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 = 65536;
40 module_param(max_size, int, 0);
41 MODULE_PARM_DESC(runs, "Maximum table size (default: 65536)");
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 struct test_obj {
56 int value;
57 struct rhash_head node;
58 };
59
60 struct thread_data {
61 int id;
62 struct task_struct *task;
63 struct test_obj *objs;
64 };
65
66 static struct test_obj array[MAX_ENTRIES];
67
68 static struct rhashtable_params test_rht_params = {
69 .head_offset = offsetof(struct test_obj, node),
70 .key_offset = offsetof(struct test_obj, value),
71 .key_len = sizeof(int),
72 .hashfn = jhash,
73 .nulls_base = (3U << RHT_BASE_SHIFT),
74 };
75
76 static struct semaphore prestart_sem;
77 static struct semaphore startup_sem = __SEMAPHORE_INITIALIZER(startup_sem, 0);
78
test_rht_lookup(struct rhashtable * ht)79 static int __init test_rht_lookup(struct rhashtable *ht)
80 {
81 unsigned int i;
82
83 for (i = 0; i < entries * 2; i++) {
84 struct test_obj *obj;
85 bool expected = !(i % 2);
86 u32 key = i;
87
88 if (array[i / 2].value == TEST_INSERT_FAIL)
89 expected = false;
90
91 obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
92
93 if (expected && !obj) {
94 pr_warn("Test failed: Could not find key %u\n", key);
95 return -ENOENT;
96 } else if (!expected && obj) {
97 pr_warn("Test failed: Unexpected entry found for key %u\n",
98 key);
99 return -EEXIST;
100 } else if (expected && obj) {
101 if (obj->value != i) {
102 pr_warn("Test failed: Lookup value mismatch %u!=%u\n",
103 obj->value, i);
104 return -EINVAL;
105 }
106 }
107
108 cond_resched_rcu();
109 }
110
111 return 0;
112 }
113
test_bucket_stats(struct rhashtable * ht)114 static void test_bucket_stats(struct rhashtable *ht)
115 {
116 unsigned int err, total = 0, chain_len = 0;
117 struct rhashtable_iter hti;
118 struct rhash_head *pos;
119
120 err = rhashtable_walk_init(ht, &hti);
121 if (err) {
122 pr_warn("Test failed: allocation error");
123 return;
124 }
125
126 err = rhashtable_walk_start(&hti);
127 if (err && err != -EAGAIN) {
128 pr_warn("Test failed: iterator failed: %d\n", err);
129 return;
130 }
131
132 while ((pos = rhashtable_walk_next(&hti))) {
133 if (PTR_ERR(pos) == -EAGAIN) {
134 pr_info("Info: encountered resize\n");
135 chain_len++;
136 continue;
137 } else if (IS_ERR(pos)) {
138 pr_warn("Test failed: rhashtable_walk_next() error: %ld\n",
139 PTR_ERR(pos));
140 break;
141 }
142
143 total++;
144 }
145
146 rhashtable_walk_stop(&hti);
147 rhashtable_walk_exit(&hti);
148
149 pr_info(" Traversal complete: counted=%u, nelems=%u, entries=%d, table-jumps=%u\n",
150 total, atomic_read(&ht->nelems), entries, chain_len);
151
152 if (total != atomic_read(&ht->nelems) || total != entries)
153 pr_warn("Test failed: Total count mismatch ^^^");
154 }
155
test_rhashtable(struct rhashtable * ht)156 static s64 __init test_rhashtable(struct rhashtable *ht)
157 {
158 struct test_obj *obj;
159 int err;
160 unsigned int i, insert_fails = 0;
161 s64 start, end;
162
163 /*
164 * Insertion Test:
165 * Insert entries into table with all keys even numbers
166 */
167 pr_info(" Adding %d keys\n", entries);
168 start = ktime_get_ns();
169 for (i = 0; i < entries; i++) {
170 struct test_obj *obj = &array[i];
171
172 obj->value = i * 2;
173
174 err = rhashtable_insert_fast(ht, &obj->node, test_rht_params);
175 if (err == -ENOMEM || err == -EBUSY) {
176 /* Mark failed inserts but continue */
177 obj->value = TEST_INSERT_FAIL;
178 insert_fails++;
179 } else if (err) {
180 return err;
181 }
182
183 cond_resched();
184 }
185
186 if (insert_fails)
187 pr_info(" %u insertions failed due to memory pressure\n",
188 insert_fails);
189
190 test_bucket_stats(ht);
191 rcu_read_lock();
192 test_rht_lookup(ht);
193 rcu_read_unlock();
194
195 test_bucket_stats(ht);
196
197 pr_info(" Deleting %d keys\n", entries);
198 for (i = 0; i < entries; i++) {
199 u32 key = i * 2;
200
201 if (array[i].value != TEST_INSERT_FAIL) {
202 obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
203 BUG_ON(!obj);
204
205 rhashtable_remove_fast(ht, &obj->node, test_rht_params);
206 }
207
208 cond_resched();
209 }
210
211 end = ktime_get_ns();
212 pr_info(" Duration of test: %lld ns\n", end - start);
213
214 return end - start;
215 }
216
217 static struct rhashtable ht;
218
thread_lookup_test(struct thread_data * tdata)219 static int thread_lookup_test(struct thread_data *tdata)
220 {
221 int i, err = 0;
222
223 for (i = 0; i < entries; i++) {
224 struct test_obj *obj;
225 int key = (tdata->id << 16) | i;
226
227 obj = rhashtable_lookup_fast(&ht, &key, test_rht_params);
228 if (obj && (tdata->objs[i].value == TEST_INSERT_FAIL)) {
229 pr_err(" found unexpected object %d\n", key);
230 err++;
231 } else if (!obj && (tdata->objs[i].value != TEST_INSERT_FAIL)) {
232 pr_err(" object %d not found!\n", key);
233 err++;
234 } else if (obj && (obj->value != key)) {
235 pr_err(" wrong object returned (got %d, expected %d)\n",
236 obj->value, key);
237 err++;
238 }
239 }
240 return err;
241 }
242
threadfunc(void * data)243 static int threadfunc(void *data)
244 {
245 int i, step, err = 0, insert_fails = 0;
246 struct thread_data *tdata = data;
247
248 up(&prestart_sem);
249 if (down_interruptible(&startup_sem))
250 pr_err(" thread[%d]: down_interruptible failed\n", tdata->id);
251
252 for (i = 0; i < entries; i++) {
253 tdata->objs[i].value = (tdata->id << 16) | i;
254 err = rhashtable_insert_fast(&ht, &tdata->objs[i].node,
255 test_rht_params);
256 if (err == -ENOMEM || err == -EBUSY) {
257 tdata->objs[i].value = TEST_INSERT_FAIL;
258 insert_fails++;
259 } else if (err) {
260 pr_err(" thread[%d]: rhashtable_insert_fast failed\n",
261 tdata->id);
262 goto out;
263 }
264 }
265 if (insert_fails)
266 pr_info(" thread[%d]: %d insert failures\n",
267 tdata->id, insert_fails);
268
269 err = thread_lookup_test(tdata);
270 if (err) {
271 pr_err(" thread[%d]: rhashtable_lookup_test failed\n",
272 tdata->id);
273 goto out;
274 }
275
276 for (step = 10; step > 0; step--) {
277 for (i = 0; i < entries; i += step) {
278 if (tdata->objs[i].value == TEST_INSERT_FAIL)
279 continue;
280 err = rhashtable_remove_fast(&ht, &tdata->objs[i].node,
281 test_rht_params);
282 if (err) {
283 pr_err(" thread[%d]: rhashtable_remove_fast failed\n",
284 tdata->id);
285 goto out;
286 }
287 tdata->objs[i].value = TEST_INSERT_FAIL;
288 }
289 err = thread_lookup_test(tdata);
290 if (err) {
291 pr_err(" thread[%d]: rhashtable_lookup_test (2) failed\n",
292 tdata->id);
293 goto out;
294 }
295 }
296 out:
297 while (!kthread_should_stop()) {
298 set_current_state(TASK_INTERRUPTIBLE);
299 schedule();
300 }
301 return err;
302 }
303
test_rht_init(void)304 static int __init test_rht_init(void)
305 {
306 int i, err, started_threads = 0, failed_threads = 0;
307 u64 total_time = 0;
308 struct thread_data *tdata;
309 struct test_obj *objs;
310
311 entries = min(entries, MAX_ENTRIES);
312
313 test_rht_params.automatic_shrinking = shrinking;
314 test_rht_params.max_size = max_size;
315 test_rht_params.nelem_hint = size;
316
317 pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n",
318 size, max_size, shrinking);
319
320 for (i = 0; i < runs; i++) {
321 s64 time;
322
323 pr_info("Test %02d:\n", i);
324 memset(&array, 0, sizeof(array));
325 err = rhashtable_init(&ht, &test_rht_params);
326 if (err < 0) {
327 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
328 err);
329 continue;
330 }
331
332 time = test_rhashtable(&ht);
333 rhashtable_destroy(&ht);
334 if (time < 0) {
335 pr_warn("Test failed: return code %lld\n", time);
336 return -EINVAL;
337 }
338
339 total_time += time;
340 }
341
342 do_div(total_time, runs);
343 pr_info("Average test time: %llu\n", total_time);
344
345 if (!tcount)
346 return 0;
347
348 pr_info("Testing concurrent rhashtable access from %d threads\n",
349 tcount);
350 sema_init(&prestart_sem, 1 - tcount);
351 tdata = vzalloc(tcount * sizeof(struct thread_data));
352 if (!tdata)
353 return -ENOMEM;
354 objs = vzalloc(tcount * entries * sizeof(struct test_obj));
355 if (!objs) {
356 vfree(tdata);
357 return -ENOMEM;
358 }
359
360 err = rhashtable_init(&ht, &test_rht_params);
361 if (err < 0) {
362 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
363 err);
364 vfree(tdata);
365 vfree(objs);
366 return -EINVAL;
367 }
368 for (i = 0; i < tcount; i++) {
369 tdata[i].id = i;
370 tdata[i].objs = objs + i * entries;
371 tdata[i].task = kthread_run(threadfunc, &tdata[i],
372 "rhashtable_thrad[%d]", i);
373 if (IS_ERR(tdata[i].task))
374 pr_err(" kthread_run failed for thread %d\n", i);
375 else
376 started_threads++;
377 }
378 if (down_interruptible(&prestart_sem))
379 pr_err(" down interruptible failed\n");
380 for (i = 0; i < tcount; i++)
381 up(&startup_sem);
382 for (i = 0; i < tcount; i++) {
383 if (IS_ERR(tdata[i].task))
384 continue;
385 if ((err = kthread_stop(tdata[i].task))) {
386 pr_warn("Test failed: thread %d returned: %d\n",
387 i, err);
388 failed_threads++;
389 }
390 }
391 pr_info("Started %d threads, %d failed\n",
392 started_threads, failed_threads);
393 rhashtable_destroy(&ht);
394 vfree(tdata);
395 vfree(objs);
396 return 0;
397 }
398
test_rht_exit(void)399 static void __exit test_rht_exit(void)
400 {
401 }
402
403 module_init(test_rht_init);
404 module_exit(test_rht_exit);
405
406 MODULE_LICENSE("GPL v2");
407