1
2
3
4
5
6
7
8
9
10
11
12
13
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
32static int parm_entries = 50000;
33module_param(parm_entries, int, 0);
34MODULE_PARM_DESC(parm_entries, "Number of entries to add (default: 50000)");
35
36static int runs = 4;
37module_param(runs, int, 0);
38MODULE_PARM_DESC(runs, "Number of test runs per variant (default: 4)");
39
40static int max_size = 0;
41module_param(max_size, int, 0);
42MODULE_PARM_DESC(max_size, "Maximum table size (default: calculated)");
43
44static bool shrinking = false;
45module_param(shrinking, bool, 0);
46MODULE_PARM_DESC(shrinking, "Enable automatic shrinking (default: off)");
47
48static int size = 8;
49module_param(size, int, 0);
50MODULE_PARM_DESC(size, "Initial size hint of table (default: 8)");
51
52static int tcount = 10;
53module_param(tcount, int, 0);
54MODULE_PARM_DESC(tcount, "Number of threads to spawn (default: 10)");
55
56static bool enomem_retry = false;
57module_param(enomem_retry, bool, 0);
58MODULE_PARM_DESC(enomem_retry, "Retry insert even if -ENOMEM was returned (default: off)");
59
60struct test_obj_val {
61 int id;
62 int tid;
63};
64
65struct test_obj {
66 struct test_obj_val value;
67 struct rhash_head node;
68};
69
70struct test_obj_rhl {
71 struct test_obj_val value;
72 struct rhlist_head list_node;
73};
74
75struct thread_data {
76 unsigned int entries;
77 int id;
78 struct task_struct *task;
79 struct test_obj *objs;
80};
81
82static struct rhashtable_params test_rht_params = {
83 .head_offset = offsetof(struct test_obj, node),
84 .key_offset = offsetof(struct test_obj, value),
85 .key_len = sizeof(struct test_obj_val),
86 .hashfn = jhash,
87 .nulls_base = (3U << RHT_BASE_SHIFT),
88};
89
90static struct semaphore prestart_sem;
91static struct semaphore startup_sem = __SEMAPHORE_INITIALIZER(startup_sem, 0);
92
93static int insert_retry(struct rhashtable *ht, struct test_obj *obj,
94 const struct rhashtable_params params)
95{
96 int err, retries = -1, enomem_retries = 0;
97
98 do {
99 retries++;
100 cond_resched();
101 err = rhashtable_insert_fast(ht, &obj->node, params);
102 if (err == -ENOMEM && enomem_retry) {
103 enomem_retries++;
104 err = -EBUSY;
105 }
106 } while (err == -EBUSY);
107
108 if (enomem_retries)
109 pr_info(" %u insertions retried after -ENOMEM\n",
110 enomem_retries);
111
112 return err ? : retries;
113}
114
115static int __init test_rht_lookup(struct rhashtable *ht, struct test_obj *array,
116 unsigned int entries)
117{
118 unsigned int i;
119
120 for (i = 0; i < entries; i++) {
121 struct test_obj *obj;
122 bool expected = !(i % 2);
123 struct test_obj_val key = {
124 .id = i,
125 };
126
127 if (array[i / 2].value.id == TEST_INSERT_FAIL)
128 expected = false;
129
130 obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
131
132 if (expected && !obj) {
133 pr_warn("Test failed: Could not find key %u\n", key.id);
134 return -ENOENT;
135 } else if (!expected && obj) {
136 pr_warn("Test failed: Unexpected entry found for key %u\n",
137 key.id);
138 return -EEXIST;
139 } else if (expected && obj) {
140 if (obj->value.id != i) {
141 pr_warn("Test failed: Lookup value mismatch %u!=%u\n",
142 obj->value.id, i);
143 return -EINVAL;
144 }
145 }
146
147 cond_resched_rcu();
148 }
149
150 return 0;
151}
152
153static void test_bucket_stats(struct rhashtable *ht, unsigned int entries)
154{
155 unsigned int err, total = 0, chain_len = 0;
156 struct rhashtable_iter hti;
157 struct rhash_head *pos;
158
159 err = rhashtable_walk_init(ht, &hti, GFP_KERNEL);
160 if (err) {
161 pr_warn("Test failed: allocation error");
162 return;
163 }
164
165 err = rhashtable_walk_start(&hti);
166 if (err && err != -EAGAIN) {
167 pr_warn("Test failed: iterator failed: %d\n", err);
168 return;
169 }
170
171 while ((pos = rhashtable_walk_next(&hti))) {
172 if (PTR_ERR(pos) == -EAGAIN) {
173 pr_info("Info: encountered resize\n");
174 chain_len++;
175 continue;
176 } else if (IS_ERR(pos)) {
177 pr_warn("Test failed: rhashtable_walk_next() error: %ld\n",
178 PTR_ERR(pos));
179 break;
180 }
181
182 total++;
183 }
184
185 rhashtable_walk_stop(&hti);
186 rhashtable_walk_exit(&hti);
187
188 pr_info(" Traversal complete: counted=%u, nelems=%u, entries=%d, table-jumps=%u\n",
189 total, atomic_read(&ht->nelems), entries, chain_len);
190
191 if (total != atomic_read(&ht->nelems) || total != entries)
192 pr_warn("Test failed: Total count mismatch ^^^");
193}
194
195static s64 __init test_rhashtable(struct rhashtable *ht, struct test_obj *array,
196 unsigned int entries)
197{
198 struct test_obj *obj;
199 int err;
200 unsigned int i, insert_retries = 0;
201 s64 start, end;
202
203
204
205
206
207 pr_info(" Adding %d keys\n", entries);
208 start = ktime_get_ns();
209 for (i = 0; i < entries; i++) {
210 struct test_obj *obj = &array[i];
211
212 obj->value.id = i * 2;
213 err = insert_retry(ht, obj, test_rht_params);
214 if (err > 0)
215 insert_retries += err;
216 else if (err)
217 return err;
218 }
219
220 if (insert_retries)
221 pr_info(" %u insertions retried due to memory pressure\n",
222 insert_retries);
223
224 test_bucket_stats(ht, entries);
225 rcu_read_lock();
226 test_rht_lookup(ht, array, entries);
227 rcu_read_unlock();
228
229 test_bucket_stats(ht, entries);
230
231 pr_info(" Deleting %d keys\n", entries);
232 for (i = 0; i < entries; i++) {
233 struct test_obj_val key = {
234 .id = i * 2,
235 };
236
237 if (array[i].value.id != TEST_INSERT_FAIL) {
238 obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
239 BUG_ON(!obj);
240
241 rhashtable_remove_fast(ht, &obj->node, test_rht_params);
242 }
243
244 cond_resched();
245 }
246
247 end = ktime_get_ns();
248 pr_info(" Duration of test: %lld ns\n", end - start);
249
250 return end - start;
251}
252
253static struct rhashtable ht;
254static struct rhltable rhlt;
255
256static int __init test_rhltable(unsigned int entries)
257{
258 struct test_obj_rhl *rhl_test_objects;
259 unsigned long *obj_in_table;
260 unsigned int i, j, k;
261 int ret, err;
262
263 if (entries == 0)
264 entries = 1;
265
266 rhl_test_objects = vzalloc(sizeof(*rhl_test_objects) * entries);
267 if (!rhl_test_objects)
268 return -ENOMEM;
269
270 ret = -ENOMEM;
271 obj_in_table = vzalloc(BITS_TO_LONGS(entries) * sizeof(unsigned long));
272 if (!obj_in_table)
273 goto out_free;
274
275
276 test_rht_params.nulls_base = 0;
277 err = rhltable_init(&rhlt, &test_rht_params);
278 if (WARN_ON(err))
279 goto out_free;
280
281 k = prandom_u32();
282 ret = 0;
283 for (i = 0; i < entries; i++) {
284 rhl_test_objects[i].value.id = k;
285 err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node,
286 test_rht_params);
287 if (WARN(err, "error %d on element %d\n", err, i))
288 break;
289 if (err == 0)
290 set_bit(i, obj_in_table);
291 }
292
293 if (err)
294 ret = err;
295
296 pr_info("test %d add/delete pairs into rhlist\n", entries);
297 for (i = 0; i < entries; i++) {
298 struct rhlist_head *h, *pos;
299 struct test_obj_rhl *obj;
300 struct test_obj_val key = {
301 .id = k,
302 };
303 bool found;
304
305 rcu_read_lock();
306 h = rhltable_lookup(&rhlt, &key, test_rht_params);
307 if (WARN(!h, "key not found during iteration %d of %d", i, entries)) {
308 rcu_read_unlock();
309 break;
310 }
311
312 if (i) {
313 j = i - 1;
314 rhl_for_each_entry_rcu(obj, pos, h, list_node) {
315 if (WARN(pos == &rhl_test_objects[j].list_node, "old element found, should be gone"))
316 break;
317 }
318 }
319
320 cond_resched_rcu();
321
322 found = false;
323
324 rhl_for_each_entry_rcu(obj, pos, h, list_node) {
325 if (pos == &rhl_test_objects[i].list_node) {
326 found = true;
327 break;
328 }
329 }
330
331 rcu_read_unlock();
332
333 if (WARN(!found, "element %d not found", i))
334 break;
335
336 err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
337 WARN(err, "rhltable_remove: err %d for iteration %d\n", err, i);
338 if (err == 0)
339 clear_bit(i, obj_in_table);
340 }
341
342 if (ret == 0 && err)
343 ret = err;
344
345 for (i = 0; i < entries; i++) {
346 WARN(test_bit(i, obj_in_table), "elem %d allegedly still present", i);
347
348 err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node,
349 test_rht_params);
350 if (WARN(err, "error %d on element %d\n", err, i))
351 break;
352 if (err == 0)
353 set_bit(i, obj_in_table);
354 }
355
356 pr_info("test %d random rhlist add/delete operations\n", entries);
357 for (j = 0; j < entries; j++) {
358 u32 i = prandom_u32_max(entries);
359 u32 prand = prandom_u32();
360
361 cond_resched();
362
363 if (prand == 0)
364 prand = prandom_u32();
365
366 if (prand & 1) {
367 prand >>= 1;
368 continue;
369 }
370
371 err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
372 if (test_bit(i, obj_in_table)) {
373 clear_bit(i, obj_in_table);
374 if (WARN(err, "cannot remove element at slot %d", i))
375 continue;
376 } else {
377 if (WARN(err != -ENOENT, "removed non-existant element %d, error %d not %d",
378 i, err, -ENOENT))
379 continue;
380 }
381
382 if (prand & 1) {
383 prand >>= 1;
384 continue;
385 }
386
387 err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
388 if (err == 0) {
389 if (WARN(test_and_set_bit(i, obj_in_table), "succeeded to insert same object %d", i))
390 continue;
391 } else {
392 if (WARN(!test_bit(i, obj_in_table), "failed to insert object %d", i))
393 continue;
394 }
395
396 if (prand & 1) {
397 prand >>= 1;
398 continue;
399 }
400
401 i = prandom_u32_max(entries);
402 if (test_bit(i, obj_in_table)) {
403 err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
404 WARN(err, "cannot remove element at slot %d", i);
405 if (err == 0)
406 clear_bit(i, obj_in_table);
407 } else {
408 err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
409 WARN(err, "failed to insert object %d", i);
410 if (err == 0)
411 set_bit(i, obj_in_table);
412 }
413 }
414
415 for (i = 0; i < entries; i++) {
416 cond_resched();
417 err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params);
418 if (test_bit(i, obj_in_table)) {
419 if (WARN(err, "cannot remove element at slot %d", i))
420 continue;
421 } else {
422 if (WARN(err != -ENOENT, "removed non-existant element, error %d not %d",
423 err, -ENOENT))
424 continue;
425 }
426 }
427
428 rhltable_destroy(&rhlt);
429out_free:
430 vfree(rhl_test_objects);
431 vfree(obj_in_table);
432 return ret;
433}
434
435static int __init test_rhashtable_max(struct test_obj *array,
436 unsigned int entries)
437{
438 unsigned int i, insert_retries = 0;
439 int err;
440
441 test_rht_params.max_size = roundup_pow_of_two(entries / 8);
442 err = rhashtable_init(&ht, &test_rht_params);
443 if (err)
444 return err;
445
446 for (i = 0; i < ht.max_elems; i++) {
447 struct test_obj *obj = &array[i];
448
449 obj->value.id = i * 2;
450 err = insert_retry(&ht, obj, test_rht_params);
451 if (err > 0)
452 insert_retries += err;
453 else if (err)
454 return err;
455 }
456
457 err = insert_retry(&ht, &array[ht.max_elems], test_rht_params);
458 if (err == -E2BIG) {
459 err = 0;
460 } else {
461 pr_info("insert element %u should have failed with %d, got %d\n",
462 ht.max_elems, -E2BIG, err);
463 if (err == 0)
464 err = -1;
465 }
466
467 rhashtable_destroy(&ht);
468
469 return err;
470}
471
472static int thread_lookup_test(struct thread_data *tdata)
473{
474 unsigned int entries = tdata->entries;
475 int i, err = 0;
476
477 for (i = 0; i < entries; i++) {
478 struct test_obj *obj;
479 struct test_obj_val key = {
480 .id = i,
481 .tid = tdata->id,
482 };
483
484 obj = rhashtable_lookup_fast(&ht, &key, test_rht_params);
485 if (obj && (tdata->objs[i].value.id == TEST_INSERT_FAIL)) {
486 pr_err(" found unexpected object %d-%d\n", key.tid, key.id);
487 err++;
488 } else if (!obj && (tdata->objs[i].value.id != TEST_INSERT_FAIL)) {
489 pr_err(" object %d-%d not found!\n", key.tid, key.id);
490 err++;
491 } else if (obj && memcmp(&obj->value, &key, sizeof(key))) {
492 pr_err(" wrong object returned (got %d-%d, expected %d-%d)\n",
493 obj->value.tid, obj->value.id, key.tid, key.id);
494 err++;
495 }
496
497 cond_resched();
498 }
499 return err;
500}
501
502static int threadfunc(void *data)
503{
504 int i, step, err = 0, insert_retries = 0;
505 struct thread_data *tdata = data;
506
507 up(&prestart_sem);
508 if (down_interruptible(&startup_sem))
509 pr_err(" thread[%d]: down_interruptible failed\n", tdata->id);
510
511 for (i = 0; i < tdata->entries; i++) {
512 tdata->objs[i].value.id = i;
513 tdata->objs[i].value.tid = tdata->id;
514 err = insert_retry(&ht, &tdata->objs[i], test_rht_params);
515 if (err > 0) {
516 insert_retries += err;
517 } else if (err) {
518 pr_err(" thread[%d]: rhashtable_insert_fast failed\n",
519 tdata->id);
520 goto out;
521 }
522 }
523 if (insert_retries)
524 pr_info(" thread[%d]: %u insertions retried due to memory pressure\n",
525 tdata->id, insert_retries);
526
527 err = thread_lookup_test(tdata);
528 if (err) {
529 pr_err(" thread[%d]: rhashtable_lookup_test failed\n",
530 tdata->id);
531 goto out;
532 }
533
534 for (step = 10; step > 0; step--) {
535 for (i = 0; i < tdata->entries; i += step) {
536 if (tdata->objs[i].value.id == TEST_INSERT_FAIL)
537 continue;
538 err = rhashtable_remove_fast(&ht, &tdata->objs[i].node,
539 test_rht_params);
540 if (err) {
541 pr_err(" thread[%d]: rhashtable_remove_fast failed\n",
542 tdata->id);
543 goto out;
544 }
545 tdata->objs[i].value.id = TEST_INSERT_FAIL;
546
547 cond_resched();
548 }
549 err = thread_lookup_test(tdata);
550 if (err) {
551 pr_err(" thread[%d]: rhashtable_lookup_test (2) failed\n",
552 tdata->id);
553 goto out;
554 }
555 }
556out:
557 while (!kthread_should_stop()) {
558 set_current_state(TASK_INTERRUPTIBLE);
559 schedule();
560 }
561 return err;
562}
563
564static int __init test_rht_init(void)
565{
566 unsigned int entries;
567 int i, err, started_threads = 0, failed_threads = 0;
568 u64 total_time = 0;
569 struct thread_data *tdata;
570 struct test_obj *objs;
571
572 if (parm_entries < 0)
573 parm_entries = 1;
574
575 entries = min(parm_entries, MAX_ENTRIES);
576
577 test_rht_params.automatic_shrinking = shrinking;
578 test_rht_params.max_size = max_size ? : roundup_pow_of_two(entries);
579 test_rht_params.nelem_hint = size;
580
581 objs = vzalloc((test_rht_params.max_size + 1) * sizeof(struct test_obj));
582 if (!objs)
583 return -ENOMEM;
584
585 pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n",
586 size, max_size, shrinking);
587
588 for (i = 0; i < runs; i++) {
589 s64 time;
590
591 pr_info("Test %02d:\n", i);
592 memset(objs, 0, test_rht_params.max_size * sizeof(struct test_obj));
593
594 err = rhashtable_init(&ht, &test_rht_params);
595 if (err < 0) {
596 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
597 err);
598 continue;
599 }
600
601 time = test_rhashtable(&ht, objs, entries);
602 rhashtable_destroy(&ht);
603 if (time < 0) {
604 vfree(objs);
605 pr_warn("Test failed: return code %lld\n", time);
606 return -EINVAL;
607 }
608
609 total_time += time;
610 }
611
612 pr_info("test if its possible to exceed max_size %d: %s\n",
613 test_rht_params.max_size, test_rhashtable_max(objs, entries) == 0 ?
614 "no, ok" : "YES, failed");
615 vfree(objs);
616
617 do_div(total_time, runs);
618 pr_info("Average test time: %llu\n", total_time);
619
620 if (!tcount)
621 return 0;
622
623 pr_info("Testing concurrent rhashtable access from %d threads\n",
624 tcount);
625 sema_init(&prestart_sem, 1 - tcount);
626 tdata = vzalloc(tcount * sizeof(struct thread_data));
627 if (!tdata)
628 return -ENOMEM;
629 objs = vzalloc(tcount * entries * sizeof(struct test_obj));
630 if (!objs) {
631 vfree(tdata);
632 return -ENOMEM;
633 }
634
635 test_rht_params.max_size = max_size ? :
636 roundup_pow_of_two(tcount * entries);
637 err = rhashtable_init(&ht, &test_rht_params);
638 if (err < 0) {
639 pr_warn("Test failed: Unable to initialize hashtable: %d\n",
640 err);
641 vfree(tdata);
642 vfree(objs);
643 return -EINVAL;
644 }
645 for (i = 0; i < tcount; i++) {
646 tdata[i].id = i;
647 tdata[i].entries = entries;
648 tdata[i].objs = objs + i * entries;
649 tdata[i].task = kthread_run(threadfunc, &tdata[i],
650 "rhashtable_thrad[%d]", i);
651 if (IS_ERR(tdata[i].task))
652 pr_err(" kthread_run failed for thread %d\n", i);
653 else
654 started_threads++;
655 }
656 if (down_interruptible(&prestart_sem))
657 pr_err(" down interruptible failed\n");
658 for (i = 0; i < tcount; i++)
659 up(&startup_sem);
660 for (i = 0; i < tcount; i++) {
661 if (IS_ERR(tdata[i].task))
662 continue;
663 if ((err = kthread_stop(tdata[i].task))) {
664 pr_warn("Test failed: thread %d returned: %d\n",
665 i, err);
666 failed_threads++;
667 }
668 }
669 rhashtable_destroy(&ht);
670 vfree(tdata);
671 vfree(objs);
672
673
674
675
676
677 err = test_rhltable(entries / 16);
678 pr_info("Started %d threads, %d failed, rhltable test returns %d\n",
679 started_threads, failed_threads, err);
680 return 0;
681}
682
683static void __exit test_rht_exit(void)
684{
685}
686
687module_init(test_rht_init);
688module_exit(test_rht_exit);
689
690MODULE_LICENSE("GPL v2");
691
