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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->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, 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, &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
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, 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
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(&rhlt, &test_rht_params);
291 if (WARN_ON(err))
292 goto out_free;
293
294 k = prandom_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();
373
374 cond_resched();
375
376 if (prand == 0)
377 prand = prandom_u32();
378
379 if (prand & 1) {
380 prand >>= 1;
381 continue;
382 }
383
384 err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
385 if (test_bit(i, obj_in_table)) {
386 clear_bit(i, obj_in_table);
387 if (WARN(err, "cannot remove element at slot %d", i))
388 continue;
389 } else {
390 if (WARN(err != -ENOENT, "removed non-existent element %d, error %d not %d",
391 i, err, -ENOENT))
392 continue;
393 }
394
395 if (prand & 1) {
396 prand >>= 1;
397 continue;
398 }
399
400 err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
401 if (err == 0) {
402 if (WARN(test_and_set_bit(i, obj_in_table), "succeeded to insert same object %d", i))
403 continue;
404 } else {
405 if (WARN(!test_bit(i, obj_in_table), "failed to insert object %d", i))
406 continue;
407 }
408
409 if (prand & 1) {
410 prand >>= 1;
411 continue;
412 }
413
414 i = prandom_u32_max(entries);
415 if (test_bit(i, obj_in_table)) {
416 err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
417 WARN(err, "cannot remove element at slot %d", i);
418 if (err == 0)
419 clear_bit(i, obj_in_table);
420 } else {
421 err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
422 WARN(err, "failed to insert object %d", i);
423 if (err == 0)
424 set_bit(i, obj_in_table);
425 }
426 }
427
428 for (i = 0; i < entries; i++) {
429 cond_resched();
430 err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
431 if (test_bit(i, obj_in_table)) {
432 if (WARN(err, "cannot remove element at slot %d", i))
433 continue;
434 } else {
435 if (WARN(err != -ENOENT, "removed non-existent element, error %d not %d",
436 err, -ENOENT))
437 continue;
438 }
439 }
440
441 rhltable_destroy(&rhlt);
442out_free:
443 vfree(rhl_test_objects);
444 vfree(obj_in_table);
445 return ret;
446}
447
448static int __init test_rhashtable_max(struct test_obj *array,
449 unsigned int entries)
450{
451 unsigned int i, insert_retries = 0;
452 int err;
453
454 test_rht_params.max_size = roundup_pow_of_two(entries / 8);
455 err = rhashtable_init(&ht, &test_rht_params);
456 if (err)
457 return err;
458
459 for (i = 0; i < ht.max_elems; i++) {
460 struct test_obj *obj = &array[i];
461
462 obj->value.id = i * 2;
463 err = insert_retry(&ht, obj, test_rht_params);
464 if (err > 0)
465 insert_retries += err;
466 else if (err)
467 return err;
468 }
469
470 err = insert_retry(&ht, &array[ht.max_elems], test_rht_params);
471 if (err == -E2BIG) {
472 err = 0;
473 } else {
474 pr_info("insert element %u should have failed with %d, got %d\n",
475 ht.max_elems, -E2BIG, err);
476 if (err == 0)
477 err = -1;
478 }
479
480 rhashtable_destroy(&ht);
481
482 return err;
483}
484
485static unsigned int __init print_ht(struct rhltable *rhlt)
486{
487 struct rhashtable *ht;
488 const struct bucket_table *tbl;
489 char buff[512] = "";
490 int offset = 0;
491 unsigned int i, cnt = 0;
492
493 ht = &rhlt->ht;
494 /* Take the mutex to avoid RCU warning */
495 mutex_lock(&ht->mutex);
496 tbl = rht_dereference(ht->tbl, ht);
497 for (i = 0; i < tbl->size; i++) {
498 struct rhash_head *pos, *next;
499 struct test_obj_rhl *p;
500
501 pos = rht_ptr_exclusive(tbl->buckets + i);
502 next = !rht_is_a_nulls(pos) ? rht_dereference(pos->next, ht) : NULL;
503
504 if (!rht_is_a_nulls(pos)) {
505 offset += sprintf(buff + offset, "\nbucket[%d] -> ", i);
506 }
507
508 while (!rht_is_a_nulls(pos)) {
509 struct rhlist_head *list = container_of(pos, struct rhlist_head, rhead);
510 offset += sprintf(buff + offset, "[[");
511 do {
512 pos = &list->rhead;
513 list = rht_dereference(list->next, ht);
514 p = rht_obj(ht, pos);
515
516 offset += sprintf(buff + offset, " val %d (tid=%d)%s", p->value.id, p->value.tid,
517 list? ", " : " ");
518 cnt++;
519 } while (list);
520
521 pos = next,
522 next = !rht_is_a_nulls(pos) ?
523 rht_dereference(pos->next, ht) : NULL;
524
525 offset += sprintf(buff + offset, "]]%s", !rht_is_a_nulls(pos) ? " -> " : "");
526 }
527 }
528 printk(KERN_ERR "\n---- ht: ----%s\n-------------\n", buff);
529 mutex_unlock(&ht->mutex);
530
531 return cnt;
532}
533
534static int __init test_insert_dup(struct test_obj_rhl *rhl_test_objects,
535 int cnt, bool slow)
536{
537 struct rhltable *rhlt;
538 unsigned int i, ret;
539 const char *key;
540 int err = 0;
541
542 rhlt = kmalloc(sizeof(*rhlt), GFP_KERNEL);
543 if (WARN_ON(!rhlt))
544 return -EINVAL;
545
546 err = rhltable_init(rhlt, &test_rht_params_dup);
547 if (WARN_ON(err)) {
548 kfree(rhlt);
549 return err;
550 }
551
552 for (i = 0; i < cnt; i++) {
553 rhl_test_objects[i].value.tid = i;
554 key = rht_obj(&rhlt->ht, &rhl_test_objects[i].list_node.rhead);
555 key += test_rht_params_dup.key_offset;
556
557 if (slow) {
558 err = PTR_ERR(rhashtable_insert_slow(&rhlt->ht, key,
559 &rhl_test_objects[i].list_node.rhead));
560 if (err == -EAGAIN)
561 err = 0;
562 } else
563 err = rhltable_insert(rhlt,
564 &rhl_test_objects[i].list_node,
565 test_rht_params_dup);
566 if (WARN(err, "error %d on element %d/%d (%s)\n", err, i, cnt, slow? "slow" : "fast"))
567 goto skip_print;
568 }
569
570 ret = print_ht(rhlt);
571 WARN(ret != cnt, "missing rhltable elements (%d != %d, %s)\n", ret, cnt, slow? "slow" : "fast");
572
573skip_print:
574 rhltable_destroy(rhlt);
575 kfree(rhlt);
576
577 return 0;
578}
579
580static 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
602static 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
632static int threadfunc(void *data)
633{
634 int i, step, err = 0, insert_retries = 0;
635 struct thread_data *tdata = data;
636
637 if (atomic_dec_and_test(&startup_count))
638 wake_up(&startup_wait);
639 if (wait_event_interruptible(startup_wait, atomic_read(&startup_count) == -1)) {
640 pr_err(" thread[%d]: interrupted\n", tdata->id);
641 goto out;
642 }
643
644 for (i = 0; i < tdata->entries; i++) {
645 tdata->objs[i].value.id = i;
646 tdata->objs[i].value.tid = tdata->id;
647 err = insert_retry(&ht, &tdata->objs[i], test_rht_params);
648 if (err > 0) {
649 insert_retries += err;
650 } else if (err) {
651 pr_err(" thread[%d]: rhashtable_insert_fast failed\n",
652 tdata->id);
653 goto out;
654 }
655 }
656 if (insert_retries)
657 pr_info(" thread[%d]: %u insertions retried due to memory pressure\n",
658 tdata->id, insert_retries);
659
660 err = thread_lookup_test(tdata);
661 if (err) {
662 pr_err(" thread[%d]: rhashtable_lookup_test failed\n",
663 tdata->id);
664 goto out;
665 }
666
667 for (step = 10; step > 0; step--) {
668 for (i = 0; i < tdata->entries; i += step) {
669 if (tdata->objs[i].value.id == TEST_INSERT_FAIL)
670 continue;
671 err = rhashtable_remove_fast(&ht, &tdata->objs[i].node,
672 test_rht_params);
673 if (err) {
674 pr_err(" thread[%d]: rhashtable_remove_fast failed\n",
675 tdata->id);
676 goto out;
677 }
678 tdata->objs[i].value.id = TEST_INSERT_FAIL;
679
680 cond_resched();
681 }
682 err = thread_lookup_test(tdata);
683 if (err) {
684 pr_err(" thread[%d]: rhashtable_lookup_test (2) failed\n",
685 tdata->id);
686 goto out;
687 }
688 }
689out:
690 while (!kthread_should_stop()) {
691 set_current_state(TASK_INTERRUPTIBLE);
692 schedule();
693 }
694 return err;
695}
696
697static int __init test_rht_init(void)
698{
699 unsigned int entries;
700 int i, err, started_threads = 0, failed_threads = 0;
701 u64 total_time = 0;
702 struct thread_data *tdata;
703 struct test_obj *objs;
704
705 if (parm_entries < 0)
706 parm_entries = 1;
707
708 entries = min(parm_entries, MAX_ENTRIES);
709
710 test_rht_params.automatic_shrinking = shrinking;
711 test_rht_params.max_size = max_size ? : roundup_pow_of_two(entries);
712 test_rht_params.nelem_hint = size;
713
714 objs = vzalloc(array_size(sizeof(struct test_obj),
715 test_rht_params.max_size + 1));
716 if (!objs)
717 return -ENOMEM;
718
719 pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n",
720 size, max_size, shrinking);
721
722 for (i = 0; i < runs; i++) {
723 s64 time;
724
725 pr_info("Test %02d:\n", i);
726 memset(objs, 0, test_rht_params.max_size * sizeof(struct test_obj));
727
728 err = rhashtable_init(&ht, &test_rht_params);
729 if (err < 0) {
730 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
731 err);
732 continue;
733 }
734
735 time = test_rhashtable(&ht, objs, entries);
736 rhashtable_destroy(&ht);
737 if (time < 0) {
738 vfree(objs);
739 pr_warn("Test failed: return code %lld\n", time);
740 return -EINVAL;
741 }
742
743 total_time += time;
744 }
745
746 pr_info("test if its possible to exceed max_size %d: %s\n",
747 test_rht_params.max_size, test_rhashtable_max(objs, entries) == 0 ?
748 "no, ok" : "YES, failed");
749 vfree(objs);
750
751 do_div(total_time, runs);
752 pr_info("Average test time: %llu\n", total_time);
753
754 test_insert_duplicates_run();
755
756 if (!tcount)
757 return 0;
758
759 pr_info("Testing concurrent rhashtable access from %d threads\n",
760 tcount);
761 atomic_set(&startup_count, tcount);
762 tdata = vzalloc(array_size(tcount, sizeof(struct thread_data)));
763 if (!tdata)
764 return -ENOMEM;
765 objs = vzalloc(array3_size(sizeof(struct test_obj), tcount, entries));
766 if (!objs) {
767 vfree(tdata);
768 return -ENOMEM;
769 }
770
771 test_rht_params.max_size = max_size ? :
772 roundup_pow_of_two(tcount * entries);
773 err = rhashtable_init(&ht, &test_rht_params);
774 if (err < 0) {
775 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
776 err);
777 vfree(tdata);
778 vfree(objs);
779 return -EINVAL;
780 }
781 for (i = 0; i < tcount; i++) {
782 tdata[i].id = i;
783 tdata[i].entries = entries;
784 tdata[i].objs = objs + i * entries;
785 tdata[i].task = kthread_run(threadfunc, &tdata[i],
786 "rhashtable_thrad[%d]", i);
787 if (IS_ERR(tdata[i].task)) {
788 pr_err(" kthread_run failed for thread %d\n", i);
789 atomic_dec(&startup_count);
790 } else {
791 started_threads++;
792 }
793 }
794 if (wait_event_interruptible(startup_wait, atomic_read(&startup_count) == 0))
795 pr_err(" wait_event interruptible failed\n");
796 /* count is 0 now, set it to -1 and wake up all threads together */
797 atomic_dec(&startup_count);
798 wake_up_all(&startup_wait);
799 for (i = 0; i < tcount; i++) {
800 if (IS_ERR(tdata[i].task))
801 continue;
802 if ((err = kthread_stop(tdata[i].task))) {
803 pr_warn("Test failed: thread %d returned: %d\n",
804 i, err);
805 failed_threads++;
806 }
807 }
808 rhashtable_destroy(&ht);
809 vfree(tdata);
810 vfree(objs);
811
812 /*
813 * rhltable_remove is very expensive, default values can cause test
814 * to run for 2 minutes or more, use a smaller number instead.
815 */
816 err = test_rhltable(entries / 16);
817 pr_info("Started %d threads, %d failed, rhltable test returns %d\n",
818 started_threads, failed_threads, err);
819 return 0;
820}
821
822static void __exit test_rht_exit(void)
823{
824}
825
826module_init(test_rht_init);
827module_exit(test_rht_exit);
828
829MODULE_LICENSE("GPL v2");
1/*
2 * Resizable, Scalable, Concurrent Hash Table
3 *
4 * Copyright (c) 2014-2015 Thomas Graf <tgraf@suug.ch>
5 * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12/**************************************************************************
13 * Self Test
14 **************************************************************************/
15
16#include <linux/init.h>
17#include <linux/jhash.h>
18#include <linux/kernel.h>
19#include <linux/kthread.h>
20#include <linux/module.h>
21#include <linux/rcupdate.h>
22#include <linux/rhashtable.h>
23#include <linux/semaphore.h>
24#include <linux/slab.h>
25#include <linux/sched.h>
26#include <linux/vmalloc.h>
27
28#define MAX_ENTRIES 1000000
29#define TEST_INSERT_FAIL INT_MAX
30
31static int entries = 50000;
32module_param(entries, int, 0);
33MODULE_PARM_DESC(entries, "Number of entries to add (default: 50000)");
34
35static int runs = 4;
36module_param(runs, int, 0);
37MODULE_PARM_DESC(runs, "Number of test runs per variant (default: 4)");
38
39static int max_size = 0;
40module_param(max_size, int, 0);
41MODULE_PARM_DESC(max_size, "Maximum table size (default: calculated)");
42
43static bool shrinking = false;
44module_param(shrinking, bool, 0);
45MODULE_PARM_DESC(shrinking, "Enable automatic shrinking (default: off)");
46
47static int size = 8;
48module_param(size, int, 0);
49MODULE_PARM_DESC(size, "Initial size hint of table (default: 8)");
50
51static int tcount = 10;
52module_param(tcount, int, 0);
53MODULE_PARM_DESC(tcount, "Number of threads to spawn (default: 10)");
54
55static bool enomem_retry = false;
56module_param(enomem_retry, bool, 0);
57MODULE_PARM_DESC(enomem_retry, "Retry insert even if -ENOMEM was returned (default: off)");
58
59struct test_obj {
60 int value;
61 struct rhash_head node;
62};
63
64struct thread_data {
65 int id;
66 struct task_struct *task;
67 struct test_obj *objs;
68};
69
70static struct test_obj array[MAX_ENTRIES];
71
72static struct rhashtable_params test_rht_params = {
73 .head_offset = offsetof(struct test_obj, node),
74 .key_offset = offsetof(struct test_obj, value),
75 .key_len = sizeof(int),
76 .hashfn = jhash,
77 .nulls_base = (3U << RHT_BASE_SHIFT),
78};
79
80static struct semaphore prestart_sem;
81static struct semaphore startup_sem = __SEMAPHORE_INITIALIZER(startup_sem, 0);
82
83static int insert_retry(struct rhashtable *ht, struct rhash_head *obj,
84 const struct rhashtable_params params)
85{
86 int err, retries = -1, enomem_retries = 0;
87
88 do {
89 retries++;
90 cond_resched();
91 err = rhashtable_insert_fast(ht, obj, params);
92 if (err == -ENOMEM && enomem_retry) {
93 enomem_retries++;
94 err = -EBUSY;
95 }
96 } while (err == -EBUSY);
97
98 if (enomem_retries)
99 pr_info(" %u insertions retried after -ENOMEM\n",
100 enomem_retries);
101
102 return err ? : retries;
103}
104
105static int __init test_rht_lookup(struct rhashtable *ht)
106{
107 unsigned int i;
108
109 for (i = 0; i < entries * 2; i++) {
110 struct test_obj *obj;
111 bool expected = !(i % 2);
112 u32 key = i;
113
114 if (array[i / 2].value == TEST_INSERT_FAIL)
115 expected = false;
116
117 obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
118
119 if (expected && !obj) {
120 pr_warn("Test failed: Could not find key %u\n", key);
121 return -ENOENT;
122 } else if (!expected && obj) {
123 pr_warn("Test failed: Unexpected entry found for key %u\n",
124 key);
125 return -EEXIST;
126 } else if (expected && obj) {
127 if (obj->value != i) {
128 pr_warn("Test failed: Lookup value mismatch %u!=%u\n",
129 obj->value, i);
130 return -EINVAL;
131 }
132 }
133
134 cond_resched_rcu();
135 }
136
137 return 0;
138}
139
140static void test_bucket_stats(struct rhashtable *ht)
141{
142 unsigned int err, total = 0, chain_len = 0;
143 struct rhashtable_iter hti;
144 struct rhash_head *pos;
145
146 err = rhashtable_walk_init(ht, &hti, GFP_KERNEL);
147 if (err) {
148 pr_warn("Test failed: allocation error");
149 return;
150 }
151
152 err = rhashtable_walk_start(&hti);
153 if (err && err != -EAGAIN) {
154 pr_warn("Test failed: iterator failed: %d\n", err);
155 return;
156 }
157
158 while ((pos = rhashtable_walk_next(&hti))) {
159 if (PTR_ERR(pos) == -EAGAIN) {
160 pr_info("Info: encountered resize\n");
161 chain_len++;
162 continue;
163 } else if (IS_ERR(pos)) {
164 pr_warn("Test failed: rhashtable_walk_next() error: %ld\n",
165 PTR_ERR(pos));
166 break;
167 }
168
169 total++;
170 }
171
172 rhashtable_walk_stop(&hti);
173 rhashtable_walk_exit(&hti);
174
175 pr_info(" Traversal complete: counted=%u, nelems=%u, entries=%d, table-jumps=%u\n",
176 total, atomic_read(&ht->nelems), entries, chain_len);
177
178 if (total != atomic_read(&ht->nelems) || total != entries)
179 pr_warn("Test failed: Total count mismatch ^^^");
180}
181
182static s64 __init test_rhashtable(struct rhashtable *ht)
183{
184 struct test_obj *obj;
185 int err;
186 unsigned int i, insert_retries = 0;
187 s64 start, end;
188
189 /*
190 * Insertion Test:
191 * Insert entries into table with all keys even numbers
192 */
193 pr_info(" Adding %d keys\n", entries);
194 start = ktime_get_ns();
195 for (i = 0; i < entries; i++) {
196 struct test_obj *obj = &array[i];
197
198 obj->value = i * 2;
199 err = insert_retry(ht, &obj->node, test_rht_params);
200 if (err > 0)
201 insert_retries += err;
202 else if (err)
203 return err;
204 }
205
206 if (insert_retries)
207 pr_info(" %u insertions retried due to memory pressure\n",
208 insert_retries);
209
210 test_bucket_stats(ht);
211 rcu_read_lock();
212 test_rht_lookup(ht);
213 rcu_read_unlock();
214
215 test_bucket_stats(ht);
216
217 pr_info(" Deleting %d keys\n", entries);
218 for (i = 0; i < entries; i++) {
219 u32 key = i * 2;
220
221 if (array[i].value != TEST_INSERT_FAIL) {
222 obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
223 BUG_ON(!obj);
224
225 rhashtable_remove_fast(ht, &obj->node, test_rht_params);
226 }
227
228 cond_resched();
229 }
230
231 end = ktime_get_ns();
232 pr_info(" Duration of test: %lld ns\n", end - start);
233
234 return end - start;
235}
236
237static struct rhashtable ht;
238
239static int thread_lookup_test(struct thread_data *tdata)
240{
241 int i, err = 0;
242
243 for (i = 0; i < entries; i++) {
244 struct test_obj *obj;
245 int key = (tdata->id << 16) | i;
246
247 obj = rhashtable_lookup_fast(&ht, &key, test_rht_params);
248 if (obj && (tdata->objs[i].value == TEST_INSERT_FAIL)) {
249 pr_err(" found unexpected object %d\n", key);
250 err++;
251 } else if (!obj && (tdata->objs[i].value != TEST_INSERT_FAIL)) {
252 pr_err(" object %d not found!\n", key);
253 err++;
254 } else if (obj && (obj->value != key)) {
255 pr_err(" wrong object returned (got %d, expected %d)\n",
256 obj->value, key);
257 err++;
258 }
259
260 cond_resched();
261 }
262 return err;
263}
264
265static int threadfunc(void *data)
266{
267 int i, step, err = 0, insert_retries = 0;
268 struct thread_data *tdata = data;
269
270 up(&prestart_sem);
271 if (down_interruptible(&startup_sem))
272 pr_err(" thread[%d]: down_interruptible failed\n", tdata->id);
273
274 for (i = 0; i < entries; i++) {
275 tdata->objs[i].value = (tdata->id << 16) | i;
276 err = insert_retry(&ht, &tdata->objs[i].node, test_rht_params);
277 if (err > 0) {
278 insert_retries += err;
279 } else if (err) {
280 pr_err(" thread[%d]: rhashtable_insert_fast failed\n",
281 tdata->id);
282 goto out;
283 }
284 }
285 if (insert_retries)
286 pr_info(" thread[%d]: %u insertions retried due to memory pressure\n",
287 tdata->id, insert_retries);
288
289 err = thread_lookup_test(tdata);
290 if (err) {
291 pr_err(" thread[%d]: rhashtable_lookup_test failed\n",
292 tdata->id);
293 goto out;
294 }
295
296 for (step = 10; step > 0; step--) {
297 for (i = 0; i < entries; i += step) {
298 if (tdata->objs[i].value == TEST_INSERT_FAIL)
299 continue;
300 err = rhashtable_remove_fast(&ht, &tdata->objs[i].node,
301 test_rht_params);
302 if (err) {
303 pr_err(" thread[%d]: rhashtable_remove_fast failed\n",
304 tdata->id);
305 goto out;
306 }
307 tdata->objs[i].value = TEST_INSERT_FAIL;
308
309 cond_resched();
310 }
311 err = thread_lookup_test(tdata);
312 if (err) {
313 pr_err(" thread[%d]: rhashtable_lookup_test (2) failed\n",
314 tdata->id);
315 goto out;
316 }
317 }
318out:
319 while (!kthread_should_stop()) {
320 set_current_state(TASK_INTERRUPTIBLE);
321 schedule();
322 }
323 return err;
324}
325
326static int __init test_rht_init(void)
327{
328 int i, err, started_threads = 0, failed_threads = 0;
329 u64 total_time = 0;
330 struct thread_data *tdata;
331 struct test_obj *objs;
332
333 entries = min(entries, MAX_ENTRIES);
334
335 test_rht_params.automatic_shrinking = shrinking;
336 test_rht_params.max_size = max_size ? : roundup_pow_of_two(entries);
337 test_rht_params.nelem_hint = size;
338
339 pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n",
340 size, max_size, shrinking);
341
342 for (i = 0; i < runs; i++) {
343 s64 time;
344
345 pr_info("Test %02d:\n", i);
346 memset(&array, 0, sizeof(array));
347 err = rhashtable_init(&ht, &test_rht_params);
348 if (err < 0) {
349 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
350 err);
351 continue;
352 }
353
354 time = test_rhashtable(&ht);
355 rhashtable_destroy(&ht);
356 if (time < 0) {
357 pr_warn("Test failed: return code %lld\n", time);
358 return -EINVAL;
359 }
360
361 total_time += time;
362 }
363
364 do_div(total_time, runs);
365 pr_info("Average test time: %llu\n", total_time);
366
367 if (!tcount)
368 return 0;
369
370 pr_info("Testing concurrent rhashtable access from %d threads\n",
371 tcount);
372 sema_init(&prestart_sem, 1 - tcount);
373 tdata = vzalloc(tcount * sizeof(struct thread_data));
374 if (!tdata)
375 return -ENOMEM;
376 objs = vzalloc(tcount * entries * sizeof(struct test_obj));
377 if (!objs) {
378 vfree(tdata);
379 return -ENOMEM;
380 }
381
382 test_rht_params.max_size = max_size ? :
383 roundup_pow_of_two(tcount * entries);
384 err = rhashtable_init(&ht, &test_rht_params);
385 if (err < 0) {
386 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
387 err);
388 vfree(tdata);
389 vfree(objs);
390 return -EINVAL;
391 }
392 for (i = 0; i < tcount; i++) {
393 tdata[i].id = i;
394 tdata[i].objs = objs + i * entries;
395 tdata[i].task = kthread_run(threadfunc, &tdata[i],
396 "rhashtable_thrad[%d]", i);
397 if (IS_ERR(tdata[i].task))
398 pr_err(" kthread_run failed for thread %d\n", i);
399 else
400 started_threads++;
401 }
402 if (down_interruptible(&prestart_sem))
403 pr_err(" down interruptible failed\n");
404 for (i = 0; i < tcount; i++)
405 up(&startup_sem);
406 for (i = 0; i < tcount; i++) {
407 if (IS_ERR(tdata[i].task))
408 continue;
409 if ((err = kthread_stop(tdata[i].task))) {
410 pr_warn("Test failed: thread %d returned: %d\n",
411 i, err);
412 failed_threads++;
413 }
414 }
415 pr_info("Started %d threads, %d failed\n",
416 started_threads, failed_threads);
417 rhashtable_destroy(&ht);
418 vfree(tdata);
419 vfree(objs);
420 return 0;
421}
422
423static void __exit test_rht_exit(void)
424{
425}
426
427module_init(test_rht_init);
428module_exit(test_rht_exit);
429
430MODULE_LICENSE("GPL v2");