Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[platform/kernel/linux-rpi.git] / lib / test_rhashtable.c
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/slab.h>
24 #include <linux/sched.h>
25 #include <linux/random.h>
26 #include <linux/vmalloc.h>
27 #include <linux/wait.h>
28
29 #define MAX_ENTRIES     1000000
30 #define TEST_INSERT_FAIL INT_MAX
31
32 static int parm_entries = 50000;
33 module_param(parm_entries, int, 0);
34 MODULE_PARM_DESC(parm_entries, "Number of entries to add (default: 50000)");
35
36 static int runs = 4;
37 module_param(runs, int, 0);
38 MODULE_PARM_DESC(runs, "Number of test runs per variant (default: 4)");
39
40 static int max_size = 0;
41 module_param(max_size, int, 0);
42 MODULE_PARM_DESC(max_size, "Maximum table size (default: calculated)");
43
44 static bool shrinking = false;
45 module_param(shrinking, bool, 0);
46 MODULE_PARM_DESC(shrinking, "Enable automatic shrinking (default: off)");
47
48 static int size = 8;
49 module_param(size, int, 0);
50 MODULE_PARM_DESC(size, "Initial size hint of table (default: 8)");
51
52 static int tcount = 10;
53 module_param(tcount, int, 0);
54 MODULE_PARM_DESC(tcount, "Number of threads to spawn (default: 10)");
55
56 static bool enomem_retry = false;
57 module_param(enomem_retry, bool, 0);
58 MODULE_PARM_DESC(enomem_retry, "Retry insert even if -ENOMEM was returned (default: off)");
59
60 struct test_obj_val {
61         int     id;
62         int     tid;
63 };
64
65 struct test_obj {
66         struct test_obj_val     value;
67         struct rhash_head       node;
68 };
69
70 struct test_obj_rhl {
71         struct test_obj_val     value;
72         struct rhlist_head      list_node;
73 };
74
75 struct thread_data {
76         unsigned int entries;
77         int id;
78         struct task_struct *task;
79         struct test_obj *objs;
80 };
81
82 static u32 my_hashfn(const void *data, u32 len, u32 seed)
83 {
84         const struct test_obj_rhl *obj = data;
85
86         return (obj->value.id % 10);
87 }
88
89 static int my_cmpfn(struct rhashtable_compare_arg *arg, const void *obj)
90 {
91         const struct test_obj_rhl *test_obj = obj;
92         const struct test_obj_val *val = arg->key;
93
94         return test_obj->value.id - val->id;
95 }
96
97 static struct rhashtable_params test_rht_params = {
98         .head_offset = offsetof(struct test_obj, node),
99         .key_offset = offsetof(struct test_obj, value),
100         .key_len = sizeof(struct test_obj_val),
101         .hashfn = jhash,
102 };
103
104 static struct rhashtable_params test_rht_params_dup = {
105         .head_offset = offsetof(struct test_obj_rhl, list_node),
106         .key_offset = offsetof(struct test_obj_rhl, value),
107         .key_len = sizeof(struct test_obj_val),
108         .hashfn = jhash,
109         .obj_hashfn = my_hashfn,
110         .obj_cmpfn = my_cmpfn,
111         .nelem_hint = 128,
112         .automatic_shrinking = false,
113 };
114
115 static atomic_t startup_count;
116 static DECLARE_WAIT_QUEUE_HEAD(startup_wait);
117
118 static int insert_retry(struct rhashtable *ht, struct test_obj *obj,
119                         const struct rhashtable_params params)
120 {
121         int err, retries = -1, enomem_retries = 0;
122
123         do {
124                 retries++;
125                 cond_resched();
126                 err = rhashtable_insert_fast(ht, &obj->node, params);
127                 if (err == -ENOMEM && enomem_retry) {
128                         enomem_retries++;
129                         err = -EBUSY;
130                 }
131         } while (err == -EBUSY);
132
133         if (enomem_retries)
134                 pr_info(" %u insertions retried after -ENOMEM\n",
135                         enomem_retries);
136
137         return err ? : retries;
138 }
139
140 static int __init test_rht_lookup(struct rhashtable *ht, struct test_obj *array,
141                                   unsigned int entries)
142 {
143         unsigned int i;
144
145         for (i = 0; i < entries; i++) {
146                 struct test_obj *obj;
147                 bool expected = !(i % 2);
148                 struct test_obj_val key = {
149                         .id = i,
150                 };
151
152                 if (array[i / 2].value.id == TEST_INSERT_FAIL)
153                         expected = false;
154
155                 obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
156
157                 if (expected && !obj) {
158                         pr_warn("Test failed: Could not find key %u\n", key.id);
159                         return -ENOENT;
160                 } else if (!expected && obj) {
161                         pr_warn("Test failed: Unexpected entry found for key %u\n",
162                                 key.id);
163                         return -EEXIST;
164                 } else if (expected && obj) {
165                         if (obj->value.id != i) {
166                                 pr_warn("Test failed: Lookup value mismatch %u!=%u\n",
167                                         obj->value.id, i);
168                                 return -EINVAL;
169                         }
170                 }
171
172                 cond_resched_rcu();
173         }
174
175         return 0;
176 }
177
178 static void test_bucket_stats(struct rhashtable *ht, unsigned int entries)
179 {
180         unsigned int err, total = 0, chain_len = 0;
181         struct rhashtable_iter hti;
182         struct rhash_head *pos;
183
184         err = rhashtable_walk_init(ht, &hti, GFP_KERNEL);
185         if (err) {
186                 pr_warn("Test failed: allocation error");
187                 return;
188         }
189
190         rhashtable_walk_start(&hti);
191
192         while ((pos = rhashtable_walk_next(&hti))) {
193                 if (PTR_ERR(pos) == -EAGAIN) {
194                         pr_info("Info: encountered resize\n");
195                         chain_len++;
196                         continue;
197                 } else if (IS_ERR(pos)) {
198                         pr_warn("Test failed: rhashtable_walk_next() error: %ld\n",
199                                 PTR_ERR(pos));
200                         break;
201                 }
202
203                 total++;
204         }
205
206         rhashtable_walk_stop(&hti);
207         rhashtable_walk_exit(&hti);
208
209         pr_info("  Traversal complete: counted=%u, nelems=%u, entries=%d, table-jumps=%u\n",
210                 total, atomic_read(&ht->nelems), entries, chain_len);
211
212         if (total != atomic_read(&ht->nelems) || total != entries)
213                 pr_warn("Test failed: Total count mismatch ^^^");
214 }
215
216 static s64 __init test_rhashtable(struct rhashtable *ht, struct test_obj *array,
217                                   unsigned int entries)
218 {
219         struct test_obj *obj;
220         int err;
221         unsigned int i, insert_retries = 0;
222         s64 start, end;
223
224         /*
225          * Insertion Test:
226          * Insert entries into table with all keys even numbers
227          */
228         pr_info("  Adding %d keys\n", entries);
229         start = ktime_get_ns();
230         for (i = 0; i < entries; i++) {
231                 struct test_obj *obj = &array[i];
232
233                 obj->value.id = i * 2;
234                 err = insert_retry(ht, obj, test_rht_params);
235                 if (err > 0)
236                         insert_retries += err;
237                 else if (err)
238                         return err;
239         }
240
241         if (insert_retries)
242                 pr_info("  %u insertions retried due to memory pressure\n",
243                         insert_retries);
244
245         test_bucket_stats(ht, entries);
246         rcu_read_lock();
247         test_rht_lookup(ht, array, entries);
248         rcu_read_unlock();
249
250         test_bucket_stats(ht, entries);
251
252         pr_info("  Deleting %d keys\n", entries);
253         for (i = 0; i < entries; i++) {
254                 struct test_obj_val key = {
255                         .id = i * 2,
256                 };
257
258                 if (array[i].value.id != TEST_INSERT_FAIL) {
259                         obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
260                         BUG_ON(!obj);
261
262                         rhashtable_remove_fast(ht, &obj->node, test_rht_params);
263                 }
264
265                 cond_resched();
266         }
267
268         end = ktime_get_ns();
269         pr_info("  Duration of test: %lld ns\n", end - start);
270
271         return end - start;
272 }
273
274 static struct rhashtable ht;
275 static struct rhltable rhlt;
276
277 static int __init test_rhltable(unsigned int entries)
278 {
279         struct test_obj_rhl *rhl_test_objects;
280         unsigned long *obj_in_table;
281         unsigned int i, j, k;
282         int ret, err;
283
284         if (entries == 0)
285                 entries = 1;
286
287         rhl_test_objects = vzalloc(array_size(entries,
288                                               sizeof(*rhl_test_objects)));
289         if (!rhl_test_objects)
290                 return -ENOMEM;
291
292         ret = -ENOMEM;
293         obj_in_table = vzalloc(array_size(sizeof(unsigned long),
294                                           BITS_TO_LONGS(entries)));
295         if (!obj_in_table)
296                 goto out_free;
297
298         err = rhltable_init(&rhlt, &test_rht_params);
299         if (WARN_ON(err))
300                 goto out_free;
301
302         k = prandom_u32();
303         ret = 0;
304         for (i = 0; i < entries; i++) {
305                 rhl_test_objects[i].value.id = k;
306                 err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node,
307                                       test_rht_params);
308                 if (WARN(err, "error %d on element %d\n", err, i))
309                         break;
310                 if (err == 0)
311                         set_bit(i, obj_in_table);
312         }
313
314         if (err)
315                 ret = err;
316
317         pr_info("test %d add/delete pairs into rhlist\n", entries);
318         for (i = 0; i < entries; i++) {
319                 struct rhlist_head *h, *pos;
320                 struct test_obj_rhl *obj;
321                 struct test_obj_val key = {
322                         .id = k,
323                 };
324                 bool found;
325
326                 rcu_read_lock();
327                 h = rhltable_lookup(&rhlt, &key, test_rht_params);
328                 if (WARN(!h, "key not found during iteration %d of %d", i, entries)) {
329                         rcu_read_unlock();
330                         break;
331                 }
332
333                 if (i) {
334                         j = i - 1;
335                         rhl_for_each_entry_rcu(obj, pos, h, list_node) {
336                                 if (WARN(pos == &rhl_test_objects[j].list_node, "old element found, should be gone"))
337                                         break;
338                         }
339                 }
340
341                 cond_resched_rcu();
342
343                 found = false;
344
345                 rhl_for_each_entry_rcu(obj, pos, h, list_node) {
346                         if (pos == &rhl_test_objects[i].list_node) {
347                                 found = true;
348                                 break;
349                         }
350                 }
351
352                 rcu_read_unlock();
353
354                 if (WARN(!found, "element %d not found", i))
355                         break;
356
357                 err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
358                 WARN(err, "rhltable_remove: err %d for iteration %d\n", err, i);
359                 if (err == 0)
360                         clear_bit(i, obj_in_table);
361         }
362
363         if (ret == 0 && err)
364                 ret = err;
365
366         for (i = 0; i < entries; i++) {
367                 WARN(test_bit(i, obj_in_table), "elem %d allegedly still present", i);
368
369                 err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node,
370                                       test_rht_params);
371                 if (WARN(err, "error %d on element %d\n", err, i))
372                         break;
373                 if (err == 0)
374                         set_bit(i, obj_in_table);
375         }
376
377         pr_info("test %d random rhlist add/delete operations\n", entries);
378         for (j = 0; j < entries; j++) {
379                 u32 i = prandom_u32_max(entries);
380                 u32 prand = prandom_u32();
381
382                 cond_resched();
383
384                 if (prand == 0)
385                         prand = prandom_u32();
386
387                 if (prand & 1) {
388                         prand >>= 1;
389                         continue;
390                 }
391
392                 err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
393                 if (test_bit(i, obj_in_table)) {
394                         clear_bit(i, obj_in_table);
395                         if (WARN(err, "cannot remove element at slot %d", i))
396                                 continue;
397                 } else {
398                         if (WARN(err != -ENOENT, "removed non-existant element %d, error %d not %d",
399                              i, err, -ENOENT))
400                                 continue;
401                 }
402
403                 if (prand & 1) {
404                         prand >>= 1;
405                         continue;
406                 }
407
408                 err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
409                 if (err == 0) {
410                         if (WARN(test_and_set_bit(i, obj_in_table), "succeeded to insert same object %d", i))
411                                 continue;
412                 } else {
413                         if (WARN(!test_bit(i, obj_in_table), "failed to insert object %d", i))
414                                 continue;
415                 }
416
417                 if (prand & 1) {
418                         prand >>= 1;
419                         continue;
420                 }
421
422                 i = prandom_u32_max(entries);
423                 if (test_bit(i, obj_in_table)) {
424                         err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
425                         WARN(err, "cannot remove element at slot %d", i);
426                         if (err == 0)
427                                 clear_bit(i, obj_in_table);
428                 } else {
429                         err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
430                         WARN(err, "failed to insert object %d", i);
431                         if (err == 0)
432                                 set_bit(i, obj_in_table);
433                 }
434         }
435
436         for (i = 0; i < entries; i++) {
437                 cond_resched();
438                 err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
439                 if (test_bit(i, obj_in_table)) {
440                         if (WARN(err, "cannot remove element at slot %d", i))
441                                 continue;
442                 } else {
443                         if (WARN(err != -ENOENT, "removed non-existant element, error %d not %d",
444                                  err, -ENOENT))
445                         continue;
446                 }
447         }
448
449         rhltable_destroy(&rhlt);
450 out_free:
451         vfree(rhl_test_objects);
452         vfree(obj_in_table);
453         return ret;
454 }
455
456 static int __init test_rhashtable_max(struct test_obj *array,
457                                       unsigned int entries)
458 {
459         unsigned int i, insert_retries = 0;
460         int err;
461
462         test_rht_params.max_size = roundup_pow_of_two(entries / 8);
463         err = rhashtable_init(&ht, &test_rht_params);
464         if (err)
465                 return err;
466
467         for (i = 0; i < ht.max_elems; i++) {
468                 struct test_obj *obj = &array[i];
469
470                 obj->value.id = i * 2;
471                 err = insert_retry(&ht, obj, test_rht_params);
472                 if (err > 0)
473                         insert_retries += err;
474                 else if (err)
475                         return err;
476         }
477
478         err = insert_retry(&ht, &array[ht.max_elems], test_rht_params);
479         if (err == -E2BIG) {
480                 err = 0;
481         } else {
482                 pr_info("insert element %u should have failed with %d, got %d\n",
483                                 ht.max_elems, -E2BIG, err);
484                 if (err == 0)
485                         err = -1;
486         }
487
488         rhashtable_destroy(&ht);
489
490         return err;
491 }
492
493 static unsigned int __init print_ht(struct rhltable *rhlt)
494 {
495         struct rhashtable *ht;
496         const struct bucket_table *tbl;
497         char buff[512] = "";
498         unsigned int i, cnt = 0;
499
500         ht = &rhlt->ht;
501         /* Take the mutex to avoid RCU warning */
502         mutex_lock(&ht->mutex);
503         tbl = rht_dereference(ht->tbl, ht);
504         for (i = 0; i < tbl->size; i++) {
505                 struct rhash_head *pos, *next;
506                 struct test_obj_rhl *p;
507
508                 pos = rht_dereference(tbl->buckets[i], ht);
509                 next = !rht_is_a_nulls(pos) ? rht_dereference(pos->next, ht) : NULL;
510
511                 if (!rht_is_a_nulls(pos)) {
512                         sprintf(buff, "%s\nbucket[%d] -> ", buff, i);
513                 }
514
515                 while (!rht_is_a_nulls(pos)) {
516                         struct rhlist_head *list = container_of(pos, struct rhlist_head, rhead);
517                         sprintf(buff, "%s[[", buff);
518                         do {
519                                 pos = &list->rhead;
520                                 list = rht_dereference(list->next, ht);
521                                 p = rht_obj(ht, pos);
522
523                                 sprintf(buff, "%s val %d (tid=%d)%s", buff, p->value.id, p->value.tid,
524                                         list? ", " : " ");
525                                 cnt++;
526                         } while (list);
527
528                         pos = next,
529                         next = !rht_is_a_nulls(pos) ?
530                                 rht_dereference(pos->next, ht) : NULL;
531
532                         sprintf(buff, "%s]]%s", buff, !rht_is_a_nulls(pos) ? " -> " : "");
533                 }
534         }
535         printk(KERN_ERR "\n---- ht: ----%s\n-------------\n", buff);
536         mutex_unlock(&ht->mutex);
537
538         return cnt;
539 }
540
541 static int __init test_insert_dup(struct test_obj_rhl *rhl_test_objects,
542                                   int cnt, bool slow)
543 {
544         struct rhltable *rhlt;
545         unsigned int i, ret;
546         const char *key;
547         int err = 0;
548
549         rhlt = kmalloc(sizeof(*rhlt), GFP_KERNEL);
550         if (WARN_ON(!rhlt))
551                 return -EINVAL;
552
553         err = rhltable_init(rhlt, &test_rht_params_dup);
554         if (WARN_ON(err)) {
555                 kfree(rhlt);
556                 return err;
557         }
558
559         for (i = 0; i < cnt; i++) {
560                 rhl_test_objects[i].value.tid = i;
561                 key = rht_obj(&rhlt->ht, &rhl_test_objects[i].list_node.rhead);
562                 key += test_rht_params_dup.key_offset;
563
564                 if (slow) {
565                         err = PTR_ERR(rhashtable_insert_slow(&rhlt->ht, key,
566                                                              &rhl_test_objects[i].list_node.rhead));
567                         if (err == -EAGAIN)
568                                 err = 0;
569                 } else
570                         err = rhltable_insert(rhlt,
571                                               &rhl_test_objects[i].list_node,
572                                               test_rht_params_dup);
573                 if (WARN(err, "error %d on element %d/%d (%s)\n", err, i, cnt, slow? "slow" : "fast"))
574                         goto skip_print;
575         }
576
577         ret = print_ht(rhlt);
578         WARN(ret != cnt, "missing rhltable elements (%d != %d, %s)\n", ret, cnt, slow? "slow" : "fast");
579
580 skip_print:
581         rhltable_destroy(rhlt);
582         kfree(rhlt);
583
584         return 0;
585 }
586
587 static int __init test_insert_duplicates_run(void)
588 {
589         struct test_obj_rhl rhl_test_objects[3] = {};
590
591         pr_info("test inserting duplicates\n");
592
593         /* two different values that map to same bucket */
594         rhl_test_objects[0].value.id = 1;
595         rhl_test_objects[1].value.id = 21;
596
597         /* and another duplicate with same as [0] value
598          * which will be second on the bucket list */
599         rhl_test_objects[2].value.id = rhl_test_objects[0].value.id;
600
601         test_insert_dup(rhl_test_objects, 2, false);
602         test_insert_dup(rhl_test_objects, 3, false);
603         test_insert_dup(rhl_test_objects, 2, true);
604         test_insert_dup(rhl_test_objects, 3, true);
605
606         return 0;
607 }
608
609 static int thread_lookup_test(struct thread_data *tdata)
610 {
611         unsigned int entries = tdata->entries;
612         int i, err = 0;
613
614         for (i = 0; i < entries; i++) {
615                 struct test_obj *obj;
616                 struct test_obj_val key = {
617                         .id = i,
618                         .tid = tdata->id,
619                 };
620
621                 obj = rhashtable_lookup_fast(&ht, &key, test_rht_params);
622                 if (obj && (tdata->objs[i].value.id == TEST_INSERT_FAIL)) {
623                         pr_err("  found unexpected object %d-%d\n", key.tid, key.id);
624                         err++;
625                 } else if (!obj && (tdata->objs[i].value.id != TEST_INSERT_FAIL)) {
626                         pr_err("  object %d-%d not found!\n", key.tid, key.id);
627                         err++;
628                 } else if (obj && memcmp(&obj->value, &key, sizeof(key))) {
629                         pr_err("  wrong object returned (got %d-%d, expected %d-%d)\n",
630                                obj->value.tid, obj->value.id, key.tid, key.id);
631                         err++;
632                 }
633
634                 cond_resched();
635         }
636         return err;
637 }
638
639 static int threadfunc(void *data)
640 {
641         int i, step, err = 0, insert_retries = 0;
642         struct thread_data *tdata = data;
643
644         if (atomic_dec_and_test(&startup_count))
645                 wake_up(&startup_wait);
646         if (wait_event_interruptible(startup_wait, atomic_read(&startup_count) == -1)) {
647                 pr_err("  thread[%d]: interrupted\n", tdata->id);
648                 goto out;
649         }
650
651         for (i = 0; i < tdata->entries; i++) {
652                 tdata->objs[i].value.id = i;
653                 tdata->objs[i].value.tid = tdata->id;
654                 err = insert_retry(&ht, &tdata->objs[i], test_rht_params);
655                 if (err > 0) {
656                         insert_retries += err;
657                 } else if (err) {
658                         pr_err("  thread[%d]: rhashtable_insert_fast failed\n",
659                                tdata->id);
660                         goto out;
661                 }
662         }
663         if (insert_retries)
664                 pr_info("  thread[%d]: %u insertions retried due to memory pressure\n",
665                         tdata->id, insert_retries);
666
667         err = thread_lookup_test(tdata);
668         if (err) {
669                 pr_err("  thread[%d]: rhashtable_lookup_test failed\n",
670                        tdata->id);
671                 goto out;
672         }
673
674         for (step = 10; step > 0; step--) {
675                 for (i = 0; i < tdata->entries; i += step) {
676                         if (tdata->objs[i].value.id == TEST_INSERT_FAIL)
677                                 continue;
678                         err = rhashtable_remove_fast(&ht, &tdata->objs[i].node,
679                                                      test_rht_params);
680                         if (err) {
681                                 pr_err("  thread[%d]: rhashtable_remove_fast failed\n",
682                                        tdata->id);
683                                 goto out;
684                         }
685                         tdata->objs[i].value.id = TEST_INSERT_FAIL;
686
687                         cond_resched();
688                 }
689                 err = thread_lookup_test(tdata);
690                 if (err) {
691                         pr_err("  thread[%d]: rhashtable_lookup_test (2) failed\n",
692                                tdata->id);
693                         goto out;
694                 }
695         }
696 out:
697         while (!kthread_should_stop()) {
698                 set_current_state(TASK_INTERRUPTIBLE);
699                 schedule();
700         }
701         return err;
702 }
703
704 static int __init test_rht_init(void)
705 {
706         unsigned int entries;
707         int i, err, started_threads = 0, failed_threads = 0;
708         u64 total_time = 0;
709         struct thread_data *tdata;
710         struct test_obj *objs;
711
712         if (parm_entries < 0)
713                 parm_entries = 1;
714
715         entries = min(parm_entries, MAX_ENTRIES);
716
717         test_rht_params.automatic_shrinking = shrinking;
718         test_rht_params.max_size = max_size ? : roundup_pow_of_two(entries);
719         test_rht_params.nelem_hint = size;
720
721         objs = vzalloc(array_size(sizeof(struct test_obj),
722                                   test_rht_params.max_size + 1));
723         if (!objs)
724                 return -ENOMEM;
725
726         pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n",
727                 size, max_size, shrinking);
728
729         for (i = 0; i < runs; i++) {
730                 s64 time;
731
732                 pr_info("Test %02d:\n", i);
733                 memset(objs, 0, test_rht_params.max_size * sizeof(struct test_obj));
734
735                 err = rhashtable_init(&ht, &test_rht_params);
736                 if (err < 0) {
737                         pr_warn("Test failed: Unable to initialize hashtable: %d\n",
738                                 err);
739                         continue;
740                 }
741
742                 time = test_rhashtable(&ht, objs, entries);
743                 rhashtable_destroy(&ht);
744                 if (time < 0) {
745                         vfree(objs);
746                         pr_warn("Test failed: return code %lld\n", time);
747                         return -EINVAL;
748                 }
749
750                 total_time += time;
751         }
752
753         pr_info("test if its possible to exceed max_size %d: %s\n",
754                         test_rht_params.max_size, test_rhashtable_max(objs, entries) == 0 ?
755                         "no, ok" : "YES, failed");
756         vfree(objs);
757
758         do_div(total_time, runs);
759         pr_info("Average test time: %llu\n", total_time);
760
761         test_insert_duplicates_run();
762
763         if (!tcount)
764                 return 0;
765
766         pr_info("Testing concurrent rhashtable access from %d threads\n",
767                 tcount);
768         atomic_set(&startup_count, tcount);
769         tdata = vzalloc(array_size(tcount, sizeof(struct thread_data)));
770         if (!tdata)
771                 return -ENOMEM;
772         objs  = vzalloc(array3_size(sizeof(struct test_obj), tcount, entries));
773         if (!objs) {
774                 vfree(tdata);
775                 return -ENOMEM;
776         }
777
778         test_rht_params.max_size = max_size ? :
779                                    roundup_pow_of_two(tcount * entries);
780         err = rhashtable_init(&ht, &test_rht_params);
781         if (err < 0) {
782                 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
783                         err);
784                 vfree(tdata);
785                 vfree(objs);
786                 return -EINVAL;
787         }
788         for (i = 0; i < tcount; i++) {
789                 tdata[i].id = i;
790                 tdata[i].entries = entries;
791                 tdata[i].objs = objs + i * entries;
792                 tdata[i].task = kthread_run(threadfunc, &tdata[i],
793                                             "rhashtable_thrad[%d]", i);
794                 if (IS_ERR(tdata[i].task)) {
795                         pr_err(" kthread_run failed for thread %d\n", i);
796                         atomic_dec(&startup_count);
797                 } else {
798                         started_threads++;
799                 }
800         }
801         if (wait_event_interruptible(startup_wait, atomic_read(&startup_count) == 0))
802                 pr_err("  wait_event interruptible failed\n");
803         /* count is 0 now, set it to -1 and wake up all threads together */
804         atomic_dec(&startup_count);
805         wake_up_all(&startup_wait);
806         for (i = 0; i < tcount; i++) {
807                 if (IS_ERR(tdata[i].task))
808                         continue;
809                 if ((err = kthread_stop(tdata[i].task))) {
810                         pr_warn("Test failed: thread %d returned: %d\n",
811                                 i, err);
812                         failed_threads++;
813                 }
814         }
815         rhashtable_destroy(&ht);
816         vfree(tdata);
817         vfree(objs);
818
819         /*
820          * rhltable_remove is very expensive, default values can cause test
821          * to run for 2 minutes or more,  use a smaller number instead.
822          */
823         err = test_rhltable(entries / 16);
824         pr_info("Started %d threads, %d failed, rhltable test returns %d\n",
825                 started_threads, failed_threads, err);
826         return 0;
827 }
828
829 static void __exit test_rht_exit(void)
830 {
831 }
832
833 module_init(test_rht_init);
834 module_exit(test_rht_exit);
835
836 MODULE_LICENSE("GPL v2");