lib/test_rhashtable.c

   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 = 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);
 442 out_free:
 443         vfree(rhl_test_objects);
 444         vfree(obj_in_table);
 445         return ret;
 446 }
 447
 448 static 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
 485 static 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
 534 static 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
 573 skip_print:
 574         rhltable_destroy(rhlt);
 575         kfree(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         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         }
 689 out:
 690         while (!kthread_should_stop()) {
 691                 set_current_state(TASK_INTERRUPTIBLE);
 692                 schedule();
 693         }
 694         return err;
 695 }
 696
 697 static 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
 822 static void __exit test_rht_exit(void)
 823 {
 824 }
 825
 826 module_init(test_rht_init);
 827 module_exit(test_rht_exit);
 828
 829 MODULE_LICENSE("GPL v2");