1 /*
2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24 #include "precompiled.hpp"
25
26 #include "logging/log.hpp"
27 #include "logging/logStream.hpp"
28 #include "memory/metaspace/chunkManager.hpp"
29 #include "memory/metaspace/metachunk.hpp"
30 #include "memory/metaspace/metaDebug.hpp"
31 #include "memory/metaspace/metaspaceCommon.hpp"
32 #include "memory/metaspace/spaceManager.hpp"
33 #include "memory/metaspace/virtualSpaceList.hpp"
34 #include "runtime/atomic.hpp"
35 #include "runtime/init.hpp"
36 #include "services/memoryService.hpp"
37 #include "utilities/debug.hpp"
38 #include "utilities/globalDefinitions.hpp"
39
40 namespace metaspace {
41
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::AnonymousMetaspaceType: 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::AnonymousMetaspaceType: 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 anonymous metadata space.
118 // Anonymous metadata space is usually small, with majority within 1K - 2K range and
119 // rarely about 4K (64-bits JVM).
120 // Instead of jumping to SmallChunk after initial chunk exhausted, keeping allocation
121 // from SpecializeChunk up to _anon_or_delegating_metadata_specialize_chunk_limit (4)
122 // reduces space waste from 60+% to around 30%.
123 if ((_space_type == Metaspace::AnonymousMetaspaceType || _space_type == Metaspace::ReflectionMetaspaceType) &&
124 _mdtype == Metaspace::NonClassType &&
125 num_chunks_by_type(SpecializedIndex) < anon_and_delegating_metadata_specialize_chunk_limit &&
126 word_size + Metachunk::overhead() <= SpecializedChunk) {
127 return SpecializedChunk;
128 }
129
130 if (num_chunks_by_type(MediumIndex) == 0 &&
131 num_chunks_by_type(SmallIndex) < small_chunk_limit) {
132 chunk_word_size = (size_t) small_chunk_size();
133 if (word_size + Metachunk::overhead() > small_chunk_size()) {
134 chunk_word_size = medium_chunk_size();
135 }
136 } else {
137 chunk_word_size = medium_chunk_size();
138 }
139
140 // Might still need a humongous chunk. Enforce
141 // humongous allocations sizes to be aligned up to
142 // the smallest chunk size.
143 size_t if_humongous_sized_chunk =
144 align_up(word_size + Metachunk::overhead(),
145 smallest_chunk_size());
146 chunk_word_size =
147 MAX2((size_t) chunk_word_size, if_humongous_sized_chunk);
148
149 assert(!SpaceManager::is_humongous(word_size) ||
150 chunk_word_size == if_humongous_sized_chunk,
151 "Size calculation is wrong, word_size " SIZE_FORMAT
152 " chunk_word_size " SIZE_FORMAT,
153 word_size, chunk_word_size);
154 Log(gc, metaspace, alloc) log;
155 if (log.is_debug() && SpaceManager::is_humongous(word_size)) {
156 log.debug("Metadata humongous allocation:");
157 log.debug(" word_size " PTR_FORMAT, word_size);
158 log.debug(" chunk_word_size " PTR_FORMAT, chunk_word_size);
159 log.debug(" chunk overhead " PTR_FORMAT, Metachunk::overhead());
160 }
161 return chunk_word_size;
162 }
163
164 void SpaceManager::track_metaspace_memory_usage() {
165 if (is_init_completed()) {
166 if (is_class()) {
167 MemoryService::track_compressed_class_memory_usage();
168 }
169 MemoryService::track_metaspace_memory_usage();
170 }
171 }
172
173 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
174 assert_lock_strong(_lock);
175 assert(vs_list()->current_virtual_space() != NULL,
176 "Should have been set");
177 assert(current_chunk() == NULL ||
178 current_chunk()->allocate(word_size) == NULL,
179 "Don't need to expand");
180 MutexLockerEx cl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
181
182 if (log_is_enabled(Trace, gc, metaspace, freelist)) {
183 size_t words_left = 0;
184 size_t words_used = 0;
185 if (current_chunk() != NULL) {
186 words_left = current_chunk()->free_word_size();
187 words_used = current_chunk()->used_word_size();
188 }
189 log_trace(gc, metaspace, freelist)("SpaceManager::grow_and_allocate for " SIZE_FORMAT " words " SIZE_FORMAT " words used " SIZE_FORMAT " words left",
190 word_size, words_used, words_left);
191 }
192
193 // Get another chunk
194 size_t chunk_word_size = calc_chunk_size(word_size);
195 Metachunk* next = get_new_chunk(chunk_word_size);
196
197 MetaWord* mem = NULL;
198
199 // If a chunk was available, add it to the in-use chunk list
200 // and do an allocation from it.
201 if (next != NULL) {
202 // Add to this manager's list of chunks in use.
203 // If the new chunk is humongous, it was created to serve a single large allocation. In that
204 // case it usually makes no sense to make it the current chunk, since the next allocation would
205 // need to allocate a new chunk anyway, while we would now prematurely retire a perfectly
206 // good chunk which could be used for more normal allocations.
207 bool make_current = true;
208 if (next->get_chunk_type() == HumongousIndex &&
209 current_chunk() != NULL) {
210 make_current = false;
211 }
212 add_chunk(next, make_current);
213 mem = next->allocate(word_size);
214 }
215
216 // Track metaspace memory usage statistic.
217 track_metaspace_memory_usage();
218
219 return mem;
220 }
221
222 void SpaceManager::print_on(outputStream* st) const {
223 SpaceManagerStatistics stat;
224 add_to_statistics(&stat); // will lock _lock.
225 stat.print_on(st, 1*K, false);
226 }
227
228 SpaceManager::SpaceManager(Metaspace::MetadataType mdtype,
229 Metaspace::MetaspaceType space_type,//
230 Mutex* lock) :
231 _mdtype(mdtype),
232 _space_type(space_type),
233 _capacity_words(0),
234 _used_words(0),
235 _overhead_words(0),
236 _block_freelists(NULL),
237 _lock(lock),
238 _chunk_list(NULL),
239 _current_chunk(NULL)
240 {
241 Metadebug::init_allocation_fail_alot_count();
242 memset(_num_chunks_by_type, 0, sizeof(_num_chunks_by_type));
243 log_trace(gc, metaspace, freelist)("SpaceManager(): " PTR_FORMAT, p2i(this));
244 }
245
246 void SpaceManager::account_for_new_chunk(const Metachunk* new_chunk) {
247
248 assert_lock_strong(MetaspaceExpand_lock);
249
250 _capacity_words += new_chunk->word_size();
251 _overhead_words += Metachunk::overhead();
252 DEBUG_ONLY(new_chunk->verify());
253 _num_chunks_by_type[new_chunk->get_chunk_type()] ++;
254
255 // Adjust global counters:
256 MetaspaceUtils::inc_capacity(mdtype(), new_chunk->word_size());
257 MetaspaceUtils::inc_overhead(mdtype(), Metachunk::overhead());
258 }
259
260 void SpaceManager::account_for_allocation(size_t words) {
261 // Note: we should be locked with the ClassloaderData-specific metaspace lock.
262 // We may or may not be locked with the global metaspace expansion lock.
263 assert_lock_strong(lock());
264
265 // Add to the per SpaceManager totals. This can be done non-atomically.
266 _used_words += words;
267
268 // Adjust global counters. This will be done atomically.
269 MetaspaceUtils::inc_used(mdtype(), words);
270 }
271
272 void SpaceManager::account_for_spacemanager_death() {
273
274 assert_lock_strong(MetaspaceExpand_lock);
275
276 MetaspaceUtils::dec_capacity(mdtype(), _capacity_words);
277 MetaspaceUtils::dec_overhead(mdtype(), _overhead_words);
278 MetaspaceUtils::dec_used(mdtype(), _used_words);
279 }
280
281 SpaceManager::~SpaceManager() {
282
283 // This call this->_lock which can't be done while holding MetaspaceExpand_lock
284 DEBUG_ONLY(verify_metrics());
285
286 MutexLockerEx fcl(MetaspaceExpand_lock,
287 Mutex::_no_safepoint_check_flag);
288
289 chunk_manager()->slow_locked_verify();
290
291 account_for_spacemanager_death();
292
293 Log(gc, metaspace, freelist) log;
294 if (log.is_trace()) {
295 log.trace("~SpaceManager(): " PTR_FORMAT, p2i(this));
296 ResourceMark rm;
297 LogStream ls(log.trace());
298 locked_print_chunks_in_use_on(&ls);
299 if (block_freelists() != NULL) {
300 block_freelists()->print_on(&ls);
301 }
302 }
303
304 // Add all the chunks in use by this space manager
305 // to the global list of free chunks.
306
307 // Follow each list of chunks-in-use and add them to the
308 // free lists. Each list is NULL terminated.
309 chunk_manager()->return_chunk_list(chunk_list());
310 #ifdef ASSERT
311 _chunk_list = NULL;
312 _current_chunk = NULL;
313 #endif
314
315 chunk_manager()->slow_locked_verify();
316
317 if (_block_freelists != NULL) {
318 delete _block_freelists;
319 }
320 }
321
322 void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
323 assert_lock_strong(lock());
324 // Allocations and deallocations are in raw_word_size
325 size_t raw_word_size = get_allocation_word_size(word_size);
326 // Lazily create a block_freelist
327 if (block_freelists() == NULL) {
328 _block_freelists = new BlockFreelist();
329 }
330 block_freelists()->return_block(p, raw_word_size);
331 DEBUG_ONLY(Atomic::inc(&(g_internal_statistics.num_deallocs)));
332 }
333
334 // Adds a chunk to the list of chunks in use.
335 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
336
337 assert_lock_strong(_lock);
338 assert(new_chunk != NULL, "Should not be NULL");
339 assert(new_chunk->next() == NULL, "Should not be on a list");
340
341 new_chunk->reset_empty();
342
343 // Find the correct list and and set the current
344 // chunk for that list.
345 ChunkIndex index = chunk_manager()->list_index(new_chunk->word_size());
346
347 if (make_current) {
348 // If we are to make the chunk current, retire the old current chunk and replace
349 // it with the new chunk.
350 retire_current_chunk();
351 set_current_chunk(new_chunk);
352 }
353
354 // Add the new chunk at the head of its respective chunk list.
355 new_chunk->set_next(_chunk_list);
356 _chunk_list = new_chunk;
357
358 // Adjust counters.
359 account_for_new_chunk(new_chunk);
360
361 assert(new_chunk->is_empty(), "Not ready for reuse");
362 Log(gc, metaspace, freelist) log;
363 if (log.is_trace()) {
364 log.trace("SpaceManager::added chunk: ");
365 ResourceMark rm;
366 LogStream ls(log.trace());
367 new_chunk->print_on(&ls);
368 chunk_manager()->locked_print_free_chunks(&ls);
369 }
370 }
371
372 void SpaceManager::retire_current_chunk() {
373 if (current_chunk() != NULL) {
374 size_t remaining_words = current_chunk()->free_word_size();
375 if (remaining_words >= SmallBlocks::small_block_min_size()) {
376 MetaWord* ptr = current_chunk()->allocate(remaining_words);
377 deallocate(ptr, remaining_words);
378 account_for_allocation(remaining_words);
379 }
380 }
381 }
382
383 Metachunk* SpaceManager::get_new_chunk(size_t chunk_word_size) {
384 // Get a chunk from the chunk freelist
385 Metachunk* next = chunk_manager()->chunk_freelist_allocate(chunk_word_size);
386
387 if (next == NULL) {
388 next = vs_list()->get_new_chunk(chunk_word_size,
389 medium_chunk_bunch());
390 }
391
392 Log(gc, metaspace, alloc) log;
393 if (log.is_debug() && next != NULL &&
394 SpaceManager::is_humongous(next->word_size())) {
395 log.debug(" new humongous chunk word size " PTR_FORMAT, next->word_size());
396 }
397
398 return next;
399 }
400
401 MetaWord* SpaceManager::allocate(size_t word_size) {
402 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
403 size_t raw_word_size = get_allocation_word_size(word_size);
404 BlockFreelist* fl = block_freelists();
405 MetaWord* p = NULL;
406
407 DEBUG_ONLY(if (VerifyMetaspace) verify_metrics_locked());
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 return p;
425 }
426
427 // Returns the address of spaced allocated for "word_size".
428 // This methods does not know about blocks (Metablocks)
429 MetaWord* SpaceManager::allocate_work(size_t word_size) {
430 assert_lock_strong(lock());
431 #ifdef ASSERT
432 if (Metadebug::test_metadata_failure()) {
433 return NULL;
434 }
435 #endif
436 // Is there space in the current chunk?
437 MetaWord* result = NULL;
438
439 if (current_chunk() != NULL) {
440 result = current_chunk()->allocate(word_size);
441 }
442
443 if (result == NULL) {
444 result = grow_and_allocate(word_size);
445 }
446
447 if (result != NULL) {
448 account_for_allocation(word_size);
449 }
450
451 return result;
452 }
453
454 void SpaceManager::verify() {
455 Metachunk* curr = chunk_list();
456 while (curr != NULL) {
457 DEBUG_ONLY(do_verify_chunk(curr);)
458 assert(curr->is_tagged_free() == false, "Chunk should be tagged as in use.");
459 curr = curr->next();
460 }
461 }
462
463 void SpaceManager::verify_chunk_size(Metachunk* chunk) {
464 assert(is_humongous(chunk->word_size()) ||
465 chunk->word_size() == medium_chunk_size() ||
466 chunk->word_size() == small_chunk_size() ||
467 chunk->word_size() == specialized_chunk_size(),
468 "Chunk size is wrong");
469 return;
470 }
471
472 void SpaceManager::add_to_statistics_locked(SpaceManagerStatistics* out) const {
473 assert_lock_strong(lock());
474 Metachunk* chunk = chunk_list();
475 while (chunk != NULL) {
476 UsedChunksStatistics& chunk_stat = out->chunk_stats(chunk->get_chunk_type());
477 chunk_stat.add_num(1);
478 chunk_stat.add_cap(chunk->word_size());
479 chunk_stat.add_overhead(Metachunk::overhead());
480 chunk_stat.add_used(chunk->used_word_size() - Metachunk::overhead());
481 if (chunk != current_chunk()) {
482 chunk_stat.add_waste(chunk->free_word_size());
483 } else {
484 chunk_stat.add_free(chunk->free_word_size());
485 }
486 chunk = chunk->next();
487 }
488 if (block_freelists() != NULL) {
489 out->add_free_blocks_info(block_freelists()->num_blocks(), block_freelists()->total_size());
490 }
491 }
492
493 void SpaceManager::add_to_statistics(SpaceManagerStatistics* out) const {
494 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
495 add_to_statistics_locked(out);
496 }
497
498 #ifdef ASSERT
499 void SpaceManager::verify_metrics_locked() const {
500 assert_lock_strong(lock());
501
502 SpaceManagerStatistics stat;
503 add_to_statistics_locked(&stat);
504
505 UsedChunksStatistics chunk_stats = stat.totals();
506
507 DEBUG_ONLY(chunk_stats.check_sanity());
508
509 assert_counter(_capacity_words, chunk_stats.cap(), "SpaceManager::_capacity_words");
510 assert_counter(_used_words, chunk_stats.used(), "SpaceManager::_used_words");
511 assert_counter(_overhead_words, chunk_stats.overhead(), "SpaceManager::_overhead_words");
512 }
513
514 void SpaceManager::verify_metrics() const {
515 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
516 verify_metrics_locked();
517 }
518 #endif // ASSERT
519
520
521 } // namespace metaspace
522