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 = 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");