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e80aa729 NS |
1 | /* |
2 | * Copyright (c) 2006 Silicon Graphics, Inc. | |
3 | * All Rights Reserved. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it would be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
17 | */ | |
18 | ||
19 | #include <stdio.h> | |
20 | #include <stdlib.h> | |
21 | #include <string.h> | |
22 | #include <unistd.h> | |
23 | #include <pthread.h> | |
24 | ||
9c799827 | 25 | #include "libxfs_priv.h" |
b626fb59 DC |
26 | #include "xfs_fs.h" |
27 | #include "xfs_shared.h" | |
28 | #include "xfs_format.h" | |
29 | #include "xfs_trans_resv.h" | |
30 | #include "xfs_mount.h" | |
31 | #include "xfs_bit.h" | |
e80aa729 NS |
32 | |
33 | #define CACHE_DEBUG 1 | |
00418cb4 NS |
34 | #undef CACHE_DEBUG |
35 | #define CACHE_DEBUG 1 | |
36 | #undef CACHE_ABORT | |
37 | /* #define CACHE_ABORT 1 */ | |
e80aa729 | 38 | |
69ec88b5 BN |
39 | #define CACHE_SHAKE_COUNT 64 |
40 | ||
1c4110bd NS |
41 | static unsigned int cache_generic_bulkrelse(struct cache *, struct list_head *); |
42 | ||
e80aa729 NS |
43 | struct cache * |
44 | cache_init( | |
ba9ecd40 | 45 | int flags, |
e80aa729 NS |
46 | unsigned int hashsize, |
47 | struct cache_operations *cache_operations) | |
48 | { | |
49 | struct cache * cache; | |
50 | unsigned int i, maxcount; | |
51 | ||
b6281496 | 52 | maxcount = hashsize * HASH_CACHE_RATIO; |
e80aa729 NS |
53 | |
54 | if (!(cache = malloc(sizeof(struct cache)))) | |
55 | return NULL; | |
56 | if (!(cache->c_hash = calloc(hashsize, sizeof(struct cache_hash)))) { | |
57 | free(cache); | |
58 | return NULL; | |
59 | } | |
60 | ||
ba9ecd40 | 61 | cache->c_flags = flags; |
e80aa729 | 62 | cache->c_count = 0; |
9f38f08d MV |
63 | cache->c_max = 0; |
64 | cache->c_hits = 0; | |
65 | cache->c_misses = 0; | |
e80aa729 NS |
66 | cache->c_maxcount = maxcount; |
67 | cache->c_hashsize = hashsize; | |
602dcc0e | 68 | cache->c_hashshift = libxfs_highbit32(hashsize); |
e80aa729 NS |
69 | cache->hash = cache_operations->hash; |
70 | cache->alloc = cache_operations->alloc; | |
33165ec3 | 71 | cache->flush = cache_operations->flush; |
e80aa729 NS |
72 | cache->relse = cache_operations->relse; |
73 | cache->compare = cache_operations->compare; | |
1c4110bd NS |
74 | cache->bulkrelse = cache_operations->bulkrelse ? |
75 | cache_operations->bulkrelse : cache_generic_bulkrelse; | |
e80aa729 NS |
76 | pthread_mutex_init(&cache->c_mutex, NULL); |
77 | ||
78 | for (i = 0; i < hashsize; i++) { | |
79 | list_head_init(&cache->c_hash[i].ch_list); | |
b6281496 | 80 | cache->c_hash[i].ch_count = 0; |
e80aa729 NS |
81 | pthread_mutex_init(&cache->c_hash[i].ch_mutex, NULL); |
82 | } | |
69ec88b5 | 83 | |
aef29e17 | 84 | for (i = 0; i <= CACHE_DIRTY_PRIORITY; i++) { |
69ec88b5 BN |
85 | list_head_init(&cache->c_mrus[i].cm_list); |
86 | cache->c_mrus[i].cm_count = 0; | |
87 | pthread_mutex_init(&cache->c_mrus[i].cm_mutex, NULL); | |
88 | } | |
e80aa729 NS |
89 | return cache; |
90 | } | |
91 | ||
631596d2 ES |
92 | void |
93 | cache_expand( | |
94 | struct cache * cache) | |
95 | { | |
96 | pthread_mutex_lock(&cache->c_mutex); | |
97 | #ifdef CACHE_DEBUG | |
98 | fprintf(stderr, "doubling cache size to %d\n", 2 * cache->c_maxcount); | |
99 | #endif | |
100 | cache->c_maxcount *= 2; | |
101 | pthread_mutex_unlock(&cache->c_mutex); | |
102 | } | |
103 | ||
e80aa729 NS |
104 | void |
105 | cache_walk( | |
106 | struct cache * cache, | |
107 | cache_walk_t visit) | |
108 | { | |
109 | struct cache_hash * hash; | |
110 | struct list_head * head; | |
111 | struct list_head * pos; | |
112 | unsigned int i; | |
113 | ||
114 | for (i = 0; i < cache->c_hashsize; i++) { | |
115 | hash = &cache->c_hash[i]; | |
116 | head = &hash->ch_list; | |
117 | pthread_mutex_lock(&hash->ch_mutex); | |
118 | for (pos = head->next; pos != head; pos = pos->next) | |
119 | visit((struct cache_node *)pos); | |
120 | pthread_mutex_unlock(&hash->ch_mutex); | |
121 | } | |
122 | } | |
123 | ||
00418cb4 NS |
124 | #ifdef CACHE_ABORT |
125 | #define cache_abort() abort() | |
126 | #else | |
127 | #define cache_abort() do { } while (0) | |
128 | #endif | |
129 | ||
e80aa729 NS |
130 | #ifdef CACHE_DEBUG |
131 | static void | |
132 | cache_zero_check( | |
133 | struct cache_node * node) | |
134 | { | |
135 | if (node->cn_count > 0) { | |
136 | fprintf(stderr, "%s: refcount is %u, not zero (node=%p)\n", | |
137 | __FUNCTION__, node->cn_count, node); | |
00418cb4 | 138 | cache_abort(); |
e80aa729 NS |
139 | } |
140 | } | |
141 | #define cache_destroy_check(c) cache_walk((c), cache_zero_check) | |
142 | #else | |
143 | #define cache_destroy_check(c) do { } while (0) | |
144 | #endif | |
145 | ||
146 | void | |
147 | cache_destroy( | |
148 | struct cache * cache) | |
149 | { | |
150 | unsigned int i; | |
151 | ||
152 | cache_destroy_check(cache); | |
153 | for (i = 0; i < cache->c_hashsize; i++) { | |
154 | list_head_destroy(&cache->c_hash[i].ch_list); | |
155 | pthread_mutex_destroy(&cache->c_hash[i].ch_mutex); | |
156 | } | |
aef29e17 | 157 | for (i = 0; i <= CACHE_DIRTY_PRIORITY; i++) { |
69ec88b5 BN |
158 | list_head_destroy(&cache->c_mrus[i].cm_list); |
159 | pthread_mutex_destroy(&cache->c_mrus[i].cm_mutex); | |
160 | } | |
e80aa729 NS |
161 | pthread_mutex_destroy(&cache->c_mutex); |
162 | free(cache->c_hash); | |
163 | free(cache); | |
164 | } | |
165 | ||
69ec88b5 BN |
166 | static unsigned int |
167 | cache_generic_bulkrelse( | |
e80aa729 | 168 | struct cache * cache, |
69ec88b5 | 169 | struct list_head * list) |
e80aa729 | 170 | { |
69ec88b5 BN |
171 | struct cache_node * node; |
172 | unsigned int count = 0; | |
e80aa729 | 173 | |
69ec88b5 BN |
174 | while (!list_empty(list)) { |
175 | node = list_entry(list->next, struct cache_node, cn_mru); | |
e80aa729 | 176 | pthread_mutex_destroy(&node->cn_mutex); |
69ec88b5 | 177 | list_del_init(&node->cn_mru); |
e80aa729 | 178 | cache->relse(node); |
69ec88b5 | 179 | count++; |
e80aa729 | 180 | } |
69ec88b5 | 181 | |
e80aa729 NS |
182 | return count; |
183 | } | |
184 | ||
185 | /* | |
aef29e17 DC |
186 | * Park unflushable nodes on their own special MRU so that cache_shake() doesn't |
187 | * end up repeatedly scanning them in the futile attempt to clean them before | |
188 | * reclaim. | |
189 | */ | |
190 | static void | |
191 | cache_add_to_dirty_mru( | |
192 | struct cache *cache, | |
193 | struct cache_node *node) | |
194 | { | |
195 | struct cache_mru *mru = &cache->c_mrus[CACHE_DIRTY_PRIORITY]; | |
196 | ||
197 | pthread_mutex_lock(&mru->cm_mutex); | |
1b9fecf7 | 198 | node->cn_old_priority = node->cn_priority; |
aef29e17 DC |
199 | node->cn_priority = CACHE_DIRTY_PRIORITY; |
200 | list_add(&node->cn_mru, &mru->cm_list); | |
201 | mru->cm_count++; | |
202 | pthread_mutex_unlock(&mru->cm_mutex); | |
203 | } | |
204 | ||
205 | /* | |
206 | * We've hit the limit on cache size, so we need to start reclaiming nodes we've | |
207 | * used. The MRU specified by the priority is shaken. Returns new priority at | |
208 | * end of the call (in case we call again). We are not allowed to reclaim dirty | |
209 | * objects, so we have to flush them first. If flushing fails, we move them to | |
210 | * the "dirty, unreclaimable" list. | |
211 | * | |
212 | * Hence we skip priorities > CACHE_MAX_PRIORITY unless "purge" is set as we | |
213 | * park unflushable (and hence unreclaimable) buffers at these priorities. | |
214 | * Trying to shake unreclaimable buffer lists when there is memory pressure is a | |
215 | * waste of time and CPU and greatly slows down cache node recycling operations. | |
216 | * Hence we only try to free them if we are being asked to purge the cache of | |
217 | * all entries. | |
e80aa729 NS |
218 | */ |
219 | static unsigned int | |
69ec88b5 | 220 | cache_shake( |
e80aa729 | 221 | struct cache * cache, |
69ec88b5 | 222 | unsigned int priority, |
aef29e17 | 223 | bool purge) |
e80aa729 | 224 | { |
69ec88b5 BN |
225 | struct cache_mru *mru; |
226 | struct cache_hash * hash; | |
e80aa729 NS |
227 | struct list_head temp; |
228 | struct list_head * head; | |
229 | struct list_head * pos; | |
230 | struct list_head * n; | |
231 | struct cache_node * node; | |
69ec88b5 | 232 | unsigned int count; |
e80aa729 | 233 | |
aef29e17 DC |
234 | ASSERT(priority <= CACHE_DIRTY_PRIORITY); |
235 | if (priority > CACHE_MAX_PRIORITY && !purge) | |
69ec88b5 BN |
236 | priority = 0; |
237 | ||
238 | mru = &cache->c_mrus[priority]; | |
239 | count = 0; | |
e80aa729 | 240 | list_head_init(&temp); |
69ec88b5 BN |
241 | head = &mru->cm_list; |
242 | ||
243 | pthread_mutex_lock(&mru->cm_mutex); | |
244 | for (pos = head->prev, n = pos->prev; pos != head; | |
245 | pos = n, n = pos->prev) { | |
246 | node = list_entry(pos, struct cache_node, cn_mru); | |
247 | ||
248 | if (pthread_mutex_trylock(&node->cn_mutex) != 0) | |
249 | continue; | |
250 | ||
aef29e17 DC |
251 | /* memory pressure is not allowed to release dirty objects */ |
252 | if (cache->flush(node) && !purge) { | |
253 | list_del(&node->cn_mru); | |
254 | mru->cm_count--; | |
255 | node->cn_priority = -1; | |
0a7942b3 | 256 | pthread_mutex_unlock(&node->cn_mutex); |
aef29e17 | 257 | cache_add_to_dirty_mru(cache, node); |
0a7942b3 DC |
258 | continue; |
259 | } | |
260 | ||
69ec88b5 | 261 | hash = cache->c_hash + node->cn_hashidx; |
a040d7c9 | 262 | if (pthread_mutex_trylock(&hash->ch_mutex) != 0) { |
69ec88b5 BN |
263 | pthread_mutex_unlock(&node->cn_mutex); |
264 | continue; | |
b6281496 | 265 | } |
a040d7c9 | 266 | ASSERT(node->cn_count == 0); |
69ec88b5 BN |
267 | ASSERT(node->cn_priority == priority); |
268 | node->cn_priority = -1; | |
1c4110bd | 269 | |
69ec88b5 BN |
270 | list_move(&node->cn_mru, &temp); |
271 | list_del_init(&node->cn_hash); | |
272 | hash->ch_count--; | |
273 | mru->cm_count--; | |
274 | pthread_mutex_unlock(&hash->ch_mutex); | |
275 | pthread_mutex_unlock(&node->cn_mutex); | |
1c4110bd | 276 | |
e80aa729 | 277 | count++; |
aef29e17 | 278 | if (!purge && count == CACHE_SHAKE_COUNT) |
69ec88b5 | 279 | break; |
e80aa729 | 280 | } |
69ec88b5 | 281 | pthread_mutex_unlock(&mru->cm_mutex); |
e80aa729 | 282 | |
69ec88b5 BN |
283 | if (count > 0) { |
284 | cache->bulkrelse(cache, &temp); | |
e80aa729 | 285 | |
e80aa729 NS |
286 | pthread_mutex_lock(&cache->c_mutex); |
287 | cache->c_count -= count; | |
288 | pthread_mutex_unlock(&cache->c_mutex); | |
289 | } | |
69ec88b5 BN |
290 | |
291 | return (count == CACHE_SHAKE_COUNT) ? priority : ++priority; | |
e80aa729 NS |
292 | } |
293 | ||
294 | /* | |
295 | * Allocate a new hash node (updating atomic counter in the process), | |
296 | * unless doing so will push us over the maximum cache size. | |
297 | */ | |
69ec88b5 | 298 | static struct cache_node * |
e80aa729 NS |
299 | cache_node_allocate( |
300 | struct cache * cache, | |
2556c98b | 301 | cache_key_t key) |
e80aa729 NS |
302 | { |
303 | unsigned int nodesfree; | |
304 | struct cache_node * node; | |
305 | ||
306 | pthread_mutex_lock(&cache->c_mutex); | |
69ec88b5 BN |
307 | nodesfree = (cache->c_count < cache->c_maxcount); |
308 | if (nodesfree) { | |
e80aa729 | 309 | cache->c_count++; |
9f38f08d MV |
310 | if (cache->c_count > cache->c_max) |
311 | cache->c_max = cache->c_count; | |
312 | } | |
313 | cache->c_misses++; | |
e80aa729 NS |
314 | pthread_mutex_unlock(&cache->c_mutex); |
315 | if (!nodesfree) | |
316 | return NULL; | |
69ec88b5 BN |
317 | node = cache->alloc(key); |
318 | if (node == NULL) { /* uh-oh */ | |
e80aa729 NS |
319 | pthread_mutex_lock(&cache->c_mutex); |
320 | cache->c_count--; | |
321 | pthread_mutex_unlock(&cache->c_mutex); | |
322 | return NULL; | |
323 | } | |
324 | pthread_mutex_init(&node->cn_mutex, NULL); | |
a040d7c9 | 325 | list_head_init(&node->cn_mru); |
e80aa729 | 326 | node->cn_count = 1; |
69ec88b5 | 327 | node->cn_priority = 0; |
1b9fecf7 | 328 | node->cn_old_priority = -1; |
e80aa729 NS |
329 | return node; |
330 | } | |
331 | ||
2556c98b BN |
332 | int |
333 | cache_overflowed( | |
334 | struct cache * cache) | |
335 | { | |
af43ca9f | 336 | return cache->c_maxcount == cache->c_max; |
2556c98b BN |
337 | } |
338 | ||
ba9ecd40 DC |
339 | |
340 | static int | |
341 | __cache_node_purge( | |
342 | struct cache * cache, | |
343 | struct cache_node * node) | |
344 | { | |
345 | int count; | |
346 | struct cache_mru * mru; | |
347 | ||
348 | pthread_mutex_lock(&node->cn_mutex); | |
349 | count = node->cn_count; | |
350 | if (count != 0) { | |
351 | pthread_mutex_unlock(&node->cn_mutex); | |
352 | return count; | |
353 | } | |
0a7942b3 DC |
354 | |
355 | /* can't purge dirty objects */ | |
356 | if (cache->flush(node)) { | |
357 | pthread_mutex_unlock(&node->cn_mutex); | |
358 | return 1; | |
359 | } | |
360 | ||
ba9ecd40 DC |
361 | mru = &cache->c_mrus[node->cn_priority]; |
362 | pthread_mutex_lock(&mru->cm_mutex); | |
363 | list_del_init(&node->cn_mru); | |
364 | mru->cm_count--; | |
365 | pthread_mutex_unlock(&mru->cm_mutex); | |
366 | ||
367 | pthread_mutex_unlock(&node->cn_mutex); | |
368 | pthread_mutex_destroy(&node->cn_mutex); | |
369 | list_del_init(&node->cn_hash); | |
370 | cache->relse(node); | |
0a7942b3 | 371 | return 0; |
ba9ecd40 DC |
372 | } |
373 | ||
e80aa729 NS |
374 | /* |
375 | * Lookup in the cache hash table. With any luck we'll get a cache | |
376 | * hit, in which case this will all be over quickly and painlessly. | |
377 | * Otherwise, we allocate a new node, taking care not to expand the | |
378 | * cache beyond the requested maximum size (shrink it if it would). | |
379 | * Returns one if hit in cache, otherwise zero. A node is _always_ | |
380 | * returned, however. | |
381 | */ | |
382 | int | |
383 | cache_node_get( | |
384 | struct cache * cache, | |
385 | cache_key_t key, | |
386 | struct cache_node ** nodep) | |
387 | { | |
388 | struct cache_node * node = NULL; | |
389 | struct cache_hash * hash; | |
69ec88b5 | 390 | struct cache_mru * mru; |
e80aa729 NS |
391 | struct list_head * head; |
392 | struct list_head * pos; | |
ba9ecd40 | 393 | struct list_head * n; |
69ec88b5 | 394 | unsigned int hashidx; |
e80aa729 | 395 | int priority = 0; |
ba9ecd40 | 396 | int purged = 0; |
e80aa729 | 397 | |
602dcc0e | 398 | hashidx = cache->hash(key, cache->c_hashsize, cache->c_hashshift); |
69ec88b5 | 399 | hash = cache->c_hash + hashidx; |
e80aa729 NS |
400 | head = &hash->ch_list; |
401 | ||
69ec88b5 BN |
402 | for (;;) { |
403 | pthread_mutex_lock(&hash->ch_mutex); | |
ba9ecd40 DC |
404 | for (pos = head->next, n = pos->next; pos != head; |
405 | pos = n, n = pos->next) { | |
406 | int result; | |
407 | ||
69ec88b5 | 408 | node = list_entry(pos, struct cache_node, cn_hash); |
ba9ecd40 DC |
409 | result = cache->compare(node, key); |
410 | switch (result) { | |
411 | case CACHE_HIT: | |
412 | break; | |
413 | case CACHE_PURGE: | |
414 | if ((cache->c_flags & CACHE_MISCOMPARE_PURGE) && | |
415 | !__cache_node_purge(cache, node)) { | |
416 | purged++; | |
417 | hash->ch_count--; | |
418 | } | |
419 | /* FALL THROUGH */ | |
420 | case CACHE_MISS: | |
421 | goto next_object; | |
422 | } | |
423 | ||
69ec88b5 | 424 | /* |
a040d7c9 BN |
425 | * node found, bump node's reference count, remove it |
426 | * from its MRU list, and update stats. | |
427 | */ | |
69ec88b5 | 428 | pthread_mutex_lock(&node->cn_mutex); |
69ec88b5 | 429 | |
a040d7c9 BN |
430 | if (node->cn_count == 0) { |
431 | ASSERT(node->cn_priority >= 0); | |
432 | ASSERT(!list_empty(&node->cn_mru)); | |
433 | mru = &cache->c_mrus[node->cn_priority]; | |
434 | pthread_mutex_lock(&mru->cm_mutex); | |
435 | mru->cm_count--; | |
436 | list_del_init(&node->cn_mru); | |
437 | pthread_mutex_unlock(&mru->cm_mutex); | |
1b9fecf7 DC |
438 | if (node->cn_old_priority != -1) { |
439 | ASSERT(node->cn_priority == | |
440 | CACHE_DIRTY_PRIORITY); | |
441 | node->cn_priority = node->cn_old_priority; | |
442 | node->cn_old_priority = -1; | |
443 | } | |
a040d7c9 BN |
444 | } |
445 | node->cn_count++; | |
69ec88b5 BN |
446 | |
447 | pthread_mutex_unlock(&node->cn_mutex); | |
448 | pthread_mutex_unlock(&hash->ch_mutex); | |
449 | ||
450 | pthread_mutex_lock(&cache->c_mutex); | |
451 | cache->c_hits++; | |
452 | pthread_mutex_unlock(&cache->c_mutex); | |
453 | ||
454 | *nodep = node; | |
455 | return 0; | |
ba9ecd40 DC |
456 | next_object: |
457 | continue; /* what the hell, gcc? */ | |
e80aa729 | 458 | } |
69ec88b5 BN |
459 | pthread_mutex_unlock(&hash->ch_mutex); |
460 | /* | |
461 | * not found, allocate a new entry | |
462 | */ | |
463 | node = cache_node_allocate(cache, key); | |
464 | if (node) | |
465 | break; | |
aef29e17 | 466 | priority = cache_shake(cache, priority, false); |
631596d2 ES |
467 | /* |
468 | * We start at 0; if we free CACHE_SHAKE_COUNT we get | |
469 | * back the same priority, if not we get back priority+1. | |
470 | * If we exceed CACHE_MAX_PRIORITY all slots are full; grow it. | |
471 | */ | |
472 | if (priority > CACHE_MAX_PRIORITY) { | |
473 | priority = 0; | |
474 | cache_expand(cache); | |
475 | } | |
e80aa729 | 476 | } |
69ec88b5 BN |
477 | |
478 | node->cn_hashidx = hashidx; | |
479 | ||
a040d7c9 | 480 | /* add new node to appropriate hash */ |
69ec88b5 BN |
481 | pthread_mutex_lock(&hash->ch_mutex); |
482 | hash->ch_count++; | |
69ec88b5 | 483 | list_add(&node->cn_hash, &hash->ch_list); |
e80aa729 | 484 | pthread_mutex_unlock(&hash->ch_mutex); |
69ec88b5 | 485 | |
ba9ecd40 DC |
486 | if (purged) { |
487 | pthread_mutex_lock(&cache->c_mutex); | |
488 | cache->c_count -= purged; | |
489 | pthread_mutex_unlock(&cache->c_mutex); | |
490 | } | |
491 | ||
e80aa729 | 492 | *nodep = node; |
69ec88b5 | 493 | return 1; |
e80aa729 NS |
494 | } |
495 | ||
496 | void | |
497 | cache_node_put( | |
a040d7c9 | 498 | struct cache * cache, |
e80aa729 NS |
499 | struct cache_node * node) |
500 | { | |
a040d7c9 BN |
501 | struct cache_mru * mru; |
502 | ||
e80aa729 NS |
503 | pthread_mutex_lock(&node->cn_mutex); |
504 | #ifdef CACHE_DEBUG | |
505 | if (node->cn_count < 1) { | |
506 | fprintf(stderr, "%s: node put on refcount %u (node=%p)\n", | |
507 | __FUNCTION__, node->cn_count, node); | |
00418cb4 | 508 | cache_abort(); |
e80aa729 | 509 | } |
a040d7c9 BN |
510 | if (!list_empty(&node->cn_mru)) { |
511 | fprintf(stderr, "%s: node put on node (%p) in MRU list\n", | |
512 | __FUNCTION__, node); | |
513 | cache_abort(); | |
514 | } | |
e80aa729 NS |
515 | #endif |
516 | node->cn_count--; | |
a040d7c9 BN |
517 | |
518 | if (node->cn_count == 0) { | |
519 | /* add unreferenced node to appropriate MRU for shaker */ | |
520 | mru = &cache->c_mrus[node->cn_priority]; | |
521 | pthread_mutex_lock(&mru->cm_mutex); | |
522 | mru->cm_count++; | |
523 | list_add(&node->cn_mru, &mru->cm_list); | |
524 | pthread_mutex_unlock(&mru->cm_mutex); | |
525 | } | |
526 | ||
e80aa729 NS |
527 | pthread_mutex_unlock(&node->cn_mutex); |
528 | } | |
529 | ||
69ec88b5 BN |
530 | void |
531 | cache_node_set_priority( | |
532 | struct cache * cache, | |
533 | struct cache_node * node, | |
534 | int priority) | |
535 | { | |
69ec88b5 BN |
536 | if (priority < 0) |
537 | priority = 0; | |
538 | else if (priority > CACHE_MAX_PRIORITY) | |
539 | priority = CACHE_MAX_PRIORITY; | |
540 | ||
541 | pthread_mutex_lock(&node->cn_mutex); | |
69ec88b5 | 542 | ASSERT(node->cn_count > 0); |
69ec88b5 | 543 | node->cn_priority = priority; |
1b9fecf7 | 544 | node->cn_old_priority = -1; |
69ec88b5 BN |
545 | pthread_mutex_unlock(&node->cn_mutex); |
546 | } | |
547 | ||
548 | int | |
549 | cache_node_get_priority( | |
550 | struct cache_node * node) | |
551 | { | |
552 | int priority; | |
553 | ||
554 | pthread_mutex_lock(&node->cn_mutex); | |
555 | priority = node->cn_priority; | |
556 | pthread_mutex_unlock(&node->cn_mutex); | |
557 | ||
558 | return priority; | |
559 | } | |
560 | ||
561 | ||
e80aa729 NS |
562 | /* |
563 | * Purge a specific node from the cache. Reference count must be zero. | |
564 | */ | |
565 | int | |
566 | cache_node_purge( | |
567 | struct cache * cache, | |
568 | cache_key_t key, | |
569 | struct cache_node * node) | |
570 | { | |
69ec88b5 BN |
571 | struct list_head * head; |
572 | struct list_head * pos; | |
573 | struct list_head * n; | |
574 | struct cache_hash * hash; | |
69ec88b5 BN |
575 | int count = -1; |
576 | ||
602dcc0e DC |
577 | hash = cache->c_hash + cache->hash(key, cache->c_hashsize, |
578 | cache->c_hashshift); | |
69ec88b5 BN |
579 | head = &hash->ch_list; |
580 | pthread_mutex_lock(&hash->ch_mutex); | |
581 | for (pos = head->next, n = pos->next; pos != head; | |
582 | pos = n, n = pos->next) { | |
583 | if ((struct cache_node *)pos != node) | |
584 | continue; | |
e80aa729 | 585 | |
ba9ecd40 DC |
586 | count = __cache_node_purge(cache, node); |
587 | if (!count) | |
588 | hash->ch_count--; | |
69ec88b5 BN |
589 | break; |
590 | } | |
591 | pthread_mutex_unlock(&hash->ch_mutex); | |
592 | ||
593 | if (count == 0) { | |
e80aa729 NS |
594 | pthread_mutex_lock(&cache->c_mutex); |
595 | cache->c_count--; | |
596 | pthread_mutex_unlock(&cache->c_mutex); | |
597 | } | |
598 | #ifdef CACHE_DEBUG | |
69ec88b5 | 599 | if (count >= 1) { |
e80aa729 | 600 | fprintf(stderr, "%s: refcount was %u, not zero (node=%p)\n", |
69ec88b5 | 601 | __FUNCTION__, count, node); |
00418cb4 | 602 | cache_abort(); |
e80aa729 | 603 | } |
69ec88b5 | 604 | if (count == -1) { |
e80aa729 NS |
605 | fprintf(stderr, "%s: purge node not found! (node=%p)\n", |
606 | __FUNCTION__, node); | |
00418cb4 | 607 | cache_abort(); |
e80aa729 NS |
608 | } |
609 | #endif | |
af43ca9f | 610 | return count == 0; |
e80aa729 NS |
611 | } |
612 | ||
613 | /* | |
614 | * Purge all nodes from the cache. All reference counts must be zero. | |
615 | */ | |
616 | void | |
617 | cache_purge( | |
618 | struct cache * cache) | |
619 | { | |
69ec88b5 BN |
620 | int i; |
621 | ||
aef29e17 DC |
622 | for (i = 0; i <= CACHE_DIRTY_PRIORITY; i++) |
623 | cache_shake(cache, i, true); | |
e80aa729 | 624 | |
e80aa729 NS |
625 | #ifdef CACHE_DEBUG |
626 | if (cache->c_count != 0) { | |
69ec88b5 BN |
627 | /* flush referenced nodes to disk */ |
628 | cache_flush(cache); | |
e80aa729 NS |
629 | fprintf(stderr, "%s: shake on cache %p left %u nodes!?\n", |
630 | __FUNCTION__, cache, cache->c_count); | |
00418cb4 | 631 | cache_abort(); |
e80aa729 NS |
632 | } |
633 | #endif | |
33165ec3 BN |
634 | } |
635 | ||
636 | /* | |
2556c98b | 637 | * Flush all nodes in the cache to disk. |
33165ec3 BN |
638 | */ |
639 | void | |
640 | cache_flush( | |
641 | struct cache * cache) | |
642 | { | |
643 | struct cache_hash * hash; | |
644 | struct list_head * head; | |
645 | struct list_head * pos; | |
646 | struct cache_node * node; | |
647 | int i; | |
2556c98b | 648 | |
33165ec3 BN |
649 | if (!cache->flush) |
650 | return; | |
2556c98b | 651 | |
33165ec3 BN |
652 | for (i = 0; i < cache->c_hashsize; i++) { |
653 | hash = &cache->c_hash[i]; | |
2556c98b | 654 | |
33165ec3 BN |
655 | pthread_mutex_lock(&hash->ch_mutex); |
656 | head = &hash->ch_list; | |
657 | for (pos = head->next; pos != head; pos = pos->next) { | |
658 | node = (struct cache_node *)pos; | |
659 | pthread_mutex_lock(&node->cn_mutex); | |
660 | cache->flush(node); | |
661 | pthread_mutex_unlock(&node->cn_mutex); | |
662 | } | |
663 | pthread_mutex_unlock(&hash->ch_mutex); | |
664 | } | |
e80aa729 | 665 | } |
9f38f08d | 666 | |
69ec88b5 | 667 | #define HASH_REPORT (3 * HASH_CACHE_RATIO) |
9f38f08d | 668 | void |
69ec88b5 | 669 | cache_report( |
aef29e17 DC |
670 | FILE *fp, |
671 | const char *name, | |
672 | struct cache *cache) | |
9f38f08d | 673 | { |
aef29e17 DC |
674 | int i; |
675 | unsigned long count, index, total; | |
676 | unsigned long hash_bucket_lengths[HASH_REPORT + 2]; | |
b6281496 | 677 | |
69ec88b5 | 678 | if ((cache->c_hits + cache->c_misses) == 0) |
b6281496 MV |
679 | return; |
680 | ||
681 | /* report cache summary */ | |
682 | fprintf(fp, "%s: %p\n" | |
9f38f08d MV |
683 | "Max supported entries = %u\n" |
684 | "Max utilized entries = %u\n" | |
685 | "Active entries = %u\n" | |
686 | "Hash table size = %u\n" | |
687 | "Hits = %llu\n" | |
688 | "Misses = %llu\n" | |
689 | "Hit ratio = %5.2f\n", | |
690 | name, cache, | |
691 | cache->c_maxcount, | |
692 | cache->c_max, | |
693 | cache->c_count, | |
694 | cache->c_hashsize, | |
695 | cache->c_hits, | |
696 | cache->c_misses, | |
69ec88b5 BN |
697 | (double)cache->c_hits * 100 / |
698 | (cache->c_hits + cache->c_misses) | |
9f38f08d | 699 | ); |
b6281496 | 700 | |
69ec88b5 BN |
701 | for (i = 0; i <= CACHE_MAX_PRIORITY; i++) |
702 | fprintf(fp, "MRU %d entries = %6u (%3u%%)\n", | |
703 | i, cache->c_mrus[i].cm_count, | |
704 | cache->c_mrus[i].cm_count * 100 / cache->c_count); | |
705 | ||
aef29e17 DC |
706 | i = CACHE_DIRTY_PRIORITY; |
707 | fprintf(fp, "Dirty MRU %d entries = %6u (%3u%%)\n", | |
708 | i, cache->c_mrus[i].cm_count, | |
709 | cache->c_mrus[i].cm_count * 100 / cache->c_count); | |
710 | ||
b6281496 MV |
711 | /* report hash bucket lengths */ |
712 | bzero(hash_bucket_lengths, sizeof(hash_bucket_lengths)); | |
713 | ||
714 | for (i = 0; i < cache->c_hashsize; i++) { | |
715 | count = cache->c_hash[i].ch_count; | |
716 | if (count > HASH_REPORT) | |
717 | index = HASH_REPORT + 1; | |
718 | else | |
719 | index = count; | |
720 | hash_bucket_lengths[index]++; | |
721 | } | |
722 | ||
723 | total = 0; | |
69ec88b5 BN |
724 | for (i = 0; i < HASH_REPORT + 1; i++) { |
725 | total += i * hash_bucket_lengths[i]; | |
b6281496 MV |
726 | if (hash_bucket_lengths[i] == 0) |
727 | continue; | |
69ec88b5 BN |
728 | fprintf(fp, "Hash buckets with %2d entries %6ld (%3ld%%)\n", |
729 | i, hash_bucket_lengths[i], | |
730 | (i * hash_bucket_lengths[i] * 100) / cache->c_count); | |
b6281496 MV |
731 | } |
732 | if (hash_bucket_lengths[i]) /* last report bucket is the overflow bucket */ | |
69ec88b5 BN |
733 | fprintf(fp, "Hash buckets with >%2d entries %6ld (%3ld%%)\n", |
734 | i - 1, hash_bucket_lengths[i], | |
735 | ((cache->c_count - total) * 100) / cache->c_count); | |
9f38f08d | 736 | } |