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 "gc/shared/gcLocker.hpp" 29 #include "logging/log.hpp" 30 #include "logging/logStream.hpp" 31 #include "memory/allocation.hpp" 32 #include "memory/binaryTreeDictionary.hpp" 33 #include "memory/filemap.hpp" 34 #include "memory/freeList.hpp" 35 #include "memory/metachunk.hpp" 36 #include "memory/metaspace.hpp" 37 #include "memory/metaspaceGCThresholdUpdater.hpp" 38 #include "memory/metaspaceShared.hpp" 39 #include "memory/metaspaceTracer.hpp" 40 #include "memory/resourceArea.hpp" 41 #include "memory/universe.hpp" 42 #include "runtime/atomic.hpp" 43 #include "runtime/globals.hpp" 44 #include "runtime/init.hpp" 45 #include "runtime/java.hpp" 46 #include "runtime/mutex.hpp" 47 #include "runtime/orderAccess.inline.hpp" 48 #include "services/memTracker.hpp" 49 #include "services/memoryService.hpp" 50 #include "utilities/align.hpp" 51 #include "utilities/copy.hpp" 52 #include "utilities/debug.hpp" 53 #include "utilities/macros.hpp" 54 55 typedef BinaryTreeDictionary<Metablock, FreeList<Metablock> > BlockTreeDictionary; 56 typedef BinaryTreeDictionary<Metachunk, FreeList<Metachunk> > ChunkTreeDictionary; 57 58 // Set this constant to enable slow integrity checking of the free chunk lists 59 const bool metaspace_slow_verify = false; 60 61 // Helper function that does a bunch of checks for a chunk. 62 DEBUG_ONLY(static void do_verify_chunk(Metachunk* chunk);) 63 64 // Given a Metachunk, update its in-use information (both in the 65 // chunk and the occupancy map). 66 static void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse); 67 68 size_t const allocation_from_dictionary_limit = 4 * K; 69 70 MetaWord* last_allocated = 0; 71 72 size_t Metaspace::_compressed_class_space_size; 73 const MetaspaceTracer* Metaspace::_tracer = NULL; 74 75 DEBUG_ONLY(bool Metaspace::_frozen = false;) 76 77 enum ChunkSizes { // in words. 78 ClassSpecializedChunk = 128, 79 SpecializedChunk = 128, 80 ClassSmallChunk = 256, 81 SmallChunk = 512, 82 ClassMediumChunk = 4 * K, 83 MediumChunk = 8 * K 84 }; 85 86 // Returns size of this chunk type. 87 size_t get_size_for_nonhumongous_chunktype(ChunkIndex chunktype, bool is_class) { 88 assert(is_valid_nonhumongous_chunktype(chunktype), "invalid chunk type."); 89 size_t size = 0; 90 if (is_class) { 91 switch(chunktype) { 92 case SpecializedIndex: size = ClassSpecializedChunk; break; 93 case SmallIndex: size = ClassSmallChunk; break; 94 case MediumIndex: size = ClassMediumChunk; break; 95 default: 96 ShouldNotReachHere(); 97 } 98 } else { 99 switch(chunktype) { 100 case SpecializedIndex: size = SpecializedChunk; break; 101 case SmallIndex: size = SmallChunk; break; 102 case MediumIndex: size = MediumChunk; break; 103 default: 104 ShouldNotReachHere(); 105 } 106 } 107 return size; 108 } 109 110 ChunkIndex get_chunk_type_by_size(size_t size, bool is_class) { 111 if (is_class) { 112 if (size == ClassSpecializedChunk) { 113 return SpecializedIndex; 114 } else if (size == ClassSmallChunk) { 115 return SmallIndex; 116 } else if (size == ClassMediumChunk) { 117 return MediumIndex; 118 } else if (size > ClassMediumChunk) { 119 assert(is_aligned(size, ClassSpecializedChunk), "Invalid chunk size"); 120 return HumongousIndex; 121 } 122 } else { 123 if (size == SpecializedChunk) { 124 return SpecializedIndex; 125 } else if (size == SmallChunk) { 126 return SmallIndex; 127 } else if (size == MediumChunk) { 128 return MediumIndex; 129 } else if (size > MediumChunk) { 130 assert(is_aligned(size, SpecializedChunk), "Invalid chunk size"); 131 return HumongousIndex; 132 } 133 } 134 ShouldNotReachHere(); 135 return (ChunkIndex)-1; 136 } 137 138 139 static ChunkIndex next_chunk_index(ChunkIndex i) { 140 assert(i < NumberOfInUseLists, "Out of bound"); 141 return (ChunkIndex) (i+1); 142 } 143 144 static ChunkIndex prev_chunk_index(ChunkIndex i) { 145 assert(i > ZeroIndex, "Out of bound"); 146 return (ChunkIndex) (i-1); 147 } 148 149 static const char* scale_unit(size_t scale) { 150 switch(scale) { 151 case 1: return "BYTES"; 152 case K: return "KB"; 153 case M: return "MB"; 154 case G: return "GB"; 155 default: 156 ShouldNotReachHere(); 157 return NULL; 158 } 159 } 160 161 volatile intptr_t MetaspaceGC::_capacity_until_GC = 0; 162 uint MetaspaceGC::_shrink_factor = 0; 163 bool MetaspaceGC::_should_concurrent_collect = false; 164 165 typedef class FreeList<Metachunk> ChunkList; 166 167 // Manages the global free lists of chunks. 168 class ChunkManager : public CHeapObj<mtInternal> { 169 friend class TestVirtualSpaceNodeTest; 170 171 // Free list of chunks of different sizes. 172 // SpecializedChunk 173 // SmallChunk 174 // MediumChunk 175 ChunkList _free_chunks[NumberOfFreeLists]; 176 177 // Whether or not this is the class chunkmanager. 178 const bool _is_class; 179 180 // Return non-humongous chunk list by its index. 181 ChunkList* free_chunks(ChunkIndex index); 182 183 // Returns non-humongous chunk list for the given chunk word size. 184 ChunkList* find_free_chunks_list(size_t word_size); 185 186 // HumongousChunk 187 ChunkTreeDictionary _humongous_dictionary; 188 189 // Returns the humongous chunk dictionary. 190 ChunkTreeDictionary* humongous_dictionary() { 191 return &_humongous_dictionary; 192 } 193 194 // Size, in metaspace words, of all chunks managed by this ChunkManager 195 size_t _free_chunks_total; 196 // Number of chunks in this ChunkManager 197 size_t _free_chunks_count; 198 199 // Update counters after a chunk was added or removed removed. 200 void account_for_added_chunk(const Metachunk* c); 201 void account_for_removed_chunk(const Metachunk* c); 202 203 // Debug support 204 205 size_t sum_free_chunks(); 206 size_t sum_free_chunks_count(); 207 208 void locked_verify_free_chunks_total(); 209 void slow_locked_verify_free_chunks_total() { 210 if (metaspace_slow_verify) { 211 locked_verify_free_chunks_total(); 212 } 213 } 214 void locked_verify_free_chunks_count(); 215 void slow_locked_verify_free_chunks_count() { 216 if (metaspace_slow_verify) { 217 locked_verify_free_chunks_count(); 218 } 219 } 220 void verify_free_chunks_count(); 221 222 // Given a pointer to a chunk, attempts to merge it with neighboring 223 // free chunks to form a bigger chunk. Returns true if successful. 224 bool attempt_to_coalesce_around_chunk(Metachunk* chunk, ChunkIndex target_chunk_type); 225 226 // Helper for chunk merging: 227 // Given an address range with 1-n chunks which are all supposed to be 228 // free and hence currently managed by this ChunkManager, remove them 229 // from this ChunkManager and mark them as invalid. 230 // - This does not correct the occupancy map. 231 // - This does not adjust the counters in ChunkManager. 232 // - Does not adjust container count counter in containing VirtualSpaceNode. 233 // Returns number of chunks removed. 234 int remove_chunks_in_area(MetaWord* p, size_t word_size); 235 236 // Helper for chunk splitting: given a target chunk size and a larger free chunk, 237 // split up the larger chunk into n smaller chunks, at least one of which should be 238 // the target chunk of target chunk size. The smaller chunks, including the target 239 // chunk, are returned to the freelist. The pointer to the target chunk is returned. 240 // Note that this chunk is supposed to be removed from the freelist right away. 241 Metachunk* split_chunk(size_t target_chunk_word_size, Metachunk* chunk); 242 243 public: 244 245 struct ChunkManagerStatistics { 246 size_t num_by_type[NumberOfFreeLists]; 247 size_t single_size_by_type[NumberOfFreeLists]; 248 size_t total_size_by_type[NumberOfFreeLists]; 249 size_t num_humongous_chunks; 250 size_t total_size_humongous_chunks; 251 }; 252 253 void locked_get_statistics(ChunkManagerStatistics* stat) const; 254 void get_statistics(ChunkManagerStatistics* stat) const; 255 static void print_statistics(const ChunkManagerStatistics* stat, outputStream* out, size_t scale); 256 257 258 ChunkManager(bool is_class) 259 : _is_class(is_class), _free_chunks_total(0), _free_chunks_count(0) { 260 _free_chunks[SpecializedIndex].set_size(get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class)); 261 _free_chunks[SmallIndex].set_size(get_size_for_nonhumongous_chunktype(SmallIndex, is_class)); 262 _free_chunks[MediumIndex].set_size(get_size_for_nonhumongous_chunktype(MediumIndex, is_class)); 263 } 264 265 // Add or delete (return) a chunk to the global freelist. 266 Metachunk* chunk_freelist_allocate(size_t word_size); 267 268 // Map a size to a list index assuming that there are lists 269 // for special, small, medium, and humongous chunks. 270 ChunkIndex list_index(size_t size); 271 272 // Map a given index to the chunk size. 273 size_t size_by_index(ChunkIndex index) const; 274 275 bool is_class() const { return _is_class; } 276 277 // Convenience accessors. 278 size_t medium_chunk_word_size() const { return size_by_index(MediumIndex); } 279 size_t small_chunk_word_size() const { return size_by_index(SmallIndex); } 280 size_t specialized_chunk_word_size() const { return size_by_index(SpecializedIndex); } 281 282 // Take a chunk from the ChunkManager. The chunk is expected to be in 283 // the chunk manager (the freelist if non-humongous, the dictionary if 284 // humongous). 285 void remove_chunk(Metachunk* chunk); 286 287 // Return a single chunk of type index to the ChunkManager. 288 void return_single_chunk(ChunkIndex index, Metachunk* chunk); 289 290 // Add the simple linked list of chunks to the freelist of chunks 291 // of type index. 292 void return_chunk_list(ChunkIndex index, Metachunk* chunk); 293 294 // Total of the space in the free chunks list 295 size_t free_chunks_total_words(); 296 size_t free_chunks_total_bytes(); 297 298 // Number of chunks in the free chunks list 299 size_t free_chunks_count(); 300 301 // Remove from a list by size. Selects list based on size of chunk. 302 Metachunk* free_chunks_get(size_t chunk_word_size); 303 304 #define index_bounds_check(index) \ 305 assert(index == SpecializedIndex || \ 306 index == SmallIndex || \ 307 index == MediumIndex || \ 308 index == HumongousIndex, "Bad index: %d", (int) index) 309 310 size_t num_free_chunks(ChunkIndex index) const { 311 index_bounds_check(index); 312 313 if (index == HumongousIndex) { 314 return _humongous_dictionary.total_free_blocks(); 315 } 316 317 ssize_t count = _free_chunks[index].count(); 318 return count == -1 ? 0 : (size_t) count; 319 } 320 321 size_t size_free_chunks_in_bytes(ChunkIndex index) const { 322 index_bounds_check(index); 323 324 size_t word_size = 0; 325 if (index == HumongousIndex) { 326 word_size = _humongous_dictionary.total_size(); 327 } else { 328 const size_t size_per_chunk_in_words = _free_chunks[index].size(); 329 word_size = size_per_chunk_in_words * num_free_chunks(index); 330 } 331 332 return word_size * BytesPerWord; 333 } 334 335 MetaspaceChunkFreeListSummary chunk_free_list_summary() const { 336 return MetaspaceChunkFreeListSummary(num_free_chunks(SpecializedIndex), 337 num_free_chunks(SmallIndex), 338 num_free_chunks(MediumIndex), 339 num_free_chunks(HumongousIndex), 340 size_free_chunks_in_bytes(SpecializedIndex), 341 size_free_chunks_in_bytes(SmallIndex), 342 size_free_chunks_in_bytes(MediumIndex), 343 size_free_chunks_in_bytes(HumongousIndex)); 344 } 345 346 // Debug support 347 void verify(); 348 void slow_verify() { 349 if (metaspace_slow_verify) { 350 verify(); 351 } 352 } 353 void locked_verify(); 354 void slow_locked_verify() { 355 if (metaspace_slow_verify) { 356 locked_verify(); 357 } 358 } 359 void verify_free_chunks_total(); 360 361 void locked_print_free_chunks(outputStream* st); 362 void locked_print_sum_free_chunks(outputStream* st); 363 364 void print_on(outputStream* st) const; 365 366 // Prints composition for both non-class and (if available) 367 // class chunk manager. 368 static void print_all_chunkmanagers(outputStream* out, size_t scale = 1); 369 }; 370 371 class SmallBlocks : public CHeapObj<mtClass> { 372 const static uint _small_block_max_size = sizeof(TreeChunk<Metablock, FreeList<Metablock> >)/HeapWordSize; 373 const static uint _small_block_min_size = sizeof(Metablock)/HeapWordSize; 374 375 private: 376 FreeList<Metablock> _small_lists[_small_block_max_size - _small_block_min_size]; 377 378 FreeList<Metablock>& list_at(size_t word_size) { 379 assert(word_size >= _small_block_min_size, "There are no metaspace objects less than %u words", _small_block_min_size); 380 return _small_lists[word_size - _small_block_min_size]; 381 } 382 383 public: 384 SmallBlocks() { 385 for (uint i = _small_block_min_size; i < _small_block_max_size; i++) { 386 uint k = i - _small_block_min_size; 387 _small_lists[k].set_size(i); 388 } 389 } 390 391 size_t total_size() const { 392 size_t result = 0; 393 for (uint i = _small_block_min_size; i < _small_block_max_size; i++) { 394 uint k = i - _small_block_min_size; 395 result = result + _small_lists[k].count() * _small_lists[k].size(); 396 } 397 return result; 398 } 399 400 static uint small_block_max_size() { return _small_block_max_size; } 401 static uint small_block_min_size() { return _small_block_min_size; } 402 403 MetaWord* get_block(size_t word_size) { 404 if (list_at(word_size).count() > 0) { 405 MetaWord* new_block = (MetaWord*) list_at(word_size).get_chunk_at_head(); 406 return new_block; 407 } else { 408 return NULL; 409 } 410 } 411 void return_block(Metablock* free_chunk, size_t word_size) { 412 list_at(word_size).return_chunk_at_head(free_chunk, false); 413 assert(list_at(word_size).count() > 0, "Should have a chunk"); 414 } 415 416 void print_on(outputStream* st) const { 417 st->print_cr("SmallBlocks:"); 418 for (uint i = _small_block_min_size; i < _small_block_max_size; i++) { 419 uint k = i - _small_block_min_size; 420 st->print_cr("small_lists size " SIZE_FORMAT " count " SIZE_FORMAT, _small_lists[k].size(), _small_lists[k].count()); 421 } 422 } 423 }; 424 425 // Used to manage the free list of Metablocks (a block corresponds 426 // to the allocation of a quantum of metadata). 427 class BlockFreelist : public CHeapObj<mtClass> { 428 BlockTreeDictionary* const _dictionary; 429 SmallBlocks* _small_blocks; 430 431 // Only allocate and split from freelist if the size of the allocation 432 // is at least 1/4th the size of the available block. 433 const static int WasteMultiplier = 4; 434 435 // Accessors 436 BlockTreeDictionary* dictionary() const { return _dictionary; } 437 SmallBlocks* small_blocks() { 438 if (_small_blocks == NULL) { 439 _small_blocks = new SmallBlocks(); 440 } 441 return _small_blocks; 442 } 443 444 public: 445 BlockFreelist(); 446 ~BlockFreelist(); 447 448 // Get and return a block to the free list 449 MetaWord* get_block(size_t word_size); 450 void return_block(MetaWord* p, size_t word_size); 451 452 size_t total_size() const { 453 size_t result = dictionary()->total_size(); 454 if (_small_blocks != NULL) { 455 result = result + _small_blocks->total_size(); 456 } 457 return result; 458 } 459 460 static size_t min_dictionary_size() { return TreeChunk<Metablock, FreeList<Metablock> >::min_size(); } 461 void print_on(outputStream* st) const; 462 }; 463 464 // Helper for Occupancy Bitmap. A type trait to give an all-bits-are-one-unsigned constant. 465 template <typename T> struct all_ones { static const T value; }; 466 template <> struct all_ones <uint64_t> { static const uint64_t value = 0xFFFFFFFFFFFFFFFFULL; }; 467 template <> struct all_ones <uint32_t> { static const uint32_t value = 0xFFFFFFFF; }; 468 469 // The OccupancyMap is a bitmap which, for a given VirtualSpaceNode, 470 // keeps information about 471 // - where a chunk starts 472 // - whether a chunk is in-use or free 473 // A bit in this bitmap represents one range of memory in the smallest 474 // chunk size (SpecializedChunk or ClassSpecializedChunk). 475 class OccupancyMap : public CHeapObj<mtInternal> { 476 477 // The address range this map covers. 478 const MetaWord* const _reference_address; 479 const size_t _word_size; 480 481 // The word size of a specialized chunk, aka the number of words one 482 // bit in this map represents. 483 const size_t _smallest_chunk_word_size; 484 485 // map data 486 // Data are organized in two bit layers: 487 // The first layer is the chunk-start-map. Here, a bit is set to mark 488 // the corresponding region as the head of a chunk. 489 // The second layer is the in-use-map. Here, a set bit indicates that 490 // the corresponding belongs to a chunk which is in use. 491 uint8_t* _map[2]; 492 493 enum { layer_chunk_start_map = 0, layer_in_use_map = 1 }; 494 495 // length, in bytes, of bitmap data 496 size_t _map_size; 497 498 // Returns true if bit at position pos at bit-layer layer is set. 499 bool get_bit_at_position(unsigned pos, unsigned layer) const { 500 assert(layer == 0 || layer == 1, "Invalid layer %d", layer); 501 const unsigned byteoffset = pos / 8; 502 assert(byteoffset < _map_size, 503 "invalid byte offset (%u), map size is " SIZE_FORMAT ".", byteoffset, _map_size); 504 const unsigned mask = 1 << (pos % 8); 505 return (_map[layer][byteoffset] & mask) > 0; 506 } 507 508 // Changes bit at position pos at bit-layer layer to value v. 509 void set_bit_at_position(unsigned pos, unsigned layer, bool v) { 510 assert(layer == 0 || layer == 1, "Invalid layer %d", layer); 511 const unsigned byteoffset = pos / 8; 512 assert(byteoffset < _map_size, 513 "invalid byte offset (%u), map size is " SIZE_FORMAT ".", byteoffset, _map_size); 514 const unsigned mask = 1 << (pos % 8); 515 if (v) { 516 _map[layer][byteoffset] |= mask; 517 } else { 518 _map[layer][byteoffset] &= ~mask; 519 } 520 } 521 522 // Optimized case of is_any_bit_set_in_region for 32/64bit aligned access: 523 // pos is 32/64 aligned and num_bits is 32/64. 524 // This is the typical case when coalescing to medium chunks, whose size is 525 // 32 or 64 times the specialized chunk size (depending on class or non class 526 // case), so they occupy 64 bits which should be 64bit aligned, because 527 // chunks are chunk-size aligned. 528 template <typename T> 529 bool is_any_bit_set_in_region_3264(unsigned pos, unsigned num_bits, unsigned layer) const { 530 assert(_map_size > 0, "not initialized"); 531 assert(layer == 0 || layer == 1, "Invalid layer %d.", layer); 532 assert(pos % (sizeof(T) * 8) == 0, "Bit position must be aligned (%u).", pos); 533 assert(num_bits == (sizeof(T) * 8), "Number of bits incorrect (%u).", num_bits); 534 const size_t byteoffset = pos / 8; 535 assert(byteoffset <= (_map_size - sizeof(T)), 536 "Invalid byte offset (" SIZE_FORMAT "), map size is " SIZE_FORMAT ".", byteoffset, _map_size); 537 const T w = *(T*)(_map[layer] + byteoffset); 538 return w > 0 ? true : false; 539 } 540 541 // Returns true if any bit in region [pos1, pos1 + num_bits) is set in bit-layer layer. 542 bool is_any_bit_set_in_region(unsigned pos, unsigned num_bits, unsigned layer) const { 543 if (pos % 32 == 0 && num_bits == 32) { 544 return is_any_bit_set_in_region_3264<uint32_t>(pos, num_bits, layer); 545 } else if (pos % 64 == 0 && num_bits == 64) { 546 return is_any_bit_set_in_region_3264<uint64_t>(pos, num_bits, layer); 547 } else { 548 for (unsigned n = 0; n < num_bits; n ++) { 549 if (get_bit_at_position(pos + n, layer)) { 550 return true; 551 } 552 } 553 } 554 return false; 555 } 556 557 // Returns true if any bit in region [p, p+word_size) is set in bit-layer layer. 558 bool is_any_bit_set_in_region(MetaWord* p, size_t word_size, unsigned layer) const { 559 assert(word_size % _smallest_chunk_word_size == 0, 560 "Region size " SIZE_FORMAT " not a multiple of smallest chunk size.", word_size); 561 const unsigned pos = get_bitpos_for_address(p); 562 const unsigned num_bits = (unsigned) (word_size / _smallest_chunk_word_size); 563 return is_any_bit_set_in_region(pos, num_bits, layer); 564 } 565 566 // Optimized case of set_bits_of_region for 32/64bit aligned access: 567 // pos is 32/64 aligned and num_bits is 32/64. 568 // This is the typical case when coalescing to medium chunks, whose size 569 // is 32 or 64 times the specialized chunk size (depending on class or non 570 // class case), so they occupy 64 bits which should be 64bit aligned, 571 // because chunks are chunk-size aligned. 572 template <typename T> 573 void set_bits_of_region_T(unsigned pos, unsigned num_bits, unsigned layer, bool v) { 574 assert(pos % (sizeof(T) * 8) == 0, "Bit position must be aligned to %u (%u).", 575 (unsigned)(sizeof(T) * 8), pos); 576 assert(num_bits == (sizeof(T) * 8), "Number of bits incorrect (%u), expected %u.", 577 num_bits, (unsigned)(sizeof(T) * 8)); 578 const size_t byteoffset = pos / 8; 579 assert(byteoffset <= (_map_size - sizeof(T)), 580 "invalid byte offset (" SIZE_FORMAT "), map size is " SIZE_FORMAT ".", byteoffset, _map_size); 581 T* const pw = (T*)(_map[layer] + byteoffset); 582 *pw = v ? all_ones<T>::value : (T) 0; 583 } 584 585 // Set all bits in a region starting at pos to a value. 586 void set_bits_of_region(unsigned pos, unsigned num_bits, unsigned layer, bool v) { 587 assert(_map_size > 0, "not initialized"); 588 assert(layer == 0 || layer == 1, "Invalid layer %d.", layer); 589 if (pos % 32 == 0 && num_bits == 32) { 590 set_bits_of_region_T<uint32_t>(pos, num_bits, layer, v); 591 } else if (pos % 64 == 0 && num_bits == 64) { 592 set_bits_of_region_T<uint64_t>(pos, num_bits, layer, v); 593 } else { 594 for (unsigned n = 0; n < num_bits; n ++) { 595 set_bit_at_position(pos + n, layer, v); 596 } 597 } 598 } 599 600 // Helper: sets all bits in a region [p, p+word_size). 601 void set_bits_of_region(MetaWord* p, size_t word_size, unsigned layer, bool v) { 602 assert(word_size % _smallest_chunk_word_size == 0, 603 "Region size " SIZE_FORMAT " not a multiple of smallest chunk size.", word_size); 604 const unsigned pos = get_bitpos_for_address(p); 605 const unsigned num_bits = (unsigned) (word_size / _smallest_chunk_word_size); 606 set_bits_of_region(pos, num_bits, layer, v); 607 } 608 609 // Helper: given an address, return the bit position representing that address. 610 unsigned get_bitpos_for_address(const MetaWord* p) const { 611 assert(_reference_address != NULL, "not initialized"); 612 assert(p >= _reference_address && p < _reference_address + _word_size, 613 "Address %p out of range for occupancy map [%p..%p).", 614 p, _reference_address, _reference_address + _word_size); 615 assert(is_aligned(p, _smallest_chunk_word_size * sizeof(MetaWord)), 616 "Address not aligned (%p).", p); 617 const ptrdiff_t d = (p - _reference_address) / _smallest_chunk_word_size; 618 assert(d >= 0 && (size_t)d < _map_size * 8, "Sanity."); 619 return (unsigned) d; 620 } 621 622 public: 623 624 OccupancyMap(const MetaWord* reference_address, size_t word_size, size_t smallest_chunk_word_size) : 625 _reference_address(reference_address), _word_size(word_size), 626 _smallest_chunk_word_size(smallest_chunk_word_size) { 627 assert(reference_address != NULL, "invalid reference address"); 628 assert(is_aligned(reference_address, smallest_chunk_word_size), 629 "Reference address not aligned to smallest chunk size."); 630 assert(is_aligned(word_size, smallest_chunk_word_size), 631 "Word_size shall be a multiple of the smallest chunk size."); 632 // Calculate bitmap size: one bit per smallest_chunk_word_size'd area. 633 size_t num_bits = word_size / smallest_chunk_word_size; 634 _map_size = (num_bits + 7) / 8; 635 assert(_map_size * 8 >= num_bits, "sanity"); 636 _map[0] = (uint8_t*) os::malloc(_map_size, mtInternal); 637 _map[1] = (uint8_t*) os::malloc(_map_size, mtInternal); 638 assert(_map[0] != NULL && _map[1] != NULL, "Occupancy Map: allocation failed."); 639 memset(_map[1], 0, _map_size); 640 memset(_map[0], 0, _map_size); 641 // Sanity test: the first respectively last possible chunk start address in 642 // the covered range shall map to the first and last bit in the bitmap. 643 assert(get_bitpos_for_address(reference_address) == 0, 644 "First chunk address in range must map to fist bit in bitmap."); 645 assert(get_bitpos_for_address(reference_address + word_size - smallest_chunk_word_size) == num_bits - 1, 646 "Last chunk address in range must map to last bit in bitmap."); 647 } 648 649 ~OccupancyMap() { 650 os::free(_map[0]); 651 os::free(_map[1]); 652 } 653 654 // Returns true if at address x a chunk is starting. 655 bool chunk_starts_at_address(MetaWord* p) const { 656 const unsigned pos = get_bitpos_for_address(p); 657 return get_bit_at_position(pos, layer_chunk_start_map); 658 } 659 660 void set_chunk_starts_at_address(MetaWord* p, bool v) { 661 const unsigned pos = get_bitpos_for_address(p); 662 set_bit_at_position(pos, layer_chunk_start_map, v); 663 } 664 665 // Removes all chunk-start-bits inside a region, typically as a 666 // result of a chunk merge. 667 void wipe_chunk_start_bits_in_region(MetaWord* p, size_t word_size) { 668 set_bits_of_region(p, word_size, layer_chunk_start_map, false); 669 } 670 671 // Returns true if there are life (in use) chunks in the region limited 672 // by [p, p+word_size). 673 bool is_region_in_use(MetaWord* p, size_t word_size) const { 674 return is_any_bit_set_in_region(p, word_size, layer_in_use_map); 675 } 676 677 // Marks the region starting at p with the size word_size as in use 678 // or free, depending on v. 679 void set_region_in_use(MetaWord* p, size_t word_size, bool v) { 680 set_bits_of_region(p, word_size, layer_in_use_map, v); 681 } 682 683 #ifdef ASSERT 684 // Verify occupancy map for the address range [from, to). 685 // We need to tell it the address range, because the memory the 686 // occupancy map is covering may not be fully comitted yet. 687 void verify(MetaWord* from, MetaWord* to) { 688 Metachunk* chunk = NULL; 689 int nth_bit_for_chunk = 0; 690 MetaWord* chunk_end = NULL; 691 for (MetaWord* p = from; p < to; p += _smallest_chunk_word_size) { 692 const unsigned pos = get_bitpos_for_address(p); 693 // Check the chunk-starts-info: 694 if (get_bit_at_position(pos, layer_chunk_start_map)) { 695 // Chunk start marked in bitmap. 696 chunk = (Metachunk*) p; 697 if (chunk_end != NULL) { 698 assert(chunk_end == p, "Unexpected chunk start found at %p (expected " 699 "the next chunk to start at %p).", p, chunk_end); 700 } 701 assert(chunk->is_valid_sentinel(), "Invalid chunk at address %p.", p); 702 if (chunk->get_chunk_type() != HumongousIndex) { 703 guarantee(is_aligned(p, chunk->word_size()), "Chunk %p not aligned.", p); 704 } 705 chunk_end = p + chunk->word_size(); 706 nth_bit_for_chunk = 0; 707 assert(chunk_end <= to, "Chunk end overlaps test address range."); 708 } else { 709 // No chunk start marked in bitmap. 710 assert(chunk != NULL, "Chunk should start at start of address range."); 711 assert(p < chunk_end, "Did not find expected chunk start at %p.", p); 712 nth_bit_for_chunk ++; 713 } 714 // Check the in-use-info: 715 const bool in_use_bit = get_bit_at_position(pos, layer_in_use_map); 716 if (in_use_bit) { 717 assert(!chunk->is_tagged_free(), "Chunk %p: marked in-use in map but is free (bit %u).", 718 chunk, nth_bit_for_chunk); 719 } else { 720 assert(chunk->is_tagged_free(), "Chunk %p: marked free in map but is in use (bit %u).", 721 chunk, nth_bit_for_chunk); 722 } 723 } 724 } 725 726 // Verify that a given chunk is correctly accounted for in the bitmap. 727 void verify_for_chunk(Metachunk* chunk) { 728 assert(chunk_starts_at_address((MetaWord*) chunk), 729 "No chunk start marked in map for chunk %p.", chunk); 730 // For chunks larger than the minimal chunk size, no other chunk 731 // must start in its area. 732 if (chunk->word_size() > _smallest_chunk_word_size) { 733 assert(!is_any_bit_set_in_region(((MetaWord*) chunk) + _smallest_chunk_word_size, 734 chunk->word_size() - _smallest_chunk_word_size, layer_chunk_start_map), 735 "No chunk must start within another chunk."); 736 } 737 if (!chunk->is_tagged_free()) { 738 assert(is_region_in_use((MetaWord*)chunk, chunk->word_size()), 739 "Chunk %p is in use but marked as free in map (%d %d).", 740 chunk, chunk->get_chunk_type(), chunk->get_origin()); 741 } else { 742 assert(!is_region_in_use((MetaWord*)chunk, chunk->word_size()), 743 "Chunk %p is free but marked as in-use in map (%d %d).", 744 chunk, chunk->get_chunk_type(), chunk->get_origin()); 745 } 746 } 747 748 #endif // ASSERT 749 750 }; 751 752 // A VirtualSpaceList node. 753 class VirtualSpaceNode : public CHeapObj<mtClass> { 754 friend class VirtualSpaceList; 755 756 // Link to next VirtualSpaceNode 757 VirtualSpaceNode* _next; 758 759 // Whether this node is contained in class or metaspace. 760 const bool _is_class; 761 762 // total in the VirtualSpace 763 MemRegion _reserved; 764 ReservedSpace _rs; 765 VirtualSpace _virtual_space; 766 MetaWord* _top; 767 // count of chunks contained in this VirtualSpace 768 uintx _container_count; 769 770 OccupancyMap* _occupancy_map; 771 772 // Convenience functions to access the _virtual_space 773 char* low() const { return virtual_space()->low(); } 774 char* high() const { return virtual_space()->high(); } 775 776 // The first Metachunk will be allocated at the bottom of the 777 // VirtualSpace 778 Metachunk* first_chunk() { return (Metachunk*) bottom(); } 779 780 // Committed but unused space in the virtual space 781 size_t free_words_in_vs() const; 782 783 // True if this node belongs to class metaspace. 784 bool is_class() const { return _is_class; } 785 786 // Helper function for take_from_committed: allocate padding chunks 787 // until top is at the given address. 788 void allocate_padding_chunks_until_top_is_at(MetaWord* target_top); 789 790 public: 791 792 VirtualSpaceNode(bool is_class, size_t byte_size); 793 VirtualSpaceNode(bool is_class, ReservedSpace rs) : 794 _is_class(is_class), _top(NULL), _next(NULL), _rs(rs), _container_count(0), _occupancy_map(NULL) {} 795 ~VirtualSpaceNode(); 796 797 // Convenience functions for logical bottom and end 798 MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); } 799 MetaWord* end() const { return (MetaWord*) _virtual_space.high(); } 800 801 const OccupancyMap* occupancy_map() const { return _occupancy_map; } 802 OccupancyMap* occupancy_map() { return _occupancy_map; } 803 804 bool contains(const void* ptr) { return ptr >= low() && ptr < high(); } 805 806 size_t reserved_words() const { return _virtual_space.reserved_size() / BytesPerWord; } 807 size_t committed_words() const { return _virtual_space.actual_committed_size() / BytesPerWord; } 808 809 bool is_pre_committed() const { return _virtual_space.special(); } 810 811 // address of next available space in _virtual_space; 812 // Accessors 813 VirtualSpaceNode* next() { return _next; } 814 void set_next(VirtualSpaceNode* v) { _next = v; } 815 816 void set_reserved(MemRegion const v) { _reserved = v; } 817 void set_top(MetaWord* v) { _top = v; } 818 819 // Accessors 820 MemRegion* reserved() { return &_reserved; } 821 VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; } 822 823 // Returns true if "word_size" is available in the VirtualSpace 824 bool is_available(size_t word_size) { return word_size <= pointer_delta(end(), _top, sizeof(MetaWord)); } 825 826 MetaWord* top() const { return _top; } 827 void inc_top(size_t word_size) { _top += word_size; } 828 829 uintx container_count() { return _container_count; } 830 void inc_container_count(); 831 void dec_container_count(); 832 #ifdef ASSERT 833 uintx container_count_slow(); 834 void verify_container_count(); 835 #endif 836 837 // used and capacity in this single entry in the list 838 size_t used_words_in_vs() const; 839 size_t capacity_words_in_vs() const; 840 841 bool initialize(); 842 843 // get space from the virtual space 844 Metachunk* take_from_committed(size_t chunk_word_size); 845 846 // Allocate a chunk from the virtual space and return it. 847 Metachunk* get_chunk_vs(size_t chunk_word_size); 848 849 // Expands/shrinks the committed space in a virtual space. Delegates 850 // to Virtualspace 851 bool expand_by(size_t min_words, size_t preferred_words); 852 853 // In preparation for deleting this node, remove all the chunks 854 // in the node from any freelist. 855 void purge(ChunkManager* chunk_manager); 856 857 // If an allocation doesn't fit in the current node a new node is created. 858 // Allocate chunks out of the remaining committed space in this node 859 // to avoid wasting that memory. 860 // This always adds up because all the chunk sizes are multiples of 861 // the smallest chunk size. 862 void retire(ChunkManager* chunk_manager); 863 864 865 void print_on(outputStream* st) const; 866 void print_map(outputStream* st, bool is_class) const; 867 868 // Debug support 869 DEBUG_ONLY(void mangle();) 870 // Verify counters, all chunks in this list node and the occupancy map. 871 DEBUG_ONLY(void verify();) 872 // Verify that all free chunks in this node are ideally merged 873 // (there not should be multiple small chunks where a large chunk could exist.) 874 DEBUG_ONLY(void verify_free_chunks_are_ideally_merged();) 875 876 }; 877 878 #define assert_is_aligned(value, alignment) \ 879 assert(is_aligned((value), (alignment)), \ 880 SIZE_FORMAT_HEX " is not aligned to " \ 881 SIZE_FORMAT, (size_t)(uintptr_t)value, (alignment)) 882 883 // Decide if large pages should be committed when the memory is reserved. 884 static bool should_commit_large_pages_when_reserving(size_t bytes) { 885 if (UseLargePages && UseLargePagesInMetaspace && !os::can_commit_large_page_memory()) { 886 size_t words = bytes / BytesPerWord; 887 bool is_class = false; // We never reserve large pages for the class space. 888 if (MetaspaceGC::can_expand(words, is_class) && 889 MetaspaceGC::allowed_expansion() >= words) { 890 return true; 891 } 892 } 893 894 return false; 895 } 896 897 // byte_size is the size of the associated virtualspace. 898 VirtualSpaceNode::VirtualSpaceNode(bool is_class, size_t bytes) : 899 _is_class(is_class), _top(NULL), _next(NULL), _rs(), _container_count(0), _occupancy_map(NULL) { 900 assert_is_aligned(bytes, Metaspace::reserve_alignment()); 901 bool large_pages = should_commit_large_pages_when_reserving(bytes); 902 _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages); 903 904 if (_rs.is_reserved()) { 905 assert(_rs.base() != NULL, "Catch if we get a NULL address"); 906 assert(_rs.size() != 0, "Catch if we get a 0 size"); 907 assert_is_aligned(_rs.base(), Metaspace::reserve_alignment()); 908 assert_is_aligned(_rs.size(), Metaspace::reserve_alignment()); 909 910 MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass); 911 } 912 } 913 914 void VirtualSpaceNode::purge(ChunkManager* chunk_manager) { 915 DEBUG_ONLY(this->verify();) 916 Metachunk* chunk = first_chunk(); 917 Metachunk* invalid_chunk = (Metachunk*) top(); 918 while (chunk < invalid_chunk ) { 919 assert(chunk->is_tagged_free(), "Should be tagged free"); 920 MetaWord* next = ((MetaWord*)chunk) + chunk->word_size(); 921 chunk_manager->remove_chunk(chunk); 922 chunk->remove_sentinel(); 923 assert(chunk->next() == NULL && 924 chunk->prev() == NULL, 925 "Was not removed from its list"); 926 chunk = (Metachunk*) next; 927 } 928 } 929 930 void VirtualSpaceNode::print_map(outputStream* st, bool is_class) const { 931 932 if (bottom() == top()) { 933 return; 934 } 935 936 const size_t spec_chunk_size = is_class ? ClassSpecializedChunk : SpecializedChunk; 937 const size_t small_chunk_size = is_class ? ClassSmallChunk : SmallChunk; 938 const size_t med_chunk_size = is_class ? ClassMediumChunk : MediumChunk; 939 940 int line_len = 100; 941 const size_t section_len = align_up(spec_chunk_size * line_len, med_chunk_size); 942 line_len = (int)(section_len / spec_chunk_size); 943 944 static const int NUM_LINES = 4; 945 946 char* lines[NUM_LINES]; 947 for (int i = 0; i < NUM_LINES; i ++) { 948 lines[i] = (char*)os::malloc(line_len, mtInternal); 949 } 950 int pos = 0; 951 const MetaWord* p = bottom(); 952 const Metachunk* chunk = (const Metachunk*)p; 953 const MetaWord* chunk_end = p + chunk->word_size(); 954 while (p < top()) { 955 if (pos == line_len) { 956 pos = 0; 957 for (int i = 0; i < NUM_LINES; i ++) { 958 st->fill_to(22); 959 st->print_raw(lines[i], line_len); 960 st->cr(); 961 } 962 } 963 if (pos == 0) { 964 st->print(PTR_FORMAT ":", p2i(p)); 965 } 966 if (p == chunk_end) { 967 chunk = (Metachunk*)p; 968 chunk_end = p + chunk->word_size(); 969 } 970 // line 1: chunk starting points (a dot if that area is a chunk start). 971 lines[0][pos] = p == (const MetaWord*)chunk ? '.' : ' '; 972 973 // Line 2: chunk type (x=spec, s=small, m=medium, h=humongous), uppercase if 974 // chunk is in use. 975 const bool chunk_is_free = ((Metachunk*)chunk)->is_tagged_free(); 976 if (chunk->word_size() == spec_chunk_size) { 977 lines[1][pos] = chunk_is_free ? 'x' : 'X'; 978 } else if (chunk->word_size() == small_chunk_size) { 979 lines[1][pos] = chunk_is_free ? 's' : 'S'; 980 } else if (chunk->word_size() == med_chunk_size) { 981 lines[1][pos] = chunk_is_free ? 'm' : 'M'; 982 } else if (chunk->word_size() > med_chunk_size) { 983 lines[1][pos] = chunk_is_free ? 'h' : 'H'; 984 } else { 985 ShouldNotReachHere(); 986 } 987 988 // Line 3: chunk origin 989 const ChunkOrigin origin = chunk->get_origin(); 990 lines[2][pos] = origin == origin_normal ? ' ' : '0' + (int) origin; 991 992 // Line 4: Virgin chunk? Virgin chunks are chunks created as a byproduct of padding or splitting, 993 // but were never used. 994 lines[3][pos] = chunk->get_use_count() > 0 ? ' ' : 'v'; 995 996 p += spec_chunk_size; 997 pos ++; 998 } 999 if (pos > 0) { 1000 for (int i = 0; i < NUM_LINES; i ++) { 1001 st->fill_to(22); 1002 st->print_raw(lines[i], line_len); 1003 st->cr(); 1004 } 1005 } 1006 for (int i = 0; i < NUM_LINES; i ++) { 1007 os::free(lines[i]); 1008 } 1009 } 1010 1011 1012 #ifdef ASSERT 1013 uintx VirtualSpaceNode::container_count_slow() { 1014 uintx count = 0; 1015 Metachunk* chunk = first_chunk(); 1016 Metachunk* invalid_chunk = (Metachunk*) top(); 1017 while (chunk < invalid_chunk ) { 1018 MetaWord* next = ((MetaWord*)chunk) + chunk->word_size(); 1019 do_verify_chunk(chunk); 1020 // Don't count the chunks on the free lists. Those are 1021 // still part of the VirtualSpaceNode but not currently 1022 // counted. 1023 if (!chunk->is_tagged_free()) { 1024 count++; 1025 } 1026 chunk = (Metachunk*) next; 1027 } 1028 return count; 1029 } 1030 #endif 1031 1032 #ifdef ASSERT 1033 // Verify counters, all chunks in this list node and the occupancy map. 1034 void VirtualSpaceNode::verify() { 1035 uintx num_in_use_chunks = 0; 1036 Metachunk* chunk = first_chunk(); 1037 Metachunk* invalid_chunk = (Metachunk*) top(); 1038 1039 // Iterate the chunks in this node and verify each chunk. 1040 while (chunk < invalid_chunk ) { 1041 DEBUG_ONLY(do_verify_chunk(chunk);) 1042 if (!chunk->is_tagged_free()) { 1043 num_in_use_chunks ++; 1044 } 1045 MetaWord* next = ((MetaWord*)chunk) + chunk->word_size(); 1046 chunk = (Metachunk*) next; 1047 } 1048 assert(_container_count == num_in_use_chunks, "Container count mismatch (real: " UINTX_FORMAT 1049 ", counter: " UINTX_FORMAT ".", num_in_use_chunks, _container_count); 1050 // Also verify the occupancy map. 1051 occupancy_map()->verify(this->bottom(), this->top()); 1052 } 1053 #endif // ASSERT 1054 1055 #ifdef ASSERT 1056 // Verify that all free chunks in this node are ideally merged 1057 // (there not should be multiple small chunks where a large chunk could exist.) 1058 void VirtualSpaceNode::verify_free_chunks_are_ideally_merged() { 1059 Metachunk* chunk = first_chunk(); 1060 Metachunk* invalid_chunk = (Metachunk*) top(); 1061 // Shorthands. 1062 const size_t size_med = (is_class() ? ClassMediumChunk : MediumChunk) * BytesPerWord; 1063 const size_t size_small = (is_class() ? ClassSmallChunk : SmallChunk) * BytesPerWord; 1064 int num_free_chunks_since_last_med_boundary = -1; 1065 int num_free_chunks_since_last_small_boundary = -1; 1066 while (chunk < invalid_chunk ) { 1067 // Test for missed chunk merge opportunities: count number of free chunks since last chunk boundary. 1068 // Reset the counter when encountering a non-free chunk. 1069 if (chunk->get_chunk_type() != HumongousIndex) { 1070 if (chunk->is_tagged_free()) { 1071 // Count successive free, non-humongous chunks. 1072 if (is_aligned(chunk, size_small)) { 1073 assert(num_free_chunks_since_last_small_boundary <= 1, 1074 "Missed chunk merge opportunity at " PTR_FORMAT " for chunk size " SIZE_FORMAT_HEX ".", p2i(chunk) - size_small, size_small); 1075 num_free_chunks_since_last_small_boundary = 0; 1076 } else if (num_free_chunks_since_last_small_boundary != -1) { 1077 num_free_chunks_since_last_small_boundary ++; 1078 } 1079 if (is_aligned(chunk, size_med)) { 1080 assert(num_free_chunks_since_last_med_boundary <= 1, 1081 "Missed chunk merge opportunity at " PTR_FORMAT " for chunk size " SIZE_FORMAT_HEX ".", p2i(chunk) - size_med, size_med); 1082 num_free_chunks_since_last_med_boundary = 0; 1083 } else if (num_free_chunks_since_last_med_boundary != -1) { 1084 num_free_chunks_since_last_med_boundary ++; 1085 } 1086 } else { 1087 // Encountering a non-free chunk, reset counters. 1088 num_free_chunks_since_last_med_boundary = -1; 1089 num_free_chunks_since_last_small_boundary = -1; 1090 } 1091 } else { 1092 // One cannot merge areas with a humongous chunk in the middle. Reset counters. 1093 num_free_chunks_since_last_med_boundary = -1; 1094 num_free_chunks_since_last_small_boundary = -1; 1095 } 1096 1097 MetaWord* next = ((MetaWord*)chunk) + chunk->word_size(); 1098 chunk = (Metachunk*) next; 1099 } 1100 } 1101 #endif // ASSERT 1102 1103 // List of VirtualSpaces for metadata allocation. 1104 class VirtualSpaceList : public CHeapObj<mtClass> { 1105 friend class VirtualSpaceNode; 1106 1107 enum VirtualSpaceSizes { 1108 VirtualSpaceSize = 256 * K 1109 }; 1110 1111 // Head of the list 1112 VirtualSpaceNode* _virtual_space_list; 1113 // virtual space currently being used for allocations 1114 VirtualSpaceNode* _current_virtual_space; 1115 1116 // Is this VirtualSpaceList used for the compressed class space 1117 bool _is_class; 1118 1119 // Sum of reserved and committed memory in the virtual spaces 1120 size_t _reserved_words; 1121 size_t _committed_words; 1122 1123 // Number of virtual spaces 1124 size_t _virtual_space_count; 1125 1126 ~VirtualSpaceList(); 1127 1128 VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; } 1129 1130 void set_virtual_space_list(VirtualSpaceNode* v) { 1131 _virtual_space_list = v; 1132 } 1133 void set_current_virtual_space(VirtualSpaceNode* v) { 1134 _current_virtual_space = v; 1135 } 1136 1137 void link_vs(VirtualSpaceNode* new_entry); 1138 1139 // Get another virtual space and add it to the list. This 1140 // is typically prompted by a failed attempt to allocate a chunk 1141 // and is typically followed by the allocation of a chunk. 1142 bool create_new_virtual_space(size_t vs_word_size); 1143 1144 // Chunk up the unused committed space in the current 1145 // virtual space and add the chunks to the free list. 1146 void retire_current_virtual_space(); 1147 1148 public: 1149 VirtualSpaceList(size_t word_size); 1150 VirtualSpaceList(ReservedSpace rs); 1151 1152 size_t free_bytes(); 1153 1154 Metachunk* get_new_chunk(size_t chunk_word_size, 1155 size_t suggested_commit_granularity); 1156 1157 bool expand_node_by(VirtualSpaceNode* node, 1158 size_t min_words, 1159 size_t preferred_words); 1160 1161 bool expand_by(size_t min_words, 1162 size_t preferred_words); 1163 1164 VirtualSpaceNode* current_virtual_space() { 1165 return _current_virtual_space; 1166 } 1167 1168 bool is_class() const { return _is_class; } 1169 1170 bool initialization_succeeded() { return _virtual_space_list != NULL; } 1171 1172 size_t reserved_words() { return _reserved_words; } 1173 size_t reserved_bytes() { return reserved_words() * BytesPerWord; } 1174 size_t committed_words() { return _committed_words; } 1175 size_t committed_bytes() { return committed_words() * BytesPerWord; } 1176 1177 void inc_reserved_words(size_t v); 1178 void dec_reserved_words(size_t v); 1179 void inc_committed_words(size_t v); 1180 void dec_committed_words(size_t v); 1181 void inc_virtual_space_count(); 1182 void dec_virtual_space_count(); 1183 1184 bool contains(const void* ptr); 1185 1186 // Unlink empty VirtualSpaceNodes and free it. 1187 void purge(ChunkManager* chunk_manager); 1188 1189 void print_on(outputStream* st) const; 1190 void print_map(outputStream* st) const; 1191 1192 class VirtualSpaceListIterator : public StackObj { 1193 VirtualSpaceNode* _virtual_spaces; 1194 public: 1195 VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) : 1196 _virtual_spaces(virtual_spaces) {} 1197 1198 bool repeat() { 1199 return _virtual_spaces != NULL; 1200 } 1201 1202 VirtualSpaceNode* get_next() { 1203 VirtualSpaceNode* result = _virtual_spaces; 1204 if (_virtual_spaces != NULL) { 1205 _virtual_spaces = _virtual_spaces->next(); 1206 } 1207 return result; 1208 } 1209 }; 1210 }; 1211 1212 class Metadebug : AllStatic { 1213 // Debugging support for Metaspaces 1214 static int _allocation_fail_alot_count; 1215 1216 public: 1217 1218 static void init_allocation_fail_alot_count(); 1219 #ifdef ASSERT 1220 static bool test_metadata_failure(); 1221 #endif 1222 }; 1223 1224 int Metadebug::_allocation_fail_alot_count = 0; 1225 1226 // SpaceManager - used by Metaspace to handle allocations 1227 class SpaceManager : public CHeapObj<mtClass> { 1228 friend class Metaspace; 1229 friend class Metadebug; 1230 1231 private: 1232 1233 // protects allocations 1234 Mutex* const _lock; 1235 1236 // Type of metadata allocated. 1237 const Metaspace::MetadataType _mdtype; 1238 1239 // Type of metaspace 1240 const Metaspace::MetaspaceType _space_type; 1241 1242 // List of chunks in use by this SpaceManager. Allocations 1243 // are done from the current chunk. The list is used for deallocating 1244 // chunks when the SpaceManager is freed. 1245 Metachunk* _chunks_in_use[NumberOfInUseLists]; 1246 Metachunk* _current_chunk; 1247 1248 // Maximum number of small chunks to allocate to a SpaceManager 1249 static uint const _small_chunk_limit; 1250 1251 // Maximum number of specialize chunks to allocate for anonymous 1252 // metadata space to a SpaceManager 1253 static uint const _anon_metadata_specialize_chunk_limit; 1254 1255 // Sum of all space in allocated chunks 1256 size_t _allocated_blocks_words; 1257 1258 // Sum of all allocated chunks 1259 size_t _allocated_chunks_words; 1260 size_t _allocated_chunks_count; 1261 1262 // Free lists of blocks are per SpaceManager since they 1263 // are assumed to be in chunks in use by the SpaceManager 1264 // and all chunks in use by a SpaceManager are freed when 1265 // the class loader using the SpaceManager is collected. 1266 BlockFreelist* _block_freelists; 1267 1268 // protects virtualspace and chunk expansions 1269 static const char* _expand_lock_name; 1270 static const int _expand_lock_rank; 1271 static Mutex* const _expand_lock; 1272 1273 private: 1274 // Accessors 1275 Metachunk* chunks_in_use(ChunkIndex index) const { return _chunks_in_use[index]; } 1276 void set_chunks_in_use(ChunkIndex index, Metachunk* v) { 1277 _chunks_in_use[index] = v; 1278 } 1279 1280 BlockFreelist* block_freelists() const { return _block_freelists; } 1281 1282 Metaspace::MetadataType mdtype() { return _mdtype; } 1283 1284 VirtualSpaceList* vs_list() const { return Metaspace::get_space_list(_mdtype); } 1285 ChunkManager* chunk_manager() const { return Metaspace::get_chunk_manager(_mdtype); } 1286 1287 Metachunk* current_chunk() const { return _current_chunk; } 1288 void set_current_chunk(Metachunk* v) { 1289 _current_chunk = v; 1290 } 1291 1292 Metachunk* find_current_chunk(size_t word_size); 1293 1294 // Add chunk to the list of chunks in use 1295 void add_chunk(Metachunk* v, bool make_current); 1296 void retire_current_chunk(); 1297 1298 Mutex* lock() const { return _lock; } 1299 1300 protected: 1301 void initialize(); 1302 1303 public: 1304 SpaceManager(Metaspace::MetadataType mdtype, 1305 Metaspace::MetaspaceType space_type, 1306 Mutex* lock); 1307 ~SpaceManager(); 1308 1309 enum ChunkMultiples { 1310 MediumChunkMultiple = 4 1311 }; 1312 1313 static size_t specialized_chunk_size(bool is_class) { return is_class ? ClassSpecializedChunk : SpecializedChunk; } 1314 static size_t small_chunk_size(bool is_class) { return is_class ? ClassSmallChunk : SmallChunk; } 1315 static size_t medium_chunk_size(bool is_class) { return is_class ? ClassMediumChunk : MediumChunk; } 1316 1317 static size_t smallest_chunk_size(bool is_class) { return specialized_chunk_size(is_class); } 1318 1319 // Accessors 1320 bool is_class() const { return _mdtype == Metaspace::ClassType; } 1321 1322 size_t specialized_chunk_size() const { return specialized_chunk_size(is_class()); } 1323 size_t small_chunk_size() const { return small_chunk_size(is_class()); } 1324 size_t medium_chunk_size() const { return medium_chunk_size(is_class()); } 1325 1326 size_t smallest_chunk_size() const { return smallest_chunk_size(is_class()); } 1327 1328 size_t medium_chunk_bunch() const { return medium_chunk_size() * MediumChunkMultiple; } 1329 1330 size_t allocated_blocks_words() const { return _allocated_blocks_words; } 1331 size_t allocated_blocks_bytes() const { return _allocated_blocks_words * BytesPerWord; } 1332 size_t allocated_chunks_words() const { return _allocated_chunks_words; } 1333 size_t allocated_chunks_bytes() const { return _allocated_chunks_words * BytesPerWord; } 1334 size_t allocated_chunks_count() const { return _allocated_chunks_count; } 1335 1336 bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); } 1337 1338 static Mutex* expand_lock() { return _expand_lock; } 1339 1340 // Increment the per Metaspace and global running sums for Metachunks 1341 // by the given size. This is used when a Metachunk to added to 1342 // the in-use list. 1343 void inc_size_metrics(size_t words); 1344 // Increment the per Metaspace and global running sums Metablocks by the given 1345 // size. This is used when a Metablock is allocated. 1346 void inc_used_metrics(size_t words); 1347 // Delete the portion of the running sums for this SpaceManager. That is, 1348 // the globals running sums for the Metachunks and Metablocks are 1349 // decremented for all the Metachunks in-use by this SpaceManager. 1350 void dec_total_from_size_metrics(); 1351 1352 // Adjust the initial chunk size to match one of the fixed chunk list sizes, 1353 // or return the unadjusted size if the requested size is humongous. 1354 static size_t adjust_initial_chunk_size(size_t requested, bool is_class_space); 1355 size_t adjust_initial_chunk_size(size_t requested) const; 1356 1357 // Get the initial chunks size for this metaspace type. 1358 size_t get_initial_chunk_size(Metaspace::MetaspaceType type) const; 1359 1360 size_t sum_capacity_in_chunks_in_use() const; 1361 size_t sum_used_in_chunks_in_use() const; 1362 size_t sum_free_in_chunks_in_use() const; 1363 size_t sum_waste_in_chunks_in_use() const; 1364 size_t sum_waste_in_chunks_in_use(ChunkIndex index ) const; 1365 1366 size_t sum_count_in_chunks_in_use(); 1367 size_t sum_count_in_chunks_in_use(ChunkIndex i); 1368 1369 Metachunk* get_new_chunk(size_t chunk_word_size); 1370 1371 // Block allocation and deallocation. 1372 // Allocates a block from the current chunk 1373 MetaWord* allocate(size_t word_size); 1374 1375 // Helper for allocations 1376 MetaWord* allocate_work(size_t word_size); 1377 1378 // Returns a block to the per manager freelist 1379 void deallocate(MetaWord* p, size_t word_size); 1380 1381 // Based on the allocation size and a minimum chunk size, 1382 // returned chunk size (for expanding space for chunk allocation). 1383 size_t calc_chunk_size(size_t allocation_word_size); 1384 1385 // Called when an allocation from the current chunk fails. 1386 // Gets a new chunk (may require getting a new virtual space), 1387 // and allocates from that chunk. 1388 MetaWord* grow_and_allocate(size_t word_size); 1389 1390 // Notify memory usage to MemoryService. 1391 void track_metaspace_memory_usage(); 1392 1393 // debugging support. 1394 1395 void dump(outputStream* const out) const; 1396 void print_on(outputStream* st) const; 1397 void locked_print_chunks_in_use_on(outputStream* st) const; 1398 1399 void verify(); 1400 void verify_chunk_size(Metachunk* chunk); 1401 #ifdef ASSERT 1402 void verify_allocated_blocks_words(); 1403 #endif 1404 1405 // This adjusts the size given to be greater than the minimum allocation size in 1406 // words for data in metaspace. Esentially the minimum size is currently 3 words. 1407 size_t get_allocation_word_size(size_t word_size) { 1408 size_t byte_size = word_size * BytesPerWord; 1409 1410 size_t raw_bytes_size = MAX2(byte_size, sizeof(Metablock)); 1411 raw_bytes_size = align_up(raw_bytes_size, Metachunk::object_alignment()); 1412 1413 size_t raw_word_size = raw_bytes_size / BytesPerWord; 1414 assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem"); 1415 1416 return raw_word_size; 1417 } 1418 }; 1419 1420 uint const SpaceManager::_small_chunk_limit = 4; 1421 uint const SpaceManager::_anon_metadata_specialize_chunk_limit = 4; 1422 1423 const char* SpaceManager::_expand_lock_name = 1424 "SpaceManager chunk allocation lock"; 1425 const int SpaceManager::_expand_lock_rank = Monitor::leaf - 1; 1426 Mutex* const SpaceManager::_expand_lock = 1427 new Mutex(SpaceManager::_expand_lock_rank, 1428 SpaceManager::_expand_lock_name, 1429 Mutex::_allow_vm_block_flag, 1430 Monitor::_safepoint_check_never); 1431 1432 void VirtualSpaceNode::inc_container_count() { 1433 assert_lock_strong(SpaceManager::expand_lock()); 1434 _container_count++; 1435 } 1436 1437 void VirtualSpaceNode::dec_container_count() { 1438 assert_lock_strong(SpaceManager::expand_lock()); 1439 _container_count--; 1440 } 1441 1442 #ifdef ASSERT 1443 void VirtualSpaceNode::verify_container_count() { 1444 assert(_container_count == container_count_slow(), 1445 "Inconsistency in container_count _container_count " UINTX_FORMAT 1446 " container_count_slow() " UINTX_FORMAT, _container_count, container_count_slow()); 1447 } 1448 #endif 1449 1450 // BlockFreelist methods 1451 1452 BlockFreelist::BlockFreelist() : _dictionary(new BlockTreeDictionary()), _small_blocks(NULL) {} 1453 1454 BlockFreelist::~BlockFreelist() { 1455 delete _dictionary; 1456 if (_small_blocks != NULL) { 1457 delete _small_blocks; 1458 } 1459 } 1460 1461 void BlockFreelist::return_block(MetaWord* p, size_t word_size) { 1462 assert(word_size >= SmallBlocks::small_block_min_size(), "never return dark matter"); 1463 1464 Metablock* free_chunk = ::new (p) Metablock(word_size); 1465 if (word_size < SmallBlocks::small_block_max_size()) { 1466 small_blocks()->return_block(free_chunk, word_size); 1467 } else { 1468 dictionary()->return_chunk(free_chunk); 1469 } 1470 log_trace(gc, metaspace, freelist, blocks)("returning block at " INTPTR_FORMAT " size = " 1471 SIZE_FORMAT, p2i(free_chunk), word_size); 1472 } 1473 1474 MetaWord* BlockFreelist::get_block(size_t word_size) { 1475 assert(word_size >= SmallBlocks::small_block_min_size(), "never get dark matter"); 1476 1477 // Try small_blocks first. 1478 if (word_size < SmallBlocks::small_block_max_size()) { 1479 // Don't create small_blocks() until needed. small_blocks() allocates the small block list for 1480 // this space manager. 1481 MetaWord* new_block = (MetaWord*) small_blocks()->get_block(word_size); 1482 if (new_block != NULL) { 1483 log_trace(gc, metaspace, freelist, blocks)("getting block at " INTPTR_FORMAT " size = " SIZE_FORMAT, 1484 p2i(new_block), word_size); 1485 return new_block; 1486 } 1487 } 1488 1489 if (word_size < BlockFreelist::min_dictionary_size()) { 1490 // If allocation in small blocks fails, this is Dark Matter. Too small for dictionary. 1491 return NULL; 1492 } 1493 1494 Metablock* free_block = dictionary()->get_chunk(word_size); 1495 if (free_block == NULL) { 1496 return NULL; 1497 } 1498 1499 const size_t block_size = free_block->size(); 1500 if (block_size > WasteMultiplier * word_size) { 1501 return_block((MetaWord*)free_block, block_size); 1502 return NULL; 1503 } 1504 1505 MetaWord* new_block = (MetaWord*)free_block; 1506 assert(block_size >= word_size, "Incorrect size of block from freelist"); 1507 const size_t unused = block_size - word_size; 1508 if (unused >= SmallBlocks::small_block_min_size()) { 1509 return_block(new_block + word_size, unused); 1510 } 1511 1512 log_trace(gc, metaspace, freelist, blocks)("getting block at " INTPTR_FORMAT " size = " SIZE_FORMAT, 1513 p2i(new_block), word_size); 1514 return new_block; 1515 } 1516 1517 void BlockFreelist::print_on(outputStream* st) const { 1518 dictionary()->print_free_lists(st); 1519 if (_small_blocks != NULL) { 1520 _small_blocks->print_on(st); 1521 } 1522 } 1523 1524 // VirtualSpaceNode methods 1525 1526 VirtualSpaceNode::~VirtualSpaceNode() { 1527 _rs.release(); 1528 if (_occupancy_map != NULL) { 1529 delete _occupancy_map; 1530 } 1531 #ifdef ASSERT 1532 size_t word_size = sizeof(*this) / BytesPerWord; 1533 Copy::fill_to_words((HeapWord*) this, word_size, 0xf1f1f1f1); 1534 #endif 1535 } 1536 1537 size_t VirtualSpaceNode::used_words_in_vs() const { 1538 return pointer_delta(top(), bottom(), sizeof(MetaWord)); 1539 } 1540 1541 // Space committed in the VirtualSpace 1542 size_t VirtualSpaceNode::capacity_words_in_vs() const { 1543 return pointer_delta(end(), bottom(), sizeof(MetaWord)); 1544 } 1545 1546 size_t VirtualSpaceNode::free_words_in_vs() const { 1547 return pointer_delta(end(), top(), sizeof(MetaWord)); 1548 } 1549 1550 // Given an address larger than top(), allocate padding chunks until top is at the given address. 1551 void VirtualSpaceNode::allocate_padding_chunks_until_top_is_at(MetaWord* target_top) { 1552 1553 assert(target_top > top(), "Sanity"); 1554 1555 // Padding chunks are added to the freelist. 1556 ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(this->is_class()); 1557 1558 // shorthands 1559 const size_t spec_word_size = chunk_manager->specialized_chunk_word_size(); 1560 const size_t small_word_size = chunk_manager->small_chunk_word_size(); 1561 const size_t med_word_size = chunk_manager->medium_chunk_word_size(); 1562 1563 while (top() < target_top) { 1564 1565 // We could make this coding more generic, but right now we only deal with two possible chunk sizes 1566 // for padding chunks, so it is not worth it. 1567 size_t padding_chunk_word_size = small_word_size; 1568 if (is_aligned(top(), small_word_size * sizeof(MetaWord)) == false) { 1569 assert_is_aligned(top(), spec_word_size * sizeof(MetaWord)); // Should always hold true. 1570 padding_chunk_word_size = spec_word_size; 1571 } 1572 MetaWord* here = top(); 1573 assert_is_aligned(here, padding_chunk_word_size * sizeof(MetaWord)); 1574 inc_top(padding_chunk_word_size); 1575 1576 // Create new padding chunk. 1577 ChunkIndex padding_chunk_type = get_chunk_type_by_size(padding_chunk_word_size, is_class()); 1578 assert(padding_chunk_type == SpecializedIndex || padding_chunk_type == SmallIndex, "sanity"); 1579 1580 Metachunk* const padding_chunk = 1581 ::new (here) Metachunk(padding_chunk_type, is_class(), padding_chunk_word_size, this); 1582 assert(padding_chunk == (Metachunk*)here, "Sanity"); 1583 DEBUG_ONLY(padding_chunk->set_origin(origin_pad);) 1584 log_trace(gc, metaspace, freelist)("Created padding chunk in %s at " 1585 PTR_FORMAT ", size " SIZE_FORMAT_HEX ".", 1586 (is_class() ? "class space " : "metaspace"), 1587 p2i(padding_chunk), padding_chunk->word_size() * sizeof(MetaWord)); 1588 1589 // Mark chunk start in occupancy map. 1590 occupancy_map()->set_chunk_starts_at_address((MetaWord*)padding_chunk, true); 1591 1592 // Chunks are born as in-use (see MetaChunk ctor). So, before returning 1593 // the padding chunk to its chunk manager, mark it as in use (ChunkManager 1594 // will assert that). 1595 do_update_in_use_info_for_chunk(padding_chunk, true); 1596 1597 // Return Chunk to freelist. 1598 inc_container_count(); 1599 chunk_manager->return_single_chunk(padding_chunk_type, padding_chunk); 1600 // Please note: at this point, ChunkManager::return_single_chunk() 1601 // may already have merged the padding chunk with neighboring chunks, so 1602 // it may have vanished at this point. Do not reference the padding 1603 // chunk beyond this point. 1604 } 1605 1606 assert(top() == target_top, "Sanity"); 1607 1608 } // allocate_padding_chunks_until_top_is_at() 1609 1610 // Allocates the chunk from the virtual space only. 1611 // This interface is also used internally for debugging. Not all 1612 // chunks removed here are necessarily used for allocation. 1613 Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) { 1614 // Non-humongous chunks are to be allocated aligned to their chunk 1615 // size. So, start addresses of medium chunks are aligned to medium 1616 // chunk size, those of small chunks to small chunk size and so 1617 // forth. This facilitates merging of free chunks and reduces 1618 // fragmentation. Chunk sizes are spec < small < medium, with each 1619 // larger chunk size being a multiple of the next smaller chunk 1620 // size. 1621 // Because of this alignment, me may need to create a number of padding 1622 // chunks. These chunks are created and added to the freelist. 1623 1624 // The chunk manager to which we will give our padding chunks. 1625 ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(this->is_class()); 1626 1627 // shorthands 1628 const size_t spec_word_size = chunk_manager->specialized_chunk_word_size(); 1629 const size_t small_word_size = chunk_manager->small_chunk_word_size(); 1630 const size_t med_word_size = chunk_manager->medium_chunk_word_size(); 1631 1632 assert(chunk_word_size == spec_word_size || chunk_word_size == small_word_size || 1633 chunk_word_size >= med_word_size, "Invalid chunk size requested."); 1634 1635 // Chunk alignment (in bytes) == chunk size unless humongous. 1636 // Humongous chunks are aligned to the smallest chunk size (spec). 1637 const size_t required_chunk_alignment = (chunk_word_size > med_word_size ? 1638 spec_word_size : chunk_word_size) * sizeof(MetaWord); 1639 1640 // Do we have enough space to create the requested chunk plus 1641 // any padding chunks needed? 1642 MetaWord* const next_aligned = 1643 static_cast<MetaWord*>(align_up(top(), required_chunk_alignment)); 1644 if (!is_available((next_aligned - top()) + chunk_word_size)) { 1645 return NULL; 1646 } 1647 1648 // Before allocating the requested chunk, allocate padding chunks if necessary. 1649 // We only need to do this for small or medium chunks: specialized chunks are the 1650 // smallest size, hence always aligned. Homungous chunks are allocated unaligned 1651 // (implicitly, also aligned to smallest chunk size). 1652 if ((chunk_word_size == med_word_size || chunk_word_size == small_word_size) && next_aligned > top()) { 1653 log_trace(gc, metaspace, freelist)("Creating padding chunks in %s between %p and %p...", 1654 (is_class() ? "class space " : "metaspace"), 1655 top(), next_aligned); 1656 allocate_padding_chunks_until_top_is_at(next_aligned); 1657 // Now, top should be aligned correctly. 1658 assert_is_aligned(top(), required_chunk_alignment); 1659 } 1660 1661 // Now, top should be aligned correctly. 1662 assert_is_aligned(top(), required_chunk_alignment); 1663 1664 // Bottom of the new chunk 1665 MetaWord* chunk_limit = top(); 1666 assert(chunk_limit != NULL, "Not safe to call this method"); 1667 1668 // The virtual spaces are always expanded by the 1669 // commit granularity to enforce the following condition. 1670 // Without this the is_available check will not work correctly. 1671 assert(_virtual_space.committed_size() == _virtual_space.actual_committed_size(), 1672 "The committed memory doesn't match the expanded memory."); 1673 1674 if (!is_available(chunk_word_size)) { 1675 LogTarget(Debug, gc, metaspace, freelist) lt; 1676 if (lt.is_enabled()) { 1677 LogStream ls(lt); 1678 ls.print("VirtualSpaceNode::take_from_committed() not available " SIZE_FORMAT " words ", chunk_word_size); 1679 // Dump some information about the virtual space that is nearly full 1680 print_on(&ls); 1681 } 1682 return NULL; 1683 } 1684 1685 // Take the space (bump top on the current virtual space). 1686 inc_top(chunk_word_size); 1687 1688 // Initialize the chunk 1689 ChunkIndex chunk_type = get_chunk_type_by_size(chunk_word_size, is_class()); 1690 Metachunk* result = ::new (chunk_limit) Metachunk(chunk_type, is_class(), chunk_word_size, this); 1691 assert(result == (Metachunk*)chunk_limit, "Sanity"); 1692 occupancy_map()->set_chunk_starts_at_address((MetaWord*)result, true); 1693 do_update_in_use_info_for_chunk(result, true); 1694 1695 inc_container_count(); 1696 1697 DEBUG_ONLY(chunk_manager->locked_verify()); 1698 DEBUG_ONLY(this->verify()); 1699 DEBUG_ONLY(do_verify_chunk(result)); 1700 1701 result->inc_use_count(); 1702 1703 return result; 1704 } 1705 1706 1707 // Expand the virtual space (commit more of the reserved space) 1708 bool VirtualSpaceNode::expand_by(size_t min_words, size_t preferred_words) { 1709 size_t min_bytes = min_words * BytesPerWord; 1710 size_t preferred_bytes = preferred_words * BytesPerWord; 1711 1712 size_t uncommitted = virtual_space()->reserved_size() - virtual_space()->actual_committed_size(); 1713 1714 if (uncommitted < min_bytes) { 1715 return false; 1716 } 1717 1718 size_t commit = MIN2(preferred_bytes, uncommitted); 1719 bool result = virtual_space()->expand_by(commit, false); 1720 1721 if (result) { 1722 log_trace(gc, metaspace, freelist)("Expanded %s virtual space list node by " SIZE_FORMAT " words.", 1723 (is_class() ? "class" : "non-class"), commit); 1724 } else { 1725 log_trace(gc, metaspace, freelist)("Failed to expand %s virtual space list node by " SIZE_FORMAT " words.", 1726 (is_class() ? "class" : "non-class"), commit); 1727 } 1728 1729 assert(result, "Failed to commit memory"); 1730 1731 return result; 1732 } 1733 1734 Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) { 1735 assert_lock_strong(SpaceManager::expand_lock()); 1736 Metachunk* result = take_from_committed(chunk_word_size); 1737 return result; 1738 } 1739 1740 bool VirtualSpaceNode::initialize() { 1741 1742 if (!_rs.is_reserved()) { 1743 return false; 1744 } 1745 1746 // These are necessary restriction to make sure that the virtual space always 1747 // grows in steps of Metaspace::commit_alignment(). If both base and size are 1748 // aligned only the middle alignment of the VirtualSpace is used. 1749 assert_is_aligned(_rs.base(), Metaspace::commit_alignment()); 1750 assert_is_aligned(_rs.size(), Metaspace::commit_alignment()); 1751 1752 // ReservedSpaces marked as special will have the entire memory 1753 // pre-committed. Setting a committed size will make sure that 1754 // committed_size and actual_committed_size agrees. 1755 size_t pre_committed_size = _rs.special() ? _rs.size() : 0; 1756 1757 bool result = virtual_space()->initialize_with_granularity(_rs, pre_committed_size, 1758 Metaspace::commit_alignment()); 1759 if (result) { 1760 assert(virtual_space()->committed_size() == virtual_space()->actual_committed_size(), 1761 "Checking that the pre-committed memory was registered by the VirtualSpace"); 1762 1763 set_top((MetaWord*)virtual_space()->low()); 1764 set_reserved(MemRegion((HeapWord*)_rs.base(), 1765 (HeapWord*)(_rs.base() + _rs.size()))); 1766 1767 assert(reserved()->start() == (HeapWord*) _rs.base(), 1768 "Reserved start was not set properly " PTR_FORMAT 1769 " != " PTR_FORMAT, p2i(reserved()->start()), p2i(_rs.base())); 1770 assert(reserved()->word_size() == _rs.size() / BytesPerWord, 1771 "Reserved size was not set properly " SIZE_FORMAT 1772 " != " SIZE_FORMAT, reserved()->word_size(), 1773 _rs.size() / BytesPerWord); 1774 } 1775 1776 // Initialize Occupancy Map. 1777 const size_t smallest_chunk_size = is_class() ? ClassSpecializedChunk : SpecializedChunk; 1778 _occupancy_map = new OccupancyMap(bottom(), reserved_words(), smallest_chunk_size); 1779 1780 return result; 1781 } 1782 1783 void VirtualSpaceNode::print_on(outputStream* st) const { 1784 size_t used = used_words_in_vs(); 1785 size_t capacity = capacity_words_in_vs(); 1786 VirtualSpace* vs = virtual_space(); 1787 st->print_cr(" space @ " PTR_FORMAT " " SIZE_FORMAT "K, " SIZE_FORMAT_W(3) "%% used " 1788 "[" PTR_FORMAT ", " PTR_FORMAT ", " 1789 PTR_FORMAT ", " PTR_FORMAT ")", 1790 p2i(vs), capacity / K, 1791 capacity == 0 ? 0 : used * 100 / capacity, 1792 p2i(bottom()), p2i(top()), p2i(end()), 1793 p2i(vs->high_boundary())); 1794 } 1795 1796 #ifdef ASSERT 1797 void VirtualSpaceNode::mangle() { 1798 size_t word_size = capacity_words_in_vs(); 1799 Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1); 1800 } 1801 #endif // ASSERT 1802 1803 // VirtualSpaceList methods 1804 // Space allocated from the VirtualSpace 1805 1806 VirtualSpaceList::~VirtualSpaceList() { 1807 VirtualSpaceListIterator iter(virtual_space_list()); 1808 while (iter.repeat()) { 1809 VirtualSpaceNode* vsl = iter.get_next(); 1810 delete vsl; 1811 } 1812 } 1813 1814 void VirtualSpaceList::inc_reserved_words(size_t v) { 1815 assert_lock_strong(SpaceManager::expand_lock()); 1816 _reserved_words = _reserved_words + v; 1817 } 1818 void VirtualSpaceList::dec_reserved_words(size_t v) { 1819 assert_lock_strong(SpaceManager::expand_lock()); 1820 _reserved_words = _reserved_words - v; 1821 } 1822 1823 #define assert_committed_below_limit() \ 1824 assert(MetaspaceAux::committed_bytes() <= MaxMetaspaceSize, \ 1825 "Too much committed memory. Committed: " SIZE_FORMAT \ 1826 " limit (MaxMetaspaceSize): " SIZE_FORMAT, \ 1827 MetaspaceAux::committed_bytes(), MaxMetaspaceSize); 1828 1829 void VirtualSpaceList::inc_committed_words(size_t v) { 1830 assert_lock_strong(SpaceManager::expand_lock()); 1831 _committed_words = _committed_words + v; 1832 1833 assert_committed_below_limit(); 1834 } 1835 void VirtualSpaceList::dec_committed_words(size_t v) { 1836 assert_lock_strong(SpaceManager::expand_lock()); 1837 _committed_words = _committed_words - v; 1838 1839 assert_committed_below_limit(); 1840 } 1841 1842 void VirtualSpaceList::inc_virtual_space_count() { 1843 assert_lock_strong(SpaceManager::expand_lock()); 1844 _virtual_space_count++; 1845 } 1846 void VirtualSpaceList::dec_virtual_space_count() { 1847 assert_lock_strong(SpaceManager::expand_lock()); 1848 _virtual_space_count--; 1849 } 1850 1851 void ChunkManager::remove_chunk(Metachunk* chunk) { 1852 size_t word_size = chunk->word_size(); 1853 ChunkIndex index = list_index(word_size); 1854 if (index != HumongousIndex) { 1855 free_chunks(index)->remove_chunk(chunk); 1856 } else { 1857 humongous_dictionary()->remove_chunk(chunk); 1858 } 1859 1860 // Chunk has been removed from the chunks free list, update counters. 1861 account_for_removed_chunk(chunk); 1862 } 1863 1864 bool ChunkManager::attempt_to_coalesce_around_chunk(Metachunk* chunk, ChunkIndex target_chunk_type) { 1865 assert_lock_strong(SpaceManager::expand_lock()); 1866 assert(chunk != NULL, "invalid chunk pointer"); 1867 // Check for valid merge combinations. 1868 assert((chunk->get_chunk_type() == SpecializedIndex && 1869 (target_chunk_type == SmallIndex || target_chunk_type == MediumIndex)) || 1870 (chunk->get_chunk_type() == SmallIndex && target_chunk_type == MediumIndex), 1871 "Invalid chunk merge combination."); 1872 1873 const size_t target_chunk_word_size = 1874 get_size_for_nonhumongous_chunktype(target_chunk_type, this->is_class()); 1875 1876 // [ prospective merge region ) 1877 MetaWord* const p_merge_region_start = 1878 (MetaWord*) align_down(chunk, target_chunk_word_size * sizeof(MetaWord)); 1879 MetaWord* const p_merge_region_end = 1880 p_merge_region_start + target_chunk_word_size; 1881 1882 // We need the VirtualSpaceNode containing this chunk and its occupancy map. 1883 VirtualSpaceNode* const vsn = chunk->container(); 1884 OccupancyMap* const ocmap = vsn->occupancy_map(); 1885 1886 // The prospective chunk merge range must be completely contained by the 1887 // committed range of the virtual space node. 1888 if (p_merge_region_start < vsn->bottom() || p_merge_region_end > vsn->top()) { 1889 return false; 1890 } 1891 1892 // Only attempt to merge this range if at its start a chunk starts and at its end 1893 // a chunk ends. If a chunk (can only be humongous) straddles either start or end 1894 // of that range, we cannot merge. 1895 if (!ocmap->chunk_starts_at_address(p_merge_region_start)) { 1896 return false; 1897 } 1898 if (p_merge_region_end < vsn->top() && 1899 !ocmap->chunk_starts_at_address(p_merge_region_end)) { 1900 return false; 1901 } 1902 1903 // Now check if the prospective merge area contains live chunks. If it does we cannot merge. 1904 if (ocmap->is_region_in_use(p_merge_region_start, target_chunk_word_size)) { 1905 return false; 1906 } 1907 1908 // Success! Remove all chunks in this region... 1909 log_trace(gc, metaspace, freelist)("%s: coalescing chunks in area [%p-%p)...", 1910 (is_class() ? "class space" : "metaspace"), 1911 p_merge_region_start, p_merge_region_end); 1912 1913 const int num_chunks_removed = 1914 remove_chunks_in_area(p_merge_region_start, target_chunk_word_size); 1915 1916 // ... and create a single new bigger chunk. 1917 Metachunk* const p_new_chunk = 1918 ::new (p_merge_region_start) Metachunk(target_chunk_type, is_class(), target_chunk_word_size, vsn); 1919 assert(p_new_chunk == (Metachunk*)p_merge_region_start, "Sanity"); 1920 p_new_chunk->set_origin(origin_merge); 1921 1922 log_trace(gc, metaspace, freelist)("%s: created coalesced chunk at %p, size " SIZE_FORMAT_HEX ".", 1923 (is_class() ? "class space" : "metaspace"), 1924 p_new_chunk, p_new_chunk->word_size() * sizeof(MetaWord)); 1925 1926 // Fix occupancy map: remove old start bits of the small chunks and set new start bit. 1927 ocmap->wipe_chunk_start_bits_in_region(p_merge_region_start, target_chunk_word_size); 1928 ocmap->set_chunk_starts_at_address(p_merge_region_start, true); 1929 1930 // Mark chunk as free. Note: it is not necessary to update the occupancy 1931 // map in-use map, because the old chunks were also free, so nothing 1932 // should have changed. 1933 p_new_chunk->set_is_tagged_free(true); 1934 1935 // Add new chunk to its freelist. 1936 ChunkList* const list = free_chunks(target_chunk_type); 1937 list->return_chunk_at_head(p_new_chunk); 1938 1939 // And adjust ChunkManager:: _free_chunks_count (_free_chunks_total 1940 // should not have changed, because the size of the space should be the same) 1941 _free_chunks_count -= num_chunks_removed; 1942 _free_chunks_count ++; 1943 1944 // VirtualSpaceNode::container_count does not have to be modified: 1945 // it means "number of active (non-free) chunks", so merging free chunks 1946 // should not affect that count. 1947 1948 // At the end of a chunk merge, run verification tests. 1949 DEBUG_ONLY(this->locked_verify()); 1950 DEBUG_ONLY(vsn->verify()); 1951 1952 return true; 1953 } 1954 1955 // Remove all chunks in the given area - the chunks are supposed to be free - 1956 // from their corresponding freelists. Mark them as invalid. 1957 // - This does not correct the occupancy map. 1958 // - This does not adjust the counters in ChunkManager. 1959 // - Does not adjust container count counter in containing VirtualSpaceNode 1960 // Returns number of chunks removed. 1961 int ChunkManager::remove_chunks_in_area(MetaWord* p, size_t word_size) { 1962 assert(p != NULL && word_size > 0, "Invalid range."); 1963 const size_t smallest_chunk_size = get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class()); 1964 assert_is_aligned(word_size, smallest_chunk_size); 1965 1966 Metachunk* const start = (Metachunk*) p; 1967 const Metachunk* const end = (Metachunk*)(p + word_size); 1968 Metachunk* cur = start; 1969 int num_removed = 0; 1970 while (cur < end) { 1971 Metachunk* next = (Metachunk*)(((MetaWord*)cur) + cur->word_size()); 1972 DEBUG_ONLY(do_verify_chunk(cur)); 1973 assert(cur->get_chunk_type() != HumongousIndex, "Unexpected humongous chunk found at %p.", cur); 1974 assert(cur->is_tagged_free(), "Chunk expected to be free (%p)", cur); 1975 log_trace(gc, metaspace, freelist)("%s: removing chunk %p, size " SIZE_FORMAT_HEX ".", 1976 (is_class() ? "class space" : "metaspace"), 1977 cur, cur->word_size() * sizeof(MetaWord)); 1978 cur->remove_sentinel(); 1979 // Note: cannot call ChunkManager::remove_chunk, because that 1980 // modifies the counters in ChunkManager, which we do not want. So 1981 // we call remove_chunk on the freelist directly (see also the 1982 // splitting function which does the same). 1983 ChunkList* const list = free_chunks(list_index(cur->word_size())); 1984 list->remove_chunk(cur); 1985 num_removed ++; 1986 cur = next; 1987 } 1988 return num_removed; 1989 } 1990 1991 // Walk the list of VirtualSpaceNodes and delete 1992 // nodes with a 0 container_count. Remove Metachunks in 1993 // the node from their respective freelists. 1994 void VirtualSpaceList::purge(ChunkManager* chunk_manager) { 1995 assert(SafepointSynchronize::is_at_safepoint(), "must be called at safepoint for contains to work"); 1996 assert_lock_strong(SpaceManager::expand_lock()); 1997 // Don't use a VirtualSpaceListIterator because this 1998 // list is being changed and a straightforward use of an iterator is not safe. 1999 VirtualSpaceNode* purged_vsl = NULL; 2000 VirtualSpaceNode* prev_vsl = virtual_space_list(); 2001 VirtualSpaceNode* next_vsl = prev_vsl; 2002 while (next_vsl != NULL) { 2003 VirtualSpaceNode* vsl = next_vsl; 2004 DEBUG_ONLY(vsl->verify_container_count();) 2005 next_vsl = vsl->next(); 2006 // Don't free the current virtual space since it will likely 2007 // be needed soon. 2008 if (vsl->container_count() == 0 && vsl != current_virtual_space()) { 2009 log_trace(gc, metaspace, freelist)("Purging VirtualSpaceNode " PTR_FORMAT " (capacity: " SIZE_FORMAT 2010 ", used: " SIZE_FORMAT ").", p2i(vsl), vsl->capacity_words_in_vs(), vsl->used_words_in_vs()); 2011 // Unlink it from the list 2012 if (prev_vsl == vsl) { 2013 // This is the case of the current node being the first node. 2014 assert(vsl == virtual_space_list(), "Expected to be the first node"); 2015 set_virtual_space_list(vsl->next()); 2016 } else { 2017 prev_vsl->set_next(vsl->next()); 2018 } 2019 2020 vsl->purge(chunk_manager); 2021 dec_reserved_words(vsl->reserved_words()); 2022 dec_committed_words(vsl->committed_words()); 2023 dec_virtual_space_count(); 2024 purged_vsl = vsl; 2025 delete vsl; 2026 } else { 2027 prev_vsl = vsl; 2028 } 2029 } 2030 #ifdef ASSERT 2031 if (purged_vsl != NULL) { 2032 // List should be stable enough to use an iterator here. 2033 VirtualSpaceListIterator iter(virtual_space_list()); 2034 while (iter.repeat()) { 2035 VirtualSpaceNode* vsl = iter.get_next(); 2036 assert(vsl != purged_vsl, "Purge of vsl failed"); 2037 } 2038 } 2039 #endif 2040 } 2041 2042 2043 // This function looks at the mmap regions in the metaspace without locking. 2044 // The chunks are added with store ordering and not deleted except for at 2045 // unloading time during a safepoint. 2046 bool VirtualSpaceList::contains(const void* ptr) { 2047 // List should be stable enough to use an iterator here because removing virtual 2048 // space nodes is only allowed at a safepoint. 2049 VirtualSpaceListIterator iter(virtual_space_list()); 2050 while (iter.repeat()) { 2051 VirtualSpaceNode* vsn = iter.get_next(); 2052 if (vsn->contains(ptr)) { 2053 return true; 2054 } 2055 } 2056 return false; 2057 } 2058 2059 void VirtualSpaceList::retire_current_virtual_space() { 2060 assert_lock_strong(SpaceManager::expand_lock()); 2061 2062 VirtualSpaceNode* vsn = current_virtual_space(); 2063 2064 ChunkManager* cm = is_class() ? Metaspace::chunk_manager_class() : 2065 Metaspace::chunk_manager_metadata(); 2066 2067 vsn->retire(cm); 2068 } 2069 2070 void VirtualSpaceNode::retire(ChunkManager* chunk_manager) { 2071 DEBUG_ONLY(verify_container_count();) 2072 assert(this->is_class() == chunk_manager->is_class(), "Wrong ChunkManager?"); 2073 for (int i = (int)MediumIndex; i >= (int)ZeroIndex; --i) { 2074 ChunkIndex index = (ChunkIndex)i; 2075 size_t chunk_size = chunk_manager->size_by_index(index); 2076 2077 while (free_words_in_vs() >= chunk_size) { 2078 Metachunk* chunk = get_chunk_vs(chunk_size); 2079 // Chunk will be allocated aligned, so allocation may require 2080 // additional padding chunks. That may cause above allocation to 2081 // fail. Just ignore the failed allocation and continue with the 2082 // next smaller chunk size. As the VirtualSpaceNode comitted 2083 // size should be a multiple of the smallest chunk size, we 2084 // should always be able to fill the VirtualSpace completely. 2085 if (chunk == NULL) { 2086 break; 2087 } 2088 chunk_manager->return_single_chunk(index, chunk); 2089 } 2090 DEBUG_ONLY(verify_container_count();) 2091 } 2092 assert(free_words_in_vs() == 0, "should be empty now"); 2093 } 2094 2095 VirtualSpaceList::VirtualSpaceList(size_t word_size) : 2096 _is_class(false), 2097 _virtual_space_list(NULL), 2098 _current_virtual_space(NULL), 2099 _reserved_words(0), 2100 _committed_words(0), 2101 _virtual_space_count(0) { 2102 MutexLockerEx cl(SpaceManager::expand_lock(), 2103 Mutex::_no_safepoint_check_flag); 2104 create_new_virtual_space(word_size); 2105 } 2106 2107 VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) : 2108 _is_class(true), 2109 _virtual_space_list(NULL), 2110 _current_virtual_space(NULL), 2111 _reserved_words(0), 2112 _committed_words(0), 2113 _virtual_space_count(0) { 2114 MutexLockerEx cl(SpaceManager::expand_lock(), 2115 Mutex::_no_safepoint_check_flag); 2116 VirtualSpaceNode* class_entry = new VirtualSpaceNode(is_class(), rs); 2117 bool succeeded = class_entry->initialize(); 2118 if (succeeded) { 2119 link_vs(class_entry); 2120 } 2121 } 2122 2123 size_t VirtualSpaceList::free_bytes() { 2124 return current_virtual_space()->free_words_in_vs() * BytesPerWord; 2125 } 2126 2127 // Allocate another meta virtual space and add it to the list. 2128 bool VirtualSpaceList::create_new_virtual_space(size_t vs_word_size) { 2129 assert_lock_strong(SpaceManager::expand_lock()); 2130 2131 if (is_class()) { 2132 assert(false, "We currently don't support more than one VirtualSpace for" 2133 " the compressed class space. The initialization of the" 2134 " CCS uses another code path and should not hit this path."); 2135 return false; 2136 } 2137 2138 if (vs_word_size == 0) { 2139 assert(false, "vs_word_size should always be at least _reserve_alignment large."); 2140 return false; 2141 } 2142 2143 // Reserve the space 2144 size_t vs_byte_size = vs_word_size * BytesPerWord; 2145 assert_is_aligned(vs_byte_size, Metaspace::reserve_alignment()); 2146 2147 // Allocate the meta virtual space and initialize it. 2148 VirtualSpaceNode* new_entry = new VirtualSpaceNode(is_class(), vs_byte_size); 2149 if (!new_entry->initialize()) { 2150 delete new_entry; 2151 return false; 2152 } else { 2153 assert(new_entry->reserved_words() == vs_word_size, 2154 "Reserved memory size differs from requested memory size"); 2155 // ensure lock-free iteration sees fully initialized node 2156 OrderAccess::storestore(); 2157 link_vs(new_entry); 2158 return true; 2159 } 2160 } 2161 2162 void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry) { 2163 if (virtual_space_list() == NULL) { 2164 set_virtual_space_list(new_entry); 2165 } else { 2166 current_virtual_space()->set_next(new_entry); 2167 } 2168 set_current_virtual_space(new_entry); 2169 inc_reserved_words(new_entry->reserved_words()); 2170 inc_committed_words(new_entry->committed_words()); 2171 inc_virtual_space_count(); 2172 #ifdef ASSERT 2173 new_entry->mangle(); 2174 #endif 2175 LogTarget(Trace, gc, metaspace) lt; 2176 if (lt.is_enabled()) { 2177 LogStream ls(lt); 2178 VirtualSpaceNode* vsl = current_virtual_space(); 2179 ResourceMark rm; 2180 vsl->print_on(&ls); 2181 } 2182 } 2183 2184 bool VirtualSpaceList::expand_node_by(VirtualSpaceNode* node, 2185 size_t min_words, 2186 size_t preferred_words) { 2187 size_t before = node->committed_words(); 2188 2189 bool result = node->expand_by(min_words, preferred_words); 2190 2191 size_t after = node->committed_words(); 2192 2193 // after and before can be the same if the memory was pre-committed. 2194 assert(after >= before, "Inconsistency"); 2195 inc_committed_words(after - before); 2196 2197 return result; 2198 } 2199 2200 bool VirtualSpaceList::expand_by(size_t min_words, size_t preferred_words) { 2201 assert_is_aligned(min_words, Metaspace::commit_alignment_words()); 2202 assert_is_aligned(preferred_words, Metaspace::commit_alignment_words()); 2203 assert(min_words <= preferred_words, "Invalid arguments"); 2204 2205 const char* const class_or_not = (is_class() ? "class" : "non-class"); 2206 2207 if (!MetaspaceGC::can_expand(min_words, this->is_class())) { 2208 log_trace(gc, metaspace, freelist)("Cannot expand %s virtual space list.", 2209 class_or_not); 2210 return false; 2211 } 2212 2213 size_t allowed_expansion_words = MetaspaceGC::allowed_expansion(); 2214 if (allowed_expansion_words < min_words) { 2215 log_trace(gc, metaspace, freelist)("Cannot expand %s virtual space list (must try gc first).", 2216 class_or_not); 2217 return false; 2218 } 2219 2220 size_t max_expansion_words = MIN2(preferred_words, allowed_expansion_words); 2221 2222 // Commit more memory from the the current virtual space. 2223 bool vs_expanded = expand_node_by(current_virtual_space(), 2224 min_words, 2225 max_expansion_words); 2226 if (vs_expanded) { 2227 log_trace(gc, metaspace, freelist)("Expanded %s virtual space list.", 2228 class_or_not); 2229 return true; 2230 } 2231 log_trace(gc, metaspace, freelist)("%s virtual space list: retire current node.", 2232 class_or_not); 2233 retire_current_virtual_space(); 2234 2235 // Get another virtual space. 2236 size_t grow_vs_words = MAX2((size_t)VirtualSpaceSize, preferred_words); 2237 grow_vs_words = align_up(grow_vs_words, Metaspace::reserve_alignment_words()); 2238 2239 if (create_new_virtual_space(grow_vs_words)) { 2240 if (current_virtual_space()->is_pre_committed()) { 2241 // The memory was pre-committed, so we are done here. 2242 assert(min_words <= current_virtual_space()->committed_words(), 2243 "The new VirtualSpace was pre-committed, so it" 2244 "should be large enough to fit the alloc request."); 2245 return true; 2246 } 2247 2248 return expand_node_by(current_virtual_space(), 2249 min_words, 2250 max_expansion_words); 2251 } 2252 2253 return false; 2254 } 2255 2256 // Given a chunk, calculate the largest possible padding space which 2257 // could be required when allocating it. 2258 static size_t largest_possible_padding_size_for_chunk(size_t chunk_word_size, bool is_class) { 2259 const ChunkIndex chunk_type = get_chunk_type_by_size(chunk_word_size, is_class); 2260 if (chunk_type != HumongousIndex) { 2261 // Normal, non-humongous chunks are allocated at chunk size 2262 // boundaries, so the largest padding space required would be that 2263 // minus the smallest chunk size. 2264 const size_t smallest_chunk_size = is_class ? ClassSpecializedChunk : SpecializedChunk; 2265 return chunk_word_size - smallest_chunk_size; 2266 } else { 2267 // Humongous chunks are allocated at smallest-chunksize 2268 // boundaries, so there is no padding required. 2269 return 0; 2270 } 2271 } 2272 2273 2274 Metachunk* VirtualSpaceList::get_new_chunk(size_t chunk_word_size, size_t suggested_commit_granularity) { 2275 2276 // Allocate a chunk out of the current virtual space. 2277 Metachunk* next = current_virtual_space()->get_chunk_vs(chunk_word_size); 2278 2279 if (next != NULL) { 2280 return next; 2281 } 2282 2283 // The expand amount is currently only determined by the requested sizes 2284 // and not how much committed memory is left in the current virtual space. 2285 2286 // We must have enough space for the requested size and any 2287 // additional reqired padding chunks. 2288 const size_t size_for_padding = largest_possible_padding_size_for_chunk(chunk_word_size, this->is_class()); 2289 2290 size_t min_word_size = align_up(chunk_word_size + size_for_padding, Metaspace::commit_alignment_words()); 2291 size_t preferred_word_size = align_up(suggested_commit_granularity, Metaspace::commit_alignment_words()); 2292 if (min_word_size >= preferred_word_size) { 2293 // Can happen when humongous chunks are allocated. 2294 preferred_word_size = min_word_size; 2295 } 2296 2297 bool expanded = expand_by(min_word_size, preferred_word_size); 2298 if (expanded) { 2299 next = current_virtual_space()->get_chunk_vs(chunk_word_size); 2300 assert(next != NULL, "The allocation was expected to succeed after the expansion"); 2301 } 2302 2303 return next; 2304 } 2305 2306 void VirtualSpaceList::print_on(outputStream* st) const { 2307 VirtualSpaceListIterator iter(virtual_space_list()); 2308 while (iter.repeat()) { 2309 VirtualSpaceNode* node = iter.get_next(); 2310 node->print_on(st); 2311 } 2312 } 2313 2314 void VirtualSpaceList::print_map(outputStream* st) const { 2315 VirtualSpaceNode* list = virtual_space_list(); 2316 VirtualSpaceListIterator iter(list); 2317 unsigned i = 0; 2318 while (iter.repeat()) { 2319 st->print_cr("Node %u:", i); 2320 VirtualSpaceNode* node = iter.get_next(); 2321 node->print_map(st, this->is_class()); 2322 i ++; 2323 } 2324 } 2325 2326 // MetaspaceGC methods 2327 2328 // VM_CollectForMetadataAllocation is the vm operation used to GC. 2329 // Within the VM operation after the GC the attempt to allocate the metadata 2330 // should succeed. If the GC did not free enough space for the metaspace 2331 // allocation, the HWM is increased so that another virtualspace will be 2332 // allocated for the metadata. With perm gen the increase in the perm 2333 // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion. The 2334 // metaspace policy uses those as the small and large steps for the HWM. 2335 // 2336 // After the GC the compute_new_size() for MetaspaceGC is called to 2337 // resize the capacity of the metaspaces. The current implementation 2338 // is based on the flags MinMetaspaceFreeRatio and MaxMetaspaceFreeRatio used 2339 // to resize the Java heap by some GC's. New flags can be implemented 2340 // if really needed. MinMetaspaceFreeRatio is used to calculate how much 2341 // free space is desirable in the metaspace capacity to decide how much 2342 // to increase the HWM. MaxMetaspaceFreeRatio is used to decide how much 2343 // free space is desirable in the metaspace capacity before decreasing 2344 // the HWM. 2345 2346 // Calculate the amount to increase the high water mark (HWM). 2347 // Increase by a minimum amount (MinMetaspaceExpansion) so that 2348 // another expansion is not requested too soon. If that is not 2349 // enough to satisfy the allocation, increase by MaxMetaspaceExpansion. 2350 // If that is still not enough, expand by the size of the allocation 2351 // plus some. 2352 size_t MetaspaceGC::delta_capacity_until_GC(size_t bytes) { 2353 size_t min_delta = MinMetaspaceExpansion; 2354 size_t max_delta = MaxMetaspaceExpansion; 2355 size_t delta = align_up(bytes, Metaspace::commit_alignment()); 2356 2357 if (delta <= min_delta) { 2358 delta = min_delta; 2359 } else if (delta <= max_delta) { 2360 // Don't want to hit the high water mark on the next 2361 // allocation so make the delta greater than just enough 2362 // for this allocation. 2363 delta = max_delta; 2364 } else { 2365 // This allocation is large but the next ones are probably not 2366 // so increase by the minimum. 2367 delta = delta + min_delta; 2368 } 2369 2370 assert_is_aligned(delta, Metaspace::commit_alignment()); 2371 2372 return delta; 2373 } 2374 2375 size_t MetaspaceGC::capacity_until_GC() { 2376 size_t value = OrderAccess::load_acquire(&_capacity_until_GC); 2377 assert(value >= MetaspaceSize, "Not initialized properly?"); 2378 return value; 2379 } 2380 2381 bool MetaspaceGC::inc_capacity_until_GC(size_t v, size_t* new_cap_until_GC, size_t* old_cap_until_GC) { 2382 assert_is_aligned(v, Metaspace::commit_alignment()); 2383 2384 intptr_t capacity_until_GC = _capacity_until_GC; 2385 intptr_t new_value = capacity_until_GC + v; 2386 2387 if (new_value < capacity_until_GC) { 2388 // The addition wrapped around, set new_value to aligned max value. 2389 new_value = align_down(max_uintx, Metaspace::commit_alignment()); 2390 } 2391 2392 intptr_t expected = _capacity_until_GC; 2393 intptr_t actual = Atomic::cmpxchg(new_value, &_capacity_until_GC, expected); 2394 2395 if (expected != actual) { 2396 return false; 2397 } 2398 2399 if (new_cap_until_GC != NULL) { 2400 *new_cap_until_GC = new_value; 2401 } 2402 if (old_cap_until_GC != NULL) { 2403 *old_cap_until_GC = capacity_until_GC; 2404 } 2405 return true; 2406 } 2407 2408 size_t MetaspaceGC::dec_capacity_until_GC(size_t v) { 2409 assert_is_aligned(v, Metaspace::commit_alignment()); 2410 2411 return (size_t)Atomic::sub((intptr_t)v, &_capacity_until_GC); 2412 } 2413 2414 void MetaspaceGC::initialize() { 2415 // Set the high-water mark to MaxMetapaceSize during VM initializaton since 2416 // we can't do a GC during initialization. 2417 _capacity_until_GC = MaxMetaspaceSize; 2418 } 2419 2420 void MetaspaceGC::post_initialize() { 2421 // Reset the high-water mark once the VM initialization is done. 2422 _capacity_until_GC = MAX2(MetaspaceAux::committed_bytes(), MetaspaceSize); 2423 } 2424 2425 bool MetaspaceGC::can_expand(size_t word_size, bool is_class) { 2426 // Check if the compressed class space is full. 2427 if (is_class && Metaspace::using_class_space()) { 2428 size_t class_committed = MetaspaceAux::committed_bytes(Metaspace::ClassType); 2429 if (class_committed + word_size * BytesPerWord > CompressedClassSpaceSize) { 2430 log_trace(gc, metaspace, freelist)("Cannot expand %s metaspace by " SIZE_FORMAT " words (CompressedClassSpaceSize = " SIZE_FORMAT " words)", 2431 (is_class ? "class" : "non-class"), word_size, CompressedClassSpaceSize / sizeof(MetaWord)); 2432 return false; 2433 } 2434 } 2435 2436 // Check if the user has imposed a limit on the metaspace memory. 2437 size_t committed_bytes = MetaspaceAux::committed_bytes(); 2438 if (committed_bytes + word_size * BytesPerWord > MaxMetaspaceSize) { 2439 log_trace(gc, metaspace, freelist)("Cannot expand %s metaspace by " SIZE_FORMAT " words (MaxMetaspaceSize = " SIZE_FORMAT " words)", 2440 (is_class ? "class" : "non-class"), word_size, MaxMetaspaceSize / sizeof(MetaWord)); 2441 return false; 2442 } 2443 2444 return true; 2445 } 2446 2447 size_t MetaspaceGC::allowed_expansion() { 2448 size_t committed_bytes = MetaspaceAux::committed_bytes(); 2449 size_t capacity_until_gc = capacity_until_GC(); 2450 2451 assert(capacity_until_gc >= committed_bytes, 2452 "capacity_until_gc: " SIZE_FORMAT " < committed_bytes: " SIZE_FORMAT, 2453 capacity_until_gc, committed_bytes); 2454 2455 size_t left_until_max = MaxMetaspaceSize - committed_bytes; 2456 size_t left_until_GC = capacity_until_gc - committed_bytes; 2457 size_t left_to_commit = MIN2(left_until_GC, left_until_max); 2458 log_trace(gc, metaspace, freelist)("allowed expansion words: " SIZE_FORMAT 2459 " (left_until_max: " SIZE_FORMAT ", left_until_GC: " SIZE_FORMAT ".", 2460 left_to_commit / BytesPerWord, left_until_max / BytesPerWord, left_until_GC / BytesPerWord); 2461 2462 return left_to_commit / BytesPerWord; 2463 } 2464 2465 void MetaspaceGC::compute_new_size() { 2466 assert(_shrink_factor <= 100, "invalid shrink factor"); 2467 uint current_shrink_factor = _shrink_factor; 2468 _shrink_factor = 0; 2469 2470 // Using committed_bytes() for used_after_gc is an overestimation, since the 2471 // chunk free lists are included in committed_bytes() and the memory in an 2472 // un-fragmented chunk free list is available for future allocations. 2473 // However, if the chunk free lists becomes fragmented, then the memory may 2474 // not be available for future allocations and the memory is therefore "in use". 2475 // Including the chunk free lists in the definition of "in use" is therefore 2476 // necessary. Not including the chunk free lists can cause capacity_until_GC to 2477 // shrink below committed_bytes() and this has caused serious bugs in the past. 2478 const size_t used_after_gc = MetaspaceAux::committed_bytes(); 2479 const size_t capacity_until_GC = MetaspaceGC::capacity_until_GC(); 2480 2481 const double minimum_free_percentage = MinMetaspaceFreeRatio / 100.0; 2482 const double maximum_used_percentage = 1.0 - minimum_free_percentage; 2483 2484 const double min_tmp = used_after_gc / maximum_used_percentage; 2485 size_t minimum_desired_capacity = 2486 (size_t)MIN2(min_tmp, double(max_uintx)); 2487 // Don't shrink less than the initial generation size 2488 minimum_desired_capacity = MAX2(minimum_desired_capacity, 2489 MetaspaceSize); 2490 2491 log_trace(gc, metaspace)("MetaspaceGC::compute_new_size: "); 2492 log_trace(gc, metaspace)(" minimum_free_percentage: %6.2f maximum_used_percentage: %6.2f", 2493 minimum_free_percentage, maximum_used_percentage); 2494 log_trace(gc, metaspace)(" used_after_gc : %6.1fKB", used_after_gc / (double) K); 2495 2496 2497 size_t shrink_bytes = 0; 2498 if (capacity_until_GC < minimum_desired_capacity) { 2499 // If we have less capacity below the metaspace HWM, then 2500 // increment the HWM. 2501 size_t expand_bytes = minimum_desired_capacity - capacity_until_GC; 2502 expand_bytes = align_up(expand_bytes, Metaspace::commit_alignment()); 2503 // Don't expand unless it's significant 2504 if (expand_bytes >= MinMetaspaceExpansion) { 2505 size_t new_capacity_until_GC = 0; 2506 bool succeeded = MetaspaceGC::inc_capacity_until_GC(expand_bytes, &new_capacity_until_GC); 2507 assert(succeeded, "Should always succesfully increment HWM when at safepoint"); 2508 2509 Metaspace::tracer()->report_gc_threshold(capacity_until_GC, 2510 new_capacity_until_GC, 2511 MetaspaceGCThresholdUpdater::ComputeNewSize); 2512 log_trace(gc, metaspace)(" expanding: minimum_desired_capacity: %6.1fKB expand_bytes: %6.1fKB MinMetaspaceExpansion: %6.1fKB new metaspace HWM: %6.1fKB", 2513 minimum_desired_capacity / (double) K, 2514 expand_bytes / (double) K, 2515 MinMetaspaceExpansion / (double) K, 2516 new_capacity_until_GC / (double) K); 2517 } 2518 return; 2519 } 2520 2521 // No expansion, now see if we want to shrink 2522 // We would never want to shrink more than this 2523 assert(capacity_until_GC >= minimum_desired_capacity, 2524 SIZE_FORMAT " >= " SIZE_FORMAT, 2525 capacity_until_GC, minimum_desired_capacity); 2526 size_t max_shrink_bytes = capacity_until_GC - minimum_desired_capacity; 2527 2528 // Should shrinking be considered? 2529 if (MaxMetaspaceFreeRatio < 100) { 2530 const double maximum_free_percentage = MaxMetaspaceFreeRatio / 100.0; 2531 const double minimum_used_percentage = 1.0 - maximum_free_percentage; 2532 const double max_tmp = used_after_gc / minimum_used_percentage; 2533 size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx)); 2534 maximum_desired_capacity = MAX2(maximum_desired_capacity, 2535 MetaspaceSize); 2536 log_trace(gc, metaspace)(" maximum_free_percentage: %6.2f minimum_used_percentage: %6.2f", 2537 maximum_free_percentage, minimum_used_percentage); 2538 log_trace(gc, metaspace)(" minimum_desired_capacity: %6.1fKB maximum_desired_capacity: %6.1fKB", 2539 minimum_desired_capacity / (double) K, maximum_desired_capacity / (double) K); 2540 2541 assert(minimum_desired_capacity <= maximum_desired_capacity, 2542 "sanity check"); 2543 2544 if (capacity_until_GC > maximum_desired_capacity) { 2545 // Capacity too large, compute shrinking size 2546 shrink_bytes = capacity_until_GC - maximum_desired_capacity; 2547 // We don't want shrink all the way back to initSize if people call 2548 // System.gc(), because some programs do that between "phases" and then 2549 // we'd just have to grow the heap up again for the next phase. So we 2550 // damp the shrinking: 0% on the first call, 10% on the second call, 40% 2551 // on the third call, and 100% by the fourth call. But if we recompute 2552 // size without shrinking, it goes back to 0%. 2553 shrink_bytes = shrink_bytes / 100 * current_shrink_factor; 2554 2555 shrink_bytes = align_down(shrink_bytes, Metaspace::commit_alignment()); 2556 2557 assert(shrink_bytes <= max_shrink_bytes, 2558 "invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT, 2559 shrink_bytes, max_shrink_bytes); 2560 if (current_shrink_factor == 0) { 2561 _shrink_factor = 10; 2562 } else { 2563 _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100); 2564 } 2565 log_trace(gc, metaspace)(" shrinking: initThreshold: %.1fK maximum_desired_capacity: %.1fK", 2566 MetaspaceSize / (double) K, maximum_desired_capacity / (double) K); 2567 log_trace(gc, metaspace)(" shrink_bytes: %.1fK current_shrink_factor: %d new shrink factor: %d MinMetaspaceExpansion: %.1fK", 2568 shrink_bytes / (double) K, current_shrink_factor, _shrink_factor, MinMetaspaceExpansion / (double) K); 2569 } 2570 } 2571 2572 // Don't shrink unless it's significant 2573 if (shrink_bytes >= MinMetaspaceExpansion && 2574 ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) { 2575 size_t new_capacity_until_GC = MetaspaceGC::dec_capacity_until_GC(shrink_bytes); 2576 Metaspace::tracer()->report_gc_threshold(capacity_until_GC, 2577 new_capacity_until_GC, 2578 MetaspaceGCThresholdUpdater::ComputeNewSize); 2579 } 2580 } 2581 2582 // Metadebug methods 2583 2584 void Metadebug::init_allocation_fail_alot_count() { 2585 if (MetadataAllocationFailALot) { 2586 _allocation_fail_alot_count = 2587 1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0)); 2588 } 2589 } 2590 2591 #ifdef ASSERT 2592 bool Metadebug::test_metadata_failure() { 2593 if (MetadataAllocationFailALot && 2594 Threads::is_vm_complete()) { 2595 if (_allocation_fail_alot_count > 0) { 2596 _allocation_fail_alot_count--; 2597 } else { 2598 log_trace(gc, metaspace, freelist)("Metadata allocation failing for MetadataAllocationFailALot"); 2599 init_allocation_fail_alot_count(); 2600 return true; 2601 } 2602 } 2603 return false; 2604 } 2605 #endif 2606 2607 // ChunkManager methods 2608 size_t ChunkManager::free_chunks_total_words() { 2609 return _free_chunks_total; 2610 } 2611 2612 size_t ChunkManager::free_chunks_total_bytes() { 2613 return free_chunks_total_words() * BytesPerWord; 2614 } 2615 2616 // Update internal accounting after a chunk was added 2617 void ChunkManager::account_for_added_chunk(const Metachunk* c) { 2618 assert_lock_strong(SpaceManager::expand_lock()); 2619 _free_chunks_count ++; 2620 _free_chunks_total += c->word_size(); 2621 } 2622 2623 // Update internal accounting after a chunk was removed 2624 void ChunkManager::account_for_removed_chunk(const Metachunk* c) { 2625 assert_lock_strong(SpaceManager::expand_lock()); 2626 assert(_free_chunks_count >= 1, 2627 "ChunkManager::_free_chunks_count: about to go negative (" SIZE_FORMAT ").", _free_chunks_count); 2628 assert(_free_chunks_total >= c->word_size(), 2629 "ChunkManager::_free_chunks_total: about to go negative" 2630 "(now: " SIZE_FORMAT ", decrement value: " SIZE_FORMAT ").", _free_chunks_total, c->word_size()); 2631 _free_chunks_count --; 2632 _free_chunks_total -= c->word_size(); 2633 } 2634 2635 size_t ChunkManager::free_chunks_count() { 2636 #ifdef ASSERT 2637 if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) { 2638 MutexLockerEx cl(SpaceManager::expand_lock(), 2639 Mutex::_no_safepoint_check_flag); 2640 // This lock is only needed in debug because the verification 2641 // of the _free_chunks_totals walks the list of free chunks 2642 slow_locked_verify_free_chunks_count(); 2643 } 2644 #endif 2645 return _free_chunks_count; 2646 } 2647 2648 ChunkIndex ChunkManager::list_index(size_t size) { 2649 if (size_by_index(SpecializedIndex) == size) { 2650 return SpecializedIndex; 2651 } 2652 if (size_by_index(SmallIndex) == size) { 2653 return SmallIndex; 2654 } 2655 const size_t med_size = size_by_index(MediumIndex); 2656 if (med_size == size) { 2657 return MediumIndex; 2658 } 2659 2660 assert(size > med_size, "Not a humongous chunk"); 2661 return HumongousIndex; 2662 } 2663 2664 size_t ChunkManager::size_by_index(ChunkIndex index) const { 2665 index_bounds_check(index); 2666 assert(index != HumongousIndex, "Do not call for humongous chunks."); 2667 return _free_chunks[index].size(); 2668 } 2669 2670 void ChunkManager::locked_verify_free_chunks_total() { 2671 assert_lock_strong(SpaceManager::expand_lock()); 2672 assert(sum_free_chunks() == _free_chunks_total, 2673 "_free_chunks_total " SIZE_FORMAT " is not the" 2674 " same as sum " SIZE_FORMAT, _free_chunks_total, 2675 sum_free_chunks()); 2676 } 2677 2678 void ChunkManager::verify_free_chunks_total() { 2679 MutexLockerEx cl(SpaceManager::expand_lock(), 2680 Mutex::_no_safepoint_check_flag); 2681 locked_verify_free_chunks_total(); 2682 } 2683 2684 void ChunkManager::locked_verify_free_chunks_count() { 2685 assert_lock_strong(SpaceManager::expand_lock()); 2686 assert(sum_free_chunks_count() == _free_chunks_count, 2687 "_free_chunks_count " SIZE_FORMAT " is not the" 2688 " same as sum " SIZE_FORMAT, _free_chunks_count, 2689 sum_free_chunks_count()); 2690 } 2691 2692 void ChunkManager::verify_free_chunks_count() { 2693 #ifdef ASSERT 2694 MutexLockerEx cl(SpaceManager::expand_lock(), 2695 Mutex::_no_safepoint_check_flag); 2696 locked_verify_free_chunks_count(); 2697 #endif 2698 } 2699 2700 void ChunkManager::verify() { 2701 MutexLockerEx cl(SpaceManager::expand_lock(), 2702 Mutex::_no_safepoint_check_flag); 2703 locked_verify(); 2704 } 2705 2706 void ChunkManager::locked_verify() { 2707 locked_verify_free_chunks_count(); 2708 locked_verify_free_chunks_total(); 2709 for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) { 2710 ChunkList* list = free_chunks(i); 2711 if (list != NULL) { 2712 Metachunk* chunk = list->head(); 2713 while (chunk) { 2714 DEBUG_ONLY(do_verify_chunk(chunk);) 2715 assert(chunk->is_tagged_free(), "Chunk should be tagged as free."); 2716 chunk = chunk->next(); 2717 } 2718 } 2719 } 2720 } 2721 2722 void ChunkManager::locked_print_free_chunks(outputStream* st) { 2723 assert_lock_strong(SpaceManager::expand_lock()); 2724 st->print_cr("Free chunk total " SIZE_FORMAT " count " SIZE_FORMAT, 2725 _free_chunks_total, _free_chunks_count); 2726 } 2727 2728 void ChunkManager::locked_print_sum_free_chunks(outputStream* st) { 2729 assert_lock_strong(SpaceManager::expand_lock()); 2730 st->print_cr("Sum free chunk total " SIZE_FORMAT " count " SIZE_FORMAT, 2731 sum_free_chunks(), sum_free_chunks_count()); 2732 } 2733 2734 ChunkList* ChunkManager::free_chunks(ChunkIndex index) { 2735 assert(index == SpecializedIndex || index == SmallIndex || index == MediumIndex, 2736 "Bad index: %d", (int)index); 2737 2738 return &_free_chunks[index]; 2739 } 2740 2741 // These methods that sum the free chunk lists are used in printing 2742 // methods that are used in product builds. 2743 size_t ChunkManager::sum_free_chunks() { 2744 assert_lock_strong(SpaceManager::expand_lock()); 2745 size_t result = 0; 2746 for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) { 2747 ChunkList* list = free_chunks(i); 2748 2749 if (list == NULL) { 2750 continue; 2751 } 2752 2753 result = result + list->count() * list->size(); 2754 } 2755 result = result + humongous_dictionary()->total_size(); 2756 return result; 2757 } 2758 2759 size_t ChunkManager::sum_free_chunks_count() { 2760 assert_lock_strong(SpaceManager::expand_lock()); 2761 size_t count = 0; 2762 for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) { 2763 ChunkList* list = free_chunks(i); 2764 if (list == NULL) { 2765 continue; 2766 } 2767 count = count + list->count(); 2768 } 2769 count = count + humongous_dictionary()->total_free_blocks(); 2770 return count; 2771 } 2772 2773 ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) { 2774 ChunkIndex index = list_index(word_size); 2775 assert(index < HumongousIndex, "No humongous list"); 2776 return free_chunks(index); 2777 } 2778 2779 // Helper for chunk splitting: given a target chunk size and a larger free chunk, 2780 // split up the larger chunk into n smaller chunks, at least one of which should be 2781 // the target chunk of target chunk size. The smaller chunks, including the target 2782 // chunk, are returned to the freelist. The pointer to the target chunk is returned. 2783 // Note that this chunk is supposed to be removed from the freelist right away. 2784 Metachunk* ChunkManager::split_chunk(size_t target_chunk_word_size, Metachunk* larger_chunk) { 2785 assert(larger_chunk->word_size() > target_chunk_word_size, "Sanity"); 2786 2787 const ChunkIndex larger_chunk_index = larger_chunk->get_chunk_type(); 2788 const ChunkIndex target_chunk_index = get_chunk_type_by_size(target_chunk_word_size, is_class()); 2789 2790 MetaWord* const region_start = (MetaWord*)larger_chunk; 2791 const size_t region_word_len = larger_chunk->word_size(); 2792 MetaWord* const region_end = region_start + region_word_len; 2793 VirtualSpaceNode* const vsn = larger_chunk->container(); 2794 OccupancyMap* const ocmap = vsn->occupancy_map(); 2795 2796 // Any larger non-humongous chunk size is a multiple of any smaller chunk size. 2797 // Since non-humongous chunks are aligned to their chunk size, the larger chunk should start 2798 // at an address suitable to place the smaller target chunk. 2799 assert_is_aligned(region_start, target_chunk_word_size); 2800 2801 // Remove old chunk. 2802 free_chunks(larger_chunk_index)->remove_chunk(larger_chunk); 2803 larger_chunk->remove_sentinel(); 2804 2805 // Prevent access to the old chunk from here on. 2806 larger_chunk = NULL; 2807 // ... and wipe it. 2808 DEBUG_ONLY(memset(region_start, 0xfe, region_word_len * BytesPerWord)); 2809 2810 // In its place create first the target chunk... 2811 MetaWord* p = region_start; 2812 Metachunk* target_chunk = ::new (p) Metachunk(target_chunk_index, is_class(), target_chunk_word_size, vsn); 2813 assert(target_chunk == (Metachunk*)p, "Sanity"); 2814 target_chunk->set_origin(origin_split); 2815 2816 // Note: we do not need to mark its start in the occupancy map 2817 // because it coincides with the old chunk start. 2818 2819 // Mark chunk as free and return to the freelist. 2820 do_update_in_use_info_for_chunk(target_chunk, false); 2821 free_chunks(target_chunk_index)->return_chunk_at_head(target_chunk); 2822 2823 // This chunk should now be valid and can be verified. 2824 DEBUG_ONLY(do_verify_chunk(target_chunk)); 2825 2826 // In the remaining space create the remainder chunks. 2827 p += target_chunk->word_size(); 2828 assert(p < region_end, "Sanity"); 2829 2830 while (p < region_end) { 2831 2832 // Find the largest chunk size which fits the alignment requirements at address p. 2833 ChunkIndex this_chunk_index = prev_chunk_index(larger_chunk_index); 2834 size_t this_chunk_word_size = 0; 2835 for(;;) { 2836 this_chunk_word_size = get_size_for_nonhumongous_chunktype(this_chunk_index, is_class()); 2837 if (is_aligned(p, this_chunk_word_size * BytesPerWord)) { 2838 break; 2839 } else { 2840 this_chunk_index = prev_chunk_index(this_chunk_index); 2841 assert(this_chunk_index >= target_chunk_index, "Sanity"); 2842 } 2843 } 2844 2845 assert(this_chunk_word_size >= target_chunk_word_size, "Sanity"); 2846 assert(is_aligned(p, this_chunk_word_size * BytesPerWord), "Sanity"); 2847 assert(p + this_chunk_word_size <= region_end, "Sanity"); 2848 2849 // Create splitting chunk. 2850 Metachunk* this_chunk = ::new (p) Metachunk(this_chunk_index, is_class(), this_chunk_word_size, vsn); 2851 assert(this_chunk == (Metachunk*)p, "Sanity"); 2852 this_chunk->set_origin(origin_split); 2853 ocmap->set_chunk_starts_at_address(p, true); 2854 do_update_in_use_info_for_chunk(this_chunk, false); 2855 2856 // This chunk should be valid and can be verified. 2857 DEBUG_ONLY(do_verify_chunk(this_chunk)); 2858 2859 // Return this chunk to freelist and correct counter. 2860 free_chunks(this_chunk_index)->return_chunk_at_head(this_chunk); 2861 _free_chunks_count ++; 2862 2863 log_trace(gc, metaspace, freelist)("Created chunk at " PTR_FORMAT ", word size " 2864 SIZE_FORMAT_HEX " (%s), in split region [" PTR_FORMAT "..." PTR_FORMAT ").", 2865 p2i(this_chunk), this_chunk->word_size(), chunk_size_name(this_chunk_index), 2866 p2i(region_start), p2i(region_end)); 2867 2868 p += this_chunk_word_size; 2869 2870 } 2871 2872 return target_chunk; 2873 } 2874 2875 Metachunk* ChunkManager::free_chunks_get(size_t word_size) { 2876 assert_lock_strong(SpaceManager::expand_lock()); 2877 2878 slow_locked_verify(); 2879 2880 Metachunk* chunk = NULL; 2881 bool we_did_split_a_chunk = false; 2882 2883 if (list_index(word_size) != HumongousIndex) { 2884 2885 ChunkList* free_list = find_free_chunks_list(word_size); 2886 assert(free_list != NULL, "Sanity check"); 2887 2888 chunk = free_list->head(); 2889 2890 if (chunk == NULL) { 2891 // Split large chunks into smaller chunks if there are no smaller chunks, just large chunks. 2892 // This is the counterpart of the coalescing-upon-chunk-return. 2893 2894 ChunkIndex target_chunk_index = get_chunk_type_by_size(word_size, is_class()); 2895 2896 // Is there a larger chunk we could split? 2897 Metachunk* larger_chunk = NULL; 2898 ChunkIndex larger_chunk_index = next_chunk_index(target_chunk_index); 2899 while (larger_chunk == NULL && larger_chunk_index < NumberOfFreeLists) { 2900 larger_chunk = free_chunks(larger_chunk_index)->head(); 2901 if (larger_chunk == NULL) { 2902 larger_chunk_index = next_chunk_index(larger_chunk_index); 2903 } 2904 } 2905 2906 if (larger_chunk != NULL) { 2907 assert(larger_chunk->word_size() > word_size, "Sanity"); 2908 assert(larger_chunk->get_chunk_type() == larger_chunk_index, "Sanity"); 2909 2910 // We found a larger chunk. Lets split it up: 2911 // - remove old chunk 2912 // - in its place, create new smaller chunks, with at least one chunk 2913 // being of target size, the others sized as large as possible. This 2914 // is to make sure the resulting chunks are "as coalesced as possible" 2915 // (similar to VirtualSpaceNode::retire()). 2916 // Note: during this operation both ChunkManager and VirtualSpaceNode 2917 // are temporarily invalid, so be careful with asserts. 2918 2919 log_trace(gc, metaspace, freelist)("%s: splitting chunk " PTR_FORMAT 2920 ", word size " SIZE_FORMAT_HEX " (%s), to get a chunk of word size " SIZE_FORMAT_HEX " (%s)...", 2921 (is_class() ? "class space" : "metaspace"), p2i(larger_chunk), larger_chunk->word_size(), 2922 chunk_size_name(larger_chunk_index), word_size, chunk_size_name(target_chunk_index)); 2923 2924 chunk = split_chunk(word_size, larger_chunk); 2925 2926 // This should have worked. 2927 assert(chunk != NULL, "Sanity"); 2928 assert(chunk->word_size() == word_size, "Sanity"); 2929 assert(chunk->is_tagged_free(), "Sanity"); 2930 2931 we_did_split_a_chunk = true; 2932 2933 } 2934 } 2935 2936 if (chunk == NULL) { 2937 return NULL; 2938 } 2939 2940 // Remove the chunk as the head of the list. 2941 free_list->remove_chunk(chunk); 2942 2943 log_trace(gc, metaspace, freelist)("ChunkManager::free_chunks_get: free_list: " PTR_FORMAT " chunks left: " SSIZE_FORMAT ".", 2944 p2i(free_list), free_list->count()); 2945 2946 } else { 2947 chunk = humongous_dictionary()->get_chunk(word_size); 2948 2949 if (chunk == NULL) { 2950 return NULL; 2951 } 2952 2953 log_debug(gc, metaspace, alloc)("Free list allocate humongous chunk size " SIZE_FORMAT " for requested size " SIZE_FORMAT " waste " SIZE_FORMAT, 2954 chunk->word_size(), word_size, chunk->word_size() - word_size); 2955 } 2956 2957 // Chunk has been removed from the chunk manager; update counters. 2958 account_for_removed_chunk(chunk); 2959 do_update_in_use_info_for_chunk(chunk, true); 2960 chunk->container()->inc_container_count(); 2961 chunk->inc_use_count(); 2962 2963 // Remove it from the links to this freelist 2964 chunk->set_next(NULL); 2965 chunk->set_prev(NULL); 2966 2967 // Run some verifications (some more if we did a chunk split) 2968 #ifdef ASSERT 2969 locked_verify(); 2970 VirtualSpaceNode* const vsn = chunk->container(); 2971 vsn->verify(); 2972 if (we_did_split_a_chunk) { 2973 vsn->verify_free_chunks_are_ideally_merged(); 2974 } 2975 #endif 2976 2977 return chunk; 2978 } 2979 2980 Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) { 2981 assert_lock_strong(SpaceManager::expand_lock()); 2982 slow_locked_verify(); 2983 2984 // Take from the beginning of the list 2985 Metachunk* chunk = free_chunks_get(word_size); 2986 if (chunk == NULL) { 2987 return NULL; 2988 } 2989 2990 assert((word_size <= chunk->word_size()) || 2991 (list_index(chunk->word_size()) == HumongousIndex), 2992 "Non-humongous variable sized chunk"); 2993 LogTarget(Debug, gc, metaspace, freelist) lt; 2994 if (lt.is_enabled()) { 2995 size_t list_count; 2996 if (list_index(word_size) < HumongousIndex) { 2997 ChunkList* list = find_free_chunks_list(word_size); 2998 list_count = list->count(); 2999 } else { 3000 list_count = humongous_dictionary()->total_count(); 3001 } 3002 LogStream ls(lt); 3003 ls.print("ChunkManager::chunk_freelist_allocate: " PTR_FORMAT " chunk " PTR_FORMAT " size " SIZE_FORMAT " count " SIZE_FORMAT " ", 3004 p2i(this), p2i(chunk), chunk->word_size(), list_count); 3005 ResourceMark rm; 3006 locked_print_free_chunks(&ls); 3007 } 3008 3009 return chunk; 3010 } 3011 3012 void ChunkManager::return_single_chunk(ChunkIndex index, Metachunk* chunk) { 3013 assert_lock_strong(SpaceManager::expand_lock()); 3014 DEBUG_ONLY(do_verify_chunk(chunk);) 3015 assert(chunk->get_chunk_type() == index, "Chunk does not match expected index."); 3016 assert(chunk != NULL, "Expected chunk."); 3017 assert(chunk->container() != NULL, "Container should have been set."); 3018 assert(chunk->is_tagged_free() == false, "Chunk should be in use."); 3019 index_bounds_check(index); 3020 3021 // Note: mangle *before* returning the chunk to the freelist or dictionary. It does not 3022 // matter for the freelist (non-humongous chunks), but the humongous chunk dictionary 3023 // keeps tree node pointers in the chunk payload area which mangle will overwrite. 3024 DEBUG_ONLY(chunk->mangle(badMetaWordVal);) 3025 3026 if (index != HumongousIndex) { 3027 // Return non-humongous chunk to freelist. 3028 ChunkList* list = free_chunks(index); 3029 assert(list->size() == chunk->word_size(), "Wrong chunk type."); 3030 list->return_chunk_at_head(chunk); 3031 log_trace(gc, metaspace, freelist)("returned one %s chunk at " PTR_FORMAT " to freelist.", 3032 chunk_size_name(index), p2i(chunk)); 3033 } else { 3034 // Return humongous chunk to dictionary. 3035 assert(chunk->word_size() > free_chunks(MediumIndex)->size(), "Wrong chunk type."); 3036 assert(chunk->word_size() % free_chunks(SpecializedIndex)->size() == 0, 3037 "Humongous chunk has wrong alignment."); 3038 _humongous_dictionary.return_chunk(chunk); 3039 log_trace(gc, metaspace, freelist)("returned one %s chunk at " PTR_FORMAT " (word size " SIZE_FORMAT ") to freelist.", 3040 chunk_size_name(index), p2i(chunk), chunk->word_size()); 3041 } 3042 chunk->container()->dec_container_count(); 3043 do_update_in_use_info_for_chunk(chunk, false); 3044 3045 // Chunk has been added; update counters. 3046 account_for_added_chunk(chunk); 3047 3048 // Attempt coalesce returned chunks with its neighboring chunks: 3049 // if this chunk is small or special, attempt to coalesce to a medium chunk. 3050 if (index == SmallIndex || index == SpecializedIndex) { 3051 if (!attempt_to_coalesce_around_chunk(chunk, MediumIndex)) { 3052 // This did not work. But if this chunk is special, we still may form a small chunk? 3053 if (index == SpecializedIndex) { 3054 if (!attempt_to_coalesce_around_chunk(chunk, SmallIndex)) { 3055 // give up. 3056 } 3057 } 3058 } 3059 } 3060 3061 } 3062 3063 void ChunkManager::return_chunk_list(ChunkIndex index, Metachunk* chunks) { 3064 index_bounds_check(index); 3065 if (chunks == NULL) { 3066 return; 3067 } 3068 LogTarget(Trace, gc, metaspace, freelist) log; 3069 if (log.is_enabled()) { // tracing 3070 log.print("returning list of %s chunks...", chunk_size_name(index)); 3071 } 3072 unsigned num_chunks_returned = 0; 3073 size_t size_chunks_returned = 0; 3074 Metachunk* cur = chunks; 3075 while (cur != NULL) { 3076 // Capture the next link before it is changed 3077 // by the call to return_chunk_at_head(); 3078 Metachunk* next = cur->next(); 3079 if (log.is_enabled()) { // tracing 3080 num_chunks_returned ++; 3081 size_chunks_returned += cur->word_size(); 3082 } 3083 return_single_chunk(index, cur); 3084 cur = next; 3085 } 3086 if (log.is_enabled()) { // tracing 3087 log.print("returned %u %s chunks to freelist, total word size " SIZE_FORMAT ".", 3088 num_chunks_returned, chunk_size_name(index), size_chunks_returned); 3089 if (index != HumongousIndex) { 3090 log.print("updated freelist count: " SIZE_FORMAT ".", free_chunks(index)->size()); 3091 } else { 3092 log.print("updated dictionary count " SIZE_FORMAT ".", _humongous_dictionary.total_count()); 3093 } 3094 } 3095 } 3096 3097 void ChunkManager::print_on(outputStream* out) const { 3098 _humongous_dictionary.report_statistics(out); 3099 } 3100 3101 void ChunkManager::locked_get_statistics(ChunkManagerStatistics* stat) const { 3102 assert_lock_strong(SpaceManager::expand_lock()); 3103 for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) { 3104 stat->num_by_type[i] = num_free_chunks(i); 3105 stat->single_size_by_type[i] = size_by_index(i); 3106 stat->total_size_by_type[i] = size_free_chunks_in_bytes(i); 3107 } 3108 stat->num_humongous_chunks = num_free_chunks(HumongousIndex); 3109 stat->total_size_humongous_chunks = size_free_chunks_in_bytes(HumongousIndex); 3110 } 3111 3112 void ChunkManager::get_statistics(ChunkManagerStatistics* stat) const { 3113 MutexLockerEx cl(SpaceManager::expand_lock(), 3114 Mutex::_no_safepoint_check_flag); 3115 locked_get_statistics(stat); 3116 } 3117 3118 void ChunkManager::print_statistics(const ChunkManagerStatistics* stat, outputStream* out, size_t scale) { 3119 size_t total = 0; 3120 assert(scale == 1 || scale == K || scale == M || scale == G, "Invalid scale"); 3121 3122 const char* unit = scale_unit(scale); 3123 for (ChunkIndex i = ZeroIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) { 3124 out->print(" " SIZE_FORMAT " %s (" SIZE_FORMAT " bytes) chunks, total ", 3125 stat->num_by_type[i], chunk_size_name(i), 3126 stat->single_size_by_type[i]); 3127 if (scale == 1) { 3128 out->print_cr(SIZE_FORMAT " bytes", stat->total_size_by_type[i]); 3129 } else { 3130 out->print_cr("%.2f%s", (float)stat->total_size_by_type[i] / scale, unit); 3131 } 3132 3133 total += stat->total_size_by_type[i]; 3134 } 3135 3136 3137 total += stat->total_size_humongous_chunks; 3138 3139 if (scale == 1) { 3140 out->print_cr(" " SIZE_FORMAT " humongous chunks, total " SIZE_FORMAT " bytes", 3141 stat->num_humongous_chunks, stat->total_size_humongous_chunks); 3142 3143 out->print_cr(" total size: " SIZE_FORMAT " bytes.", total); 3144 } else { 3145 out->print_cr(" " SIZE_FORMAT " humongous chunks, total %.2f%s", 3146 stat->num_humongous_chunks, 3147 (float)stat->total_size_humongous_chunks / scale, unit); 3148 3149 out->print_cr(" total size: %.2f%s.", (float)total / scale, unit); 3150 } 3151 3152 } 3153 3154 void ChunkManager::print_all_chunkmanagers(outputStream* out, size_t scale) { 3155 assert(scale == 1 || scale == K || scale == M || scale == G, "Invalid scale"); 3156 3157 // Note: keep lock protection only to retrieving statistics; keep printing 3158 // out of lock protection 3159 ChunkManagerStatistics stat; 3160 out->print_cr("Chunkmanager (non-class):"); 3161 const ChunkManager* const non_class_cm = Metaspace::chunk_manager_metadata(); 3162 if (non_class_cm != NULL) { 3163 non_class_cm->get_statistics(&stat); 3164 ChunkManager::print_statistics(&stat, out, scale); 3165 } else { 3166 out->print_cr("unavailable."); 3167 } 3168 out->print_cr("Chunkmanager (class):"); 3169 const ChunkManager* const class_cm = Metaspace::chunk_manager_class(); 3170 if (class_cm != NULL) { 3171 class_cm->get_statistics(&stat); 3172 ChunkManager::print_statistics(&stat, out, scale); 3173 } else { 3174 out->print_cr("unavailable."); 3175 } 3176 } 3177 3178 // SpaceManager methods 3179 3180 size_t SpaceManager::adjust_initial_chunk_size(size_t requested, bool is_class_space) { 3181 size_t chunk_sizes[] = { 3182 specialized_chunk_size(is_class_space), 3183 small_chunk_size(is_class_space), 3184 medium_chunk_size(is_class_space) 3185 }; 3186 3187 // Adjust up to one of the fixed chunk sizes ... 3188 for (size_t i = 0; i < ARRAY_SIZE(chunk_sizes); i++) { 3189 if (requested <= chunk_sizes[i]) { 3190 return chunk_sizes[i]; 3191 } 3192 } 3193 3194 // ... or return the size as a humongous chunk. 3195 return requested; 3196 } 3197 3198 size_t SpaceManager::adjust_initial_chunk_size(size_t requested) const { 3199 return adjust_initial_chunk_size(requested, is_class()); 3200 } 3201 3202 size_t SpaceManager::get_initial_chunk_size(Metaspace::MetaspaceType type) const { 3203 size_t requested; 3204 3205 if (is_class()) { 3206 switch (type) { 3207 case Metaspace::BootMetaspaceType: requested = Metaspace::first_class_chunk_word_size(); break; 3208 case Metaspace::AnonymousMetaspaceType: requested = ClassSpecializedChunk; break; 3209 case Metaspace::ReflectionMetaspaceType: requested = ClassSpecializedChunk; break; 3210 default: requested = ClassSmallChunk; break; 3211 } 3212 } else { 3213 switch (type) { 3214 case Metaspace::BootMetaspaceType: requested = Metaspace::first_chunk_word_size(); break; 3215 case Metaspace::AnonymousMetaspaceType: requested = SpecializedChunk; break; 3216 case Metaspace::ReflectionMetaspaceType: requested = SpecializedChunk; break; 3217 default: requested = SmallChunk; break; 3218 } 3219 } 3220 3221 // Adjust to one of the fixed chunk sizes (unless humongous) 3222 const size_t adjusted = adjust_initial_chunk_size(requested); 3223 3224 assert(adjusted != 0, "Incorrect initial chunk size. Requested: " 3225 SIZE_FORMAT " adjusted: " SIZE_FORMAT, requested, adjusted); 3226 3227 return adjusted; 3228 } 3229 3230 size_t SpaceManager::sum_free_in_chunks_in_use() const { 3231 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 3232 size_t free = 0; 3233 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3234 Metachunk* chunk = chunks_in_use(i); 3235 while (chunk != NULL) { 3236 free += chunk->free_word_size(); 3237 chunk = chunk->next(); 3238 } 3239 } 3240 return free; 3241 } 3242 3243 size_t SpaceManager::sum_waste_in_chunks_in_use() const { 3244 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 3245 size_t result = 0; 3246 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3247 result += sum_waste_in_chunks_in_use(i); 3248 } 3249 3250 return result; 3251 } 3252 3253 size_t SpaceManager::sum_waste_in_chunks_in_use(ChunkIndex index) const { 3254 size_t result = 0; 3255 Metachunk* chunk = chunks_in_use(index); 3256 // Count the free space in all the chunk but not the 3257 // current chunk from which allocations are still being done. 3258 while (chunk != NULL) { 3259 if (chunk != current_chunk()) { 3260 result += chunk->free_word_size(); 3261 } 3262 chunk = chunk->next(); 3263 } 3264 return result; 3265 } 3266 3267 size_t SpaceManager::sum_capacity_in_chunks_in_use() const { 3268 // For CMS use "allocated_chunks_words()" which does not need the 3269 // Metaspace lock. For the other collectors sum over the 3270 // lists. Use both methods as a check that "allocated_chunks_words()" 3271 // is correct. That is, sum_capacity_in_chunks() is too expensive 3272 // to use in the product and allocated_chunks_words() should be used 3273 // but allow for checking that allocated_chunks_words() returns the same 3274 // value as sum_capacity_in_chunks_in_use() which is the definitive 3275 // answer. 3276 if (UseConcMarkSweepGC) { 3277 return allocated_chunks_words(); 3278 } else { 3279 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 3280 size_t sum = 0; 3281 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3282 Metachunk* chunk = chunks_in_use(i); 3283 while (chunk != NULL) { 3284 sum += chunk->word_size(); 3285 chunk = chunk->next(); 3286 } 3287 } 3288 return sum; 3289 } 3290 } 3291 3292 size_t SpaceManager::sum_count_in_chunks_in_use() { 3293 size_t count = 0; 3294 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3295 count = count + sum_count_in_chunks_in_use(i); 3296 } 3297 3298 return count; 3299 } 3300 3301 size_t SpaceManager::sum_count_in_chunks_in_use(ChunkIndex i) { 3302 size_t count = 0; 3303 Metachunk* chunk = chunks_in_use(i); 3304 while (chunk != NULL) { 3305 count++; 3306 chunk = chunk->next(); 3307 } 3308 return count; 3309 } 3310 3311 3312 size_t SpaceManager::sum_used_in_chunks_in_use() const { 3313 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 3314 size_t used = 0; 3315 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3316 Metachunk* chunk = chunks_in_use(i); 3317 while (chunk != NULL) { 3318 used += chunk->used_word_size(); 3319 chunk = chunk->next(); 3320 } 3321 } 3322 return used; 3323 } 3324 3325 void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const { 3326 3327 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3328 Metachunk* chunk = chunks_in_use(i); 3329 st->print("SpaceManager: %s " PTR_FORMAT, 3330 chunk_size_name(i), p2i(chunk)); 3331 if (chunk != NULL) { 3332 st->print_cr(" free " SIZE_FORMAT, 3333 chunk->free_word_size()); 3334 } else { 3335 st->cr(); 3336 } 3337 } 3338 3339 chunk_manager()->locked_print_free_chunks(st); 3340 chunk_manager()->locked_print_sum_free_chunks(st); 3341 } 3342 3343 size_t SpaceManager::calc_chunk_size(size_t word_size) { 3344 3345 // Decide between a small chunk and a medium chunk. Up to 3346 // _small_chunk_limit small chunks can be allocated. 3347 // After that a medium chunk is preferred. 3348 size_t chunk_word_size; 3349 3350 // Special case for anonymous metadata space. 3351 // Anonymous metadata space is usually small, with majority within 1K - 2K range and 3352 // rarely about 4K (64-bits JVM). 3353 // Instead of jumping to SmallChunk after initial chunk exhausted, keeping allocation 3354 // from SpecializeChunk up to _anon_metadata_specialize_chunk_limit (4) reduces space waste 3355 // from 60+% to around 30%. 3356 if (_space_type == Metaspace::AnonymousMetaspaceType && 3357 _mdtype == Metaspace::NonClassType && 3358 sum_count_in_chunks_in_use(SpecializedIndex) < _anon_metadata_specialize_chunk_limit && 3359 word_size + Metachunk::overhead() <= SpecializedChunk) { 3360 return SpecializedChunk; 3361 } 3362 3363 if (chunks_in_use(MediumIndex) == NULL && 3364 sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit) { 3365 chunk_word_size = (size_t) small_chunk_size(); 3366 if (word_size + Metachunk::overhead() > small_chunk_size()) { 3367 chunk_word_size = medium_chunk_size(); 3368 } 3369 } else { 3370 chunk_word_size = medium_chunk_size(); 3371 } 3372 3373 // Might still need a humongous chunk. Enforce 3374 // humongous allocations sizes to be aligned up to 3375 // the smallest chunk size. 3376 size_t if_humongous_sized_chunk = 3377 align_up(word_size + Metachunk::overhead(), 3378 smallest_chunk_size()); 3379 chunk_word_size = 3380 MAX2((size_t) chunk_word_size, if_humongous_sized_chunk); 3381 3382 assert(!SpaceManager::is_humongous(word_size) || 3383 chunk_word_size == if_humongous_sized_chunk, 3384 "Size calculation is wrong, word_size " SIZE_FORMAT 3385 " chunk_word_size " SIZE_FORMAT, 3386 word_size, chunk_word_size); 3387 Log(gc, metaspace, alloc) log; 3388 if (log.is_debug() && SpaceManager::is_humongous(word_size)) { 3389 log.debug("Metadata humongous allocation:"); 3390 log.debug(" word_size " PTR_FORMAT, word_size); 3391 log.debug(" chunk_word_size " PTR_FORMAT, chunk_word_size); 3392 log.debug(" chunk overhead " PTR_FORMAT, Metachunk::overhead()); 3393 } 3394 return chunk_word_size; 3395 } 3396 3397 void SpaceManager::track_metaspace_memory_usage() { 3398 if (is_init_completed()) { 3399 if (is_class()) { 3400 MemoryService::track_compressed_class_memory_usage(); 3401 } 3402 MemoryService::track_metaspace_memory_usage(); 3403 } 3404 } 3405 3406 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) { 3407 assert(vs_list()->current_virtual_space() != NULL, 3408 "Should have been set"); 3409 assert(current_chunk() == NULL || 3410 current_chunk()->allocate(word_size) == NULL, 3411 "Don't need to expand"); 3412 MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag); 3413 3414 if (log_is_enabled(Trace, gc, metaspace, freelist)) { 3415 size_t words_left = 0; 3416 size_t words_used = 0; 3417 if (current_chunk() != NULL) { 3418 words_left = current_chunk()->free_word_size(); 3419 words_used = current_chunk()->used_word_size(); 3420 } 3421 log_trace(gc, metaspace, freelist)("SpaceManager::grow_and_allocate for " SIZE_FORMAT " words " SIZE_FORMAT " words used " SIZE_FORMAT " words left", 3422 word_size, words_used, words_left); 3423 } 3424 3425 // Get another chunk 3426 size_t chunk_word_size = calc_chunk_size(word_size); 3427 Metachunk* next = get_new_chunk(chunk_word_size); 3428 3429 MetaWord* mem = NULL; 3430 3431 // If a chunk was available, add it to the in-use chunk list 3432 // and do an allocation from it. 3433 if (next != NULL) { 3434 // Add to this manager's list of chunks in use. 3435 add_chunk(next, false); 3436 mem = next->allocate(word_size); 3437 } 3438 3439 // Track metaspace memory usage statistic. 3440 track_metaspace_memory_usage(); 3441 3442 return mem; 3443 } 3444 3445 void SpaceManager::print_on(outputStream* st) const { 3446 3447 for (ChunkIndex i = ZeroIndex; 3448 i < NumberOfInUseLists ; 3449 i = next_chunk_index(i) ) { 3450 st->print_cr(" chunks_in_use " PTR_FORMAT " chunk size " SIZE_FORMAT, 3451 p2i(chunks_in_use(i)), 3452 chunks_in_use(i) == NULL ? 0 : chunks_in_use(i)->word_size()); 3453 } 3454 st->print_cr(" waste: Small " SIZE_FORMAT " Medium " SIZE_FORMAT 3455 " Humongous " SIZE_FORMAT, 3456 sum_waste_in_chunks_in_use(SmallIndex), 3457 sum_waste_in_chunks_in_use(MediumIndex), 3458 sum_waste_in_chunks_in_use(HumongousIndex)); 3459 // block free lists 3460 if (block_freelists() != NULL) { 3461 st->print_cr("total in block free lists " SIZE_FORMAT, 3462 block_freelists()->total_size()); 3463 } 3464 } 3465 3466 SpaceManager::SpaceManager(Metaspace::MetadataType mdtype, 3467 Metaspace::MetaspaceType space_type, 3468 Mutex* lock) : 3469 _mdtype(mdtype), 3470 _space_type(space_type), 3471 _allocated_blocks_words(0), 3472 _allocated_chunks_words(0), 3473 _allocated_chunks_count(0), 3474 _block_freelists(NULL), 3475 _lock(lock) 3476 { 3477 initialize(); 3478 } 3479 3480 void SpaceManager::inc_size_metrics(size_t words) { 3481 assert_lock_strong(SpaceManager::expand_lock()); 3482 // Total of allocated Metachunks and allocated Metachunks count 3483 // for each SpaceManager 3484 _allocated_chunks_words = _allocated_chunks_words + words; 3485 _allocated_chunks_count++; 3486 // Global total of capacity in allocated Metachunks 3487 MetaspaceAux::inc_capacity(mdtype(), words); 3488 // Global total of allocated Metablocks. 3489 // used_words_slow() includes the overhead in each 3490 // Metachunk so include it in the used when the 3491 // Metachunk is first added (so only added once per 3492 // Metachunk). 3493 MetaspaceAux::inc_used(mdtype(), Metachunk::overhead()); 3494 } 3495 3496 void SpaceManager::inc_used_metrics(size_t words) { 3497 // Add to the per SpaceManager total 3498 Atomic::add(words, &_allocated_blocks_words); 3499 // Add to the global total 3500 MetaspaceAux::inc_used(mdtype(), words); 3501 } 3502 3503 void SpaceManager::dec_total_from_size_metrics() { 3504 MetaspaceAux::dec_capacity(mdtype(), allocated_chunks_words()); 3505 MetaspaceAux::dec_used(mdtype(), allocated_blocks_words()); 3506 // Also deduct the overhead per Metachunk 3507 MetaspaceAux::dec_used(mdtype(), allocated_chunks_count() * Metachunk::overhead()); 3508 } 3509 3510 void SpaceManager::initialize() { 3511 Metadebug::init_allocation_fail_alot_count(); 3512 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3513 _chunks_in_use[i] = NULL; 3514 } 3515 _current_chunk = NULL; 3516 log_trace(gc, metaspace, freelist)("SpaceManager(): " PTR_FORMAT, p2i(this)); 3517 } 3518 3519 SpaceManager::~SpaceManager() { 3520 // This call this->_lock which can't be done while holding expand_lock() 3521 assert(sum_capacity_in_chunks_in_use() == allocated_chunks_words(), 3522 "sum_capacity_in_chunks_in_use() " SIZE_FORMAT 3523 " allocated_chunks_words() " SIZE_FORMAT, 3524 sum_capacity_in_chunks_in_use(), allocated_chunks_words()); 3525 3526 MutexLockerEx fcl(SpaceManager::expand_lock(), 3527 Mutex::_no_safepoint_check_flag); 3528 3529 assert(sum_count_in_chunks_in_use() == allocated_chunks_count(), 3530 "sum_count_in_chunks_in_use() " SIZE_FORMAT 3531 " allocated_chunks_count() " SIZE_FORMAT, 3532 sum_count_in_chunks_in_use(), allocated_chunks_count()); 3533 3534 chunk_manager()->slow_locked_verify(); 3535 3536 dec_total_from_size_metrics(); 3537 3538 Log(gc, metaspace, freelist) log; 3539 if (log.is_trace()) { 3540 log.trace("~SpaceManager(): " PTR_FORMAT, p2i(this)); 3541 ResourceMark rm; 3542 LogStream ls(log.trace()); 3543 locked_print_chunks_in_use_on(&ls); 3544 if (block_freelists() != NULL) { 3545 block_freelists()->print_on(&ls); 3546 } 3547 } 3548 3549 // Add all the chunks in use by this space manager 3550 // to the global list of free chunks. 3551 3552 // Follow each list of chunks-in-use and add them to the 3553 // free lists. Each list is NULL terminated. 3554 3555 for (ChunkIndex i = ZeroIndex; i <= HumongousIndex; i = next_chunk_index(i)) { 3556 Metachunk* chunks = chunks_in_use(i); 3557 chunk_manager()->return_chunk_list(i, chunks); 3558 set_chunks_in_use(i, NULL); 3559 } 3560 3561 chunk_manager()->slow_locked_verify(); 3562 3563 if (_block_freelists != NULL) { 3564 delete _block_freelists; 3565 } 3566 } 3567 3568 void SpaceManager::deallocate(MetaWord* p, size_t word_size) { 3569 assert_lock_strong(_lock); 3570 // Allocations and deallocations are in raw_word_size 3571 size_t raw_word_size = get_allocation_word_size(word_size); 3572 // Lazily create a block_freelist 3573 if (block_freelists() == NULL) { 3574 _block_freelists = new BlockFreelist(); 3575 } 3576 block_freelists()->return_block(p, raw_word_size); 3577 } 3578 3579 // Adds a chunk to the list of chunks in use. 3580 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) { 3581 3582 assert(new_chunk != NULL, "Should not be NULL"); 3583 assert(new_chunk->next() == NULL, "Should not be on a list"); 3584 3585 new_chunk->reset_empty(); 3586 3587 // Find the correct list and and set the current 3588 // chunk for that list. 3589 ChunkIndex index = chunk_manager()->list_index(new_chunk->word_size()); 3590 3591 if (index != HumongousIndex) { 3592 retire_current_chunk(); 3593 set_current_chunk(new_chunk); 3594 new_chunk->set_next(chunks_in_use(index)); 3595 set_chunks_in_use(index, new_chunk); 3596 } else { 3597 // For null class loader data and DumpSharedSpaces, the first chunk isn't 3598 // small, so small will be null. Link this first chunk as the current 3599 // chunk. 3600 if (make_current) { 3601 // Set as the current chunk but otherwise treat as a humongous chunk. 3602 set_current_chunk(new_chunk); 3603 } 3604 // Link at head. The _current_chunk only points to a humongous chunk for 3605 // the null class loader metaspace (class and data virtual space managers) 3606 // any humongous chunks so will not point to the tail 3607 // of the humongous chunks list. 3608 new_chunk->set_next(chunks_in_use(HumongousIndex)); 3609 set_chunks_in_use(HumongousIndex, new_chunk); 3610 3611 assert(new_chunk->word_size() > medium_chunk_size(), "List inconsistency"); 3612 } 3613 3614 // Add to the running sum of capacity 3615 inc_size_metrics(new_chunk->word_size()); 3616 3617 assert(new_chunk->is_empty(), "Not ready for reuse"); 3618 Log(gc, metaspace, freelist) log; 3619 if (log.is_trace()) { 3620 log.trace("SpaceManager::add_chunk: " SIZE_FORMAT ") ", sum_count_in_chunks_in_use()); 3621 ResourceMark rm; 3622 LogStream ls(log.trace()); 3623 new_chunk->print_on(&ls); 3624 chunk_manager()->locked_print_free_chunks(&ls); 3625 } 3626 } 3627 3628 void SpaceManager::retire_current_chunk() { 3629 if (current_chunk() != NULL) { 3630 size_t remaining_words = current_chunk()->free_word_size(); 3631 if (remaining_words >= BlockFreelist::min_dictionary_size()) { 3632 MetaWord* ptr = current_chunk()->allocate(remaining_words); 3633 deallocate(ptr, remaining_words); 3634 inc_used_metrics(remaining_words); 3635 } 3636 } 3637 } 3638 3639 Metachunk* SpaceManager::get_new_chunk(size_t chunk_word_size) { 3640 // Get a chunk from the chunk freelist 3641 Metachunk* next = chunk_manager()->chunk_freelist_allocate(chunk_word_size); 3642 3643 if (next == NULL) { 3644 next = vs_list()->get_new_chunk(chunk_word_size, 3645 medium_chunk_bunch()); 3646 } 3647 3648 Log(gc, metaspace, alloc) log; 3649 if (log.is_debug() && next != NULL && 3650 SpaceManager::is_humongous(next->word_size())) { 3651 log.debug(" new humongous chunk word size " PTR_FORMAT, next->word_size()); 3652 } 3653 3654 return next; 3655 } 3656 3657 MetaWord* SpaceManager::allocate(size_t word_size) { 3658 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag); 3659 size_t raw_word_size = get_allocation_word_size(word_size); 3660 BlockFreelist* fl = block_freelists(); 3661 MetaWord* p = NULL; 3662 // Allocation from the dictionary is expensive in the sense that 3663 // the dictionary has to be searched for a size. Don't allocate 3664 // from the dictionary until it starts to get fat. Is this 3665 // a reasonable policy? Maybe an skinny dictionary is fast enough 3666 // for allocations. Do some profiling. JJJ 3667 if (fl != NULL && fl->total_size() > allocation_from_dictionary_limit) { 3668 p = fl->get_block(raw_word_size); 3669 } 3670 if (p == NULL) { 3671 p = allocate_work(raw_word_size); 3672 } 3673 3674 return p; 3675 } 3676 3677 // Returns the address of spaced allocated for "word_size". 3678 // This methods does not know about blocks (Metablocks) 3679 MetaWord* SpaceManager::allocate_work(size_t word_size) { 3680 assert_lock_strong(_lock); 3681 #ifdef ASSERT 3682 if (Metadebug::test_metadata_failure()) { 3683 return NULL; 3684 } 3685 #endif 3686 // Is there space in the current chunk? 3687 MetaWord* result = NULL; 3688 3689 if (current_chunk() != NULL) { 3690 result = current_chunk()->allocate(word_size); 3691 } 3692 3693 if (result == NULL) { 3694 result = grow_and_allocate(word_size); 3695 } 3696 3697 if (result != NULL) { 3698 inc_used_metrics(word_size); 3699 assert(result != (MetaWord*) chunks_in_use(MediumIndex), 3700 "Head of the list is being allocated"); 3701 } 3702 3703 return result; 3704 } 3705 3706 void SpaceManager::verify() { 3707 // If there are blocks in the dictionary, then 3708 // verification of chunks does not work since 3709 // being in the dictionary alters a chunk. 3710 if (block_freelists() != NULL && block_freelists()->total_size() == 0) { 3711 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) { 3712 Metachunk* curr = chunks_in_use(i); 3713 while (curr != NULL) { 3714 DEBUG_ONLY(do_verify_chunk(curr);) 3715 assert(curr->is_tagged_free() == false, "Chunk should be tagged as in use."); 3716 curr = curr->next(); 3717 } 3718 } 3719 } 3720 } 3721 3722 void SpaceManager::verify_chunk_size(Metachunk* chunk) { 3723 assert(is_humongous(chunk->word_size()) || 3724 chunk->word_size() == medium_chunk_size() || 3725 chunk->word_size() == small_chunk_size() || 3726 chunk->word_size() == specialized_chunk_size(), 3727 "Chunk size is wrong"); 3728 return; 3729 } 3730 3731 #ifdef ASSERT 3732 void SpaceManager::verify_allocated_blocks_words() { 3733 // Verification is only guaranteed at a safepoint. 3734 assert(SafepointSynchronize::is_at_safepoint() || !Universe::is_fully_initialized(), 3735 "Verification can fail if the applications is running"); 3736 assert(allocated_blocks_words() == sum_used_in_chunks_in_use(), 3737 "allocation total is not consistent " SIZE_FORMAT 3738 " vs " SIZE_FORMAT, 3739 allocated_blocks_words(), sum_used_in_chunks_in_use()); 3740 } 3741 3742 #endif 3743 3744 void SpaceManager::dump(outputStream* const out) const { 3745 size_t curr_total = 0; 3746 size_t waste = 0; 3747 uint i = 0; 3748 size_t used = 0; 3749 size_t capacity = 0; 3750 3751 // Add up statistics for all chunks in this SpaceManager. 3752 for (ChunkIndex index = ZeroIndex; 3753 index < NumberOfInUseLists; 3754 index = next_chunk_index(index)) { 3755 for (Metachunk* curr = chunks_in_use(index); 3756 curr != NULL; 3757 curr = curr->next()) { 3758 out->print("%d) ", i++); 3759 curr->print_on(out); 3760 curr_total += curr->word_size(); 3761 used += curr->used_word_size(); 3762 capacity += curr->word_size(); 3763 waste += curr->free_word_size() + curr->overhead();; 3764 } 3765 } 3766 3767 if (log_is_enabled(Trace, gc, metaspace, freelist)) { 3768 if (block_freelists() != NULL) block_freelists()->print_on(out); 3769 } 3770 3771 size_t free = current_chunk() == NULL ? 0 : current_chunk()->free_word_size(); 3772 // Free space isn't wasted. 3773 waste -= free; 3774 3775 out->print_cr("total of all chunks " SIZE_FORMAT " used " SIZE_FORMAT 3776 " free " SIZE_FORMAT " capacity " SIZE_FORMAT 3777 " waste " SIZE_FORMAT, curr_total, used, free, capacity, waste); 3778 } 3779 3780 // MetaspaceAux 3781 3782 3783 size_t MetaspaceAux::_capacity_words[] = {0, 0}; 3784 volatile size_t MetaspaceAux::_used_words[] = {0, 0}; 3785 3786 size_t MetaspaceAux::free_bytes(Metaspace::MetadataType mdtype) { 3787 VirtualSpaceList* list = Metaspace::get_space_list(mdtype); 3788 return list == NULL ? 0 : list->free_bytes(); 3789 } 3790 3791 size_t MetaspaceAux::free_bytes() { 3792 return free_bytes(Metaspace::ClassType) + free_bytes(Metaspace::NonClassType); 3793 } 3794 3795 void MetaspaceAux::dec_capacity(Metaspace::MetadataType mdtype, size_t words) { 3796 assert_lock_strong(SpaceManager::expand_lock()); 3797 assert(words <= capacity_words(mdtype), 3798 "About to decrement below 0: words " SIZE_FORMAT 3799 " is greater than _capacity_words[%u] " SIZE_FORMAT, 3800 words, mdtype, capacity_words(mdtype)); 3801 _capacity_words[mdtype] -= words; 3802 } 3803 3804 void MetaspaceAux::inc_capacity(Metaspace::MetadataType mdtype, size_t words) { 3805 assert_lock_strong(SpaceManager::expand_lock()); 3806 // Needs to be atomic 3807 _capacity_words[mdtype] += words; 3808 } 3809 3810 void MetaspaceAux::dec_used(Metaspace::MetadataType mdtype, size_t words) { 3811 assert(words <= used_words(mdtype), 3812 "About to decrement below 0: words " SIZE_FORMAT 3813 " is greater than _used_words[%u] " SIZE_FORMAT, 3814 words, mdtype, used_words(mdtype)); 3815 // For CMS deallocation of the Metaspaces occurs during the 3816 // sweep which is a concurrent phase. Protection by the expand_lock() 3817 // is not enough since allocation is on a per Metaspace basis 3818 // and protected by the Metaspace lock. 3819 Atomic::sub(words, &_used_words[mdtype]); 3820 } 3821 3822 void MetaspaceAux::inc_used(Metaspace::MetadataType mdtype, size_t words) { 3823 // _used_words tracks allocations for 3824 // each piece of metadata. Those allocations are 3825 // generally done concurrently by different application 3826 // threads so must be done atomically. 3827 Atomic::add(words, &_used_words[mdtype]); 3828 } 3829 3830 size_t MetaspaceAux::used_bytes_slow(Metaspace::MetadataType mdtype) { 3831 size_t used = 0; 3832 ClassLoaderDataGraphMetaspaceIterator iter; 3833 while (iter.repeat()) { 3834 Metaspace* msp = iter.get_next(); 3835 // Sum allocated_blocks_words for each metaspace 3836 if (msp != NULL) { 3837 used += msp->used_words_slow(mdtype); 3838 } 3839 } 3840 return used * BytesPerWord; 3841 } 3842 3843 size_t MetaspaceAux::free_bytes_slow(Metaspace::MetadataType mdtype) { 3844 size_t free = 0; 3845 ClassLoaderDataGraphMetaspaceIterator iter; 3846 while (iter.repeat()) { 3847 Metaspace* msp = iter.get_next(); 3848 if (msp != NULL) { 3849 free += msp->free_words_slow(mdtype); 3850 } 3851 } 3852 return free * BytesPerWord; 3853 } 3854 3855 size_t MetaspaceAux::capacity_bytes_slow(Metaspace::MetadataType mdtype) { 3856 if ((mdtype == Metaspace::ClassType) && !Metaspace::using_class_space()) { 3857 return 0; 3858 } 3859 // Don't count the space in the freelists. That space will be 3860 // added to the capacity calculation as needed. 3861 size_t capacity = 0; 3862 ClassLoaderDataGraphMetaspaceIterator iter; 3863 while (iter.repeat()) { 3864 Metaspace* msp = iter.get_next(); 3865 if (msp != NULL) { 3866 capacity += msp->capacity_words_slow(mdtype); 3867 } 3868 } 3869 return capacity * BytesPerWord; 3870 } 3871 3872 size_t MetaspaceAux::capacity_bytes_slow() { 3873 #ifdef PRODUCT 3874 // Use capacity_bytes() in PRODUCT instead of this function. 3875 guarantee(false, "Should not call capacity_bytes_slow() in the PRODUCT"); 3876 #endif 3877 size_t class_capacity = capacity_bytes_slow(Metaspace::ClassType); 3878 size_t non_class_capacity = capacity_bytes_slow(Metaspace::NonClassType); 3879 assert(capacity_bytes() == class_capacity + non_class_capacity, 3880 "bad accounting: capacity_bytes() " SIZE_FORMAT 3881 " class_capacity + non_class_capacity " SIZE_FORMAT 3882 " class_capacity " SIZE_FORMAT " non_class_capacity " SIZE_FORMAT, 3883 capacity_bytes(), class_capacity + non_class_capacity, 3884 class_capacity, non_class_capacity); 3885 3886 return class_capacity + non_class_capacity; 3887 } 3888 3889 size_t MetaspaceAux::reserved_bytes(Metaspace::MetadataType mdtype) { 3890 VirtualSpaceList* list = Metaspace::get_space_list(mdtype); 3891 return list == NULL ? 0 : list->reserved_bytes(); 3892 } 3893 3894 size_t MetaspaceAux::committed_bytes(Metaspace::MetadataType mdtype) { 3895 VirtualSpaceList* list = Metaspace::get_space_list(mdtype); 3896 return list == NULL ? 0 : list->committed_bytes(); 3897 } 3898 3899 size_t MetaspaceAux::min_chunk_size_words() { return Metaspace::first_chunk_word_size(); } 3900 3901 size_t MetaspaceAux::free_chunks_total_words(Metaspace::MetadataType mdtype) { 3902 ChunkManager* chunk_manager = Metaspace::get_chunk_manager(mdtype); 3903 if (chunk_manager == NULL) { 3904 return 0; 3905 } 3906 chunk_manager->slow_verify(); 3907 return chunk_manager->free_chunks_total_words(); 3908 } 3909 3910 size_t MetaspaceAux::free_chunks_total_bytes(Metaspace::MetadataType mdtype) { 3911 return free_chunks_total_words(mdtype) * BytesPerWord; 3912 } 3913 3914 size_t MetaspaceAux::free_chunks_total_words() { 3915 return free_chunks_total_words(Metaspace::ClassType) + 3916 free_chunks_total_words(Metaspace::NonClassType); 3917 } 3918 3919 size_t MetaspaceAux::free_chunks_total_bytes() { 3920 return free_chunks_total_words() * BytesPerWord; 3921 } 3922 3923 bool MetaspaceAux::has_chunk_free_list(Metaspace::MetadataType mdtype) { 3924 return Metaspace::get_chunk_manager(mdtype) != NULL; 3925 } 3926 3927 MetaspaceChunkFreeListSummary MetaspaceAux::chunk_free_list_summary(Metaspace::MetadataType mdtype) { 3928 if (!has_chunk_free_list(mdtype)) { 3929 return MetaspaceChunkFreeListSummary(); 3930 } 3931 3932 const ChunkManager* cm = Metaspace::get_chunk_manager(mdtype); 3933 return cm->chunk_free_list_summary(); 3934 } 3935 3936 void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) { 3937 log_info(gc, metaspace)("Metaspace: " SIZE_FORMAT "K->" SIZE_FORMAT "K(" SIZE_FORMAT "K)", 3938 prev_metadata_used/K, used_bytes()/K, reserved_bytes()/K); 3939 } 3940 3941 void MetaspaceAux::print_on(outputStream* out) { 3942 Metaspace::MetadataType nct = Metaspace::NonClassType; 3943 3944 out->print_cr(" Metaspace " 3945 "used " SIZE_FORMAT "K, " 3946 "capacity " SIZE_FORMAT "K, " 3947 "committed " SIZE_FORMAT "K, " 3948 "reserved " SIZE_FORMAT "K", 3949 used_bytes()/K, 3950 capacity_bytes()/K, 3951 committed_bytes()/K, 3952 reserved_bytes()/K); 3953 3954 if (Metaspace::using_class_space()) { 3955 Metaspace::MetadataType ct = Metaspace::ClassType; 3956 out->print_cr(" class space " 3957 "used " SIZE_FORMAT "K, " 3958 "capacity " SIZE_FORMAT "K, " 3959 "committed " SIZE_FORMAT "K, " 3960 "reserved " SIZE_FORMAT "K", 3961 used_bytes(ct)/K, 3962 capacity_bytes(ct)/K, 3963 committed_bytes(ct)/K, 3964 reserved_bytes(ct)/K); 3965 } 3966 } 3967 3968 // Print information for class space and data space separately. 3969 // This is almost the same as above. 3970 void MetaspaceAux::print_on(outputStream* out, Metaspace::MetadataType mdtype) { 3971 size_t free_chunks_capacity_bytes = free_chunks_total_bytes(mdtype); 3972 size_t capacity_bytes = capacity_bytes_slow(mdtype); 3973 size_t used_bytes = used_bytes_slow(mdtype); 3974 size_t free_bytes = free_bytes_slow(mdtype); 3975 size_t used_and_free = used_bytes + free_bytes + 3976 free_chunks_capacity_bytes; 3977 out->print_cr(" Chunk accounting: (used in chunks " SIZE_FORMAT 3978 "K + unused in chunks " SIZE_FORMAT "K + " 3979 " capacity in free chunks " SIZE_FORMAT "K) = " SIZE_FORMAT 3980 "K capacity in allocated chunks " SIZE_FORMAT "K", 3981 used_bytes / K, 3982 free_bytes / K, 3983 free_chunks_capacity_bytes / K, 3984 used_and_free / K, 3985 capacity_bytes / K); 3986 // Accounting can only be correct if we got the values during a safepoint 3987 assert(!SafepointSynchronize::is_at_safepoint() || used_and_free == capacity_bytes, "Accounting is wrong"); 3988 } 3989 3990 // Print total fragmentation for class metaspaces 3991 void MetaspaceAux::print_class_waste(outputStream* out) { 3992 assert(Metaspace::using_class_space(), "class metaspace not used"); 3993 size_t cls_specialized_waste = 0, cls_small_waste = 0, cls_medium_waste = 0; 3994 size_t cls_specialized_count = 0, cls_small_count = 0, cls_medium_count = 0, cls_humongous_count = 0; 3995 ClassLoaderDataGraphMetaspaceIterator iter; 3996 while (iter.repeat()) { 3997 Metaspace* msp = iter.get_next(); 3998 if (msp != NULL) { 3999 cls_specialized_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SpecializedIndex); 4000 cls_specialized_count += msp->class_vsm()->sum_count_in_chunks_in_use(SpecializedIndex); 4001 cls_small_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SmallIndex); 4002 cls_small_count += msp->class_vsm()->sum_count_in_chunks_in_use(SmallIndex); 4003 cls_medium_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(MediumIndex); 4004 cls_medium_count += msp->class_vsm()->sum_count_in_chunks_in_use(MediumIndex); 4005 cls_humongous_count += msp->class_vsm()->sum_count_in_chunks_in_use(HumongousIndex); 4006 } 4007 } 4008 out->print_cr(" class: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", " 4009 SIZE_FORMAT " small(s) " SIZE_FORMAT ", " 4010 SIZE_FORMAT " medium(s) " SIZE_FORMAT ", " 4011 "large count " SIZE_FORMAT, 4012 cls_specialized_count, cls_specialized_waste, 4013 cls_small_count, cls_small_waste, 4014 cls_medium_count, cls_medium_waste, cls_humongous_count); 4015 } 4016 4017 // Print total fragmentation for data and class metaspaces separately 4018 void MetaspaceAux::print_waste(outputStream* out) { 4019 size_t specialized_waste = 0, small_waste = 0, medium_waste = 0; 4020 size_t specialized_count = 0, small_count = 0, medium_count = 0, humongous_count = 0; 4021 4022 ClassLoaderDataGraphMetaspaceIterator iter; 4023 while (iter.repeat()) { 4024 Metaspace* msp = iter.get_next(); 4025 if (msp != NULL) { 4026 specialized_waste += msp->vsm()->sum_waste_in_chunks_in_use(SpecializedIndex); 4027 specialized_count += msp->vsm()->sum_count_in_chunks_in_use(SpecializedIndex); 4028 small_waste += msp->vsm()->sum_waste_in_chunks_in_use(SmallIndex); 4029 small_count += msp->vsm()->sum_count_in_chunks_in_use(SmallIndex); 4030 medium_waste += msp->vsm()->sum_waste_in_chunks_in_use(MediumIndex); 4031 medium_count += msp->vsm()->sum_count_in_chunks_in_use(MediumIndex); 4032 humongous_count += msp->vsm()->sum_count_in_chunks_in_use(HumongousIndex); 4033 } 4034 } 4035 out->print_cr("Total fragmentation waste (words) doesn't count free space"); 4036 out->print_cr(" data: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", " 4037 SIZE_FORMAT " small(s) " SIZE_FORMAT ", " 4038 SIZE_FORMAT " medium(s) " SIZE_FORMAT ", " 4039 "large count " SIZE_FORMAT, 4040 specialized_count, specialized_waste, small_count, 4041 small_waste, medium_count, medium_waste, humongous_count); 4042 if (Metaspace::using_class_space()) { 4043 print_class_waste(out); 4044 } 4045 } 4046 4047 class MetadataStats { 4048 private: 4049 size_t _capacity; 4050 size_t _used; 4051 size_t _free; 4052 size_t _waste; 4053 4054 public: 4055 MetadataStats() : _capacity(0), _used(0), _free(0), _waste(0) { } 4056 MetadataStats(size_t capacity, size_t used, size_t free, size_t waste) 4057 : _capacity(capacity), _used(used), _free(free), _waste(waste) { } 4058 4059 void add(const MetadataStats& stats) { 4060 _capacity += stats.capacity(); 4061 _used += stats.used(); 4062 _free += stats.free(); 4063 _waste += stats.waste(); 4064 } 4065 4066 size_t capacity() const { return _capacity; } 4067 size_t used() const { return _used; } 4068 size_t free() const { return _free; } 4069 size_t waste() const { return _waste; } 4070 4071 void print_on(outputStream* out, size_t scale) const; 4072 }; 4073 4074 4075 void MetadataStats::print_on(outputStream* out, size_t scale) const { 4076 const char* unit = scale_unit(scale); 4077 out->print_cr("capacity=%10.2f%s used=%10.2f%s free=%10.2f%s waste=%10.2f%s", 4078 (float)capacity() / scale, unit, 4079 (float)used() / scale, unit, 4080 (float)free() / scale, unit, 4081 (float)waste() / scale, unit); 4082 } 4083 4084 class PrintCLDMetaspaceInfoClosure : public CLDClosure { 4085 private: 4086 outputStream* _out; 4087 size_t _scale; 4088 4089 size_t _total_count; 4090 MetadataStats _total_metadata; 4091 MetadataStats _total_class; 4092 4093 size_t _total_anon_count; 4094 MetadataStats _total_anon_metadata; 4095 MetadataStats _total_anon_class; 4096 4097 public: 4098 PrintCLDMetaspaceInfoClosure(outputStream* out, size_t scale = K) 4099 : _out(out), _scale(scale), _total_count(0), _total_anon_count(0) { } 4100 4101 ~PrintCLDMetaspaceInfoClosure() { 4102 print_summary(); 4103 } 4104 4105 void do_cld(ClassLoaderData* cld) { 4106 assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint"); 4107 4108 if (cld->is_unloading()) return; 4109 Metaspace* msp = cld->metaspace_or_null(); 4110 if (msp == NULL) { 4111 return; 4112 } 4113 4114 bool anonymous = false; 4115 if (cld->is_anonymous()) { 4116 _out->print_cr("ClassLoader: for anonymous class"); 4117 anonymous = true; 4118 } else { 4119 ResourceMark rm; 4120 _out->print_cr("ClassLoader: %s", cld->loader_name()); 4121 } 4122 4123 print_metaspace(msp, anonymous); 4124 _out->cr(); 4125 } 4126 4127 private: 4128 void print_metaspace(Metaspace* msp, bool anonymous); 4129 void print_summary() const; 4130 }; 4131 4132 void PrintCLDMetaspaceInfoClosure::print_metaspace(Metaspace* msp, bool anonymous){ 4133 assert(msp != NULL, "Sanity"); 4134 SpaceManager* vsm = msp->vsm(); 4135 const char* unit = scale_unit(_scale); 4136 4137 size_t capacity = vsm->sum_capacity_in_chunks_in_use() * BytesPerWord; 4138 size_t used = vsm->sum_used_in_chunks_in_use() * BytesPerWord; 4139 size_t free = vsm->sum_free_in_chunks_in_use() * BytesPerWord; 4140 size_t waste = vsm->sum_waste_in_chunks_in_use() * BytesPerWord; 4141 4142 _total_count ++; 4143 MetadataStats metadata_stats(capacity, used, free, waste); 4144 _total_metadata.add(metadata_stats); 4145 4146 if (anonymous) { 4147 _total_anon_count ++; 4148 _total_anon_metadata.add(metadata_stats); 4149 } 4150 4151 _out->print(" Metadata "); 4152 metadata_stats.print_on(_out, _scale); 4153 4154 if (Metaspace::using_class_space()) { 4155 vsm = msp->class_vsm(); 4156 4157 capacity = vsm->sum_capacity_in_chunks_in_use() * BytesPerWord; 4158 used = vsm->sum_used_in_chunks_in_use() * BytesPerWord; 4159 free = vsm->sum_free_in_chunks_in_use() * BytesPerWord; 4160 waste = vsm->sum_waste_in_chunks_in_use() * BytesPerWord; 4161 4162 MetadataStats class_stats(capacity, used, free, waste); 4163 _total_class.add(class_stats); 4164 4165 if (anonymous) { 4166 _total_anon_class.add(class_stats); 4167 } 4168 4169 _out->print(" Class data "); 4170 class_stats.print_on(_out, _scale); 4171 } 4172 } 4173 4174 void PrintCLDMetaspaceInfoClosure::print_summary() const { 4175 const char* unit = scale_unit(_scale); 4176 _out->cr(); 4177 _out->print_cr("Summary:"); 4178 4179 MetadataStats total; 4180 total.add(_total_metadata); 4181 total.add(_total_class); 4182 4183 _out->print(" Total class loaders=" SIZE_FORMAT_W(6) " ", _total_count); 4184 total.print_on(_out, _scale); 4185 4186 _out->print(" Metadata "); 4187 _total_metadata.print_on(_out, _scale); 4188 4189 if (Metaspace::using_class_space()) { 4190 _out->print(" Class data "); 4191 _total_class.print_on(_out, _scale); 4192 } 4193 _out->cr(); 4194 4195 MetadataStats total_anon; 4196 total_anon.add(_total_anon_metadata); 4197 total_anon.add(_total_anon_class); 4198 4199 _out->print("For anonymous classes=" SIZE_FORMAT_W(6) " ", _total_anon_count); 4200 total_anon.print_on(_out, _scale); 4201 4202 _out->print(" Metadata "); 4203 _total_anon_metadata.print_on(_out, _scale); 4204 4205 if (Metaspace::using_class_space()) { 4206 _out->print(" Class data "); 4207 _total_anon_class.print_on(_out, _scale); 4208 } 4209 } 4210 4211 void MetaspaceAux::print_metadata_for_nmt(outputStream* out, size_t scale) { 4212 const char* unit = scale_unit(scale); 4213 out->print_cr("Metaspaces:"); 4214 out->print_cr(" Metadata space: reserved=" SIZE_FORMAT_W(10) "%s committed=" SIZE_FORMAT_W(10) "%s", 4215 reserved_bytes(Metaspace::NonClassType) / scale, unit, 4216 committed_bytes(Metaspace::NonClassType) / scale, unit); 4217 if (Metaspace::using_class_space()) { 4218 out->print_cr(" Class space: reserved=" SIZE_FORMAT_W(10) "%s committed=" SIZE_FORMAT_W(10) "%s", 4219 reserved_bytes(Metaspace::ClassType) / scale, unit, 4220 committed_bytes(Metaspace::ClassType) / scale, unit); 4221 } 4222 4223 out->cr(); 4224 ChunkManager::print_all_chunkmanagers(out, scale); 4225 4226 out->cr(); 4227 out->print_cr("Per-classloader metadata:"); 4228 out->cr(); 4229 4230 PrintCLDMetaspaceInfoClosure cl(out, scale); 4231 ClassLoaderDataGraph::cld_do(&cl); 4232 } 4233 4234 4235 // Dump global metaspace things from the end of ClassLoaderDataGraph 4236 void MetaspaceAux::dump(outputStream* out) { 4237 out->print_cr("All Metaspace:"); 4238 out->print("data space: "); print_on(out, Metaspace::NonClassType); 4239 out->print("class space: "); print_on(out, Metaspace::ClassType); 4240 print_waste(out); 4241 } 4242 4243 // Prints an ASCII representation of the given space. 4244 void MetaspaceAux::print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype) { 4245 MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag); 4246 const bool for_class = mdtype == Metaspace::ClassType ? true : false; 4247 VirtualSpaceList* const vsl = for_class ? Metaspace::class_space_list() : Metaspace::space_list(); 4248 if (vsl != NULL) { 4249 if (for_class) { 4250 if (!Metaspace::using_class_space()) { 4251 out->print_cr("No Class Space."); 4252 return; 4253 } 4254 out->print_raw("---- Metaspace Map (Class Space) ----"); 4255 } else { 4256 out->print_raw("---- Metaspace Map (Non-Class Space) ----"); 4257 } 4258 // Print legend: 4259 out->cr(); 4260 out->print_cr("Chunk Types (uppercase chunks are in use): x-specialized, s-small, m-medium, h-humongous."); 4261 out->cr(); 4262 VirtualSpaceList* const vsl = for_class ? Metaspace::class_space_list() : Metaspace::space_list(); 4263 vsl->print_map(out); 4264 out->cr(); 4265 } 4266 } 4267 4268 void MetaspaceAux::verify_free_chunks() { 4269 Metaspace::chunk_manager_metadata()->verify(); 4270 if (Metaspace::using_class_space()) { 4271 Metaspace::chunk_manager_class()->verify(); 4272 } 4273 } 4274 4275 void MetaspaceAux::verify_capacity() { 4276 #ifdef ASSERT 4277 size_t running_sum_capacity_bytes = capacity_bytes(); 4278 // For purposes of the running sum of capacity, verify against capacity 4279 size_t capacity_in_use_bytes = capacity_bytes_slow(); 4280 assert(running_sum_capacity_bytes == capacity_in_use_bytes, 4281 "capacity_words() * BytesPerWord " SIZE_FORMAT 4282 " capacity_bytes_slow()" SIZE_FORMAT, 4283 running_sum_capacity_bytes, capacity_in_use_bytes); 4284 for (Metaspace::MetadataType i = Metaspace::ClassType; 4285 i < Metaspace:: MetadataTypeCount; 4286 i = (Metaspace::MetadataType)(i + 1)) { 4287 size_t capacity_in_use_bytes = capacity_bytes_slow(i); 4288 assert(capacity_bytes(i) == capacity_in_use_bytes, 4289 "capacity_bytes(%u) " SIZE_FORMAT 4290 " capacity_bytes_slow(%u)" SIZE_FORMAT, 4291 i, capacity_bytes(i), i, capacity_in_use_bytes); 4292 } 4293 #endif 4294 } 4295 4296 void MetaspaceAux::verify_used() { 4297 #ifdef ASSERT 4298 size_t running_sum_used_bytes = used_bytes(); 4299 // For purposes of the running sum of used, verify against used 4300 size_t used_in_use_bytes = used_bytes_slow(); 4301 assert(used_bytes() == used_in_use_bytes, 4302 "used_bytes() " SIZE_FORMAT 4303 " used_bytes_slow()" SIZE_FORMAT, 4304 used_bytes(), used_in_use_bytes); 4305 for (Metaspace::MetadataType i = Metaspace::ClassType; 4306 i < Metaspace:: MetadataTypeCount; 4307 i = (Metaspace::MetadataType)(i + 1)) { 4308 size_t used_in_use_bytes = used_bytes_slow(i); 4309 assert(used_bytes(i) == used_in_use_bytes, 4310 "used_bytes(%u) " SIZE_FORMAT 4311 " used_bytes_slow(%u)" SIZE_FORMAT, 4312 i, used_bytes(i), i, used_in_use_bytes); 4313 } 4314 #endif 4315 } 4316 4317 void MetaspaceAux::verify_metrics() { 4318 verify_capacity(); 4319 verify_used(); 4320 } 4321 4322 4323 // Metaspace methods 4324 4325 size_t Metaspace::_first_chunk_word_size = 0; 4326 size_t Metaspace::_first_class_chunk_word_size = 0; 4327 4328 size_t Metaspace::_commit_alignment = 0; 4329 size_t Metaspace::_reserve_alignment = 0; 4330 4331 Metaspace::Metaspace(Mutex* lock, MetaspaceType type) { 4332 initialize(lock, type); 4333 } 4334 4335 Metaspace::~Metaspace() { 4336 delete _vsm; 4337 if (using_class_space()) { 4338 delete _class_vsm; 4339 } 4340 } 4341 4342 VirtualSpaceList* Metaspace::_space_list = NULL; 4343 VirtualSpaceList* Metaspace::_class_space_list = NULL; 4344 4345 ChunkManager* Metaspace::_chunk_manager_metadata = NULL; 4346 ChunkManager* Metaspace::_chunk_manager_class = NULL; 4347 4348 #define VIRTUALSPACEMULTIPLIER 2 4349 4350 #ifdef _LP64 4351 static const uint64_t UnscaledClassSpaceMax = (uint64_t(max_juint) + 1); 4352 4353 void Metaspace::set_narrow_klass_base_and_shift(address metaspace_base, address cds_base) { 4354 assert(!DumpSharedSpaces, "narrow_klass is set by MetaspaceShared class."); 4355 // Figure out the narrow_klass_base and the narrow_klass_shift. The 4356 // narrow_klass_base is the lower of the metaspace base and the cds base 4357 // (if cds is enabled). The narrow_klass_shift depends on the distance 4358 // between the lower base and higher address. 4359 address lower_base; 4360 address higher_address; 4361 #if INCLUDE_CDS 4362 if (UseSharedSpaces) { 4363 higher_address = MAX2((address)(cds_base + MetaspaceShared::core_spaces_size()), 4364 (address)(metaspace_base + compressed_class_space_size())); 4365 lower_base = MIN2(metaspace_base, cds_base); 4366 } else 4367 #endif 4368 { 4369 higher_address = metaspace_base + compressed_class_space_size(); 4370 lower_base = metaspace_base; 4371 4372 uint64_t klass_encoding_max = UnscaledClassSpaceMax << LogKlassAlignmentInBytes; 4373 // If compressed class space fits in lower 32G, we don't need a base. 4374 if (higher_address <= (address)klass_encoding_max) { 4375 lower_base = 0; // Effectively lower base is zero. 4376 } 4377 } 4378 4379 Universe::set_narrow_klass_base(lower_base); 4380 4381 // CDS uses LogKlassAlignmentInBytes for narrow_klass_shift. See 4382 // MetaspaceShared::initialize_dumptime_shared_and_meta_spaces() for 4383 // how dump time narrow_klass_shift is set. Although, CDS can work 4384 // with zero-shift mode also, to be consistent with AOT it uses 4385 // LogKlassAlignmentInBytes for klass shift so archived java heap objects 4386 // can be used at same time as AOT code. 4387 if (!UseSharedSpaces 4388 && (uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax) { 4389 Universe::set_narrow_klass_shift(0); 4390 } else { 4391 Universe::set_narrow_klass_shift(LogKlassAlignmentInBytes); 4392 } 4393 AOTLoader::set_narrow_klass_shift(); 4394 } 4395 4396 #if INCLUDE_CDS 4397 // Return TRUE if the specified metaspace_base and cds_base are close enough 4398 // to work with compressed klass pointers. 4399 bool Metaspace::can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base) { 4400 assert(cds_base != 0 && UseSharedSpaces, "Only use with CDS"); 4401 assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs"); 4402 address lower_base = MIN2((address)metaspace_base, cds_base); 4403 address higher_address = MAX2((address)(cds_base + MetaspaceShared::core_spaces_size()), 4404 (address)(metaspace_base + compressed_class_space_size())); 4405 return ((uint64_t)(higher_address - lower_base) <= UnscaledClassSpaceMax); 4406 } 4407 #endif 4408 4409 // Try to allocate the metaspace at the requested addr. 4410 void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base) { 4411 assert(!DumpSharedSpaces, "compress klass space is allocated by MetaspaceShared class."); 4412 assert(using_class_space(), "called improperly"); 4413 assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs"); 4414 assert(compressed_class_space_size() < KlassEncodingMetaspaceMax, 4415 "Metaspace size is too big"); 4416 assert_is_aligned(requested_addr, _reserve_alignment); 4417 assert_is_aligned(cds_base, _reserve_alignment); 4418 assert_is_aligned(compressed_class_space_size(), _reserve_alignment); 4419 4420 // Don't use large pages for the class space. 4421 bool large_pages = false; 4422 4423 #if !(defined(AARCH64) || defined(AIX)) 4424 ReservedSpace metaspace_rs = ReservedSpace(compressed_class_space_size(), 4425 _reserve_alignment, 4426 large_pages, 4427 requested_addr); 4428 #else // AARCH64 4429 ReservedSpace metaspace_rs; 4430 4431 // Our compressed klass pointers may fit nicely into the lower 32 4432 // bits. 4433 if ((uint64_t)requested_addr + compressed_class_space_size() < 4*G) { 4434 metaspace_rs = ReservedSpace(compressed_class_space_size(), 4435 _reserve_alignment, 4436 large_pages, 4437 requested_addr); 4438 } 4439 4440 if (! metaspace_rs.is_reserved()) { 4441 // Aarch64: Try to align metaspace so that we can decode a compressed 4442 // klass with a single MOVK instruction. We can do this iff the 4443 // compressed class base is a multiple of 4G. 4444 // Aix: Search for a place where we can find memory. If we need to load 4445 // the base, 4G alignment is helpful, too. 4446 size_t increment = AARCH64_ONLY(4*)G; 4447 for (char *a = align_up(requested_addr, increment); 4448 a < (char*)(1024*G); 4449 a += increment) { 4450 if (a == (char *)(32*G)) { 4451 // Go faster from here on. Zero-based is no longer possible. 4452 increment = 4*G; 4453 } 4454 4455 #if INCLUDE_CDS 4456 if (UseSharedSpaces 4457 && ! can_use_cds_with_metaspace_addr(a, cds_base)) { 4458 // We failed to find an aligned base that will reach. Fall 4459 // back to using our requested addr. 4460 metaspace_rs = ReservedSpace(compressed_class_space_size(), 4461 _reserve_alignment, 4462 large_pages, 4463 requested_addr); 4464 break; 4465 } 4466 #endif 4467 4468 metaspace_rs = ReservedSpace(compressed_class_space_size(), 4469 _reserve_alignment, 4470 large_pages, 4471 a); 4472 if (metaspace_rs.is_reserved()) 4473 break; 4474 } 4475 } 4476 4477 #endif // AARCH64 4478 4479 if (!metaspace_rs.is_reserved()) { 4480 #if INCLUDE_CDS 4481 if (UseSharedSpaces) { 4482 size_t increment = align_up(1*G, _reserve_alignment); 4483 4484 // Keep trying to allocate the metaspace, increasing the requested_addr 4485 // by 1GB each time, until we reach an address that will no longer allow 4486 // use of CDS with compressed klass pointers. 4487 char *addr = requested_addr; 4488 while (!metaspace_rs.is_reserved() && (addr + increment > addr) && 4489 can_use_cds_with_metaspace_addr(addr + increment, cds_base)) { 4490 addr = addr + increment; 4491 metaspace_rs = ReservedSpace(compressed_class_space_size(), 4492 _reserve_alignment, large_pages, addr); 4493 } 4494 } 4495 #endif 4496 // If no successful allocation then try to allocate the space anywhere. If 4497 // that fails then OOM doom. At this point we cannot try allocating the 4498 // metaspace as if UseCompressedClassPointers is off because too much 4499 // initialization has happened that depends on UseCompressedClassPointers. 4500 // So, UseCompressedClassPointers cannot be turned off at this point. 4501 if (!metaspace_rs.is_reserved()) { 4502 metaspace_rs = ReservedSpace(compressed_class_space_size(), 4503 _reserve_alignment, large_pages); 4504 if (!metaspace_rs.is_reserved()) { 4505 vm_exit_during_initialization(err_msg("Could not allocate metaspace: " SIZE_FORMAT " bytes", 4506 compressed_class_space_size())); 4507 } 4508 } 4509 } 4510 4511 // If we got here then the metaspace got allocated. 4512 MemTracker::record_virtual_memory_type((address)metaspace_rs.base(), mtClass); 4513 4514 #if INCLUDE_CDS 4515 // Verify that we can use shared spaces. Otherwise, turn off CDS. 4516 if (UseSharedSpaces && !can_use_cds_with_metaspace_addr(metaspace_rs.base(), cds_base)) { 4517 FileMapInfo::stop_sharing_and_unmap( 4518 "Could not allocate metaspace at a compatible address"); 4519 } 4520 #endif 4521 set_narrow_klass_base_and_shift((address)metaspace_rs.base(), 4522 UseSharedSpaces ? (address)cds_base : 0); 4523 4524 initialize_class_space(metaspace_rs); 4525 4526 LogTarget(Trace, gc, metaspace) lt; 4527 if (lt.is_enabled()) { 4528 ResourceMark rm; 4529 LogStream ls(lt); 4530 print_compressed_class_space(&ls, requested_addr); 4531 } 4532 } 4533 4534 void Metaspace::print_compressed_class_space(outputStream* st, const char* requested_addr) { 4535 st->print_cr("Narrow klass base: " PTR_FORMAT ", Narrow klass shift: %d", 4536 p2i(Universe::narrow_klass_base()), Universe::narrow_klass_shift()); 4537 if (_class_space_list != NULL) { 4538 address base = (address)_class_space_list->current_virtual_space()->bottom(); 4539 st->print("Compressed class space size: " SIZE_FORMAT " Address: " PTR_FORMAT, 4540 compressed_class_space_size(), p2i(base)); 4541 if (requested_addr != 0) { 4542 st->print(" Req Addr: " PTR_FORMAT, p2i(requested_addr)); 4543 } 4544 st->cr(); 4545 } 4546 } 4547 4548 // For UseCompressedClassPointers the class space is reserved above the top of 4549 // the Java heap. The argument passed in is at the base of the compressed space. 4550 void Metaspace::initialize_class_space(ReservedSpace rs) { 4551 // The reserved space size may be bigger because of alignment, esp with UseLargePages 4552 assert(rs.size() >= CompressedClassSpaceSize, 4553 SIZE_FORMAT " != " SIZE_FORMAT, rs.size(), CompressedClassSpaceSize); 4554 assert(using_class_space(), "Must be using class space"); 4555 _class_space_list = new VirtualSpaceList(rs); 4556 _chunk_manager_class = new ChunkManager(true/*is_class*/); 4557 4558 if (!_class_space_list->initialization_succeeded()) { 4559 vm_exit_during_initialization("Failed to setup compressed class space virtual space list."); 4560 } 4561 } 4562 4563 #endif 4564 4565 void Metaspace::ergo_initialize() { 4566 if (DumpSharedSpaces) { 4567 // Using large pages when dumping the shared archive is currently not implemented. 4568 FLAG_SET_ERGO(bool, UseLargePagesInMetaspace, false); 4569 } 4570 4571 size_t page_size = os::vm_page_size(); 4572 if (UseLargePages && UseLargePagesInMetaspace) { 4573 page_size = os::large_page_size(); 4574 } 4575 4576 _commit_alignment = page_size; 4577 _reserve_alignment = MAX2(page_size, (size_t)os::vm_allocation_granularity()); 4578 4579 // Do not use FLAG_SET_ERGO to update MaxMetaspaceSize, since this will 4580 // override if MaxMetaspaceSize was set on the command line or not. 4581 // This information is needed later to conform to the specification of the 4582 // java.lang.management.MemoryUsage API. 4583 // 4584 // Ideally, we would be able to set the default value of MaxMetaspaceSize in 4585 // globals.hpp to the aligned value, but this is not possible, since the 4586 // alignment depends on other flags being parsed. 4587 MaxMetaspaceSize = align_down_bounded(MaxMetaspaceSize, _reserve_alignment); 4588 4589 if (MetaspaceSize > MaxMetaspaceSize) { 4590 MetaspaceSize = MaxMetaspaceSize; 4591 } 4592 4593 MetaspaceSize = align_down_bounded(MetaspaceSize, _commit_alignment); 4594 4595 assert(MetaspaceSize <= MaxMetaspaceSize, "MetaspaceSize should be limited by MaxMetaspaceSize"); 4596 4597 MinMetaspaceExpansion = align_down_bounded(MinMetaspaceExpansion, _commit_alignment); 4598 MaxMetaspaceExpansion = align_down_bounded(MaxMetaspaceExpansion, _commit_alignment); 4599 4600 CompressedClassSpaceSize = align_down_bounded(CompressedClassSpaceSize, _reserve_alignment); 4601 4602 // Initial virtual space size will be calculated at global_initialize() 4603 size_t min_metaspace_sz = 4604 VIRTUALSPACEMULTIPLIER * InitialBootClassLoaderMetaspaceSize; 4605 if (UseCompressedClassPointers) { 4606 if ((min_metaspace_sz + CompressedClassSpaceSize) > MaxMetaspaceSize) { 4607 if (min_metaspace_sz >= MaxMetaspaceSize) { 4608 vm_exit_during_initialization("MaxMetaspaceSize is too small."); 4609 } else { 4610 FLAG_SET_ERGO(size_t, CompressedClassSpaceSize, 4611 MaxMetaspaceSize - min_metaspace_sz); 4612 } 4613 } 4614 } else if (min_metaspace_sz >= MaxMetaspaceSize) { 4615 FLAG_SET_ERGO(size_t, InitialBootClassLoaderMetaspaceSize, 4616 min_metaspace_sz); 4617 } 4618 4619 set_compressed_class_space_size(CompressedClassSpaceSize); 4620 } 4621 4622 void Metaspace::global_initialize() { 4623 MetaspaceGC::initialize(); 4624 4625 #if INCLUDE_CDS 4626 if (DumpSharedSpaces) { 4627 MetaspaceShared::initialize_dumptime_shared_and_meta_spaces(); 4628 } else if (UseSharedSpaces) { 4629 // If any of the archived space fails to map, UseSharedSpaces 4630 // is reset to false. Fall through to the 4631 // (!DumpSharedSpaces && !UseSharedSpaces) case to set up class 4632 // metaspace. 4633 MetaspaceShared::initialize_runtime_shared_and_meta_spaces(); 4634 } 4635 4636 if (!DumpSharedSpaces && !UseSharedSpaces) 4637 #endif // INCLUDE_CDS 4638 { 4639 #ifdef _LP64 4640 if (using_class_space()) { 4641 char* base = (char*)align_up(Universe::heap()->reserved_region().end(), _reserve_alignment); 4642 allocate_metaspace_compressed_klass_ptrs(base, 0); 4643 } 4644 #endif // _LP64 4645 } 4646 4647 // Initialize these before initializing the VirtualSpaceList 4648 _first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord; 4649 _first_chunk_word_size = align_word_size_up(_first_chunk_word_size); 4650 // Make the first class chunk bigger than a medium chunk so it's not put 4651 // on the medium chunk list. The next chunk will be small and progress 4652 // from there. This size calculated by -version. 4653 _first_class_chunk_word_size = MIN2((size_t)MediumChunk*6, 4654 (CompressedClassSpaceSize/BytesPerWord)*2); 4655 _first_class_chunk_word_size = align_word_size_up(_first_class_chunk_word_size); 4656 // Arbitrarily set the initial virtual space to a multiple 4657 // of the boot class loader size. 4658 size_t word_size = VIRTUALSPACEMULTIPLIER * _first_chunk_word_size; 4659 word_size = align_up(word_size, Metaspace::reserve_alignment_words()); 4660 4661 // Initialize the list of virtual spaces. 4662 _space_list = new VirtualSpaceList(word_size); 4663 _chunk_manager_metadata = new ChunkManager(false/*metaspace*/); 4664 4665 if (!_space_list->initialization_succeeded()) { 4666 vm_exit_during_initialization("Unable to setup metadata virtual space list.", NULL); 4667 } 4668 4669 _tracer = new MetaspaceTracer(); 4670 } 4671 4672 void Metaspace::post_initialize() { 4673 MetaspaceGC::post_initialize(); 4674 } 4675 4676 void Metaspace::initialize_first_chunk(MetaspaceType type, MetadataType mdtype) { 4677 Metachunk* chunk = get_initialization_chunk(type, mdtype); 4678 if (chunk != NULL) { 4679 // Add to this manager's list of chunks in use and current_chunk(). 4680 get_space_manager(mdtype)->add_chunk(chunk, true); 4681 } 4682 } 4683 4684 Metachunk* Metaspace::get_initialization_chunk(MetaspaceType type, MetadataType mdtype) { 4685 size_t chunk_word_size = get_space_manager(mdtype)->get_initial_chunk_size(type); 4686 4687 // Get a chunk from the chunk freelist 4688 Metachunk* chunk = get_chunk_manager(mdtype)->chunk_freelist_allocate(chunk_word_size); 4689 4690 if (chunk == NULL) { 4691 chunk = get_space_list(mdtype)->get_new_chunk(chunk_word_size, 4692 get_space_manager(mdtype)->medium_chunk_bunch()); 4693 } 4694 4695 return chunk; 4696 } 4697 4698 void Metaspace::verify_global_initialization() { 4699 assert(space_list() != NULL, "Metadata VirtualSpaceList has not been initialized"); 4700 assert(chunk_manager_metadata() != NULL, "Metadata ChunkManager has not been initialized"); 4701 4702 if (using_class_space()) { 4703 assert(class_space_list() != NULL, "Class VirtualSpaceList has not been initialized"); 4704 assert(chunk_manager_class() != NULL, "Class ChunkManager has not been initialized"); 4705 } 4706 } 4707 4708 void Metaspace::initialize(Mutex* lock, MetaspaceType type) { 4709 verify_global_initialization(); 4710 4711 // Allocate SpaceManager for metadata objects. 4712 _vsm = new SpaceManager(NonClassType, type, lock); 4713 4714 if (using_class_space()) { 4715 // Allocate SpaceManager for classes. 4716 _class_vsm = new SpaceManager(ClassType, type, lock); 4717 } 4718 4719 MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag); 4720 4721 // Allocate chunk for metadata objects 4722 initialize_first_chunk(type, NonClassType); 4723 4724 // Allocate chunk for class metadata objects 4725 if (using_class_space()) { 4726 initialize_first_chunk(type, ClassType); 4727 } 4728 } 4729 4730 size_t Metaspace::align_word_size_up(size_t word_size) { 4731 size_t byte_size = word_size * wordSize; 4732 return ReservedSpace::allocation_align_size_up(byte_size) / wordSize; 4733 } 4734 4735 MetaWord* Metaspace::allocate(size_t word_size, MetadataType mdtype) { 4736 assert(!_frozen, "sanity"); 4737 // Don't use class_vsm() unless UseCompressedClassPointers is true. 4738 if (is_class_space_allocation(mdtype)) { 4739 return class_vsm()->allocate(word_size); 4740 } else { 4741 return vsm()->allocate(word_size); 4742 } 4743 } 4744 4745 MetaWord* Metaspace::expand_and_allocate(size_t word_size, MetadataType mdtype) { 4746 assert(!_frozen, "sanity"); 4747 size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size * BytesPerWord); 4748 assert(delta_bytes > 0, "Must be"); 4749 4750 size_t before = 0; 4751 size_t after = 0; 4752 MetaWord* res; 4753 bool incremented; 4754 4755 // Each thread increments the HWM at most once. Even if the thread fails to increment 4756 // the HWM, an allocation is still attempted. This is because another thread must then 4757 // have incremented the HWM and therefore the allocation might still succeed. 4758 do { 4759 incremented = MetaspaceGC::inc_capacity_until_GC(delta_bytes, &after, &before); 4760 res = allocate(word_size, mdtype); 4761 } while (!incremented && res == NULL); 4762 4763 if (incremented) { 4764 tracer()->report_gc_threshold(before, after, 4765 MetaspaceGCThresholdUpdater::ExpandAndAllocate); 4766 log_trace(gc, metaspace)("Increase capacity to GC from " SIZE_FORMAT " to " SIZE_FORMAT, before, after); 4767 } 4768 4769 return res; 4770 } 4771 4772 size_t Metaspace::used_words_slow(MetadataType mdtype) const { 4773 if (mdtype == ClassType) { 4774 return using_class_space() ? class_vsm()->sum_used_in_chunks_in_use() : 0; 4775 } else { 4776 return vsm()->sum_used_in_chunks_in_use(); // includes overhead! 4777 } 4778 } 4779 4780 size_t Metaspace::free_words_slow(MetadataType mdtype) const { 4781 assert(!_frozen, "sanity"); 4782 if (mdtype == ClassType) { 4783 return using_class_space() ? class_vsm()->sum_free_in_chunks_in_use() : 0; 4784 } else { 4785 return vsm()->sum_free_in_chunks_in_use(); 4786 } 4787 } 4788 4789 // Space capacity in the Metaspace. It includes 4790 // space in the list of chunks from which allocations 4791 // have been made. Don't include space in the global freelist and 4792 // in the space available in the dictionary which 4793 // is already counted in some chunk. 4794 size_t Metaspace::capacity_words_slow(MetadataType mdtype) const { 4795 if (mdtype == ClassType) { 4796 return using_class_space() ? class_vsm()->sum_capacity_in_chunks_in_use() : 0; 4797 } else { 4798 return vsm()->sum_capacity_in_chunks_in_use(); 4799 } 4800 } 4801 4802 size_t Metaspace::used_bytes_slow(MetadataType mdtype) const { 4803 return used_words_slow(mdtype) * BytesPerWord; 4804 } 4805 4806 size_t Metaspace::capacity_bytes_slow(MetadataType mdtype) const { 4807 return capacity_words_slow(mdtype) * BytesPerWord; 4808 } 4809 4810 size_t Metaspace::allocated_blocks_bytes() const { 4811 return vsm()->allocated_blocks_bytes() + 4812 (using_class_space() ? class_vsm()->allocated_blocks_bytes() : 0); 4813 } 4814 4815 size_t Metaspace::allocated_chunks_bytes() const { 4816 return vsm()->allocated_chunks_bytes() + 4817 (using_class_space() ? class_vsm()->allocated_chunks_bytes() : 0); 4818 } 4819 4820 void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) { 4821 assert(!_frozen, "sanity"); 4822 assert(!SafepointSynchronize::is_at_safepoint() 4823 || Thread::current()->is_VM_thread(), "should be the VM thread"); 4824 4825 MutexLockerEx ml(vsm()->lock(), Mutex::_no_safepoint_check_flag); 4826 4827 if (is_class && using_class_space()) { 4828 class_vsm()->deallocate(ptr, word_size); 4829 } else { 4830 vsm()->deallocate(ptr, word_size); 4831 } 4832 } 4833 4834 MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size, 4835 MetaspaceObj::Type type, TRAPS) { 4836 assert(!_frozen, "sanity"); 4837 if (HAS_PENDING_EXCEPTION) { 4838 assert(false, "Should not allocate with exception pending"); 4839 return NULL; // caller does a CHECK_NULL too 4840 } 4841 4842 assert(loader_data != NULL, "Should never pass around a NULL loader_data. " 4843 "ClassLoaderData::the_null_class_loader_data() should have been used."); 4844 4845 MetadataType mdtype = (type == MetaspaceObj::ClassType) ? ClassType : NonClassType; 4846 4847 // Try to allocate metadata. 4848 MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype); 4849 4850 if (result == NULL) { 4851 if (DumpSharedSpaces && THREAD->is_VM_thread()) { 4852 tty->print_cr("Failed allocating metaspace object type %s of size " SIZE_FORMAT ". CDS dump aborted.", 4853 MetaspaceObj::type_name(type), word_size * BytesPerWord); 4854 vm_exit(1); 4855 } 4856 4857 tracer()->report_metaspace_allocation_failure(loader_data, word_size, type, mdtype); 4858 4859 // Allocation failed. 4860 if (is_init_completed()) { 4861 // Only start a GC if the bootstrapping has completed. 4862 4863 // Try to clean out some memory and retry. 4864 result = Universe::heap()->satisfy_failed_metadata_allocation(loader_data, word_size, mdtype); 4865 } 4866 } 4867 4868 if (result == NULL) { 4869 report_metadata_oome(loader_data, word_size, type, mdtype, CHECK_NULL); 4870 } 4871 4872 // Zero initialize. 4873 Copy::fill_to_words((HeapWord*)result, word_size, 0); 4874 4875 return result; 4876 } 4877 4878 size_t Metaspace::class_chunk_size(size_t word_size) { 4879 assert(using_class_space(), "Has to use class space"); 4880 return class_vsm()->calc_chunk_size(word_size); 4881 } 4882 4883 void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, MetadataType mdtype, TRAPS) { 4884 tracer()->report_metadata_oom(loader_data, word_size, type, mdtype); 4885 4886 // If result is still null, we are out of memory. 4887 Log(gc, metaspace, freelist) log; 4888 if (log.is_info()) { 4889 log.info("Metaspace (%s) allocation failed for size " SIZE_FORMAT, 4890 is_class_space_allocation(mdtype) ? "class" : "data", word_size); 4891 ResourceMark rm; 4892 if (log.is_debug()) { 4893 if (loader_data->metaspace_or_null() != NULL) { 4894 LogStream ls(log.debug()); 4895 loader_data->print_value_on(&ls); 4896 } 4897 } 4898 LogStream ls(log.info()); 4899 MetaspaceAux::dump(&ls); 4900 MetaspaceAux::print_metaspace_map(&ls, mdtype); 4901 ChunkManager::print_all_chunkmanagers(&ls); 4902 } 4903 4904 bool out_of_compressed_class_space = false; 4905 if (is_class_space_allocation(mdtype)) { 4906 Metaspace* metaspace = loader_data->metaspace_non_null(); 4907 out_of_compressed_class_space = 4908 MetaspaceAux::committed_bytes(Metaspace::ClassType) + 4909 (metaspace->class_chunk_size(word_size) * BytesPerWord) > 4910 CompressedClassSpaceSize; 4911 } 4912 4913 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support 4914 const char* space_string = out_of_compressed_class_space ? 4915 "Compressed class space" : "Metaspace"; 4916 4917 report_java_out_of_memory(space_string); 4918 4919 if (JvmtiExport::should_post_resource_exhausted()) { 4920 JvmtiExport::post_resource_exhausted( 4921 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR, 4922 space_string); 4923 } 4924 4925 if (!is_init_completed()) { 4926 vm_exit_during_initialization("OutOfMemoryError", space_string); 4927 } 4928 4929 if (out_of_compressed_class_space) { 4930 THROW_OOP(Universe::out_of_memory_error_class_metaspace()); 4931 } else { 4932 THROW_OOP(Universe::out_of_memory_error_metaspace()); 4933 } 4934 } 4935 4936 const char* Metaspace::metadata_type_name(Metaspace::MetadataType mdtype) { 4937 switch (mdtype) { 4938 case Metaspace::ClassType: return "Class"; 4939 case Metaspace::NonClassType: return "Metadata"; 4940 default: 4941 assert(false, "Got bad mdtype: %d", (int) mdtype); 4942 return NULL; 4943 } 4944 } 4945 4946 void Metaspace::purge(MetadataType mdtype) { 4947 get_space_list(mdtype)->purge(get_chunk_manager(mdtype)); 4948 } 4949 4950 void Metaspace::purge() { 4951 MutexLockerEx cl(SpaceManager::expand_lock(), 4952 Mutex::_no_safepoint_check_flag); 4953 purge(NonClassType); 4954 if (using_class_space()) { 4955 purge(ClassType); 4956 } 4957 } 4958 4959 void Metaspace::print_on(outputStream* out) const { 4960 // Print both class virtual space counts and metaspace. 4961 if (Verbose) { 4962 vsm()->print_on(out); 4963 if (using_class_space()) { 4964 class_vsm()->print_on(out); 4965 } 4966 } 4967 } 4968 4969 bool Metaspace::contains(const void* ptr) { 4970 if (MetaspaceShared::is_in_shared_metaspace(ptr)) { 4971 return true; 4972 } 4973 return contains_non_shared(ptr); 4974 } 4975 4976 bool Metaspace::contains_non_shared(const void* ptr) { 4977 if (using_class_space() && get_space_list(ClassType)->contains(ptr)) { 4978 return true; 4979 } 4980 4981 return get_space_list(NonClassType)->contains(ptr); 4982 } 4983 4984 void Metaspace::verify() { 4985 vsm()->verify(); 4986 if (using_class_space()) { 4987 class_vsm()->verify(); 4988 } 4989 } 4990 4991 void Metaspace::dump(outputStream* const out) const { 4992 out->print_cr("\nVirtual space manager: " INTPTR_FORMAT, p2i(vsm())); 4993 vsm()->dump(out); 4994 if (using_class_space()) { 4995 out->print_cr("\nClass space manager: " INTPTR_FORMAT, p2i(class_vsm())); 4996 class_vsm()->dump(out); 4997 } 4998 } 4999 5000 #ifdef ASSERT 5001 static void do_verify_chunk(Metachunk* chunk) { 5002 guarantee(chunk != NULL, "Sanity"); 5003 // Verify chunk itself; then verify that it is consistent with the 5004 // occupany map of its containing node. 5005 chunk->verify(); 5006 VirtualSpaceNode* const vsn = chunk->container(); 5007 OccupancyMap* const ocmap = vsn->occupancy_map(); 5008 ocmap->verify_for_chunk(chunk); 5009 } 5010 #endif 5011 5012 static void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse) { 5013 chunk->set_is_tagged_free(!inuse); 5014 OccupancyMap* const ocmap = chunk->container()->occupancy_map(); 5015 ocmap->set_region_in_use((MetaWord*)chunk, chunk->word_size(), inuse); 5016 } 5017 5018 /////////////// Unit tests /////////////// 5019 5020 #ifndef PRODUCT 5021 5022 class TestMetaspaceAuxTest : AllStatic { 5023 public: 5024 static void test_reserved() { 5025 size_t reserved = MetaspaceAux::reserved_bytes(); 5026 5027 assert(reserved > 0, "assert"); 5028 5029 size_t committed = MetaspaceAux::committed_bytes(); 5030 assert(committed <= reserved, "assert"); 5031 5032 size_t reserved_metadata = MetaspaceAux::reserved_bytes(Metaspace::NonClassType); 5033 assert(reserved_metadata > 0, "assert"); 5034 assert(reserved_metadata <= reserved, "assert"); 5035 5036 if (UseCompressedClassPointers) { 5037 size_t reserved_class = MetaspaceAux::reserved_bytes(Metaspace::ClassType); 5038 assert(reserved_class > 0, "assert"); 5039 assert(reserved_class < reserved, "assert"); 5040 } 5041 } 5042 5043 static void test_committed() { 5044 size_t committed = MetaspaceAux::committed_bytes(); 5045 5046 assert(committed > 0, "assert"); 5047 5048 size_t reserved = MetaspaceAux::reserved_bytes(); 5049 assert(committed <= reserved, "assert"); 5050 5051 size_t committed_metadata = MetaspaceAux::committed_bytes(Metaspace::NonClassType); 5052 assert(committed_metadata > 0, "assert"); 5053 assert(committed_metadata <= committed, "assert"); 5054 5055 if (UseCompressedClassPointers) { 5056 size_t committed_class = MetaspaceAux::committed_bytes(Metaspace::ClassType); 5057 assert(committed_class > 0, "assert"); 5058 assert(committed_class < committed, "assert"); 5059 } 5060 } 5061 5062 static void test_virtual_space_list_large_chunk() { 5063 VirtualSpaceList* vs_list = new VirtualSpaceList(os::vm_allocation_granularity()); 5064 MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag); 5065 // A size larger than VirtualSpaceSize (256k) and add one page to make it _not_ be 5066 // vm_allocation_granularity aligned on Windows. 5067 size_t large_size = (size_t)(2*256*K + (os::vm_page_size()/BytesPerWord)); 5068 large_size += (os::vm_page_size()/BytesPerWord); 5069 vs_list->get_new_chunk(large_size, 0); 5070 } 5071 5072 static void test() { 5073 test_reserved(); 5074 test_committed(); 5075 test_virtual_space_list_large_chunk(); 5076 } 5077 }; 5078 5079 void TestMetaspaceAux_test() { 5080 TestMetaspaceAuxTest::test(); 5081 } 5082 5083 class TestVirtualSpaceNodeTest { 5084 static void chunk_up(size_t words_left, size_t& num_medium_chunks, 5085 size_t& num_small_chunks, 5086 size_t& num_specialized_chunks) { 5087 num_medium_chunks = words_left / MediumChunk; 5088 words_left = words_left % MediumChunk; 5089 5090 num_small_chunks = words_left / SmallChunk; 5091 words_left = words_left % SmallChunk; 5092 // how many specialized chunks can we get? 5093 num_specialized_chunks = words_left / SpecializedChunk; 5094 assert(words_left % SpecializedChunk == 0, "should be nothing left"); 5095 } 5096 5097 public: 5098 static void test() { 5099 MutexLockerEx ml(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag); 5100 const size_t vsn_test_size_words = MediumChunk * 4; 5101 const size_t vsn_test_size_bytes = vsn_test_size_words * BytesPerWord; 5102 5103 // The chunk sizes must be multiples of eachother, or this will fail 5104 STATIC_ASSERT(MediumChunk % SmallChunk == 0); 5105 STATIC_ASSERT(SmallChunk % SpecializedChunk == 0); 5106 5107 { // No committed memory in VSN 5108 ChunkManager cm(false); 5109 VirtualSpaceNode vsn(false, vsn_test_size_bytes); 5110 vsn.initialize(); 5111 vsn.retire(&cm); 5112 assert(cm.sum_free_chunks_count() == 0, "did not commit any memory in the VSN"); 5113 } 5114 5115 { // All of VSN is committed, half is used by chunks 5116 ChunkManager cm(false); 5117 VirtualSpaceNode vsn(false, vsn_test_size_bytes); 5118 vsn.initialize(); 5119 vsn.expand_by(vsn_test_size_words, vsn_test_size_words); 5120 vsn.get_chunk_vs(MediumChunk); 5121 vsn.get_chunk_vs(MediumChunk); 5122 vsn.retire(&cm); 5123 assert(cm.sum_free_chunks_count() == 2, "should have been memory left for 2 medium chunks"); 5124 assert(cm.sum_free_chunks() == 2*MediumChunk, "sizes should add up"); 5125 } 5126 5127 const size_t page_chunks = 4 * (size_t)os::vm_page_size() / BytesPerWord; 5128 // This doesn't work for systems with vm_page_size >= 16K. 5129 if (page_chunks < MediumChunk) { 5130 // 4 pages of VSN is committed, some is used by chunks 5131 ChunkManager cm(false); 5132 VirtualSpaceNode vsn(false, vsn_test_size_bytes); 5133 5134 vsn.initialize(); 5135 vsn.expand_by(page_chunks, page_chunks); 5136 vsn.get_chunk_vs(SmallChunk); 5137 vsn.get_chunk_vs(SpecializedChunk); 5138 vsn.retire(&cm); 5139 5140 // committed - used = words left to retire 5141 const size_t words_left = page_chunks - SmallChunk - SpecializedChunk; 5142 5143 size_t num_medium_chunks, num_small_chunks, num_spec_chunks; 5144 chunk_up(words_left, num_medium_chunks, num_small_chunks, num_spec_chunks); 5145 5146 assert(num_medium_chunks == 0, "should not get any medium chunks"); 5147 assert(cm.sum_free_chunks_count() == (num_small_chunks + num_spec_chunks), "should be space for 3 chunks"); 5148 assert(cm.sum_free_chunks() == words_left, "sizes should add up"); 5149 } 5150 5151 { // Half of VSN is committed, a humongous chunk is used 5152 ChunkManager cm(false); 5153 VirtualSpaceNode vsn(false, vsn_test_size_bytes); 5154 vsn.initialize(); 5155 vsn.expand_by(MediumChunk * 2, MediumChunk * 2); 5156 vsn.get_chunk_vs(MediumChunk + SpecializedChunk); // Humongous chunks will be aligned up to MediumChunk + SpecializedChunk 5157 vsn.retire(&cm); 5158 5159 const size_t words_left = MediumChunk * 2 - (MediumChunk + SpecializedChunk); 5160 size_t num_medium_chunks, num_small_chunks, num_spec_chunks; 5161 chunk_up(words_left, num_medium_chunks, num_small_chunks, num_spec_chunks); 5162 5163 assert(num_medium_chunks == 0, "should not get any medium chunks"); 5164 assert(cm.sum_free_chunks_count() == (num_small_chunks + num_spec_chunks), "should be space for 3 chunks"); 5165 assert(cm.sum_free_chunks() == words_left, "sizes should add up"); 5166 } 5167 5168 } 5169 5170 #define assert_is_available_positive(word_size) \ 5171 assert(vsn.is_available(word_size), \ 5172 #word_size ": " PTR_FORMAT " bytes were not available in " \ 5173 "VirtualSpaceNode [" PTR_FORMAT ", " PTR_FORMAT ")", \ 5174 (uintptr_t)(word_size * BytesPerWord), p2i(vsn.bottom()), p2i(vsn.end())); 5175 5176 #define assert_is_available_negative(word_size) \ 5177 assert(!vsn.is_available(word_size), \ 5178 #word_size ": " PTR_FORMAT " bytes should not be available in " \ 5179 "VirtualSpaceNode [" PTR_FORMAT ", " PTR_FORMAT ")", \ 5180 (uintptr_t)(word_size * BytesPerWord), p2i(vsn.bottom()), p2i(vsn.end())); 5181 5182 static void test_is_available_positive() { 5183 // Reserve some memory. 5184 VirtualSpaceNode vsn(false, os::vm_allocation_granularity()); 5185 assert(vsn.initialize(), "Failed to setup VirtualSpaceNode"); 5186 5187 // Commit some memory. 5188 size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord; 5189 bool expanded = vsn.expand_by(commit_word_size, commit_word_size); 5190 assert(expanded, "Failed to commit"); 5191 5192 // Check that is_available accepts the committed size. 5193 assert_is_available_positive(commit_word_size); 5194 5195 // Check that is_available accepts half the committed size. 5196 size_t expand_word_size = commit_word_size / 2; 5197 assert_is_available_positive(expand_word_size); 5198 } 5199 5200 static void test_is_available_negative() { 5201 // Reserve some memory. 5202 VirtualSpaceNode vsn(false, os::vm_allocation_granularity()); 5203 assert(vsn.initialize(), "Failed to setup VirtualSpaceNode"); 5204 5205 // Commit some memory. 5206 size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord; 5207 bool expanded = vsn.expand_by(commit_word_size, commit_word_size); 5208 assert(expanded, "Failed to commit"); 5209 5210 // Check that is_available doesn't accept a too large size. 5211 size_t two_times_commit_word_size = commit_word_size * 2; 5212 assert_is_available_negative(two_times_commit_word_size); 5213 } 5214 5215 static void test_is_available_overflow() { 5216 // Reserve some memory. 5217 VirtualSpaceNode vsn(false, os::vm_allocation_granularity()); 5218 assert(vsn.initialize(), "Failed to setup VirtualSpaceNode"); 5219 5220 // Commit some memory. 5221 size_t commit_word_size = os::vm_allocation_granularity() / BytesPerWord; 5222 bool expanded = vsn.expand_by(commit_word_size, commit_word_size); 5223 assert(expanded, "Failed to commit"); 5224 5225 // Calculate a size that will overflow the virtual space size. 5226 void* virtual_space_max = (void*)(uintptr_t)-1; 5227 size_t bottom_to_max = pointer_delta(virtual_space_max, vsn.bottom(), 1); 5228 size_t overflow_size = bottom_to_max + BytesPerWord; 5229 size_t overflow_word_size = overflow_size / BytesPerWord; 5230 5231 // Check that is_available can handle the overflow. 5232 assert_is_available_negative(overflow_word_size); 5233 } 5234 5235 static void test_is_available() { 5236 TestVirtualSpaceNodeTest::test_is_available_positive(); 5237 TestVirtualSpaceNodeTest::test_is_available_negative(); 5238 TestVirtualSpaceNodeTest::test_is_available_overflow(); 5239 } 5240 }; 5241 5242 // The following test is placed here instead of a gtest / unittest file 5243 // because the ChunkManager class is only available in this file. 5244 void ChunkManager_test_list_index() { 5245 ChunkManager manager(true); 5246 5247 // Test previous bug where a query for a humongous class metachunk, 5248 // incorrectly matched the non-class medium metachunk size. 5249 { 5250 assert(MediumChunk > ClassMediumChunk, "Precondition for test"); 5251 5252 ChunkIndex index = manager.list_index(MediumChunk); 5253 5254 assert(index == HumongousIndex, 5255 "Requested size is larger than ClassMediumChunk," 5256 " so should return HumongousIndex. Got index: %d", (int)index); 5257 } 5258 5259 // Check the specified sizes as well. 5260 { 5261 ChunkIndex index = manager.list_index(ClassSpecializedChunk); 5262 assert(index == SpecializedIndex, "Wrong index returned. Got index: %d", (int)index); 5263 } 5264 { 5265 ChunkIndex index = manager.list_index(ClassSmallChunk); 5266 assert(index == SmallIndex, "Wrong index returned. Got index: %d", (int)index); 5267 } 5268 { 5269 ChunkIndex index = manager.list_index(ClassMediumChunk); 5270 assert(index == MediumIndex, "Wrong index returned. Got index: %d", (int)index); 5271 } 5272 { 5273 ChunkIndex index = manager.list_index(ClassMediumChunk + 1); 5274 assert(index == HumongousIndex, "Wrong index returned. Got index: %d", (int)index); 5275 } 5276 } 5277 5278 #endif // !PRODUCT 5279 5280 #ifdef ASSERT 5281 5282 // The following test is placed here instead of a gtest / unittest file 5283 // because the ChunkManager class is only available in this file. 5284 class SpaceManagerTest : AllStatic { 5285 friend void SpaceManager_test_adjust_initial_chunk_size(); 5286 5287 static void test_adjust_initial_chunk_size(bool is_class) { 5288 const size_t smallest = SpaceManager::smallest_chunk_size(is_class); 5289 const size_t normal = SpaceManager::small_chunk_size(is_class); 5290 const size_t medium = SpaceManager::medium_chunk_size(is_class); 5291 5292 #define test_adjust_initial_chunk_size(value, expected, is_class_value) \ 5293 do { \ 5294 size_t v = value; \ 5295 size_t e = expected; \ 5296 assert(SpaceManager::adjust_initial_chunk_size(v, (is_class_value)) == e, \ 5297 "Expected: " SIZE_FORMAT " got: " SIZE_FORMAT, e, v); \ 5298 } while (0) 5299 5300 // Smallest (specialized) 5301 test_adjust_initial_chunk_size(1, smallest, is_class); 5302 test_adjust_initial_chunk_size(smallest - 1, smallest, is_class); 5303 test_adjust_initial_chunk_size(smallest, smallest, is_class); 5304 5305 // Small 5306 test_adjust_initial_chunk_size(smallest + 1, normal, is_class); 5307 test_adjust_initial_chunk_size(normal - 1, normal, is_class); 5308 test_adjust_initial_chunk_size(normal, normal, is_class); 5309 5310 // Medium 5311 test_adjust_initial_chunk_size(normal + 1, medium, is_class); 5312 test_adjust_initial_chunk_size(medium - 1, medium, is_class); 5313 test_adjust_initial_chunk_size(medium, medium, is_class); 5314 5315 // Humongous 5316 test_adjust_initial_chunk_size(medium + 1, medium + 1, is_class); 5317 5318 #undef test_adjust_initial_chunk_size 5319 } 5320 5321 static void test_adjust_initial_chunk_size() { 5322 test_adjust_initial_chunk_size(false); 5323 test_adjust_initial_chunk_size(true); 5324 } 5325 }; 5326 5327 void SpaceManager_test_adjust_initial_chunk_size() { 5328 SpaceManagerTest::test_adjust_initial_chunk_size(); 5329 } 5330 5331 #endif // ASSERT 5332 5333 struct chunkmanager_statistics_t { 5334 int num_specialized_chunks; 5335 int num_small_chunks; 5336 int num_medium_chunks; 5337 int num_humongous_chunks; 5338 }; 5339 5340 extern void test_metaspace_retrieve_chunkmanager_statistics(Metaspace::MetadataType mdType, chunkmanager_statistics_t* out) { 5341 ChunkManager* const chunk_manager = Metaspace::get_chunk_manager(mdType); 5342 ChunkManager::ChunkManagerStatistics stat; 5343 chunk_manager->get_statistics(&stat); 5344 out->num_specialized_chunks = (int)stat.num_by_type[SpecializedIndex]; 5345 out->num_small_chunks = (int)stat.num_by_type[SmallIndex]; 5346 out->num_medium_chunks = (int)stat.num_by_type[MediumIndex]; 5347 out->num_humongous_chunks = (int)stat.num_humongous_chunks; 5348 } 5349 5350 struct chunk_geometry_t { 5351 size_t specialized_chunk_word_size; 5352 size_t small_chunk_word_size; 5353 size_t medium_chunk_word_size; 5354 }; 5355 5356 extern void test_metaspace_retrieve_chunk_geometry(Metaspace::MetadataType mdType, chunk_geometry_t* out) { 5357 if (mdType == Metaspace::NonClassType) { 5358 out->specialized_chunk_word_size = SpecializedChunk; 5359 out->small_chunk_word_size = SmallChunk; 5360 out->medium_chunk_word_size = MediumChunk; 5361 } else { 5362 out->specialized_chunk_word_size = ClassSpecializedChunk; 5363 out->small_chunk_word_size = ClassSmallChunk; 5364 out->medium_chunk_word_size = ClassMediumChunk; 5365 } 5366 } 5367