1 /*
2 * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2020 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
28 #include "memory/metaspace/msChunkManager.hpp"
29 #include "memory/metaspace/msFreeChunkList.hpp"
30 #include "memory/metaspace/msMetachunk.hpp"
31 #include "memory/metaspace/msSettings.hpp"
32 #include "memory/metaspace/msVirtualSpaceNode.hpp"
33 #include "runtime/mutexLocker.hpp"
34
35 #include "metaspaceGtestCommon.hpp"
36 #include "metaspaceGtestContexts.hpp"
37
38
39 using metaspace::ChunkManager;
40 using metaspace::FreeChunkListVector;
41 using metaspace::Metachunk;
42 using metaspace::Settings;
43 using metaspace::VirtualSpaceNode;
44 using namespace metaspace::chunklevel;
45
46 // Test ChunkManager::get_chunk
47 TEST_VM(metaspace, get_chunk) {
48
49 ChunkGtestContext context(8 * M);
50 Metachunk* c = NULL;
51
52 for (chunklevel_t pref_lvl = LOWEST_CHUNK_LEVEL; pref_lvl <= HIGHEST_CHUNK_LEVEL; pref_lvl++) {
53
54 for (chunklevel_t max_lvl = pref_lvl; max_lvl <= HIGHEST_CHUNK_LEVEL; max_lvl++) {
55
56 for (size_t min_committed_words = Settings::commit_granule_words();
57 min_committed_words <= word_size_for_level(max_lvl); min_committed_words *= 2) {
58 context.alloc_chunk_expect_success(&c, pref_lvl, max_lvl, min_committed_words);
59 context.return_chunk(c);
60 }
61 }
62 }
63 }
64
65 // Test ChunkManager::get_chunk, but with a commit limit.
66 TEST_VM(metaspace, get_chunk_with_commit_limit) {
67
68 const size_t commit_limit_words = 1 * M;
69 ChunkGtestContext context(commit_limit_words);
70 Metachunk* c = NULL;
71
72 for (chunklevel_t pref_lvl = LOWEST_CHUNK_LEVEL; pref_lvl <= HIGHEST_CHUNK_LEVEL; pref_lvl++) {
73
74 for (chunklevel_t max_lvl = pref_lvl; max_lvl <= HIGHEST_CHUNK_LEVEL; max_lvl++) {
75
76 for (size_t min_committed_words = Settings::commit_granule_words();
77 min_committed_words <= word_size_for_level(max_lvl); min_committed_words *= 2) {
78
79 if (min_committed_words <= commit_limit_words) {
80 context.alloc_chunk_expect_success(&c, pref_lvl, max_lvl, min_committed_words);
81 context.return_chunk(c);
82 } else {
83 context.alloc_chunk_expect_failure(pref_lvl, max_lvl, min_committed_words);
84 }
85
86 }
87 }
88 }
89 }
90
91 // Test that recommitting the used portion of a chunk will preserve the original content.
92 TEST_VM(metaspace, get_chunk_recommit) {
93
94 ChunkGtestContext context;
95 Metachunk* c = NULL;
96 context.alloc_chunk_expect_success(&c, ROOT_CHUNK_LEVEL, ROOT_CHUNK_LEVEL, 0);
97 context.uncommit_chunk_with_test(c);
98
99 context.commit_chunk_with_test(c, Settings::commit_granule_words());
100 context.allocate_from_chunk(c, Settings::commit_granule_words());
101
102 c->ensure_committed(Settings::commit_granule_words());
103 check_range_for_pattern(c->base(), c->used_words(), (uintx)c);
104
105 c->ensure_committed(Settings::commit_granule_words() * 2);
106 check_range_for_pattern(c->base(), c->used_words(), (uintx)c);
107
108 context.return_chunk(c);
109
110 }
111
112 // Test ChunkManager::get_chunk, but with a reserve limit.
113 // (meaning, the underlying VirtualSpaceList cannot expand, like compressed class space).
114 TEST_VM(metaspace, get_chunk_with_reserve_limit) {
115
116 const size_t reserve_limit_words = word_size_for_level(ROOT_CHUNK_LEVEL);
117 const size_t commit_limit_words = 1024 * M; // just very high
118 ChunkGtestContext context(commit_limit_words, reserve_limit_words);
119
120 // Reserve limit works at root chunk size granularity: if the chunk manager cannot satisfy
121 // a request for a chunk from its freelists, it will acquire a new root chunk from the
122 // underlying virtual space list. If that list is full and cannot be expanded (think ccs)
123 // we should get an error.
124 // Testing this is simply testing a chunk allocation which should cause allocation of a new
125 // root chunk.
126
127 // Cause allocation of the firstone root chunk, should still work:
128 Metachunk* c = NULL;
129 context.alloc_chunk_expect_success(&c, HIGHEST_CHUNK_LEVEL);
130
131 // and this should need a new root chunk and hence fail:
132 context.alloc_chunk_expect_failure(ROOT_CHUNK_LEVEL);
133
134 context.return_chunk(c);
135
136 }
137
138 // Test MetaChunk::allocate
139 TEST_VM(metaspace, chunk_allocate_full) {
140
141 ChunkGtestContext context;
142
143 for (chunklevel_t lvl = LOWEST_CHUNK_LEVEL; lvl <= HIGHEST_CHUNK_LEVEL; lvl++) {
144 Metachunk* c = NULL;
145 context.alloc_chunk_expect_success(&c, lvl);
146 context.allocate_from_chunk(c, c->word_size());
147 context.return_chunk(c);
148 }
149
150 }
151
152 // Test MetaChunk::allocate
153 TEST_VM(metaspace, chunk_allocate_random) {
154
155 ChunkGtestContext context;
156
157 for (chunklevel_t lvl = LOWEST_CHUNK_LEVEL; lvl <= HIGHEST_CHUNK_LEVEL; lvl++) {
158
159 Metachunk* c = NULL;
160 context.alloc_chunk_expect_success(&c, lvl);
161 context.uncommit_chunk_with_test(c); // start out fully uncommitted
162
163 RandSizeGenerator rgen(1, c->word_size() / 30);
164 bool stop = false;
165
166 while (!stop) {
167 const size_t s = rgen.get();
168 if (s <= c->free_words()) {
169 context.commit_chunk_with_test(c, s);
170 context.allocate_from_chunk(c, s);
171 } else {
172 stop = true;
173 }
174
175 }
176 context.return_chunk(c);
177
178 }
179
180 }
181
182 TEST_VM(metaspace, chunk_buddy_stuff) {
183
184 for (chunklevel_t l = ROOT_CHUNK_LEVEL + 1; l <= HIGHEST_CHUNK_LEVEL; l++) {
185
186 ChunkGtestContext context;
187
188 // Allocate two chunks; since we know the first chunk is the first in its area,
189 // it has to be a leader, and the next one of the same size its buddy.
190
191 // (Note: strictly speaking the ChunkManager does not promise any placement but
192 // we know how the placement works so these tests make sense).
193
194 Metachunk* c1 = NULL;
195 context.alloc_chunk(&c1, CHUNK_LEVEL_1K);
196 EXPECT_TRUE(c1->is_leader());
197
198 Metachunk* c2 = NULL;
199 context.alloc_chunk(&c2, CHUNK_LEVEL_1K);
200 EXPECT_FALSE(c2->is_leader());
201
202 // buddies are adjacent in memory
203 // (next/prev_in_vs needs lock)
204 {
205 MutexLocker fcl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
206 EXPECT_EQ(c1->next_in_vs(), c2);
207 EXPECT_EQ(c1->end(), c2->base());
208 EXPECT_NULL(c1->prev_in_vs()); // since we know this is the first in the area
209 EXPECT_EQ(c2->prev_in_vs(), c1);
210 }
211
212 context.return_chunk(c1);
213 context.return_chunk(c2);
214
215 }
216
217 }
218
219 TEST_VM(metaspace, chunk_allocate_with_commit_limit) {
220
221 // This test does not make sense if commit-on-demand is off
222 if (Settings::new_chunks_are_fully_committed()) {
223 return;
224 }
225
226 const size_t granule_sz = Settings::commit_granule_words();
227 const size_t commit_limit = granule_sz * 3;
228 ChunkGtestContext context(commit_limit);
229
230 // A big chunk, but uncommitted.
231 Metachunk* c = NULL;
232 context.alloc_chunk_expect_success(&c, ROOT_CHUNK_LEVEL, ROOT_CHUNK_LEVEL, 0);
233 context.uncommit_chunk_with_test(c); // ... just to make sure.
234
235 // first granule...
236 context.commit_chunk_with_test(c, granule_sz);
237 context.allocate_from_chunk(c, granule_sz);
238
239 // second granule...
240 context.commit_chunk_with_test(c, granule_sz);
241 context.allocate_from_chunk(c, granule_sz);
242
243 // third granule...
244 context.commit_chunk_with_test(c, granule_sz);
245 context.allocate_from_chunk(c, granule_sz);
246
247 // This should fail now.
248 context.commit_chunk_expect_failure(c, granule_sz);
249
250 context.return_chunk(c);
251
252 }
253
254 // Test splitting a chunk
255 TEST_VM(metaspace, chunk_split_and_merge) {
256
257 // Split works like this:
258 //
259 // ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
260 // | A |
261 // ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
262 //
263 // ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
264 // | A' | b | c | d | e |
265 // ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
266 //
267 // A original chunk (A) is split to form a target chunk (A') and as a result splinter
268 // chunks form (b..e). A' is the leader of the (A',b) pair, which is the leader of the
269 // ((A',b), c) pair and so on. In other words, A' will be a leader chunk, all splinter
270 // chunks are follower chunks.
271 //
272 // Merging reverses this operation:
273 //
274 // ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
275 // | A | b | c | d | e |
276 // ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
277 //
278 // ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
279 // | A' |
280 // ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
281 //
282 // (A) will be merged with its buddy b, (A+b) with its buddy c and so on. The result
283 // chunk is A'.
284 // Note that merging also works, of course, if we were to start the merge at (b) (so,
285 // with a follower chunk, not a leader). Also, at any point in the merge
286 // process we may arrive at a follower chunk. So, the fact that in this test
287 // we only expect a leader merge is a feature of the test, and of the fact that we
288 // start each split test with a fresh ChunkTestsContext.
289
290 // Note: Splitting and merging chunks is usually done from within the ChunkManager and
291 // subject to a lot of assumptions and hence asserts. Here, we have to explicitly use
292 // VirtualSpaceNode::split/::merge and therefore have to observe rules:
293 // - both split and merge expect free chunks, so state has to be "free"
294 // - but that would trigger the "ideally merged" assertion in the RootChunkArea, so the
295 // original chunk has to be a root chunk, we cannot just split any chunk manually.
296 // - Also, after the split we have to completely re-merge to avoid triggering asserts
297 // in ~RootChunkArea()
298 // - finally we have to lock manually
299
300 ChunkGtestContext context;
301
302 const chunklevel_t orig_lvl = ROOT_CHUNK_LEVEL;
303 for (chunklevel_t target_lvl = orig_lvl + 1; target_lvl <= HIGHEST_CHUNK_LEVEL; target_lvl++) {
304
305 // Split a fully committed chunk. The resulting chunk should be fully
306 // committed as well, and have its content preserved.
307 Metachunk* c = NULL;
308 context.alloc_chunk_expect_success(&c, orig_lvl);
309
310 // We allocate from this chunk to be able to completely paint the payload.
311 context.allocate_from_chunk(c, c->word_size());
312
313 const uintx canary = os::random();
314 fill_range_with_pattern(c->base(), c->word_size(), canary);
315
316 FreeChunkListVector splinters;
317
318 {
319 // Splitting/Merging chunks is usually done by the chunkmanager, and no explicit
320 // outside API exists. So we split/merge chunks via the underlying vs node, directly.
321 // This means that we have to go through some extra hoops to not trigger any asserts.
322 MutexLocker fcl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
323 c->reset_used_words();
324 c->set_free();
325 c->vsnode()->split(target_lvl, c, &splinters);
326 }
327
328 DEBUG_ONLY(context.verify();)
329
330 EXPECT_EQ(c->level(), target_lvl);
331 EXPECT_TRUE(c->is_fully_committed());
332 EXPECT_FALSE(c->is_root_chunk());
333 EXPECT_TRUE(c->is_leader());
334
335 check_range_for_pattern(c->base(), c->word_size(), canary);
336
337 // I expect splinter chunks (one for each splinter level:
338 // e.g. splitting a 1M chunk to get a 64K chunk should yield splinters: [512K, 256K, 128K, 64K]
339 for (chunklevel_t l = LOWEST_CHUNK_LEVEL; l < HIGHEST_CHUNK_LEVEL; l++) {
340 const Metachunk* c2 = splinters.first_at_level(l);
341 if (l > orig_lvl && l <= target_lvl) {
342 EXPECT_NOT_NULL(c2);
343 EXPECT_EQ(c2->level(), l);
344 EXPECT_TRUE(c2->is_free());
345 EXPECT_TRUE(!c2->is_leader());
346 DEBUG_ONLY(c2->verify());
347 check_range_for_pattern(c2->base(), c2->word_size(), canary);
348 } else {
349 EXPECT_NULL(c2);
350 }
351 }
352
353 // Revert the split by using merge. This should result in all splinters coalescing
354 // to one chunk.
355 {
356 MutexLocker fcl(MetaspaceExpand_lock, Mutex::_no_safepoint_check_flag);
357 Metachunk* merged = c->vsnode()->merge(c, &splinters);
358
359 // the merged chunk should occupy the same address as the splinter
360 // since it should have been the leader in the split.
361 EXPECT_EQ(merged, c);
362 EXPECT_TRUE(merged->is_root_chunk() || merged->is_leader());
363
364 // Splitting should have arrived at the original chunk since none of the splinters are in use.
365 EXPECT_EQ(c->level(), orig_lvl);
366
367 // All splinters should have been removed from the list
368 EXPECT_EQ(splinters.num_chunks(), 0);
369 }
370
371 context.return_chunk(c);
372
373 }
374
375 }
376
377 TEST_VM(metaspace, chunk_enlarge_in_place) {
378
379 ChunkGtestContext context;
380
381 // Starting with the smallest chunk size, attempt to enlarge the chunk in place until we arrive
382 // at root chunk size. Since the state is clean, this should work.
383
384 Metachunk* c = NULL;
385 context.alloc_chunk_expect_success(&c, HIGHEST_CHUNK_LEVEL);
386
387 chunklevel_t l = c->level();
388
389 while (l != ROOT_CHUNK_LEVEL) {
390
391 // commit and allocate from chunk to pattern it...
392 const size_t original_chunk_size = c->word_size();
393 context.commit_chunk_with_test(c, c->free_words());
394 context.allocate_from_chunk(c, c->free_words());
395
396 size_t used_before = c->used_words();
397 size_t free_before = c->free_words();
398 size_t free_below_committed_before = c->free_below_committed_words();
399 const MetaWord* top_before = c->top();
400
401 EXPECT_TRUE(context.cm().attempt_enlarge_chunk(c));
402 EXPECT_EQ(l - 1, c->level());
403 EXPECT_EQ(c->word_size(), original_chunk_size * 2);
404
405 // Used words should not have changed
406 EXPECT_EQ(c->used_words(), used_before);
407 EXPECT_EQ(c->top(), top_before);
408
409 // free words should be expanded by the old size (since old chunk is doubled in size)
410 EXPECT_EQ(c->free_words(), free_before + original_chunk_size);
411
412 // free below committed can be larger but never smaller
413 EXPECT_GE(c->free_below_committed_words(), free_below_committed_before);
414
415 // Old content should be preserved
416 check_range_for_pattern(c->base(), original_chunk_size, (uintx)c);
417
418 l = c->level();
419 }
420
421 context.return_chunk(c);
422
423 }
424