1 /*
2 * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2018, 2021 SAP SE. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "gc/shared/gc_globals.hpp"
28 #include "logging/log.hpp"
29 #include "memory/metaspace.hpp"
30 #include "memory/metaspace/chunkHeaderPool.hpp"
31 #include "memory/metaspace/chunklevel.hpp"
32 #include "memory/metaspace/commitLimiter.hpp"
33 #include "memory/metaspace/counters.hpp"
34 #include "memory/metaspace/freeChunkList.hpp"
35 #include "memory/metaspace/internalStats.hpp"
36 #include "memory/metaspace/metachunk.hpp"
37 #include "memory/metaspace/metaspaceCommon.hpp"
38 #include "memory/metaspace/metaspaceSettings.hpp"
39 #include "memory/metaspace/rootChunkArea.hpp"
40 #include "memory/metaspace/runningCounters.hpp"
41 #include "memory/metaspace/virtualSpaceNode.hpp"
42 #include "runtime/globals.hpp"
43 #include "runtime/mutexLocker.hpp"
44 #include "runtime/os.hpp"
45 #include "sanitizers/address.hpp"
46 #include "sanitizers/leak.hpp"
47 #include "services/memTracker.hpp"
48 #include "utilities/align.hpp"
49 #include "utilities/debug.hpp"
50 #include "utilities/globalDefinitions.hpp"
51 #include "utilities/ostream.hpp"
52
53 namespace metaspace {
54
55 #define LOGFMT "VsListNode @" PTR_FORMAT " base " PTR_FORMAT " "
56 #define LOGFMT_ARGS p2i(this), p2i(_base)
57
58 #ifdef ASSERT
59 void check_pointer_is_aligned_to_commit_granule(const MetaWord* p) {
60 assert(is_aligned(p, Settings::commit_granule_bytes()),
61 "Pointer not aligned to commit granule size: " PTR_FORMAT ".",
62 p2i(p));
63 }
64 void check_word_size_is_aligned_to_commit_granule(size_t word_size) {
65 assert(is_aligned(word_size, Settings::commit_granule_words()),
66 "Not aligned to commit granule size: " SIZE_FORMAT ".", word_size);
67 }
68 #endif
69
70 // Given an address range, ensure it is committed.
71 //
72 // The range has to be aligned to granule size.
73 //
74 // Function will:
75 // - check how many granules in that region are uncommitted; If all are committed, it
76 // returns true immediately.
77 // - check if committing those uncommitted granules would bring us over the commit limit
78 // (GC threshold, MaxMetaspaceSize). If true, it returns false.
79 // - commit the memory.
80 // - mark the range as committed in the commit mask
81 //
82 // Returns true if success, false if it did hit a commit limit.
83 bool VirtualSpaceNode::commit_range(MetaWord* p, size_t word_size) {
84 DEBUG_ONLY(check_pointer_is_aligned_to_commit_granule(p);)
85 DEBUG_ONLY(check_word_size_is_aligned_to_commit_granule(word_size);)
86 assert_lock_strong(Metaspace_lock);
87
88 // First calculate how large the committed regions in this range are
89 const size_t committed_words_in_range = _commit_mask.get_committed_size_in_range(p, word_size);
90 DEBUG_ONLY(check_word_size_is_aligned_to_commit_granule(committed_words_in_range);)
91
92 // By how much words we would increase commit charge
93 // were we to commit the given address range completely.
94 const size_t commit_increase_words = word_size - committed_words_in_range;
95
96 UL2(debug, "committing range " PTR_FORMAT ".." PTR_FORMAT "(" SIZE_FORMAT " words)",
97 p2i(p), p2i(p + word_size), word_size);
98
99 if (commit_increase_words == 0) {
100 UL(debug, "... already fully committed.");
101 return true; // Already fully committed, nothing to do.
102 }
103
104 // Before committing any more memory, check limits.
105 if (_commit_limiter->possible_expansion_words() < commit_increase_words) {
106 UL(debug, "... cannot commit (limit).");
107 return false;
108 }
109
110 // Commit...
111 if (os::commit_memory((char*)p, word_size * BytesPerWord, false) == false) {
112 vm_exit_out_of_memory(word_size * BytesPerWord, OOM_MMAP_ERROR, "Failed to commit metaspace.");
113 }
114
115 if (AlwaysPreTouch) {
116 os::pretouch_memory(p, p + word_size);
117 }
118
119 UL2(debug, "... committed " SIZE_FORMAT " additional words.", commit_increase_words);
120
121 // ... tell commit limiter...
122 _commit_limiter->increase_committed(commit_increase_words);
123
124 // ... update counters in containing vslist ...
125 _total_committed_words_counter->increment_by(commit_increase_words);
126
127 // ... and update the commit mask.
128 _commit_mask.mark_range_as_committed(p, word_size);
129
130 #ifdef ASSERT
131 // The commit boundary maintained in the CommitLimiter should be equal the sum of committed words
132 // in both class and non-class vslist (outside gtests).
133 if (_commit_limiter == CommitLimiter::globalLimiter()) {
134 assert(_commit_limiter->committed_words() == RunningCounters::committed_words(), "counter mismatch");
135 }
136 #endif
137
138 InternalStats::inc_num_space_committed();
139 return true;
140 }
141
142 // Given an address range, ensure it is committed.
143 //
144 // The range does not have to be aligned to granule size. However, the function will always commit
145 // whole granules.
146 //
147 // Function will:
148 // - check how many granules in that region are uncommitted; If all are committed, it
149 // returns true immediately.
150 // - check if committing those uncommitted granules would bring us over the commit limit
151 // (GC threshold, MaxMetaspaceSize). If true, it returns false.
152 // - commit the memory.
153 // - mark the range as committed in the commit mask
154 //
155 // !! Careful:
156 // calling ensure_range_is_committed on a range which contains both committed and uncommitted
157 // areas will commit the whole area, thus erase the content in the existing committed parts.
158 // Make sure you never call this on an address range containing live data. !!
159 //
160 // Returns true if success, false if it did hit a commit limit.
161 bool VirtualSpaceNode::ensure_range_is_committed(MetaWord* p, size_t word_size) {
162 assert_lock_strong(Metaspace_lock);
163 assert(p != nullptr && word_size > 0, "Sanity");
164 MetaWord* p_start = align_down(p, Settings::commit_granule_bytes());
165 MetaWord* p_end = align_up(p + word_size, Settings::commit_granule_bytes());
166 return commit_range(p_start, p_end - p_start);
167 }
168
169 // Given an address range (which has to be aligned to commit granule size):
170 // - uncommit it
171 // - mark it as uncommitted in the commit mask
172 void VirtualSpaceNode::uncommit_range(MetaWord* p, size_t word_size) {
173 DEBUG_ONLY(check_pointer_is_aligned_to_commit_granule(p);)
174 DEBUG_ONLY(check_word_size_is_aligned_to_commit_granule(word_size);)
175 assert_lock_strong(Metaspace_lock);
176
177 // First calculate how large the committed regions in this range are
178 const size_t committed_words_in_range = _commit_mask.get_committed_size_in_range(p, word_size);
179 DEBUG_ONLY(check_word_size_is_aligned_to_commit_granule(committed_words_in_range);)
180
181 UL2(debug, "uncommitting range " PTR_FORMAT ".." PTR_FORMAT "(" SIZE_FORMAT " words)",
182 p2i(p), p2i(p + word_size), word_size);
183
184 if (committed_words_in_range == 0) {
185 UL(debug, "... already fully uncommitted.");
186 return; // Already fully uncommitted, nothing to do.
187 }
188
189 // Uncommit...
190 if (os::uncommit_memory((char*)p, word_size * BytesPerWord) == false) {
191 // Note: this can actually happen, since uncommit may increase the number of mappings.
192 fatal("Failed to uncommit metaspace.");
193 }
194
195 UL2(debug, "... uncommitted " SIZE_FORMAT " words.", committed_words_in_range);
196
197 // ... tell commit limiter...
198 _commit_limiter->decrease_committed(committed_words_in_range);
199
200 // ... and global counters...
201 _total_committed_words_counter->decrement_by(committed_words_in_range);
202
203 // ... and update the commit mask.
204 _commit_mask.mark_range_as_uncommitted(p, word_size);
205
206 #ifdef ASSERT
207 // The commit boundary maintained in the CommitLimiter should be equal the sum of committed words
208 // in both class and non-class vslist (outside gtests).
209 if (_commit_limiter == CommitLimiter::globalLimiter()) { // We are outside a test scenario
210 assert(_commit_limiter->committed_words() == RunningCounters::committed_words(), "counter mismatch");
211 }
212 #endif
213 InternalStats::inc_num_space_uncommitted();
214 }
215
216 //// creation, destruction ////
217
218 VirtualSpaceNode::VirtualSpaceNode(ReservedSpace rs, bool owns_rs, CommitLimiter* limiter,
219 SizeCounter* reserve_counter, SizeCounter* commit_counter) :
220 _next(nullptr),
221 _rs(rs),
222 _owns_rs(owns_rs),
223 _base((MetaWord*)rs.base()),
224 _word_size(rs.size() / BytesPerWord),
225 _used_words(0),
226 _commit_mask((MetaWord*)rs.base(), rs.size() / BytesPerWord),
227 _root_chunk_area_lut((MetaWord*)rs.base(), rs.size() / BytesPerWord),
228 _commit_limiter(limiter),
229 _total_reserved_words_counter(reserve_counter),
230 _total_committed_words_counter(commit_counter)
231 {
232 UL2(debug, "born (word_size " SIZE_FORMAT ").", _word_size);
233
234 // Update reserved counter in vslist
235 _total_reserved_words_counter->increment_by(_word_size);
236
237 assert_is_aligned(_base, chunklevel::MAX_CHUNK_BYTE_SIZE);
238 assert_is_aligned(_word_size, chunklevel::MAX_CHUNK_WORD_SIZE);
239
240 // Poison the memory region. It will be unpoisoned later on a per-chunk base for chunks that are
241 // handed to arenas.
242 ASAN_POISON_MEMORY_REGION(rs.base(), rs.size());
243
244 // Register memory region related to Metaspace. The Metaspace contains lots of pointers to malloc
245 // memory.
246 LSAN_REGISTER_ROOT_REGION(rs.base(), rs.size());
247 }
248
249 // Create a node of a given size (it will create its own space).
250 VirtualSpaceNode* VirtualSpaceNode::create_node(size_t word_size,
251 CommitLimiter* limiter, SizeCounter* reserve_words_counter,
252 SizeCounter* commit_words_counter)
253 {
254 DEBUG_ONLY(assert_is_aligned(word_size, chunklevel::MAX_CHUNK_WORD_SIZE);)
255 ReservedSpace rs(word_size * BytesPerWord,
256 Settings::virtual_space_node_reserve_alignment_words() * BytesPerWord,
257 os::vm_page_size());
258 if (!rs.is_reserved()) {
259 vm_exit_out_of_memory(word_size * BytesPerWord, OOM_MMAP_ERROR, "Failed to reserve memory for metaspace");
260 }
261 MemTracker::record_virtual_memory_type(rs.base(), mtMetaspace);
262 assert_is_aligned(rs.base(), chunklevel::MAX_CHUNK_BYTE_SIZE);
263 InternalStats::inc_num_vsnodes_births();
264 return new VirtualSpaceNode(rs, true, limiter, reserve_words_counter, commit_words_counter);
265 }
266
267 // Create a node over an existing space
268 VirtualSpaceNode* VirtualSpaceNode::create_node(ReservedSpace rs, CommitLimiter* limiter,
269 SizeCounter* reserve_words_counter, SizeCounter* commit_words_counter)
270 {
271 InternalStats::inc_num_vsnodes_births();
272 return new VirtualSpaceNode(rs, false, limiter, reserve_words_counter, commit_words_counter);
273 }
274
275 VirtualSpaceNode::~VirtualSpaceNode() {
276 DEBUG_ONLY(verify_locked();)
277
278 // Unregister memory region related to Metaspace.
279 LSAN_UNREGISTER_ROOT_REGION(_rs.base(), _rs.size());
280
281 // Undo the poisoning before potentially unmapping memory. This ensures that future mappings at
282 // the same address do not unexpectedly fail with use-after-poison.
283 ASAN_UNPOISON_MEMORY_REGION(_rs.base(), _rs.size());
284
285 UL(debug, ": dies.");
286
287 if (_owns_rs) {
288 _rs.release();
289 }
290
291 // Update counters in vslist
292 size_t committed = committed_words();
293 _total_committed_words_counter->decrement_by(committed);
294 _total_reserved_words_counter->decrement_by(_word_size);
295
296 // ... and tell commit limiter
297 _commit_limiter->decrease_committed(committed);
298
299 InternalStats::inc_num_vsnodes_deaths();
300 }
301
302 //// Chunk allocation, splitting, merging /////
303
304 // Allocate a root chunk from this node. Will fail and return null if the node is full
305 // - if we used up the whole address space of this node's memory region.
306 // (in case this node backs compressed class space, this is how we hit
307 // CompressedClassSpaceSize).
308 // Note that this just returns reserved memory; caller must take care of committing this
309 // chunk before using it.
310 Metachunk* VirtualSpaceNode::allocate_root_chunk() {
311 assert_lock_strong(Metaspace_lock);
312 assert_is_aligned(free_words(), chunklevel::MAX_CHUNK_WORD_SIZE);
313
314 if (free_words() >= chunklevel::MAX_CHUNK_WORD_SIZE) {
315
316 MetaWord* loc = _base + _used_words;
317 _used_words += chunklevel::MAX_CHUNK_WORD_SIZE;
318
319 RootChunkArea* rca = _root_chunk_area_lut.get_area_by_address(loc);
320
321 // Create a root chunk header and initialize it;
322 Metachunk* c = rca->alloc_root_chunk_header(this);
323 assert(c->base() == loc && c->vsnode() == this &&
324 c->is_free(), "Sanity");
325 DEBUG_ONLY(c->verify();)
326
327 UL2(debug, "new root chunk " METACHUNK_FORMAT ".", METACHUNK_FORMAT_ARGS(c));
328 return c;
329 }
330 return nullptr; // Node is full.
331 }
332
333 // Given a chunk c, split it recursively until you get a chunk of the given target_level.
334 //
335 // The resulting target chunk resides at the same address as the original chunk.
336 // The resulting splinters are added to freelists.
337 void VirtualSpaceNode::split(chunklevel_t target_level, Metachunk* c, FreeChunkListVector* freelists) {
338 assert_lock_strong(Metaspace_lock);
339 // Get the area associated with this chunk and let it handle the splitting
340 RootChunkArea* rca = _root_chunk_area_lut.get_area_by_address(c->base());
341 DEBUG_ONLY(rca->verify_area_is_ideally_merged();)
342 rca->split(target_level, c, freelists);
343 }
344
345 // Given a chunk, attempt to merge it recursively with its neighboring chunks.
346 //
347 // If successful (merged at least once), returns address of
348 // the merged chunk; null otherwise.
349 //
350 // The merged chunks are removed from the freelists.
351 //
352 // !!! Please note that if this method returns a non-null value, the
353 // original chunk will be invalid and should not be accessed anymore! !!!
354 Metachunk* VirtualSpaceNode::merge(Metachunk* c, FreeChunkListVector* freelists) {
355 assert(c != nullptr && c->is_free(), "Sanity");
356 assert_lock_strong(Metaspace_lock);
357
358 // Get the rca associated with this chunk and let it handle the merging
359 RootChunkArea* rca = _root_chunk_area_lut.get_area_by_address(c->base());
360 Metachunk* c2 = rca->merge(c, freelists);
361 DEBUG_ONLY(rca->verify_area_is_ideally_merged();)
362 return c2;
363 }
364
365 // Given a chunk c, which must be "in use" and must not be a root chunk, attempt to
366 // enlarge it in place by claiming its trailing buddy.
367 //
368 // This will only work if c is the leader of the buddy pair and the trailing buddy is free.
369 //
370 // If successful, the follower chunk will be removed from the freelists, the leader chunk c will
371 // double in size (level decreased by one).
372 //
373 // On success, true is returned, false otherwise.
374 bool VirtualSpaceNode::attempt_enlarge_chunk(Metachunk* c, FreeChunkListVector* freelists) {
375 assert(c != nullptr && c->is_in_use() && !c->is_root_chunk(), "Sanity");
376 assert_lock_strong(Metaspace_lock);
377
378 // Get the rca associated with this chunk and let it handle the merging
379 RootChunkArea* rca = _root_chunk_area_lut.get_area_by_address(c->base());
380
381 bool rc = rca->attempt_enlarge_chunk(c, freelists);
382 DEBUG_ONLY(rca->verify_area_is_ideally_merged();)
383 if (rc) {
384 InternalStats::inc_num_chunks_enlarged();
385 }
386
387 return rc;
388 }
389
390 void VirtualSpaceNode::print_on(outputStream* st) const {
391 size_t scale = K;
392
393 st->print("base " PTR_FORMAT ": ", p2i(base()));
394 st->print("reserved=");
395 print_scaled_words(st, word_size(), scale);
396 st->print(", committed=");
397 print_scaled_words_and_percentage(st, committed_words(), word_size(), scale);
398 st->print(", used=");
399 print_scaled_words_and_percentage(st, used_words(), word_size(), scale);
400
401 st->cr();
402 _root_chunk_area_lut.print_on(st);
403 _commit_mask.print_on(st);
404 }
405
406 // Returns size, in words, of committed space in this node alone.
407 // Note: iterates over commit mask and hence may be a tad expensive on large nodes.
408 size_t VirtualSpaceNode::committed_words() const {
409 return _commit_mask.get_committed_size();
410 }
411
412 #ifdef ASSERT
413 void VirtualSpaceNode::verify() const {
414 MutexLocker fcl(Metaspace_lock, Mutex::_no_safepoint_check_flag);
415 verify_locked();
416 }
417
418 volatile int test_access = 0;
419
420 // Verify counters and basic structure. Slow mode: verify all chunks in depth
421 void VirtualSpaceNode::verify_locked() const {
422 assert_lock_strong(Metaspace_lock);
423 assert(base() != nullptr, "Invalid base");
424 assert(base() == (MetaWord*)_rs.base() &&
425 word_size() == _rs.size() / BytesPerWord,
426 "Sanity");
427 assert_is_aligned(base(), chunklevel::MAX_CHUNK_BYTE_SIZE);
428 assert(used_words() <= word_size(), "Sanity");
429 // Since we only ever hand out root chunks from a vsnode, top should always be aligned
430 // to root chunk size.
431 assert_is_aligned(used_words(), chunklevel::MAX_CHUNK_WORD_SIZE);
432
433 _commit_mask.verify();
434
435 // Verify memory against commit mask.
436 SOMETIMES(
437 for (MetaWord* p = base(); p < base() + used_words(); p += os::vm_page_size()) {
438 if (_commit_mask.is_committed_address(p)) {
439 test_access += *(int*)p;
440 }
441 }
442 )
443
444 assert(committed_words() <= word_size(), "Sanity");
445 assert_is_aligned(committed_words(), Settings::commit_granule_words());
446 _root_chunk_area_lut.verify();
447 }
448
449 #endif
450
451 } // namespace metaspace