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bd166ef1 JA |
1 | /* |
2 | * blk-mq scheduling framework | |
3 | * | |
4 | * Copyright (C) 2016 Jens Axboe | |
5 | */ | |
6 | #include <linux/kernel.h> | |
7 | #include <linux/module.h> | |
8 | #include <linux/blk-mq.h> | |
9 | ||
10 | #include <trace/events/block.h> | |
11 | ||
12 | #include "blk.h" | |
13 | #include "blk-mq.h" | |
d332ce09 | 14 | #include "blk-mq-debugfs.h" |
bd166ef1 JA |
15 | #include "blk-mq-sched.h" |
16 | #include "blk-mq-tag.h" | |
17 | #include "blk-wbt.h" | |
18 | ||
19 | void blk_mq_sched_free_hctx_data(struct request_queue *q, | |
20 | void (*exit)(struct blk_mq_hw_ctx *)) | |
21 | { | |
22 | struct blk_mq_hw_ctx *hctx; | |
23 | int i; | |
24 | ||
25 | queue_for_each_hw_ctx(q, hctx, i) { | |
26 | if (exit && hctx->sched_data) | |
27 | exit(hctx); | |
28 | kfree(hctx->sched_data); | |
29 | hctx->sched_data = NULL; | |
30 | } | |
31 | } | |
32 | EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data); | |
33 | ||
bd166ef1 | 34 | static void __blk_mq_sched_assign_ioc(struct request_queue *q, |
f1ba8261 PV |
35 | struct request *rq, |
36 | struct bio *bio, | |
37 | struct io_context *ioc) | |
bd166ef1 JA |
38 | { |
39 | struct io_cq *icq; | |
40 | ||
41 | spin_lock_irq(q->queue_lock); | |
42 | icq = ioc_lookup_icq(ioc, q); | |
43 | spin_unlock_irq(q->queue_lock); | |
44 | ||
45 | if (!icq) { | |
46 | icq = ioc_create_icq(ioc, q, GFP_ATOMIC); | |
47 | if (!icq) | |
48 | return; | |
49 | } | |
50 | ||
51 | rq->elv.icq = icq; | |
f1ba8261 | 52 | if (!blk_mq_sched_get_rq_priv(q, rq, bio)) { |
bd166ef1 JA |
53 | rq->rq_flags |= RQF_ELVPRIV; |
54 | get_io_context(icq->ioc); | |
55 | return; | |
56 | } | |
57 | ||
58 | rq->elv.icq = NULL; | |
59 | } | |
60 | ||
61 | static void blk_mq_sched_assign_ioc(struct request_queue *q, | |
62 | struct request *rq, struct bio *bio) | |
63 | { | |
64 | struct io_context *ioc; | |
65 | ||
66 | ioc = rq_ioc(bio); | |
67 | if (ioc) | |
f1ba8261 | 68 | __blk_mq_sched_assign_ioc(q, rq, bio, ioc); |
bd166ef1 JA |
69 | } |
70 | ||
8e8320c9 JA |
71 | /* |
72 | * Mark a hardware queue as needing a restart. For shared queues, maintain | |
73 | * a count of how many hardware queues are marked for restart. | |
74 | */ | |
75 | static void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx) | |
76 | { | |
77 | if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) | |
78 | return; | |
79 | ||
80 | if (hctx->flags & BLK_MQ_F_TAG_SHARED) { | |
81 | struct request_queue *q = hctx->queue; | |
82 | ||
83 | if (!test_and_set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) | |
84 | atomic_inc(&q->shared_hctx_restart); | |
85 | } else | |
86 | set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); | |
87 | } | |
88 | ||
89 | static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx) | |
90 | { | |
91 | if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) | |
92 | return false; | |
93 | ||
94 | if (hctx->flags & BLK_MQ_F_TAG_SHARED) { | |
95 | struct request_queue *q = hctx->queue; | |
96 | ||
97 | if (test_and_clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) | |
98 | atomic_dec(&q->shared_hctx_restart); | |
99 | } else | |
100 | clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); | |
101 | ||
102 | if (blk_mq_hctx_has_pending(hctx)) { | |
103 | blk_mq_run_hw_queue(hctx, true); | |
104 | return true; | |
105 | } | |
106 | ||
107 | return false; | |
108 | } | |
109 | ||
bd166ef1 JA |
110 | struct request *blk_mq_sched_get_request(struct request_queue *q, |
111 | struct bio *bio, | |
112 | unsigned int op, | |
113 | struct blk_mq_alloc_data *data) | |
114 | { | |
115 | struct elevator_queue *e = q->elevator; | |
bd166ef1 | 116 | struct request *rq; |
bd166ef1 JA |
117 | |
118 | blk_queue_enter_live(q); | |
6d2809d5 OS |
119 | data->q = q; |
120 | if (likely(!data->ctx)) | |
121 | data->ctx = blk_mq_get_ctx(q); | |
122 | if (likely(!data->hctx)) | |
123 | data->hctx = blk_mq_map_queue(q, data->ctx->cpu); | |
bd166ef1 | 124 | |
9f2779bf | 125 | if (e) { |
bd166ef1 JA |
126 | data->flags |= BLK_MQ_REQ_INTERNAL; |
127 | ||
128 | /* | |
129 | * Flush requests are special and go directly to the | |
130 | * dispatch list. | |
131 | */ | |
f73f44eb | 132 | if (!op_is_flush(op) && e->type->ops.mq.get_request) { |
bd166ef1 JA |
133 | rq = e->type->ops.mq.get_request(q, op, data); |
134 | if (rq) | |
135 | rq->rq_flags |= RQF_QUEUED; | |
136 | } else | |
137 | rq = __blk_mq_alloc_request(data, op); | |
138 | } else { | |
139 | rq = __blk_mq_alloc_request(data, op); | |
bd166ef1 JA |
140 | } |
141 | ||
142 | if (rq) { | |
f73f44eb | 143 | if (!op_is_flush(op)) { |
bd166ef1 JA |
144 | rq->elv.icq = NULL; |
145 | if (e && e->type->icq_cache) | |
146 | blk_mq_sched_assign_ioc(q, rq, bio); | |
147 | } | |
148 | data->hctx->queued++; | |
149 | return rq; | |
150 | } | |
151 | ||
152 | blk_queue_exit(q); | |
153 | return NULL; | |
154 | } | |
155 | ||
156 | void blk_mq_sched_put_request(struct request *rq) | |
157 | { | |
158 | struct request_queue *q = rq->q; | |
159 | struct elevator_queue *e = q->elevator; | |
160 | ||
161 | if (rq->rq_flags & RQF_ELVPRIV) { | |
162 | blk_mq_sched_put_rq_priv(rq->q, rq); | |
163 | if (rq->elv.icq) { | |
164 | put_io_context(rq->elv.icq->ioc); | |
165 | rq->elv.icq = NULL; | |
166 | } | |
167 | } | |
168 | ||
169 | if ((rq->rq_flags & RQF_QUEUED) && e && e->type->ops.mq.put_request) | |
170 | e->type->ops.mq.put_request(rq); | |
171 | else | |
172 | blk_mq_finish_request(rq); | |
173 | } | |
174 | ||
175 | void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) | |
176 | { | |
81380ca1 OS |
177 | struct request_queue *q = hctx->queue; |
178 | struct elevator_queue *e = q->elevator; | |
64765a75 JA |
179 | const bool has_sched_dispatch = e && e->type->ops.mq.dispatch_request; |
180 | bool did_work = false; | |
bd166ef1 JA |
181 | LIST_HEAD(rq_list); |
182 | ||
183 | if (unlikely(blk_mq_hctx_stopped(hctx))) | |
184 | return; | |
185 | ||
186 | hctx->run++; | |
187 | ||
188 | /* | |
189 | * If we have previous entries on our dispatch list, grab them first for | |
190 | * more fair dispatch. | |
191 | */ | |
192 | if (!list_empty_careful(&hctx->dispatch)) { | |
193 | spin_lock(&hctx->lock); | |
194 | if (!list_empty(&hctx->dispatch)) | |
195 | list_splice_init(&hctx->dispatch, &rq_list); | |
196 | spin_unlock(&hctx->lock); | |
197 | } | |
198 | ||
199 | /* | |
200 | * Only ask the scheduler for requests, if we didn't have residual | |
201 | * requests from the dispatch list. This is to avoid the case where | |
202 | * we only ever dispatch a fraction of the requests available because | |
203 | * of low device queue depth. Once we pull requests out of the IO | |
204 | * scheduler, we can no longer merge or sort them. So it's best to | |
205 | * leave them there for as long as we can. Mark the hw queue as | |
206 | * needing a restart in that case. | |
207 | */ | |
c13660a0 | 208 | if (!list_empty(&rq_list)) { |
d38d3515 | 209 | blk_mq_sched_mark_restart_hctx(hctx); |
81380ca1 | 210 | did_work = blk_mq_dispatch_rq_list(q, &rq_list); |
64765a75 | 211 | } else if (!has_sched_dispatch) { |
c13660a0 | 212 | blk_mq_flush_busy_ctxs(hctx, &rq_list); |
81380ca1 | 213 | blk_mq_dispatch_rq_list(q, &rq_list); |
64765a75 JA |
214 | } |
215 | ||
216 | /* | |
217 | * We want to dispatch from the scheduler if we had no work left | |
218 | * on the dispatch list, OR if we did have work but weren't able | |
219 | * to make progress. | |
220 | */ | |
221 | if (!did_work && has_sched_dispatch) { | |
c13660a0 JA |
222 | do { |
223 | struct request *rq; | |
224 | ||
225 | rq = e->type->ops.mq.dispatch_request(hctx); | |
226 | if (!rq) | |
227 | break; | |
228 | list_add(&rq->queuelist, &rq_list); | |
81380ca1 | 229 | } while (blk_mq_dispatch_rq_list(q, &rq_list)); |
c13660a0 | 230 | } |
bd166ef1 JA |
231 | } |
232 | ||
e4d750c9 JA |
233 | bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, |
234 | struct request **merged_request) | |
bd166ef1 JA |
235 | { |
236 | struct request *rq; | |
bd166ef1 | 237 | |
34fe7c05 CH |
238 | switch (elv_merge(q, &rq, bio)) { |
239 | case ELEVATOR_BACK_MERGE: | |
bd166ef1 JA |
240 | if (!blk_mq_sched_allow_merge(q, rq, bio)) |
241 | return false; | |
34fe7c05 CH |
242 | if (!bio_attempt_back_merge(q, rq, bio)) |
243 | return false; | |
244 | *merged_request = attempt_back_merge(q, rq); | |
245 | if (!*merged_request) | |
246 | elv_merged_request(q, rq, ELEVATOR_BACK_MERGE); | |
247 | return true; | |
248 | case ELEVATOR_FRONT_MERGE: | |
bd166ef1 JA |
249 | if (!blk_mq_sched_allow_merge(q, rq, bio)) |
250 | return false; | |
34fe7c05 CH |
251 | if (!bio_attempt_front_merge(q, rq, bio)) |
252 | return false; | |
253 | *merged_request = attempt_front_merge(q, rq); | |
254 | if (!*merged_request) | |
255 | elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE); | |
256 | return true; | |
257 | default: | |
258 | return false; | |
bd166ef1 | 259 | } |
bd166ef1 JA |
260 | } |
261 | EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); | |
262 | ||
263 | bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) | |
264 | { | |
265 | struct elevator_queue *e = q->elevator; | |
266 | ||
267 | if (e->type->ops.mq.bio_merge) { | |
268 | struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); | |
269 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); | |
270 | ||
271 | blk_mq_put_ctx(ctx); | |
272 | return e->type->ops.mq.bio_merge(hctx, bio); | |
273 | } | |
274 | ||
275 | return false; | |
276 | } | |
277 | ||
278 | bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq) | |
279 | { | |
280 | return rq_mergeable(rq) && elv_attempt_insert_merge(q, rq); | |
281 | } | |
282 | EXPORT_SYMBOL_GPL(blk_mq_sched_try_insert_merge); | |
283 | ||
284 | void blk_mq_sched_request_inserted(struct request *rq) | |
285 | { | |
286 | trace_block_rq_insert(rq->q, rq); | |
287 | } | |
288 | EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted); | |
289 | ||
0cacba6c OS |
290 | static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, |
291 | struct request *rq) | |
bd166ef1 JA |
292 | { |
293 | if (rq->tag == -1) { | |
294 | rq->rq_flags |= RQF_SORTED; | |
295 | return false; | |
296 | } | |
297 | ||
298 | /* | |
299 | * If we already have a real request tag, send directly to | |
300 | * the dispatch list. | |
301 | */ | |
302 | spin_lock(&hctx->lock); | |
303 | list_add(&rq->queuelist, &hctx->dispatch); | |
304 | spin_unlock(&hctx->lock); | |
305 | return true; | |
306 | } | |
bd166ef1 | 307 | |
6d8c6c0f BVA |
308 | /** |
309 | * list_for_each_entry_rcu_rr - iterate in a round-robin fashion over rcu list | |
310 | * @pos: loop cursor. | |
311 | * @skip: the list element that will not be examined. Iteration starts at | |
312 | * @skip->next. | |
313 | * @head: head of the list to examine. This list must have at least one | |
314 | * element, namely @skip. | |
315 | * @member: name of the list_head structure within typeof(*pos). | |
316 | */ | |
317 | #define list_for_each_entry_rcu_rr(pos, skip, head, member) \ | |
318 | for ((pos) = (skip); \ | |
319 | (pos = (pos)->member.next != (head) ? list_entry_rcu( \ | |
320 | (pos)->member.next, typeof(*pos), member) : \ | |
321 | list_entry_rcu((pos)->member.next->next, typeof(*pos), member)), \ | |
322 | (pos) != (skip); ) | |
50e1dab8 | 323 | |
6d8c6c0f BVA |
324 | /* |
325 | * Called after a driver tag has been freed to check whether a hctx needs to | |
326 | * be restarted. Restarts @hctx if its tag set is not shared. Restarts hardware | |
327 | * queues in a round-robin fashion if the tag set of @hctx is shared with other | |
328 | * hardware queues. | |
329 | */ | |
330 | void blk_mq_sched_restart(struct blk_mq_hw_ctx *const hctx) | |
331 | { | |
332 | struct blk_mq_tags *const tags = hctx->tags; | |
333 | struct blk_mq_tag_set *const set = hctx->queue->tag_set; | |
334 | struct request_queue *const queue = hctx->queue, *q; | |
335 | struct blk_mq_hw_ctx *hctx2; | |
336 | unsigned int i, j; | |
337 | ||
338 | if (set->flags & BLK_MQ_F_TAG_SHARED) { | |
8e8320c9 JA |
339 | /* |
340 | * If this is 0, then we know that no hardware queues | |
341 | * have RESTART marked. We're done. | |
342 | */ | |
343 | if (!atomic_read(&queue->shared_hctx_restart)) | |
344 | return; | |
345 | ||
6d8c6c0f BVA |
346 | rcu_read_lock(); |
347 | list_for_each_entry_rcu_rr(q, queue, &set->tag_list, | |
348 | tag_set_list) { | |
349 | queue_for_each_hw_ctx(q, hctx2, i) | |
350 | if (hctx2->tags == tags && | |
351 | blk_mq_sched_restart_hctx(hctx2)) | |
352 | goto done; | |
353 | } | |
354 | j = hctx->queue_num + 1; | |
355 | for (i = 0; i < queue->nr_hw_queues; i++, j++) { | |
356 | if (j == queue->nr_hw_queues) | |
357 | j = 0; | |
358 | hctx2 = queue->queue_hw_ctx[j]; | |
359 | if (hctx2->tags == tags && | |
360 | blk_mq_sched_restart_hctx(hctx2)) | |
361 | break; | |
d38d3515 | 362 | } |
6d8c6c0f BVA |
363 | done: |
364 | rcu_read_unlock(); | |
d38d3515 | 365 | } else { |
50e1dab8 | 366 | blk_mq_sched_restart_hctx(hctx); |
50e1dab8 JA |
367 | } |
368 | } | |
369 | ||
bd6737f1 JA |
370 | /* |
371 | * Add flush/fua to the queue. If we fail getting a driver tag, then | |
372 | * punt to the requeue list. Requeue will re-invoke us from a context | |
373 | * that's safe to block from. | |
374 | */ | |
375 | static void blk_mq_sched_insert_flush(struct blk_mq_hw_ctx *hctx, | |
376 | struct request *rq, bool can_block) | |
377 | { | |
378 | if (blk_mq_get_driver_tag(rq, &hctx, can_block)) { | |
379 | blk_insert_flush(rq); | |
380 | blk_mq_run_hw_queue(hctx, true); | |
381 | } else | |
c7a571b4 | 382 | blk_mq_add_to_requeue_list(rq, false, true); |
bd6737f1 JA |
383 | } |
384 | ||
385 | void blk_mq_sched_insert_request(struct request *rq, bool at_head, | |
386 | bool run_queue, bool async, bool can_block) | |
387 | { | |
388 | struct request_queue *q = rq->q; | |
389 | struct elevator_queue *e = q->elevator; | |
390 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
391 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); | |
392 | ||
f3a8ab7d | 393 | if (rq->tag == -1 && op_is_flush(rq->cmd_flags)) { |
bd6737f1 JA |
394 | blk_mq_sched_insert_flush(hctx, rq, can_block); |
395 | return; | |
396 | } | |
397 | ||
0cacba6c OS |
398 | if (e && blk_mq_sched_bypass_insert(hctx, rq)) |
399 | goto run; | |
400 | ||
bd6737f1 JA |
401 | if (e && e->type->ops.mq.insert_requests) { |
402 | LIST_HEAD(list); | |
403 | ||
404 | list_add(&rq->queuelist, &list); | |
405 | e->type->ops.mq.insert_requests(hctx, &list, at_head); | |
406 | } else { | |
407 | spin_lock(&ctx->lock); | |
408 | __blk_mq_insert_request(hctx, rq, at_head); | |
409 | spin_unlock(&ctx->lock); | |
410 | } | |
411 | ||
0cacba6c | 412 | run: |
bd6737f1 JA |
413 | if (run_queue) |
414 | blk_mq_run_hw_queue(hctx, async); | |
415 | } | |
416 | ||
417 | void blk_mq_sched_insert_requests(struct request_queue *q, | |
418 | struct blk_mq_ctx *ctx, | |
419 | struct list_head *list, bool run_queue_async) | |
420 | { | |
421 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); | |
422 | struct elevator_queue *e = hctx->queue->elevator; | |
423 | ||
0cacba6c OS |
424 | if (e) { |
425 | struct request *rq, *next; | |
426 | ||
427 | /* | |
428 | * We bypass requests that already have a driver tag assigned, | |
429 | * which should only be flushes. Flushes are only ever inserted | |
430 | * as single requests, so we shouldn't ever hit the | |
431 | * WARN_ON_ONCE() below (but let's handle it just in case). | |
432 | */ | |
433 | list_for_each_entry_safe(rq, next, list, queuelist) { | |
434 | if (WARN_ON_ONCE(rq->tag != -1)) { | |
435 | list_del_init(&rq->queuelist); | |
436 | blk_mq_sched_bypass_insert(hctx, rq); | |
437 | } | |
438 | } | |
439 | } | |
440 | ||
bd6737f1 JA |
441 | if (e && e->type->ops.mq.insert_requests) |
442 | e->type->ops.mq.insert_requests(hctx, list, false); | |
443 | else | |
444 | blk_mq_insert_requests(hctx, ctx, list); | |
445 | ||
446 | blk_mq_run_hw_queue(hctx, run_queue_async); | |
447 | } | |
448 | ||
bd166ef1 JA |
449 | static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, |
450 | struct blk_mq_hw_ctx *hctx, | |
451 | unsigned int hctx_idx) | |
452 | { | |
453 | if (hctx->sched_tags) { | |
454 | blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx); | |
455 | blk_mq_free_rq_map(hctx->sched_tags); | |
456 | hctx->sched_tags = NULL; | |
457 | } | |
458 | } | |
459 | ||
6917ff0b OS |
460 | static int blk_mq_sched_alloc_tags(struct request_queue *q, |
461 | struct blk_mq_hw_ctx *hctx, | |
462 | unsigned int hctx_idx) | |
463 | { | |
464 | struct blk_mq_tag_set *set = q->tag_set; | |
465 | int ret; | |
466 | ||
467 | hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests, | |
468 | set->reserved_tags); | |
469 | if (!hctx->sched_tags) | |
470 | return -ENOMEM; | |
471 | ||
472 | ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests); | |
473 | if (ret) | |
474 | blk_mq_sched_free_tags(set, hctx, hctx_idx); | |
475 | ||
476 | return ret; | |
477 | } | |
478 | ||
54d5329d | 479 | static void blk_mq_sched_tags_teardown(struct request_queue *q) |
bd166ef1 JA |
480 | { |
481 | struct blk_mq_tag_set *set = q->tag_set; | |
482 | struct blk_mq_hw_ctx *hctx; | |
6917ff0b OS |
483 | int i; |
484 | ||
485 | queue_for_each_hw_ctx(q, hctx, i) | |
486 | blk_mq_sched_free_tags(set, hctx, i); | |
487 | } | |
488 | ||
93252632 OS |
489 | int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, |
490 | unsigned int hctx_idx) | |
491 | { | |
492 | struct elevator_queue *e = q->elevator; | |
ee056f98 | 493 | int ret; |
93252632 OS |
494 | |
495 | if (!e) | |
496 | return 0; | |
497 | ||
ee056f98 OS |
498 | ret = blk_mq_sched_alloc_tags(q, hctx, hctx_idx); |
499 | if (ret) | |
500 | return ret; | |
501 | ||
502 | if (e->type->ops.mq.init_hctx) { | |
503 | ret = e->type->ops.mq.init_hctx(hctx, hctx_idx); | |
504 | if (ret) { | |
505 | blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx); | |
506 | return ret; | |
507 | } | |
508 | } | |
509 | ||
d332ce09 OS |
510 | blk_mq_debugfs_register_sched_hctx(q, hctx); |
511 | ||
ee056f98 | 512 | return 0; |
93252632 OS |
513 | } |
514 | ||
515 | void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, | |
516 | unsigned int hctx_idx) | |
517 | { | |
518 | struct elevator_queue *e = q->elevator; | |
519 | ||
520 | if (!e) | |
521 | return; | |
522 | ||
d332ce09 OS |
523 | blk_mq_debugfs_unregister_sched_hctx(hctx); |
524 | ||
ee056f98 OS |
525 | if (e->type->ops.mq.exit_hctx && hctx->sched_data) { |
526 | e->type->ops.mq.exit_hctx(hctx, hctx_idx); | |
527 | hctx->sched_data = NULL; | |
528 | } | |
529 | ||
93252632 OS |
530 | blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx); |
531 | } | |
532 | ||
6917ff0b OS |
533 | int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) |
534 | { | |
535 | struct blk_mq_hw_ctx *hctx; | |
ee056f98 | 536 | struct elevator_queue *eq; |
6917ff0b OS |
537 | unsigned int i; |
538 | int ret; | |
539 | ||
540 | if (!e) { | |
541 | q->elevator = NULL; | |
542 | return 0; | |
543 | } | |
bd166ef1 JA |
544 | |
545 | /* | |
546 | * Default to 256, since we don't split into sync/async like the | |
547 | * old code did. Additionally, this is a per-hw queue depth. | |
548 | */ | |
549 | q->nr_requests = 2 * BLKDEV_MAX_RQ; | |
550 | ||
bd166ef1 | 551 | queue_for_each_hw_ctx(q, hctx, i) { |
6917ff0b | 552 | ret = blk_mq_sched_alloc_tags(q, hctx, i); |
bd166ef1 | 553 | if (ret) |
6917ff0b | 554 | goto err; |
bd166ef1 JA |
555 | } |
556 | ||
6917ff0b OS |
557 | ret = e->ops.mq.init_sched(q, e); |
558 | if (ret) | |
559 | goto err; | |
bd166ef1 | 560 | |
d332ce09 OS |
561 | blk_mq_debugfs_register_sched(q); |
562 | ||
563 | queue_for_each_hw_ctx(q, hctx, i) { | |
564 | if (e->ops.mq.init_hctx) { | |
ee056f98 OS |
565 | ret = e->ops.mq.init_hctx(hctx, i); |
566 | if (ret) { | |
567 | eq = q->elevator; | |
568 | blk_mq_exit_sched(q, eq); | |
569 | kobject_put(&eq->kobj); | |
570 | return ret; | |
571 | } | |
572 | } | |
d332ce09 | 573 | blk_mq_debugfs_register_sched_hctx(q, hctx); |
ee056f98 OS |
574 | } |
575 | ||
bd166ef1 | 576 | return 0; |
bd166ef1 | 577 | |
6917ff0b | 578 | err: |
54d5329d OS |
579 | blk_mq_sched_tags_teardown(q); |
580 | q->elevator = NULL; | |
6917ff0b | 581 | return ret; |
bd166ef1 | 582 | } |
d3484991 | 583 | |
54d5329d OS |
584 | void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e) |
585 | { | |
ee056f98 OS |
586 | struct blk_mq_hw_ctx *hctx; |
587 | unsigned int i; | |
588 | ||
d332ce09 OS |
589 | queue_for_each_hw_ctx(q, hctx, i) { |
590 | blk_mq_debugfs_unregister_sched_hctx(hctx); | |
591 | if (e->type->ops.mq.exit_hctx && hctx->sched_data) { | |
592 | e->type->ops.mq.exit_hctx(hctx, i); | |
593 | hctx->sched_data = NULL; | |
ee056f98 OS |
594 | } |
595 | } | |
d332ce09 | 596 | blk_mq_debugfs_unregister_sched(q); |
54d5329d OS |
597 | if (e->type->ops.mq.exit_sched) |
598 | e->type->ops.mq.exit_sched(e); | |
599 | blk_mq_sched_tags_teardown(q); | |
600 | q->elevator = NULL; | |
601 | } | |
602 | ||
d3484991 JA |
603 | int blk_mq_sched_init(struct request_queue *q) |
604 | { | |
605 | int ret; | |
606 | ||
d3484991 JA |
607 | mutex_lock(&q->sysfs_lock); |
608 | ret = elevator_init(q, NULL); | |
609 | mutex_unlock(&q->sysfs_lock); | |
610 | ||
611 | return ret; | |
612 | } |