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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 | ||
44e8c2bf | 34 | void blk_mq_sched_assign_ioc(struct request *rq, struct bio *bio) |
bd166ef1 | 35 | { |
44e8c2bf CH |
36 | struct request_queue *q = rq->q; |
37 | struct io_context *ioc = rq_ioc(bio); | |
bd166ef1 JA |
38 | struct io_cq *icq; |
39 | ||
40 | spin_lock_irq(q->queue_lock); | |
41 | icq = ioc_lookup_icq(ioc, q); | |
42 | spin_unlock_irq(q->queue_lock); | |
43 | ||
44 | if (!icq) { | |
45 | icq = ioc_create_icq(ioc, q, GFP_ATOMIC); | |
46 | if (!icq) | |
47 | return; | |
48 | } | |
ea511e3c | 49 | get_io_context(icq->ioc); |
44e8c2bf | 50 | rq->elv.icq = icq; |
bd166ef1 JA |
51 | } |
52 | ||
8e8320c9 JA |
53 | /* |
54 | * Mark a hardware queue as needing a restart. For shared queues, maintain | |
55 | * a count of how many hardware queues are marked for restart. | |
56 | */ | |
57 | static void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx) | |
58 | { | |
59 | if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) | |
60 | return; | |
61 | ||
62 | if (hctx->flags & BLK_MQ_F_TAG_SHARED) { | |
63 | struct request_queue *q = hctx->queue; | |
64 | ||
65 | if (!test_and_set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) | |
66 | atomic_inc(&q->shared_hctx_restart); | |
67 | } else | |
68 | set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); | |
69 | } | |
70 | ||
358a3a6b | 71 | void blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx) |
8e8320c9 JA |
72 | { |
73 | if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) | |
358a3a6b | 74 | return; |
8e8320c9 | 75 | |
358a3a6b | 76 | clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); |
8e8320c9 JA |
77 | |
78 | if (blk_mq_hctx_has_pending(hctx)) { | |
79 | blk_mq_run_hw_queue(hctx, true); | |
358a3a6b | 80 | return; |
8e8320c9 | 81 | } |
8e8320c9 JA |
82 | } |
83 | ||
1f460b63 ML |
84 | /* |
85 | * Only SCSI implements .get_budget and .put_budget, and SCSI restarts | |
86 | * its queue by itself in its completion handler, so we don't need to | |
87 | * restart queue if .get_budget() returns BLK_STS_NO_RESOURCE. | |
88 | */ | |
89 | static void blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) | |
caf8eb0d ML |
90 | { |
91 | struct request_queue *q = hctx->queue; | |
92 | struct elevator_queue *e = q->elevator; | |
93 | LIST_HEAD(rq_list); | |
94 | ||
95 | do { | |
de148297 | 96 | struct request *rq; |
caf8eb0d | 97 | |
de148297 ML |
98 | if (e->type->ops.mq.has_work && |
99 | !e->type->ops.mq.has_work(hctx)) | |
caf8eb0d | 100 | break; |
de148297 | 101 | |
88022d72 | 102 | if (!blk_mq_get_dispatch_budget(hctx)) |
1f460b63 | 103 | break; |
de148297 ML |
104 | |
105 | rq = e->type->ops.mq.dispatch_request(hctx); | |
106 | if (!rq) { | |
107 | blk_mq_put_dispatch_budget(hctx); | |
108 | break; | |
de148297 ML |
109 | } |
110 | ||
111 | /* | |
112 | * Now this rq owns the budget which has to be released | |
113 | * if this rq won't be queued to driver via .queue_rq() | |
114 | * in blk_mq_dispatch_rq_list(). | |
115 | */ | |
caf8eb0d | 116 | list_add(&rq->queuelist, &rq_list); |
de148297 | 117 | } while (blk_mq_dispatch_rq_list(q, &rq_list, true)); |
caf8eb0d ML |
118 | } |
119 | ||
b347689f ML |
120 | static struct blk_mq_ctx *blk_mq_next_ctx(struct blk_mq_hw_ctx *hctx, |
121 | struct blk_mq_ctx *ctx) | |
122 | { | |
123 | unsigned idx = ctx->index_hw; | |
124 | ||
125 | if (++idx == hctx->nr_ctx) | |
126 | idx = 0; | |
127 | ||
128 | return hctx->ctxs[idx]; | |
129 | } | |
130 | ||
1f460b63 ML |
131 | /* |
132 | * Only SCSI implements .get_budget and .put_budget, and SCSI restarts | |
133 | * its queue by itself in its completion handler, so we don't need to | |
134 | * restart queue if .get_budget() returns BLK_STS_NO_RESOURCE. | |
135 | */ | |
136 | static void blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) | |
b347689f ML |
137 | { |
138 | struct request_queue *q = hctx->queue; | |
139 | LIST_HEAD(rq_list); | |
140 | struct blk_mq_ctx *ctx = READ_ONCE(hctx->dispatch_from); | |
141 | ||
142 | do { | |
143 | struct request *rq; | |
b347689f ML |
144 | |
145 | if (!sbitmap_any_bit_set(&hctx->ctx_map)) | |
146 | break; | |
147 | ||
88022d72 | 148 | if (!blk_mq_get_dispatch_budget(hctx)) |
1f460b63 | 149 | break; |
b347689f ML |
150 | |
151 | rq = blk_mq_dequeue_from_ctx(hctx, ctx); | |
152 | if (!rq) { | |
153 | blk_mq_put_dispatch_budget(hctx); | |
154 | break; | |
b347689f ML |
155 | } |
156 | ||
157 | /* | |
158 | * Now this rq owns the budget which has to be released | |
159 | * if this rq won't be queued to driver via .queue_rq() | |
160 | * in blk_mq_dispatch_rq_list(). | |
161 | */ | |
162 | list_add(&rq->queuelist, &rq_list); | |
163 | ||
164 | /* round robin for fair dispatch */ | |
165 | ctx = blk_mq_next_ctx(hctx, rq->mq_ctx); | |
166 | ||
167 | } while (blk_mq_dispatch_rq_list(q, &rq_list, true)); | |
168 | ||
169 | WRITE_ONCE(hctx->dispatch_from, ctx); | |
b347689f ML |
170 | } |
171 | ||
de148297 | 172 | /* return true if hw queue need to be run again */ |
1f460b63 | 173 | void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) |
bd166ef1 | 174 | { |
81380ca1 OS |
175 | struct request_queue *q = hctx->queue; |
176 | struct elevator_queue *e = q->elevator; | |
64765a75 | 177 | const bool has_sched_dispatch = e && e->type->ops.mq.dispatch_request; |
bd166ef1 JA |
178 | LIST_HEAD(rq_list); |
179 | ||
f4560ffe ML |
180 | /* RCU or SRCU read lock is needed before checking quiesced flag */ |
181 | if (unlikely(blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q))) | |
1f460b63 | 182 | return; |
bd166ef1 JA |
183 | |
184 | hctx->run++; | |
185 | ||
186 | /* | |
187 | * If we have previous entries on our dispatch list, grab them first for | |
188 | * more fair dispatch. | |
189 | */ | |
190 | if (!list_empty_careful(&hctx->dispatch)) { | |
191 | spin_lock(&hctx->lock); | |
192 | if (!list_empty(&hctx->dispatch)) | |
193 | list_splice_init(&hctx->dispatch, &rq_list); | |
194 | spin_unlock(&hctx->lock); | |
195 | } | |
196 | ||
197 | /* | |
198 | * Only ask the scheduler for requests, if we didn't have residual | |
199 | * requests from the dispatch list. This is to avoid the case where | |
200 | * we only ever dispatch a fraction of the requests available because | |
201 | * of low device queue depth. Once we pull requests out of the IO | |
202 | * scheduler, we can no longer merge or sort them. So it's best to | |
203 | * leave them there for as long as we can. Mark the hw queue as | |
204 | * needing a restart in that case. | |
caf8eb0d ML |
205 | * |
206 | * We want to dispatch from the scheduler if there was nothing | |
207 | * on the dispatch list or we were able to dispatch from the | |
208 | * dispatch list. | |
bd166ef1 | 209 | */ |
c13660a0 | 210 | if (!list_empty(&rq_list)) { |
d38d3515 | 211 | blk_mq_sched_mark_restart_hctx(hctx); |
b347689f ML |
212 | if (blk_mq_dispatch_rq_list(q, &rq_list, false)) { |
213 | if (has_sched_dispatch) | |
1f460b63 | 214 | blk_mq_do_dispatch_sched(hctx); |
b347689f | 215 | else |
1f460b63 | 216 | blk_mq_do_dispatch_ctx(hctx); |
b347689f | 217 | } |
caf8eb0d | 218 | } else if (has_sched_dispatch) { |
1f460b63 | 219 | blk_mq_do_dispatch_sched(hctx); |
b347689f ML |
220 | } else if (q->mq_ops->get_budget) { |
221 | /* | |
222 | * If we need to get budget before queuing request, we | |
223 | * dequeue request one by one from sw queue for avoiding | |
224 | * to mess up I/O merge when dispatch runs out of resource. | |
225 | * | |
226 | * TODO: get more budgets, and dequeue more requests in | |
227 | * one time. | |
228 | */ | |
1f460b63 | 229 | blk_mq_do_dispatch_ctx(hctx); |
caf8eb0d | 230 | } else { |
c13660a0 | 231 | blk_mq_flush_busy_ctxs(hctx, &rq_list); |
de148297 | 232 | blk_mq_dispatch_rq_list(q, &rq_list, false); |
64765a75 | 233 | } |
bd166ef1 JA |
234 | } |
235 | ||
e4d750c9 JA |
236 | bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, |
237 | struct request **merged_request) | |
bd166ef1 JA |
238 | { |
239 | struct request *rq; | |
bd166ef1 | 240 | |
34fe7c05 CH |
241 | switch (elv_merge(q, &rq, bio)) { |
242 | case ELEVATOR_BACK_MERGE: | |
bd166ef1 JA |
243 | if (!blk_mq_sched_allow_merge(q, rq, bio)) |
244 | return false; | |
34fe7c05 CH |
245 | if (!bio_attempt_back_merge(q, rq, bio)) |
246 | return false; | |
247 | *merged_request = attempt_back_merge(q, rq); | |
248 | if (!*merged_request) | |
249 | elv_merged_request(q, rq, ELEVATOR_BACK_MERGE); | |
250 | return true; | |
251 | case ELEVATOR_FRONT_MERGE: | |
bd166ef1 JA |
252 | if (!blk_mq_sched_allow_merge(q, rq, bio)) |
253 | return false; | |
34fe7c05 CH |
254 | if (!bio_attempt_front_merge(q, rq, bio)) |
255 | return false; | |
256 | *merged_request = attempt_front_merge(q, rq); | |
257 | if (!*merged_request) | |
258 | elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE); | |
259 | return true; | |
260 | default: | |
261 | return false; | |
bd166ef1 | 262 | } |
bd166ef1 JA |
263 | } |
264 | EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); | |
265 | ||
9bddeb2a ML |
266 | /* |
267 | * Reverse check our software queue for entries that we could potentially | |
268 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend | |
269 | * too much time checking for merges. | |
270 | */ | |
271 | static bool blk_mq_attempt_merge(struct request_queue *q, | |
272 | struct blk_mq_ctx *ctx, struct bio *bio) | |
273 | { | |
274 | struct request *rq; | |
275 | int checked = 8; | |
276 | ||
7b607814 BVA |
277 | lockdep_assert_held(&ctx->lock); |
278 | ||
9bddeb2a ML |
279 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { |
280 | bool merged = false; | |
281 | ||
282 | if (!checked--) | |
283 | break; | |
284 | ||
285 | if (!blk_rq_merge_ok(rq, bio)) | |
286 | continue; | |
287 | ||
288 | switch (blk_try_merge(rq, bio)) { | |
289 | case ELEVATOR_BACK_MERGE: | |
290 | if (blk_mq_sched_allow_merge(q, rq, bio)) | |
291 | merged = bio_attempt_back_merge(q, rq, bio); | |
292 | break; | |
293 | case ELEVATOR_FRONT_MERGE: | |
294 | if (blk_mq_sched_allow_merge(q, rq, bio)) | |
295 | merged = bio_attempt_front_merge(q, rq, bio); | |
296 | break; | |
297 | case ELEVATOR_DISCARD_MERGE: | |
298 | merged = bio_attempt_discard_merge(q, rq, bio); | |
299 | break; | |
300 | default: | |
301 | continue; | |
302 | } | |
303 | ||
304 | if (merged) | |
305 | ctx->rq_merged++; | |
306 | return merged; | |
307 | } | |
308 | ||
309 | return false; | |
310 | } | |
311 | ||
bd166ef1 JA |
312 | bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) |
313 | { | |
314 | struct elevator_queue *e = q->elevator; | |
9bddeb2a ML |
315 | struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); |
316 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); | |
317 | bool ret = false; | |
bd166ef1 | 318 | |
9bddeb2a | 319 | if (e && e->type->ops.mq.bio_merge) { |
bd166ef1 JA |
320 | blk_mq_put_ctx(ctx); |
321 | return e->type->ops.mq.bio_merge(hctx, bio); | |
322 | } | |
323 | ||
9bddeb2a ML |
324 | if (hctx->flags & BLK_MQ_F_SHOULD_MERGE) { |
325 | /* default per sw-queue merge */ | |
326 | spin_lock(&ctx->lock); | |
327 | ret = blk_mq_attempt_merge(q, ctx, bio); | |
328 | spin_unlock(&ctx->lock); | |
329 | } | |
330 | ||
331 | blk_mq_put_ctx(ctx); | |
332 | return ret; | |
bd166ef1 JA |
333 | } |
334 | ||
335 | bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq) | |
336 | { | |
337 | return rq_mergeable(rq) && elv_attempt_insert_merge(q, rq); | |
338 | } | |
339 | EXPORT_SYMBOL_GPL(blk_mq_sched_try_insert_merge); | |
340 | ||
341 | void blk_mq_sched_request_inserted(struct request *rq) | |
342 | { | |
343 | trace_block_rq_insert(rq->q, rq); | |
344 | } | |
345 | EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted); | |
346 | ||
0cacba6c OS |
347 | static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, |
348 | struct request *rq) | |
bd166ef1 JA |
349 | { |
350 | if (rq->tag == -1) { | |
351 | rq->rq_flags |= RQF_SORTED; | |
352 | return false; | |
353 | } | |
354 | ||
355 | /* | |
356 | * If we already have a real request tag, send directly to | |
357 | * the dispatch list. | |
358 | */ | |
359 | spin_lock(&hctx->lock); | |
360 | list_add(&rq->queuelist, &hctx->dispatch); | |
361 | spin_unlock(&hctx->lock); | |
362 | return true; | |
363 | } | |
bd166ef1 | 364 | |
bd6737f1 JA |
365 | /* |
366 | * Add flush/fua to the queue. If we fail getting a driver tag, then | |
367 | * punt to the requeue list. Requeue will re-invoke us from a context | |
368 | * that's safe to block from. | |
369 | */ | |
370 | static void blk_mq_sched_insert_flush(struct blk_mq_hw_ctx *hctx, | |
371 | struct request *rq, bool can_block) | |
372 | { | |
373 | if (blk_mq_get_driver_tag(rq, &hctx, can_block)) { | |
374 | blk_insert_flush(rq); | |
375 | blk_mq_run_hw_queue(hctx, true); | |
376 | } else | |
c7a571b4 | 377 | blk_mq_add_to_requeue_list(rq, false, true); |
bd6737f1 JA |
378 | } |
379 | ||
380 | void blk_mq_sched_insert_request(struct request *rq, bool at_head, | |
381 | bool run_queue, bool async, bool can_block) | |
382 | { | |
383 | struct request_queue *q = rq->q; | |
384 | struct elevator_queue *e = q->elevator; | |
385 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
386 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); | |
387 | ||
f3a8ab7d | 388 | if (rq->tag == -1 && op_is_flush(rq->cmd_flags)) { |
bd6737f1 JA |
389 | blk_mq_sched_insert_flush(hctx, rq, can_block); |
390 | return; | |
391 | } | |
392 | ||
0cacba6c OS |
393 | if (e && blk_mq_sched_bypass_insert(hctx, rq)) |
394 | goto run; | |
395 | ||
bd6737f1 JA |
396 | if (e && e->type->ops.mq.insert_requests) { |
397 | LIST_HEAD(list); | |
398 | ||
399 | list_add(&rq->queuelist, &list); | |
400 | e->type->ops.mq.insert_requests(hctx, &list, at_head); | |
401 | } else { | |
402 | spin_lock(&ctx->lock); | |
403 | __blk_mq_insert_request(hctx, rq, at_head); | |
404 | spin_unlock(&ctx->lock); | |
405 | } | |
406 | ||
0cacba6c | 407 | run: |
bd6737f1 JA |
408 | if (run_queue) |
409 | blk_mq_run_hw_queue(hctx, async); | |
410 | } | |
411 | ||
412 | void blk_mq_sched_insert_requests(struct request_queue *q, | |
413 | struct blk_mq_ctx *ctx, | |
414 | struct list_head *list, bool run_queue_async) | |
415 | { | |
416 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); | |
417 | struct elevator_queue *e = hctx->queue->elevator; | |
418 | ||
0cacba6c OS |
419 | if (e) { |
420 | struct request *rq, *next; | |
421 | ||
422 | /* | |
423 | * We bypass requests that already have a driver tag assigned, | |
424 | * which should only be flushes. Flushes are only ever inserted | |
425 | * as single requests, so we shouldn't ever hit the | |
426 | * WARN_ON_ONCE() below (but let's handle it just in case). | |
427 | */ | |
428 | list_for_each_entry_safe(rq, next, list, queuelist) { | |
429 | if (WARN_ON_ONCE(rq->tag != -1)) { | |
430 | list_del_init(&rq->queuelist); | |
431 | blk_mq_sched_bypass_insert(hctx, rq); | |
432 | } | |
433 | } | |
434 | } | |
435 | ||
bd6737f1 JA |
436 | if (e && e->type->ops.mq.insert_requests) |
437 | e->type->ops.mq.insert_requests(hctx, list, false); | |
438 | else | |
439 | blk_mq_insert_requests(hctx, ctx, list); | |
440 | ||
441 | blk_mq_run_hw_queue(hctx, run_queue_async); | |
442 | } | |
443 | ||
bd166ef1 JA |
444 | static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, |
445 | struct blk_mq_hw_ctx *hctx, | |
446 | unsigned int hctx_idx) | |
447 | { | |
448 | if (hctx->sched_tags) { | |
449 | blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx); | |
450 | blk_mq_free_rq_map(hctx->sched_tags); | |
451 | hctx->sched_tags = NULL; | |
452 | } | |
453 | } | |
454 | ||
6917ff0b OS |
455 | static int blk_mq_sched_alloc_tags(struct request_queue *q, |
456 | struct blk_mq_hw_ctx *hctx, | |
457 | unsigned int hctx_idx) | |
458 | { | |
459 | struct blk_mq_tag_set *set = q->tag_set; | |
460 | int ret; | |
461 | ||
462 | hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests, | |
463 | set->reserved_tags); | |
464 | if (!hctx->sched_tags) | |
465 | return -ENOMEM; | |
466 | ||
467 | ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests); | |
468 | if (ret) | |
469 | blk_mq_sched_free_tags(set, hctx, hctx_idx); | |
470 | ||
471 | return ret; | |
472 | } | |
473 | ||
54d5329d | 474 | static void blk_mq_sched_tags_teardown(struct request_queue *q) |
bd166ef1 JA |
475 | { |
476 | struct blk_mq_tag_set *set = q->tag_set; | |
477 | struct blk_mq_hw_ctx *hctx; | |
6917ff0b OS |
478 | int i; |
479 | ||
480 | queue_for_each_hw_ctx(q, hctx, i) | |
481 | blk_mq_sched_free_tags(set, hctx, i); | |
482 | } | |
483 | ||
93252632 OS |
484 | int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, |
485 | unsigned int hctx_idx) | |
486 | { | |
487 | struct elevator_queue *e = q->elevator; | |
ee056f98 | 488 | int ret; |
93252632 OS |
489 | |
490 | if (!e) | |
491 | return 0; | |
492 | ||
ee056f98 OS |
493 | ret = blk_mq_sched_alloc_tags(q, hctx, hctx_idx); |
494 | if (ret) | |
495 | return ret; | |
496 | ||
497 | if (e->type->ops.mq.init_hctx) { | |
498 | ret = e->type->ops.mq.init_hctx(hctx, hctx_idx); | |
499 | if (ret) { | |
500 | blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx); | |
501 | return ret; | |
502 | } | |
503 | } | |
504 | ||
d332ce09 OS |
505 | blk_mq_debugfs_register_sched_hctx(q, hctx); |
506 | ||
ee056f98 | 507 | return 0; |
93252632 OS |
508 | } |
509 | ||
510 | void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, | |
511 | unsigned int hctx_idx) | |
512 | { | |
513 | struct elevator_queue *e = q->elevator; | |
514 | ||
515 | if (!e) | |
516 | return; | |
517 | ||
d332ce09 OS |
518 | blk_mq_debugfs_unregister_sched_hctx(hctx); |
519 | ||
ee056f98 OS |
520 | if (e->type->ops.mq.exit_hctx && hctx->sched_data) { |
521 | e->type->ops.mq.exit_hctx(hctx, hctx_idx); | |
522 | hctx->sched_data = NULL; | |
523 | } | |
524 | ||
93252632 OS |
525 | blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx); |
526 | } | |
527 | ||
6917ff0b OS |
528 | int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) |
529 | { | |
530 | struct blk_mq_hw_ctx *hctx; | |
ee056f98 | 531 | struct elevator_queue *eq; |
6917ff0b OS |
532 | unsigned int i; |
533 | int ret; | |
534 | ||
535 | if (!e) { | |
536 | q->elevator = NULL; | |
537 | return 0; | |
538 | } | |
bd166ef1 JA |
539 | |
540 | /* | |
32825c45 ML |
541 | * Default to double of smaller one between hw queue_depth and 128, |
542 | * since we don't split into sync/async like the old code did. | |
543 | * Additionally, this is a per-hw queue depth. | |
bd166ef1 | 544 | */ |
32825c45 ML |
545 | q->nr_requests = 2 * min_t(unsigned int, q->tag_set->queue_depth, |
546 | BLKDEV_MAX_RQ); | |
bd166ef1 | 547 | |
bd166ef1 | 548 | queue_for_each_hw_ctx(q, hctx, i) { |
6917ff0b | 549 | ret = blk_mq_sched_alloc_tags(q, hctx, i); |
bd166ef1 | 550 | if (ret) |
6917ff0b | 551 | goto err; |
bd166ef1 JA |
552 | } |
553 | ||
6917ff0b OS |
554 | ret = e->ops.mq.init_sched(q, e); |
555 | if (ret) | |
556 | goto err; | |
bd166ef1 | 557 | |
d332ce09 OS |
558 | blk_mq_debugfs_register_sched(q); |
559 | ||
560 | queue_for_each_hw_ctx(q, hctx, i) { | |
561 | if (e->ops.mq.init_hctx) { | |
ee056f98 OS |
562 | ret = e->ops.mq.init_hctx(hctx, i); |
563 | if (ret) { | |
564 | eq = q->elevator; | |
565 | blk_mq_exit_sched(q, eq); | |
566 | kobject_put(&eq->kobj); | |
567 | return ret; | |
568 | } | |
569 | } | |
d332ce09 | 570 | blk_mq_debugfs_register_sched_hctx(q, hctx); |
ee056f98 OS |
571 | } |
572 | ||
bd166ef1 | 573 | return 0; |
bd166ef1 | 574 | |
6917ff0b | 575 | err: |
54d5329d OS |
576 | blk_mq_sched_tags_teardown(q); |
577 | q->elevator = NULL; | |
6917ff0b | 578 | return ret; |
bd166ef1 | 579 | } |
d3484991 | 580 | |
54d5329d OS |
581 | void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e) |
582 | { | |
ee056f98 OS |
583 | struct blk_mq_hw_ctx *hctx; |
584 | unsigned int i; | |
585 | ||
d332ce09 OS |
586 | queue_for_each_hw_ctx(q, hctx, i) { |
587 | blk_mq_debugfs_unregister_sched_hctx(hctx); | |
588 | if (e->type->ops.mq.exit_hctx && hctx->sched_data) { | |
589 | e->type->ops.mq.exit_hctx(hctx, i); | |
590 | hctx->sched_data = NULL; | |
ee056f98 OS |
591 | } |
592 | } | |
d332ce09 | 593 | blk_mq_debugfs_unregister_sched(q); |
54d5329d OS |
594 | if (e->type->ops.mq.exit_sched) |
595 | e->type->ops.mq.exit_sched(e); | |
596 | blk_mq_sched_tags_teardown(q); | |
597 | q->elevator = NULL; | |
598 | } | |
599 | ||
d3484991 JA |
600 | int blk_mq_sched_init(struct request_queue *q) |
601 | { | |
602 | int ret; | |
603 | ||
d3484991 JA |
604 | mutex_lock(&q->sysfs_lock); |
605 | ret = elevator_init(q, NULL); | |
606 | mutex_unlock(&q->sysfs_lock); | |
607 | ||
608 | return ret; | |
609 | } |