xref: /openbmc/linux/lib/test_rhashtable.c (revision 9a29ad52)
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/random.h>
27 #include <linux/vmalloc.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) << RHT_HASH_RESERVED_SPACE;
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 	.nulls_base = (3U << RHT_BASE_SHIFT),
103 };
104 
105 static struct rhashtable_params test_rht_params_dup = {
106 	.head_offset = offsetof(struct test_obj_rhl, list_node),
107 	.key_offset = offsetof(struct test_obj_rhl, value),
108 	.key_len = sizeof(struct test_obj_val),
109 	.hashfn = jhash,
110 	.obj_hashfn = my_hashfn,
111 	.obj_cmpfn = my_cmpfn,
112 	.nelem_hint = 128,
113 	.automatic_shrinking = false,
114 };
115 
116 static struct semaphore prestart_sem;
117 static struct semaphore startup_sem = __SEMAPHORE_INITIALIZER(startup_sem, 0);
118 
119 static int insert_retry(struct rhashtable *ht, struct test_obj *obj,
120                         const struct rhashtable_params params)
121 {
122 	int err, retries = -1, enomem_retries = 0;
123 
124 	do {
125 		retries++;
126 		cond_resched();
127 		err = rhashtable_insert_fast(ht, &obj->node, params);
128 		if (err == -ENOMEM && enomem_retry) {
129 			enomem_retries++;
130 			err = -EBUSY;
131 		}
132 	} while (err == -EBUSY);
133 
134 	if (enomem_retries)
135 		pr_info(" %u insertions retried after -ENOMEM\n",
136 			enomem_retries);
137 
138 	return err ? : retries;
139 }
140 
141 static int __init test_rht_lookup(struct rhashtable *ht, struct test_obj *array,
142 				  unsigned int entries)
143 {
144 	unsigned int i;
145 
146 	for (i = 0; i < entries; i++) {
147 		struct test_obj *obj;
148 		bool expected = !(i % 2);
149 		struct test_obj_val key = {
150 			.id = i,
151 		};
152 
153 		if (array[i / 2].value.id == TEST_INSERT_FAIL)
154 			expected = false;
155 
156 		obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
157 
158 		if (expected && !obj) {
159 			pr_warn("Test failed: Could not find key %u\n", key.id);
160 			return -ENOENT;
161 		} else if (!expected && obj) {
162 			pr_warn("Test failed: Unexpected entry found for key %u\n",
163 				key.id);
164 			return -EEXIST;
165 		} else if (expected && obj) {
166 			if (obj->value.id != i) {
167 				pr_warn("Test failed: Lookup value mismatch %u!=%u\n",
168 					obj->value.id, i);
169 				return -EINVAL;
170 			}
171 		}
172 
173 		cond_resched_rcu();
174 	}
175 
176 	return 0;
177 }
178 
179 static void test_bucket_stats(struct rhashtable *ht, unsigned int entries)
180 {
181 	unsigned int err, total = 0, chain_len = 0;
182 	struct rhashtable_iter hti;
183 	struct rhash_head *pos;
184 
185 	err = rhashtable_walk_init(ht, &hti, GFP_KERNEL);
186 	if (err) {
187 		pr_warn("Test failed: allocation error");
188 		return;
189 	}
190 
191 	rhashtable_walk_start(&hti);
192 
193 	while ((pos = rhashtable_walk_next(&hti))) {
194 		if (PTR_ERR(pos) == -EAGAIN) {
195 			pr_info("Info: encountered resize\n");
196 			chain_len++;
197 			continue;
198 		} else if (IS_ERR(pos)) {
199 			pr_warn("Test failed: rhashtable_walk_next() error: %ld\n",
200 				PTR_ERR(pos));
201 			break;
202 		}
203 
204 		total++;
205 	}
206 
207 	rhashtable_walk_stop(&hti);
208 	rhashtable_walk_exit(&hti);
209 
210 	pr_info("  Traversal complete: counted=%u, nelems=%u, entries=%d, table-jumps=%u\n",
211 		total, atomic_read(&ht->nelems), entries, chain_len);
212 
213 	if (total != atomic_read(&ht->nelems) || total != entries)
214 		pr_warn("Test failed: Total count mismatch ^^^");
215 }
216 
217 static s64 __init test_rhashtable(struct rhashtable *ht, struct test_obj *array,
218 				  unsigned int entries)
219 {
220 	struct test_obj *obj;
221 	int err;
222 	unsigned int i, insert_retries = 0;
223 	s64 start, end;
224 
225 	/*
226 	 * Insertion Test:
227 	 * Insert entries into table with all keys even numbers
228 	 */
229 	pr_info("  Adding %d keys\n", entries);
230 	start = ktime_get_ns();
231 	for (i = 0; i < entries; i++) {
232 		struct test_obj *obj = &array[i];
233 
234 		obj->value.id = i * 2;
235 		err = insert_retry(ht, obj, test_rht_params);
236 		if (err > 0)
237 			insert_retries += err;
238 		else if (err)
239 			return err;
240 	}
241 
242 	if (insert_retries)
243 		pr_info("  %u insertions retried due to memory pressure\n",
244 			insert_retries);
245 
246 	test_bucket_stats(ht, entries);
247 	rcu_read_lock();
248 	test_rht_lookup(ht, array, entries);
249 	rcu_read_unlock();
250 
251 	test_bucket_stats(ht, entries);
252 
253 	pr_info("  Deleting %d keys\n", entries);
254 	for (i = 0; i < entries; i++) {
255 		struct test_obj_val key = {
256 			.id = i * 2,
257 		};
258 
259 		if (array[i].value.id != TEST_INSERT_FAIL) {
260 			obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
261 			BUG_ON(!obj);
262 
263 			rhashtable_remove_fast(ht, &obj->node, test_rht_params);
264 		}
265 
266 		cond_resched();
267 	}
268 
269 	end = ktime_get_ns();
270 	pr_info("  Duration of test: %lld ns\n", end - start);
271 
272 	return end - start;
273 }
274 
275 static struct rhashtable ht;
276 static struct rhltable rhlt;
277 
278 static int __init test_rhltable(unsigned int entries)
279 {
280 	struct test_obj_rhl *rhl_test_objects;
281 	unsigned long *obj_in_table;
282 	unsigned int i, j, k;
283 	int ret, err;
284 
285 	if (entries == 0)
286 		entries = 1;
287 
288 	rhl_test_objects = vzalloc(array_size(entries,
289 					      sizeof(*rhl_test_objects)));
290 	if (!rhl_test_objects)
291 		return -ENOMEM;
292 
293 	ret = -ENOMEM;
294 	obj_in_table = vzalloc(array_size(sizeof(unsigned long),
295 					  BITS_TO_LONGS(entries)));
296 	if (!obj_in_table)
297 		goto out_free;
298 
299 	/* nulls_base not supported in rhlist interface */
300 	test_rht_params.nulls_base = 0;
301 	err = rhltable_init(&rhlt, &test_rht_params);
302 	if (WARN_ON(err))
303 		goto out_free;
304 
305 	k = prandom_u32();
306 	ret = 0;
307 	for (i = 0; i < entries; i++) {
308 		rhl_test_objects[i].value.id = k;
309 		err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node,
310 				      test_rht_params);
311 		if (WARN(err, "error %d on element %d\n", err, i))
312 			break;
313 		if (err == 0)
314 			set_bit(i, obj_in_table);
315 	}
316 
317 	if (err)
318 		ret = err;
319 
320 	pr_info("test %d add/delete pairs into rhlist\n", entries);
321 	for (i = 0; i < entries; i++) {
322 		struct rhlist_head *h, *pos;
323 		struct test_obj_rhl *obj;
324 		struct test_obj_val key = {
325 			.id = k,
326 		};
327 		bool found;
328 
329 		rcu_read_lock();
330 		h = rhltable_lookup(&rhlt, &key, test_rht_params);
331 		if (WARN(!h, "key not found during iteration %d of %d", i, entries)) {
332 			rcu_read_unlock();
333 			break;
334 		}
335 
336 		if (i) {
337 			j = i - 1;
338 			rhl_for_each_entry_rcu(obj, pos, h, list_node) {
339 				if (WARN(pos == &rhl_test_objects[j].list_node, "old element found, should be gone"))
340 					break;
341 			}
342 		}
343 
344 		cond_resched_rcu();
345 
346 		found = false;
347 
348 		rhl_for_each_entry_rcu(obj, pos, h, list_node) {
349 			if (pos == &rhl_test_objects[i].list_node) {
350 				found = true;
351 				break;
352 			}
353 		}
354 
355 		rcu_read_unlock();
356 
357 		if (WARN(!found, "element %d not found", i))
358 			break;
359 
360 		err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
361 		WARN(err, "rhltable_remove: err %d for iteration %d\n", err, i);
362 		if (err == 0)
363 			clear_bit(i, obj_in_table);
364 	}
365 
366 	if (ret == 0 && err)
367 		ret = err;
368 
369 	for (i = 0; i < entries; i++) {
370 		WARN(test_bit(i, obj_in_table), "elem %d allegedly still present", i);
371 
372 		err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node,
373 				      test_rht_params);
374 		if (WARN(err, "error %d on element %d\n", err, i))
375 			break;
376 		if (err == 0)
377 			set_bit(i, obj_in_table);
378 	}
379 
380 	pr_info("test %d random rhlist add/delete operations\n", entries);
381 	for (j = 0; j < entries; j++) {
382 		u32 i = prandom_u32_max(entries);
383 		u32 prand = prandom_u32();
384 
385 		cond_resched();
386 
387 		if (prand == 0)
388 			prand = prandom_u32();
389 
390 		if (prand & 1) {
391 			prand >>= 1;
392 			continue;
393 		}
394 
395 		err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
396 		if (test_bit(i, obj_in_table)) {
397 			clear_bit(i, obj_in_table);
398 			if (WARN(err, "cannot remove element at slot %d", i))
399 				continue;
400 		} else {
401 			if (WARN(err != -ENOENT, "removed non-existant element %d, error %d not %d",
402 			     i, err, -ENOENT))
403 				continue;
404 		}
405 
406 		if (prand & 1) {
407 			prand >>= 1;
408 			continue;
409 		}
410 
411 		err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
412 		if (err == 0) {
413 			if (WARN(test_and_set_bit(i, obj_in_table), "succeeded to insert same object %d", i))
414 				continue;
415 		} else {
416 			if (WARN(!test_bit(i, obj_in_table), "failed to insert object %d", i))
417 				continue;
418 		}
419 
420 		if (prand & 1) {
421 			prand >>= 1;
422 			continue;
423 		}
424 
425 		i = prandom_u32_max(entries);
426 		if (test_bit(i, obj_in_table)) {
427 			err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
428 			WARN(err, "cannot remove element at slot %d", i);
429 			if (err == 0)
430 				clear_bit(i, obj_in_table);
431 		} else {
432 			err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
433 			WARN(err, "failed to insert object %d", i);
434 			if (err == 0)
435 				set_bit(i, obj_in_table);
436 		}
437 	}
438 
439 	for (i = 0; i < entries; i++) {
440 		cond_resched();
441 		err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
442 		if (test_bit(i, obj_in_table)) {
443 			if (WARN(err, "cannot remove element at slot %d", i))
444 				continue;
445 		} else {
446 			if (WARN(err != -ENOENT, "removed non-existant element, error %d not %d",
447 				 err, -ENOENT))
448 			continue;
449 		}
450 	}
451 
452 	rhltable_destroy(&rhlt);
453 out_free:
454 	vfree(rhl_test_objects);
455 	vfree(obj_in_table);
456 	return ret;
457 }
458 
459 static int __init test_rhashtable_max(struct test_obj *array,
460 				      unsigned int entries)
461 {
462 	unsigned int i, insert_retries = 0;
463 	int err;
464 
465 	test_rht_params.max_size = roundup_pow_of_two(entries / 8);
466 	err = rhashtable_init(&ht, &test_rht_params);
467 	if (err)
468 		return err;
469 
470 	for (i = 0; i < ht.max_elems; i++) {
471 		struct test_obj *obj = &array[i];
472 
473 		obj->value.id = i * 2;
474 		err = insert_retry(&ht, obj, test_rht_params);
475 		if (err > 0)
476 			insert_retries += err;
477 		else if (err)
478 			return err;
479 	}
480 
481 	err = insert_retry(&ht, &array[ht.max_elems], test_rht_params);
482 	if (err == -E2BIG) {
483 		err = 0;
484 	} else {
485 		pr_info("insert element %u should have failed with %d, got %d\n",
486 				ht.max_elems, -E2BIG, err);
487 		if (err == 0)
488 			err = -1;
489 	}
490 
491 	rhashtable_destroy(&ht);
492 
493 	return err;
494 }
495 
496 static unsigned int __init print_ht(struct rhltable *rhlt)
497 {
498 	struct rhashtable *ht;
499 	const struct bucket_table *tbl;
500 	char buff[512] = "";
501 	unsigned int i, cnt = 0;
502 
503 	ht = &rhlt->ht;
504 	tbl = rht_dereference(ht->tbl, ht);
505 	for (i = 0; i < tbl->size; i++) {
506 		struct rhash_head *pos, *next;
507 		struct test_obj_rhl *p;
508 
509 		pos = rht_dereference(tbl->buckets[i], ht);
510 		next = !rht_is_a_nulls(pos) ? rht_dereference(pos->next, ht) : NULL;
511 
512 		if (!rht_is_a_nulls(pos)) {
513 			sprintf(buff, "%s\nbucket[%d] -> ", buff, i);
514 		}
515 
516 		while (!rht_is_a_nulls(pos)) {
517 			struct rhlist_head *list = container_of(pos, struct rhlist_head, rhead);
518 			sprintf(buff, "%s[[", buff);
519 			do {
520 				pos = &list->rhead;
521 				list = rht_dereference(list->next, ht);
522 				p = rht_obj(ht, pos);
523 
524 				sprintf(buff, "%s val %d (tid=%d)%s", buff, p->value.id, p->value.tid,
525 					list? ", " : " ");
526 				cnt++;
527 			} while (list);
528 
529 			pos = next,
530 			next = !rht_is_a_nulls(pos) ?
531 				rht_dereference(pos->next, ht) : NULL;
532 
533 			sprintf(buff, "%s]]%s", buff, !rht_is_a_nulls(pos) ? " -> " : "");
534 		}
535 	}
536 	printk(KERN_ERR "\n---- ht: ----%s\n-------------\n", buff);
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 	err = rhltable_init(&rhlt, &test_rht_params_dup);
550 	if (WARN_ON(err))
551 		return err;
552 
553 	for (i = 0; i < cnt; i++) {
554 		rhl_test_objects[i].value.tid = i;
555 		key = rht_obj(&rhlt.ht, &rhl_test_objects[i].list_node.rhead);
556 		key += test_rht_params_dup.key_offset;
557 
558 		if (slow) {
559 			err = PTR_ERR(rhashtable_insert_slow(&rhlt.ht, key,
560 							     &rhl_test_objects[i].list_node.rhead));
561 			if (err == -EAGAIN)
562 				err = 0;
563 		} else
564 			err = rhltable_insert(&rhlt,
565 					      &rhl_test_objects[i].list_node,
566 					      test_rht_params_dup);
567 		if (WARN(err, "error %d on element %d/%d (%s)\n", err, i, cnt, slow? "slow" : "fast"))
568 			goto skip_print;
569 	}
570 
571 	ret = print_ht(&rhlt);
572 	WARN(ret != cnt, "missing rhltable elements (%d != %d, %s)\n", ret, cnt, slow? "slow" : "fast");
573 
574 skip_print:
575 	rhltable_destroy(&rhlt);
576 
577 	return 0;
578 }
579 
580 static int __init test_insert_duplicates_run(void)
581 {
582 	struct test_obj_rhl rhl_test_objects[3] = {};
583 
584 	pr_info("test inserting duplicates\n");
585 
586 	/* two different values that map to same bucket */
587 	rhl_test_objects[0].value.id = 1;
588 	rhl_test_objects[1].value.id = 21;
589 
590 	/* and another duplicate with same as [0] value
591 	 * which will be second on the bucket list */
592 	rhl_test_objects[2].value.id = rhl_test_objects[0].value.id;
593 
594 	test_insert_dup(rhl_test_objects, 2, false);
595 	test_insert_dup(rhl_test_objects, 3, false);
596 	test_insert_dup(rhl_test_objects, 2, true);
597 	test_insert_dup(rhl_test_objects, 3, true);
598 
599 	return 0;
600 }
601 
602 static int thread_lookup_test(struct thread_data *tdata)
603 {
604 	unsigned int entries = tdata->entries;
605 	int i, err = 0;
606 
607 	for (i = 0; i < entries; i++) {
608 		struct test_obj *obj;
609 		struct test_obj_val key = {
610 			.id = i,
611 			.tid = tdata->id,
612 		};
613 
614 		obj = rhashtable_lookup_fast(&ht, &key, test_rht_params);
615 		if (obj && (tdata->objs[i].value.id == TEST_INSERT_FAIL)) {
616 			pr_err("  found unexpected object %d-%d\n", key.tid, key.id);
617 			err++;
618 		} else if (!obj && (tdata->objs[i].value.id != TEST_INSERT_FAIL)) {
619 			pr_err("  object %d-%d not found!\n", key.tid, key.id);
620 			err++;
621 		} else if (obj && memcmp(&obj->value, &key, sizeof(key))) {
622 			pr_err("  wrong object returned (got %d-%d, expected %d-%d)\n",
623 			       obj->value.tid, obj->value.id, key.tid, key.id);
624 			err++;
625 		}
626 
627 		cond_resched();
628 	}
629 	return err;
630 }
631 
632 static int threadfunc(void *data)
633 {
634 	int i, step, err = 0, insert_retries = 0;
635 	struct thread_data *tdata = data;
636 
637 	up(&prestart_sem);
638 	if (down_interruptible(&startup_sem))
639 		pr_err("  thread[%d]: down_interruptible failed\n", tdata->id);
640 
641 	for (i = 0; i < tdata->entries; i++) {
642 		tdata->objs[i].value.id = i;
643 		tdata->objs[i].value.tid = tdata->id;
644 		err = insert_retry(&ht, &tdata->objs[i], test_rht_params);
645 		if (err > 0) {
646 			insert_retries += err;
647 		} else if (err) {
648 			pr_err("  thread[%d]: rhashtable_insert_fast failed\n",
649 			       tdata->id);
650 			goto out;
651 		}
652 	}
653 	if (insert_retries)
654 		pr_info("  thread[%d]: %u insertions retried due to memory pressure\n",
655 			tdata->id, insert_retries);
656 
657 	err = thread_lookup_test(tdata);
658 	if (err) {
659 		pr_err("  thread[%d]: rhashtable_lookup_test failed\n",
660 		       tdata->id);
661 		goto out;
662 	}
663 
664 	for (step = 10; step > 0; step--) {
665 		for (i = 0; i < tdata->entries; i += step) {
666 			if (tdata->objs[i].value.id == TEST_INSERT_FAIL)
667 				continue;
668 			err = rhashtable_remove_fast(&ht, &tdata->objs[i].node,
669 			                             test_rht_params);
670 			if (err) {
671 				pr_err("  thread[%d]: rhashtable_remove_fast failed\n",
672 				       tdata->id);
673 				goto out;
674 			}
675 			tdata->objs[i].value.id = TEST_INSERT_FAIL;
676 
677 			cond_resched();
678 		}
679 		err = thread_lookup_test(tdata);
680 		if (err) {
681 			pr_err("  thread[%d]: rhashtable_lookup_test (2) failed\n",
682 			       tdata->id);
683 			goto out;
684 		}
685 	}
686 out:
687 	while (!kthread_should_stop()) {
688 		set_current_state(TASK_INTERRUPTIBLE);
689 		schedule();
690 	}
691 	return err;
692 }
693 
694 static int __init test_rht_init(void)
695 {
696 	unsigned int entries;
697 	int i, err, started_threads = 0, failed_threads = 0;
698 	u64 total_time = 0;
699 	struct thread_data *tdata;
700 	struct test_obj *objs;
701 
702 	if (parm_entries < 0)
703 		parm_entries = 1;
704 
705 	entries = min(parm_entries, MAX_ENTRIES);
706 
707 	test_rht_params.automatic_shrinking = shrinking;
708 	test_rht_params.max_size = max_size ? : roundup_pow_of_two(entries);
709 	test_rht_params.nelem_hint = size;
710 
711 	objs = vzalloc(array_size(sizeof(struct test_obj),
712 				  test_rht_params.max_size + 1));
713 	if (!objs)
714 		return -ENOMEM;
715 
716 	pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n",
717 		size, max_size, shrinking);
718 
719 	for (i = 0; i < runs; i++) {
720 		s64 time;
721 
722 		pr_info("Test %02d:\n", i);
723 		memset(objs, 0, test_rht_params.max_size * sizeof(struct test_obj));
724 
725 		err = rhashtable_init(&ht, &test_rht_params);
726 		if (err < 0) {
727 			pr_warn("Test failed: Unable to initialize hashtable: %d\n",
728 				err);
729 			continue;
730 		}
731 
732 		time = test_rhashtable(&ht, objs, entries);
733 		rhashtable_destroy(&ht);
734 		if (time < 0) {
735 			vfree(objs);
736 			pr_warn("Test failed: return code %lld\n", time);
737 			return -EINVAL;
738 		}
739 
740 		total_time += time;
741 	}
742 
743 	pr_info("test if its possible to exceed max_size %d: %s\n",
744 			test_rht_params.max_size, test_rhashtable_max(objs, entries) == 0 ?
745 			"no, ok" : "YES, failed");
746 	vfree(objs);
747 
748 	do_div(total_time, runs);
749 	pr_info("Average test time: %llu\n", total_time);
750 
751 	test_insert_duplicates_run();
752 
753 	if (!tcount)
754 		return 0;
755 
756 	pr_info("Testing concurrent rhashtable access from %d threads\n",
757 	        tcount);
758 	sema_init(&prestart_sem, 1 - tcount);
759 	tdata = vzalloc(array_size(tcount, sizeof(struct thread_data)));
760 	if (!tdata)
761 		return -ENOMEM;
762 	objs  = vzalloc(array3_size(sizeof(struct test_obj), tcount, entries));
763 	if (!objs) {
764 		vfree(tdata);
765 		return -ENOMEM;
766 	}
767 
768 	test_rht_params.max_size = max_size ? :
769 	                           roundup_pow_of_two(tcount * entries);
770 	err = rhashtable_init(&ht, &test_rht_params);
771 	if (err < 0) {
772 		pr_warn("Test failed: Unable to initialize hashtable: %d\n",
773 			err);
774 		vfree(tdata);
775 		vfree(objs);
776 		return -EINVAL;
777 	}
778 	for (i = 0; i < tcount; i++) {
779 		tdata[i].id = i;
780 		tdata[i].entries = entries;
781 		tdata[i].objs = objs + i * entries;
782 		tdata[i].task = kthread_run(threadfunc, &tdata[i],
783 		                            "rhashtable_thrad[%d]", i);
784 		if (IS_ERR(tdata[i].task))
785 			pr_err(" kthread_run failed for thread %d\n", i);
786 		else
787 			started_threads++;
788 	}
789 	if (down_interruptible(&prestart_sem))
790 		pr_err("  down interruptible failed\n");
791 	for (i = 0; i < tcount; i++)
792 		up(&startup_sem);
793 	for (i = 0; i < tcount; i++) {
794 		if (IS_ERR(tdata[i].task))
795 			continue;
796 		if ((err = kthread_stop(tdata[i].task))) {
797 			pr_warn("Test failed: thread %d returned: %d\n",
798 			        i, err);
799 			failed_threads++;
800 		}
801 	}
802 	rhashtable_destroy(&ht);
803 	vfree(tdata);
804 	vfree(objs);
805 
806 	/*
807 	 * rhltable_remove is very expensive, default values can cause test
808 	 * to run for 2 minutes or more,  use a smaller number instead.
809 	 */
810 	err = test_rhltable(entries / 16);
811 	pr_info("Started %d threads, %d failed, rhltable test returns %d\n",
812 	        started_threads, failed_threads, err);
813 	return 0;
814 }
815 
816 static void __exit test_rht_exit(void)
817 {
818 }
819 
820 module_init(test_rht_init);
821 module_exit(test_rht_exit);
822 
823 MODULE_LICENSE("GPL v2");
824