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1 | /* | |
2 | * Resizable, Scalable, Concurrent Hash Table | |
3 | * | |
4 | * Copyright (c) 2014-2015 Thomas Graf <tgraf@suug.ch> | |
5 | * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | /************************************************************************** | |
13 | * Self Test | |
14 | **************************************************************************/ | |
15 | ||
16 | #include <linux/init.h> | |
17 | #include <linux/jhash.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/kthread.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/rcupdate.h> | |
22 | #include <linux/rhashtable.h> | |
23 | #include <linux/semaphore.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/sched.h> | |
26 | #include <linux/vmalloc.h> | |
27 | ||
28 | #define MAX_ENTRIES 1000000 | |
29 | #define TEST_INSERT_FAIL INT_MAX | |
30 | ||
31 | static int entries = 50000; | |
32 | module_param(entries, int, 0); | |
33 | MODULE_PARM_DESC(entries, "Number of entries to add (default: 50000)"); | |
34 | ||
35 | static int runs = 4; | |
36 | module_param(runs, int, 0); | |
37 | MODULE_PARM_DESC(runs, "Number of test runs per variant (default: 4)"); | |
38 | ||
39 | static int max_size = 0; | |
40 | module_param(max_size, int, 0); | |
41 | MODULE_PARM_DESC(max_size, "Maximum table size (default: calculated)"); | |
42 | ||
43 | static bool shrinking = false; | |
44 | module_param(shrinking, bool, 0); | |
45 | MODULE_PARM_DESC(shrinking, "Enable automatic shrinking (default: off)"); | |
46 | ||
47 | static int size = 8; | |
48 | module_param(size, int, 0); | |
49 | MODULE_PARM_DESC(size, "Initial size hint of table (default: 8)"); | |
50 | ||
51 | static int tcount = 10; | |
52 | module_param(tcount, int, 0); | |
53 | MODULE_PARM_DESC(tcount, "Number of threads to spawn (default: 10)"); | |
54 | ||
55 | static bool enomem_retry = false; | |
56 | module_param(enomem_retry, bool, 0); | |
57 | MODULE_PARM_DESC(enomem_retry, "Retry insert even if -ENOMEM was returned (default: off)"); | |
58 | ||
59 | struct test_obj { | |
60 | int value; | |
61 | struct rhash_head node; | |
62 | }; | |
63 | ||
64 | struct thread_data { | |
65 | int id; | |
66 | struct task_struct *task; | |
67 | struct test_obj *objs; | |
68 | }; | |
69 | ||
70 | static struct test_obj array[MAX_ENTRIES]; | |
71 | ||
72 | static struct rhashtable_params test_rht_params = { | |
73 | .head_offset = offsetof(struct test_obj, node), | |
74 | .key_offset = offsetof(struct test_obj, value), | |
75 | .key_len = sizeof(int), | |
76 | .hashfn = jhash, | |
77 | .nulls_base = (3U << RHT_BASE_SHIFT), | |
78 | }; | |
79 | ||
80 | static struct semaphore prestart_sem; | |
81 | static struct semaphore startup_sem = __SEMAPHORE_INITIALIZER(startup_sem, 0); | |
82 | ||
83 | static int insert_retry(struct rhashtable *ht, struct rhash_head *obj, | |
84 | const struct rhashtable_params params) | |
85 | { | |
86 | int err, retries = -1, enomem_retries = 0; | |
87 | ||
88 | do { | |
89 | retries++; | |
90 | cond_resched(); | |
91 | err = rhashtable_insert_fast(ht, obj, params); | |
92 | if (err == -ENOMEM && enomem_retry) { | |
93 | enomem_retries++; | |
94 | err = -EBUSY; | |
95 | } | |
96 | } while (err == -EBUSY); | |
97 | ||
98 | if (enomem_retries) | |
99 | pr_info(" %u insertions retried after -ENOMEM\n", | |
100 | enomem_retries); | |
101 | ||
102 | return err ? : retries; | |
103 | } | |
104 | ||
105 | static int __init test_rht_lookup(struct rhashtable *ht) | |
106 | { | |
107 | unsigned int i; | |
108 | ||
109 | for (i = 0; i < entries * 2; i++) { | |
110 | struct test_obj *obj; | |
111 | bool expected = !(i % 2); | |
112 | u32 key = i; | |
113 | ||
114 | if (array[i / 2].value == TEST_INSERT_FAIL) | |
115 | expected = false; | |
116 | ||
117 | obj = rhashtable_lookup_fast(ht, &key, test_rht_params); | |
118 | ||
119 | if (expected && !obj) { | |
120 | pr_warn("Test failed: Could not find key %u\n", key); | |
121 | return -ENOENT; | |
122 | } else if (!expected && obj) { | |
123 | pr_warn("Test failed: Unexpected entry found for key %u\n", | |
124 | key); | |
125 | return -EEXIST; | |
126 | } else if (expected && obj) { | |
127 | if (obj->value != i) { | |
128 | pr_warn("Test failed: Lookup value mismatch %u!=%u\n", | |
129 | obj->value, i); | |
130 | return -EINVAL; | |
131 | } | |
132 | } | |
133 | ||
134 | cond_resched_rcu(); | |
135 | } | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | static void test_bucket_stats(struct rhashtable *ht) | |
141 | { | |
142 | unsigned int err, total = 0, chain_len = 0; | |
143 | struct rhashtable_iter hti; | |
144 | struct rhash_head *pos; | |
145 | ||
146 | err = rhashtable_walk_init(ht, &hti, GFP_KERNEL); | |
147 | if (err) { | |
148 | pr_warn("Test failed: allocation error"); | |
149 | return; | |
150 | } | |
151 | ||
152 | err = rhashtable_walk_start(&hti); | |
153 | if (err && err != -EAGAIN) { | |
154 | pr_warn("Test failed: iterator failed: %d\n", err); | |
155 | return; | |
156 | } | |
157 | ||
158 | while ((pos = rhashtable_walk_next(&hti))) { | |
159 | if (PTR_ERR(pos) == -EAGAIN) { | |
160 | pr_info("Info: encountered resize\n"); | |
161 | chain_len++; | |
162 | continue; | |
163 | } else if (IS_ERR(pos)) { | |
164 | pr_warn("Test failed: rhashtable_walk_next() error: %ld\n", | |
165 | PTR_ERR(pos)); | |
166 | break; | |
167 | } | |
168 | ||
169 | total++; | |
170 | } | |
171 | ||
172 | rhashtable_walk_stop(&hti); | |
173 | rhashtable_walk_exit(&hti); | |
174 | ||
175 | pr_info(" Traversal complete: counted=%u, nelems=%u, entries=%d, table-jumps=%u\n", | |
176 | total, atomic_read(&ht->nelems), entries, chain_len); | |
177 | ||
178 | if (total != atomic_read(&ht->nelems) || total != entries) | |
179 | pr_warn("Test failed: Total count mismatch ^^^"); | |
180 | } | |
181 | ||
182 | static s64 __init test_rhashtable(struct rhashtable *ht) | |
183 | { | |
184 | struct test_obj *obj; | |
185 | int err; | |
186 | unsigned int i, insert_retries = 0; | |
187 | s64 start, end; | |
188 | ||
189 | /* | |
190 | * Insertion Test: | |
191 | * Insert entries into table with all keys even numbers | |
192 | */ | |
193 | pr_info(" Adding %d keys\n", entries); | |
194 | start = ktime_get_ns(); | |
195 | for (i = 0; i < entries; i++) { | |
196 | struct test_obj *obj = &array[i]; | |
197 | ||
198 | obj->value = i * 2; | |
199 | err = insert_retry(ht, &obj->node, test_rht_params); | |
200 | if (err > 0) | |
201 | insert_retries += err; | |
202 | else if (err) | |
203 | return err; | |
204 | } | |
205 | ||
206 | if (insert_retries) | |
207 | pr_info(" %u insertions retried due to memory pressure\n", | |
208 | insert_retries); | |
209 | ||
210 | test_bucket_stats(ht); | |
211 | rcu_read_lock(); | |
212 | test_rht_lookup(ht); | |
213 | rcu_read_unlock(); | |
214 | ||
215 | test_bucket_stats(ht); | |
216 | ||
217 | pr_info(" Deleting %d keys\n", entries); | |
218 | for (i = 0; i < entries; i++) { | |
219 | u32 key = i * 2; | |
220 | ||
221 | if (array[i].value != TEST_INSERT_FAIL) { | |
222 | obj = rhashtable_lookup_fast(ht, &key, test_rht_params); | |
223 | BUG_ON(!obj); | |
224 | ||
225 | rhashtable_remove_fast(ht, &obj->node, test_rht_params); | |
226 | } | |
227 | ||
228 | cond_resched(); | |
229 | } | |
230 | ||
231 | end = ktime_get_ns(); | |
232 | pr_info(" Duration of test: %lld ns\n", end - start); | |
233 | ||
234 | return end - start; | |
235 | } | |
236 | ||
237 | static struct rhashtable ht; | |
238 | ||
239 | static int thread_lookup_test(struct thread_data *tdata) | |
240 | { | |
241 | int i, err = 0; | |
242 | ||
243 | for (i = 0; i < entries; i++) { | |
244 | struct test_obj *obj; | |
245 | int key = (tdata->id << 16) | i; | |
246 | ||
247 | obj = rhashtable_lookup_fast(&ht, &key, test_rht_params); | |
248 | if (obj && (tdata->objs[i].value == TEST_INSERT_FAIL)) { | |
249 | pr_err(" found unexpected object %d\n", key); | |
250 | err++; | |
251 | } else if (!obj && (tdata->objs[i].value != TEST_INSERT_FAIL)) { | |
252 | pr_err(" object %d not found!\n", key); | |
253 | err++; | |
254 | } else if (obj && (obj->value != key)) { | |
255 | pr_err(" wrong object returned (got %d, expected %d)\n", | |
256 | obj->value, key); | |
257 | err++; | |
258 | } | |
259 | ||
260 | cond_resched(); | |
261 | } | |
262 | return err; | |
263 | } | |
264 | ||
265 | static int threadfunc(void *data) | |
266 | { | |
267 | int i, step, err = 0, insert_retries = 0; | |
268 | struct thread_data *tdata = data; | |
269 | ||
270 | up(&prestart_sem); | |
271 | if (down_interruptible(&startup_sem)) | |
272 | pr_err(" thread[%d]: down_interruptible failed\n", tdata->id); | |
273 | ||
274 | for (i = 0; i < entries; i++) { | |
275 | tdata->objs[i].value = (tdata->id << 16) | i; | |
276 | err = insert_retry(&ht, &tdata->objs[i].node, test_rht_params); | |
277 | if (err > 0) { | |
278 | insert_retries += err; | |
279 | } else if (err) { | |
280 | pr_err(" thread[%d]: rhashtable_insert_fast failed\n", | |
281 | tdata->id); | |
282 | goto out; | |
283 | } | |
284 | } | |
285 | if (insert_retries) | |
286 | pr_info(" thread[%d]: %u insertions retried due to memory pressure\n", | |
287 | tdata->id, insert_retries); | |
288 | ||
289 | err = thread_lookup_test(tdata); | |
290 | if (err) { | |
291 | pr_err(" thread[%d]: rhashtable_lookup_test failed\n", | |
292 | tdata->id); | |
293 | goto out; | |
294 | } | |
295 | ||
296 | for (step = 10; step > 0; step--) { | |
297 | for (i = 0; i < entries; i += step) { | |
298 | if (tdata->objs[i].value == TEST_INSERT_FAIL) | |
299 | continue; | |
300 | err = rhashtable_remove_fast(&ht, &tdata->objs[i].node, | |
301 | test_rht_params); | |
302 | if (err) { | |
303 | pr_err(" thread[%d]: rhashtable_remove_fast failed\n", | |
304 | tdata->id); | |
305 | goto out; | |
306 | } | |
307 | tdata->objs[i].value = TEST_INSERT_FAIL; | |
308 | ||
309 | cond_resched(); | |
310 | } | |
311 | err = thread_lookup_test(tdata); | |
312 | if (err) { | |
313 | pr_err(" thread[%d]: rhashtable_lookup_test (2) failed\n", | |
314 | tdata->id); | |
315 | goto out; | |
316 | } | |
317 | } | |
318 | out: | |
319 | while (!kthread_should_stop()) { | |
320 | set_current_state(TASK_INTERRUPTIBLE); | |
321 | schedule(); | |
322 | } | |
323 | return err; | |
324 | } | |
325 | ||
326 | static int __init test_rht_init(void) | |
327 | { | |
328 | int i, err, started_threads = 0, failed_threads = 0; | |
329 | u64 total_time = 0; | |
330 | struct thread_data *tdata; | |
331 | struct test_obj *objs; | |
332 | ||
333 | entries = min(entries, MAX_ENTRIES); | |
334 | ||
335 | test_rht_params.automatic_shrinking = shrinking; | |
336 | test_rht_params.max_size = max_size ? : roundup_pow_of_two(entries); | |
337 | test_rht_params.nelem_hint = size; | |
338 | ||
339 | pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n", | |
340 | size, max_size, shrinking); | |
341 | ||
342 | for (i = 0; i < runs; i++) { | |
343 | s64 time; | |
344 | ||
345 | pr_info("Test %02d:\n", i); | |
346 | memset(&array, 0, sizeof(array)); | |
347 | err = rhashtable_init(&ht, &test_rht_params); | |
348 | if (err < 0) { | |
349 | pr_warn("Test failed: Unable to initialize hashtable: %d\n", | |
350 | err); | |
351 | continue; | |
352 | } | |
353 | ||
354 | time = test_rhashtable(&ht); | |
355 | rhashtable_destroy(&ht); | |
356 | if (time < 0) { | |
357 | pr_warn("Test failed: return code %lld\n", time); | |
358 | return -EINVAL; | |
359 | } | |
360 | ||
361 | total_time += time; | |
362 | } | |
363 | ||
364 | do_div(total_time, runs); | |
365 | pr_info("Average test time: %llu\n", total_time); | |
366 | ||
367 | if (!tcount) | |
368 | return 0; | |
369 | ||
370 | pr_info("Testing concurrent rhashtable access from %d threads\n", | |
371 | tcount); | |
372 | sema_init(&prestart_sem, 1 - tcount); | |
373 | tdata = vzalloc(tcount * sizeof(struct thread_data)); | |
374 | if (!tdata) | |
375 | return -ENOMEM; | |
376 | objs = vzalloc(tcount * entries * sizeof(struct test_obj)); | |
377 | if (!objs) { | |
378 | vfree(tdata); | |
379 | return -ENOMEM; | |
380 | } | |
381 | ||
382 | test_rht_params.max_size = max_size ? : | |
383 | roundup_pow_of_two(tcount * entries); | |
384 | err = rhashtable_init(&ht, &test_rht_params); | |
385 | if (err < 0) { | |
386 | pr_warn("Test failed: Unable to initialize hashtable: %d\n", | |
387 | err); | |
388 | vfree(tdata); | |
389 | vfree(objs); | |
390 | return -EINVAL; | |
391 | } | |
392 | for (i = 0; i < tcount; i++) { | |
393 | tdata[i].id = i; | |
394 | tdata[i].objs = objs + i * entries; | |
395 | tdata[i].task = kthread_run(threadfunc, &tdata[i], | |
396 | "rhashtable_thrad[%d]", i); | |
397 | if (IS_ERR(tdata[i].task)) | |
398 | pr_err(" kthread_run failed for thread %d\n", i); | |
399 | else | |
400 | started_threads++; | |
401 | } | |
402 | if (down_interruptible(&prestart_sem)) | |
403 | pr_err(" down interruptible failed\n"); | |
404 | for (i = 0; i < tcount; i++) | |
405 | up(&startup_sem); | |
406 | for (i = 0; i < tcount; i++) { | |
407 | if (IS_ERR(tdata[i].task)) | |
408 | continue; | |
409 | if ((err = kthread_stop(tdata[i].task))) { | |
410 | pr_warn("Test failed: thread %d returned: %d\n", | |
411 | i, err); | |
412 | failed_threads++; | |
413 | } | |
414 | } | |
415 | pr_info("Started %d threads, %d failed\n", | |
416 | started_threads, failed_threads); | |
417 | rhashtable_destroy(&ht); | |
418 | vfree(tdata); | |
419 | vfree(objs); | |
420 | return 0; | |
421 | } | |
422 | ||
423 | static void __exit test_rht_exit(void) | |
424 | { | |
425 | } | |
426 | ||
427 | module_init(test_rht_init); | |
428 | module_exit(test_rht_exit); | |
429 | ||
430 | MODULE_LICENSE("GPL v2"); |