1 /*
2 * Copyright (c) 2018, 2020, 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.
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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.
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23 */
24 #include "precompiled.hpp"
25
26 #include "logging/log.hpp"
27 #include "logging/logStream.hpp"
28 #include "memory/metaspace/chunkManager.hpp"
29 #include "memory/metaspace/metachunk.hpp"
30 #include "memory/metaspace/metaDebug.hpp"
31 #include "memory/metaspace/metaspaceCommon.hpp"
32 #include "memory/metaspace/spaceManager.hpp"
33 #include "memory/metaspace/virtualSpaceList.hpp"
34 #include "runtime/atomic.hpp"
35 #include "runtime/init.hpp"
36 #include "services/memoryService.hpp"
37 #include "utilities/debug.hpp"
38 #include "utilities/globalDefinitions.hpp"
39
40 namespace metaspace {
41
42 #define assert_counter(expected_value, real_value, msg) \
43 assert( (expected_value) == (real_value), \
44 "Counter mismatch (%s): expected " SIZE_FORMAT \
45 ", but got: " SIZE_FORMAT ".", msg, expected_value, \
46 real_value);
47
48 // SpaceManager methods
49
50 size_t SpaceManager::adjust_initial_chunk_size(size_t requested, bool is_class_space) {
51 size_t chunk_sizes[] = {
52 specialized_chunk_size(is_class_space),
53 small_chunk_size(is_class_space),
54 medium_chunk_size(is_class_space)
55 };
56
57 // Adjust up to one of the fixed chunk sizes ...
58 for (size_t i = 0; i < ARRAY_SIZE(chunk_sizes); i++) {
59 if (requested <= chunk_sizes[i]) {
60 return chunk_sizes[i];
61 }
62 }
63
64 // ... or return the size as a humongous chunk.
65 return requested;
66 }
67
68 size_t SpaceManager::adjust_initial_chunk_size(size_t requested) const {
69 return adjust_initial_chunk_size(requested, is_class());
70 }
71
72 size_t SpaceManager::get_initial_chunk_size(Metaspace::MetaspaceType type) const {
73 size_t requested;
74
75 if (is_class()) {
76 switch (type) {
77 case Metaspace::BootMetaspaceType: requested = Metaspace::first_class_chunk_word_size(); break;
78 case Metaspace::ClassMirrorHolderMetaspaceType: requested = ClassSpecializedChunk; break;
79 case Metaspace::ReflectionMetaspaceType: requested = ClassSpecializedChunk; break;
80 default: requested = ClassSmallChunk; break;
81 }
82 } else {
83 switch (type) {
84 case Metaspace::BootMetaspaceType: requested = Metaspace::first_chunk_word_size(); break;
85 case Metaspace::ClassMirrorHolderMetaspaceType: requested = SpecializedChunk; break;
86 case Metaspace::ReflectionMetaspaceType: requested = SpecializedChunk; break;
87 default: requested = SmallChunk; break;
88 }
89 }
90
91 // Adjust to one of the fixed chunk sizes (unless humongous)
92 const size_t adjusted = adjust_initial_chunk_size(requested);
93
94 assert(adjusted != 0, "Incorrect initial chunk size. Requested: "
95 SIZE_FORMAT " adjusted: " SIZE_FORMAT, requested, adjusted);
96
97 return adjusted;
98 }
99
100 void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const {
101
102 for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
103 st->print("SpaceManager: " UINTX_FORMAT " %s chunks.",
104 num_chunks_by_type(i), chunk_size_name(i));
105 }
106
107 chunk_manager()->locked_print_free_chunks(st);
108 }
109
110 size_t SpaceManager::calc_chunk_size(size_t word_size) {
111
112 // Decide between a small chunk and a medium chunk. Up to
113 // _small_chunk_limit small chunks can be allocated.
114 // After that a medium chunk is preferred.
115 size_t chunk_word_size;
116
117 // Special case for hidden metadata space.
118 // ClassMirrorHolder metadata space is usually small since it is used for
119 // class loader data's whose life cycle is governed by one class such as a
120 // non-strong hidden class or unsafe anonymous class. The majority within 1K - 2K range and
121 // rarely about 4K (64-bits JVM).
122 // Instead of jumping to SmallChunk after initial chunk exhausted, keeping allocation
123 // from SpecializeChunk up to _anon_or_delegating_metadata_specialize_chunk_limit (4)
124 // reduces space waste from 60+% to around 30%.
125 if ((_space_type == Metaspace::ClassMirrorHolderMetaspaceType || _space_type == Metaspace::ReflectionMetaspaceType) &&
126 _mdtype == Metaspace::NonClassType &&
127 num_chunks_by_type(SpecializedIndex) < anon_and_delegating_metadata_specialize_chunk_limit &&
128 word_size + Metachunk::overhead() <= SpecializedChunk) {
129 return SpecializedChunk;
130 }
131
132 if (num_chunks_by_type(MediumIndex) == 0 &&
133 num_chunks_by_type(SmallIndex) < small_chunk_limit) {
134 chunk_word_size = (size_t) small_chunk_size();
135 if (word_size + Metachunk::overhead() > small_chunk_size()) {
136 chunk_word_size = medium_chunk_size();
137 }
138 } else {
139 chunk_word_size = medium_chunk_size();
140 }
141
142 // Might still need a humongous chunk. Enforce
143 // humongous allocations sizes to be aligned up to
144 // the smallest chunk size.
145 size_t if_humongous_sized_chunk =
146 align_up(word_size + Metachunk::overhead(),
147 smallest_chunk_size());
148 chunk_word_size =
149 MAX2((size_t) chunk_word_size, if_humongous_sized_chunk);
150
151 assert(!SpaceManager::is_humongous(word_size) ||
152 chunk_word_size == if_humongous_sized_chunk,
153 "Size calculation is wrong, word_size " SIZE_FORMAT
154 " chunk_word_size " SIZE_FORMAT,
155 word_size, chunk_word_size);
156 Log(gc, metaspace, alloc) log;
157 if (log.is_trace() && SpaceManager::is_humongous(word_size)) {
158 log.trace("Metadata humongous allocation:");
159 log.trace(" word_size " PTR_FORMAT, word_size);
160 log.trace(" chunk_word_size " PTR_FORMAT, chunk_word_size);
161 log.trace(" chunk overhead " PTR_FORMAT, Metachunk::overhead());
162 }
163 return chunk_word_size;
164 }
165
166 void SpaceManager::track_metaspace_memory_usage() {
167 if (is_init_completed()) {
168 if (is_class()) {
169 MemoryService::track_compressed_class_memory_usage();
170 }
171 MemoryService::track_metaspace_memory_usage();
172 }
173 }
174
175 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
176 assert_lock_strong(_lock);
177 assert(vs_list()->current_virtual_space() != NULL,
178 "Should have been set");
179 assert(current_chunk() == NULL ||
180 current_chunk()->allocate(word_size) == NULL,
181 "Don't need to expand");
182 MutexLocker cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
183
184 if (log_is_enabled(Trace, gc, metaspace, freelist)) {
185 size_t words_left = 0;
186 size_t words_used = 0;
187 if (current_chunk() != NULL) {
188 words_left = current_chunk()->free_word_size();
189 words_used = current_chunk()->used_word_size();
190 }
191 log_trace(gc, metaspace, freelist)("SpaceManager::grow_and_allocate for " SIZE_FORMAT " words " SIZE_FORMAT " words used " SIZE_FORMAT " words left",
192 word_size, words_used, words_left);
193 }
194
195 // Get another chunk
196 size_t chunk_word_size = calc_chunk_size(word_size);
197 Metachunk* next = get_new_chunk(chunk_word_size);
198
199 MetaWord* mem = NULL;
200
201 // If a chunk was available, add it to the in-use chunk list
202 // and do an allocation from it.
203 if (next != NULL) {
204 // Add to this manager's list of chunks in use.
205 // If the new chunk is humongous, it was created to serve a single large allocation. In that
206 // case it usually makes no sense to make it the current chunk, since the next allocation would
207 // need to allocate a new chunk anyway, while we would now prematurely retire a perfectly
208 // good chunk which could be used for more normal allocations.
209 bool make_current = true;
210 if (next->get_chunk_type() == HumongousIndex &&
211 current_chunk() != NULL) {
212 make_current = false;
213 }
214 add_chunk(next, make_current);
215 mem = next->allocate(word_size);
216 }
217
218 // Track metaspace memory usage statistic.
219 track_metaspace_memory_usage();
220
221 return mem;
222 }
223
224 void SpaceManager::print_on(outputStream* st) const {
225 SpaceManagerStatistics stat;
226 add_to_statistics(&stat); // will lock _lock.
227 stat.print_on(st, 1*K, false);
228 }
229
230 SpaceManager::SpaceManager(Metaspace::MetadataType mdtype,
231 Metaspace::MetaspaceType space_type,//
232 Mutex* lock) :
233 _lock(lock),
234 _mdtype(mdtype),
235 _space_type(space_type),
236 _chunk_list(NULL),
237 _current_chunk(NULL),
238 _overhead_words(0),
239 _capacity_words(0),
240 _used_words(0),
241 _block_freelists(NULL) {
242 Metadebug::init_allocation_fail_alot_count();
243 memset(_num_chunks_by_type, 0, sizeof(_num_chunks_by_type));
244 log_trace(gc, metaspace, freelist)("SpaceManager(): " PTR_FORMAT, p2i(this));
245 }
246
247 void SpaceManager::account_for_new_chunk(const Metachunk* new_chunk) {
248
249 assert_lock_strong(MetaspaceExpand_lock);
250
251 _capacity_words += new_chunk->word_size();
252 _overhead_words += Metachunk::overhead();
253 DEBUG_ONLY(new_chunk->verify());
254 _num_chunks_by_type[new_chunk->get_chunk_type()] ++;
255
256 // Adjust global counters:
257 MetaspaceUtils::inc_capacity(mdtype(), new_chunk->word_size());
258 MetaspaceUtils::inc_overhead(mdtype(), Metachunk::overhead());
259 }
260
261 void SpaceManager::account_for_allocation(size_t words) {
262 // Note: we should be locked with the ClassloaderData-specific metaspace lock.
263 // We may or may not be locked with the global metaspace expansion lock.
264 assert_lock_strong(lock());
265
266 // Add to the per SpaceManager totals. This can be done non-atomically.
267 _used_words += words;
268
269 // Adjust global counters. This will be done atomically.
270 MetaspaceUtils::inc_used(mdtype(), words);
271 }
272
273 void SpaceManager::account_for_spacemanager_death() {
274
275 assert_lock_strong(MetaspaceExpand_lock);
276
277 MetaspaceUtils::dec_capacity(mdtype(), _capacity_words);
278 MetaspaceUtils::dec_overhead(mdtype(), _overhead_words);
279 MetaspaceUtils::dec_used(mdtype(), _used_words);
280 }
281
282 SpaceManager::~SpaceManager() {
283
284 // This call this->_lock which can't be done while holding MetaspaceExpand_lock
285 DEBUG_ONLY(verify_metrics());
286
287 MutexLocker fcl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
288
289 account_for_spacemanager_death();
290
291 Log(gc, metaspace, freelist) log;
292 if (log.is_trace()) {
293 log.trace("~SpaceManager(): " PTR_FORMAT, p2i(this));
294 ResourceMark rm;
295 LogStream ls(log.trace());
296 locked_print_chunks_in_use_on(&ls);
297 if (block_freelists() != NULL) {
298 block_freelists()->print_on(&ls);
299 }
300 }
301
302 // Add all the chunks in use by this space manager
303 // to the global list of free chunks.
304
305 // Follow each list of chunks-in-use and add them to the
306 // free lists. Each list is NULL terminated.
307 chunk_manager()->return_chunk_list(chunk_list());
308 #ifdef ASSERT
309 _chunk_list = NULL;
310 _current_chunk = NULL;
311 #endif
312
313 #ifdef ASSERT
314 EVERY_NTH(VerifyMetaspaceInterval)
315 chunk_manager()->locked_verify(true);
316 END_EVERY_NTH
317 #endif
318
319 if (_block_freelists != NULL) {
320 delete _block_freelists;
321 }
322 }
323
324 void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
325 assert_lock_strong(lock());
326 // Allocations and deallocations are in raw_word_size
327 size_t raw_word_size = get_allocation_word_size(word_size);
328 // Lazily create a block_freelist
329 if (block_freelists() == NULL) {
330 _block_freelists = new BlockFreelist();
331 }
332 block_freelists()->return_block(p, raw_word_size);
333 DEBUG_ONLY(Atomic::inc(&(g_internal_statistics.num_deallocs)));
334 }
335
336 // Adds a chunk to the list of chunks in use.
337 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
338
339 assert_lock_strong(_lock);
340 assert(new_chunk != NULL, "Should not be NULL");
341 assert(new_chunk->next() == NULL, "Should not be on a list");
342
343 new_chunk->reset_empty();
344
345 // Find the correct list and and set the current
346 // chunk for that list.
347 ChunkIndex index = chunk_manager()->list_index(new_chunk->word_size());
348
349 if (make_current) {
350 // If we are to make the chunk current, retire the old current chunk and replace
351 // it with the new chunk.
352 retire_current_chunk();
353 set_current_chunk(new_chunk);
354 }
355
356 // Add the new chunk at the head of its respective chunk list.
357 new_chunk->set_next(_chunk_list);
358 _chunk_list = new_chunk;
359
360 // Adjust counters.
361 account_for_new_chunk(new_chunk);
362
363 assert(new_chunk->is_empty(), "Not ready for reuse");
364 Log(gc, metaspace, freelist) log;
365 if (log.is_trace()) {
366 log.trace("SpaceManager::added chunk: ");
367 ResourceMark rm;
368 LogStream ls(log.trace());
369 new_chunk->print_on(&ls);
370 chunk_manager()->locked_print_free_chunks(&ls);
371 }
372 }
373
374 void SpaceManager::retire_current_chunk() {
375 if (current_chunk() != NULL) {
376 size_t remaining_words = current_chunk()->free_word_size();
377 if (remaining_words >= SmallBlocks::small_block_min_size()) {
378 MetaWord* ptr = current_chunk()->allocate(remaining_words);
379 deallocate(ptr, remaining_words);
380 account_for_allocation(remaining_words);
381 }
382 }
383 }
384
385 Metachunk* SpaceManager::get_new_chunk(size_t chunk_word_size) {
386 // Get a chunk from the chunk freelist
387 Metachunk* next = chunk_manager()->chunk_freelist_allocate(chunk_word_size);
388
389 if (next == NULL) {
390 next = vs_list()->get_new_chunk(chunk_word_size,
391 medium_chunk_bunch());
392 }
393
394 Log(gc, metaspace, alloc) log;
395 if (log.is_trace() && next != NULL &&
396 SpaceManager::is_humongous(next->word_size())) {
397 log.trace(" new humongous chunk word size " PTR_FORMAT, next->word_size());
398 }
399
400 return next;
401 }
402
403 MetaWord* SpaceManager::allocate(size_t word_size) {
404 MutexLocker cl(lock(), Mutex::_no_safepoint_check_flag);
405 size_t raw_word_size = get_allocation_word_size(word_size);
406 BlockFreelist* fl = block_freelists();
407 MetaWord* p = NULL;
408
409 // Allocation from the dictionary is expensive in the sense that
410 // the dictionary has to be searched for a size. Don't allocate
411 // from the dictionary until it starts to get fat. Is this
412 // a reasonable policy? Maybe an skinny dictionary is fast enough
413 // for allocations. Do some profiling. JJJ
414 if (fl != NULL && fl->total_size() > allocation_from_dictionary_limit) {
415 p = fl->get_block(raw_word_size);
416 if (p != NULL) {
417 DEBUG_ONLY(Atomic::inc(&g_internal_statistics.num_allocs_from_deallocated_blocks));
418 }
419 }
420 if (p == NULL) {
421 p = allocate_work(raw_word_size);
422 }
423
424 #ifdef ASSERT
425 EVERY_NTH(VerifyMetaspaceInterval)
426 verify_metrics_locked();
427 END_EVERY_NTH
428 #endif
429
430 return p;
431 }
432
433 // Returns the address of spaced allocated for "word_size".
434 // This methods does not know about blocks (Metablocks)
435 MetaWord* SpaceManager::allocate_work(size_t word_size) {
436 assert_lock_strong(lock());
437 #ifdef ASSERT
438 if (Metadebug::test_metadata_failure()) {
439 return NULL;
440 }
441 #endif
442 // Is there space in the current chunk?
443 MetaWord* result = NULL;
444
445 if (current_chunk() != NULL) {
446 result = current_chunk()->allocate(word_size);
447 }
448
449 if (result == NULL) {
450 result = grow_and_allocate(word_size);
451 }
452
453 if (result != NULL) {
454 account_for_allocation(word_size);
455 }
456
457 return result;
458 }
459
460 void SpaceManager::verify() {
461 Metachunk* curr = chunk_list();
462 while (curr != NULL) {
463 DEBUG_ONLY(do_verify_chunk(curr);)
464 assert(curr->is_tagged_free() == false, "Chunk should be tagged as in use.");
465 curr = curr->next();
466 }
467 }
468
469 void SpaceManager::verify_chunk_size(Metachunk* chunk) {
470 assert(is_humongous(chunk->word_size()) ||
471 chunk->word_size() == medium_chunk_size() ||
472 chunk->word_size() == small_chunk_size() ||
473 chunk->word_size() == specialized_chunk_size(),
474 "Chunk size is wrong");
475 return;
476 }
477
478 void SpaceManager::add_to_statistics_locked(SpaceManagerStatistics* out) const {
479 assert_lock_strong(lock());
480 Metachunk* chunk = chunk_list();
481 while (chunk != NULL) {
482 UsedChunksStatistics& chunk_stat = out->chunk_stats(chunk->get_chunk_type());
483 chunk_stat.add_num(1);
484 chunk_stat.add_cap(chunk->word_size());
485 chunk_stat.add_overhead(Metachunk::overhead());
486 chunk_stat.add_used(chunk->used_word_size() - Metachunk::overhead());
487 if (chunk != current_chunk()) {
488 chunk_stat.add_waste(chunk->free_word_size());
489 } else {
490 chunk_stat.add_free(chunk->free_word_size());
491 }
492 chunk = chunk->next();
493 }
494 if (block_freelists() != NULL) {
495 out->add_free_blocks_info(block_freelists()->num_blocks(), block_freelists()->total_size());
496 }
497 }
498
499 void SpaceManager::add_to_statistics(SpaceManagerStatistics* out) const {
500 MutexLocker cl(lock(), Mutex::_no_safepoint_check_flag);
501 add_to_statistics_locked(out);
502 }
503
504 #ifdef ASSERT
505 void SpaceManager::verify_metrics_locked() const {
506 assert_lock_strong(lock());
507
508 SpaceManagerStatistics stat;
509 add_to_statistics_locked(&stat);
510
511 UsedChunksStatistics chunk_stats = stat.totals();
512
513 DEBUG_ONLY(chunk_stats.check_sanity());
514
515 assert_counter(_capacity_words, chunk_stats.cap(), "SpaceManager::_capacity_words");
516 assert_counter(_used_words, chunk_stats.used(), "SpaceManager::_used_words");
517 assert_counter(_overhead_words, chunk_stats.overhead(), "SpaceManager::_overhead_words");
518 }
519
520 void SpaceManager::verify_metrics() const {
521 MutexLocker cl(lock(), Mutex::_no_safepoint_check_flag);
522 verify_metrics_locked();
523 }
524 #endif // ASSERT
525
526
527 } // namespace metaspace
528