blob: 64e899b633371d252deaf057156408a8ea8f4625
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"); |
431 |