1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Resizable, Scalable, Concurrent Hash Table
4 *
5 * Copyright (c) 2014-2015 Thomas Graf <tgraf@suug.ch>
6 * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
7 */
8
9/**************************************************************************
10 * Self Test
11 **************************************************************************/
12
13#include <linux/init.h>
14#include <linux/jhash.h>
15#include <linux/kernel.h>
16#include <linux/kthread.h>
17#include <linux/module.h>
18#include <linux/rcupdate.h>
19#include <linux/rhashtable.h>
20#include <linux/slab.h>
21#include <linux/sched.h>
22#include <linux/random.h>
23#include <linux/vmalloc.h>
24#include <linux/wait.h>
25
26#define MAX_ENTRIES 1000000
27#define TEST_INSERT_FAIL INT_MAX
28
29static int parm_entries = 50000;
30module_param(parm_entries, int, 0);
31MODULE_PARM_DESC(parm_entries, "Number of entries to add (default: 50000)");
32
33static int runs = 4;
34module_param(runs, int, 0);
35MODULE_PARM_DESC(runs, "Number of test runs per variant (default: 4)");
36
37static int max_size = 0;
38module_param(max_size, int, 0);
39MODULE_PARM_DESC(max_size, "Maximum table size (default: calculated)");
40
41static bool shrinking = false;
42module_param(shrinking, bool, 0);
43MODULE_PARM_DESC(shrinking, "Enable automatic shrinking (default: off)");
44
45static int size = 8;
46module_param(size, int, 0);
47MODULE_PARM_DESC(size, "Initial size hint of table (default: 8)");
48
49static int tcount = 10;
50module_param(tcount, int, 0);
51MODULE_PARM_DESC(tcount, "Number of threads to spawn (default: 10)");
52
53static bool enomem_retry = false;
54module_param(enomem_retry, bool, 0);
55MODULE_PARM_DESC(enomem_retry, "Retry insert even if -ENOMEM was returned (default: off)");
56
57struct test_obj_val {
58 int id;
59 int tid;
60};
61
62struct test_obj {
63 struct test_obj_val value;
64 struct rhash_head node;
65};
66
67struct test_obj_rhl {
68 struct test_obj_val value;
69 struct rhlist_head list_node;
70};
71
72struct thread_data {
73 unsigned int entries;
74 int id;
75 struct task_struct *task;
76 struct test_obj *objs;
77};
78
79static u32 my_hashfn(const void *data, u32 len, u32 seed)
80{
81 const struct test_obj_rhl *obj = data;
82
83 return (obj->value.id % 10);
84}
85
86static int my_cmpfn(struct rhashtable_compare_arg *arg, const void *obj)
87{
88 const struct test_obj_rhl *test_obj = obj;
89 const struct test_obj_val *val = arg->key;
90
91 return test_obj->value.id - val->id;
92}
93
94static struct rhashtable_params test_rht_params = {
95 .head_offset = offsetof(struct test_obj, node),
96 .key_offset = offsetof(struct test_obj, value),
97 .key_len = sizeof(struct test_obj_val),
98 .hashfn = jhash,
99};
100
101static struct rhashtable_params test_rht_params_dup = {
102 .head_offset = offsetof(struct test_obj_rhl, list_node),
103 .key_offset = offsetof(struct test_obj_rhl, value),
104 .key_len = sizeof(struct test_obj_val),
105 .hashfn = jhash,
106 .obj_hashfn = my_hashfn,
107 .obj_cmpfn = my_cmpfn,
108 .nelem_hint = 128,
109 .automatic_shrinking = false,
110};
111
112static atomic_t startup_count;
113static DECLARE_WAIT_QUEUE_HEAD(startup_wait);
114
115static int insert_retry(struct rhashtable *ht, struct test_obj *obj,
116 const struct rhashtable_params params)
117{
118 int err, retries = -1, enomem_retries = 0;
119
120 do {
121 retries++;
122 cond_resched();
123 err = rhashtable_insert_fast(ht, obj: &obj->node, params);
124 if (err == -ENOMEM && enomem_retry) {
125 enomem_retries++;
126 err = -EBUSY;
127 }
128 } while (err == -EBUSY);
129
130 if (enomem_retries)
131 pr_info(" %u insertions retried after -ENOMEM\n",
132 enomem_retries);
133
134 return err ? : retries;
135}
136
137static int __init test_rht_lookup(struct rhashtable *ht, struct test_obj *array,
138 unsigned int entries)
139{
140 unsigned int i;
141
142 for (i = 0; i < entries; i++) {
143 struct test_obj *obj;
144 bool expected = !(i % 2);
145 struct test_obj_val key = {
146 .id = i,
147 };
148
149 if (array[i / 2].value.id == TEST_INSERT_FAIL)
150 expected = false;
151
152 obj = rhashtable_lookup_fast(ht, key: &key, params: test_rht_params);
153
154 if (expected && !obj) {
155 pr_warn("Test failed: Could not find key %u\n", key.id);
156 return -ENOENT;
157 } else if (!expected && obj) {
158 pr_warn("Test failed: Unexpected entry found for key %u\n",
159 key.id);
160 return -EEXIST;
161 } else if (expected && obj) {
162 if (obj->value.id != i) {
163 pr_warn("Test failed: Lookup value mismatch %u!=%u\n",
164 obj->value.id, i);
165 return -EINVAL;
166 }
167 }
168
169 cond_resched_rcu();
170 }
171
172 return 0;
173}
174
175static void test_bucket_stats(struct rhashtable *ht, unsigned int entries)
176{
177 unsigned int total = 0, chain_len = 0;
178 struct rhashtable_iter hti;
179 struct rhash_head *pos;
180
181 rhashtable_walk_enter(ht, iter: &hti);
182 rhashtable_walk_start(iter: &hti);
183
184 while ((pos = rhashtable_walk_next(iter: &hti))) {
185 if (PTR_ERR(ptr: pos) == -EAGAIN) {
186 pr_info("Info: encountered resize\n");
187 chain_len++;
188 continue;
189 } else if (IS_ERR(ptr: pos)) {
190 pr_warn("Test failed: rhashtable_walk_next() error: %ld\n",
191 PTR_ERR(pos));
192 break;
193 }
194
195 total++;
196 }
197
198 rhashtable_walk_stop(iter: &hti);
199 rhashtable_walk_exit(iter: &hti);
200
201 pr_info(" Traversal complete: counted=%u, nelems=%u, entries=%d, table-jumps=%u\n",
202 total, atomic_read(&ht->nelems), entries, chain_len);
203
204 if (total != atomic_read(v: &ht->nelems) || total != entries)
205 pr_warn("Test failed: Total count mismatch ^^^");
206}
207
208static s64 __init test_rhashtable(struct rhashtable *ht, struct test_obj *array,
209 unsigned int entries)
210{
211 struct test_obj *obj;
212 int err;
213 unsigned int i, insert_retries = 0;
214 s64 start, end;
215
216 /*
217 * Insertion Test:
218 * Insert entries into table with all keys even numbers
219 */
220 pr_info(" Adding %d keys\n", entries);
221 start = ktime_get_ns();
222 for (i = 0; i < entries; i++) {
223 struct test_obj *obj = &array[i];
224
225 obj->value.id = i * 2;
226 err = insert_retry(ht, obj, params: test_rht_params);
227 if (err > 0)
228 insert_retries += err;
229 else if (err)
230 return err;
231 }
232
233 if (insert_retries)
234 pr_info(" %u insertions retried due to memory pressure\n",
235 insert_retries);
236
237 test_bucket_stats(ht, entries);
238 rcu_read_lock();
239 test_rht_lookup(ht, array, entries);
240 rcu_read_unlock();
241
242 test_bucket_stats(ht, entries);
243
244 pr_info(" Deleting %d keys\n", entries);
245 for (i = 0; i < entries; i++) {
246 struct test_obj_val key = {
247 .id = i * 2,
248 };
249
250 if (array[i].value.id != TEST_INSERT_FAIL) {
251 obj = rhashtable_lookup_fast(ht, key: &key, params: test_rht_params);
252 BUG_ON(!obj);
253
254 rhashtable_remove_fast(ht, obj: &obj->node, params: test_rht_params);
255 }
256
257 cond_resched();
258 }
259
260 end = ktime_get_ns();
261 pr_info(" Duration of test: %lld ns\n", end - start);
262
263 return end - start;
264}
265
266static struct rhashtable ht;
267static struct rhltable rhlt;
268
269static int __init test_rhltable(unsigned int entries)
270{
271 struct test_obj_rhl *rhl_test_objects;
272 unsigned long *obj_in_table;
273 unsigned int i, j, k;
274 int ret, err;
275
276 if (entries == 0)
277 entries = 1;
278
279 rhl_test_objects = vzalloc(array_size(entries,
280 sizeof(*rhl_test_objects)));
281 if (!rhl_test_objects)
282 return -ENOMEM;
283
284 ret = -ENOMEM;
285 obj_in_table = vzalloc(array_size(sizeof(unsigned long),
286 BITS_TO_LONGS(entries)));
287 if (!obj_in_table)
288 goto out_free;
289
290 err = rhltable_init(hlt: &rhlt, params: &test_rht_params);
291 if (WARN_ON(err))
292 goto out_free;
293
294 k = get_random_u32();
295 ret = 0;
296 for (i = 0; i < entries; i++) {
297 rhl_test_objects[i].value.id = k;
298 err = rhltable_insert(hlt: &rhlt, list: &rhl_test_objects[i].list_node,
299 params: test_rht_params);
300 if (WARN(err, "error %d on element %d\n", err, i))
301 break;
302 if (err == 0)
303 set_bit(nr: i, addr: obj_in_table);
304 }
305
306 if (err)
307 ret = err;
308
309 pr_info("test %d add/delete pairs into rhlist\n", entries);
310 for (i = 0; i < entries; i++) {
311 struct rhlist_head *h, *pos;
312 struct test_obj_rhl *obj;
313 struct test_obj_val key = {
314 .id = k,
315 };
316 bool found;
317
318 rcu_read_lock();
319 h = rhltable_lookup(hlt: &rhlt, key: &key, params: test_rht_params);
320 if (WARN(!h, "key not found during iteration %d of %d", i, entries)) {
321 rcu_read_unlock();
322 break;
323 }
324
325 if (i) {
326 j = i - 1;
327 rhl_for_each_entry_rcu(obj, pos, h, list_node) {
328 if (WARN(pos == &rhl_test_objects[j].list_node, "old element found, should be gone"))
329 break;
330 }
331 }
332
333 cond_resched_rcu();
334
335 found = false;
336
337 rhl_for_each_entry_rcu(obj, pos, h, list_node) {
338 if (pos == &rhl_test_objects[i].list_node) {
339 found = true;
340 break;
341 }
342 }
343
344 rcu_read_unlock();
345
346 if (WARN(!found, "element %d not found", i))
347 break;
348
349 err = rhltable_remove(hlt: &rhlt, list: &rhl_test_objects[i].list_node, params: test_rht_params);
350 WARN(err, "rhltable_remove: err %d for iteration %d\n", err, i);
351 if (err == 0)
352 clear_bit(nr: i, addr: obj_in_table);
353 }
354
355 if (ret == 0 && err)
356 ret = err;
357
358 for (i = 0; i < entries; i++) {
359 WARN(test_bit(i, obj_in_table), "elem %d allegedly still present", i);
360
361 err = rhltable_insert(hlt: &rhlt, list: &rhl_test_objects[i].list_node,
362 params: test_rht_params);
363 if (WARN(err, "error %d on element %d\n", err, i))
364 break;
365 if (err == 0)
366 set_bit(nr: i, addr: obj_in_table);
367 }
368
369 pr_info("test %d random rhlist add/delete operations\n", entries);
370 for (j = 0; j < entries; j++) {
371 u32 i = get_random_u32_below(ceil: entries);
372 u32 prand = get_random_u32_below(ceil: 4);
373
374 cond_resched();
375
376 err = rhltable_remove(hlt: &rhlt, list: &rhl_test_objects[i].list_node, params: test_rht_params);
377 if (test_bit(i, obj_in_table)) {
378 clear_bit(nr: i, addr: obj_in_table);
379 if (WARN(err, "cannot remove element at slot %d", i))
380 continue;
381 } else {
382 if (WARN(err != -ENOENT, "removed non-existent element %d, error %d not %d",
383 i, err, -ENOENT))
384 continue;
385 }
386
387 if (prand & 1) {
388 err = rhltable_insert(hlt: &rhlt, list: &rhl_test_objects[i].list_node, params: test_rht_params);
389 if (err == 0) {
390 if (WARN(test_and_set_bit(i, obj_in_table), "succeeded to insert same object %d", i))
391 continue;
392 } else {
393 if (WARN(!test_bit(i, obj_in_table), "failed to insert object %d", i))
394 continue;
395 }
396 }
397
398 if (prand & 2) {
399 i = get_random_u32_below(ceil: entries);
400 if (test_bit(i, obj_in_table)) {
401 err = rhltable_remove(hlt: &rhlt, list: &rhl_test_objects[i].list_node, params: test_rht_params);
402 WARN(err, "cannot remove element at slot %d", i);
403 if (err == 0)
404 clear_bit(nr: i, addr: obj_in_table);
405 } else {
406 err = rhltable_insert(hlt: &rhlt, list: &rhl_test_objects[i].list_node, params: test_rht_params);
407 WARN(err, "failed to insert object %d", i);
408 if (err == 0)
409 set_bit(nr: i, addr: obj_in_table);
410 }
411 }
412 }
413
414 for (i = 0; i < entries; i++) {
415 cond_resched();
416 err = rhltable_remove(hlt: &rhlt, list: &rhl_test_objects[i].list_node, params: test_rht_params);
417 if (test_bit(i, obj_in_table)) {
418 if (WARN(err, "cannot remove element at slot %d", i))
419 continue;
420 } else {
421 if (WARN(err != -ENOENT, "removed non-existent element, error %d not %d",
422 err, -ENOENT))
423 continue;
424 }
425 }
426
427 rhltable_destroy(hlt: &rhlt);
428out_free:
429 vfree(addr: rhl_test_objects);
430 vfree(addr: obj_in_table);
431 return ret;
432}
433
434static int __init test_rhashtable_max(struct test_obj *array,
435 unsigned int entries)
436{
437 unsigned int i;
438 int err;
439
440 test_rht_params.max_size = roundup_pow_of_two(entries / 8);
441 err = rhashtable_init(ht: &ht, params: &test_rht_params);
442 if (err)
443 return err;
444
445 for (i = 0; i < ht.max_elems; i++) {
446 struct test_obj *obj = &array[i];
447
448 obj->value.id = i * 2;
449 err = insert_retry(ht: &ht, obj, params: test_rht_params);
450 if (err < 0)
451 return err;
452 }
453
454 err = insert_retry(ht: &ht, obj: &array[ht.max_elems], params: test_rht_params);
455 if (err == -E2BIG) {
456 err = 0;
457 } else {
458 pr_info("insert element %u should have failed with %d, got %d\n",
459 ht.max_elems, -E2BIG, err);
460 if (err == 0)
461 err = -1;
462 }
463
464 rhashtable_destroy(ht: &ht);
465
466 return err;
467}
468
469static unsigned int __init print_ht(struct rhltable *rhlt)
470{
471 struct rhashtable *ht;
472 const struct bucket_table *tbl;
473 char buff[512] = "";
474 int offset = 0;
475 unsigned int i, cnt = 0;
476
477 ht = &rhlt->ht;
478 /* Take the mutex to avoid RCU warning */
479 mutex_lock(&ht->mutex);
480 tbl = rht_dereference(ht->tbl, ht);
481 for (i = 0; i < tbl->size; i++) {
482 struct rhash_head *pos, *next;
483 struct test_obj_rhl *p;
484
485 pos = rht_ptr_exclusive(bkt: tbl->buckets + i);
486 next = !rht_is_a_nulls(ptr: pos) ? rht_dereference(pos->next, ht) : NULL;
487
488 if (!rht_is_a_nulls(ptr: pos)) {
489 offset += sprintf(buf: buff + offset, fmt: "\nbucket[%d] -> ", i);
490 }
491
492 while (!rht_is_a_nulls(ptr: pos)) {
493 struct rhlist_head *list = container_of(pos, struct rhlist_head, rhead);
494 offset += sprintf(buf: buff + offset, fmt: "[[");
495 do {
496 pos = &list->rhead;
497 list = rht_dereference(list->next, ht);
498 p = rht_obj(ht, he: pos);
499
500 offset += sprintf(buf: buff + offset, fmt: " val %d (tid=%d)%s", p->value.id, p->value.tid,
501 list? ", " : " ");
502 cnt++;
503 } while (list);
504
505 pos = next,
506 next = !rht_is_a_nulls(ptr: pos) ?
507 rht_dereference(pos->next, ht) : NULL;
508
509 offset += sprintf(buf: buff + offset, fmt: "]]%s", !rht_is_a_nulls(ptr: pos) ? " -> " : "");
510 }
511 }
512 printk(KERN_ERR "\n---- ht: ----%s\n-------------\n", buff);
513 mutex_unlock(lock: &ht->mutex);
514
515 return cnt;
516}
517
518static int __init test_insert_dup(struct test_obj_rhl *rhl_test_objects,
519 int cnt, bool slow)
520{
521 struct rhltable *rhlt;
522 unsigned int i, ret;
523 const char *key;
524 int err = 0;
525
526 rhlt = kmalloc(size: sizeof(*rhlt), GFP_KERNEL);
527 if (WARN_ON(!rhlt))
528 return -EINVAL;
529
530 err = rhltable_init(hlt: rhlt, params: &test_rht_params_dup);
531 if (WARN_ON(err)) {
532 kfree(objp: rhlt);
533 return err;
534 }
535
536 for (i = 0; i < cnt; i++) {
537 rhl_test_objects[i].value.tid = i;
538 key = rht_obj(ht: &rhlt->ht, he: &rhl_test_objects[i].list_node.rhead);
539 key += test_rht_params_dup.key_offset;
540
541 if (slow) {
542 err = PTR_ERR(ptr: rhashtable_insert_slow(ht: &rhlt->ht, key,
543 obj: &rhl_test_objects[i].list_node.rhead));
544 if (err == -EAGAIN)
545 err = 0;
546 } else
547 err = rhltable_insert(hlt: rhlt,
548 list: &rhl_test_objects[i].list_node,
549 params: test_rht_params_dup);
550 if (WARN(err, "error %d on element %d/%d (%s)\n", err, i, cnt, slow? "slow" : "fast"))
551 goto skip_print;
552 }
553
554 ret = print_ht(rhlt);
555 WARN(ret != cnt, "missing rhltable elements (%d != %d, %s)\n", ret, cnt, slow? "slow" : "fast");
556
557skip_print:
558 rhltable_destroy(hlt: rhlt);
559 kfree(objp: rhlt);
560
561 return 0;
562}
563
564static int __init test_insert_duplicates_run(void)
565{
566 struct test_obj_rhl rhl_test_objects[3] = {};
567
568 pr_info("test inserting duplicates\n");
569
570 /* two different values that map to same bucket */
571 rhl_test_objects[0].value.id = 1;
572 rhl_test_objects[1].value.id = 21;
573
574 /* and another duplicate with same as [0] value
575 * which will be second on the bucket list */
576 rhl_test_objects[2].value.id = rhl_test_objects[0].value.id;
577
578 test_insert_dup(rhl_test_objects, cnt: 2, slow: false);
579 test_insert_dup(rhl_test_objects, cnt: 3, slow: false);
580 test_insert_dup(rhl_test_objects, cnt: 2, slow: true);
581 test_insert_dup(rhl_test_objects, cnt: 3, slow: true);
582
583 return 0;
584}
585
586static int thread_lookup_test(struct thread_data *tdata)
587{
588 unsigned int entries = tdata->entries;
589 int i, err = 0;
590
591 for (i = 0; i < entries; i++) {
592 struct test_obj *obj;
593 struct test_obj_val key = {
594 .id = i,
595 .tid = tdata->id,
596 };
597
598 obj = rhashtable_lookup_fast(ht: &ht, key: &key, params: test_rht_params);
599 if (obj && (tdata->objs[i].value.id == TEST_INSERT_FAIL)) {
600 pr_err(" found unexpected object %d-%d\n", key.tid, key.id);
601 err++;
602 } else if (!obj && (tdata->objs[i].value.id != TEST_INSERT_FAIL)) {
603 pr_err(" object %d-%d not found!\n", key.tid, key.id);
604 err++;
605 } else if (obj && memcmp(p: &obj->value, q: &key, size: sizeof(key))) {
606 pr_err(" wrong object returned (got %d-%d, expected %d-%d)\n",
607 obj->value.tid, obj->value.id, key.tid, key.id);
608 err++;
609 }
610
611 cond_resched();
612 }
613 return err;
614}
615
616static int threadfunc(void *data)
617{
618 int i, step, err = 0, insert_retries = 0;
619 struct thread_data *tdata = data;
620
621 if (atomic_dec_and_test(v: &startup_count))
622 wake_up(&startup_wait);
623 if (wait_event_interruptible(startup_wait, atomic_read(&startup_count) == -1)) {
624 pr_err(" thread[%d]: interrupted\n", tdata->id);
625 goto out;
626 }
627
628 for (i = 0; i < tdata->entries; i++) {
629 tdata->objs[i].value.id = i;
630 tdata->objs[i].value.tid = tdata->id;
631 err = insert_retry(ht: &ht, obj: &tdata->objs[i], params: test_rht_params);
632 if (err > 0) {
633 insert_retries += err;
634 } else if (err) {
635 pr_err(" thread[%d]: rhashtable_insert_fast failed\n",
636 tdata->id);
637 goto out;
638 }
639 }
640 if (insert_retries)
641 pr_info(" thread[%d]: %u insertions retried due to memory pressure\n",
642 tdata->id, insert_retries);
643
644 err = thread_lookup_test(tdata);
645 if (err) {
646 pr_err(" thread[%d]: rhashtable_lookup_test failed\n",
647 tdata->id);
648 goto out;
649 }
650
651 for (step = 10; step > 0; step--) {
652 for (i = 0; i < tdata->entries; i += step) {
653 if (tdata->objs[i].value.id == TEST_INSERT_FAIL)
654 continue;
655 err = rhashtable_remove_fast(ht: &ht, obj: &tdata->objs[i].node,
656 params: test_rht_params);
657 if (err) {
658 pr_err(" thread[%d]: rhashtable_remove_fast failed\n",
659 tdata->id);
660 goto out;
661 }
662 tdata->objs[i].value.id = TEST_INSERT_FAIL;
663
664 cond_resched();
665 }
666 err = thread_lookup_test(tdata);
667 if (err) {
668 pr_err(" thread[%d]: rhashtable_lookup_test (2) failed\n",
669 tdata->id);
670 goto out;
671 }
672 }
673out:
674 while (!kthread_should_stop()) {
675 set_current_state(TASK_INTERRUPTIBLE);
676 schedule();
677 }
678 return err;
679}
680
681static int __init test_rht_init(void)
682{
683 unsigned int entries;
684 int i, err, started_threads = 0, failed_threads = 0;
685 u64 total_time = 0;
686 struct thread_data *tdata;
687 struct test_obj *objs;
688
689 if (parm_entries < 0)
690 parm_entries = 1;
691
692 entries = min(parm_entries, MAX_ENTRIES);
693
694 test_rht_params.automatic_shrinking = shrinking;
695 test_rht_params.max_size = max_size ? : roundup_pow_of_two(entries);
696 test_rht_params.nelem_hint = size;
697
698 objs = vzalloc(array_size(sizeof(struct test_obj),
699 test_rht_params.max_size + 1));
700 if (!objs)
701 return -ENOMEM;
702
703 pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n",
704 size, max_size, shrinking);
705
706 for (i = 0; i < runs; i++) {
707 s64 time;
708
709 pr_info("Test %02d:\n", i);
710 memset(objs, 0, test_rht_params.max_size * sizeof(struct test_obj));
711
712 err = rhashtable_init(ht: &ht, params: &test_rht_params);
713 if (err < 0) {
714 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
715 err);
716 continue;
717 }
718
719 time = test_rhashtable(ht: &ht, array: objs, entries);
720 rhashtable_destroy(ht: &ht);
721 if (time < 0) {
722 vfree(addr: objs);
723 pr_warn("Test failed: return code %lld\n", time);
724 return -EINVAL;
725 }
726
727 total_time += time;
728 }
729
730 pr_info("test if its possible to exceed max_size %d: %s\n",
731 test_rht_params.max_size, test_rhashtable_max(objs, entries) == 0 ?
732 "no, ok" : "YES, failed");
733 vfree(addr: objs);
734
735 do_div(total_time, runs);
736 pr_info("Average test time: %llu\n", total_time);
737
738 test_insert_duplicates_run();
739
740 if (!tcount)
741 return 0;
742
743 pr_info("Testing concurrent rhashtable access from %d threads\n",
744 tcount);
745 atomic_set(v: &startup_count, i: tcount);
746 tdata = vzalloc(array_size(tcount, sizeof(struct thread_data)));
747 if (!tdata)
748 return -ENOMEM;
749 objs = vzalloc(array3_size(sizeof(struct test_obj), tcount, entries));
750 if (!objs) {
751 vfree(addr: tdata);
752 return -ENOMEM;
753 }
754
755 test_rht_params.max_size = max_size ? :
756 roundup_pow_of_two(tcount * entries);
757 err = rhashtable_init(ht: &ht, params: &test_rht_params);
758 if (err < 0) {
759 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
760 err);
761 vfree(addr: tdata);
762 vfree(addr: objs);
763 return -EINVAL;
764 }
765 for (i = 0; i < tcount; i++) {
766 tdata[i].id = i;
767 tdata[i].entries = entries;
768 tdata[i].objs = objs + i * entries;
769 tdata[i].task = kthread_run(threadfunc, &tdata[i],
770 "rhashtable_thrad[%d]", i);
771 if (IS_ERR(ptr: tdata[i].task)) {
772 pr_err(" kthread_run failed for thread %d\n", i);
773 atomic_dec(v: &startup_count);
774 } else {
775 started_threads++;
776 }
777 }
778 if (wait_event_interruptible(startup_wait, atomic_read(&startup_count) == 0))
779 pr_err(" wait_event interruptible failed\n");
780 /* count is 0 now, set it to -1 and wake up all threads together */
781 atomic_dec(v: &startup_count);
782 wake_up_all(&startup_wait);
783 for (i = 0; i < tcount; i++) {
784 if (IS_ERR(ptr: tdata[i].task))
785 continue;
786 if ((err = kthread_stop(k: tdata[i].task))) {
787 pr_warn("Test failed: thread %d returned: %d\n",
788 i, err);
789 failed_threads++;
790 }
791 }
792 rhashtable_destroy(ht: &ht);
793 vfree(addr: tdata);
794 vfree(addr: objs);
795
796 /*
797 * rhltable_remove is very expensive, default values can cause test
798 * to run for 2 minutes or more, use a smaller number instead.
799 */
800 err = test_rhltable(entries: entries / 16);
801 pr_info("Started %d threads, %d failed, rhltable test returns %d\n",
802 started_threads, failed_threads, err);
803 return 0;
804}
805
806static void __exit test_rht_exit(void)
807{
808}
809
810module_init(test_rht_init);
811module_exit(test_rht_exit);
812
813MODULE_LICENSE("GPL v2");
814

source code of linux/lib/test_rhashtable.c