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7e1e7763 TG |
1 | /* |
2 | * Resizable, Scalable, Concurrent Hash Table | |
3 | * | |
4 | * Copyright (c) 2014 Thomas Graf <tgraf@suug.ch> | |
5 | * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net> | |
6 | * | |
7 | * Based on the following paper: | |
8 | * https://www.usenix.org/legacy/event/atc11/tech/final_files/Triplett.pdf | |
9 | * | |
10 | * Code partially derived from nft_hash | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | */ | |
16 | ||
17 | #include <linux/kernel.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/log2.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/vmalloc.h> | |
22 | #include <linux/mm.h> | |
87545899 | 23 | #include <linux/jhash.h> |
7e1e7763 TG |
24 | #include <linux/random.h> |
25 | #include <linux/rhashtable.h> | |
7e1e7763 TG |
26 | |
27 | #define HASH_DEFAULT_SIZE 64UL | |
28 | #define HASH_MIN_SIZE 4UL | |
97defe1e TG |
29 | #define BUCKET_LOCKS_PER_CPU 128UL |
30 | ||
f89bd6f8 TG |
31 | /* Base bits plus 1 bit for nulls marker */ |
32 | #define HASH_RESERVED_SPACE (RHT_BASE_BITS + 1) | |
33 | ||
97defe1e TG |
34 | enum { |
35 | RHT_LOCK_NORMAL, | |
36 | RHT_LOCK_NESTED, | |
37 | RHT_LOCK_NESTED2, | |
38 | }; | |
39 | ||
40 | /* The bucket lock is selected based on the hash and protects mutations | |
41 | * on a group of hash buckets. | |
42 | * | |
43 | * IMPORTANT: When holding the bucket lock of both the old and new table | |
44 | * during expansions and shrinking, the old bucket lock must always be | |
45 | * acquired first. | |
46 | */ | |
47 | static spinlock_t *bucket_lock(const struct bucket_table *tbl, u32 hash) | |
48 | { | |
49 | return &tbl->locks[hash & tbl->locks_mask]; | |
50 | } | |
7e1e7763 TG |
51 | |
52 | #define ASSERT_RHT_MUTEX(HT) BUG_ON(!lockdep_rht_mutex_is_held(HT)) | |
97defe1e TG |
53 | #define ASSERT_BUCKET_LOCK(TBL, HASH) \ |
54 | BUG_ON(!lockdep_rht_bucket_is_held(TBL, HASH)) | |
7e1e7763 TG |
55 | |
56 | #ifdef CONFIG_PROVE_LOCKING | |
97defe1e | 57 | int lockdep_rht_mutex_is_held(struct rhashtable *ht) |
7e1e7763 | 58 | { |
97defe1e | 59 | return (debug_locks) ? lockdep_is_held(&ht->mutex) : 1; |
7e1e7763 TG |
60 | } |
61 | EXPORT_SYMBOL_GPL(lockdep_rht_mutex_is_held); | |
88d6ed15 TG |
62 | |
63 | int lockdep_rht_bucket_is_held(const struct bucket_table *tbl, u32 hash) | |
64 | { | |
97defe1e TG |
65 | spinlock_t *lock = bucket_lock(tbl, hash); |
66 | ||
67 | return (debug_locks) ? lockdep_is_held(lock) : 1; | |
88d6ed15 TG |
68 | } |
69 | EXPORT_SYMBOL_GPL(lockdep_rht_bucket_is_held); | |
7e1e7763 TG |
70 | #endif |
71 | ||
c91eee56 | 72 | static void *rht_obj(const struct rhashtable *ht, const struct rhash_head *he) |
7e1e7763 TG |
73 | { |
74 | return (void *) he - ht->p.head_offset; | |
75 | } | |
7e1e7763 | 76 | |
8d24c0b4 | 77 | static u32 rht_bucket_index(const struct bucket_table *tbl, u32 hash) |
7e1e7763 | 78 | { |
8d24c0b4 | 79 | return hash & (tbl->size - 1); |
7e1e7763 | 80 | } |
7e1e7763 | 81 | |
8d24c0b4 | 82 | static u32 obj_raw_hashfn(const struct rhashtable *ht, const void *ptr) |
7e1e7763 | 83 | { |
8d24c0b4 | 84 | u32 hash; |
7e1e7763 | 85 | |
8d24c0b4 TG |
86 | if (unlikely(!ht->p.key_len)) |
87 | hash = ht->p.obj_hashfn(ptr, ht->p.hash_rnd); | |
88 | else | |
89 | hash = ht->p.hashfn(ptr + ht->p.key_offset, ht->p.key_len, | |
90 | ht->p.hash_rnd); | |
7e1e7763 | 91 | |
f89bd6f8 | 92 | return hash >> HASH_RESERVED_SPACE; |
7e1e7763 TG |
93 | } |
94 | ||
97defe1e | 95 | static u32 key_hashfn(struct rhashtable *ht, const void *key, u32 len) |
7e1e7763 TG |
96 | { |
97 | struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); | |
8d24c0b4 TG |
98 | u32 hash; |
99 | ||
100 | hash = ht->p.hashfn(key, len, ht->p.hash_rnd); | |
f89bd6f8 | 101 | hash >>= HASH_RESERVED_SPACE; |
7e1e7763 | 102 | |
8d24c0b4 | 103 | return rht_bucket_index(tbl, hash); |
7e1e7763 | 104 | } |
7e1e7763 TG |
105 | |
106 | static u32 head_hashfn(const struct rhashtable *ht, | |
8d24c0b4 TG |
107 | const struct bucket_table *tbl, |
108 | const struct rhash_head *he) | |
7e1e7763 | 109 | { |
8d24c0b4 | 110 | return rht_bucket_index(tbl, obj_raw_hashfn(ht, rht_obj(ht, he))); |
7e1e7763 TG |
111 | } |
112 | ||
b8e1943e TG |
113 | static struct rhash_head __rcu **bucket_tail(struct bucket_table *tbl, u32 n) |
114 | { | |
115 | struct rhash_head __rcu **pprev; | |
116 | ||
117 | for (pprev = &tbl->buckets[n]; | |
f89bd6f8 | 118 | !rht_is_a_nulls(rht_dereference_bucket(*pprev, tbl, n)); |
b8e1943e TG |
119 | pprev = &rht_dereference_bucket(*pprev, tbl, n)->next) |
120 | ; | |
121 | ||
122 | return pprev; | |
123 | } | |
124 | ||
97defe1e TG |
125 | static int alloc_bucket_locks(struct rhashtable *ht, struct bucket_table *tbl) |
126 | { | |
127 | unsigned int i, size; | |
128 | #if defined(CONFIG_PROVE_LOCKING) | |
129 | unsigned int nr_pcpus = 2; | |
130 | #else | |
131 | unsigned int nr_pcpus = num_possible_cpus(); | |
132 | #endif | |
133 | ||
134 | nr_pcpus = min_t(unsigned int, nr_pcpus, 32UL); | |
135 | size = roundup_pow_of_two(nr_pcpus * ht->p.locks_mul); | |
136 | ||
137 | /* Never allocate more than one lock per bucket */ | |
138 | size = min_t(unsigned int, size, tbl->size); | |
139 | ||
140 | if (sizeof(spinlock_t) != 0) { | |
141 | #ifdef CONFIG_NUMA | |
142 | if (size * sizeof(spinlock_t) > PAGE_SIZE) | |
143 | tbl->locks = vmalloc(size * sizeof(spinlock_t)); | |
144 | else | |
145 | #endif | |
146 | tbl->locks = kmalloc_array(size, sizeof(spinlock_t), | |
147 | GFP_KERNEL); | |
148 | if (!tbl->locks) | |
149 | return -ENOMEM; | |
150 | for (i = 0; i < size; i++) | |
151 | spin_lock_init(&tbl->locks[i]); | |
152 | } | |
153 | tbl->locks_mask = size - 1; | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | static void bucket_table_free(const struct bucket_table *tbl) | |
159 | { | |
160 | if (tbl) | |
161 | kvfree(tbl->locks); | |
162 | ||
163 | kvfree(tbl); | |
164 | } | |
165 | ||
166 | static struct bucket_table *bucket_table_alloc(struct rhashtable *ht, | |
167 | size_t nbuckets) | |
7e1e7763 TG |
168 | { |
169 | struct bucket_table *tbl; | |
170 | size_t size; | |
f89bd6f8 | 171 | int i; |
7e1e7763 TG |
172 | |
173 | size = sizeof(*tbl) + nbuckets * sizeof(tbl->buckets[0]); | |
6eba8224 | 174 | tbl = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); |
7e1e7763 TG |
175 | if (tbl == NULL) |
176 | tbl = vzalloc(size); | |
177 | ||
178 | if (tbl == NULL) | |
179 | return NULL; | |
180 | ||
181 | tbl->size = nbuckets; | |
182 | ||
97defe1e TG |
183 | if (alloc_bucket_locks(ht, tbl) < 0) { |
184 | bucket_table_free(tbl); | |
185 | return NULL; | |
186 | } | |
7e1e7763 | 187 | |
f89bd6f8 TG |
188 | for (i = 0; i < nbuckets; i++) |
189 | INIT_RHT_NULLS_HEAD(tbl->buckets[i], ht, i); | |
190 | ||
97defe1e | 191 | return tbl; |
7e1e7763 TG |
192 | } |
193 | ||
194 | /** | |
195 | * rht_grow_above_75 - returns true if nelems > 0.75 * table-size | |
196 | * @ht: hash table | |
197 | * @new_size: new table size | |
198 | */ | |
199 | bool rht_grow_above_75(const struct rhashtable *ht, size_t new_size) | |
200 | { | |
201 | /* Expand table when exceeding 75% load */ | |
97defe1e | 202 | return atomic_read(&ht->nelems) > (new_size / 4 * 3); |
7e1e7763 TG |
203 | } |
204 | EXPORT_SYMBOL_GPL(rht_grow_above_75); | |
205 | ||
206 | /** | |
207 | * rht_shrink_below_30 - returns true if nelems < 0.3 * table-size | |
208 | * @ht: hash table | |
209 | * @new_size: new table size | |
210 | */ | |
211 | bool rht_shrink_below_30(const struct rhashtable *ht, size_t new_size) | |
212 | { | |
213 | /* Shrink table beneath 30% load */ | |
97defe1e | 214 | return atomic_read(&ht->nelems) < (new_size * 3 / 10); |
7e1e7763 TG |
215 | } |
216 | EXPORT_SYMBOL_GPL(rht_shrink_below_30); | |
217 | ||
218 | static void hashtable_chain_unzip(const struct rhashtable *ht, | |
219 | const struct bucket_table *new_tbl, | |
97defe1e TG |
220 | struct bucket_table *old_tbl, |
221 | size_t old_hash) | |
7e1e7763 TG |
222 | { |
223 | struct rhash_head *he, *p, *next; | |
97defe1e TG |
224 | spinlock_t *new_bucket_lock, *new_bucket_lock2 = NULL; |
225 | unsigned int new_hash, new_hash2; | |
226 | ||
227 | ASSERT_BUCKET_LOCK(old_tbl, old_hash); | |
7e1e7763 TG |
228 | |
229 | /* Old bucket empty, no work needed. */ | |
97defe1e TG |
230 | p = rht_dereference_bucket(old_tbl->buckets[old_hash], old_tbl, |
231 | old_hash); | |
f89bd6f8 | 232 | if (rht_is_a_nulls(p)) |
7e1e7763 TG |
233 | return; |
234 | ||
97defe1e TG |
235 | new_hash = new_hash2 = head_hashfn(ht, new_tbl, p); |
236 | new_bucket_lock = bucket_lock(new_tbl, new_hash); | |
237 | ||
7e1e7763 TG |
238 | /* Advance the old bucket pointer one or more times until it |
239 | * reaches a node that doesn't hash to the same bucket as the | |
240 | * previous node p. Call the previous node p; | |
241 | */ | |
97defe1e TG |
242 | rht_for_each_continue(he, p->next, old_tbl, old_hash) { |
243 | new_hash2 = head_hashfn(ht, new_tbl, he); | |
244 | if (new_hash != new_hash2) | |
7e1e7763 TG |
245 | break; |
246 | p = he; | |
247 | } | |
97defe1e TG |
248 | rcu_assign_pointer(old_tbl->buckets[old_hash], p->next); |
249 | ||
250 | spin_lock_bh_nested(new_bucket_lock, RHT_LOCK_NESTED); | |
251 | ||
252 | /* If we have encountered an entry that maps to a different bucket in | |
253 | * the new table, lock down that bucket as well as we might cut off | |
254 | * the end of the chain. | |
255 | */ | |
256 | new_bucket_lock2 = bucket_lock(new_tbl, new_hash); | |
257 | if (new_bucket_lock != new_bucket_lock2) | |
258 | spin_lock_bh_nested(new_bucket_lock2, RHT_LOCK_NESTED2); | |
7e1e7763 TG |
259 | |
260 | /* Find the subsequent node which does hash to the same | |
261 | * bucket as node P, or NULL if no such node exists. | |
262 | */ | |
f89bd6f8 TG |
263 | INIT_RHT_NULLS_HEAD(next, ht, old_hash); |
264 | if (!rht_is_a_nulls(he)) { | |
97defe1e TG |
265 | rht_for_each_continue(he, he->next, old_tbl, old_hash) { |
266 | if (head_hashfn(ht, new_tbl, he) == new_hash) { | |
7e1e7763 TG |
267 | next = he; |
268 | break; | |
269 | } | |
270 | } | |
271 | } | |
272 | ||
273 | /* Set p's next pointer to that subsequent node pointer, | |
274 | * bypassing the nodes which do not hash to p's bucket | |
275 | */ | |
97defe1e TG |
276 | rcu_assign_pointer(p->next, next); |
277 | ||
278 | if (new_bucket_lock != new_bucket_lock2) | |
279 | spin_unlock_bh(new_bucket_lock2); | |
280 | spin_unlock_bh(new_bucket_lock); | |
281 | } | |
282 | ||
283 | static void link_old_to_new(struct bucket_table *new_tbl, | |
284 | unsigned int new_hash, struct rhash_head *entry) | |
285 | { | |
286 | spinlock_t *new_bucket_lock; | |
287 | ||
288 | new_bucket_lock = bucket_lock(new_tbl, new_hash); | |
289 | ||
290 | spin_lock_bh_nested(new_bucket_lock, RHT_LOCK_NESTED); | |
291 | rcu_assign_pointer(*bucket_tail(new_tbl, new_hash), entry); | |
292 | spin_unlock_bh(new_bucket_lock); | |
7e1e7763 TG |
293 | } |
294 | ||
295 | /** | |
296 | * rhashtable_expand - Expand hash table while allowing concurrent lookups | |
297 | * @ht: the hash table to expand | |
7e1e7763 TG |
298 | * |
299 | * A secondary bucket array is allocated and the hash entries are migrated | |
300 | * while keeping them on both lists until the end of the RCU grace period. | |
301 | * | |
302 | * This function may only be called in a context where it is safe to call | |
303 | * synchronize_rcu(), e.g. not within a rcu_read_lock() section. | |
304 | * | |
97defe1e TG |
305 | * The caller must ensure that no concurrent resizing occurs by holding |
306 | * ht->mutex. | |
307 | * | |
308 | * It is valid to have concurrent insertions and deletions protected by per | |
309 | * bucket locks or concurrent RCU protected lookups and traversals. | |
7e1e7763 | 310 | */ |
6eba8224 | 311 | int rhashtable_expand(struct rhashtable *ht) |
7e1e7763 TG |
312 | { |
313 | struct bucket_table *new_tbl, *old_tbl = rht_dereference(ht->tbl, ht); | |
314 | struct rhash_head *he; | |
97defe1e TG |
315 | spinlock_t *old_bucket_lock; |
316 | unsigned int new_hash, old_hash; | |
317 | bool complete = false; | |
7e1e7763 TG |
318 | |
319 | ASSERT_RHT_MUTEX(ht); | |
320 | ||
321 | if (ht->p.max_shift && ht->shift >= ht->p.max_shift) | |
322 | return 0; | |
323 | ||
97defe1e | 324 | new_tbl = bucket_table_alloc(ht, old_tbl->size * 2); |
7e1e7763 TG |
325 | if (new_tbl == NULL) |
326 | return -ENOMEM; | |
327 | ||
328 | ht->shift++; | |
329 | ||
97defe1e TG |
330 | /* Make insertions go into the new, empty table right away. Deletions |
331 | * and lookups will be attempted in both tables until we synchronize. | |
332 | * The synchronize_rcu() guarantees for the new table to be picked up | |
333 | * so no new additions go into the old table while we relink. | |
334 | */ | |
335 | rcu_assign_pointer(ht->future_tbl, new_tbl); | |
336 | synchronize_rcu(); | |
337 | ||
338 | /* For each new bucket, search the corresponding old bucket for the | |
339 | * first entry that hashes to the new bucket, and link the end of | |
340 | * newly formed bucket chain (containing entries added to future | |
341 | * table) to that entry. Since all the entries which will end up in | |
342 | * the new bucket appear in the same old bucket, this constructs an | |
343 | * entirely valid new hash table, but with multiple buckets | |
344 | * "zipped" together into a single imprecise chain. | |
7e1e7763 | 345 | */ |
97defe1e TG |
346 | for (new_hash = 0; new_hash < new_tbl->size; new_hash++) { |
347 | old_hash = rht_bucket_index(old_tbl, new_hash); | |
348 | old_bucket_lock = bucket_lock(old_tbl, old_hash); | |
349 | ||
350 | spin_lock_bh(old_bucket_lock); | |
351 | rht_for_each(he, old_tbl, old_hash) { | |
352 | if (head_hashfn(ht, new_tbl, he) == new_hash) { | |
353 | link_old_to_new(new_tbl, new_hash, he); | |
7e1e7763 TG |
354 | break; |
355 | } | |
356 | } | |
97defe1e | 357 | spin_unlock_bh(old_bucket_lock); |
7e1e7763 TG |
358 | } |
359 | ||
360 | /* Publish the new table pointer. Lookups may now traverse | |
0c828f2f HX |
361 | * the new table, but they will not benefit from any |
362 | * additional efficiency until later steps unzip the buckets. | |
7e1e7763 TG |
363 | */ |
364 | rcu_assign_pointer(ht->tbl, new_tbl); | |
365 | ||
366 | /* Unzip interleaved hash chains */ | |
97defe1e | 367 | while (!complete && !ht->being_destroyed) { |
7e1e7763 TG |
368 | /* Wait for readers. All new readers will see the new |
369 | * table, and thus no references to the old table will | |
370 | * remain. | |
371 | */ | |
372 | synchronize_rcu(); | |
373 | ||
374 | /* For each bucket in the old table (each of which | |
375 | * contains items from multiple buckets of the new | |
376 | * table): ... | |
377 | */ | |
378 | complete = true; | |
97defe1e | 379 | for (old_hash = 0; old_hash < old_tbl->size; old_hash++) { |
f89bd6f8 TG |
380 | struct rhash_head *head; |
381 | ||
97defe1e TG |
382 | old_bucket_lock = bucket_lock(old_tbl, old_hash); |
383 | spin_lock_bh(old_bucket_lock); | |
384 | ||
385 | hashtable_chain_unzip(ht, new_tbl, old_tbl, old_hash); | |
f89bd6f8 TG |
386 | head = rht_dereference_bucket(old_tbl->buckets[old_hash], |
387 | old_tbl, old_hash); | |
388 | if (!rht_is_a_nulls(head)) | |
7e1e7763 | 389 | complete = false; |
97defe1e TG |
390 | |
391 | spin_unlock_bh(old_bucket_lock); | |
7e1e7763 | 392 | } |
97defe1e | 393 | } |
7e1e7763 TG |
394 | |
395 | bucket_table_free(old_tbl); | |
396 | return 0; | |
397 | } | |
398 | EXPORT_SYMBOL_GPL(rhashtable_expand); | |
399 | ||
400 | /** | |
401 | * rhashtable_shrink - Shrink hash table while allowing concurrent lookups | |
402 | * @ht: the hash table to shrink | |
7e1e7763 TG |
403 | * |
404 | * This function may only be called in a context where it is safe to call | |
405 | * synchronize_rcu(), e.g. not within a rcu_read_lock() section. | |
406 | * | |
97defe1e TG |
407 | * The caller must ensure that no concurrent resizing occurs by holding |
408 | * ht->mutex. | |
409 | * | |
7e1e7763 TG |
410 | * The caller must ensure that no concurrent table mutations take place. |
411 | * It is however valid to have concurrent lookups if they are RCU protected. | |
97defe1e TG |
412 | * |
413 | * It is valid to have concurrent insertions and deletions protected by per | |
414 | * bucket locks or concurrent RCU protected lookups and traversals. | |
7e1e7763 | 415 | */ |
6eba8224 | 416 | int rhashtable_shrink(struct rhashtable *ht) |
7e1e7763 | 417 | { |
97defe1e TG |
418 | struct bucket_table *new_tbl, *tbl = rht_dereference(ht->tbl, ht); |
419 | spinlock_t *new_bucket_lock, *old_bucket_lock1, *old_bucket_lock2; | |
420 | unsigned int new_hash; | |
7e1e7763 TG |
421 | |
422 | ASSERT_RHT_MUTEX(ht); | |
423 | ||
94000176 | 424 | if (ht->shift <= ht->p.min_shift) |
7e1e7763 TG |
425 | return 0; |
426 | ||
97defe1e TG |
427 | new_tbl = bucket_table_alloc(ht, tbl->size / 2); |
428 | if (new_tbl == NULL) | |
7e1e7763 TG |
429 | return -ENOMEM; |
430 | ||
97defe1e TG |
431 | rcu_assign_pointer(ht->future_tbl, new_tbl); |
432 | synchronize_rcu(); | |
7e1e7763 | 433 | |
97defe1e TG |
434 | /* Link the first entry in the old bucket to the end of the |
435 | * bucket in the new table. As entries are concurrently being | |
436 | * added to the new table, lock down the new bucket. As we | |
437 | * always divide the size in half when shrinking, each bucket | |
438 | * in the new table maps to exactly two buckets in the old | |
439 | * table. | |
440 | * | |
441 | * As removals can occur concurrently on the old table, we need | |
442 | * to lock down both matching buckets in the old table. | |
7e1e7763 | 443 | */ |
97defe1e TG |
444 | for (new_hash = 0; new_hash < new_tbl->size; new_hash++) { |
445 | old_bucket_lock1 = bucket_lock(tbl, new_hash); | |
446 | old_bucket_lock2 = bucket_lock(tbl, new_hash + new_tbl->size); | |
447 | new_bucket_lock = bucket_lock(new_tbl, new_hash); | |
448 | ||
449 | spin_lock_bh(old_bucket_lock1); | |
450 | spin_lock_bh_nested(old_bucket_lock2, RHT_LOCK_NESTED); | |
451 | spin_lock_bh_nested(new_bucket_lock, RHT_LOCK_NESTED2); | |
452 | ||
453 | rcu_assign_pointer(*bucket_tail(new_tbl, new_hash), | |
454 | tbl->buckets[new_hash]); | |
455 | rcu_assign_pointer(*bucket_tail(new_tbl, new_hash), | |
456 | tbl->buckets[new_hash + new_tbl->size]); | |
457 | ||
458 | spin_unlock_bh(new_bucket_lock); | |
459 | spin_unlock_bh(old_bucket_lock2); | |
460 | spin_unlock_bh(old_bucket_lock1); | |
7e1e7763 TG |
461 | } |
462 | ||
463 | /* Publish the new, valid hash table */ | |
97defe1e TG |
464 | rcu_assign_pointer(ht->tbl, new_tbl); |
465 | ht->shift--; | |
7e1e7763 TG |
466 | |
467 | /* Wait for readers. No new readers will have references to the | |
468 | * old hash table. | |
469 | */ | |
470 | synchronize_rcu(); | |
471 | ||
472 | bucket_table_free(tbl); | |
473 | ||
474 | return 0; | |
475 | } | |
476 | EXPORT_SYMBOL_GPL(rhashtable_shrink); | |
477 | ||
97defe1e TG |
478 | static void rht_deferred_worker(struct work_struct *work) |
479 | { | |
480 | struct rhashtable *ht; | |
481 | struct bucket_table *tbl; | |
482 | ||
483 | ht = container_of(work, struct rhashtable, run_work.work); | |
484 | mutex_lock(&ht->mutex); | |
485 | tbl = rht_dereference(ht->tbl, ht); | |
486 | ||
487 | if (ht->p.grow_decision && ht->p.grow_decision(ht, tbl->size)) | |
488 | rhashtable_expand(ht); | |
489 | else if (ht->p.shrink_decision && ht->p.shrink_decision(ht, tbl->size)) | |
490 | rhashtable_shrink(ht); | |
491 | ||
492 | mutex_unlock(&ht->mutex); | |
493 | } | |
494 | ||
54c5b7d3 YX |
495 | static void rhashtable_wakeup_worker(struct rhashtable *ht) |
496 | { | |
497 | struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); | |
498 | struct bucket_table *new_tbl = rht_dereference_rcu(ht->future_tbl, ht); | |
499 | size_t size = tbl->size; | |
500 | ||
501 | /* Only adjust the table if no resizing is currently in progress. */ | |
502 | if (tbl == new_tbl && | |
503 | ((ht->p.grow_decision && ht->p.grow_decision(ht, size)) || | |
504 | (ht->p.shrink_decision && ht->p.shrink_decision(ht, size)))) | |
505 | schedule_delayed_work(&ht->run_work, 0); | |
506 | } | |
507 | ||
7e1e7763 TG |
508 | /** |
509 | * rhashtable_insert - insert object into hash hash table | |
510 | * @ht: hash table | |
511 | * @obj: pointer to hash head inside object | |
7e1e7763 | 512 | * |
97defe1e TG |
513 | * Will take a per bucket spinlock to protect against mutual mutations |
514 | * on the same bucket. Multiple insertions may occur in parallel unless | |
515 | * they map to the same bucket lock. | |
7e1e7763 | 516 | * |
97defe1e TG |
517 | * It is safe to call this function from atomic context. |
518 | * | |
519 | * Will trigger an automatic deferred table resizing if the size grows | |
520 | * beyond the watermark indicated by grow_decision() which can be passed | |
521 | * to rhashtable_init(). | |
7e1e7763 | 522 | */ |
6eba8224 | 523 | void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj) |
7e1e7763 | 524 | { |
97defe1e | 525 | struct bucket_table *tbl; |
f89bd6f8 | 526 | struct rhash_head *head; |
97defe1e TG |
527 | spinlock_t *lock; |
528 | unsigned hash; | |
7e1e7763 | 529 | |
97defe1e | 530 | rcu_read_lock(); |
7e1e7763 | 531 | |
97defe1e | 532 | tbl = rht_dereference_rcu(ht->future_tbl, ht); |
8d24c0b4 | 533 | hash = head_hashfn(ht, tbl, obj); |
97defe1e TG |
534 | lock = bucket_lock(tbl, hash); |
535 | ||
536 | spin_lock_bh(lock); | |
f89bd6f8 TG |
537 | head = rht_dereference_bucket(tbl->buckets[hash], tbl, hash); |
538 | if (rht_is_a_nulls(head)) | |
539 | INIT_RHT_NULLS_HEAD(obj->next, ht, hash); | |
540 | else | |
541 | RCU_INIT_POINTER(obj->next, head); | |
542 | ||
7e1e7763 | 543 | rcu_assign_pointer(tbl->buckets[hash], obj); |
97defe1e | 544 | spin_unlock_bh(lock); |
7e1e7763 | 545 | |
97defe1e TG |
546 | atomic_inc(&ht->nelems); |
547 | ||
54c5b7d3 | 548 | rhashtable_wakeup_worker(ht); |
97defe1e TG |
549 | |
550 | rcu_read_unlock(); | |
7e1e7763 TG |
551 | } |
552 | EXPORT_SYMBOL_GPL(rhashtable_insert); | |
553 | ||
7e1e7763 TG |
554 | /** |
555 | * rhashtable_remove - remove object from hash table | |
556 | * @ht: hash table | |
557 | * @obj: pointer to hash head inside object | |
7e1e7763 TG |
558 | * |
559 | * Since the hash chain is single linked, the removal operation needs to | |
560 | * walk the bucket chain upon removal. The removal operation is thus | |
561 | * considerable slow if the hash table is not correctly sized. | |
562 | * | |
563 | * Will automatically shrink the table via rhashtable_expand() if the the | |
564 | * shrink_decision function specified at rhashtable_init() returns true. | |
565 | * | |
566 | * The caller must ensure that no concurrent table mutations occur. It is | |
567 | * however valid to have concurrent lookups if they are RCU protected. | |
568 | */ | |
6eba8224 | 569 | bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj) |
7e1e7763 | 570 | { |
97defe1e | 571 | struct bucket_table *tbl; |
7e1e7763 TG |
572 | struct rhash_head __rcu **pprev; |
573 | struct rhash_head *he; | |
97defe1e TG |
574 | spinlock_t *lock; |
575 | unsigned int hash; | |
7e1e7763 | 576 | |
97defe1e TG |
577 | rcu_read_lock(); |
578 | tbl = rht_dereference_rcu(ht->tbl, ht); | |
579 | hash = head_hashfn(ht, tbl, obj); | |
7e1e7763 | 580 | |
97defe1e TG |
581 | lock = bucket_lock(tbl, hash); |
582 | spin_lock_bh(lock); | |
7e1e7763 | 583 | |
97defe1e TG |
584 | restart: |
585 | pprev = &tbl->buckets[hash]; | |
586 | rht_for_each(he, tbl, hash) { | |
7e1e7763 TG |
587 | if (he != obj) { |
588 | pprev = &he->next; | |
589 | continue; | |
590 | } | |
591 | ||
97defe1e TG |
592 | rcu_assign_pointer(*pprev, obj->next); |
593 | atomic_dec(&ht->nelems); | |
897362e4 | 594 | |
97defe1e TG |
595 | spin_unlock_bh(lock); |
596 | ||
54c5b7d3 | 597 | rhashtable_wakeup_worker(ht); |
97defe1e TG |
598 | |
599 | rcu_read_unlock(); | |
897362e4 | 600 | |
7e1e7763 TG |
601 | return true; |
602 | } | |
603 | ||
97defe1e TG |
604 | if (tbl != rht_dereference_rcu(ht->tbl, ht)) { |
605 | spin_unlock_bh(lock); | |
606 | ||
607 | tbl = rht_dereference_rcu(ht->tbl, ht); | |
608 | hash = head_hashfn(ht, tbl, obj); | |
609 | ||
610 | lock = bucket_lock(tbl, hash); | |
611 | spin_lock_bh(lock); | |
612 | goto restart; | |
613 | } | |
614 | ||
615 | spin_unlock_bh(lock); | |
616 | rcu_read_unlock(); | |
617 | ||
7e1e7763 TG |
618 | return false; |
619 | } | |
620 | EXPORT_SYMBOL_GPL(rhashtable_remove); | |
621 | ||
efb975a6 YX |
622 | struct rhashtable_compare_arg { |
623 | struct rhashtable *ht; | |
624 | const void *key; | |
625 | }; | |
626 | ||
627 | static bool rhashtable_compare(void *ptr, void *arg) | |
628 | { | |
629 | struct rhashtable_compare_arg *x = arg; | |
630 | struct rhashtable *ht = x->ht; | |
631 | ||
632 | return !memcmp(ptr + ht->p.key_offset, x->key, ht->p.key_len); | |
633 | } | |
634 | ||
7e1e7763 TG |
635 | /** |
636 | * rhashtable_lookup - lookup key in hash table | |
637 | * @ht: hash table | |
638 | * @key: pointer to key | |
639 | * | |
640 | * Computes the hash value for the key and traverses the bucket chain looking | |
641 | * for a entry with an identical key. The first matching entry is returned. | |
642 | * | |
643 | * This lookup function may only be used for fixed key hash table (key_len | |
644 | * paramter set). It will BUG() if used inappropriately. | |
645 | * | |
97defe1e | 646 | * Lookups may occur in parallel with hashtable mutations and resizing. |
7e1e7763 | 647 | */ |
97defe1e | 648 | void *rhashtable_lookup(struct rhashtable *ht, const void *key) |
7e1e7763 | 649 | { |
efb975a6 YX |
650 | struct rhashtable_compare_arg arg = { |
651 | .ht = ht, | |
652 | .key = key, | |
653 | }; | |
7e1e7763 TG |
654 | |
655 | BUG_ON(!ht->p.key_len); | |
656 | ||
efb975a6 | 657 | return rhashtable_lookup_compare(ht, key, &rhashtable_compare, &arg); |
7e1e7763 TG |
658 | } |
659 | EXPORT_SYMBOL_GPL(rhashtable_lookup); | |
660 | ||
661 | /** | |
662 | * rhashtable_lookup_compare - search hash table with compare function | |
663 | * @ht: hash table | |
8d24c0b4 | 664 | * @key: the pointer to the key |
7e1e7763 TG |
665 | * @compare: compare function, must return true on match |
666 | * @arg: argument passed on to compare function | |
667 | * | |
668 | * Traverses the bucket chain behind the provided hash value and calls the | |
669 | * specified compare function for each entry. | |
670 | * | |
97defe1e | 671 | * Lookups may occur in parallel with hashtable mutations and resizing. |
7e1e7763 TG |
672 | * |
673 | * Returns the first entry on which the compare function returned true. | |
674 | */ | |
97defe1e | 675 | void *rhashtable_lookup_compare(struct rhashtable *ht, const void *key, |
7e1e7763 TG |
676 | bool (*compare)(void *, void *), void *arg) |
677 | { | |
97defe1e | 678 | const struct bucket_table *tbl, *old_tbl; |
7e1e7763 | 679 | struct rhash_head *he; |
8d24c0b4 | 680 | u32 hash; |
7e1e7763 | 681 | |
97defe1e TG |
682 | rcu_read_lock(); |
683 | ||
684 | old_tbl = rht_dereference_rcu(ht->tbl, ht); | |
685 | tbl = rht_dereference_rcu(ht->future_tbl, ht); | |
8d24c0b4 | 686 | hash = key_hashfn(ht, key, ht->p.key_len); |
97defe1e TG |
687 | restart: |
688 | rht_for_each_rcu(he, tbl, rht_bucket_index(tbl, hash)) { | |
7e1e7763 TG |
689 | if (!compare(rht_obj(ht, he), arg)) |
690 | continue; | |
97defe1e | 691 | rcu_read_unlock(); |
a4b18cda | 692 | return rht_obj(ht, he); |
7e1e7763 TG |
693 | } |
694 | ||
97defe1e TG |
695 | if (unlikely(tbl != old_tbl)) { |
696 | tbl = old_tbl; | |
697 | goto restart; | |
698 | } | |
699 | rcu_read_unlock(); | |
700 | ||
7e1e7763 TG |
701 | return NULL; |
702 | } | |
703 | EXPORT_SYMBOL_GPL(rhashtable_lookup_compare); | |
704 | ||
94000176 | 705 | static size_t rounded_hashtable_size(struct rhashtable_params *params) |
7e1e7763 | 706 | { |
94000176 YX |
707 | return max(roundup_pow_of_two(params->nelem_hint * 4 / 3), |
708 | 1UL << params->min_shift); | |
7e1e7763 TG |
709 | } |
710 | ||
711 | /** | |
712 | * rhashtable_init - initialize a new hash table | |
713 | * @ht: hash table to be initialized | |
714 | * @params: configuration parameters | |
715 | * | |
716 | * Initializes a new hash table based on the provided configuration | |
717 | * parameters. A table can be configured either with a variable or | |
718 | * fixed length key: | |
719 | * | |
720 | * Configuration Example 1: Fixed length keys | |
721 | * struct test_obj { | |
722 | * int key; | |
723 | * void * my_member; | |
724 | * struct rhash_head node; | |
725 | * }; | |
726 | * | |
727 | * struct rhashtable_params params = { | |
728 | * .head_offset = offsetof(struct test_obj, node), | |
729 | * .key_offset = offsetof(struct test_obj, key), | |
730 | * .key_len = sizeof(int), | |
87545899 | 731 | * .hashfn = jhash, |
f89bd6f8 | 732 | * .nulls_base = (1U << RHT_BASE_SHIFT), |
7e1e7763 TG |
733 | * }; |
734 | * | |
735 | * Configuration Example 2: Variable length keys | |
736 | * struct test_obj { | |
737 | * [...] | |
738 | * struct rhash_head node; | |
739 | * }; | |
740 | * | |
741 | * u32 my_hash_fn(const void *data, u32 seed) | |
742 | * { | |
743 | * struct test_obj *obj = data; | |
744 | * | |
745 | * return [... hash ...]; | |
746 | * } | |
747 | * | |
748 | * struct rhashtable_params params = { | |
749 | * .head_offset = offsetof(struct test_obj, node), | |
87545899 | 750 | * .hashfn = jhash, |
7e1e7763 | 751 | * .obj_hashfn = my_hash_fn, |
7e1e7763 TG |
752 | * }; |
753 | */ | |
754 | int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params) | |
755 | { | |
756 | struct bucket_table *tbl; | |
757 | size_t size; | |
758 | ||
759 | size = HASH_DEFAULT_SIZE; | |
760 | ||
761 | if ((params->key_len && !params->hashfn) || | |
762 | (!params->key_len && !params->obj_hashfn)) | |
763 | return -EINVAL; | |
764 | ||
f89bd6f8 TG |
765 | if (params->nulls_base && params->nulls_base < (1U << RHT_BASE_SHIFT)) |
766 | return -EINVAL; | |
767 | ||
94000176 YX |
768 | params->min_shift = max_t(size_t, params->min_shift, |
769 | ilog2(HASH_MIN_SIZE)); | |
770 | ||
7e1e7763 | 771 | if (params->nelem_hint) |
94000176 | 772 | size = rounded_hashtable_size(params); |
7e1e7763 | 773 | |
97defe1e TG |
774 | memset(ht, 0, sizeof(*ht)); |
775 | mutex_init(&ht->mutex); | |
776 | memcpy(&ht->p, params, sizeof(*params)); | |
777 | ||
778 | if (params->locks_mul) | |
779 | ht->p.locks_mul = roundup_pow_of_two(params->locks_mul); | |
780 | else | |
781 | ht->p.locks_mul = BUCKET_LOCKS_PER_CPU; | |
782 | ||
783 | tbl = bucket_table_alloc(ht, size); | |
7e1e7763 TG |
784 | if (tbl == NULL) |
785 | return -ENOMEM; | |
786 | ||
7e1e7763 | 787 | ht->shift = ilog2(tbl->size); |
7e1e7763 | 788 | RCU_INIT_POINTER(ht->tbl, tbl); |
97defe1e | 789 | RCU_INIT_POINTER(ht->future_tbl, tbl); |
7e1e7763 TG |
790 | |
791 | if (!ht->p.hash_rnd) | |
792 | get_random_bytes(&ht->p.hash_rnd, sizeof(ht->p.hash_rnd)); | |
793 | ||
97defe1e TG |
794 | if (ht->p.grow_decision || ht->p.shrink_decision) |
795 | INIT_DEFERRABLE_WORK(&ht->run_work, rht_deferred_worker); | |
796 | ||
7e1e7763 TG |
797 | return 0; |
798 | } | |
799 | EXPORT_SYMBOL_GPL(rhashtable_init); | |
800 | ||
801 | /** | |
802 | * rhashtable_destroy - destroy hash table | |
803 | * @ht: the hash table to destroy | |
804 | * | |
ae82ddcf PNA |
805 | * Frees the bucket array. This function is not rcu safe, therefore the caller |
806 | * has to make sure that no resizing may happen by unpublishing the hashtable | |
807 | * and waiting for the quiescent cycle before releasing the bucket array. | |
7e1e7763 | 808 | */ |
97defe1e | 809 | void rhashtable_destroy(struct rhashtable *ht) |
7e1e7763 | 810 | { |
97defe1e TG |
811 | ht->being_destroyed = true; |
812 | ||
813 | mutex_lock(&ht->mutex); | |
814 | ||
815 | cancel_delayed_work(&ht->run_work); | |
816 | bucket_table_free(rht_dereference(ht->tbl, ht)); | |
817 | ||
818 | mutex_unlock(&ht->mutex); | |
7e1e7763 TG |
819 | } |
820 | EXPORT_SYMBOL_GPL(rhashtable_destroy); | |
821 | ||
822 | /************************************************************************** | |
823 | * Self Test | |
824 | **************************************************************************/ | |
825 | ||
826 | #ifdef CONFIG_TEST_RHASHTABLE | |
827 | ||
828 | #define TEST_HT_SIZE 8 | |
829 | #define TEST_ENTRIES 2048 | |
830 | #define TEST_PTR ((void *) 0xdeadbeef) | |
831 | #define TEST_NEXPANDS 4 | |
832 | ||
7e1e7763 TG |
833 | struct test_obj { |
834 | void *ptr; | |
835 | int value; | |
836 | struct rhash_head node; | |
837 | }; | |
838 | ||
839 | static int __init test_rht_lookup(struct rhashtable *ht) | |
840 | { | |
841 | unsigned int i; | |
842 | ||
843 | for (i = 0; i < TEST_ENTRIES * 2; i++) { | |
844 | struct test_obj *obj; | |
845 | bool expected = !(i % 2); | |
846 | u32 key = i; | |
847 | ||
848 | obj = rhashtable_lookup(ht, &key); | |
849 | ||
850 | if (expected && !obj) { | |
851 | pr_warn("Test failed: Could not find key %u\n", key); | |
852 | return -ENOENT; | |
853 | } else if (!expected && obj) { | |
854 | pr_warn("Test failed: Unexpected entry found for key %u\n", | |
855 | key); | |
856 | return -EEXIST; | |
857 | } else if (expected && obj) { | |
858 | if (obj->ptr != TEST_PTR || obj->value != i) { | |
859 | pr_warn("Test failed: Lookup value mismatch %p!=%p, %u!=%u\n", | |
860 | obj->ptr, TEST_PTR, obj->value, i); | |
861 | return -EINVAL; | |
862 | } | |
863 | } | |
864 | } | |
865 | ||
866 | return 0; | |
867 | } | |
868 | ||
3e7b2ec4 | 869 | static void test_bucket_stats(struct rhashtable *ht, bool quiet) |
7e1e7763 | 870 | { |
3e7b2ec4 | 871 | unsigned int cnt, rcu_cnt, i, total = 0; |
88d6ed15 | 872 | struct rhash_head *pos; |
7e1e7763 | 873 | struct test_obj *obj; |
3e7b2ec4 | 874 | struct bucket_table *tbl; |
7e1e7763 | 875 | |
3e7b2ec4 | 876 | tbl = rht_dereference_rcu(ht->tbl, ht); |
7e1e7763 | 877 | for (i = 0; i < tbl->size; i++) { |
3e7b2ec4 | 878 | rcu_cnt = cnt = 0; |
7e1e7763 TG |
879 | |
880 | if (!quiet) | |
881 | pr_info(" [%#4x/%zu]", i, tbl->size); | |
882 | ||
88d6ed15 | 883 | rht_for_each_entry_rcu(obj, pos, tbl, i, node) { |
7e1e7763 TG |
884 | cnt++; |
885 | total++; | |
886 | if (!quiet) | |
887 | pr_cont(" [%p],", obj); | |
888 | } | |
889 | ||
88d6ed15 | 890 | rht_for_each_entry_rcu(obj, pos, tbl, i, node) |
3e7b2ec4 TG |
891 | rcu_cnt++; |
892 | ||
893 | if (rcu_cnt != cnt) | |
894 | pr_warn("Test failed: Chain count mismach %d != %d", | |
895 | cnt, rcu_cnt); | |
896 | ||
7e1e7763 TG |
897 | if (!quiet) |
898 | pr_cont("\n [%#x] first element: %p, chain length: %u\n", | |
899 | i, tbl->buckets[i], cnt); | |
900 | } | |
901 | ||
97defe1e TG |
902 | pr_info(" Traversal complete: counted=%u, nelems=%u, entries=%d\n", |
903 | total, atomic_read(&ht->nelems), TEST_ENTRIES); | |
3e7b2ec4 | 904 | |
97defe1e | 905 | if (total != atomic_read(&ht->nelems) || total != TEST_ENTRIES) |
3e7b2ec4 | 906 | pr_warn("Test failed: Total count mismatch ^^^"); |
7e1e7763 TG |
907 | } |
908 | ||
909 | static int __init test_rhashtable(struct rhashtable *ht) | |
910 | { | |
911 | struct bucket_table *tbl; | |
88d6ed15 TG |
912 | struct test_obj *obj; |
913 | struct rhash_head *pos, *next; | |
7e1e7763 TG |
914 | int err; |
915 | unsigned int i; | |
916 | ||
917 | /* | |
918 | * Insertion Test: | |
919 | * Insert TEST_ENTRIES into table with all keys even numbers | |
920 | */ | |
921 | pr_info(" Adding %d keys\n", TEST_ENTRIES); | |
922 | for (i = 0; i < TEST_ENTRIES; i++) { | |
923 | struct test_obj *obj; | |
924 | ||
925 | obj = kzalloc(sizeof(*obj), GFP_KERNEL); | |
926 | if (!obj) { | |
927 | err = -ENOMEM; | |
928 | goto error; | |
929 | } | |
930 | ||
931 | obj->ptr = TEST_PTR; | |
932 | obj->value = i * 2; | |
933 | ||
6eba8224 | 934 | rhashtable_insert(ht, &obj->node); |
7e1e7763 TG |
935 | } |
936 | ||
937 | rcu_read_lock(); | |
3e7b2ec4 | 938 | test_bucket_stats(ht, true); |
7e1e7763 TG |
939 | test_rht_lookup(ht); |
940 | rcu_read_unlock(); | |
941 | ||
942 | for (i = 0; i < TEST_NEXPANDS; i++) { | |
943 | pr_info(" Table expansion iteration %u...\n", i); | |
97defe1e | 944 | mutex_lock(&ht->mutex); |
6eba8224 | 945 | rhashtable_expand(ht); |
97defe1e | 946 | mutex_unlock(&ht->mutex); |
7e1e7763 TG |
947 | |
948 | rcu_read_lock(); | |
949 | pr_info(" Verifying lookups...\n"); | |
950 | test_rht_lookup(ht); | |
951 | rcu_read_unlock(); | |
952 | } | |
953 | ||
954 | for (i = 0; i < TEST_NEXPANDS; i++) { | |
955 | pr_info(" Table shrinkage iteration %u...\n", i); | |
97defe1e | 956 | mutex_lock(&ht->mutex); |
6eba8224 | 957 | rhashtable_shrink(ht); |
97defe1e | 958 | mutex_unlock(&ht->mutex); |
7e1e7763 TG |
959 | |
960 | rcu_read_lock(); | |
961 | pr_info(" Verifying lookups...\n"); | |
962 | test_rht_lookup(ht); | |
963 | rcu_read_unlock(); | |
964 | } | |
965 | ||
3e7b2ec4 TG |
966 | rcu_read_lock(); |
967 | test_bucket_stats(ht, true); | |
968 | rcu_read_unlock(); | |
969 | ||
7e1e7763 TG |
970 | pr_info(" Deleting %d keys\n", TEST_ENTRIES); |
971 | for (i = 0; i < TEST_ENTRIES; i++) { | |
972 | u32 key = i * 2; | |
973 | ||
974 | obj = rhashtable_lookup(ht, &key); | |
975 | BUG_ON(!obj); | |
976 | ||
6eba8224 | 977 | rhashtable_remove(ht, &obj->node); |
7e1e7763 TG |
978 | kfree(obj); |
979 | } | |
980 | ||
981 | return 0; | |
982 | ||
983 | error: | |
984 | tbl = rht_dereference_rcu(ht->tbl, ht); | |
985 | for (i = 0; i < tbl->size; i++) | |
88d6ed15 | 986 | rht_for_each_entry_safe(obj, pos, next, tbl, i, node) |
7e1e7763 TG |
987 | kfree(obj); |
988 | ||
989 | return err; | |
990 | } | |
991 | ||
992 | static int __init test_rht_init(void) | |
993 | { | |
994 | struct rhashtable ht; | |
995 | struct rhashtable_params params = { | |
996 | .nelem_hint = TEST_HT_SIZE, | |
997 | .head_offset = offsetof(struct test_obj, node), | |
998 | .key_offset = offsetof(struct test_obj, value), | |
999 | .key_len = sizeof(int), | |
87545899 | 1000 | .hashfn = jhash, |
f89bd6f8 | 1001 | .nulls_base = (3U << RHT_BASE_SHIFT), |
7e1e7763 TG |
1002 | .grow_decision = rht_grow_above_75, |
1003 | .shrink_decision = rht_shrink_below_30, | |
1004 | }; | |
1005 | int err; | |
1006 | ||
1007 | pr_info("Running resizable hashtable tests...\n"); | |
1008 | ||
1009 | err = rhashtable_init(&ht, ¶ms); | |
1010 | if (err < 0) { | |
1011 | pr_warn("Test failed: Unable to initialize hashtable: %d\n", | |
1012 | err); | |
1013 | return err; | |
1014 | } | |
1015 | ||
1016 | err = test_rhashtable(&ht); | |
1017 | ||
1018 | rhashtable_destroy(&ht); | |
1019 | ||
1020 | return err; | |
1021 | } | |
1022 | ||
1023 | subsys_initcall(test_rht_init); | |
1024 | ||
1025 | #endif /* CONFIG_TEST_RHASHTABLE */ |