Commit | Line | Data |
---|---|---|
5e28c532 | 1 | /* |
abc490a1 MD |
2 | * rculfhash.c |
3 | * | |
4 | * Userspace RCU library - Lock-Free Expandable RCU Hash Table | |
5 | * | |
6 | * Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; either | |
11 | * version 2.1 of the License, or (at your option) any later version. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
5e28c532 MD |
21 | */ |
22 | ||
2ed95849 MD |
23 | #define _LGPL_SOURCE |
24 | #include <stdlib.h> | |
e0ba718a MD |
25 | #include <errno.h> |
26 | #include <assert.h> | |
27 | #include <stdio.h> | |
abc490a1 | 28 | #include <stdint.h> |
f000907d | 29 | #include <string.h> |
e0ba718a | 30 | |
2ed95849 | 31 | #include <urcu.h> |
abc490a1 | 32 | #include <urcu-call-rcu.h> |
a42cc659 MD |
33 | #include <urcu/arch.h> |
34 | #include <urcu/uatomic.h> | |
674f7a69 | 35 | #include <urcu/jhash.h> |
a42cc659 | 36 | #include <urcu/compiler.h> |
abc490a1 | 37 | #include <urcu/rculfhash.h> |
5e28c532 | 38 | #include <stdio.h> |
464a1ec9 | 39 | #include <pthread.h> |
44395fb7 | 40 | |
f9830efd MD |
41 | #define DEBUG /* Test */ |
42 | ||
43 | #ifdef DEBUG | |
44 | #define dbg_printf(args...) printf(args) | |
45 | #else | |
46 | #define dbg_printf(args...) | |
47 | #endif | |
48 | ||
3390d470 MD |
49 | #define CHAIN_LEN_TARGET 4 |
50 | #define CHAIN_LEN_RESIZE_THRESHOLD 16 | |
2ed95849 | 51 | |
abc490a1 MD |
52 | #ifndef max |
53 | #define max(a, b) ((a) > (b) ? (a) : (b)) | |
54 | #endif | |
2ed95849 | 55 | |
395270b6 | 56 | struct rcu_table { |
abc490a1 | 57 | unsigned long size; /* always a power of 2 */ |
f9830efd | 58 | unsigned long resize_target; |
abc490a1 | 59 | struct rcu_head head; |
395270b6 MD |
60 | struct rcu_ht_node *tbl[0]; |
61 | }; | |
62 | ||
2ed95849 | 63 | struct rcu_ht { |
395270b6 | 64 | struct rcu_table *t; /* shared */ |
2ed95849 | 65 | ht_hash_fct hash_fct; |
732ad076 MD |
66 | ht_compare_fct compare_fct; |
67 | unsigned long hash_seed; | |
464a1ec9 | 68 | pthread_mutex_t resize_mutex; /* resize mutex: add/del mutex */ |
abc490a1 MD |
69 | void (*ht_call_rcu)(struct rcu_head *head, |
70 | void (*func)(struct rcu_head *head)); | |
2ed95849 MD |
71 | }; |
72 | ||
abc490a1 MD |
73 | struct rcu_resize_work { |
74 | struct rcu_head head; | |
2ed95849 | 75 | struct rcu_ht *ht; |
abc490a1 | 76 | }; |
2ed95849 | 77 | |
abc490a1 MD |
78 | /* |
79 | * Algorithm to reverse bits in a word by lookup table, extended to | |
80 | * 64-bit words. | |
f9830efd | 81 | * Source: |
abc490a1 | 82 | * http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable |
f9830efd | 83 | * Originally from Public Domain. |
abc490a1 MD |
84 | */ |
85 | ||
86 | static const uint8_t BitReverseTable256[256] = | |
2ed95849 | 87 | { |
abc490a1 MD |
88 | #define R2(n) (n), (n) + 2*64, (n) + 1*64, (n) + 3*64 |
89 | #define R4(n) R2(n), R2((n) + 2*16), R2((n) + 1*16), R2((n) + 3*16) | |
90 | #define R6(n) R4(n), R4((n) + 2*4 ), R4((n) + 1*4 ), R4((n) + 3*4 ) | |
91 | R6(0), R6(2), R6(1), R6(3) | |
92 | }; | |
93 | #undef R2 | |
94 | #undef R4 | |
95 | #undef R6 | |
2ed95849 | 96 | |
abc490a1 MD |
97 | static |
98 | uint8_t bit_reverse_u8(uint8_t v) | |
99 | { | |
100 | return BitReverseTable256[v]; | |
101 | } | |
ab7d5fc6 | 102 | |
abc490a1 MD |
103 | static __attribute__((unused)) |
104 | uint32_t bit_reverse_u32(uint32_t v) | |
105 | { | |
106 | return ((uint32_t) bit_reverse_u8(v) << 24) | | |
107 | ((uint32_t) bit_reverse_u8(v >> 8) << 16) | | |
108 | ((uint32_t) bit_reverse_u8(v >> 16) << 8) | | |
109 | ((uint32_t) bit_reverse_u8(v >> 24)); | |
2ed95849 MD |
110 | } |
111 | ||
abc490a1 MD |
112 | static __attribute__((unused)) |
113 | uint64_t bit_reverse_u64(uint64_t v) | |
2ed95849 | 114 | { |
abc490a1 MD |
115 | return ((uint64_t) bit_reverse_u8(v) << 56) | |
116 | ((uint64_t) bit_reverse_u8(v >> 8) << 48) | | |
117 | ((uint64_t) bit_reverse_u8(v >> 16) << 40) | | |
118 | ((uint64_t) bit_reverse_u8(v >> 24) << 32) | | |
119 | ((uint64_t) bit_reverse_u8(v >> 32) << 24) | | |
120 | ((uint64_t) bit_reverse_u8(v >> 40) << 16) | | |
121 | ((uint64_t) bit_reverse_u8(v >> 48) << 8) | | |
122 | ((uint64_t) bit_reverse_u8(v >> 56)); | |
123 | } | |
124 | ||
125 | static | |
126 | unsigned long bit_reverse_ulong(unsigned long v) | |
127 | { | |
128 | #if (CAA_BITS_PER_LONG == 32) | |
129 | return bit_reverse_u32(v); | |
130 | #else | |
131 | return bit_reverse_u64(v); | |
132 | #endif | |
133 | } | |
134 | ||
f9830efd MD |
135 | /* |
136 | * Algorithm to find the log2 of a 32-bit unsigned integer. | |
137 | * source: http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogLookup | |
138 | * Originally from Public Domain. | |
139 | */ | |
140 | static const char LogTable256[256] = | |
141 | { | |
142 | #define LT(n) n, n, n, n, n, n, n, n, n, n, n, n, n, n, n, n | |
143 | -1, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, | |
144 | LT(4), LT(5), LT(5), LT(6), LT(6), LT(6), LT(6), | |
145 | LT(7), LT(7), LT(7), LT(7), LT(7), LT(7), LT(7), LT(7) | |
146 | }; | |
147 | ||
148 | uint32_t log2_u32(uint32_t v) | |
149 | { | |
150 | uint32_t t, tt; | |
151 | ||
152 | if ((tt = (v >> 16))) | |
153 | return (t = (tt >> 8)) | |
154 | ? 24 + LogTable256[t] | |
155 | : 16 + LogTable256[tt]; | |
156 | else | |
157 | return (t = (v >> 8)) | |
158 | ? 8 + LogTable256[t] | |
159 | : LogTable256[v]; | |
160 | } | |
161 | ||
162 | static | |
163 | void ht_resize_lazy(struct rcu_ht *ht, struct rcu_table *t, int growth); | |
164 | ||
165 | static | |
166 | void check_resize(struct rcu_ht *ht, struct rcu_table *t, | |
167 | uint32_t chain_len) | |
168 | { | |
3390d470 MD |
169 | if (chain_len >= CHAIN_LEN_RESIZE_THRESHOLD) |
170 | ht_resize_lazy(ht, t, | |
171 | log2_u32(chain_len - CHAIN_LEN_TARGET)); | |
f9830efd MD |
172 | } |
173 | ||
abc490a1 MD |
174 | static |
175 | struct rcu_ht_node *clear_flag(struct rcu_ht_node *node) | |
176 | { | |
177 | return (struct rcu_ht_node *) (((unsigned long) node) & ~0x1); | |
178 | } | |
179 | ||
180 | static | |
181 | int is_removed(struct rcu_ht_node *node) | |
182 | { | |
183 | return ((unsigned long) node) & 0x1; | |
184 | } | |
185 | ||
186 | static | |
187 | struct rcu_ht_node *flag_removed(struct rcu_ht_node *node) | |
188 | { | |
189 | return (struct rcu_ht_node *) (((unsigned long) node) | 0x1); | |
190 | } | |
191 | ||
192 | static | |
f9830efd | 193 | unsigned long _uatomic_max(unsigned long *ptr, unsigned long v) |
abc490a1 MD |
194 | { |
195 | unsigned long old1, old2; | |
196 | ||
197 | old1 = uatomic_read(ptr); | |
198 | do { | |
199 | old2 = old1; | |
200 | if (old2 >= v) | |
f9830efd | 201 | return old2; |
abc490a1 | 202 | } while ((old1 = uatomic_cmpxchg(ptr, old2, v)) != old2); |
f9830efd | 203 | return v; |
abc490a1 MD |
204 | } |
205 | ||
206 | static | |
f000907d | 207 | void _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node) |
abc490a1 MD |
208 | { |
209 | struct rcu_ht_node *iter_prev = NULL, *iter = NULL; | |
210 | ||
f000907d MD |
211 | if (!t->size) |
212 | return; | |
abc490a1 | 213 | for (;;) { |
f9830efd | 214 | uint32_t chain_len = 0; |
abc490a1 MD |
215 | |
216 | iter_prev = rcu_dereference(t->tbl[node->hash & (t->size - 1)]); | |
217 | assert(iter_prev); | |
218 | assert(iter_prev->reverse_hash <= node->reverse_hash); | |
219 | for (;;) { | |
220 | iter = clear_flag(rcu_dereference(iter_prev->next)); | |
221 | if (unlikely(!iter)) | |
222 | break; | |
dd4505e0 | 223 | if (iter->reverse_hash > node->reverse_hash) |
abc490a1 MD |
224 | break; |
225 | iter_prev = iter; | |
f000907d | 226 | check_resize(ht, t, ++chain_len); |
abc490a1 | 227 | } |
98f969fc MD |
228 | /* |
229 | * add in iter_prev->next: TODO: check for helping | |
230 | * delete, for lock-freedom... | |
231 | */ | |
abc490a1 MD |
232 | if (is_removed(iter)) |
233 | continue; | |
f000907d | 234 | assert(node != iter); |
abc490a1 | 235 | node->next = iter; |
f000907d | 236 | assert(iter_prev != node); |
abc490a1 MD |
237 | if (uatomic_cmpxchg(&iter_prev->next, iter, node) != iter) |
238 | continue; | |
f000907d | 239 | break; |
464a1ec9 | 240 | } |
abc490a1 | 241 | } |
464a1ec9 | 242 | |
abc490a1 MD |
243 | static |
244 | int _ht_remove(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node) | |
245 | { | |
246 | struct rcu_ht_node *iter_prev, *iter, *next, *old; | |
247 | unsigned long chain_len; | |
248 | int found, ret = 0; | |
249 | int flagged = 0; | |
5e28c532 | 250 | |
abc490a1 MD |
251 | retry: |
252 | chain_len = 0; | |
253 | found = 0; | |
254 | iter_prev = rcu_dereference(t->tbl[node->hash & (t->size - 1)]); | |
255 | assert(iter_prev); | |
256 | assert(iter_prev->reverse_hash <= node->reverse_hash); | |
2ed95849 | 257 | for (;;) { |
abc490a1 MD |
258 | iter = clear_flag(rcu_dereference(iter_prev->next)); |
259 | if (unlikely(!iter)) | |
260 | break; | |
dd4505e0 | 261 | if (unlikely(iter->reverse_hash > node->reverse_hash)) |
abc490a1 MD |
262 | break; |
263 | if (iter == node) { | |
264 | found = 1; | |
2ed95849 MD |
265 | break; |
266 | } | |
abc490a1 MD |
267 | iter_prev = iter; |
268 | } | |
269 | if (!found) { | |
270 | ret = -ENOENT; | |
271 | goto end; | |
272 | } | |
273 | next = rcu_dereference(iter->next); | |
274 | if (!flagged) { | |
275 | if (is_removed(next)) { | |
276 | ret = -ENOENT; | |
2ed95849 MD |
277 | goto end; |
278 | } | |
abc490a1 | 279 | /* set deletion flag */ |
f000907d MD |
280 | if ((old = uatomic_cmpxchg(&iter->next, next, |
281 | flag_removed(next))) != next) { | |
abc490a1 MD |
282 | if (old == flag_removed(next)) { |
283 | ret = -ENOENT; | |
284 | goto end; | |
285 | } else { | |
286 | goto retry; | |
287 | } | |
288 | } | |
289 | flagged = 1; | |
2ed95849 | 290 | } |
abc490a1 | 291 | /* |
98f969fc MD |
292 | * Remove the element from the list. |
293 | * Retry if there has been a concurrent add before us. | |
294 | * Retry if the prev node has been deleted. | |
295 | * There cannot be a concurrent delete for our position, because | |
296 | * we won the deletion flag cmpxchg. | |
297 | * If there is a concurrent add after us, our deletion flag | |
298 | * makes it busy-loop (FIXME: not lock-free). | |
abc490a1 MD |
299 | */ |
300 | if (uatomic_cmpxchg(&iter_prev->next, iter, clear_flag(next)) != iter) | |
301 | goto retry; | |
2ed95849 | 302 | end: |
2ed95849 | 303 | return ret; |
abc490a1 | 304 | } |
2ed95849 | 305 | |
abc490a1 MD |
306 | static |
307 | void init_table(struct rcu_ht *ht, struct rcu_table *t, | |
308 | unsigned long first, unsigned long len) | |
309 | { | |
310 | unsigned long i, end; | |
311 | ||
312 | end = first + len; | |
313 | for (i = first; i < end; i++) { | |
314 | /* Update table size when power of two */ | |
315 | if (i != 0 && !(i & (i - 1))) | |
316 | t->size = i; | |
317 | t->tbl[i] = calloc(1, sizeof(struct rcu_ht_node)); | |
318 | t->tbl[i]->dummy = 1; | |
319 | t->tbl[i]->hash = i; | |
320 | t->tbl[i]->reverse_hash = bit_reverse_ulong(i); | |
321 | _ht_add(ht, t, t->tbl[i]); | |
322 | } | |
f9830efd | 323 | t->resize_target = t->size = end; |
2ed95849 MD |
324 | } |
325 | ||
abc490a1 | 326 | struct rcu_ht *ht_new(ht_hash_fct hash_fct, |
732ad076 MD |
327 | ht_compare_fct compare_fct, |
328 | unsigned long hash_seed, | |
abc490a1 MD |
329 | unsigned long init_size, |
330 | void (*ht_call_rcu)(struct rcu_head *head, | |
331 | void (*func)(struct rcu_head *head))) | |
332 | { | |
333 | struct rcu_ht *ht; | |
334 | ||
335 | ht = calloc(1, sizeof(struct rcu_ht)); | |
336 | ht->hash_fct = hash_fct; | |
732ad076 MD |
337 | ht->compare_fct = compare_fct; |
338 | ht->hash_seed = hash_seed; | |
f000907d | 339 | ht->ht_call_rcu = ht_call_rcu; |
abc490a1 MD |
340 | /* this mutex should not nest in read-side C.S. */ |
341 | pthread_mutex_init(&ht->resize_mutex, NULL); | |
342 | ht->t = calloc(1, sizeof(struct rcu_table) | |
343 | + (max(init_size, 1) * sizeof(struct rcu_ht_node *))); | |
344 | ht->t->size = 0; | |
f000907d | 345 | pthread_mutex_lock(&ht->resize_mutex); |
abc490a1 | 346 | init_table(ht, ht->t, 0, max(init_size, 1)); |
f000907d | 347 | pthread_mutex_unlock(&ht->resize_mutex); |
abc490a1 MD |
348 | return ht; |
349 | } | |
350 | ||
732ad076 | 351 | struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key, size_t key_len) |
2ed95849 | 352 | { |
395270b6 | 353 | struct rcu_table *t; |
abc490a1 MD |
354 | struct rcu_ht_node *node; |
355 | unsigned long hash, reverse_hash; | |
2ed95849 | 356 | |
732ad076 | 357 | hash = ht->hash_fct(key, key_len, ht->hash_seed); |
abc490a1 | 358 | reverse_hash = bit_reverse_ulong(hash); |
464a1ec9 | 359 | |
395270b6 | 360 | t = rcu_dereference(ht->t); |
abc490a1 | 361 | node = rcu_dereference(t->tbl[hash & (t->size - 1)]); |
2ed95849 | 362 | for (;;) { |
abc490a1 MD |
363 | if (unlikely(!node)) |
364 | break; | |
dd4505e0 | 365 | if (unlikely(node->reverse_hash > reverse_hash)) { |
abc490a1 MD |
366 | node = NULL; |
367 | break; | |
2ed95849 | 368 | } |
732ad076 | 369 | if (!ht->compare_fct(node->key, node->key_len, key, key_len)) { |
dd4505e0 | 370 | if (unlikely(is_removed(rcu_dereference(node->next)))) |
abc490a1 | 371 | node = NULL; |
2ed95849 MD |
372 | break; |
373 | } | |
abc490a1 | 374 | node = clear_flag(rcu_dereference(node->next)); |
2ed95849 | 375 | } |
abc490a1 MD |
376 | return node; |
377 | } | |
e0ba718a | 378 | |
f000907d | 379 | void ht_add(struct rcu_ht *ht, struct rcu_ht_node *node) |
abc490a1 MD |
380 | { |
381 | struct rcu_table *t; | |
ab7d5fc6 | 382 | |
732ad076 | 383 | node->hash = ht->hash_fct(node->key, node->key_len, ht->hash_seed); |
abc490a1 | 384 | node->reverse_hash = bit_reverse_ulong((unsigned long) node->hash); |
2ed95849 | 385 | |
abc490a1 | 386 | t = rcu_dereference(ht->t); |
f000907d | 387 | _ht_add(ht, t, node); |
2ed95849 MD |
388 | } |
389 | ||
abc490a1 | 390 | int ht_remove(struct rcu_ht *ht, struct rcu_ht_node *node) |
2ed95849 | 391 | { |
abc490a1 MD |
392 | struct rcu_table *t; |
393 | ||
394 | t = rcu_dereference(ht->t); | |
abc490a1 | 395 | return _ht_remove(ht, t, node); |
2ed95849 | 396 | } |
ab7d5fc6 | 397 | |
abc490a1 MD |
398 | static |
399 | int ht_delete_dummy(struct rcu_ht *ht) | |
674f7a69 | 400 | { |
395270b6 | 401 | struct rcu_table *t; |
abc490a1 MD |
402 | struct rcu_ht_node *node; |
403 | unsigned long i; | |
674f7a69 | 404 | |
abc490a1 MD |
405 | t = ht->t; |
406 | /* Check that the table is empty */ | |
407 | node = t->tbl[0]; | |
408 | do { | |
409 | if (!node->dummy) | |
410 | return -EPERM; | |
411 | node = node->next; | |
412 | } while (node); | |
413 | /* Internal sanity check: all nodes left should be dummy */ | |
395270b6 | 414 | for (i = 0; i < t->size; i++) { |
abc490a1 MD |
415 | assert(t->tbl[i]->dummy); |
416 | free(t->tbl[i]); | |
674f7a69 | 417 | } |
abc490a1 | 418 | return 0; |
674f7a69 MD |
419 | } |
420 | ||
421 | /* | |
422 | * Should only be called when no more concurrent readers nor writers can | |
423 | * possibly access the table. | |
424 | */ | |
5e28c532 | 425 | int ht_destroy(struct rcu_ht *ht) |
674f7a69 | 426 | { |
5e28c532 MD |
427 | int ret; |
428 | ||
abc490a1 MD |
429 | ret = ht_delete_dummy(ht); |
430 | if (ret) | |
431 | return ret; | |
395270b6 | 432 | free(ht->t); |
674f7a69 | 433 | free(ht); |
5e28c532 | 434 | return ret; |
674f7a69 MD |
435 | } |
436 | ||
abc490a1 MD |
437 | static |
438 | void ht_free_table_cb(struct rcu_head *head) | |
439 | { | |
440 | struct rcu_table *t = | |
441 | caa_container_of(head, struct rcu_table, head); | |
442 | free(t); | |
443 | } | |
444 | ||
445 | /* called with resize mutex held */ | |
446 | static | |
447 | void _do_ht_resize(struct rcu_ht *ht) | |
464a1ec9 | 448 | { |
abc490a1 | 449 | unsigned long new_size, old_size; |
395270b6 | 450 | struct rcu_table *new_t, *old_t; |
464a1ec9 | 451 | |
395270b6 MD |
452 | old_t = ht->t; |
453 | old_size = old_t->size; | |
464a1ec9 | 454 | |
f9830efd MD |
455 | new_size = CMM_LOAD_SHARED(old_t->resize_target); |
456 | dbg_printf("rculfhash: resize from %lu to %lu buckets\n", | |
457 | old_size, new_size); | |
abc490a1 | 458 | if (old_size == new_size) |
464a1ec9 | 459 | return; |
f000907d | 460 | new_t = malloc(sizeof(struct rcu_table) |
abc490a1 | 461 | + (new_size * sizeof(struct rcu_ht_node *))); |
f000907d MD |
462 | assert(new_size > old_size); |
463 | memcpy(&new_t->tbl, &old_t->tbl, | |
464 | old_size * sizeof(struct rcu_ht_node *)); | |
465 | init_table(ht, new_t, old_size, new_size - old_size); | |
f000907d MD |
466 | /* Changing table and size atomically wrt lookups */ |
467 | rcu_assign_pointer(ht->t, new_t); | |
468 | ht->ht_call_rcu(&old_t->head, ht_free_table_cb); | |
464a1ec9 MD |
469 | } |
470 | ||
abc490a1 | 471 | static |
f9830efd MD |
472 | unsigned long resize_target_update(struct rcu_table *t, |
473 | int growth_order) | |
464a1ec9 | 474 | { |
f9830efd MD |
475 | return _uatomic_max(&t->resize_target, |
476 | t->size << growth_order); | |
464a1ec9 MD |
477 | } |
478 | ||
464a1ec9 MD |
479 | void ht_resize(struct rcu_ht *ht, int growth) |
480 | { | |
f9830efd MD |
481 | struct rcu_table *t = rcu_dereference(ht->t); |
482 | unsigned long target_size; | |
483 | ||
484 | target_size = resize_target_update(t, growth); | |
485 | if (t->size < target_size) { | |
486 | pthread_mutex_lock(&ht->resize_mutex); | |
487 | _do_ht_resize(ht); | |
488 | pthread_mutex_unlock(&ht->resize_mutex); | |
489 | } | |
abc490a1 | 490 | } |
464a1ec9 | 491 | |
abc490a1 MD |
492 | static |
493 | void do_resize_cb(struct rcu_head *head) | |
494 | { | |
495 | struct rcu_resize_work *work = | |
496 | caa_container_of(head, struct rcu_resize_work, head); | |
497 | struct rcu_ht *ht = work->ht; | |
498 | ||
499 | pthread_mutex_lock(&ht->resize_mutex); | |
500 | _do_ht_resize(ht); | |
501 | pthread_mutex_unlock(&ht->resize_mutex); | |
502 | free(work); | |
464a1ec9 MD |
503 | } |
504 | ||
abc490a1 | 505 | static |
f000907d | 506 | void ht_resize_lazy(struct rcu_ht *ht, struct rcu_table *t, int growth) |
ab7d5fc6 | 507 | { |
abc490a1 | 508 | struct rcu_resize_work *work; |
f9830efd | 509 | unsigned long target_size; |
abc490a1 | 510 | |
f9830efd MD |
511 | target_size = resize_target_update(t, growth); |
512 | if (t->size < target_size) { | |
513 | work = malloc(sizeof(*work)); | |
514 | work->ht = ht; | |
515 | ht->ht_call_rcu(&work->head, do_resize_cb); | |
516 | } | |
ab7d5fc6 | 517 | } |