Blame view
block/elevator.c
25.6 KB
1da177e4c Linux-2.6.12-rc2 |
1 |
/* |
1da177e4c Linux-2.6.12-rc2 |
2 3 4 5 |
* Block device elevator/IO-scheduler. * * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE * |
0fe234795 [PATCH] Update ax... |
6 |
* 30042000 Jens Axboe <axboe@kernel.dk> : |
1da177e4c Linux-2.6.12-rc2 |
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 |
* * Split the elevator a bit so that it is possible to choose a different * one or even write a new "plug in". There are three pieces: * - elevator_fn, inserts a new request in the queue list * - elevator_merge_fn, decides whether a new buffer can be merged with * an existing request * - elevator_dequeue_fn, called when a request is taken off the active list * * 20082000 Dave Jones <davej@suse.de> : * Removed tests for max-bomb-segments, which was breaking elvtune * when run without -bN * * Jens: * - Rework again to work with bio instead of buffer_heads * - loose bi_dev comparisons, partition handling is right now * - completely modularize elevator setup and teardown * */ #include <linux/kernel.h> #include <linux/fs.h> #include <linux/blkdev.h> #include <linux/elevator.h> #include <linux/bio.h> |
1da177e4c Linux-2.6.12-rc2 |
30 31 32 33 |
#include <linux/module.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/compiler.h> |
cb98fc8bb [BLOCK] Reimpleme... |
34 |
#include <linux/delay.h> |
2056a782f [PATCH] Block que... |
35 |
#include <linux/blktrace_api.h> |
9817064b6 [PATCH] elevator:... |
36 |
#include <linux/hash.h> |
1da177e4c Linux-2.6.12-rc2 |
37 38 39 40 41 42 43 |
#include <asm/uaccess.h> static DEFINE_SPINLOCK(elv_list_lock); static LIST_HEAD(elv_list); /* |
9817064b6 [PATCH] elevator:... |
44 45 46 47 |
* Merge hash stuff. */ static const int elv_hash_shift = 6; #define ELV_HASH_BLOCK(sec) ((sec) >> 3) |
4eb166d98 block: make eleva... |
48 49 |
#define ELV_HASH_FN(sec) \ (hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift)) |
9817064b6 [PATCH] elevator:... |
50 51 52 53 54 |
#define ELV_HASH_ENTRIES (1 << elv_hash_shift) #define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors) #define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) /* |
da7752650 [PATCH] cfq-iosch... |
55 56 57 58 59 |
* Query io scheduler to see if the current process issuing bio may be * merged with rq. */ static int elv_iosched_allow_merge(struct request *rq, struct bio *bio) { |
165125e1e [BLOCK] Get rid o... |
60 |
struct request_queue *q = rq->q; |
da7752650 [PATCH] cfq-iosch... |
61 62 63 64 65 66 67 68 69 |
elevator_t *e = q->elevator; if (e->ops->elevator_allow_merge_fn) return e->ops->elevator_allow_merge_fn(q, rq, bio); return 1; } /* |
1da177e4c Linux-2.6.12-rc2 |
70 71 72 73 74 75 76 77 78 79 80 81 82 83 |
* can we safely merge with this request? */ inline int elv_rq_merge_ok(struct request *rq, struct bio *bio) { if (!rq_mergeable(rq)) return 0; /* * different data direction or already started, don't merge */ if (bio_data_dir(bio) != rq_data_dir(rq)) return 0; /* |
da7752650 [PATCH] cfq-iosch... |
84 |
* must be same device and not a special request |
1da177e4c Linux-2.6.12-rc2 |
85 |
*/ |
bb4067e34 [PATCH] elevator:... |
86 |
if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special) |
da7752650 [PATCH] cfq-iosch... |
87 88 89 90 |
return 0; if (!elv_iosched_allow_merge(rq, bio)) return 0; |
1da177e4c Linux-2.6.12-rc2 |
91 |
|
da7752650 [PATCH] cfq-iosch... |
92 |
return 1; |
1da177e4c Linux-2.6.12-rc2 |
93 94 |
} EXPORT_SYMBOL(elv_rq_merge_ok); |
769db45b7 make elv_try_merg... |
95 |
static inline int elv_try_merge(struct request *__rq, struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 |
{ int ret = ELEVATOR_NO_MERGE; /* * we can merge and sequence is ok, check if it's possible */ if (elv_rq_merge_ok(__rq, bio)) { if (__rq->sector + __rq->nr_sectors == bio->bi_sector) ret = ELEVATOR_BACK_MERGE; else if (__rq->sector - bio_sectors(bio) == bio->bi_sector) ret = ELEVATOR_FRONT_MERGE; } return ret; } |
1da177e4c Linux-2.6.12-rc2 |
111 |
|
1da177e4c Linux-2.6.12-rc2 |
112 113 |
static struct elevator_type *elevator_find(const char *name) { |
a22b169df [PATCH] block lay... |
114 |
struct elevator_type *e; |
1da177e4c Linux-2.6.12-rc2 |
115 |
|
70cee26e0 Use list_for_each... |
116 |
list_for_each_entry(e, &elv_list, list) { |
a22b169df [PATCH] block lay... |
117 118 |
if (!strcmp(e->elevator_name, name)) return e; |
1da177e4c Linux-2.6.12-rc2 |
119 |
} |
1da177e4c Linux-2.6.12-rc2 |
120 |
|
a22b169df [PATCH] block lay... |
121 |
return NULL; |
1da177e4c Linux-2.6.12-rc2 |
122 123 124 125 126 127 128 129 130 |
} static void elevator_put(struct elevator_type *e) { module_put(e->elevator_owner); } static struct elevator_type *elevator_get(const char *name) { |
2824bc932 [PATCH] fix try_m... |
131 |
struct elevator_type *e; |
1da177e4c Linux-2.6.12-rc2 |
132 |
|
2a12dcd71 [PATCH] elevator:... |
133 |
spin_lock(&elv_list_lock); |
2824bc932 [PATCH] fix try_m... |
134 135 136 137 |
e = elevator_find(name); if (e && !try_module_get(e->elevator_owner)) e = NULL; |
2a12dcd71 [PATCH] elevator:... |
138 |
spin_unlock(&elv_list_lock); |
1da177e4c Linux-2.6.12-rc2 |
139 140 141 |
return e; } |
165125e1e [BLOCK] Get rid o... |
142 143 |
static void *elevator_init_queue(struct request_queue *q, struct elevator_queue *eq) |
1da177e4c Linux-2.6.12-rc2 |
144 |
{ |
bb37b94c6 [BLOCK] Cleanup u... |
145 |
return eq->ops->elevator_init_fn(q); |
bc1c11697 [PATCH] elevator ... |
146 |
} |
1da177e4c Linux-2.6.12-rc2 |
147 |
|
165125e1e [BLOCK] Get rid o... |
148 |
static void elevator_attach(struct request_queue *q, struct elevator_queue *eq, |
bc1c11697 [PATCH] elevator ... |
149 150 |
void *data) { |
1da177e4c Linux-2.6.12-rc2 |
151 |
q->elevator = eq; |
bc1c11697 [PATCH] elevator ... |
152 |
eq->elevator_data = data; |
1da177e4c Linux-2.6.12-rc2 |
153 154 155 |
} static char chosen_elevator[16]; |
5f0039764 [BLOCK] elevator:... |
156 |
static int __init elevator_setup(char *str) |
1da177e4c Linux-2.6.12-rc2 |
157 |
{ |
752a3b796 [BLOCK] elevator:... |
158 159 160 161 |
/* * Be backwards-compatible with previous kernels, so users * won't get the wrong elevator. */ |
5f0039764 [BLOCK] elevator:... |
162 |
if (!strcmp(str, "as")) |
752a3b796 [BLOCK] elevator:... |
163 |
strcpy(chosen_elevator, "anticipatory"); |
cff3ba220 [BLOCK] elevator ... |
164 |
else |
5f0039764 [BLOCK] elevator:... |
165 |
strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1); |
9b41046cd [PATCH] Don't pas... |
166 |
return 1; |
1da177e4c Linux-2.6.12-rc2 |
167 168 169 |
} __setup("elevator=", elevator_setup); |
3d1ab40f4 [PATCH] elevator_... |
170 |
static struct kobj_type elv_ktype; |
165125e1e [BLOCK] Get rid o... |
171 172 |
static elevator_t *elevator_alloc(struct request_queue *q, struct elevator_type *e) |
3d1ab40f4 [PATCH] elevator_... |
173 |
{ |
9817064b6 [PATCH] elevator:... |
174 175 |
elevator_t *eq; int i; |
94f6030ca Slab allocators: ... |
176 |
eq = kmalloc_node(sizeof(elevator_t), GFP_KERNEL | __GFP_ZERO, q->node); |
9817064b6 [PATCH] elevator:... |
177 178 |
if (unlikely(!eq)) goto err; |
9817064b6 [PATCH] elevator:... |
179 180 |
eq->ops = &e->ops; eq->elevator_type = e; |
f9cb074bf Kobject: rename k... |
181 |
kobject_init(&eq->kobj, &elv_ktype); |
9817064b6 [PATCH] elevator:... |
182 |
mutex_init(&eq->sysfs_lock); |
b5deef901 [PATCH] Make sure... |
183 184 |
eq->hash = kmalloc_node(sizeof(struct hlist_head) * ELV_HASH_ENTRIES, GFP_KERNEL, q->node); |
9817064b6 [PATCH] elevator:... |
185 186 187 188 189 |
if (!eq->hash) goto err; for (i = 0; i < ELV_HASH_ENTRIES; i++) INIT_HLIST_HEAD(&eq->hash[i]); |
3d1ab40f4 [PATCH] elevator_... |
190 |
return eq; |
9817064b6 [PATCH] elevator:... |
191 192 193 194 |
err: kfree(eq); elevator_put(e); return NULL; |
3d1ab40f4 [PATCH] elevator_... |
195 196 197 198 199 |
} static void elevator_release(struct kobject *kobj) { elevator_t *e = container_of(kobj, elevator_t, kobj); |
9817064b6 [PATCH] elevator:... |
200 |
|
3d1ab40f4 [PATCH] elevator_... |
201 |
elevator_put(e->elevator_type); |
9817064b6 [PATCH] elevator:... |
202 |
kfree(e->hash); |
3d1ab40f4 [PATCH] elevator_... |
203 204 |
kfree(e); } |
165125e1e [BLOCK] Get rid o... |
205 |
int elevator_init(struct request_queue *q, char *name) |
1da177e4c Linux-2.6.12-rc2 |
206 207 208 209 |
{ struct elevator_type *e = NULL; struct elevator_queue *eq; int ret = 0; |
bc1c11697 [PATCH] elevator ... |
210 |
void *data; |
1da177e4c Linux-2.6.12-rc2 |
211 |
|
cb98fc8bb [BLOCK] Reimpleme... |
212 213 214 215 |
INIT_LIST_HEAD(&q->queue_head); q->last_merge = NULL; q->end_sector = 0; q->boundary_rq = NULL; |
cb98fc8bb [BLOCK] Reimpleme... |
216 |
|
4eb166d98 block: make eleva... |
217 218 219 220 221 |
if (name) { e = elevator_get(name); if (!e) return -EINVAL; } |
1da177e4c Linux-2.6.12-rc2 |
222 |
|
4eb166d98 block: make eleva... |
223 224 225 226 227 228 229 |
if (!e && *chosen_elevator) { e = elevator_get(chosen_elevator); if (!e) printk(KERN_ERR "I/O scheduler %s not found ", chosen_elevator); } |
248d5ca5e [BLOCK] elevator:... |
230 |
|
4eb166d98 block: make eleva... |
231 232 233 234 235 236 237 238 239 |
if (!e) { e = elevator_get(CONFIG_DEFAULT_IOSCHED); if (!e) { printk(KERN_ERR "Default I/O scheduler not found. " \ "Using noop. "); e = elevator_get("noop"); } |
5f0039764 [BLOCK] elevator:... |
240 |
} |
b5deef901 [PATCH] Make sure... |
241 |
eq = elevator_alloc(q, e); |
3d1ab40f4 [PATCH] elevator_... |
242 |
if (!eq) |
1da177e4c Linux-2.6.12-rc2 |
243 |
return -ENOMEM; |
1da177e4c Linux-2.6.12-rc2 |
244 |
|
bc1c11697 [PATCH] elevator ... |
245 246 |
data = elevator_init_queue(q, eq); if (!data) { |
3d1ab40f4 [PATCH] elevator_... |
247 |
kobject_put(&eq->kobj); |
bc1c11697 [PATCH] elevator ... |
248 249 |
return -ENOMEM; } |
1da177e4c Linux-2.6.12-rc2 |
250 |
|
bc1c11697 [PATCH] elevator ... |
251 |
elevator_attach(q, eq, data); |
1da177e4c Linux-2.6.12-rc2 |
252 253 |
return ret; } |
2e662b65f [PATCH] elevator:... |
254 |
EXPORT_SYMBOL(elevator_init); |
1da177e4c Linux-2.6.12-rc2 |
255 256 |
void elevator_exit(elevator_t *e) { |
3d1ab40f4 [PATCH] elevator_... |
257 |
mutex_lock(&e->sysfs_lock); |
1da177e4c Linux-2.6.12-rc2 |
258 259 |
if (e->ops->elevator_exit_fn) e->ops->elevator_exit_fn(e); |
3d1ab40f4 [PATCH] elevator_... |
260 261 |
e->ops = NULL; mutex_unlock(&e->sysfs_lock); |
1da177e4c Linux-2.6.12-rc2 |
262 |
|
3d1ab40f4 [PATCH] elevator_... |
263 |
kobject_put(&e->kobj); |
1da177e4c Linux-2.6.12-rc2 |
264 |
} |
2e662b65f [PATCH] elevator:... |
265 |
EXPORT_SYMBOL(elevator_exit); |
165125e1e [BLOCK] Get rid o... |
266 |
static void elv_activate_rq(struct request_queue *q, struct request *rq) |
cad975164 elevator: abstrac... |
267 268 269 270 271 272 |
{ elevator_t *e = q->elevator; if (e->ops->elevator_activate_req_fn) e->ops->elevator_activate_req_fn(q, rq); } |
165125e1e [BLOCK] Get rid o... |
273 |
static void elv_deactivate_rq(struct request_queue *q, struct request *rq) |
cad975164 elevator: abstrac... |
274 275 276 277 278 279 |
{ elevator_t *e = q->elevator; if (e->ops->elevator_deactivate_req_fn) e->ops->elevator_deactivate_req_fn(q, rq); } |
9817064b6 [PATCH] elevator:... |
280 281 282 283 |
static inline void __elv_rqhash_del(struct request *rq) { hlist_del_init(&rq->hash); } |
165125e1e [BLOCK] Get rid o... |
284 |
static void elv_rqhash_del(struct request_queue *q, struct request *rq) |
9817064b6 [PATCH] elevator:... |
285 286 287 288 |
{ if (ELV_ON_HASH(rq)) __elv_rqhash_del(rq); } |
165125e1e [BLOCK] Get rid o... |
289 |
static void elv_rqhash_add(struct request_queue *q, struct request *rq) |
9817064b6 [PATCH] elevator:... |
290 291 292 293 294 295 |
{ elevator_t *e = q->elevator; BUG_ON(ELV_ON_HASH(rq)); hlist_add_head(&rq->hash, &e->hash[ELV_HASH_FN(rq_hash_key(rq))]); } |
165125e1e [BLOCK] Get rid o... |
296 |
static void elv_rqhash_reposition(struct request_queue *q, struct request *rq) |
9817064b6 [PATCH] elevator:... |
297 298 299 300 |
{ __elv_rqhash_del(rq); elv_rqhash_add(q, rq); } |
165125e1e [BLOCK] Get rid o... |
301 |
static struct request *elv_rqhash_find(struct request_queue *q, sector_t offset) |
9817064b6 [PATCH] elevator:... |
302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 |
{ elevator_t *e = q->elevator; struct hlist_head *hash_list = &e->hash[ELV_HASH_FN(offset)]; struct hlist_node *entry, *next; struct request *rq; hlist_for_each_entry_safe(rq, entry, next, hash_list, hash) { BUG_ON(!ELV_ON_HASH(rq)); if (unlikely(!rq_mergeable(rq))) { __elv_rqhash_del(rq); continue; } if (rq_hash_key(rq) == offset) return rq; } return NULL; } |
8922e16cf [PATCH] 01/05 Imp... |
322 |
/* |
2e662b65f [PATCH] elevator:... |
323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 |
* RB-tree support functions for inserting/lookup/removal of requests * in a sorted RB tree. */ struct request *elv_rb_add(struct rb_root *root, struct request *rq) { struct rb_node **p = &root->rb_node; struct rb_node *parent = NULL; struct request *__rq; while (*p) { parent = *p; __rq = rb_entry(parent, struct request, rb_node); if (rq->sector < __rq->sector) p = &(*p)->rb_left; else if (rq->sector > __rq->sector) p = &(*p)->rb_right; else return __rq; } rb_link_node(&rq->rb_node, parent, p); rb_insert_color(&rq->rb_node, root); return NULL; } |
2e662b65f [PATCH] elevator:... |
348 349 350 351 352 353 354 355 |
EXPORT_SYMBOL(elv_rb_add); void elv_rb_del(struct rb_root *root, struct request *rq) { BUG_ON(RB_EMPTY_NODE(&rq->rb_node)); rb_erase(&rq->rb_node, root); RB_CLEAR_NODE(&rq->rb_node); } |
2e662b65f [PATCH] elevator:... |
356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 |
EXPORT_SYMBOL(elv_rb_del); struct request *elv_rb_find(struct rb_root *root, sector_t sector) { struct rb_node *n = root->rb_node; struct request *rq; while (n) { rq = rb_entry(n, struct request, rb_node); if (sector < rq->sector) n = n->rb_left; else if (sector > rq->sector) n = n->rb_right; else return rq; } return NULL; } |
2e662b65f [PATCH] elevator:... |
376 377 378 |
EXPORT_SYMBOL(elv_rb_find); /* |
8922e16cf [PATCH] 01/05 Imp... |
379 |
* Insert rq into dispatch queue of q. Queue lock must be held on |
dbe7f76dd fix typo "insted"... |
380 |
* entry. rq is sort instead into the dispatch queue. To be used by |
2e662b65f [PATCH] elevator:... |
381 |
* specific elevators. |
8922e16cf [PATCH] 01/05 Imp... |
382 |
*/ |
165125e1e [BLOCK] Get rid o... |
383 |
void elv_dispatch_sort(struct request_queue *q, struct request *rq) |
8922e16cf [PATCH] 01/05 Imp... |
384 385 |
{ sector_t boundary; |
8922e16cf [PATCH] 01/05 Imp... |
386 |
struct list_head *entry; |
4eb166d98 block: make eleva... |
387 |
int stop_flags; |
8922e16cf [PATCH] 01/05 Imp... |
388 |
|
06b86245c [PATCH] 03/05 mov... |
389 390 |
if (q->last_merge == rq) q->last_merge = NULL; |
9817064b6 [PATCH] elevator:... |
391 392 |
elv_rqhash_del(q, rq); |
15853af9f [BLOCK] Implement... |
393 |
q->nr_sorted--; |
06b86245c [PATCH] 03/05 mov... |
394 |
|
1b47f531e [PATCH] generic d... |
395 |
boundary = q->end_sector; |
4eb166d98 block: make eleva... |
396 |
stop_flags = REQ_SOFTBARRIER | REQ_HARDBARRIER | REQ_STARTED; |
8922e16cf [PATCH] 01/05 Imp... |
397 398 |
list_for_each_prev(entry, &q->queue_head) { struct request *pos = list_entry_rq(entry); |
783660b2f elevator: don't s... |
399 400 |
if (rq_data_dir(rq) != rq_data_dir(pos)) break; |
4eb166d98 block: make eleva... |
401 |
if (pos->cmd_flags & stop_flags) |
8922e16cf [PATCH] 01/05 Imp... |
402 403 404 405 406 407 408 409 410 411 412 413 414 415 |
break; if (rq->sector >= boundary) { if (pos->sector < boundary) continue; } else { if (pos->sector >= boundary) break; } if (rq->sector >= pos->sector) break; } list_add(&rq->queuelist, entry); } |
2e662b65f [PATCH] elevator:... |
416 |
EXPORT_SYMBOL(elv_dispatch_sort); |
9817064b6 [PATCH] elevator:... |
417 |
/* |
2e662b65f [PATCH] elevator:... |
418 419 420 |
* Insert rq into dispatch queue of q. Queue lock must be held on * entry. rq is added to the back of the dispatch queue. To be used by * specific elevators. |
9817064b6 [PATCH] elevator:... |
421 422 423 424 425 426 427 428 429 430 431 432 433 434 |
*/ void elv_dispatch_add_tail(struct request_queue *q, struct request *rq) { if (q->last_merge == rq) q->last_merge = NULL; elv_rqhash_del(q, rq); q->nr_sorted--; q->end_sector = rq_end_sector(rq); q->boundary_rq = rq; list_add_tail(&rq->queuelist, &q->queue_head); } |
2e662b65f [PATCH] elevator:... |
435 |
EXPORT_SYMBOL(elv_dispatch_add_tail); |
165125e1e [BLOCK] Get rid o... |
436 |
int elv_merge(struct request_queue *q, struct request **req, struct bio *bio) |
1da177e4c Linux-2.6.12-rc2 |
437 438 |
{ elevator_t *e = q->elevator; |
9817064b6 [PATCH] elevator:... |
439 |
struct request *__rq; |
06b86245c [PATCH] 03/05 mov... |
440 |
int ret; |
9817064b6 [PATCH] elevator:... |
441 442 443 |
/* * First try one-hit cache. */ |
06b86245c [PATCH] 03/05 mov... |
444 445 446 447 448 449 450 |
if (q->last_merge) { ret = elv_try_merge(q->last_merge, bio); if (ret != ELEVATOR_NO_MERGE) { *req = q->last_merge; return ret; } } |
1da177e4c Linux-2.6.12-rc2 |
451 |
|
9817064b6 [PATCH] elevator:... |
452 453 454 455 456 457 458 459 |
/* * See if our hash lookup can find a potential backmerge. */ __rq = elv_rqhash_find(q, bio->bi_sector); if (__rq && elv_rq_merge_ok(__rq, bio)) { *req = __rq; return ELEVATOR_BACK_MERGE; } |
1da177e4c Linux-2.6.12-rc2 |
460 461 462 463 464 |
if (e->ops->elevator_merge_fn) return e->ops->elevator_merge_fn(q, req, bio); return ELEVATOR_NO_MERGE; } |
165125e1e [BLOCK] Get rid o... |
465 |
void elv_merged_request(struct request_queue *q, struct request *rq, int type) |
1da177e4c Linux-2.6.12-rc2 |
466 467 468 469 |
{ elevator_t *e = q->elevator; if (e->ops->elevator_merged_fn) |
2e662b65f [PATCH] elevator:... |
470 |
e->ops->elevator_merged_fn(q, rq, type); |
06b86245c [PATCH] 03/05 mov... |
471 |
|
2e662b65f [PATCH] elevator:... |
472 473 |
if (type == ELEVATOR_BACK_MERGE) elv_rqhash_reposition(q, rq); |
9817064b6 [PATCH] elevator:... |
474 |
|
06b86245c [PATCH] 03/05 mov... |
475 |
q->last_merge = rq; |
1da177e4c Linux-2.6.12-rc2 |
476 |
} |
165125e1e [BLOCK] Get rid o... |
477 |
void elv_merge_requests(struct request_queue *q, struct request *rq, |
1da177e4c Linux-2.6.12-rc2 |
478 479 480 |
struct request *next) { elevator_t *e = q->elevator; |
1da177e4c Linux-2.6.12-rc2 |
481 482 |
if (e->ops->elevator_merge_req_fn) e->ops->elevator_merge_req_fn(q, rq, next); |
06b86245c [PATCH] 03/05 mov... |
483 |
|
9817064b6 [PATCH] elevator:... |
484 485 486 487 |
elv_rqhash_reposition(q, rq); elv_rqhash_del(q, next); q->nr_sorted--; |
06b86245c [PATCH] 03/05 mov... |
488 |
q->last_merge = rq; |
1da177e4c Linux-2.6.12-rc2 |
489 |
} |
165125e1e [BLOCK] Get rid o... |
490 |
void elv_requeue_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
491 |
{ |
1da177e4c Linux-2.6.12-rc2 |
492 493 494 495 |
/* * it already went through dequeue, we need to decrement the * in_flight count again */ |
8922e16cf [PATCH] 01/05 Imp... |
496 |
if (blk_account_rq(rq)) { |
1da177e4c Linux-2.6.12-rc2 |
497 |
q->in_flight--; |
cad975164 elevator: abstrac... |
498 499 |
if (blk_sorted_rq(rq)) elv_deactivate_rq(q, rq); |
8922e16cf [PATCH] 01/05 Imp... |
500 |
} |
1da177e4c Linux-2.6.12-rc2 |
501 |
|
4aff5e233 [PATCH] Split str... |
502 |
rq->cmd_flags &= ~REQ_STARTED; |
1da177e4c Linux-2.6.12-rc2 |
503 |
|
30e9656cc [PATCH] block: im... |
504 |
elv_insert(q, rq, ELEVATOR_INSERT_REQUEUE); |
1da177e4c Linux-2.6.12-rc2 |
505 |
} |
165125e1e [BLOCK] Get rid o... |
506 |
static void elv_drain_elevator(struct request_queue *q) |
15853af9f [BLOCK] Implement... |
507 508 509 510 511 512 513 514 515 516 517 518 519 |
{ static int printed; while (q->elevator->ops->elevator_dispatch_fn(q, 1)) ; if (q->nr_sorted == 0) return; if (printed++ < 10) { printk(KERN_ERR "%s: forced dispatching is broken " "(nr_sorted=%u), please report this ", q->elevator->elevator_type->elevator_name, q->nr_sorted); } } |
165125e1e [BLOCK] Get rid o... |
520 |
void elv_insert(struct request_queue *q, struct request *rq, int where) |
1da177e4c Linux-2.6.12-rc2 |
521 |
{ |
797e7dbbe [BLOCK] reimpleme... |
522 523 |
struct list_head *pos; unsigned ordseq; |
dac07ec12 [BLOCK] limit req... |
524 |
int unplug_it = 1; |
797e7dbbe [BLOCK] reimpleme... |
525 |
|
2056a782f [PATCH] Block que... |
526 |
blk_add_trace_rq(q, rq, BLK_TA_INSERT); |
1da177e4c Linux-2.6.12-rc2 |
527 |
rq->q = q; |
8922e16cf [PATCH] 01/05 Imp... |
528 529 |
switch (where) { case ELEVATOR_INSERT_FRONT: |
4aff5e233 [PATCH] Split str... |
530 |
rq->cmd_flags |= REQ_SOFTBARRIER; |
8922e16cf [PATCH] 01/05 Imp... |
531 532 533 534 535 |
list_add(&rq->queuelist, &q->queue_head); break; case ELEVATOR_INSERT_BACK: |
4aff5e233 [PATCH] Split str... |
536 |
rq->cmd_flags |= REQ_SOFTBARRIER; |
15853af9f [BLOCK] Implement... |
537 |
elv_drain_elevator(q); |
8922e16cf [PATCH] 01/05 Imp... |
538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 |
list_add_tail(&rq->queuelist, &q->queue_head); /* * We kick the queue here for the following reasons. * - The elevator might have returned NULL previously * to delay requests and returned them now. As the * queue wasn't empty before this request, ll_rw_blk * won't run the queue on return, resulting in hang. * - Usually, back inserted requests won't be merged * with anything. There's no point in delaying queue * processing. */ blk_remove_plug(q); q->request_fn(q); break; case ELEVATOR_INSERT_SORT: BUG_ON(!blk_fs_request(rq)); |
4aff5e233 [PATCH] Split str... |
555 |
rq->cmd_flags |= REQ_SORTED; |
15853af9f [BLOCK] Implement... |
556 |
q->nr_sorted++; |
9817064b6 [PATCH] elevator:... |
557 558 559 560 561 |
if (rq_mergeable(rq)) { elv_rqhash_add(q, rq); if (!q->last_merge) q->last_merge = rq; } |
ca23509fb [PATCH] blk: fix ... |
562 563 564 565 566 567 |
/* * Some ioscheds (cfq) run q->request_fn directly, so * rq cannot be accessed after calling * elevator_add_req_fn. */ q->elevator->ops->elevator_add_req_fn(q, rq); |
8922e16cf [PATCH] 01/05 Imp... |
568 |
break; |
797e7dbbe [BLOCK] reimpleme... |
569 570 571 572 573 574 |
case ELEVATOR_INSERT_REQUEUE: /* * If ordered flush isn't in progress, we do front * insertion; otherwise, requests should be requeued * in ordseq order. */ |
4aff5e233 [PATCH] Split str... |
575 |
rq->cmd_flags |= REQ_SOFTBARRIER; |
797e7dbbe [BLOCK] reimpleme... |
576 |
|
95543179f [PATCH] elevator:... |
577 578 579 580 581 |
/* * Most requeues happen because of a busy condition, * don't force unplug of the queue for that case. */ unplug_it = 0; |
797e7dbbe [BLOCK] reimpleme... |
582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 |
if (q->ordseq == 0) { list_add(&rq->queuelist, &q->queue_head); break; } ordseq = blk_ordered_req_seq(rq); list_for_each(pos, &q->queue_head) { struct request *pos_rq = list_entry_rq(pos); if (ordseq <= blk_ordered_req_seq(pos_rq)) break; } list_add_tail(&rq->queuelist, pos); break; |
8922e16cf [PATCH] 01/05 Imp... |
597 598 599 600 601 602 |
default: printk(KERN_ERR "%s: bad insertion point %d ", __FUNCTION__, where); BUG(); } |
dac07ec12 [BLOCK] limit req... |
603 |
if (unplug_it && blk_queue_plugged(q)) { |
8922e16cf [PATCH] 01/05 Imp... |
604 605 606 607 608 609 |
int nrq = q->rq.count[READ] + q->rq.count[WRITE] - q->in_flight; if (nrq >= q->unplug_thresh) __generic_unplug_device(q); } |
1da177e4c Linux-2.6.12-rc2 |
610 |
} |
165125e1e [BLOCK] Get rid o... |
611 |
void __elv_add_request(struct request_queue *q, struct request *rq, int where, |
30e9656cc [PATCH] block: im... |
612 613 614 |
int plug) { if (q->ordcolor) |
4aff5e233 [PATCH] Split str... |
615 |
rq->cmd_flags |= REQ_ORDERED_COLOR; |
30e9656cc [PATCH] block: im... |
616 |
|
4aff5e233 [PATCH] Split str... |
617 |
if (rq->cmd_flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) { |
30e9656cc [PATCH] block: im... |
618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 |
/* * toggle ordered color */ if (blk_barrier_rq(rq)) q->ordcolor ^= 1; /* * barriers implicitly indicate back insertion */ if (where == ELEVATOR_INSERT_SORT) where = ELEVATOR_INSERT_BACK; /* * this request is scheduling boundary, update * end_sector */ if (blk_fs_request(rq)) { q->end_sector = rq_end_sector(rq); q->boundary_rq = rq; } |
4eb166d98 block: make eleva... |
638 639 |
} else if (!(rq->cmd_flags & REQ_ELVPRIV) && where == ELEVATOR_INSERT_SORT) |
30e9656cc [PATCH] block: im... |
640 641 642 643 644 645 646 |
where = ELEVATOR_INSERT_BACK; if (plug) blk_plug_device(q); elv_insert(q, rq, where); } |
2e662b65f [PATCH] elevator:... |
647 |
EXPORT_SYMBOL(__elv_add_request); |
165125e1e [BLOCK] Get rid o... |
648 |
void elv_add_request(struct request_queue *q, struct request *rq, int where, |
1da177e4c Linux-2.6.12-rc2 |
649 650 651 652 653 654 655 656 |
int plug) { unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); __elv_add_request(q, rq, where, plug); spin_unlock_irqrestore(q->queue_lock, flags); } |
2e662b65f [PATCH] elevator:... |
657 |
EXPORT_SYMBOL(elv_add_request); |
165125e1e [BLOCK] Get rid o... |
658 |
static inline struct request *__elv_next_request(struct request_queue *q) |
1da177e4c Linux-2.6.12-rc2 |
659 |
{ |
8922e16cf [PATCH] 01/05 Imp... |
660 |
struct request *rq; |
797e7dbbe [BLOCK] reimpleme... |
661 662 663 664 665 666 |
while (1) { while (!list_empty(&q->queue_head)) { rq = list_entry_rq(q->queue_head.next); if (blk_do_ordered(q, &rq)) return rq; } |
1da177e4c Linux-2.6.12-rc2 |
667 |
|
797e7dbbe [BLOCK] reimpleme... |
668 669 |
if (!q->elevator->ops->elevator_dispatch_fn(q, 0)) return NULL; |
1da177e4c Linux-2.6.12-rc2 |
670 |
} |
1da177e4c Linux-2.6.12-rc2 |
671 |
} |
165125e1e [BLOCK] Get rid o... |
672 |
struct request *elv_next_request(struct request_queue *q) |
1da177e4c Linux-2.6.12-rc2 |
673 674 675 676 677 |
{ struct request *rq; int ret; while ((rq = __elv_next_request(q)) != NULL) { |
bf2de6f5a block: Initial su... |
678 679 680 681 682 683 684 685 |
/* * Kill the empty barrier place holder, the driver must * not ever see it. */ if (blk_empty_barrier(rq)) { end_queued_request(rq, 1); continue; } |
4aff5e233 [PATCH] Split str... |
686 |
if (!(rq->cmd_flags & REQ_STARTED)) { |
8922e16cf [PATCH] 01/05 Imp... |
687 688 689 690 691 |
/* * This is the first time the device driver * sees this request (possibly after * requeueing). Notify IO scheduler. */ |
cad975164 elevator: abstrac... |
692 693 |
if (blk_sorted_rq(rq)) elv_activate_rq(q, rq); |
1da177e4c Linux-2.6.12-rc2 |
694 |
|
8922e16cf [PATCH] 01/05 Imp... |
695 696 697 698 699 |
/* * just mark as started even if we don't start * it, a request that has been delayed should * not be passed by new incoming requests */ |
4aff5e233 [PATCH] Split str... |
700 |
rq->cmd_flags |= REQ_STARTED; |
2056a782f [PATCH] Block que... |
701 |
blk_add_trace_rq(q, rq, BLK_TA_ISSUE); |
8922e16cf [PATCH] 01/05 Imp... |
702 |
} |
1da177e4c Linux-2.6.12-rc2 |
703 |
|
8922e16cf [PATCH] 01/05 Imp... |
704 |
if (!q->boundary_rq || q->boundary_rq == rq) { |
1b47f531e [PATCH] generic d... |
705 |
q->end_sector = rq_end_sector(rq); |
8922e16cf [PATCH] 01/05 Imp... |
706 707 |
q->boundary_rq = NULL; } |
1da177e4c Linux-2.6.12-rc2 |
708 |
|
fa0ccd837 block: implement ... |
709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 |
if (rq->cmd_flags & REQ_DONTPREP) break; if (q->dma_drain_size && rq->data_len) { /* * make sure space for the drain appears we * know we can do this because max_hw_segments * has been adjusted to be one fewer than the * device can handle */ rq->nr_phys_segments++; rq->nr_hw_segments++; } if (!q->prep_rq_fn) |
1da177e4c Linux-2.6.12-rc2 |
724 725 726 727 728 729 |
break; ret = q->prep_rq_fn(q, rq); if (ret == BLKPREP_OK) { break; } else if (ret == BLKPREP_DEFER) { |
2e759cd4f [SCSI] make blk l... |
730 731 732 |
/* * the request may have been (partially) prepped. * we need to keep this request in the front to |
8922e16cf [PATCH] 01/05 Imp... |
733 734 |
* avoid resource deadlock. REQ_STARTED will * prevent other fs requests from passing this one. |
2e759cd4f [SCSI] make blk l... |
735 |
*/ |
fa0ccd837 block: implement ... |
736 737 738 739 740 741 742 743 744 |
if (q->dma_drain_size && rq->data_len && !(rq->cmd_flags & REQ_DONTPREP)) { /* * remove the space for the drain we added * so that we don't add it again */ --rq->nr_phys_segments; --rq->nr_hw_segments; } |
1da177e4c Linux-2.6.12-rc2 |
745 746 747 |
rq = NULL; break; } else if (ret == BLKPREP_KILL) { |
4aff5e233 [PATCH] Split str... |
748 |
rq->cmd_flags |= REQ_QUIET; |
a0cd12854 block: add end_qu... |
749 |
end_queued_request(rq, 0); |
1da177e4c Linux-2.6.12-rc2 |
750 751 752 753 754 755 756 757 758 759 |
} else { printk(KERN_ERR "%s: bad return=%d ", __FUNCTION__, ret); break; } } return rq; } |
2e662b65f [PATCH] elevator:... |
760 |
EXPORT_SYMBOL(elv_next_request); |
165125e1e [BLOCK] Get rid o... |
761 |
void elv_dequeue_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
762 |
{ |
8922e16cf [PATCH] 01/05 Imp... |
763 |
BUG_ON(list_empty(&rq->queuelist)); |
9817064b6 [PATCH] elevator:... |
764 |
BUG_ON(ELV_ON_HASH(rq)); |
8922e16cf [PATCH] 01/05 Imp... |
765 766 |
list_del_init(&rq->queuelist); |
1da177e4c Linux-2.6.12-rc2 |
767 768 769 770 |
/* * the time frame between a request being removed from the lists * and to it is freed is accounted as io that is in progress at |
8922e16cf [PATCH] 01/05 Imp... |
771 |
* the driver side. |
1da177e4c Linux-2.6.12-rc2 |
772 773 774 |
*/ if (blk_account_rq(rq)) q->in_flight++; |
1da177e4c Linux-2.6.12-rc2 |
775 |
} |
2e662b65f [PATCH] elevator:... |
776 |
EXPORT_SYMBOL(elv_dequeue_request); |
165125e1e [BLOCK] Get rid o... |
777 |
int elv_queue_empty(struct request_queue *q) |
1da177e4c Linux-2.6.12-rc2 |
778 779 |
{ elevator_t *e = q->elevator; |
8922e16cf [PATCH] 01/05 Imp... |
780 781 |
if (!list_empty(&q->queue_head)) return 0; |
1da177e4c Linux-2.6.12-rc2 |
782 783 |
if (e->ops->elevator_queue_empty_fn) return e->ops->elevator_queue_empty_fn(q); |
8922e16cf [PATCH] 01/05 Imp... |
784 |
return 1; |
1da177e4c Linux-2.6.12-rc2 |
785 |
} |
2e662b65f [PATCH] elevator:... |
786 |
EXPORT_SYMBOL(elv_queue_empty); |
165125e1e [BLOCK] Get rid o... |
787 |
struct request *elv_latter_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
788 |
{ |
1da177e4c Linux-2.6.12-rc2 |
789 790 791 792 |
elevator_t *e = q->elevator; if (e->ops->elevator_latter_req_fn) return e->ops->elevator_latter_req_fn(q, rq); |
1da177e4c Linux-2.6.12-rc2 |
793 794 |
return NULL; } |
165125e1e [BLOCK] Get rid o... |
795 |
struct request *elv_former_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
796 |
{ |
1da177e4c Linux-2.6.12-rc2 |
797 798 799 800 |
elevator_t *e = q->elevator; if (e->ops->elevator_former_req_fn) return e->ops->elevator_former_req_fn(q, rq); |
1da177e4c Linux-2.6.12-rc2 |
801 802 |
return NULL; } |
165125e1e [BLOCK] Get rid o... |
803 |
int elv_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) |
1da177e4c Linux-2.6.12-rc2 |
804 805 806 807 |
{ elevator_t *e = q->elevator; if (e->ops->elevator_set_req_fn) |
cb78b285c [PATCH] Drop usel... |
808 |
return e->ops->elevator_set_req_fn(q, rq, gfp_mask); |
1da177e4c Linux-2.6.12-rc2 |
809 810 811 812 |
rq->elevator_private = NULL; return 0; } |
165125e1e [BLOCK] Get rid o... |
813 |
void elv_put_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
814 815 816 817 |
{ elevator_t *e = q->elevator; if (e->ops->elevator_put_req_fn) |
bb37b94c6 [BLOCK] Cleanup u... |
818 |
e->ops->elevator_put_req_fn(rq); |
1da177e4c Linux-2.6.12-rc2 |
819 |
} |
165125e1e [BLOCK] Get rid o... |
820 |
int elv_may_queue(struct request_queue *q, int rw) |
1da177e4c Linux-2.6.12-rc2 |
821 822 823 824 |
{ elevator_t *e = q->elevator; if (e->ops->elevator_may_queue_fn) |
cb78b285c [PATCH] Drop usel... |
825 |
return e->ops->elevator_may_queue_fn(q, rw); |
1da177e4c Linux-2.6.12-rc2 |
826 827 828 |
return ELV_MQUEUE_MAY; } |
165125e1e [BLOCK] Get rid o... |
829 |
void elv_completed_request(struct request_queue *q, struct request *rq) |
1da177e4c Linux-2.6.12-rc2 |
830 831 832 833 834 835 |
{ elevator_t *e = q->elevator; /* * request is released from the driver, io must be done */ |
8922e16cf [PATCH] 01/05 Imp... |
836 |
if (blk_account_rq(rq)) { |
1da177e4c Linux-2.6.12-rc2 |
837 |
q->in_flight--; |
1bc691d35 [PATCH] fix queue... |
838 839 840 |
if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn) e->ops->elevator_completed_req_fn(q, rq); } |
797e7dbbe [BLOCK] reimpleme... |
841 |
|
1bc691d35 [PATCH] fix queue... |
842 843 844 845 846 847 848 |
/* * Check if the queue is waiting for fs requests to be * drained for flush sequence. */ if (unlikely(q->ordseq)) { struct request *first_rq = list_entry_rq(q->queue_head.next); if (q->in_flight == 0 && |
797e7dbbe [BLOCK] reimpleme... |
849 850 851 852 853 |
blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN && blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) { blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0); q->request_fn(q); } |
8922e16cf [PATCH] 01/05 Imp... |
854 |
} |
1da177e4c Linux-2.6.12-rc2 |
855 |
} |
3d1ab40f4 [PATCH] elevator_... |
856 857 858 859 |
#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr) static ssize_t elv_attr_show(struct kobject *kobj, struct attribute *attr, char *page) |
1da177e4c Linux-2.6.12-rc2 |
860 |
{ |
3d1ab40f4 [PATCH] elevator_... |
861 862 863 864 865 866 867 868 869 870 871 872 |
elevator_t *e = container_of(kobj, elevator_t, kobj); struct elv_fs_entry *entry = to_elv(attr); ssize_t error; if (!entry->show) return -EIO; mutex_lock(&e->sysfs_lock); error = e->ops ? entry->show(e, page) : -ENOENT; mutex_unlock(&e->sysfs_lock); return error; } |
1da177e4c Linux-2.6.12-rc2 |
873 |
|
3d1ab40f4 [PATCH] elevator_... |
874 875 876 877 878 879 880 |
static ssize_t elv_attr_store(struct kobject *kobj, struct attribute *attr, const char *page, size_t length) { elevator_t *e = container_of(kobj, elevator_t, kobj); struct elv_fs_entry *entry = to_elv(attr); ssize_t error; |
1da177e4c Linux-2.6.12-rc2 |
881 |
|
3d1ab40f4 [PATCH] elevator_... |
882 883 |
if (!entry->store) return -EIO; |
1da177e4c Linux-2.6.12-rc2 |
884 |
|
3d1ab40f4 [PATCH] elevator_... |
885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 |
mutex_lock(&e->sysfs_lock); error = e->ops ? entry->store(e, page, length) : -ENOENT; mutex_unlock(&e->sysfs_lock); return error; } static struct sysfs_ops elv_sysfs_ops = { .show = elv_attr_show, .store = elv_attr_store, }; static struct kobj_type elv_ktype = { .sysfs_ops = &elv_sysfs_ops, .release = elevator_release, }; int elv_register_queue(struct request_queue *q) { elevator_t *e = q->elevator; int error; |
b2d6db587 Kobject: rename k... |
905 |
error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched"); |
3d1ab40f4 [PATCH] elevator_... |
906 |
if (!error) { |
e572ec7e4 [PATCH] fix rmmod... |
907 |
struct elv_fs_entry *attr = e->elevator_type->elevator_attrs; |
3d1ab40f4 [PATCH] elevator_... |
908 |
if (attr) { |
e572ec7e4 [PATCH] fix rmmod... |
909 910 |
while (attr->attr.name) { if (sysfs_create_file(&e->kobj, &attr->attr)) |
3d1ab40f4 [PATCH] elevator_... |
911 |
break; |
e572ec7e4 [PATCH] fix rmmod... |
912 |
attr++; |
3d1ab40f4 [PATCH] elevator_... |
913 914 915 916 917 |
} } kobject_uevent(&e->kobj, KOBJ_ADD); } return error; |
1da177e4c Linux-2.6.12-rc2 |
918 |
} |
bc1c11697 [PATCH] elevator ... |
919 920 921 922 923 |
static void __elv_unregister_queue(elevator_t *e) { kobject_uevent(&e->kobj, KOBJ_REMOVE); kobject_del(&e->kobj); } |
1da177e4c Linux-2.6.12-rc2 |
924 925 |
void elv_unregister_queue(struct request_queue *q) { |
bc1c11697 [PATCH] elevator ... |
926 927 |
if (q) __elv_unregister_queue(q->elevator); |
1da177e4c Linux-2.6.12-rc2 |
928 |
} |
2fdd82bd8 block: let elv_re... |
929 |
void elv_register(struct elevator_type *e) |
1da177e4c Linux-2.6.12-rc2 |
930 |
{ |
1ffb96c58 make elv_register... |
931 |
char *def = ""; |
2a12dcd71 [PATCH] elevator:... |
932 933 |
spin_lock(&elv_list_lock); |
ce5244974 BUG_ON() Conversi... |
934 |
BUG_ON(elevator_find(e->elevator_name)); |
1da177e4c Linux-2.6.12-rc2 |
935 |
list_add_tail(&e->list, &elv_list); |
2a12dcd71 [PATCH] elevator:... |
936 |
spin_unlock(&elv_list_lock); |
1da177e4c Linux-2.6.12-rc2 |
937 |
|
5f0039764 [BLOCK] elevator:... |
938 939 940 |
if (!strcmp(e->elevator_name, chosen_elevator) || (!*chosen_elevator && !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED))) |
1ffb96c58 make elv_register... |
941 |
def = " (default)"; |
4eb166d98 block: make eleva... |
942 943 944 |
printk(KERN_INFO "io scheduler %s registered%s ", e->elevator_name, def); |
1da177e4c Linux-2.6.12-rc2 |
945 946 947 948 949 |
} EXPORT_SYMBOL_GPL(elv_register); void elv_unregister(struct elevator_type *e) { |
83521d3eb [PATCH] cfq-iosch... |
950 951 952 953 954 |
struct task_struct *g, *p; /* * Iterate every thread in the process to remove the io contexts. */ |
e17a9489b [PATCH] stop elv_... |
955 956 957 958 |
if (e->ops.trim) { read_lock(&tasklist_lock); do_each_thread(g, p) { task_lock(p); |
2d8f61316 elv_unregister: f... |
959 960 |
if (p->io_context) e->ops.trim(p->io_context); |
e17a9489b [PATCH] stop elv_... |
961 962 963 964 |
task_unlock(p); } while_each_thread(g, p); read_unlock(&tasklist_lock); } |
83521d3eb [PATCH] cfq-iosch... |
965 |
|
2a12dcd71 [PATCH] elevator:... |
966 |
spin_lock(&elv_list_lock); |
1da177e4c Linux-2.6.12-rc2 |
967 |
list_del_init(&e->list); |
2a12dcd71 [PATCH] elevator:... |
968 |
spin_unlock(&elv_list_lock); |
1da177e4c Linux-2.6.12-rc2 |
969 970 971 972 973 974 975 |
} EXPORT_SYMBOL_GPL(elv_unregister); /* * switch to new_e io scheduler. be careful not to introduce deadlocks - * we don't free the old io scheduler, before we have allocated what we * need for the new one. this way we have a chance of going back to the old |
cb98fc8bb [BLOCK] Reimpleme... |
976 |
* one, if the new one fails init for some reason. |
1da177e4c Linux-2.6.12-rc2 |
977 |
*/ |
165125e1e [BLOCK] Get rid o... |
978 |
static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) |
1da177e4c Linux-2.6.12-rc2 |
979 |
{ |
cb98fc8bb [BLOCK] Reimpleme... |
980 |
elevator_t *old_elevator, *e; |
bc1c11697 [PATCH] elevator ... |
981 |
void *data; |
1da177e4c Linux-2.6.12-rc2 |
982 |
|
cb98fc8bb [BLOCK] Reimpleme... |
983 984 985 |
/* * Allocate new elevator */ |
b5deef901 [PATCH] Make sure... |
986 |
e = elevator_alloc(q, new_e); |
1da177e4c Linux-2.6.12-rc2 |
987 |
if (!e) |
3d1ab40f4 [PATCH] elevator_... |
988 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
989 |
|
bc1c11697 [PATCH] elevator ... |
990 991 992 993 994 |
data = elevator_init_queue(q, e); if (!data) { kobject_put(&e->kobj); return 0; } |
1da177e4c Linux-2.6.12-rc2 |
995 |
/* |
cb98fc8bb [BLOCK] Reimpleme... |
996 |
* Turn on BYPASS and drain all requests w/ elevator private data |
1da177e4c Linux-2.6.12-rc2 |
997 |
*/ |
cb98fc8bb [BLOCK] Reimpleme... |
998 |
spin_lock_irq(q->queue_lock); |
64521d1a3 [BLOCK] elevator ... |
999 |
set_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags); |
cb98fc8bb [BLOCK] Reimpleme... |
1000 |
|
15853af9f [BLOCK] Implement... |
1001 |
elv_drain_elevator(q); |
cb98fc8bb [BLOCK] Reimpleme... |
1002 1003 |
while (q->rq.elvpriv) { |
407df2aa2 [BLOCK] elevator:... |
1004 1005 |
blk_remove_plug(q); q->request_fn(q); |
cb98fc8bb [BLOCK] Reimpleme... |
1006 |
spin_unlock_irq(q->queue_lock); |
64521d1a3 [BLOCK] elevator ... |
1007 |
msleep(10); |
cb98fc8bb [BLOCK] Reimpleme... |
1008 |
spin_lock_irq(q->queue_lock); |
15853af9f [BLOCK] Implement... |
1009 |
elv_drain_elevator(q); |
cb98fc8bb [BLOCK] Reimpleme... |
1010 |
} |
1da177e4c Linux-2.6.12-rc2 |
1011 |
/* |
bc1c11697 [PATCH] elevator ... |
1012 |
* Remember old elevator. |
1da177e4c Linux-2.6.12-rc2 |
1013 |
*/ |
1da177e4c Linux-2.6.12-rc2 |
1014 1015 1016 |
old_elevator = q->elevator; /* |
1da177e4c Linux-2.6.12-rc2 |
1017 1018 |
* attach and start new elevator */ |
bc1c11697 [PATCH] elevator ... |
1019 1020 1021 1022 1023 |
elevator_attach(q, e, data); spin_unlock_irq(q->queue_lock); __elv_unregister_queue(old_elevator); |
1da177e4c Linux-2.6.12-rc2 |
1024 1025 1026 1027 1028 |
if (elv_register_queue(q)) goto fail_register; /* |
cb98fc8bb [BLOCK] Reimpleme... |
1029 |
* finally exit old elevator and turn off BYPASS. |
1da177e4c Linux-2.6.12-rc2 |
1030 1031 |
*/ elevator_exit(old_elevator); |
64521d1a3 [BLOCK] elevator ... |
1032 |
clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags); |
3d1ab40f4 [PATCH] elevator_... |
1033 |
return 1; |
1da177e4c Linux-2.6.12-rc2 |
1034 1035 1036 1037 1038 1039 1040 |
fail_register: /* * switch failed, exit the new io scheduler and reattach the old * one again (along with re-adding the sysfs dir) */ elevator_exit(e); |
1da177e4c Linux-2.6.12-rc2 |
1041 1042 |
q->elevator = old_elevator; elv_register_queue(q); |
64521d1a3 [BLOCK] elevator ... |
1043 |
clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags); |
3d1ab40f4 [PATCH] elevator_... |
1044 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
1045 |
} |
165125e1e [BLOCK] Get rid o... |
1046 1047 |
ssize_t elv_iosched_store(struct request_queue *q, const char *name, size_t count) |
1da177e4c Linux-2.6.12-rc2 |
1048 1049 |
{ char elevator_name[ELV_NAME_MAX]; |
be5612356 [BLOCK] fix strin... |
1050 |
size_t len; |
1da177e4c Linux-2.6.12-rc2 |
1051 |
struct elevator_type *e; |
be5612356 [BLOCK] fix strin... |
1052 1053 1054 |
elevator_name[sizeof(elevator_name) - 1] = '\0'; strncpy(elevator_name, name, sizeof(elevator_name) - 1); len = strlen(elevator_name); |
1da177e4c Linux-2.6.12-rc2 |
1055 |
|
be5612356 [BLOCK] fix strin... |
1056 1057 1058 |
if (len && elevator_name[len - 1] == ' ') elevator_name[len - 1] = '\0'; |
1da177e4c Linux-2.6.12-rc2 |
1059 1060 1061 1062 1063 1064 1065 |
e = elevator_get(elevator_name); if (!e) { printk(KERN_ERR "elevator: type %s not found ", elevator_name); return -EINVAL; } |
2ca7d93bb [PATCH] block cle... |
1066 1067 |
if (!strcmp(elevator_name, q->elevator->elevator_type->elevator_name)) { elevator_put(e); |
1da177e4c Linux-2.6.12-rc2 |
1068 |
return count; |
2ca7d93bb [PATCH] block cle... |
1069 |
} |
1da177e4c Linux-2.6.12-rc2 |
1070 |
|
3d1ab40f4 [PATCH] elevator_... |
1071 |
if (!elevator_switch(q, e)) |
4eb166d98 block: make eleva... |
1072 1073 1074 |
printk(KERN_ERR "elevator: switch to %s failed ", elevator_name); |
1da177e4c Linux-2.6.12-rc2 |
1075 1076 |
return count; } |
165125e1e [BLOCK] Get rid o... |
1077 |
ssize_t elv_iosched_show(struct request_queue *q, char *name) |
1da177e4c Linux-2.6.12-rc2 |
1078 1079 1080 |
{ elevator_t *e = q->elevator; struct elevator_type *elv = e->elevator_type; |
70cee26e0 Use list_for_each... |
1081 |
struct elevator_type *__e; |
1da177e4c Linux-2.6.12-rc2 |
1082 |
int len = 0; |
2a12dcd71 [PATCH] elevator:... |
1083 |
spin_lock(&elv_list_lock); |
70cee26e0 Use list_for_each... |
1084 |
list_for_each_entry(__e, &elv_list, list) { |
1da177e4c Linux-2.6.12-rc2 |
1085 1086 1087 1088 1089 |
if (!strcmp(elv->elevator_name, __e->elevator_name)) len += sprintf(name+len, "[%s] ", elv->elevator_name); else len += sprintf(name+len, "%s ", __e->elevator_name); } |
2a12dcd71 [PATCH] elevator:... |
1090 |
spin_unlock(&elv_list_lock); |
1da177e4c Linux-2.6.12-rc2 |
1091 1092 1093 1094 1095 |
len += sprintf(len+name, " "); return len; } |
165125e1e [BLOCK] Get rid o... |
1096 1097 |
struct request *elv_rb_former_request(struct request_queue *q, struct request *rq) |
2e662b65f [PATCH] elevator:... |
1098 1099 1100 1101 1102 1103 1104 1105 |
{ struct rb_node *rbprev = rb_prev(&rq->rb_node); if (rbprev) return rb_entry_rq(rbprev); return NULL; } |
2e662b65f [PATCH] elevator:... |
1106 |
EXPORT_SYMBOL(elv_rb_former_request); |
165125e1e [BLOCK] Get rid o... |
1107 1108 |
struct request *elv_rb_latter_request(struct request_queue *q, struct request *rq) |
2e662b65f [PATCH] elevator:... |
1109 1110 1111 1112 1113 1114 1115 1116 |
{ struct rb_node *rbnext = rb_next(&rq->rb_node); if (rbnext) return rb_entry_rq(rbnext); return NULL; } |
2e662b65f [PATCH] elevator:... |
1117 |
EXPORT_SYMBOL(elv_rb_latter_request); |