diff options
Diffstat (limited to 'block/deadline-iosched.c')
-rw-r--r-- | block/deadline-iosched.c | 194 |
1 files changed, 52 insertions, 142 deletions
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c index 8300ba1f15a0..3b3b4414170e 100644 --- a/block/deadline-iosched.c +++ b/block/deadline-iosched.c | |||
@@ -37,7 +37,7 @@ struct deadline_data { | |||
37 | /* | 37 | /* |
38 | * next in sort order. read, write or both are NULL | 38 | * next in sort order. read, write or both are NULL |
39 | */ | 39 | */ |
40 | struct deadline_rq *next_drq[2]; | 40 | struct request *next_rq[2]; |
41 | unsigned int batching; /* number of sequential requests made */ | 41 | unsigned int batching; /* number of sequential requests made */ |
42 | sector_t last_sector; /* head position */ | 42 | sector_t last_sector; /* head position */ |
43 | unsigned int starved; /* times reads have starved writes */ | 43 | unsigned int starved; /* times reads have starved writes */ |
@@ -49,34 +49,14 @@ struct deadline_data { | |||
49 | int fifo_batch; | 49 | int fifo_batch; |
50 | int writes_starved; | 50 | int writes_starved; |
51 | int front_merges; | 51 | int front_merges; |
52 | |||
53 | mempool_t *drq_pool; | ||
54 | }; | 52 | }; |
55 | 53 | ||
56 | /* | 54 | static void deadline_move_request(struct deadline_data *, struct request *); |
57 | * pre-request data. | ||
58 | */ | ||
59 | struct deadline_rq { | ||
60 | struct request *request; | ||
61 | |||
62 | /* | ||
63 | * expire fifo | ||
64 | */ | ||
65 | struct list_head fifo; | ||
66 | unsigned long expires; | ||
67 | }; | ||
68 | |||
69 | static void deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq); | ||
70 | |||
71 | static kmem_cache_t *drq_pool; | ||
72 | |||
73 | #define RQ_DATA(rq) ((struct deadline_rq *) (rq)->elevator_private) | ||
74 | 55 | ||
75 | #define RQ_RB_ROOT(dd, rq) (&(dd)->sort_list[rq_data_dir((rq))]) | 56 | #define RQ_RB_ROOT(dd, rq) (&(dd)->sort_list[rq_data_dir((rq))]) |
76 | #define DRQ_RB_ROOT(dd, drq) RQ_RB_ROOT((drq)->request) | ||
77 | 57 | ||
78 | static void | 58 | static void |
79 | deadline_add_drq_rb(struct deadline_data *dd, struct request *rq) | 59 | deadline_add_rq_rb(struct deadline_data *dd, struct request *rq) |
80 | { | 60 | { |
81 | struct rb_root *root = RQ_RB_ROOT(dd, rq); | 61 | struct rb_root *root = RQ_RB_ROOT(dd, rq); |
82 | struct request *__alias; | 62 | struct request *__alias; |
@@ -84,45 +64,43 @@ deadline_add_drq_rb(struct deadline_data *dd, struct request *rq) | |||
84 | retry: | 64 | retry: |
85 | __alias = elv_rb_add(root, rq); | 65 | __alias = elv_rb_add(root, rq); |
86 | if (unlikely(__alias)) { | 66 | if (unlikely(__alias)) { |
87 | deadline_move_request(dd, RQ_DATA(__alias)); | 67 | deadline_move_request(dd, __alias); |
88 | goto retry; | 68 | goto retry; |
89 | } | 69 | } |
90 | } | 70 | } |
91 | 71 | ||
92 | static inline void | 72 | static inline void |
93 | deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq) | 73 | deadline_del_rq_rb(struct deadline_data *dd, struct request *rq) |
94 | { | 74 | { |
95 | struct request *rq = drq->request; | ||
96 | const int data_dir = rq_data_dir(rq); | 75 | const int data_dir = rq_data_dir(rq); |
97 | 76 | ||
98 | if (dd->next_drq[data_dir] == drq) { | 77 | if (dd->next_rq[data_dir] == rq) { |
99 | struct rb_node *rbnext = rb_next(&rq->rb_node); | 78 | struct rb_node *rbnext = rb_next(&rq->rb_node); |
100 | 79 | ||
101 | dd->next_drq[data_dir] = NULL; | 80 | dd->next_rq[data_dir] = NULL; |
102 | if (rbnext) | 81 | if (rbnext) |
103 | dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext)); | 82 | dd->next_rq[data_dir] = rb_entry_rq(rbnext); |
104 | } | 83 | } |
105 | 84 | ||
106 | elv_rb_del(RQ_RB_ROOT(dd, rq), rq); | 85 | elv_rb_del(RQ_RB_ROOT(dd, rq), rq); |
107 | } | 86 | } |
108 | 87 | ||
109 | /* | 88 | /* |
110 | * add drq to rbtree and fifo | 89 | * add rq to rbtree and fifo |
111 | */ | 90 | */ |
112 | static void | 91 | static void |
113 | deadline_add_request(struct request_queue *q, struct request *rq) | 92 | deadline_add_request(struct request_queue *q, struct request *rq) |
114 | { | 93 | { |
115 | struct deadline_data *dd = q->elevator->elevator_data; | 94 | struct deadline_data *dd = q->elevator->elevator_data; |
116 | struct deadline_rq *drq = RQ_DATA(rq); | 95 | const int data_dir = rq_data_dir(rq); |
117 | const int data_dir = rq_data_dir(drq->request); | ||
118 | 96 | ||
119 | deadline_add_drq_rb(dd, rq); | 97 | deadline_add_rq_rb(dd, rq); |
120 | 98 | ||
121 | /* | 99 | /* |
122 | * set expire time (only used for reads) and add to fifo list | 100 | * set expire time (only used for reads) and add to fifo list |
123 | */ | 101 | */ |
124 | drq->expires = jiffies + dd->fifo_expire[data_dir]; | 102 | rq_set_fifo_time(rq, jiffies + dd->fifo_expire[data_dir]); |
125 | list_add_tail(&drq->fifo, &dd->fifo_list[data_dir]); | 103 | list_add_tail(&rq->queuelist, &dd->fifo_list[data_dir]); |
126 | } | 104 | } |
127 | 105 | ||
128 | /* | 106 | /* |
@@ -130,11 +108,10 @@ deadline_add_request(struct request_queue *q, struct request *rq) | |||
130 | */ | 108 | */ |
131 | static void deadline_remove_request(request_queue_t *q, struct request *rq) | 109 | static void deadline_remove_request(request_queue_t *q, struct request *rq) |
132 | { | 110 | { |
133 | struct deadline_rq *drq = RQ_DATA(rq); | ||
134 | struct deadline_data *dd = q->elevator->elevator_data; | 111 | struct deadline_data *dd = q->elevator->elevator_data; |
135 | 112 | ||
136 | list_del_init(&drq->fifo); | 113 | rq_fifo_clear(rq); |
137 | deadline_del_drq_rb(dd, drq); | 114 | deadline_del_rq_rb(dd, rq); |
138 | } | 115 | } |
139 | 116 | ||
140 | static int | 117 | static int |
@@ -177,7 +154,7 @@ static void deadline_merged_request(request_queue_t *q, struct request *req, | |||
177 | */ | 154 | */ |
178 | if (type == ELEVATOR_FRONT_MERGE) { | 155 | if (type == ELEVATOR_FRONT_MERGE) { |
179 | elv_rb_del(RQ_RB_ROOT(dd, req), req); | 156 | elv_rb_del(RQ_RB_ROOT(dd, req), req); |
180 | deadline_add_drq_rb(dd, req); | 157 | deadline_add_rq_rb(dd, req); |
181 | } | 158 | } |
182 | } | 159 | } |
183 | 160 | ||
@@ -185,20 +162,14 @@ static void | |||
185 | deadline_merged_requests(request_queue_t *q, struct request *req, | 162 | deadline_merged_requests(request_queue_t *q, struct request *req, |
186 | struct request *next) | 163 | struct request *next) |
187 | { | 164 | { |
188 | struct deadline_rq *drq = RQ_DATA(req); | ||
189 | struct deadline_rq *dnext = RQ_DATA(next); | ||
190 | |||
191 | BUG_ON(!drq); | ||
192 | BUG_ON(!dnext); | ||
193 | |||
194 | /* | 165 | /* |
195 | * if dnext expires before drq, assign its expire time to drq | 166 | * if next expires before rq, assign its expire time to rq |
196 | * and move into dnext position (dnext will be deleted) in fifo | 167 | * and move into next position (next will be deleted) in fifo |
197 | */ | 168 | */ |
198 | if (!list_empty(&drq->fifo) && !list_empty(&dnext->fifo)) { | 169 | if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) { |
199 | if (time_before(dnext->expires, drq->expires)) { | 170 | if (time_before(rq_fifo_time(next), rq_fifo_time(req))) { |
200 | list_move(&drq->fifo, &dnext->fifo); | 171 | list_move(&req->queuelist, &next->queuelist); |
201 | drq->expires = dnext->expires; | 172 | rq_set_fifo_time(req, rq_fifo_time(next)); |
202 | } | 173 | } |
203 | } | 174 | } |
204 | 175 | ||
@@ -212,53 +183,50 @@ deadline_merged_requests(request_queue_t *q, struct request *req, | |||
212 | * move request from sort list to dispatch queue. | 183 | * move request from sort list to dispatch queue. |
213 | */ | 184 | */ |
214 | static inline void | 185 | static inline void |
215 | deadline_move_to_dispatch(struct deadline_data *dd, struct deadline_rq *drq) | 186 | deadline_move_to_dispatch(struct deadline_data *dd, struct request *rq) |
216 | { | 187 | { |
217 | request_queue_t *q = drq->request->q; | 188 | request_queue_t *q = rq->q; |
218 | 189 | ||
219 | deadline_remove_request(q, drq->request); | 190 | deadline_remove_request(q, rq); |
220 | elv_dispatch_add_tail(q, drq->request); | 191 | elv_dispatch_add_tail(q, rq); |
221 | } | 192 | } |
222 | 193 | ||
223 | /* | 194 | /* |
224 | * move an entry to dispatch queue | 195 | * move an entry to dispatch queue |
225 | */ | 196 | */ |
226 | static void | 197 | static void |
227 | deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq) | 198 | deadline_move_request(struct deadline_data *dd, struct request *rq) |
228 | { | 199 | { |
229 | struct request *rq = drq->request; | ||
230 | const int data_dir = rq_data_dir(rq); | 200 | const int data_dir = rq_data_dir(rq); |
231 | struct rb_node *rbnext = rb_next(&rq->rb_node); | 201 | struct rb_node *rbnext = rb_next(&rq->rb_node); |
232 | 202 | ||
233 | dd->next_drq[READ] = NULL; | 203 | dd->next_rq[READ] = NULL; |
234 | dd->next_drq[WRITE] = NULL; | 204 | dd->next_rq[WRITE] = NULL; |
235 | 205 | ||
236 | if (rbnext) | 206 | if (rbnext) |
237 | dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext)); | 207 | dd->next_rq[data_dir] = rb_entry_rq(rbnext); |
238 | 208 | ||
239 | dd->last_sector = drq->request->sector + drq->request->nr_sectors; | 209 | dd->last_sector = rq->sector + rq->nr_sectors; |
240 | 210 | ||
241 | /* | 211 | /* |
242 | * take it off the sort and fifo list, move | 212 | * take it off the sort and fifo list, move |
243 | * to dispatch queue | 213 | * to dispatch queue |
244 | */ | 214 | */ |
245 | deadline_move_to_dispatch(dd, drq); | 215 | deadline_move_to_dispatch(dd, rq); |
246 | } | 216 | } |
247 | 217 | ||
248 | #define list_entry_fifo(ptr) list_entry((ptr), struct deadline_rq, fifo) | ||
249 | |||
250 | /* | 218 | /* |
251 | * deadline_check_fifo returns 0 if there are no expired reads on the fifo, | 219 | * deadline_check_fifo returns 0 if there are no expired reads on the fifo, |
252 | * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir]) | 220 | * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir]) |
253 | */ | 221 | */ |
254 | static inline int deadline_check_fifo(struct deadline_data *dd, int ddir) | 222 | static inline int deadline_check_fifo(struct deadline_data *dd, int ddir) |
255 | { | 223 | { |
256 | struct deadline_rq *drq = list_entry_fifo(dd->fifo_list[ddir].next); | 224 | struct request *rq = rq_entry_fifo(dd->fifo_list[ddir].next); |
257 | 225 | ||
258 | /* | 226 | /* |
259 | * drq is expired! | 227 | * rq is expired! |
260 | */ | 228 | */ |
261 | if (time_after(jiffies, drq->expires)) | 229 | if (time_after(jiffies, rq_fifo_time(rq))) |
262 | return 1; | 230 | return 1; |
263 | 231 | ||
264 | return 0; | 232 | return 0; |
@@ -273,21 +241,21 @@ static int deadline_dispatch_requests(request_queue_t *q, int force) | |||
273 | struct deadline_data *dd = q->elevator->elevator_data; | 241 | struct deadline_data *dd = q->elevator->elevator_data; |
274 | const int reads = !list_empty(&dd->fifo_list[READ]); | 242 | const int reads = !list_empty(&dd->fifo_list[READ]); |
275 | const int writes = !list_empty(&dd->fifo_list[WRITE]); | 243 | const int writes = !list_empty(&dd->fifo_list[WRITE]); |
276 | struct deadline_rq *drq; | 244 | struct request *rq; |
277 | int data_dir; | 245 | int data_dir; |
278 | 246 | ||
279 | /* | 247 | /* |
280 | * batches are currently reads XOR writes | 248 | * batches are currently reads XOR writes |
281 | */ | 249 | */ |
282 | if (dd->next_drq[WRITE]) | 250 | if (dd->next_rq[WRITE]) |
283 | drq = dd->next_drq[WRITE]; | 251 | rq = dd->next_rq[WRITE]; |
284 | else | 252 | else |
285 | drq = dd->next_drq[READ]; | 253 | rq = dd->next_rq[READ]; |
286 | 254 | ||
287 | if (drq) { | 255 | if (rq) { |
288 | /* we have a "next request" */ | 256 | /* we have a "next request" */ |
289 | 257 | ||
290 | if (dd->last_sector != drq->request->sector) | 258 | if (dd->last_sector != rq->sector) |
291 | /* end the batch on a non sequential request */ | 259 | /* end the batch on a non sequential request */ |
292 | dd->batching += dd->fifo_batch; | 260 | dd->batching += dd->fifo_batch; |
293 | 261 | ||
@@ -336,34 +304,33 @@ dispatch_find_request: | |||
336 | if (deadline_check_fifo(dd, data_dir)) { | 304 | if (deadline_check_fifo(dd, data_dir)) { |
337 | /* An expired request exists - satisfy it */ | 305 | /* An expired request exists - satisfy it */ |
338 | dd->batching = 0; | 306 | dd->batching = 0; |
339 | drq = list_entry_fifo(dd->fifo_list[data_dir].next); | 307 | rq = rq_entry_fifo(dd->fifo_list[data_dir].next); |
340 | 308 | ||
341 | } else if (dd->next_drq[data_dir]) { | 309 | } else if (dd->next_rq[data_dir]) { |
342 | /* | 310 | /* |
343 | * The last req was the same dir and we have a next request in | 311 | * The last req was the same dir and we have a next request in |
344 | * sort order. No expired requests so continue on from here. | 312 | * sort order. No expired requests so continue on from here. |
345 | */ | 313 | */ |
346 | drq = dd->next_drq[data_dir]; | 314 | rq = dd->next_rq[data_dir]; |
347 | } else { | 315 | } else { |
348 | struct rb_node *n; | 316 | struct rb_node *node; |
349 | |||
350 | /* | 317 | /* |
351 | * The last req was the other direction or we have run out of | 318 | * The last req was the other direction or we have run out of |
352 | * higher-sectored requests. Go back to the lowest sectored | 319 | * higher-sectored requests. Go back to the lowest sectored |
353 | * request (1 way elevator) and start a new batch. | 320 | * request (1 way elevator) and start a new batch. |
354 | */ | 321 | */ |
355 | dd->batching = 0; | 322 | dd->batching = 0; |
356 | n = rb_first(&dd->sort_list[data_dir]); | 323 | node = rb_first(&dd->sort_list[data_dir]); |
357 | if (n) | 324 | if (node) |
358 | drq = RQ_DATA(rb_entry_rq(n)); | 325 | rq = rb_entry_rq(node); |
359 | } | 326 | } |
360 | 327 | ||
361 | dispatch_request: | 328 | dispatch_request: |
362 | /* | 329 | /* |
363 | * drq is the selected appropriate request. | 330 | * rq is the selected appropriate request. |
364 | */ | 331 | */ |
365 | dd->batching++; | 332 | dd->batching++; |
366 | deadline_move_request(dd, drq); | 333 | deadline_move_request(dd, rq); |
367 | 334 | ||
368 | return 1; | 335 | return 1; |
369 | } | 336 | } |
@@ -383,33 +350,21 @@ static void deadline_exit_queue(elevator_t *e) | |||
383 | BUG_ON(!list_empty(&dd->fifo_list[READ])); | 350 | BUG_ON(!list_empty(&dd->fifo_list[READ])); |
384 | BUG_ON(!list_empty(&dd->fifo_list[WRITE])); | 351 | BUG_ON(!list_empty(&dd->fifo_list[WRITE])); |
385 | 352 | ||
386 | mempool_destroy(dd->drq_pool); | ||
387 | kfree(dd); | 353 | kfree(dd); |
388 | } | 354 | } |
389 | 355 | ||
390 | /* | 356 | /* |
391 | * initialize elevator private data (deadline_data), and alloc a drq for | 357 | * initialize elevator private data (deadline_data). |
392 | * each request on the free lists | ||
393 | */ | 358 | */ |
394 | static void *deadline_init_queue(request_queue_t *q, elevator_t *e) | 359 | static void *deadline_init_queue(request_queue_t *q, elevator_t *e) |
395 | { | 360 | { |
396 | struct deadline_data *dd; | 361 | struct deadline_data *dd; |
397 | 362 | ||
398 | if (!drq_pool) | ||
399 | return NULL; | ||
400 | |||
401 | dd = kmalloc_node(sizeof(*dd), GFP_KERNEL, q->node); | 363 | dd = kmalloc_node(sizeof(*dd), GFP_KERNEL, q->node); |
402 | if (!dd) | 364 | if (!dd) |
403 | return NULL; | 365 | return NULL; |
404 | memset(dd, 0, sizeof(*dd)); | 366 | memset(dd, 0, sizeof(*dd)); |
405 | 367 | ||
406 | dd->drq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab, | ||
407 | mempool_free_slab, drq_pool, q->node); | ||
408 | if (!dd->drq_pool) { | ||
409 | kfree(dd); | ||
410 | return NULL; | ||
411 | } | ||
412 | |||
413 | INIT_LIST_HEAD(&dd->fifo_list[READ]); | 368 | INIT_LIST_HEAD(&dd->fifo_list[READ]); |
414 | INIT_LIST_HEAD(&dd->fifo_list[WRITE]); | 369 | INIT_LIST_HEAD(&dd->fifo_list[WRITE]); |
415 | dd->sort_list[READ] = RB_ROOT; | 370 | dd->sort_list[READ] = RB_ROOT; |
@@ -422,36 +377,6 @@ static void *deadline_init_queue(request_queue_t *q, elevator_t *e) | |||
422 | return dd; | 377 | return dd; |
423 | } | 378 | } |
424 | 379 | ||
425 | static void deadline_put_request(request_queue_t *q, struct request *rq) | ||
426 | { | ||
427 | struct deadline_data *dd = q->elevator->elevator_data; | ||
428 | struct deadline_rq *drq = RQ_DATA(rq); | ||
429 | |||
430 | mempool_free(drq, dd->drq_pool); | ||
431 | rq->elevator_private = NULL; | ||
432 | } | ||
433 | |||
434 | static int | ||
435 | deadline_set_request(request_queue_t *q, struct request *rq, struct bio *bio, | ||
436 | gfp_t gfp_mask) | ||
437 | { | ||
438 | struct deadline_data *dd = q->elevator->elevator_data; | ||
439 | struct deadline_rq *drq; | ||
440 | |||
441 | drq = mempool_alloc(dd->drq_pool, gfp_mask); | ||
442 | if (drq) { | ||
443 | memset(drq, 0, sizeof(*drq)); | ||
444 | drq->request = rq; | ||
445 | |||
446 | INIT_LIST_HEAD(&drq->fifo); | ||
447 | |||
448 | rq->elevator_private = drq; | ||
449 | return 0; | ||
450 | } | ||
451 | |||
452 | return 1; | ||
453 | } | ||
454 | |||
455 | /* | 380 | /* |
456 | * sysfs parts below | 381 | * sysfs parts below |
457 | */ | 382 | */ |
@@ -533,8 +458,6 @@ static struct elevator_type iosched_deadline = { | |||
533 | .elevator_queue_empty_fn = deadline_queue_empty, | 458 | .elevator_queue_empty_fn = deadline_queue_empty, |
534 | .elevator_former_req_fn = elv_rb_former_request, | 459 | .elevator_former_req_fn = elv_rb_former_request, |
535 | .elevator_latter_req_fn = elv_rb_latter_request, | 460 | .elevator_latter_req_fn = elv_rb_latter_request, |
536 | .elevator_set_req_fn = deadline_set_request, | ||
537 | .elevator_put_req_fn = deadline_put_request, | ||
538 | .elevator_init_fn = deadline_init_queue, | 461 | .elevator_init_fn = deadline_init_queue, |
539 | .elevator_exit_fn = deadline_exit_queue, | 462 | .elevator_exit_fn = deadline_exit_queue, |
540 | }, | 463 | }, |
@@ -546,24 +469,11 @@ static struct elevator_type iosched_deadline = { | |||
546 | 469 | ||
547 | static int __init deadline_init(void) | 470 | static int __init deadline_init(void) |
548 | { | 471 | { |
549 | int ret; | 472 | return elv_register(&iosched_deadline); |
550 | |||
551 | drq_pool = kmem_cache_create("deadline_drq", sizeof(struct deadline_rq), | ||
552 | 0, 0, NULL, NULL); | ||
553 | |||
554 | if (!drq_pool) | ||
555 | return -ENOMEM; | ||
556 | |||
557 | ret = elv_register(&iosched_deadline); | ||
558 | if (ret) | ||
559 | kmem_cache_destroy(drq_pool); | ||
560 | |||
561 | return ret; | ||
562 | } | 473 | } |
563 | 474 | ||
564 | static void __exit deadline_exit(void) | 475 | static void __exit deadline_exit(void) |
565 | { | 476 | { |
566 | kmem_cache_destroy(drq_pool); | ||
567 | elv_unregister(&iosched_deadline); | 477 | elv_unregister(&iosched_deadline); |
568 | } | 478 | } |
569 | 479 | ||