xref: /linux/lib/test_rhashtable.c (revision 9190d4a263264eabf715f5fc1827da45e3fdc247)
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 
29 static int parm_entries = 50000;
30 module_param(parm_entries, int, 0);
31 MODULE_PARM_DESC(parm_entries, "Number of entries to add (default: 50000)");
32 
33 static int runs = 4;
34 module_param(runs, int, 0);
35 MODULE_PARM_DESC(runs, "Number of test runs per variant (default: 4)");
36 
37 static int max_size = 0;
38 module_param(max_size, int, 0);
39 MODULE_PARM_DESC(max_size, "Maximum table size (default: calculated)");
40 
41 static bool shrinking = false;
42 module_param(shrinking, bool, 0);
43 MODULE_PARM_DESC(shrinking, "Enable automatic shrinking (default: off)");
44 
45 static int size = 8;
46 module_param(size, int, 0);
47 MODULE_PARM_DESC(size, "Initial size hint of table (default: 8)");
48 
49 static int tcount = 10;
50 module_param(tcount, int, 0);
51 MODULE_PARM_DESC(tcount, "Number of threads to spawn (default: 10)");
52 
53 static bool enomem_retry = false;
54 module_param(enomem_retry, bool, 0);
55 MODULE_PARM_DESC(enomem_retry, "Retry insert even if -ENOMEM was returned (default: off)");
56 
57 struct test_obj_val {
58 	int	id;
59 	int	tid;
60 };
61 
62 struct test_obj {
63 	struct test_obj_val	value;
64 	struct rhash_head	node;
65 };
66 
67 struct test_obj_rhl {
68 	struct test_obj_val	value;
69 	struct rhlist_head	list_node;
70 };
71 
72 struct thread_data {
73 	unsigned int entries;
74 	int id;
75 	struct task_struct *task;
76 	struct test_obj *objs;
77 };
78 
79 static 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 
86 static 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 
94 static 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 
101 static 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 
112 static atomic_t startup_count;
113 static DECLARE_WAIT_QUEUE_HEAD(startup_wait);
114 
115 static 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->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 
137 static 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, 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 
175 static 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, &hti);
182 	rhashtable_walk_start(&hti);
183 
184 	while ((pos = rhashtable_walk_next(&hti))) {
185 		if (PTR_ERR(pos) == -EAGAIN) {
186 			pr_info("Info: encountered resize\n");
187 			chain_len++;
188 			continue;
189 		} else if (IS_ERR(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(&hti);
199 	rhashtable_walk_exit(&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(&ht->nelems) || total != entries)
205 		pr_warn("Test failed: Total count mismatch ^^^");
206 }
207 
208 static 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, 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, test_rht_params);
252 			BUG_ON(!obj);
253 
254 			rhashtable_remove_fast(ht, &obj->node, 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 
266 static struct rhashtable ht;
267 static struct rhltable rhlt;
268 
269 static 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(&rhlt, &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(&rhlt, &rhl_test_objects[i].list_node,
299 				      test_rht_params);
300 		if (WARN(err, "error %d on element %d\n", err, i))
301 			break;
302 		if (err == 0)
303 			set_bit(i, 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(&rhlt, &key, 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(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
350 		WARN(err, "rhltable_remove: err %d for iteration %d\n", err, i);
351 		if (err == 0)
352 			clear_bit(i, 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(&rhlt, &rhl_test_objects[i].list_node,
362 				      test_rht_params);
363 		if (WARN(err, "error %d on element %d\n", err, i))
364 			break;
365 		if (err == 0)
366 			set_bit(i, 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 = prandom_u32_max(entries);
372 		u32 prand = prandom_u32_max(4);
373 
374 		cond_resched();
375 
376 		err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
377 		if (test_bit(i, obj_in_table)) {
378 			clear_bit(i, 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(&rhlt, &rhl_test_objects[i].list_node, 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 = prandom_u32_max(entries);
400 			if (test_bit(i, obj_in_table)) {
401 				err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
402 				WARN(err, "cannot remove element at slot %d", i);
403 				if (err == 0)
404 					clear_bit(i, obj_in_table);
405 			} else {
406 				err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
407 				WARN(err, "failed to insert object %d", i);
408 				if (err == 0)
409 					set_bit(i, obj_in_table);
410 			}
411 		}
412 	}
413 
414 	for (i = 0; i < entries; i++) {
415 		cond_resched();
416 		err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, 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(&rhlt);
428 out_free:
429 	vfree(rhl_test_objects);
430 	vfree(obj_in_table);
431 	return ret;
432 }
433 
434 static int __init test_rhashtable_max(struct test_obj *array,
435 				      unsigned int entries)
436 {
437 	unsigned int i, insert_retries = 0;
438 	int err;
439 
440 	test_rht_params.max_size = roundup_pow_of_two(entries / 8);
441 	err = rhashtable_init(&ht, &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, obj, test_rht_params);
450 		if (err > 0)
451 			insert_retries += err;
452 		else if (err)
453 			return err;
454 	}
455 
456 	err = insert_retry(&ht, &array[ht.max_elems], test_rht_params);
457 	if (err == -E2BIG) {
458 		err = 0;
459 	} else {
460 		pr_info("insert element %u should have failed with %d, got %d\n",
461 				ht.max_elems, -E2BIG, err);
462 		if (err == 0)
463 			err = -1;
464 	}
465 
466 	rhashtable_destroy(&ht);
467 
468 	return err;
469 }
470 
471 static unsigned int __init print_ht(struct rhltable *rhlt)
472 {
473 	struct rhashtable *ht;
474 	const struct bucket_table *tbl;
475 	char buff[512] = "";
476 	int offset = 0;
477 	unsigned int i, cnt = 0;
478 
479 	ht = &rhlt->ht;
480 	/* Take the mutex to avoid RCU warning */
481 	mutex_lock(&ht->mutex);
482 	tbl = rht_dereference(ht->tbl, ht);
483 	for (i = 0; i < tbl->size; i++) {
484 		struct rhash_head *pos, *next;
485 		struct test_obj_rhl *p;
486 
487 		pos = rht_ptr_exclusive(tbl->buckets + i);
488 		next = !rht_is_a_nulls(pos) ? rht_dereference(pos->next, ht) : NULL;
489 
490 		if (!rht_is_a_nulls(pos)) {
491 			offset += sprintf(buff + offset, "\nbucket[%d] -> ", i);
492 		}
493 
494 		while (!rht_is_a_nulls(pos)) {
495 			struct rhlist_head *list = container_of(pos, struct rhlist_head, rhead);
496 			offset += sprintf(buff + offset, "[[");
497 			do {
498 				pos = &list->rhead;
499 				list = rht_dereference(list->next, ht);
500 				p = rht_obj(ht, pos);
501 
502 				offset += sprintf(buff + offset, " val %d (tid=%d)%s", p->value.id, p->value.tid,
503 					list? ", " : " ");
504 				cnt++;
505 			} while (list);
506 
507 			pos = next,
508 			next = !rht_is_a_nulls(pos) ?
509 				rht_dereference(pos->next, ht) : NULL;
510 
511 			offset += sprintf(buff + offset, "]]%s", !rht_is_a_nulls(pos) ? " -> " : "");
512 		}
513 	}
514 	printk(KERN_ERR "\n---- ht: ----%s\n-------------\n", buff);
515 	mutex_unlock(&ht->mutex);
516 
517 	return cnt;
518 }
519 
520 static int __init test_insert_dup(struct test_obj_rhl *rhl_test_objects,
521 				  int cnt, bool slow)
522 {
523 	struct rhltable *rhlt;
524 	unsigned int i, ret;
525 	const char *key;
526 	int err = 0;
527 
528 	rhlt = kmalloc(sizeof(*rhlt), GFP_KERNEL);
529 	if (WARN_ON(!rhlt))
530 		return -EINVAL;
531 
532 	err = rhltable_init(rhlt, &test_rht_params_dup);
533 	if (WARN_ON(err)) {
534 		kfree(rhlt);
535 		return err;
536 	}
537 
538 	for (i = 0; i < cnt; i++) {
539 		rhl_test_objects[i].value.tid = i;
540 		key = rht_obj(&rhlt->ht, &rhl_test_objects[i].list_node.rhead);
541 		key += test_rht_params_dup.key_offset;
542 
543 		if (slow) {
544 			err = PTR_ERR(rhashtable_insert_slow(&rhlt->ht, key,
545 							     &rhl_test_objects[i].list_node.rhead));
546 			if (err == -EAGAIN)
547 				err = 0;
548 		} else
549 			err = rhltable_insert(rhlt,
550 					      &rhl_test_objects[i].list_node,
551 					      test_rht_params_dup);
552 		if (WARN(err, "error %d on element %d/%d (%s)\n", err, i, cnt, slow? "slow" : "fast"))
553 			goto skip_print;
554 	}
555 
556 	ret = print_ht(rhlt);
557 	WARN(ret != cnt, "missing rhltable elements (%d != %d, %s)\n", ret, cnt, slow? "slow" : "fast");
558 
559 skip_print:
560 	rhltable_destroy(rhlt);
561 	kfree(rhlt);
562 
563 	return 0;
564 }
565 
566 static int __init test_insert_duplicates_run(void)
567 {
568 	struct test_obj_rhl rhl_test_objects[3] = {};
569 
570 	pr_info("test inserting duplicates\n");
571 
572 	/* two different values that map to same bucket */
573 	rhl_test_objects[0].value.id = 1;
574 	rhl_test_objects[1].value.id = 21;
575 
576 	/* and another duplicate with same as [0] value
577 	 * which will be second on the bucket list */
578 	rhl_test_objects[2].value.id = rhl_test_objects[0].value.id;
579 
580 	test_insert_dup(rhl_test_objects, 2, false);
581 	test_insert_dup(rhl_test_objects, 3, false);
582 	test_insert_dup(rhl_test_objects, 2, true);
583 	test_insert_dup(rhl_test_objects, 3, true);
584 
585 	return 0;
586 }
587 
588 static int thread_lookup_test(struct thread_data *tdata)
589 {
590 	unsigned int entries = tdata->entries;
591 	int i, err = 0;
592 
593 	for (i = 0; i < entries; i++) {
594 		struct test_obj *obj;
595 		struct test_obj_val key = {
596 			.id = i,
597 			.tid = tdata->id,
598 		};
599 
600 		obj = rhashtable_lookup_fast(&ht, &key, test_rht_params);
601 		if (obj && (tdata->objs[i].value.id == TEST_INSERT_FAIL)) {
602 			pr_err("  found unexpected object %d-%d\n", key.tid, key.id);
603 			err++;
604 		} else if (!obj && (tdata->objs[i].value.id != TEST_INSERT_FAIL)) {
605 			pr_err("  object %d-%d not found!\n", key.tid, key.id);
606 			err++;
607 		} else if (obj && memcmp(&obj->value, &key, sizeof(key))) {
608 			pr_err("  wrong object returned (got %d-%d, expected %d-%d)\n",
609 			       obj->value.tid, obj->value.id, key.tid, key.id);
610 			err++;
611 		}
612 
613 		cond_resched();
614 	}
615 	return err;
616 }
617 
618 static int threadfunc(void *data)
619 {
620 	int i, step, err = 0, insert_retries = 0;
621 	struct thread_data *tdata = data;
622 
623 	if (atomic_dec_and_test(&startup_count))
624 		wake_up(&startup_wait);
625 	if (wait_event_interruptible(startup_wait, atomic_read(&startup_count) == -1)) {
626 		pr_err("  thread[%d]: interrupted\n", tdata->id);
627 		goto out;
628 	}
629 
630 	for (i = 0; i < tdata->entries; i++) {
631 		tdata->objs[i].value.id = i;
632 		tdata->objs[i].value.tid = tdata->id;
633 		err = insert_retry(&ht, &tdata->objs[i], test_rht_params);
634 		if (err > 0) {
635 			insert_retries += err;
636 		} else if (err) {
637 			pr_err("  thread[%d]: rhashtable_insert_fast failed\n",
638 			       tdata->id);
639 			goto out;
640 		}
641 	}
642 	if (insert_retries)
643 		pr_info("  thread[%d]: %u insertions retried due to memory pressure\n",
644 			tdata->id, insert_retries);
645 
646 	err = thread_lookup_test(tdata);
647 	if (err) {
648 		pr_err("  thread[%d]: rhashtable_lookup_test failed\n",
649 		       tdata->id);
650 		goto out;
651 	}
652 
653 	for (step = 10; step > 0; step--) {
654 		for (i = 0; i < tdata->entries; i += step) {
655 			if (tdata->objs[i].value.id == TEST_INSERT_FAIL)
656 				continue;
657 			err = rhashtable_remove_fast(&ht, &tdata->objs[i].node,
658 			                             test_rht_params);
659 			if (err) {
660 				pr_err("  thread[%d]: rhashtable_remove_fast failed\n",
661 				       tdata->id);
662 				goto out;
663 			}
664 			tdata->objs[i].value.id = TEST_INSERT_FAIL;
665 
666 			cond_resched();
667 		}
668 		err = thread_lookup_test(tdata);
669 		if (err) {
670 			pr_err("  thread[%d]: rhashtable_lookup_test (2) failed\n",
671 			       tdata->id);
672 			goto out;
673 		}
674 	}
675 out:
676 	while (!kthread_should_stop()) {
677 		set_current_state(TASK_INTERRUPTIBLE);
678 		schedule();
679 	}
680 	return err;
681 }
682 
683 static int __init test_rht_init(void)
684 {
685 	unsigned int entries;
686 	int i, err, started_threads = 0, failed_threads = 0;
687 	u64 total_time = 0;
688 	struct thread_data *tdata;
689 	struct test_obj *objs;
690 
691 	if (parm_entries < 0)
692 		parm_entries = 1;
693 
694 	entries = min(parm_entries, MAX_ENTRIES);
695 
696 	test_rht_params.automatic_shrinking = shrinking;
697 	test_rht_params.max_size = max_size ? : roundup_pow_of_two(entries);
698 	test_rht_params.nelem_hint = size;
699 
700 	objs = vzalloc(array_size(sizeof(struct test_obj),
701 				  test_rht_params.max_size + 1));
702 	if (!objs)
703 		return -ENOMEM;
704 
705 	pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n",
706 		size, max_size, shrinking);
707 
708 	for (i = 0; i < runs; i++) {
709 		s64 time;
710 
711 		pr_info("Test %02d:\n", i);
712 		memset(objs, 0, test_rht_params.max_size * sizeof(struct test_obj));
713 
714 		err = rhashtable_init(&ht, &test_rht_params);
715 		if (err < 0) {
716 			pr_warn("Test failed: Unable to initialize hashtable: %d\n",
717 				err);
718 			continue;
719 		}
720 
721 		time = test_rhashtable(&ht, objs, entries);
722 		rhashtable_destroy(&ht);
723 		if (time < 0) {
724 			vfree(objs);
725 			pr_warn("Test failed: return code %lld\n", time);
726 			return -EINVAL;
727 		}
728 
729 		total_time += time;
730 	}
731 
732 	pr_info("test if its possible to exceed max_size %d: %s\n",
733 			test_rht_params.max_size, test_rhashtable_max(objs, entries) == 0 ?
734 			"no, ok" : "YES, failed");
735 	vfree(objs);
736 
737 	do_div(total_time, runs);
738 	pr_info("Average test time: %llu\n", total_time);
739 
740 	test_insert_duplicates_run();
741 
742 	if (!tcount)
743 		return 0;
744 
745 	pr_info("Testing concurrent rhashtable access from %d threads\n",
746 	        tcount);
747 	atomic_set(&startup_count, tcount);
748 	tdata = vzalloc(array_size(tcount, sizeof(struct thread_data)));
749 	if (!tdata)
750 		return -ENOMEM;
751 	objs  = vzalloc(array3_size(sizeof(struct test_obj), tcount, entries));
752 	if (!objs) {
753 		vfree(tdata);
754 		return -ENOMEM;
755 	}
756 
757 	test_rht_params.max_size = max_size ? :
758 	                           roundup_pow_of_two(tcount * entries);
759 	err = rhashtable_init(&ht, &test_rht_params);
760 	if (err < 0) {
761 		pr_warn("Test failed: Unable to initialize hashtable: %d\n",
762 			err);
763 		vfree(tdata);
764 		vfree(objs);
765 		return -EINVAL;
766 	}
767 	for (i = 0; i < tcount; i++) {
768 		tdata[i].id = i;
769 		tdata[i].entries = entries;
770 		tdata[i].objs = objs + i * entries;
771 		tdata[i].task = kthread_run(threadfunc, &tdata[i],
772 		                            "rhashtable_thrad[%d]", i);
773 		if (IS_ERR(tdata[i].task)) {
774 			pr_err(" kthread_run failed for thread %d\n", i);
775 			atomic_dec(&startup_count);
776 		} else {
777 			started_threads++;
778 		}
779 	}
780 	if (wait_event_interruptible(startup_wait, atomic_read(&startup_count) == 0))
781 		pr_err("  wait_event interruptible failed\n");
782 	/* count is 0 now, set it to -1 and wake up all threads together */
783 	atomic_dec(&startup_count);
784 	wake_up_all(&startup_wait);
785 	for (i = 0; i < tcount; i++) {
786 		if (IS_ERR(tdata[i].task))
787 			continue;
788 		if ((err = kthread_stop(tdata[i].task))) {
789 			pr_warn("Test failed: thread %d returned: %d\n",
790 			        i, err);
791 			failed_threads++;
792 		}
793 	}
794 	rhashtable_destroy(&ht);
795 	vfree(tdata);
796 	vfree(objs);
797 
798 	/*
799 	 * rhltable_remove is very expensive, default values can cause test
800 	 * to run for 2 minutes or more,  use a smaller number instead.
801 	 */
802 	err = test_rhltable(entries / 16);
803 	pr_info("Started %d threads, %d failed, rhltable test returns %d\n",
804 	        started_threads, failed_threads, err);
805 	return 0;
806 }
807 
808 static void __exit test_rht_exit(void)
809 {
810 }
811 
812 module_init(test_rht_init);
813 module_exit(test_rht_exit);
814 
815 MODULE_LICENSE("GPL v2");
816