| 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 | |
| 31 | static int parm_entries = 50000; |
| 32 | module_param(parm_entries, int, 0); |
| 33 | MODULE_PARM_DESC(parm_entries, "Number of entries to add (default: 50000)"); |
| 34 | |
| 35 | static int runs = 4; |
| 36 | module_param(runs, int, 0); |
| 37 | MODULE_PARM_DESC(runs, "Number of test runs per variant (default: 4)"); |
| 38 | |
| 39 | static int max_size = 0; |
| 40 | module_param(max_size, int, 0); |
| 41 | MODULE_PARM_DESC(max_size, "Maximum table size (default: calculated)"); |
| 42 | |
| 43 | static bool shrinking = false; |
| 44 | module_param(shrinking, bool, 0); |
| 45 | MODULE_PARM_DESC(shrinking, "Enable automatic shrinking (default: off)"); |
| 46 | |
| 47 | static int size = 8; |
| 48 | module_param(size, int, 0); |
| 49 | MODULE_PARM_DESC(size, "Initial size hint of table (default: 8)"); |
| 50 | |
| 51 | static int tcount = 10; |
| 52 | module_param(tcount, int, 0); |
| 53 | MODULE_PARM_DESC(tcount, "Number of threads to spawn (default: 10)"); |
| 54 | |
| 55 | static bool enomem_retry = false; |
| 56 | module_param(enomem_retry, bool, 0); |
| 57 | MODULE_PARM_DESC(enomem_retry, "Retry insert even if -ENOMEM was returned (default: off)"); |
| 58 | |
| 59 | struct test_obj_val { |
| 60 | int id; |
| 61 | int tid; |
| 62 | }; |
| 63 | |
| 64 | struct test_obj { |
| 65 | struct test_obj_val value; |
| 66 | struct rhash_head node; |
| 67 | }; |
| 68 | |
| 69 | struct thread_data { |
| 70 | unsigned int entries; |
| 71 | int id; |
| 72 | struct task_struct *task; |
| 73 | struct test_obj *objs; |
| 74 | }; |
| 75 | |
| 76 | static struct rhashtable_params test_rht_params = { |
| 77 | .head_offset = offsetof(struct test_obj, node), |
| 78 | .key_offset = offsetof(struct test_obj, value), |
| 79 | .key_len = sizeof(struct test_obj_val), |
| 80 | .hashfn = jhash, |
| 81 | .nulls_base = (3U << RHT_BASE_SHIFT), |
| 82 | }; |
| 83 | |
| 84 | static struct semaphore prestart_sem; |
| 85 | static struct semaphore startup_sem = __SEMAPHORE_INITIALIZER(startup_sem, 0); |
| 86 | |
| 87 | static int insert_retry(struct rhashtable *ht, struct test_obj *obj, |
| 88 | const struct rhashtable_params params) |
| 89 | { |
| 90 | int err, retries = -1, enomem_retries = 0; |
| 91 | |
| 92 | do { |
| 93 | retries++; |
| 94 | cond_resched(); |
| 95 | err = rhashtable_insert_fast(ht, &obj->node, params); |
| 96 | if (err == -ENOMEM && enomem_retry) { |
| 97 | enomem_retries++; |
| 98 | err = -EBUSY; |
| 99 | } |
| 100 | } while (err == -EBUSY); |
| 101 | |
| 102 | if (enomem_retries) |
| 103 | pr_info(" %u insertions retried after -ENOMEM\n", |
| 104 | enomem_retries); |
| 105 | |
| 106 | return err ? : retries; |
| 107 | } |
| 108 | |
| 109 | static int __init test_rht_lookup(struct rhashtable *ht, struct test_obj *array, |
| 110 | unsigned int entries) |
| 111 | { |
| 112 | unsigned int i; |
| 113 | |
| 114 | for (i = 0; i < entries; i++) { |
| 115 | struct test_obj *obj; |
| 116 | bool expected = !(i % 2); |
| 117 | struct test_obj_val key = { |
| 118 | .id = i, |
| 119 | }; |
| 120 | |
| 121 | if (array[i / 2].value.id == TEST_INSERT_FAIL) |
| 122 | expected = false; |
| 123 | |
| 124 | obj = rhashtable_lookup_fast(ht, &key, test_rht_params); |
| 125 | |
| 126 | if (expected && !obj) { |
| 127 | pr_warn("Test failed: Could not find key %u\n", key.id); |
| 128 | return -ENOENT; |
| 129 | } else if (!expected && obj) { |
| 130 | pr_warn("Test failed: Unexpected entry found for key %u\n", |
| 131 | key.id); |
| 132 | return -EEXIST; |
| 133 | } else if (expected && obj) { |
| 134 | if (obj->value.id != i) { |
| 135 | pr_warn("Test failed: Lookup value mismatch %u!=%u\n", |
| 136 | obj->value.id, i); |
| 137 | return -EINVAL; |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | cond_resched_rcu(); |
| 142 | } |
| 143 | |
| 144 | return 0; |
| 145 | } |
| 146 | |
| 147 | static void test_bucket_stats(struct rhashtable *ht, unsigned int entries) |
| 148 | { |
| 149 | unsigned int err, total = 0, chain_len = 0; |
| 150 | struct rhashtable_iter hti; |
| 151 | struct rhash_head *pos; |
| 152 | |
| 153 | err = rhashtable_walk_init(ht, &hti, GFP_KERNEL); |
| 154 | if (err) { |
| 155 | pr_warn("Test failed: allocation error"); |
| 156 | return; |
| 157 | } |
| 158 | |
| 159 | err = rhashtable_walk_start(&hti); |
| 160 | if (err && err != -EAGAIN) { |
| 161 | pr_warn("Test failed: iterator failed: %d\n", err); |
| 162 | return; |
| 163 | } |
| 164 | |
| 165 | while ((pos = rhashtable_walk_next(&hti))) { |
| 166 | if (PTR_ERR(pos) == -EAGAIN) { |
| 167 | pr_info("Info: encountered resize\n"); |
| 168 | chain_len++; |
| 169 | continue; |
| 170 | } else if (IS_ERR(pos)) { |
| 171 | pr_warn("Test failed: rhashtable_walk_next() error: %ld\n", |
| 172 | PTR_ERR(pos)); |
| 173 | break; |
| 174 | } |
| 175 | |
| 176 | total++; |
| 177 | } |
| 178 | |
| 179 | rhashtable_walk_stop(&hti); |
| 180 | rhashtable_walk_exit(&hti); |
| 181 | |
| 182 | pr_info(" Traversal complete: counted=%u, nelems=%u, entries=%d, table-jumps=%u\n", |
| 183 | total, atomic_read(&ht->nelems), entries, chain_len); |
| 184 | |
| 185 | if (total != atomic_read(&ht->nelems) || total != entries) |
| 186 | pr_warn("Test failed: Total count mismatch ^^^"); |
| 187 | } |
| 188 | |
| 189 | static s64 __init test_rhashtable(struct rhashtable *ht, struct test_obj *array, |
| 190 | unsigned int entries) |
| 191 | { |
| 192 | struct test_obj *obj; |
| 193 | int err; |
| 194 | unsigned int i, insert_retries = 0; |
| 195 | s64 start, end; |
| 196 | |
| 197 | /* |
| 198 | * Insertion Test: |
| 199 | * Insert entries into table with all keys even numbers |
| 200 | */ |
| 201 | pr_info(" Adding %d keys\n", entries); |
| 202 | start = ktime_get_ns(); |
| 203 | for (i = 0; i < entries; i++) { |
| 204 | struct test_obj *obj = &array[i]; |
| 205 | |
| 206 | obj->value.id = i * 2; |
| 207 | err = insert_retry(ht, obj, test_rht_params); |
| 208 | if (err > 0) |
| 209 | insert_retries += err; |
| 210 | else if (err) |
| 211 | return err; |
| 212 | } |
| 213 | |
| 214 | if (insert_retries) |
| 215 | pr_info(" %u insertions retried due to memory pressure\n", |
| 216 | insert_retries); |
| 217 | |
| 218 | test_bucket_stats(ht, entries); |
| 219 | rcu_read_lock(); |
| 220 | test_rht_lookup(ht, array, entries); |
| 221 | rcu_read_unlock(); |
| 222 | |
| 223 | test_bucket_stats(ht, entries); |
| 224 | |
| 225 | pr_info(" Deleting %d keys\n", entries); |
| 226 | for (i = 0; i < entries; i++) { |
| 227 | struct test_obj_val key = { |
| 228 | .id = i * 2, |
| 229 | }; |
| 230 | |
| 231 | if (array[i].value.id != TEST_INSERT_FAIL) { |
| 232 | obj = rhashtable_lookup_fast(ht, &key, test_rht_params); |
| 233 | BUG_ON(!obj); |
| 234 | |
| 235 | rhashtable_remove_fast(ht, &obj->node, test_rht_params); |
| 236 | } |
| 237 | |
| 238 | cond_resched(); |
| 239 | } |
| 240 | |
| 241 | end = ktime_get_ns(); |
| 242 | pr_info(" Duration of test: %lld ns\n", end - start); |
| 243 | |
| 244 | return end - start; |
| 245 | } |
| 246 | |
| 247 | static struct rhashtable ht; |
| 248 | |
| 249 | static int __init test_rhashtable_max(struct test_obj *array, |
| 250 | unsigned int entries) |
| 251 | { |
| 252 | unsigned int i, insert_retries = 0; |
| 253 | int err; |
| 254 | |
| 255 | test_rht_params.max_size = roundup_pow_of_two(entries / 8); |
| 256 | err = rhashtable_init(&ht, &test_rht_params); |
| 257 | if (err) |
| 258 | return err; |
| 259 | |
| 260 | for (i = 0; i < ht.max_elems; i++) { |
| 261 | struct test_obj *obj = &array[i]; |
| 262 | |
| 263 | obj->value.id = i * 2; |
| 264 | err = insert_retry(&ht, obj, test_rht_params); |
| 265 | if (err > 0) |
| 266 | insert_retries += err; |
| 267 | else if (err) |
| 268 | return err; |
| 269 | } |
| 270 | |
| 271 | err = insert_retry(&ht, &array[ht.max_elems], test_rht_params); |
| 272 | if (err == -E2BIG) { |
| 273 | err = 0; |
| 274 | } else { |
| 275 | pr_info("insert element %u should have failed with %d, got %d\n", |
| 276 | ht.max_elems, -E2BIG, err); |
| 277 | if (err == 0) |
| 278 | err = -1; |
| 279 | } |
| 280 | |
| 281 | rhashtable_destroy(&ht); |
| 282 | |
| 283 | return err; |
| 284 | } |
| 285 | |
| 286 | static int thread_lookup_test(struct thread_data *tdata) |
| 287 | { |
| 288 | unsigned int entries = tdata->entries; |
| 289 | int i, err = 0; |
| 290 | |
| 291 | for (i = 0; i < entries; i++) { |
| 292 | struct test_obj *obj; |
| 293 | struct test_obj_val key = { |
| 294 | .id = i, |
| 295 | .tid = tdata->id, |
| 296 | }; |
| 297 | |
| 298 | obj = rhashtable_lookup_fast(&ht, &key, test_rht_params); |
| 299 | if (obj && (tdata->objs[i].value.id == TEST_INSERT_FAIL)) { |
| 300 | pr_err(" found unexpected object %d-%d\n", key.tid, key.id); |
| 301 | err++; |
| 302 | } else if (!obj && (tdata->objs[i].value.id != TEST_INSERT_FAIL)) { |
| 303 | pr_err(" object %d-%d not found!\n", key.tid, key.id); |
| 304 | err++; |
| 305 | } else if (obj && memcmp(&obj->value, &key, sizeof(key))) { |
| 306 | pr_err(" wrong object returned (got %d-%d, expected %d-%d)\n", |
| 307 | obj->value.tid, obj->value.id, key.tid, key.id); |
| 308 | err++; |
| 309 | } |
| 310 | |
| 311 | cond_resched(); |
| 312 | } |
| 313 | return err; |
| 314 | } |
| 315 | |
| 316 | static int threadfunc(void *data) |
| 317 | { |
| 318 | int i, step, err = 0, insert_retries = 0; |
| 319 | struct thread_data *tdata = data; |
| 320 | |
| 321 | up(&prestart_sem); |
| 322 | if (down_interruptible(&startup_sem)) |
| 323 | pr_err(" thread[%d]: down_interruptible failed\n", tdata->id); |
| 324 | |
| 325 | for (i = 0; i < tdata->entries; i++) { |
| 326 | tdata->objs[i].value.id = i; |
| 327 | tdata->objs[i].value.tid = tdata->id; |
| 328 | err = insert_retry(&ht, &tdata->objs[i], test_rht_params); |
| 329 | if (err > 0) { |
| 330 | insert_retries += err; |
| 331 | } else if (err) { |
| 332 | pr_err(" thread[%d]: rhashtable_insert_fast failed\n", |
| 333 | tdata->id); |
| 334 | goto out; |
| 335 | } |
| 336 | } |
| 337 | if (insert_retries) |
| 338 | pr_info(" thread[%d]: %u insertions retried due to memory pressure\n", |
| 339 | tdata->id, insert_retries); |
| 340 | |
| 341 | err = thread_lookup_test(tdata); |
| 342 | if (err) { |
| 343 | pr_err(" thread[%d]: rhashtable_lookup_test failed\n", |
| 344 | tdata->id); |
| 345 | goto out; |
| 346 | } |
| 347 | |
| 348 | for (step = 10; step > 0; step--) { |
| 349 | for (i = 0; i < tdata->entries; i += step) { |
| 350 | if (tdata->objs[i].value.id == TEST_INSERT_FAIL) |
| 351 | continue; |
| 352 | err = rhashtable_remove_fast(&ht, &tdata->objs[i].node, |
| 353 | test_rht_params); |
| 354 | if (err) { |
| 355 | pr_err(" thread[%d]: rhashtable_remove_fast failed\n", |
| 356 | tdata->id); |
| 357 | goto out; |
| 358 | } |
| 359 | tdata->objs[i].value.id = TEST_INSERT_FAIL; |
| 360 | |
| 361 | cond_resched(); |
| 362 | } |
| 363 | err = thread_lookup_test(tdata); |
| 364 | if (err) { |
| 365 | pr_err(" thread[%d]: rhashtable_lookup_test (2) failed\n", |
| 366 | tdata->id); |
| 367 | goto out; |
| 368 | } |
| 369 | } |
| 370 | out: |
| 371 | while (!kthread_should_stop()) { |
| 372 | set_current_state(TASK_INTERRUPTIBLE); |
| 373 | schedule(); |
| 374 | } |
| 375 | return err; |
| 376 | } |
| 377 | |
| 378 | static int __init test_rht_init(void) |
| 379 | { |
| 380 | unsigned int entries; |
| 381 | int i, err, started_threads = 0, failed_threads = 0; |
| 382 | u64 total_time = 0; |
| 383 | struct thread_data *tdata; |
| 384 | struct test_obj *objs; |
| 385 | |
| 386 | if (parm_entries < 0) |
| 387 | parm_entries = 1; |
| 388 | |
| 389 | entries = min(parm_entries, MAX_ENTRIES); |
| 390 | |
| 391 | test_rht_params.automatic_shrinking = shrinking; |
| 392 | test_rht_params.max_size = max_size ? : roundup_pow_of_two(entries); |
| 393 | test_rht_params.nelem_hint = size; |
| 394 | |
| 395 | objs = vzalloc((test_rht_params.max_size + 1) * sizeof(struct test_obj)); |
| 396 | if (!objs) |
| 397 | return -ENOMEM; |
| 398 | |
| 399 | pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n", |
| 400 | size, max_size, shrinking); |
| 401 | |
| 402 | for (i = 0; i < runs; i++) { |
| 403 | s64 time; |
| 404 | |
| 405 | pr_info("Test %02d:\n", i); |
| 406 | memset(objs, 0, test_rht_params.max_size * sizeof(struct test_obj)); |
| 407 | |
| 408 | err = rhashtable_init(&ht, &test_rht_params); |
| 409 | if (err < 0) { |
| 410 | pr_warn("Test failed: Unable to initialize hashtable: %d\n", |
| 411 | err); |
| 412 | continue; |
| 413 | } |
| 414 | |
| 415 | time = test_rhashtable(&ht, objs, entries); |
| 416 | rhashtable_destroy(&ht); |
| 417 | if (time < 0) { |
| 418 | vfree(objs); |
| 419 | pr_warn("Test failed: return code %lld\n", time); |
| 420 | return -EINVAL; |
| 421 | } |
| 422 | |
| 423 | total_time += time; |
| 424 | } |
| 425 | |
| 426 | pr_info("test if its possible to exceed max_size %d: %s\n", |
| 427 | test_rht_params.max_size, test_rhashtable_max(objs, entries) == 0 ? |
| 428 | "no, ok" : "YES, failed"); |
| 429 | vfree(objs); |
| 430 | |
| 431 | do_div(total_time, runs); |
| 432 | pr_info("Average test time: %llu\n", total_time); |
| 433 | |
| 434 | if (!tcount) |
| 435 | return 0; |
| 436 | |
| 437 | pr_info("Testing concurrent rhashtable access from %d threads\n", |
| 438 | tcount); |
| 439 | sema_init(&prestart_sem, 1 - tcount); |
| 440 | tdata = vzalloc(tcount * sizeof(struct thread_data)); |
| 441 | if (!tdata) |
| 442 | return -ENOMEM; |
| 443 | objs = vzalloc(tcount * entries * sizeof(struct test_obj)); |
| 444 | if (!objs) { |
| 445 | vfree(tdata); |
| 446 | return -ENOMEM; |
| 447 | } |
| 448 | |
| 449 | test_rht_params.max_size = max_size ? : |
| 450 | roundup_pow_of_two(tcount * entries); |
| 451 | err = rhashtable_init(&ht, &test_rht_params); |
| 452 | if (err < 0) { |
| 453 | pr_warn("Test failed: Unable to initialize hashtable: %d\n", |
| 454 | err); |
| 455 | vfree(tdata); |
| 456 | vfree(objs); |
| 457 | return -EINVAL; |
| 458 | } |
| 459 | for (i = 0; i < tcount; i++) { |
| 460 | tdata[i].id = i; |
| 461 | tdata[i].entries = entries; |
| 462 | tdata[i].objs = objs + i * entries; |
| 463 | tdata[i].task = kthread_run(threadfunc, &tdata[i], |
| 464 | "rhashtable_thrad[%d]", i); |
| 465 | if (IS_ERR(tdata[i].task)) |
| 466 | pr_err(" kthread_run failed for thread %d\n", i); |
| 467 | else |
| 468 | started_threads++; |
| 469 | } |
| 470 | if (down_interruptible(&prestart_sem)) |
| 471 | pr_err(" down interruptible failed\n"); |
| 472 | for (i = 0; i < tcount; i++) |
| 473 | up(&startup_sem); |
| 474 | for (i = 0; i < tcount; i++) { |
| 475 | if (IS_ERR(tdata[i].task)) |
| 476 | continue; |
| 477 | if ((err = kthread_stop(tdata[i].task))) { |
| 478 | pr_warn("Test failed: thread %d returned: %d\n", |
| 479 | i, err); |
| 480 | failed_threads++; |
| 481 | } |
| 482 | } |
| 483 | pr_info("Started %d threads, %d failed\n", |
| 484 | started_threads, failed_threads); |
| 485 | rhashtable_destroy(&ht); |
| 486 | vfree(tdata); |
| 487 | vfree(objs); |
| 488 | return 0; |
| 489 | } |
| 490 | |
| 491 | static void __exit test_rht_exit(void) |
| 492 | { |
| 493 | } |
| 494 | |
| 495 | module_init(test_rht_init); |
| 496 | module_exit(test_rht_exit); |
| 497 | |
| 498 | MODULE_LICENSE("GPL v2"); |