_map); 708 } 709 710 // Marks the region starting at p with the size word_size as in use 711 // or free, depending on v. 712 void set_region_in_use(MetaWord* p, size_t word_size, bool v) { 713 set_bits_of_region(p, word_size, layer_in_use_map, v); 714 } 715 716 #ifdef ASSERT 717 // Verify occupancy map for the address range [from, to). 718 // We need to tell it the address range, because the memory the 719 // occupancy map is covering may not be fully comitted yet. 720 void verify(MetaWord* from, MetaWord* to) { 721 Metachunk* chunk = NULL; 722 int nth_bit_for_chunk = 0; 723 MetaWord* chunk_end = NULL; 724 for (MetaWord* p = from; p < to; p += _smallest_chunk_word_size) { 725 const unsigned pos = get_bitpos_for_address(p); 726 // Check the chunk-starts-info: 727 if (get_bit_at_position(pos, layer_chunk_start_map)) { 728 // Chunk start marked in bitmap. 729 chunk = (Metachunk*) p; 730 if (chunk_end != NULL) { 731 assert(chunk_end == p, "Unexpected chunk start found at %p (expected " 732 "the next chunk to start at %p).", p, chunk_end); 733 } 734 assert(chunk->is_valid_sentinel(), "Invalid chunk at address %p.", p); 735 if (chunk->get_chunk_type() != HumongousIndex) { 736 guarantee(is_aligned(p, chunk->word_size()), "Chunk %p not aligned.", p); 737 } 738 chunk_end = p + chunk->word_size(); 739 nth_bit_for_chunk = 0; 740 assert(chunk_end <= to, "Chunk end overlaps test address range."); 741 } else { 742 // No chunk start marked in bitmap. 743 assert(chunk != NULL, "Chunk should start at start of address range."); 744 assert(p < chunk_end, "Did not find expected chunk start at %p.", p); 745 nth_bit_for_chunk ++; 746 } 747 // Check the in-use-info: 748 const bool in_use_bit = get_bit_at_position(pos, layer_in_use_map); 749 if (in_use_bit) { 750 assert(!chunk->is_tagged_free(), "Chunk %p: marked in-use in map but is free (bit %u).", 751 chunk, nth_bit_for_chunk); 752 } else { 753 assert(chunk->is_tagged_free(), "Chunk %p: marked free in map but is in use (bit %u).", 754 chunk, nth_bit_for_chunk); 755 } 756 } 757 } 758 759 // Verify that a given chunk is correctly accounted for in the bitmap. 760 void verify_for_chunk(Metachunk* chunk) { 761 assert(chunk_starts_at_address((MetaWord*) chunk), 762 "No chunk start marked in map for chunk %p.", chunk); 763 // For chunks larger than the minimal chunk size, no other chunk 764 // must start in its area. 765 if (chunk->word_size() > _smallest_chunk_word_size) { 766 assert(!is_any_bit_set_in_region(((MetaWord*) chunk) + _smallest_chunk_word_size, 767 chunk->word_size() - _smallest_chunk_word_size, layer_chunk_start_map), 768 "No chunk must start within another chunk."); 769 } 770 if (!chunk->is_tagged_free()) { 771 assert(is_region_in_use((MetaWord*)chunk, chunk->word_size()), 772 "Chunk %p is in use but marked as free in map (%d %d).", 773 chunk, chunk->get_chunk_type(), chunk->get_origin()); 774 } else { 775 assert(!is_region_in_use((MetaWord*)chunk, chunk->word_size()), 776 "Chunk %p is free but marked as in-use in map (%d %d).", 777 chunk, chunk->get_chunk_type(), chunk->get_origin()); 778 } 779 } 780 781 #endif // ASSERT 782 783 }; 784 785 // A VirtualSpaceList node. 786 class VirtualSpaceNode : public CHeapObj<mtClass> { 787 friend class VirtualSpaceList; 788 789 // Link to next VirtualSpaceNode 790 VirtualSpaceNode* _next; 791 792 // Whether this node is contained in class or metaspace. 793 const bool _is_class; 794 795 // total in the VirtualSpace 796 MemRegion _reserved; 797 ReservedSpace _rs; 798 VirtualSpace _virtual_space; 799 MetaWord* _top; 800 // count of chunks contained in this VirtualSpace 801 uintx _container_count; 802 803 OccupancyMap* _occupancy_map; 804 805 // Convenience functions to access the _virtual_space 806 char* low() const { return virtual_space()->low(); } 807 char* high() const { return virtual_space()->high(); } 808 809 // The first Metachunk will be allocated at the bottom of the 810 // VirtualSpace 811 Metachunk* first_chunk() { return (Metachunk*) bottom(); } 812 813 // Committed but unused space in the virtual space 814 size_t free_words_in_vs() const; 815 816 // True if this node belongs to class metaspace. 817 bool is_class() const { return _is_class; } 818 819 // Helper function for take_from_committed: allocate padding chunks 820 // until top is at the given address. 821 void allocate_padding_chunks_until_top_is_at(MetaWord* target_top); 822 823 public: 824 825 VirtualSpaceNode(bool is_class, size_t byte_size); 826 VirtualSpaceNode(bool is_class, ReservedSpace rs) : 827 _is_class(is_class), _top(NULL), _next(NULL), _rs(rs), _container_count(0), _occupancy_map(NULL) {} 828 ~VirtualSpaceNode(); 829 830 // Convenience functions for logical bottom and end 831 MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); } 832 MetaWord* end() const { return (MetaWord*) _virtual_space.high(); } 833 834 const OccupancyMap* occupancy_map() const { return _occupancy_map; } 835 OccupancyMap* occupancy_map() { return _occupancy_map; } 836 837 bool contains(const void* ptr) { return ptr >= low() && ptr < high(); } 838 839 size_t reserved_words() const { return _virtual_space.reserved_size() / BytesPerWord; } 840 size_t committed_words() const { return _virtual_space.actual_committed_size() / BytesPerWord; } 841 842 bool is_pre_committed() const { return _virtual_space.special(); } 843 844 // address of next available space in _virtual_space; 845 // Accessors 846 VirtualSpaceNode* next() { return _next; } 847 void set_next(VirtualSpaceNode* v) { _next = v; } 848 849 void set_reserved(MemRegion const v) { _reserved = v; } 850 void set_top(MetaWord* v) { _top = v; } 851 852 // Accessors 853 MemRegion* reserved() { return &_reserved; } 854 VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; } 855 856 // Returns true if "word_size" is available in the VirtualSpace 857 bool is_available(size_t word_size) { return word_size <= pointer_delta(end(), _top, sizeof(MetaWord)); } 858 859 MetaWord* top() const { return _top; } 860 void inc_top(size_t word_size) { _top += word_size; } 861 862 uintx container_count() { return _container_count; } 863 void inc_container_count(); 864 void dec_container_count(); 865 #ifdef ASSERT 866 uintx container_count_slow(); 867 void verify_container_count(); 868 #endif 869 870 // used and capacity in this single entry in the list 871 size_t used_words_in_vs() const; 872 size_t capacity_words_in_vs() const; 873 874 bool initialize(); 875 876 // get space from the virtual space 877 Metachunk* take_from_committed(size_t chunk_word_size); 878 879 // Allocate a chunk from the virtual space and return it. 880 Metachunk* get_chunk_vs(size_t chunk_word_size); 881 882 // Expands/shrinks the committed space in a virtual space. Delegates 883 // to Virtualspace 884 bool expand_by(size_t min_words, size_t preferred_words); 885 886 // In preparation for deleting this node, remove all the chunks 887 // in the node from any freelist. 888 void purge(ChunkManager* chunk_manager); 889 890 // If an allocation doesn't fit in the current node a new node is created. 891 // Allocate chunks out of the remaining committed space in this node 892 // to avoid wasting that memory. 893 // This always adds up because all the chunk sizes are multiples of 894 // the smallest chunk size. 895 void retire(ChunkManager* chunk_manager); 896 897 898 void print_on(outputStream* st) const { print_on(st, K); } 899 void print_on(outputStream* st, size_t scale) const; 900 void print_map(outputStream* st, bool is_class) const; 901 902 // Debug support 903 DEBUG_ONLY(void mangle();) 904 // Verify counters, all chunks in this list node and the occupancy map. 905 DEBUG_ONLY(void verify();) 906 // Verify that all free chunks in this node are ideally merged 907 // (there not should be multiple small chunks where a large chunk could exist.) 908 DEBUG_ONLY(void verify_free_chunks_are_ideally_merged();) 909 910 }; 911 912 #define assert_is_aligned(value, alignment) \ 913 assert(is_aligned((value), (alignment)), \ 914 SIZE_FORMAT_HEX " is not aligned to " \ 915 SIZE_FORMAT, (size_t)(uintptr_t)value, (alignment)) 916 917 #define assert_counter(expected_value, real_value, msg) \ 918 assert( (expected_value) == (real_value), \ 919 "Counter mismatch (%s): expected " SIZE_FORMAT \ 920 ", but got: " SIZE_FORMAT ".", msg, expected_value, \ 921 real_value); 922 923 // Decide if large pages should be committed when the memory is reserved. 924 static bool should_commit_large_pages_when_reserving(size_t bytes) { 925 if (UseLargePages && UseLargePagesInMetaspace && !os::can_commit_large_page_memory()) { 926 size_t words = bytes / BytesPerWord; 927 bool is_class = false; // We never reserve large pages for the class space. 928 if (MetaspaceGC::can_expand(words, is_class) && 929 MetaspaceGC::allowed_expansion() >= words) { 930 return true; 931 } 932 } 933 934 return false; 935 } 936 937 // byte_size is the size of the associated virtualspace. 938 VirtualSpaceNode::VirtualSpaceNode(bool is_class, size_t bytes) : 939 _is_class(is_class), _top(NULL), _next(NULL), _rs(), _container_count(0), _occupancy_map(NULL) { 940 assert_is_aligned(bytes, Metaspace::reserve_alignment()); 941 bool large_pages = should_commit_large_pages_when_reserving(bytes); 942 _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages); 943 944 if (_rs.is_reserved()) { 945 assert(_rs.base() != NULL, "Catch if we get a NULL address"); 946 assert(_rs.size() != 0, "Catch if we get a 0 size"); 947 assert_is_aligned(_rs.base(), Metaspace::reserve_alignment()); 948 assert_is_aligned(_rs.size(), Metaspace::reserve_alignment()); 949 950 MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass); 951 } 952 } 953 954 void VirtualSpaceNode::purge(ChunkManager* chunk_manager) { 955 DEBUG_ONLY(this->verify();) 956 Metachunk* chunk = first_chunk(); 957 Metachunk* invalid_chunk = (Metachunk*) top(); 958 while (chunk < invalid_chunk ) { 959 assert(chunk->is_tagged_free(), "Should be tagged free"); 960 MetaWord* next = ((MetaWord*)chunk) + chunk->word_size(); 961 chunk_manager->remove_chunk(chunk); 962 chunk->remove_sentinel(); 963 assert(chunk->next() == NULL && 964 chunk->prev() == NULL, 965 "Was not removed from its list"); 966 chunk = (Metachunk*) next; 967 } 968 } 969 970 void VirtualSpaceNode::print_map(outputStream* st, bool is_class) const { 971 972 if (bottom() == top()) { 973 return; 974 } 975 976 const size_t spec_chunk_size = is_class ? ClassSpecializedChunk : SpecializedChunk; 977 const size_t small_chunk_size = is_class ? ClassSmallChunk : SmallChunk; 978 const size_t med_chunk_size = is_class ? ClassMediumChunk : MediumChunk; 979 980 int line_len = 100; 981 const size_t section_len = align_up(spec_chunk_size * line_len, med_chunk_size); 982 line_len = (int)(section_len / spec_chunk_size); 983 984 static const int NUM_LINES = 4; 985 986 char* lines[NUM_LINES]; 987 for (int i = 0; i < NUM_LINES; i ++) { 988 lines[i] = (char*)os::malloc(line_len, mtInternal); 989 } 990 int pos = 0; 991 const MetaWord* p = bottom(); 992 const Metachunk* chunk = (const Metachunk*)p; 993 const MetaWord* chunk_end = p + chunk->word_size(); 994 while (p < top()) { 995 if (pos == line_len) { 996 pos = 0; 997 for (int i = 0; i < NUM_LINES; i ++) { 998 st->fill_to(22); 999 st->print_raw(lines[i], line_len); 1000 st->cr(); 1001 } 1002 } 1003 if (pos == 0) { 1004 st->print(PTR_FORMAT ":", p2i(p)); 1005 } 1006 if (p == chunk_end) { 1007 chunk = (Metachunk*)p; 1008 chunk_end = p + chunk->word_size(); 1009 } 1010 // line 1: chunk starting points (a dot if that area is a chunk start). 1011 lines[0][pos] = p == (const MetaWord*)chunk ? '.' : ' '; 1012 1013 // Line 2: chunk type (x=spec, s=small, m=medium, h=humongous), uppercase if 1014 // chunk is in use. 1015 const bool chunk_is_free = ((Metachunk*)chunk)->is_tagged_free(); 1016 if (chunk->word_size() == spec_chunk_size) { 1017 lines[1][pos] = chunk_is_free ? 'x' : 'X'; 1018 } else if (chunk->word_size() == small_chunk_size) { 1019 lines[1][pos] = chunk_is_free ? 's' : 'S'; 1020 } else if (chunk->word_size() == med_chunk_size) { 1021 lines[1][pos] = chunk_is_free ? 'm' : 'M'; 1022 } else if (chunk->word_size() > med_chunk_size) { 1023 lines[1][pos] = chunk_is_free ? 'h' : 'H'; 1024 } else { 1025 ShouldNotReachHere(); 1026 } 1027 1028 // Line 3: chunk origin 1029 const ChunkOrigin origin = chunk->get_origin(); 1030 lines[2][pos] = origin == origin_normal ? ' ' : '0' + (int) origin; 1031 1032 // Line 4: Virgin chunk? Virgin chunks are chunks created as a byproduct of padding or splitting, 1033 // but were never used. 1034 lines[3][pos] = chunk->get_use_count() > 0 ? ' ' : 'v'; 1035 1036 p += spec_chunk_size; 1037 pos ++; 1038 } 1039 if (pos > 0) { 1040 for (int i = 0; i < NUM_LINES; i ++) { 1041 st->fill_to(22); 1042 st->print_raw(lines[i], line_len); 1043 st->cr(); 1044 } 1045 } 1046 for (int i = 0; i < NUM_LINES; i ++) { 1047 os::free(lines[i]); 1048 } 1049 } 1050 1051 1052 #ifdef ASSERT 1053 uintx VirtualSpaceNode::container_count_slow() { 1054 uintx count = 0; 1055 Metachunk* chunk = first_chunk(); 1056 Metachunk* invalid_chunk = (Metachunk*) top(); 1057 while (chunk < invalid_chunk ) { 1058 MetaWord* next = ((MetaWord*)chunk) + chunk->word_size(); 1059 do_verify_chunk(chunk); 1060 // Don't count the chunks on the free lists. Those are 1061 // still part of the VirtualSpaceNode but not currently 1062 // counted. 1063 if (!chunk->is_tagged_free()) { 1064 count++; 1065 } 1066 chunk = (Metachunk*) next; 1067 } 1068 return count; 1069 } 1070 #endif 1071 1072 #ifdef ASSERT 1073 // Verify counters, all chunks in this list node and the occupancy map. 1074 void VirtualSpaceNode::verify() { 1075 uintx num_in_use_chunks = 0; 1076 Metachunk* chunk = first_chunk(); 1077 Metachunk* invalid_chunk = (Metachunk*) top(); 1078 1079 // Iterate the chunks in this node and verify each chunk. 1080 while (chunk < invalid_chunk ) { 1081 DEBUG_ONLY(do_verify_chunk(chunk);) 1082 if (!chunk->is_tagged_free()) { 1083 num_in_use_chunks ++; 1084 } 1085 MetaWord* next = ((MetaWord*)chunk) + chunk->word_size(); 1086 chunk = (Metachunk*) next; 1087 } 1088 assert(_container_count == num_in_use_chunks, "Container count mismatch (real: " UINTX_FORMAT 1089 ", counter: " UINTX_FORMAT ".", num_in_use_chunks, _container_count); 1090 // Also verify the occupancy map. 1091 occupancy_map()->verify(this->bottom(), this->top()); 1092 } 1093 #endif // ASSERT 1094 1095 #ifdef ASSERT 1096 // Verify that all free chunks in this node are ideally merged 1097 // (there not should be multiple small chunks where a large chunk could exist.) 1098 void VirtualSpaceNode::verify_free_chunks_are_ideally_merged() { 1099 Metachunk* chunk = first_chunk(); 1100 Metachunk* invalid_chunk = (Metachunk*) top(); 1101 // Shorthands. 1102 const size_t size_med = (is_class() ? ClassMediumChunk : MediumChunk) * BytesPerWord; 1103 const size_t size_small = (is_class() ? ClassSmallChunk : SmallChunk) * BytesPerWord; 1104 int num_free_chunks_since_last_med_boundary = -1; 1105 int num_free_chunks_since_last_small_boundary = -1; 1106 while (chunk < invalid_chunk ) { 1107 // Test for missed chunk merge opportunities: count number of free chunks since last chunk boundary. 1108 // Reset the counter when encountering a non-free chunk. 1109 if (chunk->get_chunk_type() != HumongousIndex) { 1110 if (chunk->is_tagged_free()) { 1111 // Count successive free, non-humongous chunks. 1112 if (is_aligned(chunk, size_small)) { 1113 assert(num_free_chunks_since_last_small_boundary <= 1, 1114 "Missed chunk merge opportunity at " PTR_FORMAT " for chunk size " SIZE_FORMAT_HEX ".", p2i(chunk) - size_small, size_small); 1115 num_free_chunks_since_last_small_boundary = 0; 1116 } else if (num_free_chunks_since_last_small_boundary != -1) { 1117 num_free_chunks_since_last_small_boundary ++; 1118 } 1119 if (is_aligned(chunk, size_med)) { 1120 assert(num_free_chunks_since_last_med_boundary <= 1, 1121 "Missed chunk merge opportunity at " PTR_FORMAT " for chunk size " SIZE_FORMAT_HEX ".", p2i(chunk) - size_med, size_med); 1122 num_free_chunks_since_last_med_boundary = 0; 1123 } else if (num_free_chunks_since_last_med_boundary != -1) { 1124 num_free_chunks_since_last_med_boundary ++; 1125 } 1126 } else { 1127 // Encountering a non-free chunk, reset counters. 1128 num_free_chunks_since_last_med_boundary = -1; 1129 num_free_chunks_since_last_small_boundary = -1; 1130 } 1131 } else { 1132 // One cannot merge areas with a humongous chunk in the middle. Reset counters. 1133 num_free_chunks_since_last_med_boundary = -1; 1134 num_free_chunks_since_last_small_boundary = -1; 1135 } 1136 1137 MetaWord* next = ((MetaWord*)chunk) + chunk->word_size(); 1138 chunk = (Metachunk*) next; 1139 } 1140 } 1141 #endif // ASSERT 1142 1143 // List of VirtualSpaces for metadata allocation. 1144 class VirtualSpaceList : public CHeapObj<mtClass> { 1145 friend class VirtualSpaceNode; 1146 1147 enum VirtualSpaceSizes { 1148 VirtualSpaceSize = 256 * K 1149 }; 1150 1151 // Head of the list 1152 VirtualSpaceNode* _virtual_space_list; 1153 // virtual space currently being used for allocations 1154 VirtualSpaceNode* _current_virtual_space; 1155 1156 // Is this VirtualSpaceList used for the compressed class space 1157 bool _is_class; 1158 1159 // Sum of reserved and committed memory in the virtual spaces 1160 size_t _reserved_words; 1161 size_t _committed_words; 1162 1163 // Number of virtual spaces 1164 size_t _virtual_space_count; 1165 1166 ~VirtualSpaceList(); 1167 1168 VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; } 1169 1170 void set_virtual_space_list(VirtualSpaceNode* v) { 1171 _virtual_space_list = v; 1172 } 1173 void set_current_virtual_space(VirtualSpaceNode* v) { 1174 _current_virtual_space = v; 1175 } 1176 1177 void link_vs(VirtualSpaceNode* new_entry); 1178 1179 // Get another virtual space and add it to the list. This 1180 // is typically prompted by a failed attempt to allocate a chunk 1181 // and is typically followed by the allocation of a chunk. 1182 bool create_new_virtual_space(size_t vs_word_size); 1183 1184 // Chunk up the unused committed space in the current 1185 // virtual space and add the chunks to the free list. 1186 void retire_current_virtual_space(); 1187 1188 public: 1189 VirtualSpaceList(size_t word_size); 1190 VirtualSpaceList(ReservedSpace rs); 1191 1192 size_t free_bytes(); 1193 1194 Metachunk* get_new_chunk(size_t chunk_word_size, 1195 size_t suggested_commit_granularity); 1196 1197 bool expand_node_by(VirtualSpaceNode* node, 1198 size_t min_words, 1199 size_t preferred_words); 1200 1201 bool expand_by(size_t min_words, 1202 size_t preferred_words); 1203 1204 VirtualSpaceNode* current_virtual_space() { 1205 return _current_virtual_space; 1206 } 1207 1208 bool is_class() const { return _is_class; } 1209 1210 bool initialization_succeeded() { return _virtual_space_list != NULL; } 1211 1212 size_t reserved_words() { return _reserved_words; } 1213 size_t reserved_bytes() { return reserved_words() * BytesPerWord; } 1214 size_t committed_words() { return _committed_words; } 1215 size_t committed_bytes() { return committed_words() * BytesPerWord; } 1216 1217 void inc_reserved_words(size_t v); 1218 void dec_reserved_words(size_t v); 1219 void inc_committed_words(size_t v); 1220 void dec_committed_words(size_t v); 1221 void inc_virtual_space_count(); 1222 void dec_virtual_space_count(); 1223 1224 bool contains(const void* ptr); 1225 1226 // Unlink empty VirtualSpaceNodes and free it. 1227 void purge(ChunkManager* chunk_manager); 1228 1229 void print_on(outputStream* st) const { print_on(st, K); } 1230 void print_on(outputStream* st, size_t scale) const; 1231 void print_map(outputStream* st) const; 1232 1233 class VirtualSpaceListIterator : public StackObj { 1234 VirtualSpaceNode* _virtual_spaces; 1235 public: 1236 VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) : 1237 _virtual_spaces(virtual_spaces) {} 1238 1239 bool repeat() { 1240 return _virtual_spaces != NULL; 1241 } 1242 1243 VirtualSpaceNode* get_next() { 1244 VirtualSpaceNode* result = _virtual_spaces; 1245 if (_virtual_spaces != NULL) { 1246 _virtual_spaces = _virtual_spaces->next(); 1247 } 1248 return result; 1249 } 1250 }; 1251 }; 1252 1253 class Metadebug : AllStatic { 1254 // Debugging support for Metaspaces 1255 static int _allocation_fail_alot_count; 1256 1257 public: 1258 1259 static void init_allocation_fail_alot_count(); 1260 #ifdef ASSERT 1261 static bool test_metadata_failure(); 1262 #endif 1263 }; 1264 1265 int Metadebug::_allocation_fail_alot_count = 0; 1266 1267 1268 // SpaceManager - used by Metaspace to handle allocations 1269 class SpaceManager : public CHeapObj<mtClass> { 1270 friend class ClassLoaderMetaspace; 1271 friend class Metadebug; 1272 1273 private: 1274 1275 // protects allocations 1276 Mutex* const _lock; 1277 1278 // Type of metadata allocated. 1279 const Metaspace::MetadataType _mdtype; 1280 1281 // Type of metaspace 1282 const Metaspace::MetaspaceType _space_type; 1283 1284 // List of chunks in use by this SpaceManager. Allocations 1285 // are done from the current chunk. The list is used for deallocating 1286 // chunks when the SpaceManager is freed. 1287 Metachunk* _chunks_in_use[NumberOfInUseLists]; 1288 Metachunk* _current_chunk; 1289 1290 // Maximum number of small chunks to allocate to a SpaceManager 1291 static uint const _small_chunk_limit; 1292 1293 // Maximum number of specialize chunks to allocate for anonymous and delegating 1294 // metadata space to a SpaceManager 1295 static uint const _anon_and_delegating_metadata_specialize_chunk_limit; 1296 1297 // Some running counters, but lets keep their number small to not add to much to 1298 // the per-classloader footprint. 1299 // Note: capacity = used + free + waste + overhead. We do not keep running counters for 1300 // free and waste. Their sum can be deduced from the three other values. 1301 size_t _overhead_words; 1302 size_t _capacity_words; 1303 size_t _used_words; 1304 1305 // Free lists of blocks are per SpaceManager since they 1306 // are assumed to be in chunks in use by the SpaceManager 1307 // and all chunks in use by a SpaceManager are freed when 1308 // the class loader using the SpaceManager is collected. 1309 BlockFreelist* _block_freelists; 1310 1311 private: 1312 // Accessors 1313 Metachunk* chunks_in_use(ChunkIndex index) const { return _chunks_in_use[index]; } 1314 void set_chunks_in_use(ChunkIndex index, Metachunk* v) { 1315 _chunks_in_use[index] = v; 1316 } 1317 1318 BlockFreelist* block_freelists() const { return _block_freelists; } 1319 1320 Metaspace::MetadataType mdtype() { return _mdtype; } 1321 1322 VirtualSpaceList* vs_list() const { return Metaspace::get_space_list(_mdtype); } 1323 ChunkManager* chunk_manager() const { return Metaspace::get_chunk_manager(_mdtype); } 1324 1325 Metachunk* current_chunk() const { return _current_chunk; } 1326 void set_current_chunk(Metachunk* v) { 1327 _current_chunk = v; 1328 } 1329 1330 Metachunk* find_current_chunk(size_t word_size); 1331 1332 // Add chunk to the list of chunks in use 1333 void add_chunk(Metachunk* v, bool make_current); 1334 void retire_current_chunk(); 1335 1336 Mutex* lock() const { return _lock; } 1337 1338 // Adds to the given statistic object. Expects to be locked with lock(). 1339 void add_to_statistics_locked(SpaceManagerStatistics* out) const; 1340 1341 // Verify internal counters against the current state. Expects to be locked with lock(). 1342 DEBUG_ONLY(void verify_metrics_locked() const;) 1343 1344 protected: 1345 void initialize(); 1346 1347 public: 1348 SpaceManager(Metaspace::MetadataType mdtype, 1349 Metaspace::MetaspaceType space_type, 1350 Mutex* lock); 1351 ~SpaceManager(); 1352 1353 enum ChunkMultiples { 1354 MediumChunkMultiple = 4 1355 }; 1356 1357 static size_t specialized_chunk_size(bool is_class) { return is_class ? ClassSpecializedChunk : SpecializedChunk; } 1358 static size_t small_chunk_size(bool is_class) { return is_class ? ClassSmallChunk : SmallChunk; } 1359 static size_t medium_chunk_size(bool is_class) { return is_class ? ClassMediumChunk : MediumChunk; } 1360 1361 static size_t smallest_chunk_size(bool is_class) { return specialized_chunk_size(is_class); } 1362 1363 // Accessors 1364 bool is_class() const { return _mdtype == Metaspace::ClassType; } 1365 1366 size_t specialized_chunk_size() const { return specialized_chunk_size(is_class()); } 1367 size_t small_chunk_size() const { return small_chunk_size(is_class()); } 1368 size_t medium_chunk_size() const { return medium_chunk_size(is_class()); } 1369 1370 size_t smallest_chunk_size() const { return smallest_chunk_size(is_class()); } 1371 1372 size_t medium_chunk_bunch() const { return medium_chunk_size() * MediumChunkMultiple; } 1373 1374 bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); } 1375 1376 size_t capacity_words() const { return _capacity_words; } 1377 size_t used_words() const { return _used_words; } 1378 size_t overhead_words() const { return _overhead_words; } 1379 1380 // Adjust local, global counters after a new chunk has been added. 1381 void account_for_new_chunk(const Metachunk* new_chunk); 1382 1383 // Adjust local, global counters after space has been allocated from the current chunk. 1384 void account_for_allocation(size_t words); 1385 1386 // Adjust global counters just before the SpaceManager dies, after all its chunks 1387 // have been returned to the freelist. 1388 void account_for_spacemanager_death(); 1389 1390 // Adjust the initial chunk size to match one of the fixed chunk list sizes, 1391 // or return the unadjusted size if the requested size is humongous. 1392 static size_t adjust_initial_chunk_size(size_t requested, bool is_class_space); 1393 size_t adjust_initial_chunk_size(size_t requested) const; 1394 1395 // Get the initial chunks size for this metaspace type. 1396 size_t get_initial_chunk_size(Metaspace::MetaspaceType type) const; 1397 1398 // Todo: remove this once we have counters by chunk type. 1399 size_t sum_count_in_chunks_in_use(ChunkIndex i); 1400 1401 Metachunk* get_new_chunk(size_t chunk_word_size); 1402 1403 // Block allocation and deallocation. 1404 // Allocates a block from the current chunk 1405 MetaWord* allocate(size_t word_size); 1406 1407 // Helper for allocations 1408 MetaWord* allocate_work(size_t word_size); 1409 1410 // Returns a block to the per manager freelist 1411 void deallocate(MetaWord* p, size_t word_size); 1412 1413 // Based on the allocation size and a minimum chunk size, 1414 // returned chunk size (for expanding space for chunk allocation). 1415 size_t calc_chunk_size(size_t allocation_word_size); 1416 1417 // Called when an allocation from the current chunk fails. 1418 // Gets a new chunk (may require getting a new virtual space), 1419 // and allocates from that chunk. 1420 MetaWord* grow_and_allocate(size_t word_size); 1421 1422 // Notify memory usage to MemoryService. 1423 void track_metaspace_memory_usage(); 1424 1425 // debugging support. 1426 1427 void print_on(outputStream* st) const; 1428 void locked_print_chunks_in_use_on(outputStream* st) const; 1429 1430 void verify(); 1431 void verify_chunk_size(Metachunk* chunk); 1432 1433 // This adjusts the size given to be greater than the minimum allocation size in 1434 // words for data in metaspace. Esentially the minimum size is currently 3 words. 1435 size_t get_allocation_word_size(size_t word_size) { 1436 size_t byte_size = word_size * BytesPerWord; 1437 1438 size_t raw_bytes_size = MAX2(byte_size, sizeof(Metablock)); 1439 raw_bytes_size = align_up(raw_bytes_size, Metachunk::object_alignment()); 1440 1441 size_t raw_word_size = raw_bytes_size / BytesPerWord; 1442 assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem"); 1443 1444 return raw_word_size; 1445 } 1446 1447 // Adds to the given statistic object. 1448 void add_to_statistics(SpaceManagerStatistics* out) const; 1449 1450 // Verify internal counters against the current state. 1451 DEBUG_ONLY(void verify_metrics() const;) 1452 1453 }; 1454 1455 uint const SpaceManager::_small_chunk_limit = 4; 1456 uint const SpaceManager::_anon_and_delegating_metadata_specialize_chunk_limit = 4; 1457 1458 void VirtualSpaceNode::inc_container_count() { 1459 assert_lock_strong(MetaspaceExpand_lock); 1460 _container_count++; 1461 } 1462 1463 void VirtualSpaceNode::dec_container_count() { 1464 assert_lock_strong(MetaspaceExpand_lock); 1465 _container_count--; 1466 } 1467 1468 #ifdef ASSERT 1469 void VirtualSpaceNode::verify_container_count() { 1470 assert(_container_count == container_count_slow(), 1471 "Inconsistency in container_count _container_count " UINTX_FORMAT 1472 " container_count_slow() " UINTX_FORMAT, _container_count, container_count_slow()); 1473 } 1474 #endif 1475 1476 // BlockFreelist methods 1477 1478 BlockFreelist::BlockFreelist() : _dictionary(new BlockTreeDictionary()), _small_blocks(NULL) {} 1479 1480 BlockFreelist::~BlockFreelist() { 1481 delete _dictionary; 1482 if (_small_blocks != NULL) { 1483 delete _small_blocks; 1484 } 1485 } 1486 1487 void BlockFreelist::return_block(MetaWord* p, size_t word_size) { 1488 assert(word_size >= SmallBlocks::small_block_min_size(), "never return dark matter"); 1489 1490 Metablock* free_chunk = ::new (p) Metablock(word_size); 1491 if (word_size < SmallBlocks::small_block_max_size()) { 1492 small_blocks()->return_block(free_chunk, word_size); 1493 } else { 1494 dictionary()->return_chunk(free_chunk); 1495 } 1496 log_trace(gc, metaspace, freelist, blocks)("returning block at " INTPTR_FORMAT " size = " 1497 SIZE_FORMAT, p2i(free_chunk), word_size); 1498 } 1499 1500 MetaWord* BlockFreelist::get_block(size_t word_size) { 1501 assert(word_size >= SmallBlocks::small_block_min_size(), "never get dark matter"); 1502 1503 // Try small_blocks first. 1504 if (word_size < SmallBlocks::small_block_max_size()) { 1505 // Don't create small_blocks() until needed. small_blocks() allocates the small block list for 1506 // this space manager. 1507 MetaWord* new_block = (MetaWord*) small_blocks()->get_block(word_size); 1508 if (new_block != NULL) { 1509 log_trace(gc, metaspace, freelist, blocks)("getting block at " INTPTR_FORMAT " size = " SIZE_FORMAT, 1510 p2i(new_block), word_size); 1511 return new_block; 1512 } 1513 } 1514 1515 if (word_size < BlockFreelist::min_dictionary_size()) { 1516 // If allocation in small blocks fails, this is Dark Matter. Too small for dictionary. 1517 return NULL; 1518 } 1519 1520 Metablock* free_block = dictionary()->get_chunk(word_size); 1521 if (free_block == NULL) { 1522 return NULL; 1523 } 1524 1525 const size_t block_size = free_block->size(); 1526 if (block_size > WasteMultiplier * word_size) { 1527 return_block((MetaWord*)free_block, block_size); 1528 return NULL; 1529 } 1530 1531 MetaWord* new_block = (MetaWord*)free_block; 1532 assert(block_size >= word_size, "Incorrect size of block from freelist"); 1533 const size_t unused = block_size - word_size; 1534 if (unused >= SmallBlocks::small_block_min_size()) { 1535 return_block(new_block + word_size, unused); 1536 } 1537 1538 log_trace(gc, metaspace, freelist, blocks)("getting block at " INTPTR_FORMAT " size = " SIZE_FORMAT, 1539 p2i(new_block), word_size); 1540 return new_block; 1541 } 1542 1543 void BlockFreelist::print_on(outputStream* st) const { 1544 dictionary()->print_free_lists(st); 1545 if (_small_blocks != NULL) { 1546 _small_blocks->print_on(st); 1547 } 1548 } 1549 1550 // VirtualSpaceNode methods 1551 1552 VirtualSpaceNode::~VirtualSpaceNode() { 1553 _rs.release(); 1554 if (_occupancy_map != NULL) { 1555 delete _occupancy_map; 1556 } 1557 #ifdef ASSERT 1558 size_t word_size = sizeof(*this) / BytesPerWord; 1559 Copy::fill_to_words((HeapWord*) this, word_size, 0xf1f1f1f1); 1560 #endif 1561 } 1562 1563 size_t VirtualSpaceNode::used_words_in_vs() const { 1564 return pointer_delta(top(), bottom(), sizeof(MetaWord)); 1565 } 1566 1567 // Space committed in the VirtualSpace 1568 size_t VirtualSpaceNode::capacity_words_in_vs() const { 1569 return pointer_delta(end(), bottom(), sizeof(MetaWord)); 1570 } 1571 1572 size_t VirtualSpaceNode::free_words_in_vs() const { 1573 return pointer_delta(end(), top(), sizeof(MetaWord)); 1574 } 1575 1576 // Given an address larger than top(), allocate padding chunks until top is at the given address. 1577 void VirtualSpaceNode::allocate_padding_chunks_until_top_is_at(MetaWord* target_top) { 1578 1579 assert(target_top > top(), "Sanity"); 1580 1581 // Padding chunks are added to the freelist. 1582 ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(this->is_class()); 1583 1584 // shorthands 1585 const size_t spec_word_size = chunk_manager->specialized_chunk_word_size(); 1586 const size_t small_word_size = chunk_manager->small_chunk_word_size(); 1587 const size_t med_word_size = chunk_manager->medium_chunk_word_size(); 1588 1589 while (top() < target_top) { 1590 1591 // We could make this coding more generic, but right now we only deal with two possible chunk sizes 1592 // for padding chunks, so it is not worth it. 1593 size_t padding_chunk_word_size = small_word_size; 1594 if (is_aligned(top(), small_word_size * sizeof(MetaWord)) == false) { 1595 assert_is_aligned(top(), spec_word_size * sizeof(MetaWord)); // Should always hold true. 1596 padding_chunk_word_size = spec_word_size; 1597 } 1598 MetaWord* here = top(); 1599 assert_is_aligned(here, padding_chunk_word_size * sizeof(MetaWord)); 1600 inc_top(padding_chunk_word_size); 1601 1602 // Create new padding chunk. 1603 ChunkIndex padding_chunk_type = get_chunk_type_by_size(padding_chunk_word_size, is_class()); 1604 assert(padding_chunk_type == SpecializedIndex || padding_chunk_type == SmallIndex, "sanity"); 1605 1606 Metachunk* const padding_chunk = 1607 ::new (here) Metachunk(padding_chunk_type, is_class(), padding_chunk_word_size, this); 1608 assert(padding_chunk == (Metachunk*)here, "Sanity"); 1609 DEBUG_ONLY(padding_chunk->set_origin(origin_pad);) 1610 log_trace(gc, metaspace, freelist)("Created padding chunk in %s at " 1611 PTR_FORMAT ", size " SIZE_FORMAT_HEX ".", 1612 (is_class() ? "class space " : "metaspace"), 1613 p2i(padding_chunk), padding_chunk->word_size() * sizeof(MetaWord)); 1614 1615 // Mark chunk start in occupancy map. 1616 occupancy_map()->set_chunk_starts_at_address((MetaWord*)padding_chunk, true); 1617 1618 // Chunks are born as in-use (see MetaChunk ctor). So, before returning 1619 // the padding chunk to its chunk manager, mark it as in use (ChunkManager 1620 // will assert that). 1621 do_update_in_use_info_for_chunk(padding_chunk, true); 1622 1623 // Return Chunk to freelist. 1624 inc_container_count(); 1625 chunk_manager->return_single_chunk(padding_chunk_type, padding_chunk); 1626 // Please note: at this point, ChunkManager::return_single_chunk() 1627 // may already have merged the padding chunk with neighboring chunks, so 1628 // it may have vanished at this point. Do not reference the padding 1629 // chunk beyond this point. 1630 } 1631 1632 assert(top() == target_top, "Sanity"); 1633 1634 } // allocate_padding_chunks_until_top_is_at() 1635 1636 // Allocates the chunk from the virtual space only. 1637 // This interface is also used internally for debugging. Not all 1638 // chunks removed here are necessarily used for allocation. 1639 Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) { 1640 // Non-humongous chunks are to be allocated aligned to their chunk 1641 // size. So, start addresses of medium chunks are aligned to medium 1642 // chunk size, those of small chunks to small chunk size and so 1643 // forth. This facilitates merging of free chunks and reduces 1644 // fragmentation. Chunk sizes are spec < small < medium, with each 1645 // larger chunk size being a multiple of the next smaller chunk 1646 // size. 1647 // Because of this alignment, me may need to create a number of padding 1648 // chunks. These chunks are created and added to the freelist. 1649 1650 // The chunk manager to which we will give our padding chunks. 1651 ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(this->is_class()); 1652 1653 // shorthands 1654 const size_t spec_word_size = chunk_manager->specialized_chunk_word_size(); 1655 const size_t small_word_size = chunk_manager->small_chunk_word_size(); 1656 const size_t med_word_size = chunk_manager->medium_chunk_word_size(); 1657 1658 assert(chunk_word_size == spec_word_size || chunk_word_size == small_word_size || 1659 chunk_word_size >= med_word_size, "Invalid chunk size requested."); 1660 1661 // Chunk alignment (in bytes) == chunk size unless humongous. 1662 // Humongous chunks are aligned to the smallest chunk size (spec). 1663 const size_t required_chunk_alignment = (chunk_word_size > med_word_size ? 1664 spec_word_size : chunk_word_size) * sizeof(MetaWord); 1665 1666 // Do we have enough space to create the requested chunk plus 1667 // any padding chunks needed? 1668 MetaWord* const next_aligned = 1669 static_cast<MetaWord*>(align_up(top(), required_chunk_alignment)); 1670 if (!is_available((next_aligned - top()) + chunk_word_size)) { 1671 return NULL; 1672 } 1673 1674 // Before allocating the requested chunk, allocate padding chunks if necessary. 1675 // We only need to do this for small or medium chunks: specialized chunks are the 1676 // smallest size, hence always aligned. Homungous chunks are allocated unaligned 1677 // (implicitly, also aligned to smallest chunk size). 1678 if ((chunk_word_size == med_word_size || chunk_word_size == small_word_size) && next_aligned > top()) { 1679 log_trace(gc, metaspace, freelist)("Creating padding chunks in %s between %p and %p...", 1680 (is_class() ? "class space " : "metaspace"), 1681 top(), next_aligned); 1682 allocate_padding_chunks_until_top_is_at(next_aligned); 1683 // Now, top should be aligned correctly. 1684 assert_is_aligned(top(), required_chunk_alignment); 1685 } 1686 1687 // Now, top should be aligned correctly. 1688 assert_is_aligned(top(), required_chunk_alignment); 1689 1690 // Bottom of the new chunk 1691 MetaWord* chunk_limit = top(); 1692 assert(chunk_limit != NULL, "Not safe to call this method"); 1693 1694 // The virtual spaces are always expanded by the 1695 // commit granularity to enforce the following condition. 1696 // Without this the is_available check will not work correctly. 1697 assert(_virtual_space.committed_size() == _virtual_space.actual_committed_size(), 1698 "The committed memory doesn't match the expanded memory."); 1699 1700 if (!is_available(chunk_word_size)) { 1701 LogTarget(Debug, gc, metaspace, freelist) lt; 1702 if (lt.is_enabled()) { 1703 LogStream ls(lt); 1704 ls.print("VirtualSpaceNode::take_from_committed() not available " SIZE_FORMAT " words ", chunk_word_size); 1705 // Dump some information about the virtual space that is nearly full 1706 print_on(&ls); 1707 ls.cr(); // ~LogStream does not autoflush. 1708 } 1709 return NULL; 1710 } 1711 1712 // Take the space (bump top on the current virtual space). 1713 inc_top(chunk_word_size); 1714 1715 // Initialize the chunk 1716 ChunkIndex chunk_type = get_chunk_type_by_size(chunk_word_size, is_class()); 1717 Metachunk* result = ::new (chunk_limit) Metachunk(chunk_type, is_class(), chunk_word_size, this); 1718 assert(result == (Metachunk*)chunk_limit, "Sanity"); 1719 occupancy_map()->set_chunk_starts_at_address((MetaWord*)result, true); 1720 do_update_in_use_info_for_chunk(result, true); 1721 1722 inc_container_count(); 1723 1724 if (VerifyMetaspace) { 1725 DEBUG_ONLY(chunk_manager->locked_verify()); 1726 DEBUG_ONLY(this->verify()); 1727 } 1728 1729 DEBUG_ONLY(do_verify_chunk(result)); 1730 1731 result->inc_use_count(); 1732 1733 return result; 1734 } 1735 1736 1737 // Expand the virtual space (commit more of the reserved space) 1738 bool VirtualSpaceNode::expand_by(size_t min_words, size_t preferred_words) { 1739 size_t min_bytes = min_words * BytesPerWord; 1740 size_t preferred_bytes = preferred_words * BytesPerWord; 1741 1742 size_t uncommitted = virtual_space()->reserved_size() - virtual_space()->actual_committed_size(); 1743 1744 if (uncommitted < min_bytes) { 1745 return false; 1746 } 1747 1748 size_t commit = MIN2(preferred_bytes, uncommitted); 1749 bool result = virtual_space()->expand_by(commit, false); 1750 1751 if (result) { 1752 log_trace(gc, metaspace, freelist)("Expanded %s virtual space list node by " SIZE_FORMAT " words.", 1753 (is_class() ? "class" : "non-class"), commit); 1754 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_committed_space_expanded)); 1755 } else { 1756 log_trace(gc, metaspace, freelist)("Failed to expand %s virtual space list node by " SIZE_FORMAT " words.", 1757 (is_class() ? "class" : "non-class"), commit); 1758 } 1759 1760 assert(result, "Failed to commit memory"); 1761 1762 return result; 1763 } 1764 1765 Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) { 1766 assert_lock_strong(MetaspaceExpand_lock); 1767 Metachunk* result = take_from_committed(chunk_word_size); 1768 return result; 1769 } 1770 1771 bool VirtualSpaceNode::initialize() { 1772 1773 if (!_rs.is_reserved()) { 1774 return false; 1775 } 1776 1777 // These are necessary restriction to make sure that the virtual space always 1778 // grows in steps of Metaspace::commit_alignment(). If both base and size are 1779 // aligned only the middle alignment of the VirtualSpace is used. 1780 assert_is_aligned(_rs.base(), Metaspace::commit_alignment()); 1781 assert_is_aligned(_rs.size(), Metaspace::commit_alignment()); 1782 1783 // ReservedSpaces marked as special will have the entire memory 1784 // pre-committed. Setting a committed size will make sure that 1785 // committed_size and actual_committed_size agrees. 1786 size_t pre_committed_size = _rs.special() ? _rs.size() : 0; 1787 1788 bool result = virtual_space()->initialize_with_granularity(_rs, pre_committed_size, 1789 Metaspace::commit_alignment()); 1790 if (result) { 1791 assert(virtual_space()->committed_size() == virtual_space()->actual_committed_size(), 1792 "Checking that the pre-committed memory was registered by the VirtualSpace"); 1793 1794 set_top((MetaWord*)virtual_space()->low()); 1795 set_reserved(MemRegion((HeapWord*)_rs.base(), 1796 (HeapWord*)(_rs.base() + _rs.size()))); 1797 1798 assert(reserved()->start() == (HeapWord*) _rs.base(), 1799 "Reserved start was not set properly " PTR_FORMAT 1800 " != " PTR_FORMAT, p2i(reserved()->start()), p2i(_rs.base())); 1801 assert(reserved()->word_size() == _rs.size() / BytesPerWord, 1802 "Reserved size was not set properly " SIZE_FORMAT 1803 " != " SIZE_FORMAT, reserved()->word_size(), 1804 _rs.size() / BytesPerWord); 1805 } 1806 1807 // Initialize Occupancy Map. 1808 const size_t smallest_chunk_size = is_class() ? ClassSpecializedChunk : SpecializedChunk; 1809 _occupancy_map = new OccupancyMap(bottom(), reserved_words(), smallest_chunk_size); 1810 1811 return result; 1812 } 1813 1814 void VirtualSpaceNode::print_on(outputStream* st, size_t scale) const { 1815 size_t used_words = used_words_in_vs(); 1816 size_t commit_words = committed_words(); 1817 size_t res_words = reserved_words(); 1818 VirtualSpace* vs = virtual_space(); 1819 1820 st->print("node @" PTR_FORMAT ": ", p2i(this)); 1821 st->print("reserved="); 1822 print_scaled_words(st, res_words, scale); 1823 st->print(", committed="); 1824 print_scaled_words_and_percentage(st, commit_words, res_words, scale); 1825 st->print(", used="); 1826 print_scaled_words_and_percentage(st, used_words, res_words, scale); 1827 st->cr(); 1828 st->print(" [" PTR_FORMAT ", " PTR_FORMAT ", " 1829 PTR_FORMAT ", " PTR_FORMAT ")", 1830 p2i(bottom()), p2i(top()), p2i(end()), 1831 p2i(vs->high_boundary())); 1832 } 1833 1834 #ifdef ASSERT 1835 void VirtualSpaceNode::mangle() { 1836 size_t word_size = capacity_words_in_vs(); 1837 Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1); 1838 } 1839 #endif // ASSERT 1840 1841 // VirtualSpaceList methods 1842 // Space allocated from the VirtualSpace 1843 1844 VirtualSpaceList::~VirtualSpaceList() { 1845 VirtualSpaceListIterator iter(virtual_space_list()); 1846 while (iter.repeat()) { 1847 VirtualSpaceNode* vsl = iter.get_next(); 1848 delete vsl; 1849 } 1850 } 1851 1852 void VirtualSpaceList::inc_reserved_words(size_t v) { 1853 assert_lock_strong(MetaspaceExpand_lock); 1854 _reserved_words = _reserved_words + v; 1855 } 1856 void VirtualSpaceList::dec_reserved_words(size_t v) { 1857 assert_lock_strong(MetaspaceExpand_lock); 1858 _reserved_words = _reserved_words - v; 1859 } 1860 1861 #define assert_committed_below_limit() \ 1862 assert(MetaspaceUtils::committed_bytes() <= MaxMetaspaceSize, \ 1863 "Too much committed memory. Committed: " SIZE_FORMAT \ 1864 " limit (MaxMetaspaceSize): " SIZE_FORMAT, \ 1865 MetaspaceUtils::committed_bytes(), MaxMetaspaceSize); 1866 1867 void VirtualSpaceList::inc_committed_words(size_t v) { 1868 assert_lock_strong(MetaspaceExpand_lock); 1869 _committed_words = _committed_words + v; 1870 1871 assert_committed_below_limit(); 1872 } 1873 void VirtualSpaceList::dec_committed_words(size_t v) { 1874 assert_lock_strong(MetaspaceExpand_lock); 1875 _committed_words = _committed_words - v; 1876 1877 assert_committed_below_limit(); 1878 } 1879 1880 void VirtualSpaceList::inc_virtual_space_count() { 1881 assert_lock_strong(MetaspaceExpand_lock); 1882 _virtual_space_count++; 1883 } 1884 void VirtualSpaceList::dec_virtual_space_count() { 1885 assert_lock_strong(MetaspaceExpand_lock); 1886 _virtual_space_count--; 1887 } 1888 1889 void ChunkManager::remove_chunk(Metachunk* chunk) { 1890 size_t word_size = chunk->word_size(); 1891 ChunkIndex index = list_index(word_size); 1892 if (index != HumongousIndex) { 1893 free_chunks(index)->remove_chunk(chunk); 1894 } else { 1895 humongous_dictionary()->remove_chunk(chunk); 1896 } 1897 1898 // Chunk has been removed from the chunks free list, update counters. 1899 account_for_removed_chunk(chunk); 1900 } 1901 1902 bool ChunkManager::attempt_to_coalesce_around_chunk(Metachunk* chunk, ChunkIndex target_chunk_type) { 1903 assert_lock_strong(MetaspaceExpand_lock); 1904 assert(chunk != NULL, "invalid chunk pointer"); 1905 // Check for valid merge combinations. 1906 assert((chunk->get_chunk_type() == SpecializedIndex && 1907 (target_chunk_type == SmallIndex || target_chunk_type == MediumIndex)) || 1908 (chunk->get_chunk_type() == SmallIndex && target_chunk_type == MediumIndex), 1909 "Invalid chunk merge combination."); 1910 1911 const size_t target_chunk_word_size = 1912 get_size_for_nonhumongous_chunktype(target_chunk_type, this->is_class()); 1913 1914 // [ prospective merge region ) 1915 MetaWord* const p_merge_region_start = 1916 (MetaWord*) align_down(chunk, target_chunk_word_size * sizeof(MetaWord)); 1917 MetaWord* const p_merge_region_end = 1918 p_merge_region_start + target_chunk_word_size; 1919 1920 // We need the VirtualSpaceNode containing this chunk and its occupancy map. 1921 VirtualSpaceNode* const vsn = chunk->container(); 1922 OccupancyMap* const ocmap = vsn->occupancy_map(); 1923 1924 // The prospective chunk merge range must be completely contained by the 1925 // committed range of the virtual space node. 1926 if (p_merge_region_start < vsn->bottom() || p_merge_region_end > vsn->top()) { 1927 return false; 1928 } 1929 1930 // Only attempt to merge this range if at its start a chunk starts and at its end 1931 // a chunk ends. If a chunk (can only be humongous) straddles either start or end 1932 // of that range, we cannot merge. 1933 if (!ocmap->chunk_starts_at_address(p_merge_region_start)) { 1934 return false; 1935 } 1936 if (p_merge_region_end < vsn->top() && 1937 !ocmap->chunk_starts_at_address(p_merge_region_end)) { 1938 return false; 1939 } 1940 1941 // Now check if the prospective merge area contains live chunks. If it does we cannot merge. 1942 if (ocmap->is_region_in_use(p_merge_region_start, target_chunk_word_size)) { 1943 return false; 1944 } 1945 1946 // Success! Remove all chunks in this region... 1947 log_trace(gc, metaspace, freelist)("%s: coalescing chunks in area [%p-%p)...", 1948 (is_class() ? "class space" : "metaspace"), 1949 p_merge_region_start, p_merge_region_end); 1950 1951 const int num_chunks_removed = 1952 remove_chunks_in_area(p_merge_region_start, target_chunk_word_size); 1953 1954 // ... and create a single new bigger chunk. 1955 Metachunk* const p_new_chunk = 1956 ::new (p_merge_region_start) Metachunk(target_chunk_type, is_class(), target_chunk_word_size, vsn); 1957 assert(p_new_chunk == (Metachunk*)p_merge_region_start, "Sanity"); 1958 p_new_chunk->set_origin(origin_merge); 1959 1960 log_trace(gc, metaspace, freelist)("%s: created coalesced chunk at %p, size " SIZE_FORMAT_HEX ".", 1961 (is_class() ? "class space" : "metaspace"), 1962 p_new_chunk, p_new_chunk->word_size() * sizeof(MetaWord)); 1963 1964 // Fix occupancy map: remove old start bits of the small chunks and set new start bit. 1965 ocmap->wipe_chunk_start_bits_in_region(p_merge_region_start, target_chunk_word_size); 1966 ocmap->set_chunk_starts_at_address(p_merge_region_start, true); 1967 1968 // Mark chunk as free. Note: it is not necessary to update the occupancy 1969 // map in-use map, because the old chunks were also free, so nothing 1970 // should have changed. 1971 p_new_chunk->set_is_tagged_free(true); 1972 1973 // Add new chunk to its freelist. 1974 ChunkList* const list = free_chunks(target_chunk_type); 1975 list->return_chunk_at_head(p_new_chunk); 1976 1977 // And adjust ChunkManager:: _free_chunks_count (_free_chunks_total 1978 // should not have changed, because the size of the space should be the same) 1979 _free_chunks_count -= num_chunks_removed; 1980 _free_chunks_count ++; 1981 1982 // VirtualSpaceNode::container_count does not have to be modified: 1983 // it means "number of active (non-free) chunks", so merging free chunks 1984 // should not affect that count. 1985 1986 // At the end of a chunk merge, run verification tests. 1987 if (VerifyMetaspace) { 1988 DEBUG_ONLY(this->locked_verify()); 1989 DEBUG_ONLY(vsn->verify()); 1990 } 1991 1992 return true; 1993 } 1994 1995 // Remove all chunks in the given area - the chunks are supposed to be free - 1996 // from their corresponding freelists. Mark them as invalid. 1997 // - This does not correct the occupancy map. 1998 // - This does not adjust the counters in ChunkManager. 1999 // - Does not adjust container count counter in containing VirtualSpaceNode 2000 // Returns number of chunks removed. 2001 int ChunkManager::remove_chunks_in_area(MetaWord* p, size_t word_size) { 2002 assert(p != NULL && word_size > 0, "Invalid range."); 2003 const size_t smallest_chunk_size = get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class()); 2004 assert_is_aligned(word_size, smallest_chunk_size); 2005 2006 Metachunk* const start = (Metachunk*) p; 2007 const Metachunk* const end = (Metachunk*)(p + word_size); 2008 Metachunk* cur = start; 2009 int num_removed = 0; 2010 while (cur < end) { 2011 Metachunk* next = (Metachunk*)(((MetaWord*)cur) + cur->word_size()); 2012 DEBUG_ONLY(do_verify_chunk(cur)); 2013 assert(cur->get_chunk_type() != HumongousIndex, "Unexpected humongous chunk found at %p.", cur); 2014 assert(cur->is_tagged_free(), "Chunk expected to be free (%p)", cur); 2015 log_trace(gc, metaspace, freelist)("%s: removing chunk %p, size " SIZE_FORMAT_HEX ".", 2016 (is_class() ? "class space" : "metaspace"), 2017 cur, cur->word_size() * sizeof(MetaWord)); 2018 cur->remove_sentinel(); 2019 // Note: cannot call ChunkManager::remove_chunk, because that 2020 // modifies the counters in ChunkManager, which we do not want. So 2021 // we call remove_chunk on the freelist directly (see also the 2022 // splitting function which does the same). 2023 ChunkList* const list = free_chunks(list_index(cur->word_size())); 2024 list->remove_chunk(cur); 2025 num_removed ++; 2026 cur = next; 2027 } 2028 return num_removed; 2029 } 2030 2031 // Walk the list of VirtualSpaceNodes and delete 2032 // nodes with a 0 container_count. Remove Metachunks in 2033 // the node from their respective freelists. 2034 void VirtualSpaceList::purge(ChunkManager* chunk_manager) { 2035 assert(SafepointSynchronize::is_at_safepoint(), "must be called at safepoint for contains to work"); 2036 assert_lock_strong(MetaspaceExpand_lock); 2037 // Don't use a VirtualSpaceListIterator because this 2038 // list is being changed and a straightforward use of an iterator is not safe. 2039 VirtualSpaceNode* purged_vsl = NULL; 2040 VirtualSpaceNode* prev_vsl = virtual_space_list(); 2041 VirtualSpaceNode* next_vsl = prev_vsl; 2042 while (next_vsl != NULL) { 2043 VirtualSpaceNode* vsl = next_vsl; 2044 DEBUG_ONLY(vsl->verify_container_count();) 2045 next_vsl = vsl->next(); 2046 // Don't free the current virtual space since it will likely 2047 // be needed soon. 2048 if (vsl->container_count() == 0 && vsl != current_virtual_space()) { 2049 log_trace(gc, metaspace, freelist)("Purging VirtualSpaceNode " PTR_FORMAT " (capacity: " SIZE_FORMAT 2050 ", used: " SIZE_FORMAT ").", p2i(vsl), vsl->capacity_words_in_vs(), vsl->used_words_in_vs()); 2051 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_vsnodes_purged)); 2052 // Unlink it from the list 2053 if (prev_vsl == vsl) { 2054 // This is the case of the current node being the first node. 2055 assert(vsl == virtual_space_list(), "Expected to be the first node"); 2056 set_virtual_space_list(vsl->next()); 2057 } else { 2058 prev_vsl->set_next(vsl->next()); 2059 } 2060 2061 vsl->purge(chunk_manager); 2062 dec_reserved_words(vsl->reserved_words()); 2063 dec_committed_words(vsl->committed_words()); 2064 dec_virtual_space_count(); 2065 purged_vsl = vsl; 2066 delete vsl; 2067 } else { 2068 prev_vsl = vsl; 2069 } 2070 } 2071 #ifdef ASSERT 2072 if (purged_vsl != NULL) { 2073 // List should be stable enough to use an iterator here. 2074 VirtualSpaceListIterator iter(virtual_space_list()); 2075 while (iter.repeat()) { 2076 VirtualSpaceNode* vsl = iter.get_next(); 2077 assert(vsl != purged_vsl, "Purge of vsl failed"); 2078 } 2079 } 2080 #endif 2081 } 2082 2083 2084 // This function looks at the mmap regions in the metaspace without locking. 2085 // The chunks are added with store ordering and not deleted except for at 2086 // unloading time during a safepoint. 2087 bool VirtualSpaceList::contains(const void* ptr) { 2088 // List should be stable enough to use an iterator here because removing virtual 2089 // space nodes is only allowed at a safepoint. 2090 VirtualSpaceListIterator iter(virtual_space_list()); 2091 while (iter.repeat()) { 2092 VirtualSpaceNode* vsn = iter.get_next(); 2093 if (vsn->contains(ptr)) { 2094 return true; 2095 } 2096 } 2097 return false; 2098 } 2099 2100 void VirtualSpaceList::retire_current_virtual_space() { 2101 assert_lock_strong(MetaspaceExpand_lock); 2102 2103 VirtualSpaceNode* vsn = current_virtual_space(); 2104 2105 ChunkManager* cm = is_class() ? Metaspace::chunk_manager_class() : 2106 Metaspace::chunk_manager_metadata(); 2107 2108 vsn->retire(cm); 2109 } 2110 2111 void VirtualSpaceNode::retire(ChunkManager* chunk_manager) { 2112 DEBUG_ONLY(verify_container_count();) 2113 assert(this->is_class() == chunk_manager->is_class(), "Wrong ChunkManager?"); 2114 for (int i = (int)MediumIndex; i >= (int)ZeroIndex; --i) { 2115 ChunkIndex index = (ChunkIndex)i; 2116 size_t chunk_size = chunk_manager->size_by_index(index); 2117 2118 while (free_words_in_vs() >= chunk_size) { 2119 Metachunk* chunk = get_chunk_vs(chunk_size); 2120 // Chunk will be allocated aligned, so allocation may require 2121 // additional padding chunks. That may cause above allocation to 2122 // fail. Just ignore the failed allocation and continue with the 2123 // next smaller chunk size. As the VirtualSpaceNode comitted 2124 // size should be a multiple of the smallest chunk size, we 2125 // should always be able to fill the VirtualSpace completely. 2126 if (chunk == NULL) { 2127 break; 2128 } 2129 chunk_manager->return_single_chunk(index, chunk); 2130 } 2131 DEBUG_ONLY(verify_container_count();) 2132 } 2133 assert(free_words_in_vs() == 0, "should be empty now"); 2134 } 2135 2136 VirtualSpaceList::VirtualSpaceList(size_t word_size) : 2137 _is_class(false), 2138 _virtual_space_list(NULL), 2139 _current_virtual_space(NULL), 2140 _reserved_words(0), 2141 _committed_words(0), 2142 _virtual_space_count(0) { 2143 MutexLockerEx cl(MetaspaceExpand_lock, 2144 Mutex::_no_safepoint_check_flag); 2145 create_new_virtual_space(word_size); 2146 } 2147 2148 VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) : 2149 _is_class(true), 2150 _virtual_space_list(NULL), 2151 _current_virtual_space(NULL), 2152 _reserved_words(0), 2153 _committed_words(0), 2154 _virtual_space_count(0) { 2155 MutexLockerEx cl(MetaspaceExpand_lock, 2156 Mutex::_no_safepoint_check_flag); 2157 VirtualSpaceNode* class_entry = new VirtualSpaceNode(is_class(), rs); 2158 bool succeeded = class_entry->initialize(); 2159 if (succeeded) { 2160 link_vs(class_entry); 2161 } 2162 } 2163 2164 size_t VirtualSpaceList::free_bytes() { 2165 return current_virtual_space()->free_words_in_vs() * BytesPerWord; 2166 } 2167 2168 // Allocate another meta virtual space and add it to the list. 2169 bool VirtualSpaceList::create_new_virtual_space(size_t vs_word_size) { 2170 assert_lock_strong(MetaspaceExpand_lock); 2171 2172 if (is_class()) { 2173 assert(false, "We currently don't support more than one VirtualSpace for" 2174 " the compressed class space. The initialization of the" 2175 " CCS uses another code path and should not hit this path."); 2176 return false; 2177 } 2178 2179 if (vs_word_size == 0) { 2180 assert(false, "vs_word_size should always be at least _reserve_alignment large."); 2181 return false; 2182 } 2183 2184 // Reserve the space 2185 size_t vs_byte_size = vs_word_size * BytesPerWord; 2186 assert_is_aligned(vs_byte_size, Metaspace::reserve_alignment()); 2187 2188 // Allocate the meta virtual space and initialize it. 2189 VirtualSpaceNode* new_entry = new VirtualSpaceNode(is_class(), vs_byte_size); 2190 if (!new_entry->initialize()) { 2191 delete new_entry; 2192 return false; 2193 } else { 2194 assert(new_entry->reserved_words() == vs_word_size, 2195 "Reserved memory size differs from requested memory size"); 2196 // ensure lock-free iteration sees fully initialized node 2197 OrderAccess::storestore(); 2198 link_vs(new_entry); 2199 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_vsnodes_created)); 2200 return true; 2201 } 2202 } 2203 2204 void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry) { 2205 if (virtual_space_list() == NULL) { 2206 set_virtual_space_list(new_entry); 2207 } else { 2208 current_virtual_space()->set_next(new_entry); 2209 } 2210 set_current_virtual_space(new_entry); 2211 inc_reserved_words(new_entry->reserved_words()); 2212 inc_committed_words(new_entry->committed_words()); 2213 inc_virtual_space_count(); 2214 #ifdef ASSERT 2215 new_entry->mangle(); 2216 #endif 2217 LogTarget(Trace, gc, metaspace) lt; 2218 if (lt.is_enabled()) { 2219 LogStream ls(lt); 2220 VirtualSpaceNode* vsl = current_virtual_space(); 2221 ResourceMark rm; 2222 vsl->print_on(&ls); 2223 ls.cr(); // ~LogStream does not autoflush. 2224 } 2225 } 2226 2227 bool VirtualSpaceList::expand_node_by(VirtualSpaceNode* node, 2228 size_t min_words, 2229 size_t preferred_words) { 2230 size_t before = node->committed_words(); 2231 2232 bool result = node->expand_by(min_words, preferred_words); 2233 2234 size_t after = node->committed_words(); 2235 2236 // after and before can be the same if the memory was pre-committed. 2237 assert(after >= before, "Inconsistency"); 2238 inc_committed_words(after - before); 2239 2240 return result; 2241 } 2242 2243 bool VirtualSpaceList::expand_by(size_t min_words, size_t preferred_words) { 2244 assert_is_aligned(min_words, Metaspace::commit_alignment_words()); 2245 assert_is_aligned(preferred_words, Metaspace::commit_alignment_words()); 2246 assert(min_words <= preferred_words, "Invalid arguments"); 2247 2248 const char* const class_or_not = (is_class() ? "class" : "non-class"); 2249 2250 if (!MetaspaceGC::can_expand(min_words, this->is_class())) { 2251 log_trace(gc, metaspace, freelist)("Cannot expand %s virtual space list.", 2252 class_or_not); 2253 return false; 2254 } 2255 2256 size_t allowed_expansion_words = MetaspaceGC::allowed_expansion(); 2257 if (allowed_expansion_words < min_words) { 2258 log_trace(gc, metaspace, freelist)("Cannot expand %s virtual space list (must try gc first).", 2259 class_or_not); 2260 return false; 2261 } 2262 2263 size_t max_expansion_words = MIN2(preferred_words, allowed_expansion_words); 2264 2265 // Commit more memory from the the current virtual space. 2266 bool vs_expanded = expand_node_by(current_virtual_space(), 2267 min_words, 2268 max_expansion_words); 2269 if (vs_expanded) { 2270 log_trace(gc, metaspace, freelist)("Expanded %s virtual space list.", 2271 class_or_not); 2272 return true; 2273 } 2274 log_trace(gc, metaspace, freelist)("%s virtual space list: retire current node.", 2275 class_or_not); 2276 retire_current_virtual_space(); 2277 2278 // Get another virtual space. 2279 size_t grow_vs_words = MAX2((size_t)VirtualSpaceSize, preferred_words); 2280 grow_vs_words = align_up(grow_vs_words, Metaspace::reserve_alignment_words()); 2281 2282 if (create_new_virtual_space(grow_vs_words)) { 2283 if (current_virtual_space()->is_pre_committed()) { 2284 // The memory was pre-committed, so we are done here. 2285 assert(min_words <= current_virtual_space()->committed_words(), 2286 "The new VirtualSpace was pre-committed, so it" 2287 "should be large enough to fit the alloc request."); 2288 return true; 2289 } 2290 2291 return expand_node_by(current_virtual_space(), 2292 min_words, 2293 max_expansion_words); 2294 } 2295 2296 return false; 2297 } 2298 2299 // Given a chunk, calculate the largest possible padding space which 2300 // could be required when allocating it. 2301 static size_t largest_possible_padding_size_for_chunk(size_t chunk_word_size, bool is_class) { 2302 const ChunkIndex chunk_type = get_chunk_type_by_size(chunk_word_size, is_class); 2303 if (chunk_type != HumongousIndex) { 2304 // Normal, non-humongous chunks are allocated at chunk size 2305 // boundaries, so the largest padding space required would be that 2306 // minus the smallest chunk size. 2307 const size_t smallest_chunk_size = is_class ? ClassSpecializedChunk : SpecializedChunk; 2308 return chunk_word_size - smallest_chunk_size; 2309 } else { 2310 // Humongous chunks are allocated at smallest-chunksize 2311 // boundaries, so there is no padding required. 2312 return 0; 2313 } 2314 } 2315 2316 2317 Metachunk* VirtualSpaceList::get_new_chunk(size_t chunk_word_size, size_t suggested_commit_granularity) { 2318 2319 // Allocate a chunk out of the current virtual space. 2320 Metachunk* next = current_virtual_space()->get_chunk_vs(chunk_word_size); 2321 2322 if (next != NULL) { 2323 return next; 2324 } 2325 2326 // The expand amount is currently only determined by the requested sizes 2327 // and not how much committed memory is left in the current virtual space. 2328 2329 // We must have enough space for the requested size and any 2330 // additional reqired padding chunks. 2331 const size_t size_for_padding = largest_possible_padding_size_for_chunk(chunk_word_size, this->is_class()); 2332 2333 size_t min_word_size = align_up(chunk_word_size + size_for_padding, Metaspace::commit_alignment_words()); 2334 size_t preferred_word_size = align_up(suggested_commit_granularity, Metaspace::commit_alignment_words()); 2335 if (min_word_size >= preferred_word_size) { 2336 // Can happen when humongous chunks are allocated. 2337 preferred_word_size = min_word_size; 2338 } 2339 2340 bool expanded = expand_by(min_word_size, preferred_word_size); 2341 if (expanded) { 2342 next = current_virtual_space()->get_chunk_vs(chunk_word_size); 2343 assert(next != NULL, "The allocation was expected to succeed after the expansion"); 2344 } 2345 2346 return next; 2347 } 2348 2349 void VirtualSpaceList::print_on(outputStream* st, size_t scale) const { 2350 st->print_cr(SIZE_FORMAT " nodes, current node: " PTR_FORMAT, 2351 _virtual_space_count, p2i(_current_virtual_space)); 2352 VirtualSpaceListIterator iter(virtual_space_list()); 2353 while (iter.repeat()) { 2354 st->cr(); 2355 VirtualSpaceNode* node = iter.get_next(); 2356 node->print_on(st, scale); 2357 } 2358 } 2359 2360 void VirtualSpaceList::print_map(outputStream* st) const { 2361 VirtualSpaceNode* list = virtual_space_list(); 2362 VirtualSpaceListIterator iter(list); 2363 unsigned i = 0; 2364 while (iter.repeat()) { 2365 st->print_cr("Node %u:", i); 2366 VirtualSpaceNode* node = iter.get_next(); 2367 node->print_map(st, this->is_class()); 2368 i ++; 2369 } 2370 } 2371 2372 // MetaspaceGC methods 2373 2374 // VM_CollectForMetadataAllocation is the vm operation used to GC. 2375 // Within the VM operation after the GC the attempt to allocate the metadata 2376 // should succeed. If the GC did not free enough space for the metaspace 2377 // allocation, the HWM is increased so that another virtualspace will be 2378 // allocated for the metadata. With perm gen the increase in the perm 2379 // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion. The 2380 // metaspace policy uses those as the small and large steps for the HWM. 2381 // 2382 // After the GC the compute_new_size() for MetaspaceGC is called to 2383 // resize the capacity of the metaspaces. The current implementation 2384 // is based on the flags MinMetaspaceFreeRatio and MaxMetaspaceFreeRatio used 2385 // to resize the Java heap by some GC's. New flags can be implemented 2386 // if really needed. MinMetaspaceFreeRatio is used to calculate how much 2387 // free space is desirable in the metaspace capacity to decide how much 2388 // to increase the HWM. MaxMetaspaceFreeRatio is used to decide how much 2389 // free space is desirable in the metaspace capacity before decreasing 2390 // the HWM. 2391 2392 // Calculate the amount to increase the high water mark (HWM). 2393 // Increase by a minimum amount (MinMetaspaceExpansion) so that 2394 // another expansion is not requested too soon. If that is not 2395 // enough to satisfy the allocation, increase by MaxMetaspaceExpansion. 2396 // If that is still not enough, expand by the size of the allocation 2397 // plus some. 2398 size_t MetaspaceGC::delta_capacity_until_GC(size_t bytes) { 2399 size_t min_delta = MinMetaspaceExpansion; 2400 size_t max_delta = MaxMetaspaceExpansion; 2401 size_t delta = align_up(bytes, Metaspace::commit_alignment()); 2402 2403 if (delta <= min_delta) { 2404 delta = min_delta; 2405 } else if (delta <= max_delta) { 2406 // Don't want to hit the high water mark on the next 2407 // allocation so make the delta greater than just enough 2408 // for this allocation. 2409 delta = max_delta; 2410 } else { 2411 // This allocation is large but the next ones are probably not 2412 // so increase by the minimum. 2413 delta = delta + min_delta; 2414 } 2415 2416 assert_is_aligned(delta, Metaspace::commit_alignment()); 2417 2418 return delta; 2419 } 2420 2421 size_t MetaspaceGC::capacity_until_GC() { 2422 size_t value = OrderAccess::load_acquire(&_capacity_until_GC); 2423 assert(value >= MetaspaceSize, "Not initialized properly?"); 2424 return value; 2425 } 2426 2427 bool MetaspaceGC::inc_capacity_until_GC(size_t v, size_t* new_cap_until_GC, size_t* old_cap_until_GC) { 2428 assert_is_aligned(v, Metaspace::commit_alignment()); 2429 2430 intptr_t capacity_until_GC = _capacity_until_GC; 2431 intptr_t new_value = capacity_until_GC + v; 2432 2433 if (new_value < capacity_until_GC) { 2434 // The addition wrapped around, set new_value to aligned max value. 2435 new_value = align_down(max_uintx, Metaspace::commit_alignment()); 2436 } 2437 2438 intptr_t expected = _capacity_until_GC; 2439 intptr_t actual = Atomic::cmpxchg(new_value, &_capacity_until_GC, expected); 2440 2441 if (expected != actual) { 2442 return false; 2443 } 2444 2445 if (new_cap_until_GC != NULL) { 2446 *new_cap_until_GC = new_value; 2447 } 2448 if (old_cap_until_GC != NULL) { 2449 *old_cap_until_GC = capacity_until_GC; 2450 } 2451 return true; 2452 } 2453 2454 size_t MetaspaceGC::dec_capacity_until_GC(size_t v) { 2455 assert_is_aligned(v, Metaspace::commit_alignment()); 2456 2457 return (size_t)Atomic::sub((intptr_t)v, &_capacity_until_GC); 2458 } 2459 2460 void MetaspaceGC::initialize() { 2461 // Set the high-water mark to MaxMetapaceSize during VM initializaton since 2462 // we can't do a GC during initialization. 2463 _capacity_until_GC = MaxMetaspaceSize; 2464 } 2465 2466 void MetaspaceGC::post_initialize() { 2467 // Reset the high-water mark once the VM initialization is done. 2468 _capacity_until_GC = MAX2(MetaspaceUtils::committed_bytes(), MetaspaceSize); 2469 } 2470 2471 bool MetaspaceGC::can_expand(size_t word_size, bool is_class) { 2472 // Check if the compressed class space is full. 2473 if (is_class && Metaspace::using_class_space()) { 2474 size_t class_committed = MetaspaceUtils::committed_bytes(Metaspace::ClassType); 2475 if (class_committed + word_size * BytesPerWord > CompressedClassSpaceSize) { 2476 log_trace(gc, metaspace, freelist)("Cannot expand %s metaspace by " SIZE_FORMAT " words (CompressedClassSpaceSize = " SIZE_FORMAT " words)", 2477 (is_class ? "class" : "non-class"), word_size, CompressedClassSpaceSize / sizeof(MetaWord)); 2478 return false; 2479 } 2480 } 2481 2482 // Check if the user has imposed a limit on the metaspace memory. 2483 size_t committed_bytes = MetaspaceUtils::committed_bytes(); 2484 if (committed_bytes + word_size * BytesPerWord > MaxMetaspaceSize) { 2485 log_trace(gc, metaspace, freelist)("Cannot expand %s metaspace by " SIZE_FORMAT " words (MaxMetaspaceSize = " SIZE_FORMAT " words)", 2486 (is_class ? "class" : "non-class"), word_size, MaxMetaspaceSize / sizeof(MetaWord)); 2487 return false; 2488 } 2489 2490 return true; 2491 } 2492 2493 size_t MetaspaceGC::allowed_expansion() { 2494 size_t committed_bytes = MetaspaceUtils::committed_bytes(); 2495 size_t capacity_until_gc = capacity_until_GC(); 2496 2497 assert(capacity_until_gc >= committed_bytes, 2498 "capacity_until_gc: " SIZE_FORMAT " < committed_bytes: " SIZE_FORMAT, 2499 capacity_until_gc, committed_bytes); 2500 2501 size_t left_until_max = MaxMetaspaceSize - committed_bytes; 2502 size_t left_until_GC = capacity_until_gc - committed_bytes; 2503 size_t left_to_commit = MIN2(left_until_GC, left_until_max); 2504 log_trace(gc, metaspace, freelist)("allowed expansion words: " SIZE_FORMAT 2505 " (left_until_max: " SIZE_FORMAT ", left_until_GC: " SIZE_FORMAT ".", 2506 left_to_commit / BytesPerWord, left_until_max / BytesPerWord, left_until_GC / BytesPerWord); 2507 2508 return left_to_commit / BytesPerWord; 2509 } 2510 2511 void MetaspaceGC::compute_new_size() { 2512 assert(_shrink_factor <= 100, "invalid shrink factor"); 2513 uint current_shrink_factor = _shrink_factor; 2514 _shrink_factor = 0; 2515 2516 // Using committed_bytes() for used_after_gc is an overestimation, since the 2517 // chunk free lists are included in committed_bytes() and the memory in an 2518 // un-fragmented chunk free list is available for future allocations. 2519 // However, if the chunk free lists becomes fragmented, then the memory may 2520 // not be available for future allocations and the memory is therefore "in use". 2521 // Including the chunk free lists in the definition of "in use" is therefore 2522 // necessary. Not including the chunk free lists can cause capacity_until_GC to 2523 // shrink below committed_bytes() and this has caused serious bugs in the past. 2524 const size_t used_after_gc = MetaspaceUtils::committed_bytes(); 2525 const size_t capacity_until_GC = MetaspaceGC::capacity_until_GC(); 2526 2527 const double minimum_free_percentage = MinMetaspaceFreeRatio / 100.0; 2528 const double maximum_used_percentage = 1.0 - minimum_free_percentage; 2529 2530 const double min_tmp = used_after_gc / maximum_used_percentage; 2531 size_t minimum_desired_capacity = 2532 (size_t)MIN2(min_tmp, double(max_uintx)); 2533 // Don't shrink less than the initial generation size 2534 minimum_desired_capacity = MAX2(minimum_desired_capacity, 2535 MetaspaceSize); 2536 2537 log_trace(gc, metaspace)("MetaspaceGC::compute_new_size: "); 2538 log_trace(gc, metaspace)(" minimum_free_percentage: %6.2f maximum_used_percentage: %6.2f", 2539 minimum_free_percentage, maximum_used_percentage); 2540 log_trace(gc, metaspace)(" used_after_gc : %6.1fKB", used_after_gc / (double) K); 2541 2542 2543 size_t shrink_bytes = 0; 2544 if (capacity_until_GC < minimum_desired_capacity) { 2545 // If we have less capacity below the metaspace HWM, then 2546 // increment the HWM. 2547 size_t expand_bytes = minimum_desired_capacity - capacity_until_GC; 2548 expand_bytes = align_up(expand_bytes, Metaspace::commit_alignment()); 2549 // Don't expand unless it's significant 2550 if (expand_bytes >= MinMetaspaceExpansion) { 2551 size_t new_capacity_until_GC = 0; 2552 bool succeeded = MetaspaceGC::inc_capacity_until_GC(expand_bytes, &new_capacity_until_GC); 2553 assert(succeeded, "Should always succesfully increment HWM when at safepoint"); 2554 2555 Metaspace::tracer()->report_gc_threshold(capacity_until_GC, 2556 new_capacity_until_GC, 2557 MetaspaceGCThresholdUpdater::ComputeNewSize); 2558 log_trace(gc, metaspace)(" expanding: minimum_desired_capacity: %6.1fKB expand_bytes: %6.1fKB MinMetaspaceExpansion: %6.1fKB new metaspace HWM: %6.1fKB", 2559 minimum_desired_capacity / (double) K, 2560 expand_bytes / (double) K, 2561 MinMetaspaceExpansion / (double) K, 2562 new_capacity_until_GC / (double) K); 2563 } 2564 return; 2565 } 2566 2567 // No expansion, now see if we want to shrink 2568 // We would never want to shrink more than this 2569 assert(capacity_until_GC >= minimum_desired_capacity, 2570 SIZE_FORMAT " >= " SIZE_FORMAT, 2571 capacity_until_GC, minimum_desired_capacity); 2572 size_t max_shrink_bytes = capacity_until_GC - minimum_desired_capacity; 2573 2574 // Should shrinking be considered? 2575 if (MaxMetaspaceFreeRatio < 100) { 2576 const double maximum_free_percentage = MaxMetaspaceFreeRatio / 100.0; 2577 const double minimum_used_percentage = 1.0 - maximum_free_percentage; 2578 const double max_tmp = used_after_gc / minimum_used_percentage; 2579 size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx)); 2580 maximum_desired_capacity = MAX2(maximum_desired_capacity, 2581 MetaspaceSize); 2582 log_trace(gc, metaspace)(" maximum_free_percentage: %6.2f minimum_used_percentage: %6.2f", 2583 maximum_free_percentage, minimum_used_percentage); 2584 log_trace(gc, metaspace)(" minimum_desired_capacity: %6.1fKB maximum_desired_capacity: %6.1fKB", 2585 minimum_desired_capacity / (double) K, maximum_desired_capacity / (double) K); 2586 2587 assert(minimum_desired_capacity <= maximum_desired_capacity, 2588 "sanity check"); 2589 2590 if (capacity_until_GC > maximum_desired_capacity) { 2591 // Capacity too large, compute shrinking size 2592 shrink_bytes = capacity_until_GC - maximum_desired_capacity; 2593 // We don't want shrink all the way back to initSize if people call 2594 // System.gc(), because some programs do that between "phases" and then 2595 // we'd just have to grow the heap up again for the next phase. So we 2596 // damp the shrinking: 0% on the first call, 10% on the second call, 40% 2597 // on the third call, and 100% by the fourth call. But if we recompute 2598 // size without shrinking, it goes back to 0%. 2599 shrink_bytes = shrink_bytes / 100 * current_shrink_factor; 2600 2601 shrink_bytes = align_down(shrink_bytes, Metaspace::commit_alignment()); 2602 2603 assert(shrink_bytes <= max_shrink_bytes, 2604 "invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT, 2605 shrink_bytes, max_shrink_bytes); 2606 if (current_shrink_factor == 0) { 2607 _shrink_factor = 10; 2608 } else { 2609 _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100); 2610 } 2611 log_trace(gc, metaspace)(" shrinking: initThreshold: %.1fK maximum_desired_capacity: %.1fK", 2612 MetaspaceSize / (double) K, maximum_desired_capacity / (double) K); 2613 log_trace(gc, metaspace)(" shrink_bytes: %.1fK current_shrink_factor: %d new shrink factor: %d MinMetaspaceExpansion: %.1fK", 2614 shrink_bytes / (double) K, current_shrink_factor, _shrink_factor, MinMetaspaceExpansion / (double) K); 2615 } 2616 } 2617 2618 // Don't shrink unless it's significant 2619 if (shrink_bytes >= MinMetaspaceExpansion && 2620 ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) { 2621 size_t new_capacity_until_GC = MetaspaceGC::dec_capacity_until_GC(shrink_bytes); 2622 Metaspace::tracer()->report_gc_threshold(capacity_until_GC, 2623 new_capacity_until_GC, 2624 MetaspaceGCThresholdUpdater::ComputeNewSize); 2625 } 2626 } 2627 2628 // Metadebug methods 2629 2630 void Metadebug::init_allocation_fail_alot_count() { 2631 if (MetadataAllocationFailALot) { 2632 _allocation_fail_alot_count = 2633 1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0)); 2634 } 2635 } 2636 2637 #ifdef ASSERT 2638 bool Metadebug::test_metadata_failure() { 2639 if (MetadataAllocationFailALot && 2640 Threads::is_vm_complete()) { 2641 if (_allocation_fail_alot_count > 0) { 2642 _allocation_fail_alot_count--; 2643 } else { 2644 log_trace(gc, metaspace, freelist)("Metadata allocation failing for MetadataAllocationFailALot"); 2645 init_allocation_fail_alot_count(); 2646 return true; 2647 } 2648 } 2649 return false; 2650 } 2651 #endif 2652 2653 // ChunkManager methods 2654 size_t ChunkManager::free_chunks_total_words() { 2655 return _free_chunks_total; 2656 } 2657 2658 size_t ChunkManager::free_chunks_total_bytes() { 2659 return free_chunks_total_words() * BytesPerWord; 2660 } 2661 2662 // Update internal accounting after a chunk was added 2663 void ChunkManager::account_for_added_chunk(const Metachunk* c) { 2664 assert_lock_strong(MetaspaceExpand_lock); 2665 _free_chunks_count ++; 2666 _free_chunks_total += c->word_size(); 2667 } 2668 2669 // Update internal accounting after a chunk was removed 2670 void ChunkManager::account_for_removed_chunk(const Metachunk* c) { 2671 assert_lock_strong(MetaspaceExpand_lock); 2672 assert(_free_chunks_count >= 1, 2673 "ChunkManager::_free_chunks_count: about to go negative (" SIZE_FORMAT ").", _free_chunks_count); 2674 assert(_free_chunks_total >= c->word_size(), 2675 "ChunkManager::_free_chunks_total: about to go negative" 2676 "(now: " SIZE_FORMAT ", decrement value: " SIZE_FORMAT ").", _free_chunks_total, c->word_size()); 2677 _free_chunks_count --; 2678 _free_chunks_total -= c->word_size(); 2679 } 2680 2681 size_t ChunkManager::free_chunks_count() { 2682 #ifdef ASSERT 2683 if (!UseConcMarkSweepGC && !MetaspaceExpand_lock->is_locked()) { 2684 MutexLockerEx cl(MetaspaceExpand_lock, 2685 Mutex::_no_safepoint_check_flag); 2686 // This lock is only needed in debug because the verification 2687 // of the _free_chunks_totals walks the list of free chunks 2688 slow_locked_verify_free_chunks_count(); 2689 } 2690 #endif 2691 return _free_chunks_count; 2692 } 2693 2694 ChunkIndex ChunkManager::list_index(size_t size) { 2695 return get_chunk_type_by_size(size, is_class()); 2696 } 2697 2698 size_t ChunkManager::size_by_index(ChunkIndex index) const { 2699 index_bounds_check(index); 2700 assert(index != HumongousIndex, "Do not call for humongous chunks."); 2701 return get_size_for_nonhumongous_chunktype(index, is_class()); 2702 } 2703 2704 void ChunkManager::locked_verify_free_chunks_total() { 2705 assert_lock_strong(MetaspaceExpand_lock); 2706 assert(sum_free_chunks() == _free_chunks_total, 2707 "_free_chunks_total " SIZE_FORMAT " is not the" 2708 " same as sum " SIZE_FORMAT, _free_chunks_total, 2709 sum_free_chunks()); 2710 } 2711 2712 void ChunkManager::verify_free_chunks_total() { 2713 MutexLockerEx cl(MetaspaceExpand_lock, 2714 Mutex::_no_safepoint_check_flag); 2715 locked_verify_free_chunks_total(); 2716 } 2717 2718 void ChunkManager::locked_verify_free_chunks_count() { 2719 assert_lock_strong(MetaspaceExpand_lock); 2720 assert(sum_free_chunks_count() == _free_chunks_count, 2721 "_free_chunks_count " SIZE_FORMAT " is not the" 2722 " same as sum " SIZE_FORMAT, _free_chunks_count, 2723 sum_free_chunks_count()); 2724 } 2725 2726 void ChunkManager::verify_free_chunks_count() { 2727 #ifdef ASSERT 2728 MutexLockerEx cl(MetaspaceExpand_lock, 2729 Mutex::_no_safepoint_check_flag); 2730 locked_verify_free_chunks_count(); 2731 #endif 2732 } 2733 2734 void ChunkManager::verify() { 2735 MutexLockerEx cl(MetaspaceExpand_lock, 2736 Mutex::_no_safepoint_check_flag); 2737 locked_verify(); 2738 } 2739 2740 void ChunkManager::locked_verify() { 2741 locked_verify_free_chunks_count(); 2742 locked_verify_free_chunks_total(); 2743 for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) { 2744 ChunkList* list = free_chunks(i); 2745 if (list != NULL) { 2746 Metachunk* chunk = list->head(); 2747 while (chunk) { 2748 DEBUG_ONLY(do_verify_chunk(chunk);) 2749 assert(chunk->is_tagged_free(), "Chunk should be tagged as free."); 2750 chunk = chunk->next(); 2751 } 2752 } 2753 } 2754 } 2755 2756 void ChunkManager::locked_print_free_chunks(outputStream* st) { 2757 assert_lock_strong(MetaspaceExpand_lock); 2758 st->print_cr("Free chunk total " SIZE_FORMAT " count " SIZE_FORMAT, 2759 _free_chunks_total, _free_chunks_count); 2760 } 2761 2762 void ChunkManager::locked_print_sum_free_chunks(outputStream* st) { 2763 assert_lock_strong(MetaspaceExpand_lock); 2764 st->print_cr("Sum free chunk total " SIZE_FORMAT " count " SIZE_FORMAT, 2765 sum_free_chunks(), sum_free_chunks_count()); 2766 } 2767 2768 ChunkList* ChunkManager::free_chunks(ChunkIndex index) { 2769 assert(index == SpecializedIndex || index == SmallIndex || index == MediumIndex, 2770 "Bad index: %d", (int)index); 2771 2772 return &_free_chunks[index]; 2773 } 2774 2775 // These methods that sum the free chunk lists are used in printing 2776 // methods that are used in product builds. 2777 size_t ChunkManager::sum_free_chunks() { 2778 assert_lock_strong(MetaspaceExpand_lock); 2779 size_t result = 0; 2780 for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) { 2781 ChunkList* list = free_chunks(i); 2782 2783 if (list == NULL) { 2784 continue; 2785 } 2786 2787 result = result + list->count() * list->size(); 2788 } 2789 result = result + humongous_dictionary()->total_size(); 2790 return result; 2791 } 2792 2793 size_t ChunkManager::sum_free_chunks_count() { 2794 assert_lock_strong(MetaspaceExpand_lock); 2795 size_t count = 0; 2796 for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) { 2797 ChunkList* list = free_chunks(i); 2798 if (list == NULL) { 2799 continue; 2800 } 2801 count = count + list->count(); 2802 } 2803 count = count + humongous_dictionary()->total_free_blocks(); 2804 return count; 2805 } 2806 2807 ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) { 2808 ChunkIndex index = list_index(word_size); 2809 assert(index < HumongousIndex, "No humongous list"); 2810 return free_chunks(index); 2811 } 2812 2813 // Helper for chunk splitting: given a target chunk size and a larger free chunk, 2814 // split up the larger chunk into n smaller chunks, at least one of which should be 2815 // the target chunk of target chunk size. The smaller chunks, including the target 2816 // chunk, are returned to the freelist. The pointer to the target chunk is returned. 2817 // Note that this chunk is supposed to be removed from the freelist right away. 2818 Metachunk* ChunkManager::split_chunk(size_t target_chunk_word_size, Metachunk* larger_chunk) { 2819 assert(larger_chunk->word_size() > target_chunk_word_size, "Sanity"); 2820 2821 const ChunkIndex larger_chunk_index = larger_chunk->get_chunk_type(); 2822 const ChunkIndex target_chunk_index = get_chunk_type_by_size(target_chunk_word_size, is_class()); 2823 2824 MetaWord* const region_start = (MetaWord*)larger_chunk; 2825 const size_t region_word_len = larger_chunk->word_size(); 2826 MetaWord* const region_end = region_start + region_word_len; 2827 VirtualSpaceNode* const vsn = larger_chunk->container(); 2828 OccupancyMap* const ocmap = vsn->occupancy_map(); 2829 2830 // Any larger non-humongous chunk size is a multiple of any smaller chunk size. 2831 // Since non-humongous chunks are aligned to their chunk size, the larger chunk should start 2832 // at an address suitable to place the smaller target chunk. 2833 assert_is_aligned(region_start, target_chunk_word_size); 2834 2835 // Remove old chunk. 2836 free_chunks(larger_chunk_index)->remove_chunk(larger_chunk); 2837 larger_chunk->remove_sentinel(); 2838 2839 // Prevent access to the old chunk from here on. 2840 larger_chunk = NULL; 2841 // ... and wipe it. 2842 DEBUG_ONLY(memset(region_start, 0xfe, region_word_len * BytesPerWord)); 2843 2844 // In its place create first the target chunk... 2845 MetaWord* p = region_start; 2846 Metachunk* target_chunk = ::new (p) Metachunk(target_chunk_index, is_class(), target_chunk_word_size, vsn); 2847 assert(target_chunk == (Metachunk*)p, "Sanity"); 2848 target_chunk->set_origin(origin_split); 2849 2850 // Note: we do not need to mark its start in the occupancy map 2851 // because it coincides with the old chunk start. 2852 2853 // Mark chunk as free and return to the freelist. 2854 do_update_in_use_info_for_chunk(target_chunk, false); 2855 free_chunks(target_chunk_index)->return_chunk_at_head(target_chunk); 2856 2857 // This chunk should now be valid and can be verified. 2858 DEBUG_ONLY(do_verify_chunk(target_chunk)); 2859 2860 // In the remaining space create the remainder chunks. 2861 p += target_chunk->word_size(); 2862 assert(p < region_end, "Sanity"); 2863 2864 while (p < region_end) { 2865 2866 // Find the largest chunk size which fits the alignment requirements at address p. 2867 ChunkIndex this_chunk_index = prev_chunk_index(larger_chunk_index); 2868 size_t this_chunk_word_size = 0; 2869 for(;;) { 2870 this_chunk_word_size = get_size_for_nonhumongous_chunktype(this_chunk_index, is_class()); 2871 if (is_aligned(p, this_chunk_word_size * BytesPerWord)) { 2872 break; 2873 } else { 2874 this_chunk_index = prev_chunk_index(this_chunk_index); 2875 assert(this_chunk_index >= target_chunk_index, "Sanity"); 2876 } 2877 } 2878 2879 assert(this_chunk_word_size >= target_chunk_word_size, "Sanity"); 2880 assert(is_aligned(p, this_chunk_word_size * BytesPerWord), "Sanity"); 2881 assert(p + this_chunk_word_size <= region_end, "Sanity"); 2882 2883 // Create splitting chunk. 2884 Metachunk* this_chunk = ::new (p) Metachunk(this_chunk_index, is_class(), this_chunk_word_size, vsn); 2885 assert(this_chunk == (Metachunk*)p, "Sanity"); 2886 this_chunk->set_origin(origin_split); 2887 ocmap->set_chunk_starts_at_address(p, true); 2888 do_update_in_use_info_for_chunk(this_chunk, false); 2889 2890 // This chunk should be valid and can be verified. 2891 DEBUG_ONLY(do_verify_chunk(this_chunk)); 2892 2893 // Return this chunk to freelist and correct counter. 2894 free_chunks(this_chunk_index)->return_chunk_at_head(this_chunk); 2895 _free_chunks_count ++; 2896 2897 log_trace(gc, metaspace, freelist)("Created chunk at " PTR_FORMAT ", word size " 2898 SIZE_FORMAT_HEX " (%s), in split region [" PTR_FORMAT "..." PTR_FORMAT ").", 2899 p2i(this_chunk), this_chunk->word_size(), chunk_size_name(this_chunk_index), 2900 p2i(region_start), p2i(region_end)); 2901 2902 p += this_chunk_word_size; 2903 2904 } 2905 2906 return target_chunk; 2907 } 2908 2909 Metachunk* ChunkManager::free_chunks_get(size_t word_size) { 2910 assert_lock_strong(MetaspaceExpand_lock); 2911 2912 slow_locked_verify(); 2913 2914 Metachunk* chunk = NULL; 2915 bool we_did_split_a_chunk = false; 2916 2917 if (list_index(word_size) != HumongousIndex) { 2918 2919 ChunkList* free_list = find_free_chunks_list(word_size); 2920 assert(free_list != NULL, "Sanity check"); 2921 2922 chunk = free_list->head(); 2923 2924 if (chunk == NULL) { 2925 // Split large chunks into smaller chunks if there are no smaller chunks, just large chunks. 2926 // This is the counterpart of the coalescing-upon-chunk-return. 2927 2928 ChunkIndex target_chunk_index = get_chunk_type_by_size(word_size, is_class()); 2929 2930 // Is there a larger chunk we could split? 2931 Metachunk* larger_chunk = NULL; 2932 ChunkIndex larger_chunk_index = next_chunk_index(target_chunk_index); 2933 while (larger_chunk == NULL && larger_chunk_index < NumberOfFreeLists) { 2934 larger_chunk = free_chunks(larger_chunk_index)->head(); 2935 if (larger_chunk == NULL) { 2936 larger_chunk_index = next_chunk_index(larger_chunk_index); 2937 } 2938 } 2939 2940 if (larger_chunk != NULL) { 2941 assert(larger_chunk->word_size() > word_size, "Sanity"); 2942 assert(larger_chunk->get_chunk_type() == larger_chunk_index, "Sanity"); 2943 2944 // We found a larger chunk. Lets split it up: 2945 // - remove old chunk 2946 // - in its place, create new smaller chunks, with at least one chunk 2947 // being of target size, the others sized as large as possible. This 2948 // is to make sure the resulting chunks are "as coalesced as possible" 2949 // (similar to VirtualSpaceNode::retire()). 2950 // Note: during this operation both ChunkManager and VirtualSpaceNode 2951 // are temporarily invalid, so be careful with asserts. 2952 2953 log_trace(gc, metaspace, freelist)("%s: splitting chunk " PTR_FORMAT 2954 ", word size " SIZE_FORMAT_HEX " (%s), to get a chunk of word size " SIZE_FORMAT_HEX " (%s)...", 2955 (is_class() ? "class space" : "metaspace"), p2i(larger_chunk), larger_chunk->word_size(), 2956 chunk_size_name(larger_chunk_index), word_size, chunk_size_name(target_chunk_index)); 2957 2958 chunk = split_chunk(word_size, larger_chunk); 2959 2960 // This should have worked. 2961 assert(chunk != NULL, "Sanity"); 2962 assert(chunk->word_size() == word_size, "Sanity"); 2963 assert(chunk->is_tagged_free(), "Sanity"); 2964 2965 we_did_split_a_chunk = true; 2966 2967 } 2968 } 2969 2970 if (chunk == NULL) { 2971 return NULL; 2972 } 2973 2974 // Remove the chunk as the head of the list. 2975 free_list->remove_chunk(chunk); 2976 2977 log_trace(gc, metaspace, freelist)("ChunkManager::free_chunks_get: free_list: " PTR_FORMAT " chunks left: " SSIZE_FORMAT ".", 2978 p2i(free_list), free_list->count()); 2979 2980 } else { 2981 chunk = humongous_dictionary()->get_chunk(word_size); 2982 2983 if (chunk == NULL) { 2984 return NULL; 2985 } 2986 2987 log_debug(gc, metaspace, alloc)("Free list allocate humongous chunk size " SIZE_FORMAT " for requested size " SIZE_FORMAT " waste " SIZE_FORMAT, 2988 chunk->word_size(), word_size, chunk->word_size() - word_size); 2989 } 2990 2991 // Chunk has been removed from the chunk manager; update counters. 2992 account_for_removed_chunk(chunk); 2993 do_update_in_use_info_for_chunk(chunk, true); 2994 chunk->container()->inc_container_count(); 2995 chunk->inc_use_count(); 2996 2997 // Remove it from the links to this freelist 2998 chunk->set_next(NULL); 2999 chunk->set_prev(NULL); 3000 3001 // Run some verifications (some more if we did a chunk split) 3002 #ifdef ASSERT 3003 if (VerifyMetaspace) { 3004 locked_verify(); 3005 VirtualSpaceNode* const vsn = chunk->container(); 3006 vsn->verify(); 3007 if (we_did_split_a_chunk) { 3008 vsn->verify_free_chunks_are_ideally_merged(); 3009 } 3010 } 3011 #endif 3012 3013 return chunk; 3014 } 3015 3016 Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) { 3017 assert_lock_strong(MetaspaceExpand_lock); 3018 slow_locked_verify(); 3019 3020 // Take from the beginning of the list 3021 Metachunk* chunk = free_chunks_get(word_size); 3022 if (chunk == NULL) { 3023 return NULL; 3024 } 3025 3026 assert((word_size <= chunk->word_size()) || 3027 (list_index(chunk->word_size()) == HumongousIndex), 3028 "Non-humongous variable sized chunk"); 3029 LogTarget(Debug, gc, metaspace, freelist) lt; 3030 if (lt.is_enabled()) { 3031 size_t list_count; 3032 if (list_index(word_size) < HumongousIndex) { 3033 ChunkList* list = find_free_chunks_list(word_size); 3034 list_count = list->count(); 3035 } else { 3036 list_count = humongous_dictionary()->total_count(); 3037 } 3038 LogStream ls(lt); 3039 ls.print("ChunkManager::chunk_freelist_allocate: " PTR_FORMAT " chunk " PTR_FORMAT " size " SIZE_FORMAT " count " SIZE_FORMAT " ", 3040 p2i(this), p2i(chunk), chunk->word_size(), list_count); 3041 ResourceMark rm; 3042 locked_print_free_chunks(&ls); 3043 ls.cr(); // ~LogStream does not autoflush. 3044 } 3045 3046 return chunk; 3047 } 3048 3049 void ChunkManager::return_single_chunk(ChunkIndex index, Metachunk* chunk) { 3050 assert_lock_strong(MetaspaceExpand_lock); 3051 DEBUG_ONLY(do_verify_chunk(chunk);) 3052 assert(chunk->get_chunk_type() == index, "Chunk does not match expected index."); 3053 assert(chunk != NULL, "Expected chunk."); 3054 assert(chunk->container() != NULL, "Container should have been set."); 3055 assert(chunk->is_tagged_free() == false, "Chunk should be in use."); 3056 index_bounds_check(index); 3057 3058 // Note: mangle *before* returning the chunk to the freelist or dictionary. It does not 3059 // matter for the freelist (non-humongous chunks), but the humongous chunk dictionary 3060 // keeps tree node pointers in the chunk payload area which mangle will overwrite. 3061 DEBUG_ONLY(chunk->mangle(badMetaWordVal);) 3062 3063 if (index != HumongousIndex) { 3064 // Return non-humongous chunk to freelist. 3065 ChunkList* list = free_chunks(index); 3066 assert(list->size() == chunk->word_size(), "Wrong chunk type."); 3067 list->return_chunk_at_head(chunk); 3068 log_trace(gc, metaspace, freelist)("returned one %s chunk at " PTR_FORMAT " to freelist.", 3069 chunk_size_name(index), p2i(chunk)); 3070 } else { 3071 // Return humongous chunk to dictionary. 3072 assert(chunk->word_size() > free_chunks(MediumIndex)->size(), "Wrong chunk type."); 3073 assert(chunk->word_size() % free_chunks(SpecializedIndex)->size() == 0, 3074 "Humongous chunk has wrong alignment."); 3075 _humongous_dictionary.return_chunk(chunk); 3076 log_trace(gc, metaspace, freelist)("returned one %s chunk at " PTR_FORMAT " (word size " SIZE_FORMAT ") to freelist.", 3077 chunk_size_name(index), p2i(chunk), chunk->word_size()); 3078 } 3079 chunk->container()->dec_container_count(); 3080 do_update_in_use_info_for_chunk(chunk, false); 3081 3082 // Chunk has been added; update counters. 3083 account_for_added_chunk(chunk); 3084 3085 // Attempt coalesce returned chunks with its neighboring chunks: 3086 // if this chunk is small or special, attempt to coalesce to a medium chunk. 3087 if (index == SmallIndex || index == SpecializedIndex) { 3088 if (!attempt_to_coalesce_around_chunk(chunk, MediumIndex)) { 3089 // This did not work. But if this chunk is special, we still may form a small chunk? 3090 if (index == SpecializedIndex) { 3091 if (!attempt_to_coalesce_around_chunk(chunk, SmallIndex)) { 3092 // give up. 3093 } 3094 } 3095 } 3096 } 3097 3098 } 3099 3100 void ChunkManager::return_chunk_list(ChunkIndex index, Metachunk* chunks) { 3101 index_bounds_check(index); 3102 if (chunks == NULL) { 3103 return; 3104 } 3105 LogTarget(Trace, gc, metaspace, freelist) log; 3106 if (log.is_enabled()) { // tracing 3107 log.print("returning list of %s chunks...", chunk_size_name(index)); 3108 } 3109 unsigned num_chunks_returned = 0; 3110 size_t size_chunks_returned = 0; 3111 Metachunk* cur = chunks; 3112 while (cur != NULL) { 3113 // Capture the next link before it is changed 3114 // by the call to return_chunk_at_head(); 3115 Metachunk* next = cur->next(); 3116 if (log.is_enabled()) { // tracing 3117 num_chunks_returned ++; 3118 size_chunks_returned += cur->word_size(); 3119 } 3120 return_single_chunk(index, cur); 3121 cur = next; 3122 } 3123 if (log.is_enabled()) { // tracing 3124 log.print("returned %u %s chunks to freelist, total word size " SIZE_FORMAT ".", 3125 num_chunks_returned, chunk_size_name(index), size_chunks_returned); 3126 if (index != HumongousIndex) { 3127 log.print("updated freelist count: " SIZE_FORMAT ".", free_chunks(index)->size()); 3128 } else { 3129 log.print("updated dictionary count " SIZE_FORMAT ".", _humongous_dictionary.total_count()); 3130 } 3131 } 3132 } 3133 3134 void ChunkManager::print_on(outputStream* out) const { 3135 _humongous_dictionary.report_statistics(out); 3136 } 3137 3138 void ChunkManager::collect_statistics(ChunkManagerStatistics* out) const { 3139 MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag); 3140 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3141 out->chunk_stats(i).add(num_free_chunks(i), size_free_chunks_in_bytes(i) / sizeof(MetaWord)); 3142 } 3143 } 3144 3145 // SpaceManager methods 3146 3147 size_t SpaceManager::adjust_initial_chunk_size(size_t requested, bool is_class_space) { 3148 size_t chunk_sizes[] = { 3149 specialized_chunk_size(is_class_space), 3150 small_chunk_size(is_class_space), 3151 medium_chunk_size(is_class_space) 3152 }; 3153 3154 // Adjust up to one of the fixed chunk sizes ... 3155 for (size_t i = 0; i < ARRAY_SIZE(chunk_sizes); i++) { 3156 if (requested <= chunk_sizes[i]) { 3157 return chunk_sizes[i]; 3158 } 3159 } 3160 3161 // ... or return the size as a humongous chunk. 3162 return requested; 3163 } 3164 3165 size_t SpaceManager::adjust_initial_chunk_size(size_t requested) const { 3166 return adjust_initial_chunk_size(requested, is_class()); 3167 } 3168 3169 size_t SpaceManager::get_initial_chunk_size(Metaspace::MetaspaceType type) const { 3170 size_t requested; 3171 3172 if (is_class()) { 3173 switch (type) { 3174 case Metaspace::BootMetaspaceType: requested = Metaspace::first_class_chunk_word_size(); break; 3175 case Metaspace::AnonymousMetaspaceType: requested = ClassSpecializedChunk; break; 3176 case Metaspace::ReflectionMetaspaceType: requested = ClassSpecializedChunk; break; 3177 default: requested = ClassSmallChunk; break; 3178 } 3179 } else { 3180 switch (type) { 3181 case Metaspace::BootMetaspaceType: requested = Metaspace::first_chunk_word_size(); break; 3182 case Metaspace::AnonymousMetaspaceType: requested = SpecializedChunk; break; 3183 case Metaspace::ReflectionMetaspaceType: requested = SpecializedChunk; break; 3184 default: requested = SmallChunk; break; 3185 } 3186 } 3187 3188 // Adjust to one of the fixed chunk sizes (unless humongous) 3189 const size_t adjusted = adjust_initial_chunk_size(requested); 3190 3191 assert(adjusted != 0, "Incorrect initial chunk size. Requested: " 3192 SIZE_FORMAT " adjusted: " SIZE_FORMAT, requested, adjusted); 3193 3194 return adjusted; 3195 } 3196 3197 size_t SpaceManager::sum_count_in_chunks_in_use(ChunkIndex i) { 3198 size_t count = 0; 3199 Metachunk* chunk = chunks_in_use(i); 3200 while (chunk != NULL) { 3201 count++; 3202 chunk = chunk->next(); 3203 } 3204 return count; 3205 } 3206 3207 void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const { 3208 3209 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3210 Metachunk* chunk = chunks_in_use(i); 3211 st->print("SpaceManager: %s " PTR_FORMAT, 3212 chunk_size_name(i), p2i(chunk)); 3213 if (chunk != NULL) { 3214 st->print_cr(" free " SIZE_FORMAT, 3215 chunk->free_word_size()); 3216 } else { 3217 st->cr(); 3218 } 3219 } 3220 3221 chunk_manager()->locked_print_free_chunks(st); 3222 chunk_manager()->locked_print_sum_free_chunks(st); 3223 } 3224 3225 size_t SpaceManager::calc_chunk_size(size_t word_size) { 3226 3227 // Decide between a small chunk and a medium chunk. Up to 3228 // _small_chunk_limit small chunks can be allocated. 3229 // After that a medium chunk is preferred. 3230 size_t chunk_word_size; 3231 3232 // Special case for anonymous metadata space. 3233 // Anonymous metadata space is usually small, with majority within 1K - 2K range and 3234 // rarely about 4K (64-bits JVM). 3235 // Instead of jumping to SmallChunk after initial chunk exhausted, keeping allocation 3236 // from SpecializeChunk up to _anon_or_delegating_metadata_specialize_chunk_limit (4) 3237 // reduces space waste from 60+% to around 30%. 3238 if ((_space_type == Metaspace::AnonymousMetaspaceType || _space_type == Metaspace::ReflectionMetaspaceType) && 3239 _mdtype == Metaspace::NonClassType && 3240 sum_count_in_chunks_in_use(SpecializedIndex) < _anon_and_delegating_metadata_specialize_chunk_limit && 3241 word_size + Metachunk::overhead() <= SpecializedChunk) { 3242 return SpecializedChunk; 3243 } 3244 3245 if (chunks_in_use(MediumIndex) == NULL && 3246 sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit) { 3247 chunk_word_size = (size_t) small_chunk_size(); 3248 if (word_size + Metachunk::overhead() > small_chunk_size()) { 3249 chunk_word_size = medium_chunk_size(); 3250 } 3251 } else { 3252 chunk_word_size = medium_chunk_size(); 3253 } 3254 3255 // Might still need a humongous chunk. Enforce 3256 // humongous allocations sizes to be aligned up to 3257 // the smallest chunk size. 3258 size_t if_humongous_sized_chunk = 3259 align_up(word_size + Metachunk::overhead(), 3260 smallest_chunk_size()); 3261 chunk_word_size = 3262 MAX2((size_t) chunk_word_size, if_humongous_sized_chunk); 3263 3264 assert(!SpaceManager::is_humongous(word_size) || 3265 chunk_word_size == if_humongous_sized_chunk, 3266 "Size calculation is wrong, word_size " SIZE_FORMAT 3267 " chunk_word_size " SIZE_FORMAT, 3268 word_size, chunk_word_size); 3269 Log(gc, metaspace, alloc) log; 3270 if (log.is_debug() && SpaceManager::is_humongous(word_size)) { 3271 log.debug("Metadata humongous allocation:"); 3272 log.debug(" word_size " PTR_FORMAT, word_size); 3273 log.debug(" chunk_word_size " PTR_FORMAT, chunk_word_size); 3274 log.debug(" chunk overhead " PTR_FORMAT, Metachunk::overhead()); 3275 } 3276 return chunk_word_size; 3277 } 3278 3279 void SpaceManager::track_metaspace_memory_usage() { 3280 if (is_init_completed()) { 3281 if (is_class()) { 3282 MemoryService::track_compressed_class_memory_usage(); 3283 } 3284 MemoryService::track_metaspace_memory_usage(); 3285 } 3286 } 3287 3288 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) { 3289 assert_lock_strong(_lock); 3290 assert(vs_list()->current_virtual_space() != NULL, 3291 "Should have been set"); 3292 assert(current_chunk() == NULL || 3293 current_chunk()->allocate(word_size) == NULL, 3294 "Don't need to expand"); 3295 MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag); 3296 3297 if (log_is_enabled(Trace, gc, metaspace, freelist)) { 3298 size_t words_left = 0; 3299 size_t words_used = 0; 3300 if (current_chunk() != NULL) { 3301 words_left = current_chunk()->free_word_size(); 3302 words_used = current_chunk()->used_word_size(); 3303 } 3304 log_trace(gc, metaspace, freelist)("SpaceManager::grow_and_allocate for " SIZE_FORMAT " words " SIZE_FORMAT " words used " SIZE_FORMAT " words left", 3305 word_size, words_used, words_left); 3306 } 3307 3308 // Get another chunk 3309 size_t chunk_word_size = calc_chunk_size(word_size); 3310 Metachunk* next = get_new_chunk(chunk_word_size); 3311 3312 MetaWord* mem = NULL; 3313 3314 // If a chunk was available, add it to the in-use chunk list 3315 // and do an allocation from it. 3316 if (next != NULL) { 3317 // Add to this manager's list of chunks in use. 3318 // If the new chunk is humongous, it was created to serve a single large allocation. In that 3319 // case it usually makes no sense to make it the current chunk, since the next allocation would 3320 // need to allocate a new chunk anyway, while we would now prematurely retire a perfectly 3321 // good chunk which could be used for more normal allocations. 3322 bool make_current = true; 3323 if (next->get_chunk_type() == HumongousIndex && 3324 current_chunk() != NULL) { 3325 make_current = false; 3326 } 3327 add_chunk(next, make_current); 3328 mem = next->allocate(word_size); 3329 } 3330 3331 // Track metaspace memory usage statistic. 3332 track_metaspace_memory_usage(); 3333 3334 return mem; 3335 } 3336 3337 void SpaceManager::print_on(outputStream* st) const { 3338 SpaceManagerStatistics stat; 3339 add_to_statistics(&stat); // will lock _lock. 3340 stat.print_on(st, 1*K, false); 3341 } 3342 3343 SpaceManager::SpaceManager(Metaspace::MetadataType mdtype, 3344 Metaspace::MetaspaceType space_type, 3345 Mutex* lock) : 3346 _mdtype(mdtype), 3347 _space_type(space_type), 3348 _capacity_words(0), 3349 _used_words(0), 3350 _overhead_words(0), 3351 _block_freelists(NULL), 3352 _lock(lock) 3353 { 3354 initialize(); 3355 } 3356 3357 void SpaceManager::account_for_new_chunk(const Metachunk* new_chunk) { 3358 3359 assert_lock_strong(MetaspaceExpand_lock); 3360 3361 _capacity_words += new_chunk->word_size(); 3362 _overhead_words += Metachunk::overhead(); 3363 3364 // Adjust global counters: 3365 MetaspaceUtils::inc_capacity(mdtype(), new_chunk->word_size()); 3366 MetaspaceUtils::inc_overhead(mdtype(), Metachunk::overhead()); 3367 } 3368 3369 void SpaceManager::account_for_allocation(size_t words) { 3370 // Note: we should be locked with the ClassloaderData-specific metaspace lock. 3371 // We may or may not be locked with the global metaspace expansion lock. 3372 assert_lock_strong(lock()); 3373 3374 // Add to the per SpaceManager totals. This can be done non-atomically. 3375 _used_words += words; 3376 3377 // Adjust global counters. This will be done atomically. 3378 MetaspaceUtils::inc_used(mdtype(), words); 3379 } 3380 3381 void SpaceManager::account_for_spacemanager_death() { 3382 3383 assert_lock_strong(MetaspaceExpand_lock); 3384 3385 MetaspaceUtils::dec_capacity(mdtype(), _capacity_words); 3386 MetaspaceUtils::dec_overhead(mdtype(), _overhead_words); 3387 MetaspaceUtils::dec_used(mdtype(), _used_words); 3388 } 3389 3390 void SpaceManager::initialize() { 3391 Metadebug::init_allocation_fail_alot_count(); 3392 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3393 _chunks_in_use[i] = NULL; 3394 } 3395 _current_chunk = NULL; 3396 log_trace(gc, metaspace, freelist)("SpaceManager(): " PTR_FORMAT, p2i(this)); 3397 } 3398 3399 SpaceManager::~SpaceManager() { 3400 3401 // This call this->_lock which can't be done while holding MetaspaceExpand_lock 3402 DEBUG_ONLY(verify_metrics()); 3403 3404 MutexLockerEx fcl(MetaspaceExpand_lock, 3405 Mutex::_no_safepoint_check_flag); 3406 3407 chunk_manager()->slow_locked_verify(); 3408 3409 account_for_spacemanager_death(); 3410 3411 Log(gc, metaspace, freelist) log; 3412 if (log.is_trace()) { 3413 log.trace("~SpaceManager(): " PTR_FORMAT, p2i(this)); 3414 ResourceMark rm; 3415 LogStream ls(log.trace()); 3416 locked_print_chunks_in_use_on(&ls); 3417 if (block_freelists() != NULL) { 3418 block_freelists()->print_on(&ls); 3419 } 3420 ls.cr(); // ~LogStream does not autoflush. 3421 } 3422 3423 // Add all the chunks in use by this space manager 3424 // to the global list of free chunks. 3425 3426 // Follow each list of chunks-in-use and add them to the 3427 // free lists. Each list is NULL terminated. 3428 3429 for (ChunkIndex i = ZeroIndex; i <= HumongousIndex; i = next_chunk_index(i)) { 3430 Metachunk* chunks = chunks_in_use(i); 3431 chunk_manager()->return_chunk_list(i, chunks); 3432 set_chunks_in_use(i, NULL); 3433 } 3434 3435 chunk_manager()->slow_locked_verify(); 3436 3437 if (_block_freelists != NULL) { 3438 delete _block_freelists; 3439 } 3440 } 3441 3442 void SpaceManager::deallocate(MetaWord* p, size_t word_size) { 3443 assert_lock_strong(lock()); 3444 // Allocations and deallocations are in raw_word_size 3445 size_t raw_word_size = get_allocation_word_size(word_size); 3446 // Lazily create a block_freelist 3447 if (block_freelists() == NULL) { 3448 _block_freelists = new BlockFreelist(); 3449 } 3450 block_freelists()->return_block(p, raw_word_size); 3451 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_deallocs)); 3452 } 3453 3454 // Adds a chunk to the list of chunks in use. 3455 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) { 3456 3457 assert_lock_strong(_lock); 3458 assert(new_chunk != NULL, "Should not be NULL"); 3459 assert(new_chunk->next() == NULL, "Should not be on a list"); 3460 3461 new_chunk->reset_empty(); 3462 3463 // Find the correct list and and set the current 3464 // chunk for that list. 3465 ChunkIndex index = chunk_manager()->list_index(new_chunk->word_size()); 3466 3467 if (make_current) { 3468 // If we are to make the chunk current, retire the old current chunk and replace 3469 // it with the new chunk. 3470 retire_current_chunk(); 3471 set_current_chunk(new_chunk); 3472 } 3473 3474 // Add the new chunk at the head of its respective chunk list. 3475 new_chunk->set_next(chunks_in_use(index)); 3476 set_chunks_in_use(index, new_chunk); 3477 3478 // Adjust counters. 3479 account_for_new_chunk(new_chunk); 3480 3481 assert(new_chunk->is_empty(), "Not ready for reuse"); 3482 Log(gc, metaspace, freelist) log; 3483 if (log.is_trace()) { 3484 log.trace("SpaceManager::added chunk: "); 3485 ResourceMark rm; 3486 LogStream ls(log.trace()); 3487 new_chunk->print_on(&ls); 3488 chunk_manager()->locked_print_free_chunks(&ls); 3489 ls.cr(); // ~LogStream does not autoflush. 3490 } 3491 } 3492 3493 void SpaceManager::retire_current_chunk() { 3494 if (current_chunk() != NULL) { 3495 size_t remaining_words = current_chunk()->free_word_size(); 3496 if (remaining_words >= BlockFreelist::min_dictionary_size()) { 3497 MetaWord* ptr = current_chunk()->allocate(remaining_words); 3498 deallocate(ptr, remaining_words); 3499 account_for_allocation(remaining_words); 3500 } 3501 } 3502 } 3503 3504 Metachunk* SpaceManager::get_new_chunk(size_t chunk_word_size) { 3505 // Get a chunk from the chunk freelist 3506 Metachunk* next = chunk_manager()->chunk_freelist_allocate(chunk_word_size); 3507 3508 if (next == NULL) { 3509 next = vs_list()->get_new_chunk(chunk_word_size, 3510 medium_chunk_bunch()); 3511 } 3512 3513 Log(gc, metaspace, alloc) log; 3514 if (log.is_debug() && next != NULL && 3515 SpaceManager::is_humongous(next->word_size())) { 3516 log.debug(" new humongous chunk word size " PTR_FORMAT, next->word_size()); 3517 } 3518 3519 return next; 3520 } 3521 3522 MetaWord* SpaceManager::allocate(size_t word_size) { 3523 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 3524 size_t raw_word_size = get_allocation_word_size(word_size); 3525 BlockFreelist* fl = block_freelists(); 3526 MetaWord* p = NULL; 3527 3528 DEBUG_ONLY(if (VerifyMetaspace) verify_metrics_locked()); 3529 3530 // Allocation from the dictionary is expensive in the sense that 3531 // the dictionary has to be searched for a size. Don't allocate 3532 // from the dictionary until it starts to get fat. Is this 3533 // a reasonable policy? Maybe an skinny dictionary is fast enough 3534 // for allocations. Do some profiling. JJJ 3535 if (fl != NULL && fl->total_size() > allocation_from_dictionary_limit) { 3536 p = fl->get_block(raw_word_size); 3537 if (p != NULL) { 3538 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_allocs_from_deallocated_blocks)); 3539 } 3540 } 3541 if (p == NULL) { 3542 p = allocate_work(raw_word_size); 3543 } 3544 3545 return p; 3546 } 3547 3548 // Returns the address of spaced allocated for "word_size". 3549 // This methods does not know about blocks (Metablocks) 3550 MetaWord* SpaceManager::allocate_work(size_t word_size) { 3551 assert_lock_strong(lock()); 3552 #ifdef ASSERT 3553 if (Metadebug::test_metadata_failure()) { 3554 return NULL; 3555 } 3556 #endif 3557 // Is there space in the current chunk? 3558 MetaWord* result = NULL; 3559 3560 if (current_chunk() != NULL) { 3561 result = current_chunk()->allocate(word_size); 3562 } 3563 3564 if (result == NULL) { 3565 result = grow_and_allocate(word_size); 3566 } 3567 3568 if (result != NULL) { 3569 account_for_allocation(word_size); 3570 assert(result != (MetaWord*) chunks_in_use(MediumIndex), 3571 "Head of the list is being allocated"); 3572 } 3573 3574 return result; 3575 } 3576 3577 void SpaceManager::verify() { 3578 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3579 Metachunk* curr = chunks_in_use(i); 3580 while (curr != NULL) { 3581 DEBUG_ONLY(do_verify_chunk(curr);) 3582 assert(curr->is_tagged_free() == false, "Chunk should be tagged as in use."); 3583 curr = curr->next(); 3584 } 3585 } 3586 } 3587 3588 void SpaceManager::verify_chunk_size(Metachunk* chunk) { 3589 assert(is_humongous(chunk->word_size()) || 3590 chunk->word_size() == medium_chunk_size() || 3591 chunk->word_size() == small_chunk_size() || 3592 chunk->word_size() == specialized_chunk_size(), 3593 "Chunk size is wrong"); 3594 return; 3595 } 3596 3597 void SpaceManager::add_to_statistics_locked(SpaceManagerStatistics* out) const { 3598 assert_lock_strong(lock()); 3599 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3600 UsedChunksStatistics& chunk_stat = out->chunk_stats(i); 3601 Metachunk* chunk = chunks_in_use(i); 3602 while (chunk != NULL) { 3603 chunk_stat.add_num(1); 3604 chunk_stat.add_cap(chunk->word_size()); 3605 chunk_stat.add_overhead(Metachunk::overhead()); 3606 chunk_stat.add_used(chunk->used_word_size() - Metachunk::overhead()); 3607 if (chunk != current_chunk()) { 3608 chunk_stat.add_waste(chunk->free_word_size()); 3609 } else { 3610 chunk_stat.add_free(chunk->free_word_size()); 3611 } 3612 chunk = chunk->next(); 3613 } 3614 } 3615 if (block_freelists() != NULL) { 3616 out->add_free_blocks_info(block_freelists()->num_blocks(), block_freelists()->total_size()); 3617 } 3618 } 3619 3620 void SpaceManager::add_to_statistics(SpaceManagerStatistics* out) const { 3621 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 3622 add_to_statistics_locked(out); 3623 } 3624 3625 #ifdef ASSERT 3626 void SpaceManager::verify_metrics_locked() const { 3627 assert_lock_strong(lock()); 3628 3629 SpaceManagerStatistics stat; 3630 add_to_statistics_locked(&stat); 3631 3632 UsedChunksStatistics chunk_stats = stat.totals(); 3633 3634 DEBUG_ONLY(chunk_stats.check_sanity()); 3635 3636 assert_counter(_capacity_words, chunk_stats.cap(), "SpaceManager::_capacity_words"); 3637 assert_counter(_used_words, chunk_stats.used(), "SpaceManager::_used_words"); 3638 assert_counter(_overhead_words, chunk_stats.overhead(), "SpaceManager::_overhead_words"); 3639 } 3640 3641 void SpaceManager::verify_metrics() const { 3642 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 3643 verify_metrics_locked(); 3644 } 3645 #endif // ASSERT 3646 3647 3648 3649 // MetaspaceUtils 3650 size_t MetaspaceUtils::_capacity_words [Metaspace:: MetadataTypeCount] = {0, 0}; 3651 size_t MetaspaceUtils::_overhead_words [Metaspace:: MetadataTypeCount] = {0, 0}; 3652 volatile size_t MetaspaceUtils::_used_words [Metaspace:: MetadataTypeCount] = {0, 0}; 3653 3654 // Collect used metaspace statistics. This involves walking the CLDG. The resulting 3655 // output will be the accumulated values for all live metaspaces. 3656 // Note: method does not do any locking. 3657 void MetaspaceUtils::collect_statistics(ClassLoaderMetaspaceStatistics* out) { 3658 out->reset(); 3659 ClassLoaderDataGraphMetaspaceIterator iter; 3660 while (iter.repeat()) { 3661 ClassLoaderMetaspace* msp = iter.get_next(); 3662 if (msp != NULL) { 3663 msp->add_to_statistics(out); 3664 } 3665 } 3666 } 3667 3668 size_t MetaspaceUtils::free_in_vs_bytes(Metaspace::MetadataType mdtype) { 3669 VirtualSpaceList* list = Metaspace::get_space_list(mdtype); 3670 return list == NULL ? 0 : list->free_bytes(); 3671 } 3672 3673 size_t MetaspaceUtils::free_in_vs_bytes() { 3674 return free_in_vs_bytes(Metaspace::ClassType) + free_in_vs_bytes(Metaspace::NonClassType); 3675 } 3676 3677 static void inc_stat_nonatomically(size_t* pstat, size_t words) { 3678 assert_lock_strong(MetaspaceExpand_lock); 3679 (*pstat) += words; 3680 } 3681 3682 static void dec_stat_nonatomically(size_t* pstat, size_t words) { 3683 assert_lock_strong(MetaspaceExpand_lock); 3684 const size_t size_now = *pstat; 3685 assert(size_now >= words, "About to decrement counter below zero " 3686 "(current value: " SIZE_FORMAT ", decrement value: " SIZE_FORMAT ".", 3687 size_now, words); 3688 *pstat = size_now - words; 3689 } 3690 3691 static void inc_stat_atomically(volatile size_t* pstat, size_t words) { 3692 Atomic::add(words, pstat); 3693 } 3694 3695 static void dec_stat_atomically(volatile size_t* pstat, size_t words) { 3696 const size_t size_now = *pstat; 3697 assert(size_now >= words, "About to decrement counter below zero " 3698 "(current value: " SIZE_FORMAT ", decrement value: " SIZE_FORMAT ".", 3699 size_now, words); 3700 Atomic::sub(words, pstat); 3701 } 3702 3703 void MetaspaceUtils::dec_capacity(Metaspace::MetadataType mdtype, size_t words) { 3704 dec_stat_nonatomically(&_capacity_words[mdtype], words); 3705 } 3706 void MetaspaceUtils::inc_capacity(Metaspace::MetadataType mdtype, size_t words) { 3707 inc_stat_nonatomically(&_capacity_words[mdtype], words); 3708 } 3709 void MetaspaceUtils::dec_used(Metaspace::MetadataType mdtype, size_t words) { 3710 dec_stat_atomically(&_used_words[mdtype], words); 3711 } 3712 void MetaspaceUtils::inc_used(Metaspace::MetadataType mdtype, size_t words) { 3713 inc_stat_atomically(&_used_words[mdtype], words); 3714 } 3715 void MetaspaceUtils::dec_overhead(Metaspace::MetadataType mdtype, size_t words) { 3716 dec_stat_nonatomically(&_overhead_words[mdtype], words); 3717 } 3718 void MetaspaceUtils::inc_overhead(Metaspace::MetadataType mdtype, size_t words) { 3719 inc_stat_nonatomically(&_overhead_words[mdtype], words); 3720 } 3721 3722 size_t MetaspaceUtils::reserved_bytes(Metaspace::MetadataType mdtype) { 3723 VirtualSpaceList* list = Metaspace::get_space_list(mdtype); 3724 return list == NULL ? 0 : list->reserved_bytes(); 3725 } 3726 3727 size_t MetaspaceUtils::committed_bytes(Metaspace::MetadataType mdtype) { 3728 VirtualSpaceList* list = Metaspace::get_space_list(mdtype); 3729 return list == NULL ? 0 : list->committed_bytes(); 3730 } 3731 3732 size_t MetaspaceUtils::min_chunk_size_words() { return Metaspace::first_chunk_word_size(); } 3733 3734 size_t MetaspaceUtils::free_chunks_total_words(Metaspace::MetadataType mdtype) { 3735 ChunkManager* chunk_manager = Metaspace::get_chunk_manager(mdtype); 3736 if (chunk_manager == NULL) { 3737 return 0; 3738 } 3739 chunk_manager->slow_verify(); 3740 return chunk_manager->free_chunks_total_words(); 3741 } 3742 3743 size_t MetaspaceUtils::free_chunks_total_bytes(Metaspace::MetadataType mdtype) { 3744 return free_chunks_total_words(mdtype) * BytesPerWord; 3745 } 3746 3747 size_t MetaspaceUtils::free_chunks_total_words() { 3748 return free_chunks_total_words(Metaspace::ClassType) + 3749 free_chunks_total_words(Metaspace::NonClassType); 3750 } 3751 3752 size_t MetaspaceUtils::free_chunks_total_bytes() { 3753 return free_chunks_total_words() * BytesPerWord; 3754 } 3755 3756 bool MetaspaceUtils::has_chunk_free_list(Metaspace::MetadataType mdtype) { 3757 return Metaspace::get_chunk_manager(mdtype) != NULL; 3758 } 3759 3760 MetaspaceChunkFreeListSummary MetaspaceUtils::chunk_free_list_summary(Metaspace::MetadataType mdtype) { 3761 if (!has_chunk_free_list(mdtype)) { 3762 return MetaspaceChunkFreeListSummary(); 3763 } 3764 3765 const ChunkManager* cm = Metaspace::get_chunk_manager(mdtype); 3766 return cm->chunk_free_list_summary(); 3767 } 3768 3769 void MetaspaceUtils::print_metaspace_change(size_t prev_metadata_used) { 3770 log_info(gc, metaspace)("Metaspace: " SIZE_FORMAT "K->" SIZE_FORMAT "K(" SIZE_FORMAT "K)", 3771 prev_metadata_used/K, used_bytes()/K, reserved_bytes()/K); 3772 } 3773 3774 void MetaspaceUtils::print_on(outputStream* out) { 3775 Metaspace::MetadataType nct = Metaspace::NonClassType; 3776 3777 out->print_cr(" Metaspace " 3778 "used " SIZE_FORMAT "K, " 3779 "capacity " SIZE_FORMAT "K, " 3780 "committed " SIZE_FORMAT "K, " 3781 "reserved " SIZE_FORMAT "K", 3782 used_bytes()/K, 3783 capacity_bytes()/K, 3784 committed_bytes()/K, 3785 reserved_bytes()/K); 3786 3787 if (Metaspace::using_class_space()) { 3788 Metaspace::MetadataType ct = Metaspace::ClassType; 3789 out->print_cr(" class space " 3790 "used " SIZE_FORMAT "K, " 3791 "capacity " SIZE_FORMAT "K, " 3792 "committed " SIZE_FORMAT "K, " 3793 "reserved " SIZE_FORMAT "K", 3794 used_bytes(ct)/K, 3795 capacity_bytes(ct)/K, 3796 committed_bytes(ct)/K, 3797 reserved_bytes(ct)/K); 3798 } 3799 } 3800 3801 class PrintCLDMetaspaceInfoClosure : public CLDClosure { 3802 private: 3803 outputStream* const _out; 3804 const size_t _scale; 3805 const bool _do_print; 3806 const bool _break_down_by_chunktype; 3807 3808 public: 3809 3810 uintx _num_loaders; 3811 ClassLoaderMetaspaceStatistics _stats_total; 3812 3813 uintx _num_loaders_by_spacetype [Metaspace::MetaspaceTypeCount]; 3814 ClassLoaderMetaspaceStatistics _stats_by_spacetype [Metaspace::MetaspaceTypeCount]; 3815 3816 public: 3817 PrintCLDMetaspaceInfoClosure(outputStream* out, size_t scale, bool do_print, bool break_down_by_chunktype) 3818 : _out(out), _scale(scale), _do_print(do_print), _break_down_by_chunktype(break_down_by_chunktype) 3819 , _num_loaders(0) 3820 { 3821 memset(_num_loaders_by_spacetype, 0, sizeof(_num_loaders_by_spacetype)); 3822 } 3823 3824 void do_cld(ClassLoaderData* cld) { 3825 3826 assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint"); 3827 3828 ClassLoaderMetaspace* msp = cld->metaspace_or_null(); 3829 if (msp == NULL) { 3830 return; 3831 } 3832 3833 // Collect statistics for this class loader metaspace 3834 ClassLoaderMetaspaceStatistics this_cld_stat; 3835 msp->add_to_statistics(&this_cld_stat); 3836 3837 // And add it to the running totals 3838 _stats_total.add(this_cld_stat); 3839 _num_loaders ++; 3840 _stats_by_spacetype[msp->space_type()].add(this_cld_stat); 3841 _num_loaders_by_spacetype[msp->space_type()] ++; 3842 3843 // Optionally, print. 3844 if (_do_print) { 3845 3846 _out->print(UINTX_FORMAT_W(4) ": ", _num_loaders); 3847 3848 if (cld->is_anonymous()) { 3849 _out->print("ClassLoaderData " PTR_FORMAT " for anonymous class", p2i(cld)); 3850 } else { 3851 ResourceMark rm; 3852 _out->print("ClassLoaderData " PTR_FORMAT " for %s", p2i(cld), cld->loader_name()); 3853 } 3854 3855 if (cld->is_unloading()) { 3856 _out->print(" (unloading)"); 3857 } 3858 3859 this_cld_stat.print_on(_out, _scale, _break_down_by_chunktype); 3860 _out->cr(); 3861 3862 } 3863 3864 } // do_cld 3865 3866 }; 3867 3868 void MetaspaceUtils::print_vs(outputStream* out, size_t scale) { 3869 const size_t reserved_nonclass_words = reserved_bytes(Metaspace::NonClassType) / sizeof(MetaWord); 3870 const size_t committed_nonclass_words = committed_bytes(Metaspace::NonClassType) / sizeof(MetaWord); 3871 { 3872 if (Metaspace::using_class_space()) { 3873 out->print(" Non-class space: "); 3874 } 3875 print_scaled_words(out, reserved_nonclass_words, scale, 7); 3876 out->print(" reserved, "); 3877 print_scaled_words_and_percentage(out, committed_nonclass_words, reserved_nonclass_words, scale, 7); 3878 out->print_cr(" committed "); 3879 3880 if (Metaspace::using_class_space()) { 3881 const size_t reserved_class_words = reserved_bytes(Metaspace::ClassType) / sizeof(MetaWord); 3882 const size_t committed_class_words = committed_bytes(Metaspace::ClassType) / sizeof(MetaWord); 3883 out->print(" Class space: "); 3884 print_scaled_words(out, reserved_class_words, scale, 7); 3885 out->print(" reserved, "); 3886 print_scaled_words_and_percentage(out, committed_class_words, reserved_class_words, scale, 7); 3887 out->print_cr(" committed "); 3888 3889 const size_t reserved_words = reserved_nonclass_words + reserved_class_words; 3890 const size_t committed_words = committed_nonclass_words + committed_class_words; 3891 out->print(" Both: "); 3892 print_scaled_words(out, reserved_words, scale, 7); 3893 out->print(" reserved, "); 3894 print_scaled_words_and_percentage(out, committed_words, reserved_words, scale, 7); 3895 out->print_cr(" committed "); 3896 } 3897 } 3898 } 3899 3900 // This will print out a basic metaspace usage report but 3901 // unlike print_report() is guaranteed not to lock or to walk the CLDG. 3902 void MetaspaceUtils::print_basic_report(outputStream* out, size_t scale) { 3903 3904 out->cr(); 3905 out->print_cr("Usage:"); 3906 3907 if (Metaspace::using_class_space()) { 3908 out->print(" Non-class: "); 3909 } 3910 3911 // In its most basic form, we do not require walking the CLDG. Instead, just print the running totals from 3912 // MetaspaceUtils. 3913 const size_t cap_nc = MetaspaceUtils::capacity_words(Metaspace::NonClassType); 3914 const size_t overhead_nc = MetaspaceUtils::overhead_words(Metaspace::NonClassType); 3915 const size_t used_nc = MetaspaceUtils::used_words(Metaspace::NonClassType); 3916 const size_t free_and_waste_nc = cap_nc - overhead_nc - used_nc; 3917 3918 print_scaled_words(out, cap_nc, scale, 5); 3919 out->print(" capacity, "); 3920 print_scaled_words_and_percentage(out, used_nc, cap_nc, scale, 5); 3921 out->print(" used, "); 3922 print_scaled_words_and_percentage(out, free_and_waste_nc, cap_nc, scale, 5); 3923 out->print(" free+waste, "); 3924 print_scaled_words_and_percentage(out, overhead_nc, cap_nc, scale, 5); 3925 out->print(" overhead. "); 3926 out->cr(); 3927 3928 if (Metaspace::using_class_space()) { 3929 const size_t cap_c = MetaspaceUtils::capacity_words(Metaspace::ClassType); 3930 const size_t overhead_c = MetaspaceUtils::overhead_words(Metaspace::ClassType); 3931 const size_t used_c = MetaspaceUtils::used_words(Metaspace::ClassType); 3932 const size_t free_and_waste_c = cap_c - overhead_c - used_c; 3933 out->print(" Class: "); 3934 print_scaled_words(out, cap_c, scale, 5); 3935 out->print(" capacity, "); 3936 print_scaled_words_and_percentage(out, used_c, cap_c, scale, 5); 3937 out->print(" used, "); 3938 print_scaled_words_and_percentage(out, free_and_waste_c, cap_c, scale, 5); 3939 out->print(" free+waste, "); 3940 print_scaled_words_and_percentage(out, overhead_c, cap_c, scale, 5); 3941 out->print(" overhead. "); 3942 out->cr(); 3943 3944 out->print(" Both: "); 3945 const size_t cap = cap_nc + cap_c; 3946 3947 print_scaled_words(out, cap, scale, 5); 3948 out->print(" capacity, "); 3949 print_scaled_words_and_percentage(out, used_nc + used_c, cap, scale, 5); 3950 out->print(" used, "); 3951 print_scaled_words_and_percentage(out, free_and_waste_nc + free_and_waste_c, cap, scale, 5); 3952 out->print(" free+waste, "); 3953 print_scaled_words_and_percentage(out, overhead_nc + overhead_c, cap, scale, 5); 3954 out->print(" overhead. "); 3955 out->cr(); 3956 } 3957 3958 out->cr(); 3959 out->print_cr("Virtual space:"); 3960 3961 print_vs(out, scale); 3962 3963 out->cr(); 3964 out->print_cr("Chunk freelists:"); 3965 3966 if (Metaspace::using_class_space()) { 3967 out->print(" Non-Class: "); 3968 } 3969 out->print_human_readable_size(Metaspace::chunk_manager_metadata()->free_chunks_total_words(), scale); 3970 out->cr(); 3971 if (Metaspace::using_class_space()) { 3972 out->print(" Class: "); 3973 out->print_human_readable_size(Metaspace::chunk_manager_class()->free_chunks_total_words(), scale); 3974 out->cr(); 3975 out->print(" Both: "); 3976 out->print_human_readable_size(Metaspace::chunk_manager_class()->free_chunks_total_words() + 3977 Metaspace::chunk_manager_metadata()->free_chunks_total_words(), scale); 3978 out->cr(); 3979 } 3980 out->cr(); 3981 3982 } 3983 3984 void MetaspaceUtils::print_report(outputStream* out, size_t scale, int flags) { 3985 3986 const bool print_loaders = (flags & rf_show_loaders) > 0; 3987 const bool print_by_chunktype = (flags & rf_break_down_by_chunktype) > 0; 3988 const bool print_by_spacetype = (flags & rf_break_down_by_spacetype) > 0; 3989 3990 // Some report options require walking the class loader data graph. 3991 PrintCLDMetaspaceInfoClosure cl(out, scale, print_loaders, print_by_chunktype); 3992 if (print_loaders) { 3993 out->cr(); 3994 out->print_cr("Usage per loader:"); 3995 out->cr(); 3996 } 3997 3998 ClassLoaderDataGraph::cld_do(&cl); // collect data and optionally print 3999 4000 // Print totals, broken up by space type. 4001 if (print_by_spacetype) { 4002 out->cr(); 4003 out->print_cr("Usage per space type:"); 4004 out->cr(); 4005 for (int space_type = (int)Metaspace::ZeroMetaspaceType; 4006 space_type < (int)Metaspace::MetaspaceTypeCount; space_type ++) 4007 { 4008 uintx num = cl._num_loaders_by_spacetype[space_type]; 4009 out->print("%s (" UINTX_FORMAT " loader%s)%c", 4010 space_type_name((Metaspace::MetaspaceType)space_type), 4011 num, (num == 1 ? "" : "s"), (num > 0 ? ':' : '.')); 4012 if (num > 0) { 4013 cl._stats_by_spacetype[space_type].print_on(out, scale, print_by_chunktype); 4014 } 4015 out->cr(); 4016 } 4017 } 4018 4019 // Print totals for in-use data: 4020 out->cr(); 4021 out->print_cr("Total Usage ( " UINTX_FORMAT " loader%s)%c", 4022 cl._num_loaders, (cl._num_loaders == 1 ? "" : "s"), (cl._num_loaders > 0 ? ':' : '.')); 4023 4024 cl._stats_total.print_on(out, scale, print_by_chunktype); 4025 4026 // -- Print Virtual space. 4027 out->cr(); 4028 out->print_cr("Virtual space:"); 4029 4030 print_vs(out, scale); 4031 4032 // -- Print VirtualSpaceList details. 4033 if ((flags & rf_show_vslist) > 0) { 4034 out->cr(); 4035 out->print_cr("Virtual space list%s:", Metaspace::using_class_space() ? "s" : ""); 4036 4037 if (Metaspace::using_class_space()) { 4038 out->print_cr(" Non-Class:"); 4039 } 4040 Metaspace::space_list()->print_on(out, scale); 4041 if (Metaspace::using_class_space()) { 4042 out->print_cr(" Class:"); 4043 Metaspace::class_space_list()->print_on(out, scale); 4044 } 4045 } 4046 out->cr(); 4047 4048 // -- Print VirtualSpaceList map. 4049 if ((flags & rf_show_vsmap) > 0) { 4050 out->cr(); 4051 out->print_cr("Virtual space map:"); 4052 4053 if (Metaspace::using_class_space()) { 4054 out->print_cr(" Non-Class:"); 4055 } 4056 Metaspace::space_list()->print_map(out); 4057 if (Metaspace::using_class_space()) { 4058 out->print_cr(" Class:"); 4059 Metaspace::class_space_list()->print_map(out); 4060 } 4061 } 4062 out->cr(); 4063 4064 // -- Print Freelists (ChunkManager) details 4065 out->cr(); 4066 out->print_cr("Chunk freelist%s:", Metaspace::using_class_space() ? "s" : ""); 4067 4068 ChunkManagerStatistics non_class_cm_stat; 4069 Metaspace::chunk_manager_metadata()->collect_statistics(&non_class_cm_stat); 4070 4071 if (Metaspace::using_class_space()) { 4072 out->print_cr(" Non-Class:"); 4073 } 4074 non_class_cm_stat.print_on(out, scale); 4075 4076 if (Metaspace::using_class_space()) { 4077 ChunkManagerStatistics class_cm_stat; 4078 Metaspace::chunk_manager_class()->collect_statistics(&class_cm_stat); 4079 out->print_cr(" Class:"); 4080 class_cm_stat.print_on(out, scale); 4081 } 4082 4083 // As a convenience, print a summary of common waste. 4084 out->cr(); 4085 out->print("Waste: "); 4086 // For all wastages, print percentages from total. As total use the total size of memory committed for metaspace. 4087 const size_t committed_words = committed_bytes() / BytesPerWord; 4088 4089 out->print("(Percentage values refer to total committed size ("); 4090 print_scaled_words(out, committed_words, scale); 4091 out->print_cr(")."); 4092 4093 // Print waste for in-use chunks. 4094 UsedChunksStatistics ucs_nonclass = cl._stats_total.nonclass_sm_stats().totals(); 4095 UsedChunksStatistics ucs_class = cl._stats_total.class_sm_stats().totals(); 4096 UsedChunksStatistics ucs_all; 4097 ucs_all.add(ucs_nonclass); 4098 ucs_all.add(ucs_class); 4099 out->print(" Waste in chunks in use: "); 4100 print_scaled_words_and_percentage(out, ucs_all.waste(), committed_words, scale, 6); 4101 out->cr(); 4102 out->print(" Free in chunks in use: "); 4103 print_scaled_words_and_percentage(out, ucs_all.free(), committed_words, scale, 6); 4104 out->cr(); 4105 4106 // Print waste in free chunks. 4107 const size_t total_capacity_in_free_chunks = 4108 Metaspace::chunk_manager_metadata()->free_chunks_total_words() + 4109 (Metaspace::using_class_space() ? Metaspace::chunk_manager_class()->free_chunks_total_words() : 0); 4110 out->print(" In free chunks: "); 4111 print_scaled_words_and_percentage(out, total_capacity_in_free_chunks, committed_words, scale, 6); 4112 out->cr(); 4113 4114 // Print waste in deallocated blocks. 4115 const uintx free_blocks_num = 4116 cl._stats_total.nonclass_sm_stats().free_blocks_num() + 4117 cl._stats_total.class_sm_stats().free_blocks_num(); 4118 const size_t free_blocks_cap_words = 4119 cl._stats_total.nonclass_sm_stats().free_blocks_cap_words() + 4120 cl._stats_total.class_sm_stats().free_blocks_cap_words(); 4121 out->print("Deallocated from chunks in use: " UINTX_FORMAT " blocks, total size ", free_blocks_num); 4122 print_scaled_words_and_percentage(out, free_blocks_cap_words, committed_words, scale, 6); 4123 out->cr(); 4124 4125 // Print internal statistics 4126 #ifdef ASSERT 4127 out->cr(); 4128 out->cr(); 4129 out->print_cr("Internal statistics:"); 4130 out->cr(); 4131 out->print_cr("Number of allocations: " UINTX_FORMAT ".", g_internal_statistics.num_allocs); 4132 out->print_cr("Number of space births: " UINTX_FORMAT ".", g_internal_statistics.num_metaspace_births); 4133 out->print_cr("Number of space deaths: " UINTX_FORMAT ".", g_internal_statistics.num_metaspace_deaths); 4134 out->print_cr("Number of virtual space node births: " UINTX_FORMAT ".", g_internal_statistics.num_vsnodes_created); 4135 out->print_cr("Number of virtual space node deaths: " UINTX_FORMAT ".", g_internal_statistics.num_vsnodes_purged); 4136 out->print_cr("Number of times virtual space nodes were expanded: " UINTX_FORMAT ".", g_internal_statistics.num_committed_space_expanded); 4137 out->print_cr("Number of deallocations: " UINTX_FORMAT " (" UINTX_FORMAT " external).", g_internal_statistics.num_deallocs, g_internal_statistics.num_external_deallocs); 4138 out->print_cr("Allocations from deallocated blocks: " UINTX_FORMAT ".", g_internal_statistics.num_allocs_from_deallocated_blocks); 4139 out->cr(); 4140 #endif 4141 4142 // Print some interesting settings 4143 out->cr(); 4144 out->cr(); 4145 out->print("MaxMetaspaceSize: "); 4146 out->print_human_readable_size(MaxMetaspaceSize, scale); 4147 out->cr(); 4148 out->print("InitialBootClassLoaderMetaspaceSize: "); 4149 out->print_human_readable_size(InitialBootClassLoaderMetaspaceSize, scale); 4150 out->cr(); 4151 4152 out->print("UseCompressedClassPointers: %s", UseCompressedClassPointers ? "true" : "false"); 4153 out->cr(); 4154 if (Metaspace::using_class_space()) { 4155 out->print("CompressedClassSpaceSize: "); 4156 out->print_human_readable_size(CompressedClassSpaceSize, scale); 4157 } 4158 4159 out->cr(); 4160 out->cr(); 4161 4162 } // MetaspaceUtils::print_report() 4163 4164 // Prints an ASCII representation of the given space. 4165 void MetaspaceUtils::print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype) { 4166 MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag); 4167 const bool for_class = mdtype == Metaspace::ClassType ? true : false; 4168 VirtualSpaceList* const vsl = for_class ? Metaspace::class_space_list() : Metaspace::space_list(); 4169 if (vsl != NULL) { 4170 if (for_class) { 4171 if (!Metaspace::using_class_space()) { 4172 out->print_cr("No Class Space."); 4173 return; 4174 } 4175 out->print_raw("---- Metaspace Map (Class Space) ----"); 4176 } else { 4177 out->print_raw("---- Metaspace Map (Non-Class Space) ----"); 4178 } 4179 // Print legend: 4180 out->cr(); 4181 out->print_cr("Chunk Types (uppercase chunks are in use): x-specialized, s-small, m-medium, h-humongous."); 4182 out->cr(); 4183 VirtualSpaceList* const vsl = for_class ? Metaspace::class_space_list() : Metaspace::space_list(); 4184 vsl->print_map(out); 4185 out->cr(); 4186 } 4187 } 4188 4189 void MetaspaceUtils::verify_free_chunks() { 4190 Metaspace::chunk_manager_metadata()->verify(); 4191 if (Metaspace::using_class_space()) { 4192 Metaspace::chunk_manager_class()->verify(); 4193 } 4194 } 4195 4196 void MetaspaceUtils::verify_metrics() { 4197 #ifdef ASSERT 4198 // Please note: there are time windows where the internal counters are out of sync with 4199 // reality. For example, when a newly created ClassLoaderMetaspace creates its first chunk - 4200 // the ClassLoaderMetaspace is not yet attached to its ClassLoaderData object and hence will 4201 // not be counted when iterating the CLDG. So be careful when you call this method. 4202 ClassLoaderMetaspaceStatistics total_stat; 4203 collect_statistics(&total_stat); 4204 UsedChunksStatistics nonclass_chunk_stat = total_stat.nonclass_sm_stats().totals(); 4205 UsedChunksStatistics class_chunk_stat = total_stat.class_sm_stats().totals(); 4206 4207 bool mismatch = false; 4208 for (int i = 0; i < Metaspace::MetadataTypeCount; i ++) { 4209 Metaspace::MetadataType mdtype = (Metaspace::MetadataType)i; 4210 UsedChunksStatistics chunk_stat = total_stat.sm_stats(mdtype).totals(); 4211 if (capacity_words(mdtype) != chunk_stat.cap() || 4212 used_words(mdtype) != chunk_stat.used() || 4213 overhead_words(mdtype) != chunk_stat.overhead()) { 4214 mismatch = true; 4215 tty->print_cr("MetaspaceUtils::verify_metrics: counter mismatch for mdtype=%u:", mdtype); 4216 tty->print_cr("Expected cap " SIZE_FORMAT ", used " SIZE_FORMAT ", overhead " SIZE_FORMAT ".", 4217 capacity_words(mdtype), used_words(mdtype), overhead_words(mdtype)); 4218 tty->print_cr("Got cap " SIZE_FORMAT ", used " SIZE_FORMAT ", overhead " SIZE_FORMAT ".", 4219 chunk_stat.cap(), chunk_stat.used(), chunk_stat.overhead()); 4220 tty->flush(); 4221 } 4222 } 4223 assert(mismatch == false, "MetaspaceUtils::verify_metrics: counter mismatch."); 4224 #endif 4225 } 4226 4227 4228 // Metaspace methods 4229 4230 size_t Metaspace::_first_chunk_word_size = 0; 4231 size_t Metaspace::_first_class_chunk_word_size = 0; 4232 4233 size_t Metaspace::_commit_alignment = 0; 4234 size_t Metaspace::_reserve_alignment = 0; 4235 4236 VirtualSpaceList* Metaspace::_space_list = NULL; 4237 VirtualSpaceList* Metaspace::_class_space_list = NULL; 4238 4239 ChunkManager* Metaspace::_chunk_manager_metadata = NULL; 4240 ChunkManager* Metaspace::_chunk_manager_class = NULL; 4241 4242 #define VIRTUALSPACEMULTIPLIER 2 4243 4244 #ifdef _LP64 4245 static const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1); 4246 4247 void Metaspace::set_narrow_klass_base_and_shift(address metaspace_base, address cds_base) { 4248 assert(!DumpSharedSpaces, "narrow_klass is set by MetaspaceShared class."); 4249 // Figure out the narrow_klass_base and the narrow_klass_shift. The 4250 // narrow_klass_base is the lower of the metaspace base and the cds base 4251 // (if cds is enabled). The narrow_klass_shift depends on the distance 4252 // between the lower base and higher address. 4253 address lower_base; 4254 address higher_address; 4255 #if INCLUDE_CDS 4256 if (UseSharedSpaces) { 4257 higher_address = MAX2((address)(cds_base + MetaspaceShared::core_spaces_size()), 4258 (address)(metaspace_base + compressed_class_space_size())); 4259 lower_base = MIN2(metaspace_base, cds_base); 4260 } else 4261 #endif 4262 { 4263 higher_address = metaspace_base + compressed_class_space_size(); 4264 lower_base = metaspace_base; 4265 4266 uint64_t klass_encoding_max = UnscaledClassSpaceMax << LogKlassAlignmentInBytes; 4267 // If compressed class space fits in lower 32G, we don't need a base. 4268 if (higher_address <= (address)klass_encoding_max) { 4269 lower_base = 0; // Effectively lower base is zero. 4270 } 4271 } 4272 4273 Universe::set_narrow_klass_base(lower_base); 4274 4275 // CDS uses LogKlassAlignmentInBytes for narrow_klass_shift. See 4276 // MetaspaceShared::initialize_dumptime_shared_and_meta_spaces() for 4277 // how dump time narrow_klass_shift is set. Although, CDS can work 4278 // with zero-shift mode also, to be consistent with AOT it uses 4279 // LogKlassAlignmentInBytes for klass shift so archived java heap objects 4280 // can be used at same time as AOT code. 4281 if (!UseSharedSpaces 4282 && (uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax) { 4283 Universe::set_narrow_klass_shift(0); 4284 } else { 4285 Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes); 4286 } 4287 AOTLoader::set_narrow_klass_shift(); 4288 } 4289 4290 #if INCLUDE_CDS 4291 // Return TRUE if the specified metaspace_base and cds_base are close enough 4292 // to work with compressed klass pointers. 4293 bool Metaspace::can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base) { 4294 assert(cds_base != 0 && UseSharedSpaces, "Only use with CDS"); 4295 assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs"); 4296 address lower_base = MIN2((address)metaspace_base, cds_base); 4297 address higher_address = MAX2((address)(cds_base + MetaspaceShared::core_spaces_size()), 4298 (address)(metaspace_base + compressed_class_space_size())); 4299 return ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax); 4300 } 4301 #endif 4302 4303 // Try to allocate the metaspace at the requested addr. 4304 void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base) { 4305 assert(!DumpSharedSpaces, "compress klass space is allocated by MetaspaceShared class."); 4306 assert(using_class_space(), "called improperly"); 4307 assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs"); 4308 assert(compressed_class_space_size() < KlassEncodingMetaspaceMax, 4309 "Metaspace size is too big"); 4310 assert_is_aligned(requested_addr, _reserve_alignment); 4311 assert_is_aligned(cds_base, _reserve_alignment); 4312 assert_is_aligned(compressed_class_space_size(), _reserve_alignment); 4313 4314 // Don't use large pages for the class space. 4315 bool large_pages = false; 4316 4317 #if !(defined(AARCH64) || defined(AIX)) 4318 ReservedSpace metaspace_rs = ReservedSpace(compressed_class_space_size(), 4319 _reserve_alignment, 4320 large_pages, 4321 requested_addr); 4322 #else // AARCH64 4323 ReservedSpace metaspace_rs; 4324 4325 // Our compressed klass pointers may fit nicely into the lower 32 4326 // bits. 4327 if ((uint64_t)requested_addr + compressed_class_space_size() < 4*G) { 4328 metaspace_rs = ReservedSpace(compressed_class_space_size(), 4329 _reserve_alignment, 4330 large_pages, 4331 requested_addr); 4332 } 4333 4334 if (! metaspace_rs.is_reserved()) { 4335 // Aarch64: Try to align metaspace so that we can decode a compressed 4336 // klass with a single MOVK instruction. We can do this iff the 4337 // compressed class base is a multiple of 4G. 4338 // Aix: Search for a place where we can find memory. If we need to load 4339 // the base, 4G alignment is helpful, too. 4340 size_t increment = AARCH64_ONLY(4*)G; 4341 for (char *a = align_up(requested_addr, increment); 4342 a < (char*)(1024*G); 4343 a += increment) { 4344 if (a == (char *)(32*G)) { 4345 // Go faster from here on. Zero-based is no longer possible. 4346 increment = 4*G; 4347 } 4348 4349 #if INCLUDE_CDS 4350 if (UseSharedSpaces 4351 && ! can_use_cds_with_metaspace_addr(a, cds_base)) { 4352 // We failed to find an aligned base that will reach. Fall 4353 // back to using our requested addr. 4354 metaspace_rs = ReservedSpace(compressed_class_space_size(), 4355 _reserve_alignment, 4356 large_pages, 4357 requested_addr); 4358 break; 4359 } 4360 #endif 4361 4362 metaspace_rs = ReservedSpace(compressed_class_space_size(), 4363 _reserve_alignment, 4364 large_pages, 4365 a); 4366 if (metaspace_rs.is_reserved()) 4367 break; 4368 } 4369 } 4370 4371 #endif // AARCH64 4372 4373 if (!metaspace_rs.is_reserved()) { 4374 #if INCLUDE_CDS 4375 if (UseSharedSpaces) { 4376 size_t increment = align_up(1*G, _reserve_alignment); 4377 4378 // Keep trying to allocate the metaspace, increasing the requested_addr 4379 // by 1GB each time, until we reach an address that will no longer allow 4380 // use of CDS with compressed klass pointers. 4381 char *addr = requested_addr; 4382 while (!metaspace_rs.is_reserved() && (addr + increment > addr) && 4383 can_use_cds_with_metaspace_addr(addr + increment, cds_base)) { 4384 addr = addr + increment; 4385 metaspace_rs = ReservedSpace(compressed_class_space_size(), 4386 _reserve_alignment, large_pages, addr); 4387 } 4388 } 4389 #endif 4390 // If no successful allocation then try to allocate the space anywhere. If 4391 // that fails then OOM doom. At this point we cannot try allocating the 4392 // metaspace as if UseCompressedClassPointers is off because too much 4393 // initialization has happened that depends on UseCompressedClassPointers. 4394 // So, UseCompressedClassPointers cannot be turned off at this point. 4395 if (!metaspace_rs.is_reserved()) { 4396 metaspace_rs = ReservedSpace(compressed_class_space_size(), 4397 _reserve_alignment, large_pages); 4398 if (!metaspace_rs.is_reserved()) { 4399 vm_exit_during_initialization(err_msg("Could not allocate metaspace: " SIZE_FORMAT " bytes", 4400 compressed_class_space_size())); 4401 } 4402 } 4403 } 4404 4405 // If we got here then the metaspace got allocated. 4406 MemTracker::record_virtual_memory_type((address)metaspace_rs.base(), mtClass); 4407 4408 #if INCLUDE_CDS 4409 // Verify that we can use shared spaces. Otherwise, turn off CDS. 4410 if (UseSharedSpaces && !can_use_cds_with_metaspace_addr(metaspace_rs.base(), cds_base)) { 4411 FileMapInfo::stop_sharing_and_unmap( 4412 "Could not allocate metaspace at a compatible address"); 4413 } 4414 #endif 4415 set_narrow_klass_base_and_shift((address)metaspace_rs.base(), 4416 UseSharedSpaces ? (address)cds_base : 0); 4417 4418 initialize_class_space(metaspace_rs); 4419 4420 LogTarget(Trace, gc, metaspace) lt; 4421 if (lt.is_enabled()) { 4422 ResourceMark rm; 4423 LogStream ls(lt); 4424 print_compressed_class_space(&ls, requested_addr); 4425 ls.cr(); // ~LogStream does not autoflush. 4426 } 4427 } 4428 4429 void Metaspace::print_compressed_class_space(outputStream* st, const char* requested_addr) { 4430 st->print_cr("Narrow klass base: " PTR_FORMAT ", Narrow klass shift: %d", 4431 p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift()); 4432 if (_class_space_list != NULL) { 4433 address base = (address)_class_space_list->current_virtual_space()->bottom(); 4434 st->print("Compressed class space size: " SIZE_FORMAT " Address: " PTR_FORMAT, 4435 compressed_class_space_size(), p2i(base)); 4436 if (requested_addr != 0) { 4437 st->print(" Req Addr: " PTR_FORMAT, p2i(requested_addr)); 4438 } 4439 st->cr(); 4440 } 4441 } 4442 4443 // For UseCompressedClassPointers the class space is reserved above the top of 4444 // the Java heap. The argument passed in is at the base of the compressed space. 4445 void Metaspace::initialize_class_space(ReservedSpace rs) { 4446 // The reserved space size may be bigger because of alignment, esp with UseLargePages 4447 assert(rs.size() >= CompressedClassSpaceSize, 4448 SIZE_FORMAT " != " SIZE_FORMAT, rs.size(), CompressedClassSpaceSize); 4449 assert(using_class_space(), "Must be using class space"); 4450 _class_space_list = new VirtualSpaceList(rs); 4451 _chunk_manager_class = new ChunkManager(true/*is_class*/); 4452 4453 if (!_class_space_list->initialization_succeeded()) { 4454 vm_exit_during_initialization("Failed to setup compressed class space virtual space list."); 4455 } 4456 } 4457 4458 #endif 4459 4460 void Metaspace::ergo_initialize() { 4461 if (DumpSharedSpaces) { 4462 // Using large pages when dumping the shared archive is currently not implemented. 4463 FLAG_SET_ERGO(bool, UseLargePagesInMetaspace, false); 4464 } 4465 4466 size_t page_size = os::vm_page_size(); 4467 if (UseLargePages && UseLargePagesInMetaspace) { 4468 page_size = os::large_page_size(); 4469 } 4470 4471 _commit_alignment = page_size; 4472 _reserve_alignment = MAX2(page_size, (size_t)os::vm_allocation_granularity()); 4473 4474 // Do not use FLAG_SET_ERGO to update MaxMetaspaceSize, since this will 4475 // override if MaxMetaspaceSize was set on the command line or not. 4476 // This information is needed later to conform to the specification of the 4477 // java.lang.management.MemoryUsage API. 4478 // 4479 // Ideally, we would be able to set the default value of MaxMetaspaceSize in 4480 // globals.hpp to the aligned value, but this is not possible, since the 4481 // alignment depends on other flags being parsed. 4482 MaxMetaspaceSize = align_down_bounded(MaxMetaspaceSize, _reserve_alignment); 4483 4484 if (MetaspaceSize > MaxMetaspaceSize) { 4485 MetaspaceSize = MaxMetaspaceSize; 4486 } 4487 4488 MetaspaceSize = align_down_bounded(MetaspaceSize, _commit_alignment); 4489 4490 assert(MetaspaceSize <= MaxMetaspaceSize, "MetaspaceSize should be limited by MaxMetaspaceSize"); 4491 4492 MinMetaspaceExpansion = align_down_bounded(MinMetaspaceExpansion, _commit_alignment); 4493 MaxMetaspaceExpansion = align_down_bounded(MaxMetaspaceExpansion, _commit_alignment); 4494 4495 CompressedClassSpaceSize = align_down_bounded(CompressedClassSpaceSize, _reserve_alignment); 4496 4497 // Initial virtual space size will be calculated at global_initialize() 4498 size_t min_metaspace_sz = 4499 VIRTUALSPACEMULTIPLIER * InitialBootClassLoaderMetaspaceSize; 4500 if (UseCompressedClassPointers) { 4501 if ((min_metaspace_sz + CompressedClassSpaceSize) > MaxMetaspaceSize) { 4502 if (min_metaspace_sz >= MaxMetaspaceSize) { 4503 vm_exit_during_initialization("MaxMetaspaceSize is too small."); 4504 } else { 4505 FLAG_SET_ERGO(size_t, CompressedClassSpaceSize, 4506 MaxMetaspaceSize - min_metaspace_sz); 4507 } 4508 } 4509 } else if (min_metaspace_sz >= MaxMetaspaceSize) { 4510 FLAG_SET_ERGO(size_t, InitialBootClassLoaderMetaspaceSize, 4511 min_metaspace_sz); 4512 } 4513 4514 set_compressed_class_space_size(CompressedClassSpaceSize); 4515 } 4516 4517 void Metaspace::global_initialize() { 4518 MetaspaceGC::initialize(); 4519 4520 #if INCLUDE_CDS 4521 if (DumpSharedSpaces) { 4522 MetaspaceShared::initialize_dumptime_shared_and_meta_spaces(); 4523 } else if (UseSharedSpaces) { 4524 // If any of the archived space fails to map, UseSharedSpaces 4525 // is reset to false. Fall through to the 4526 // (!DumpSharedSpaces && !UseSharedSpaces) case to set up class 4527 // metaspace. 4528 MetaspaceShared::initialize_runtime_shared_and_meta_spaces(); 4529 } 4530 4531 if (!DumpSharedSpaces && !UseSharedSpaces) 4532 #endif // INCLUDE_CDS 4533 { 4534 #ifdef _LP64 4535 if (using_class_space()) { 4536 char* base = (char*)align_up(Universe::heap()->reserved_region().end(), _reserve_alignment); 4537 allocate_metaspace_compressed_klass_ptrs(base, 0); 4538 } 4539 #endif // _LP64 4540 } 4541 4542 // Initialize these before initializing the VirtualSpaceList 4543 _first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord; 4544 _first_chunk_word_size = align_word_size_up(_first_chunk_word_size); 4545 // Make the first class chunk bigger than a medium chunk so it's not put 4546 // on the medium chunk list. The next chunk will be small and progress 4547 // from there. This size calculated by -version. 4548 _first_class_chunk_word_size = MIN2((size_t)MediumChunk*6, 4549 (CompressedClassSpaceSize/BytesPerWord)*2); 4550 _first_class_chunk_word_size = align_word_size_up(_first_class_chunk_word_size); 4551 // Arbitrarily set the initial virtual space to a multiple 4552 // of the boot class loader size. 4553 size_t word_size = VIRTUALSPACEMULTIPLIER * _first_chunk_word_size; 4554 word_size = align_up(word_size, Metaspace::reserve_alignment_words()); 4555 4556 // Initialize the list of virtual spaces. 4557 _space_list = new VirtualSpaceList(word_size); 4558 _chunk_manager_metadata = new ChunkManager(false/*metaspace*/); 4559 4560 if (!_space_list->initialization_succeeded()) { 4561 vm_exit_during_initialization("Unable to setup metadata virtual space list.", NULL); 4562 } 4563 4564 _tracer = new MetaspaceTracer(); 4565 } 4566 4567 void Metaspace::post_initialize() { 4568 MetaspaceGC::post_initialize(); 4569 } 4570 4571 void Metaspace::verify_global_initialization() { 4572 assert(space_list() != NULL, "Metadata VirtualSpaceList has not been initialized"); 4573 assert(chunk_manager_metadata() != NULL, "Metadata ChunkManager has not been initialized"); 4574 4575 if (using_class_space()) { 4576 assert(class_space_list() != NULL, "Class VirtualSpaceList has not been initialized"); 4577 assert(chunk_manager_class() != NULL, "Class ChunkManager has not been initialized"); 4578 } 4579 } 4580 4581 size_t Metaspace::align_word_size_up(size_t word_size) { 4582 size_t byte_size = word_size * wordSize; 4583 return ReservedSpace::allocation_align_size_up(byte_size) / wordSize; 4584 } 4585 4586 MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size, 4587 MetaspaceObj::Type type, TRAPS) { 4588 assert(!_frozen, "sanity"); 4589 if (HAS_PENDING_EXCEPTION) { 4590 assert(false, "Should not allocate with exception pending"); 4591 return NULL; // caller does a CHECK_NULL too 4592 } 4593 4594 assert(loader_data != NULL, "Should never pass around a NULL loader_data. " 4595 "ClassLoaderData::the_null_class_loader_data() should have been used."); 4596 4597 MetadataType mdtype = (type == MetaspaceObj::ClassType) ? ClassType : NonClassType; 4598 4599 // Try to allocate metadata. 4600 MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype); 4601 4602 if (result == NULL) { 4603 tracer()->report_metaspace_allocation_failure(loader_data, word_size, type, mdtype); 4604 4605 // Allocation failed. 4606 if (is_init_completed() && !(DumpSharedSpaces && THREAD->is_VM_thread())) { 4607 // Only start a GC if the bootstrapping has completed. 4608 // Also, we cannot GC if we are at the end of the CDS dumping stage which runs inside 4609 // the VM thread. 4610 4611 // Try to clean out some memory and retry. 4612 result = Universe::heap()->satisfy_failed_metadata_allocation(loader_data, word_size, mdtype); 4613 } 4614 } 4615 4616 if (result == NULL) { 4617 if (DumpSharedSpaces) { 4618 // CDS dumping keeps loading classes, so if we hit an OOM we probably will keep hitting OOM. 4619 // We should abort to avoid generating a potentially bad archive. 4620 tty->print_cr("Failed allocating metaspace object type %s of size " SIZE_FORMAT ". CDS dump aborted.", 4621 MetaspaceObj::type_name(type), word_size * BytesPerWord); 4622 tty->print_cr("Please increase MaxMetaspaceSize (currently " SIZE_FORMAT " bytes).", MaxMetaspaceSize); 4623 vm_exit(1); 4624 } 4625 report_metadata_oome(loader_data, word_size, type, mdtype, CHECK_NULL); 4626 } 4627 4628 // Zero initialize. 4629 Copy::fill_to_words((HeapWord*)result, word_size, 0); 4630 4631 return result; 4632 } 4633 4634 void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, MetadataType mdtype, TRAPS) { 4635 tracer()->report_metadata_oom(loader_data, word_size, type, mdtype); 4636 4637 // If result is still null, we are out of memory. 4638 Log(gc, metaspace, freelist) log; 4639 if (log.is_info()) { 4640 log.info("Metaspace (%s) allocation failed for size " SIZE_FORMAT, 4641 is_class_space_allocation(mdtype) ? "class" : "data", word_size); 4642 ResourceMark rm; 4643 if (log.is_debug()) { 4644 if (loader_data->metaspace_or_null() != NULL) { 4645 LogStream ls(log.debug()); 4646 loader_data->print_value_on(&ls); 4647 ls.cr(); // ~LogStream does not autoflush. 4648 } 4649 } 4650 LogStream ls(log.info()); 4651 // In case of an OOM, log out a short but still useful report. 4652 MetaspaceUtils::print_basic_report(&ls, 0); 4653 ls.cr(); // ~LogStream does not autoflush. 4654 } 4655 4656 bool out_of_compressed_class_space = false; 4657 if (is_class_space_allocation(mdtype)) { 4658 ClassLoaderMetaspace* metaspace = loader_data->metaspace_non_null(); 4659 out_of_compressed_class_space = 4660 MetaspaceUtils::committed_bytes(Metaspace::ClassType) + 4661 (metaspace->class_chunk_size(word_size) * BytesPerWord) > 4662 CompressedClassSpaceSize; 4663 } 4664 4665 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support 4666 const char* space_string = out_of_compressed_class_space ? 4667 "Compressed class space" : "Metaspace"; 4668 4669 report_java_out_of_memory(space_string); 4670 4671 if (JvmtiExport::should_post_resource_exhausted()) { 4672 JvmtiExport::post_resource_exhausted( 4673 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR, 4674 space_string); 4675 } 4676 4677 if (!is_init_completed()) { 4678 vm_exit_during_initialization("OutOfMemoryError", space_string); 4679 } 4680 4681 if (out_of_compressed_class_space) { 4682 THROW_OOP(Universe::out_of_memory_error_class_metaspace()); 4683 } else { 4684 THROW_OOP(Universe::out_of_memory_error_metaspace()); 4685 } 4686 } 4687 4688 const char* Metaspace::metadata_type_name(Metaspace::MetadataType mdtype) { 4689 switch (mdtype) { 4690 case Metaspace::ClassType: return "Class"; 4691 case Metaspace::NonClassType: return "Metadata"; 4692 default: 4693 assert(false, "Got bad mdtype: %d", (int) mdtype); 4694 return NULL; 4695 } 4696 } 4697 4698 void Metaspace::purge(MetadataType mdtype) { 4699 get_space_list(mdtype)->purge(get_chunk_manager(mdtype)); 4700 } 4701 4702 void Metaspace::purge() { 4703 MutexLockerEx cl(MetaspaceExpand_lock, 4704 Mutex::_no_safepoint_check_flag); 4705 purge(NonClassType); 4706 if (using_class_space()) { 4707 purge(ClassType); 4708 } 4709 } 4710 4711 bool Metaspace::contains(const void* ptr) { 4712 if (MetaspaceShared::is_in_shared_metaspace(ptr)) { 4713 return true; 4714 } 4715 return contains_non_shared(ptr); 4716 } 4717 4718 bool Metaspace::contains_non_shared(const void* ptr) { 4719 if (using_class_space() && get_space_list(ClassType)->contains(ptr)) { 4720 return true; 4721 } 4722 4723 return get_space_list(NonClassType)->contains(ptr); 4724 } 4725 4726 // ClassLoaderMetaspace 4727 4728 ClassLoaderMetaspace::ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type) 4729 : _lock(lock) 4730 , _space_type(type) 4731 , _vsm(NULL) 4732 , _class_vsm(NULL) 4733 { 4734 initialize(lock, type); 4735 } 4736 4737 ClassLoaderMetaspace::~ClassLoaderMetaspace() { 4738 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_metaspace_deaths)); 4739 delete _vsm; 4740 if (Metaspace::using_class_space()) { 4741 delete _class_vsm; 4742 } 4743 } 4744 4745 void ClassLoaderMetaspace::initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype) { 4746 Metachunk* chunk = get_initialization_chunk(type, mdtype); 4747 if (chunk != NULL) { 4748 // Add to this manager's list of chunks in use and make it the current_chunk(). 4749 get_space_manager(mdtype)->add_chunk(chunk, true); 4750 } 4751 } 4752 4753 Metachunk* ClassLoaderMetaspace::get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype) { 4754 size_t chunk_word_size = get_space_manager(mdtype)->get_initial_chunk_size(type); 4755 4756 // Get a chunk from the chunk freelist 4757 Metachunk* chunk = Metaspace::get_chunk_manager(mdtype)->chunk_freelist_allocate(chunk_word_size); 4758 4759 if (chunk == NULL) { 4760 chunk = Metaspace::get_space_list(mdtype)->get_new_chunk(chunk_word_size, 4761 get_space_manager(mdtype)->medium_chunk_bunch()); 4762 } 4763 4764 return chunk; 4765 } 4766 4767 void ClassLoaderMetaspace::initialize(Mutex* lock, Metaspace::MetaspaceType type) { 4768 Metaspace::verify_global_initialization(); 4769 4770 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_metaspace_births)); 4771 4772 // Allocate SpaceManager for metadata objects. 4773 _vsm = new SpaceManager(Metaspace::NonClassType, type, lock); 4774 4775 if (Metaspace::using_class_space()) { 4776 // Allocate SpaceManager for classes. 4777 _class_vsm = new SpaceManager(Metaspace::ClassType, type, lock); 4778 } 4779 4780 MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag); 4781 4782 // Allocate chunk for metadata objects 4783 initialize_first_chunk(type, Metaspace::NonClassType); 4784 4785 // Allocate chunk for class metadata objects 4786 if (Metaspace::using_class_space()) { 4787 initialize_first_chunk(type, Metaspace::ClassType); 4788 } 4789 } 4790 4791 MetaWord* ClassLoaderMetaspace::allocate(size_t word_size, Metaspace::MetadataType mdtype) { 4792 Metaspace::assert_not_frozen(); 4793 4794 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_allocs)); 4795 4796 // Don't use class_vsm() unless UseCompressedClassPointers is true. 4797 if (Metaspace::is_class_space_allocation(mdtype)) { 4798 return class_vsm()->allocate(word_size); 4799 } else { 4800 return vsm()->allocate(word_size); 4801 } 4802 } 4803 4804 MetaWord* ClassLoaderMetaspace::expand_and_allocate(size_t word_size, Metaspace::MetadataType mdtype) { 4805 Metaspace::assert_not_frozen(); 4806 size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size * BytesPerWord); 4807 assert(delta_bytes > 0, "Must be"); 4808 4809 size_t before = 0; 4810 size_t after = 0; 4811 MetaWord* res; 4812 bool incremented; 4813 4814 // Each thread increments the HWM at most once. Even if the thread fails to increment 4815 // the HWM, an allocation is still attempted. This is because another thread must then 4816 // have incremented the HWM and therefore the allocation might still succeed. 4817 do { 4818 incremented = MetaspaceGC::inc_capacity_until_GC(delta_bytes, &after, &before); 4819 res = allocate(word_size, mdtype); 4820 } while (!incremented && res == NULL); 4821 4822 if (incremented) { 4823 Metaspace::tracer()->report_gc_threshold(before, after, 4824 MetaspaceGCThresholdUpdater::ExpandAndAllocate); 4825 log_trace(gc, metaspace)("Increase capacity to GC from " SIZE_FORMAT " to " SIZE_FORMAT, before, after); 4826 } 4827 4828 return res; 4829 } 4830 4831 size_t ClassLoaderMetaspace::allocated_blocks_bytes() const { 4832 return (vsm()->used_words() + 4833 (Metaspace::using_class_space() ? class_vsm()->used_words() : 0)) * BytesPerWord; 4834 } 4835 4836 size_t ClassLoaderMetaspace::allocated_chunks_bytes() const { 4837 return (vsm()->capacity_words() + 4838 (Metaspace::using_class_space() ? class_vsm()->capacity_words() : 0)) * BytesPerWord; 4839 } 4840 4841 void ClassLoaderMetaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) { 4842 Metaspace::assert_not_frozen(); 4843 assert(!SafepointSynchronize::is_at_safepoint() 4844 || Thread::current()->is_VM_thread(), "should be the VM thread"); 4845 4846 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_external_deallocs)); 4847 4848 MutexLockerEx ml(vsm()->lock(), Mutex::_no_safepoint_check_flag); 4849 4850 if (is_class && Metaspace::using_class_space()) { 4851 class_vsm()->deallocate(ptr, word_size); 4852 } else { 4853 vsm()->deallocate(ptr, word_size); 4854 } 4855 } 4856 4857 size_t ClassLoaderMetaspace::class_chunk_size(size_t word_size) { 4858 assert(Metaspace::using_class_space(), "Has to use class space"); 4859 return class_vsm()->calc_chunk_size(word_size); 4860 } 4861 4862 void ClassLoaderMetaspace::print_on(outputStream* out) const { 4863 // Print both class virtual space counts and metaspace. 4864 if (Verbose) { 4865 vsm()->print_on(out); 4866 if (Metaspace::using_class_space()) { 4867 class_vsm()->print_on(out); 4868 } 4869 } 4870 } 4871 4872 void ClassLoaderMetaspace::verify() { 4873 vsm()->verify(); 4874 if (Metaspace::using_class_space()) { 4875 class_vsm()->verify(); 4876 } 4877 } 4878 4879 void ClassLoaderMetaspace::add_to_statistics_locked(ClassLoaderMetaspaceStatistics* out) const { 4880 assert_lock_strong(lock()); 4881 vsm()->add_to_statistics_locked(&out->nonclass_sm_stats()); 4882 if (Metaspace::using_class_space()) { 4883 class_vsm()->add_to_statistics_locked(&out->class_sm_stats()); 4884 } 4885 } 4886 4887 void ClassLoaderMetaspace::add_to_statistics(ClassLoaderMetaspaceStatistics* out) const { 4888 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 4889 add_to_statistics_locked(out); 4890 } 4891 4892 #ifdef ASSERT 4893 static void do_verify_chunk(Metachunk* chunk) { 4894 guarantee(chunk != NULL, "Sanity"); 4895 // Verify chunk itself; then verify that it is consistent with the 4896 // occupany map of its containing node. 4897 chunk->verify(); 4898 VirtualSpaceNode* const vsn = chunk->container(); 4899 OccupancyMap* const ocmap = vsn->occupancy_map(); 4900 ocmap->verify_for_chunk(chunk); 4901 } 4902 #endif 4903 4904 static void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse) { 4905 chunk->set_is_tagged_free(!inuse); 4906 OccupancyMap* const ocmap = chunk->container()->occupancy_map(); 4907 ocmap->set_region_in_use((MetaWord*)chunk, chunk->word_size(), inuse); 4908 } 4909 4910 /////////////// Unit tests /////////////// 4911 4912 #ifndef PRODUCT 4913 4914 class TestMetaspaceUtilsTest : AllStatic { 4915 public: 4916 static void test_reserved() { 4917 size_t reserved = MetaspaceUtils::reserved_bytes(); 4918 4919 assert(reserved > 0, "assert"); 4920 4921 size_t committed = MetaspaceUtils::committed_bytes(); 4922 assert(committed <= reserved, "assert"); 4923 4924 size_t reserved_metadata = MetaspaceUtils::reserved_bytes(Metaspace::NonClassType); 4925 assert(reserved_metadata > 0, "assert"); 4926 assert(reserved_metadata <= reserved, "assert"); 4927 4928 if (UseCompressedClassPointers) { 4929 size_t reserved_class = MetaspaceUtils::reserved_bytes(Metaspace::ClassType); 4930 assert(reserved_class > 0, "assert"); 4931 assert(reserved_class < reserved, "assert"); 4932 } 4933 } 4934 4935 static void test_committed() { 4936 size_t committed = MetaspaceUtils::committed_bytes(); 4937 4938 assert(committed > 0, "assert"); 4939 4940 size_t reserved = MetaspaceUtils::reserved_bytes(); 4941 assert(committed <= reserved, "assert"); 4942 4943 size_t committed_metadata = MetaspaceUtils::committed_bytes(Metaspace::NonClassType); 4944 assert(committed_metadata > 0, "assert"); 4945 assert(committed_metadata <= committed, "assert"); 4946 4947 if (UseCompressedClassPointers) { 4948 size_t committed_class = MetaspaceUtils::committed_bytes(Metaspace::ClassType); 4949 assert(committed_class > 0, "assert"); 4950 assert(committed_class < committed, "assert"); 4951 } 4952 } 4953 4954 static void test_virtual_space_list_large_chunk() { 4955 VirtualSpaceList* vs_list = new VirtualSpaceList(os::vm_allocation_granularity()); 4956 MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag); 4957 // A size larger than VirtualSpaceSize (256k) and add one page to make it _not_ be 4958 // vm_allocation_granularity aligned on Windows. 4959 size_t large_size = (size_t)(2*256*K + (os::vm_page_size()/BytesPerWord)); 4960 large_size += (os::vm_page_size()/BytesPerWord); 4961 vs_list->get_new_chunk(large_size, 0); 4962 } 4963 4964 static void test() { 4965 test_reserved(); 4966 test_committed(); 4967 test_virtual_space_list_large_chunk(); 4968 } 4969 }; 4970 4971 void TestMetaspaceUtils_test() { 4972 TestMetaspaceUtilsTest::test(); 4973 } 4974 4975 class TestVirtualSpaceNodeTest { 4976 static void chunk_up(size_t words_left, size_t& num_medium_chunks, 4977 size_t& num_small_chunks, 4978 size_t& num_specialized_chunks) { 4979 num_medium_chunks = words_left / MediumChunk; 4980 words_left = words_left % MediumChunk; 4981 4982 num_small_chunks = words_left / SmallChunk; 4983 words_left = words_left % SmallChunk; 4984 // how many specialized chunks can we get? 4985 num_specialized_chunks = words_left / SpecializedChunk; 4986 assert(words_left % SpecializedChunk == 0, "should be nothing left"); 4987 } 4988 4989 public: 4990 static void test() { 4991 MutexLockerEx ml(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag); 4992 const size_t vsn_test_size_words = MediumChunk * 4; 4993 const size_t vsn_test_size_bytes = vsn_test_size_words * BytesPerWord; 4994 4995 // The chunk sizes must be multiples of eachother, or this will fail 4996 STATIC_ASSERT(MediumChunk % SmallChunk == 0); 4997 STATIC_ASSERT(SmallChunk % SpecializedChunk == 0); 4998 4999 { // No committed memory in VSN 5000 ChunkManager cm(false); 5001 VirtualSpaceNode vsn(false, vsn_test_size_bytes); 5002 vsn.initialize(); 5003 vsn.retire(&cm); 5004 assert(cm.sum_free_chunks_count() == 0, "did not commit any memory in the VSN"); 5005 } 5006 5007 { // All of VSN is committed, half is used by chunks 5008 ChunkManager cm(false); 5009 VirtualSpaceNode vsn(false, vsn_test_size_bytes); 5010 vsn.initialize(); 5011 vsn.expand_by(vsn_test_size_words, vsn_test_size_words); 5012 vsn.get_chunk_vs(MediumChunk); 5013 vsn.get_chunk_vs(MediumChunk); 5014 vsn.retire(&cm); 5015 assert(cm.sum_free_chunks_count() == 2, "should have been memory left for 2 medium chunks"); 5016 assert(cm.sum_free_chunks() == 2*MediumChunk, "sizes should add up"); 5017 } 5018 5019 const size_t page_chunks = 4 * (size_t)os::vm_page_size() / BytesPerWord; 5020 // This doesn't work for systems with vm_page_size >= 16K. 5021 if (page_chunks < MediumChunk) { 5022 // 4 pages of VSN is committed, some is used by chunks 5023 ChunkManager cm(false); 5024 VirtualSpaceNode vsn(false, vsn_test_size_bytes); 5025 5026 vsn.initialize(); 5027 vsn.expand_by(page_chunks, page_chunks); 5028 vsn.get_chunk_vs(SmallChunk); 5029 vsn.get_chunk_vs(SpecializedChunk); 5030 vsn.retire(&cm); 5031 5032 // committed - used = words left to retire 5033 const size_t words_left = page_chunks - SmallChunk - SpecializedChunk; 5034 5035 size_t num_medium_chunks, num_small_chunks, num_spec_chunks; 5036 chunk_up(words_left, num_medium_chunks, num_small_chunks, num_spec_chunks); 5037 5038 assert(num_medium_chunks == 0, "should not get any medium chunks"); 5039 assert(cm.sum_free_chunks_count() == (num_small_chunks + num_spec_chunks), "should be space for 3 chunks"); 5040 assert(cm.sum_free_chunks() == words_left, "sizes should add up"); 5041 } 5042 5043 { // Half of VSN is committed, a humongous chunk is used 5044 ChunkManager cm(false); 5045 VirtualSpaceNode vsn(false, vsn_test_size_bytes); 5046 vsn.initialize(); 5047 vsn.expand_by(MediumChunk * 2, MediumChunk * 2); 5048 vsn.get_chunk_vs(MediumChunk + SpecializedChunk); // Humongous chunks will be aligned up to MediumChunk + SpecializedChunk 5049 vsn.retire(&cm); 5050 5051 const size_t words_left = MediumChunk * 2 - (MediumChunk + SpecializedChunk); 5052 size_t num_medium_chunks, num_small_chunks, num_spec_chunks; 5053 chunk_up(words_left, num_medium_chunks, num_small_chunks, num_spec_chunks); 5054 5055 assert(num_medium_chunks == 0, "should not get any medium chunks"); 5056 assert(cm.sum_free_chunks_count() == (num_small_chunks + num_spec_chunks), "should be space for 3 chunks"); 5057 assert(cm.sum_free_chunks() == words_left, "sizes should add up"); 5058 } 5059 5060 } 5061 5062 #define assert_is_available_positive(word_size) \ 5063 assert(vsn.is_available(word_size), \ 5064 #word_size ": " PTR_FORMAT " bytes were not available in " \ 5065 "VirtualSpaceNode [" PTR_FORMAT ", " PTR_FORMAT ")", \ 5066 (uintptr_t)(word_size * BytesPerWord), p2i(vsn.bottom()), p2i(vsn.end())); 5067 5068 #define assert_is_available_negative(word_size) \ 5069 assert(!vsn.is_available(word_size), \ 5070 #word_size ": " PTR_FORMAT " bytes should not be available in " \ 5071 "VirtualSpaceNode [" PTR_FORMAT ", " PTR_FORMAT ")", \ 5072 (uintptr_t)(word_size * BytesPerWord), p2i(vsn.bottom()), p2i(vsn.end())); 5073 5074 static void test_is_available_positive() { 5075 // Reserve some memory. 5076 VirtualSpaceNode vsn(false, os::vm_allocation_granularity()); 5077 assert(vsn.initialize(), "Failed to setup VirtualSpaceNode"); 5078 5079 // Commit some memory. 5080 size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord; 5081 bool expanded = vsn.expand_by(commit_word_size, commit_word_size); 5082 assert(expanded, "Failed to commit"); 5083 5084 // Check that is_available accepts the committed size. 5085 assert_is_available_positive(commit_word_size); 5086 5087 // Check that is_available accepts half the committed size. 5088 size_t expand_word_size = commit_word_size / 2; 5089 assert_is_available_positive(expand_word_size); 5090 } 5091 5092 static void test_is_available_negative() { 5093 // Reserve some memory. 5094 VirtualSpaceNode vsn(false, os::vm_allocation_granularity()); 5095 assert(vsn.initialize(), "Failed to setup VirtualSpaceNode"); 5096 5097 // Commit some memory. 5098 size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord; 5099 bool expanded = vsn.expand_by(commit_word_size, commit_word_size); 5100 assert(expanded, "Failed to commit"); 5101 5102 // Check that is_available doesn't accept a too large size. 5103 size_t two_times_commit_word_size = commit_word_size * 2; 5104 assert_is_available_negative(two_times_commit_word_size); 5105 } 5106 5107 static void test_is_available_overflow() { 5108 // Reserve some memory. 5109 VirtualSpaceNode vsn(false, os::vm_allocation_granularity()); 5110 assert(vsn.initialize(), "Failed to setup VirtualSpaceNode"); 5111 5112 // Commit some memory. 5113 size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord; 5114 bool expanded = vsn.expand_by(commit_word_size, commit_word_size); 5115 assert(expanded, "Failed to commit"); 5116 5117 // Calculate a size that will overflow the virtual space size. 5118 void* virtual_space_max = (void*)(uintptr_t)-1; 5119 size_t bottom_to_max = pointer_delta(virtual_space_max, vsn.bottom(), 1); 5120 size_t overflow_size = bottom_to_max + BytesPerWord; 5121 size_t overflow_word_size = overflow_size / BytesPerWord; 5122 5123 // Check that is_available can handle the overflow. 5124 assert_is_available_negative(overflow_word_size); 5125 } 5126 5127 static void test_is_available() { 5128 TestVirtualSpaceNodeTest::test_is_available_positive(); 5129 TestVirtualSpaceNodeTest::test_is_available_negative(); 5130 TestVirtualSpaceNodeTest::test_is_available_overflow(); 5131 } 5132 }; 5133 5134 // The following test is placed here instead of a gtest / unittest file 5135 // because the ChunkManager class is only available in this file. 5136 void ChunkManager_test_list_index() { 5137 { 5138 // Test previous bug where a query for a humongous class metachunk, 5139 // incorrectly matched the non-class medium metachunk size. 5140 { 5141 ChunkManager manager(true); 5142 5143 assert(MediumChunk > ClassMediumChunk, "Precondition for test"); 5144 5145 ChunkIndex index = manager.list_index(MediumChunk); 5146 5147 assert(index == HumongousIndex, 5148 "Requested size is larger than ClassMediumChunk," 5149 " so should return HumongousIndex. Got index: %d", (int)index); 5150 } 5151 5152 // Check the specified sizes as well. 5153 { 5154 ChunkManager manager(true); 5155 assert(manager.list_index(ClassSpecializedChunk) == SpecializedIndex, "sanity"); 5156 assert(manager.list_index(ClassSmallChunk) == SmallIndex, "sanity"); 5157 assert(manager.list_index(ClassMediumChunk) == MediumIndex, "sanity"); 5158 assert(manager.list_index(ClassMediumChunk + ClassSpecializedChunk) == HumongousIndex, "sanity"); 5159 } 5160 { 5161 ChunkManager manager(false); 5162 assert(manager.list_index(SpecializedChunk) == SpecializedIndex, "sanity"); 5163 assert(manager.list_index(SmallChunk) == SmallIndex, "sanity"); 5164 assert(manager.list_index(MediumChunk) == MediumIndex, "sanity"); 5165 assert(manager.list_index(MediumChunk + SpecializedChunk) == HumongousIndex, "sanity"); 5166 } 5167 5168 } 5169 5170 } 5171 5172 #endif // !PRODUCT 5173 5174 #ifdef ASSERT 5175 5176 // The following test is placed here instead of a gtest / unittest file 5177 // because the ChunkManager class is only available in this file. 5178 class SpaceManagerTest : AllStatic { 5179 friend void SpaceManager_test_adjust_initial_chunk_size(); 5180 5181 static void test_adjust_initial_chunk_size(bool is_class) { 5182 const size_t smallest = SpaceManager::smallest_chunk_size(is_class); 5183 const size_t normal = SpaceManager::small_chunk_size(is_class); 5184 const size_t medium = SpaceManager::medium_chunk_size(is_class); 5185 5186 #define test_adjust_initial_chunk_size(value, expected, is_class_value) \ 5187 do { \ 5188 size_t v = value; \ 5189 size_t e = expected; \ 5190 assert(SpaceManager::adjust_initial_chunk_size(v, (is_class_value)) == e, \ 5191 "Expected: " SIZE_FORMAT " got: " SIZE_FORMAT, e, v); \ 5192 } while (0) 5193 5194 // Smallest (specialized) 5195 test_adjust_initial_chunk_size(1, smallest, is_class); 5196 test_adjust_initial_chunk_size(smallest - 1, smallest, is_class); 5197 test_adjust_initial_chunk_size(smallest, smallest, is_class); 5198 5199 // Small 5200 test_adjust_initial_chunk_size(smallest + 1, normal, is_class); 5201 test_adjust_initial_chunk_size(normal - 1, normal, is_class); 5202 test_adjust_initial_chunk_size(normal, normal, is_class); 5203 5204 // Medium 5205 test_adjust_initial_chunk_size(normal + 1, medium, is_class); 5206 test_adjust_initial_chunk_size(medium - 1, medium, is_class); 5207 test_adjust_initial_chunk_size(medium, medium, is_class); 5208 5209 // Humongous 5210 test_adjust_initial_chunk_size(medium + 1, medium + 1, is_class); 5211 5212 #undef test_adjust_initial_chunk_size 5213 } 5214 5215 static void test_adjust_initial_chunk_size() { 5216 test_adjust_initial_chunk_size(false); 5217 test_adjust_initial_chunk_size(true); 5218 } 5219 }; 5220 5221 void SpaceManager_test_adjust_initial_chunk_size() { 5222 SpaceManagerTest::test_adjust_initial_chunk_size(); 5223 } 5224 5225 #endif // ASSERT 5226 5227 struct chunkmanager_statistics_t { 5228 int num_specialized_chunks; 5229 int num_small_chunks; 5230 int num_medium_chunks; 5231 int num_humongous_chunks; 5232 }; 5233 5234 extern void test_metaspace_retrieve_chunkmanager_statistics(Metaspace::MetadataType mdType, chunkmanager_statistics_t* out) { 5235 ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(mdType); 5236 ChunkManagerStatistics stat; 5237 chunk_manager->collect_statistics(&stat); 5238 out->num_specialized_chunks = (int)stat.chunk_stats(SpecializedIndex).num(); 5239 out->num_small_chunks = (int)stat.chunk_stats(SmallIndex).num(); 5240 out->num_medium_chunks = (int)stat.chunk_stats(MediumIndex).num(); 5241 out->num_humongous_chunks = (int)stat.chunk_stats(HumongousIndex).num(); 5242 } 5243 5244 struct chunk_geometry_t { 5245 size_t specialized_chunk_word_size; 5246 size_t small_chunk_word_size; 5247 size_t medium_chunk_word_size; 5248 }; 5249 5250 extern void test_metaspace_retrieve_chunk_geometry(Metaspace::MetadataType mdType, chunk_geometry_t* out) { 5251 if (mdType == Metaspace::NonClassType) { 5252 out->specialized_chunk_word_size = SpecializedChunk; 5253 out->small_chunk_word_size = SmallChunk; 5254 out->medium_chunk_word_size = MediumChunk; 5255 } else { 5256 out->specialized_chunk_word_size = ClassSpecializedChunk; 5257 out->small_chunk_word_size = ClassSmallChunk; 5258 out->medium_chunk_word_size = ClassMediumChunk; 5259 } 5260 }