Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * MQ Deadline i/o scheduler - adaptation of the legacy deadline scheduler,
4 : * for the blk-mq scheduling framework
5 : *
6 : * Copyright (C) 2016 Jens Axboe <axboe@kernel.dk>
7 : */
8 : #include <linux/kernel.h>
9 : #include <linux/fs.h>
10 : #include <linux/blkdev.h>
11 : #include <linux/bio.h>
12 : #include <linux/module.h>
13 : #include <linux/slab.h>
14 : #include <linux/init.h>
15 : #include <linux/compiler.h>
16 : #include <linux/rbtree.h>
17 : #include <linux/sbitmap.h>
18 :
19 : #include <trace/events/block.h>
20 :
21 : #include "elevator.h"
22 : #include "blk.h"
23 : #include "blk-mq.h"
24 : #include "blk-mq-debugfs.h"
25 : #include "blk-mq-sched.h"
26 :
27 : /*
28 : * See Documentation/block/deadline-iosched.rst
29 : */
30 : static const int read_expire = HZ / 2; /* max time before a read is submitted. */
31 : static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
32 : /*
33 : * Time after which to dispatch lower priority requests even if higher
34 : * priority requests are pending.
35 : */
36 : static const int prio_aging_expire = 10 * HZ;
37 : static const int writes_starved = 2; /* max times reads can starve a write */
38 : static const int fifo_batch = 16; /* # of sequential requests treated as one
39 : by the above parameters. For throughput. */
40 :
41 : enum dd_data_dir {
42 : DD_READ = READ,
43 : DD_WRITE = WRITE,
44 : };
45 :
46 : enum { DD_DIR_COUNT = 2 };
47 :
48 : enum dd_prio {
49 : DD_RT_PRIO = 0,
50 : DD_BE_PRIO = 1,
51 : DD_IDLE_PRIO = 2,
52 : DD_PRIO_MAX = 2,
53 : };
54 :
55 : enum { DD_PRIO_COUNT = 3 };
56 :
57 : /*
58 : * I/O statistics per I/O priority. It is fine if these counters overflow.
59 : * What matters is that these counters are at least as wide as
60 : * log2(max_outstanding_requests).
61 : */
62 : struct io_stats_per_prio {
63 : uint32_t inserted;
64 : uint32_t merged;
65 : uint32_t dispatched;
66 : atomic_t completed;
67 : };
68 :
69 : /*
70 : * Deadline scheduler data per I/O priority (enum dd_prio). Requests are
71 : * present on both sort_list[] and fifo_list[].
72 : */
73 : struct dd_per_prio {
74 : struct list_head dispatch;
75 : struct rb_root sort_list[DD_DIR_COUNT];
76 : struct list_head fifo_list[DD_DIR_COUNT];
77 : /* Position of the most recently dispatched request. */
78 : sector_t latest_pos[DD_DIR_COUNT];
79 : struct io_stats_per_prio stats;
80 : };
81 :
82 : struct deadline_data {
83 : /*
84 : * run time data
85 : */
86 :
87 : struct dd_per_prio per_prio[DD_PRIO_COUNT];
88 :
89 : /* Data direction of latest dispatched request. */
90 : enum dd_data_dir last_dir;
91 : unsigned int batching; /* number of sequential requests made */
92 : unsigned int starved; /* times reads have starved writes */
93 :
94 : /*
95 : * settings that change how the i/o scheduler behaves
96 : */
97 : int fifo_expire[DD_DIR_COUNT];
98 : int fifo_batch;
99 : int writes_starved;
100 : int front_merges;
101 : u32 async_depth;
102 : int prio_aging_expire;
103 :
104 : spinlock_t lock;
105 : spinlock_t zone_lock;
106 : };
107 :
108 : /* Maps an I/O priority class to a deadline scheduler priority. */
109 : static const enum dd_prio ioprio_class_to_prio[] = {
110 : [IOPRIO_CLASS_NONE] = DD_BE_PRIO,
111 : [IOPRIO_CLASS_RT] = DD_RT_PRIO,
112 : [IOPRIO_CLASS_BE] = DD_BE_PRIO,
113 : [IOPRIO_CLASS_IDLE] = DD_IDLE_PRIO,
114 : };
115 :
116 : static inline struct rb_root *
117 : deadline_rb_root(struct dd_per_prio *per_prio, struct request *rq)
118 : {
119 0 : return &per_prio->sort_list[rq_data_dir(rq)];
120 : }
121 :
122 : /*
123 : * Returns the I/O priority class (IOPRIO_CLASS_*) that has been assigned to a
124 : * request.
125 : */
126 : static u8 dd_rq_ioclass(struct request *rq)
127 : {
128 0 : return IOPRIO_PRIO_CLASS(req_get_ioprio(rq));
129 : }
130 :
131 : /*
132 : * get the request before `rq' in sector-sorted order
133 : */
134 : static inline struct request *
135 : deadline_earlier_request(struct request *rq)
136 : {
137 : struct rb_node *node = rb_prev(&rq->rb_node);
138 :
139 : if (node)
140 : return rb_entry_rq(node);
141 :
142 : return NULL;
143 : }
144 :
145 : /*
146 : * get the request after `rq' in sector-sorted order
147 : */
148 : static inline struct request *
149 : deadline_latter_request(struct request *rq)
150 : {
151 : struct rb_node *node = rb_next(&rq->rb_node);
152 :
153 : if (node)
154 : return rb_entry_rq(node);
155 :
156 : return NULL;
157 : }
158 :
159 : /*
160 : * Return the first request for which blk_rq_pos() >= @pos. For zoned devices,
161 : * return the first request after the start of the zone containing @pos.
162 : */
163 : static inline struct request *deadline_from_pos(struct dd_per_prio *per_prio,
164 : enum dd_data_dir data_dir, sector_t pos)
165 : {
166 0 : struct rb_node *node = per_prio->sort_list[data_dir].rb_node;
167 0 : struct request *rq, *res = NULL;
168 :
169 0 : if (!node)
170 : return NULL;
171 :
172 : rq = rb_entry_rq(node);
173 : /*
174 : * A zoned write may have been requeued with a starting position that
175 : * is below that of the most recently dispatched request. Hence, for
176 : * zoned writes, start searching from the start of a zone.
177 : */
178 : if (blk_rq_is_seq_zoned_write(rq))
179 : pos = round_down(pos, rq->q->limits.chunk_sectors);
180 :
181 0 : while (node) {
182 0 : rq = rb_entry_rq(node);
183 0 : if (blk_rq_pos(rq) >= pos) {
184 0 : res = rq;
185 0 : node = node->rb_left;
186 : } else {
187 0 : node = node->rb_right;
188 : }
189 : }
190 : return res;
191 : }
192 :
193 : static void
194 : deadline_add_rq_rb(struct dd_per_prio *per_prio, struct request *rq)
195 : {
196 0 : struct rb_root *root = deadline_rb_root(per_prio, rq);
197 :
198 0 : elv_rb_add(root, rq);
199 : }
200 :
201 : static inline void
202 : deadline_del_rq_rb(struct dd_per_prio *per_prio, struct request *rq)
203 : {
204 0 : elv_rb_del(deadline_rb_root(per_prio, rq), rq);
205 : }
206 :
207 : /*
208 : * remove rq from rbtree and fifo.
209 : */
210 0 : static void deadline_remove_request(struct request_queue *q,
211 : struct dd_per_prio *per_prio,
212 : struct request *rq)
213 : {
214 0 : list_del_init(&rq->queuelist);
215 :
216 : /*
217 : * We might not be on the rbtree, if we are doing an insert merge
218 : */
219 0 : if (!RB_EMPTY_NODE(&rq->rb_node))
220 : deadline_del_rq_rb(per_prio, rq);
221 :
222 0 : elv_rqhash_del(q, rq);
223 0 : if (q->last_merge == rq)
224 0 : q->last_merge = NULL;
225 0 : }
226 :
227 0 : static void dd_request_merged(struct request_queue *q, struct request *req,
228 : enum elv_merge type)
229 : {
230 0 : struct deadline_data *dd = q->elevator->elevator_data;
231 0 : const u8 ioprio_class = dd_rq_ioclass(req);
232 0 : const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
233 0 : struct dd_per_prio *per_prio = &dd->per_prio[prio];
234 :
235 : /*
236 : * if the merge was a front merge, we need to reposition request
237 : */
238 0 : if (type == ELEVATOR_FRONT_MERGE) {
239 0 : elv_rb_del(deadline_rb_root(per_prio, req), req);
240 : deadline_add_rq_rb(per_prio, req);
241 : }
242 0 : }
243 :
244 : /*
245 : * Callback function that is invoked after @next has been merged into @req.
246 : */
247 0 : static void dd_merged_requests(struct request_queue *q, struct request *req,
248 : struct request *next)
249 : {
250 0 : struct deadline_data *dd = q->elevator->elevator_data;
251 0 : const u8 ioprio_class = dd_rq_ioclass(next);
252 0 : const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
253 :
254 : lockdep_assert_held(&dd->lock);
255 :
256 0 : dd->per_prio[prio].stats.merged++;
257 :
258 : /*
259 : * if next expires before rq, assign its expire time to rq
260 : * and move into next position (next will be deleted) in fifo
261 : */
262 0 : if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
263 0 : if (time_before((unsigned long)next->fifo_time,
264 : (unsigned long)req->fifo_time)) {
265 0 : list_move(&req->queuelist, &next->queuelist);
266 0 : req->fifo_time = next->fifo_time;
267 : }
268 : }
269 :
270 : /*
271 : * kill knowledge of next, this one is a goner
272 : */
273 0 : deadline_remove_request(q, &dd->per_prio[prio], next);
274 0 : }
275 :
276 : /*
277 : * move an entry to dispatch queue
278 : */
279 : static void
280 : deadline_move_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
281 : struct request *rq)
282 : {
283 : /*
284 : * take it off the sort and fifo list
285 : */
286 0 : deadline_remove_request(rq->q, per_prio, rq);
287 : }
288 :
289 : /* Number of requests queued for a given priority level. */
290 : static u32 dd_queued(struct deadline_data *dd, enum dd_prio prio)
291 : {
292 0 : const struct io_stats_per_prio *stats = &dd->per_prio[prio].stats;
293 :
294 : lockdep_assert_held(&dd->lock);
295 :
296 0 : return stats->inserted - atomic_read(&stats->completed);
297 : }
298 :
299 : /*
300 : * deadline_check_fifo returns true if and only if there are expired requests
301 : * in the FIFO list. Requires !list_empty(&dd->fifo_list[data_dir]).
302 : */
303 : static inline bool deadline_check_fifo(struct dd_per_prio *per_prio,
304 : enum dd_data_dir data_dir)
305 : {
306 0 : struct request *rq = rq_entry_fifo(per_prio->fifo_list[data_dir].next);
307 :
308 0 : return time_is_before_eq_jiffies((unsigned long)rq->fifo_time);
309 : }
310 :
311 : /*
312 : * Check if rq has a sequential request preceding it.
313 : */
314 : static bool deadline_is_seq_write(struct deadline_data *dd, struct request *rq)
315 : {
316 : struct request *prev = deadline_earlier_request(rq);
317 :
318 : if (!prev)
319 : return false;
320 :
321 : return blk_rq_pos(prev) + blk_rq_sectors(prev) == blk_rq_pos(rq);
322 : }
323 :
324 : /*
325 : * Skip all write requests that are sequential from @rq, even if we cross
326 : * a zone boundary.
327 : */
328 : static struct request *deadline_skip_seq_writes(struct deadline_data *dd,
329 : struct request *rq)
330 : {
331 : sector_t pos = blk_rq_pos(rq);
332 :
333 : do {
334 : pos += blk_rq_sectors(rq);
335 : rq = deadline_latter_request(rq);
336 : } while (rq && blk_rq_pos(rq) == pos);
337 :
338 : return rq;
339 : }
340 :
341 : /*
342 : * For the specified data direction, return the next request to
343 : * dispatch using arrival ordered lists.
344 : */
345 : static struct request *
346 : deadline_fifo_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
347 : enum dd_data_dir data_dir)
348 : {
349 : struct request *rq, *rb_rq, *next;
350 : unsigned long flags;
351 :
352 0 : if (list_empty(&per_prio->fifo_list[data_dir]))
353 : return NULL;
354 :
355 0 : rq = rq_entry_fifo(per_prio->fifo_list[data_dir].next);
356 : if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q))
357 : return rq;
358 :
359 : /*
360 : * Look for a write request that can be dispatched, that is one with
361 : * an unlocked target zone. For some HDDs, breaking a sequential
362 : * write stream can lead to lower throughput, so make sure to preserve
363 : * sequential write streams, even if that stream crosses into the next
364 : * zones and these zones are unlocked.
365 : */
366 : spin_lock_irqsave(&dd->zone_lock, flags);
367 : list_for_each_entry_safe(rq, next, &per_prio->fifo_list[DD_WRITE],
368 : queuelist) {
369 : /* Check whether a prior request exists for the same zone. */
370 : rb_rq = deadline_from_pos(per_prio, data_dir, blk_rq_pos(rq));
371 : if (rb_rq && blk_rq_pos(rb_rq) < blk_rq_pos(rq))
372 : rq = rb_rq;
373 : if (blk_req_can_dispatch_to_zone(rq) &&
374 : (blk_queue_nonrot(rq->q) ||
375 : !deadline_is_seq_write(dd, rq)))
376 : goto out;
377 : }
378 : rq = NULL;
379 : out:
380 : spin_unlock_irqrestore(&dd->zone_lock, flags);
381 :
382 : return rq;
383 : }
384 :
385 : /*
386 : * For the specified data direction, return the next request to
387 : * dispatch using sector position sorted lists.
388 : */
389 : static struct request *
390 : deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
391 : enum dd_data_dir data_dir)
392 : {
393 : struct request *rq;
394 : unsigned long flags;
395 :
396 0 : rq = deadline_from_pos(per_prio, data_dir,
397 : per_prio->latest_pos[data_dir]);
398 0 : if (!rq)
399 : return NULL;
400 :
401 : if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q))
402 : return rq;
403 :
404 : /*
405 : * Look for a write request that can be dispatched, that is one with
406 : * an unlocked target zone. For some HDDs, breaking a sequential
407 : * write stream can lead to lower throughput, so make sure to preserve
408 : * sequential write streams, even if that stream crosses into the next
409 : * zones and these zones are unlocked.
410 : */
411 : spin_lock_irqsave(&dd->zone_lock, flags);
412 : while (rq) {
413 : if (blk_req_can_dispatch_to_zone(rq))
414 : break;
415 : if (blk_queue_nonrot(rq->q))
416 : rq = deadline_latter_request(rq);
417 : else
418 : rq = deadline_skip_seq_writes(dd, rq);
419 : }
420 : spin_unlock_irqrestore(&dd->zone_lock, flags);
421 :
422 : return rq;
423 : }
424 :
425 : /*
426 : * Returns true if and only if @rq started after @latest_start where
427 : * @latest_start is in jiffies.
428 : */
429 : static bool started_after(struct deadline_data *dd, struct request *rq,
430 : unsigned long latest_start)
431 : {
432 0 : unsigned long start_time = (unsigned long)rq->fifo_time;
433 :
434 0 : start_time -= dd->fifo_expire[rq_data_dir(rq)];
435 :
436 0 : return time_after(start_time, latest_start);
437 : }
438 :
439 : /*
440 : * deadline_dispatch_requests selects the best request according to
441 : * read/write expire, fifo_batch, etc and with a start time <= @latest_start.
442 : */
443 0 : static struct request *__dd_dispatch_request(struct deadline_data *dd,
444 : struct dd_per_prio *per_prio,
445 : unsigned long latest_start)
446 : {
447 : struct request *rq, *next_rq;
448 : enum dd_data_dir data_dir;
449 : enum dd_prio prio;
450 : u8 ioprio_class;
451 :
452 : lockdep_assert_held(&dd->lock);
453 :
454 0 : if (!list_empty(&per_prio->dispatch)) {
455 0 : rq = list_first_entry(&per_prio->dispatch, struct request,
456 : queuelist);
457 0 : if (started_after(dd, rq, latest_start))
458 : return NULL;
459 0 : list_del_init(&rq->queuelist);
460 0 : data_dir = rq_data_dir(rq);
461 0 : goto done;
462 : }
463 :
464 : /*
465 : * batches are currently reads XOR writes
466 : */
467 0 : rq = deadline_next_request(dd, per_prio, dd->last_dir);
468 0 : if (rq && dd->batching < dd->fifo_batch) {
469 : /* we have a next request and are still entitled to batch */
470 0 : data_dir = rq_data_dir(rq);
471 0 : goto dispatch_request;
472 : }
473 :
474 : /*
475 : * at this point we are not running a batch. select the appropriate
476 : * data direction (read / write)
477 : */
478 :
479 0 : if (!list_empty(&per_prio->fifo_list[DD_READ])) {
480 0 : BUG_ON(RB_EMPTY_ROOT(&per_prio->sort_list[DD_READ]));
481 :
482 0 : if (deadline_fifo_request(dd, per_prio, DD_WRITE) &&
483 0 : (dd->starved++ >= dd->writes_starved))
484 : goto dispatch_writes;
485 :
486 : data_dir = DD_READ;
487 :
488 : goto dispatch_find_request;
489 : }
490 :
491 : /*
492 : * there are either no reads or writes have been starved
493 : */
494 :
495 0 : if (!list_empty(&per_prio->fifo_list[DD_WRITE])) {
496 : dispatch_writes:
497 0 : BUG_ON(RB_EMPTY_ROOT(&per_prio->sort_list[DD_WRITE]));
498 :
499 0 : dd->starved = 0;
500 :
501 0 : data_dir = DD_WRITE;
502 :
503 0 : goto dispatch_find_request;
504 : }
505 :
506 : return NULL;
507 :
508 : dispatch_find_request:
509 : /*
510 : * we are not running a batch, find best request for selected data_dir
511 : */
512 0 : next_rq = deadline_next_request(dd, per_prio, data_dir);
513 0 : if (deadline_check_fifo(per_prio, data_dir) || !next_rq) {
514 : /*
515 : * A deadline has expired, the last request was in the other
516 : * direction, or we have run out of higher-sectored requests.
517 : * Start again from the request with the earliest expiry time.
518 : */
519 0 : rq = deadline_fifo_request(dd, per_prio, data_dir);
520 : } else {
521 : /*
522 : * The last req was the same dir and we have a next request in
523 : * sort order. No expired requests so continue on from here.
524 : */
525 : rq = next_rq;
526 : }
527 :
528 : /*
529 : * For a zoned block device, if we only have writes queued and none of
530 : * them can be dispatched, rq will be NULL.
531 : */
532 0 : if (!rq)
533 : return NULL;
534 :
535 0 : dd->last_dir = data_dir;
536 0 : dd->batching = 0;
537 :
538 : dispatch_request:
539 0 : if (started_after(dd, rq, latest_start))
540 : return NULL;
541 :
542 : /*
543 : * rq is the selected appropriate request.
544 : */
545 0 : dd->batching++;
546 0 : deadline_move_request(dd, per_prio, rq);
547 : done:
548 0 : ioprio_class = dd_rq_ioclass(rq);
549 0 : prio = ioprio_class_to_prio[ioprio_class];
550 0 : dd->per_prio[prio].latest_pos[data_dir] = blk_rq_pos(rq);
551 0 : dd->per_prio[prio].stats.dispatched++;
552 : /*
553 : * If the request needs its target zone locked, do it.
554 : */
555 0 : blk_req_zone_write_lock(rq);
556 0 : rq->rq_flags |= RQF_STARTED;
557 0 : return rq;
558 : }
559 :
560 : /*
561 : * Check whether there are any requests with priority other than DD_RT_PRIO
562 : * that were inserted more than prio_aging_expire jiffies ago.
563 : */
564 0 : static struct request *dd_dispatch_prio_aged_requests(struct deadline_data *dd,
565 : unsigned long now)
566 : {
567 : struct request *rq;
568 : enum dd_prio prio;
569 : int prio_cnt;
570 :
571 : lockdep_assert_held(&dd->lock);
572 :
573 0 : prio_cnt = !!dd_queued(dd, DD_RT_PRIO) + !!dd_queued(dd, DD_BE_PRIO) +
574 0 : !!dd_queued(dd, DD_IDLE_PRIO);
575 0 : if (prio_cnt < 2)
576 : return NULL;
577 :
578 0 : for (prio = DD_BE_PRIO; prio <= DD_PRIO_MAX; prio++) {
579 0 : rq = __dd_dispatch_request(dd, &dd->per_prio[prio],
580 0 : now - dd->prio_aging_expire);
581 0 : if (rq)
582 : return rq;
583 : }
584 :
585 : return NULL;
586 : }
587 :
588 : /*
589 : * Called from blk_mq_run_hw_queue() -> __blk_mq_sched_dispatch_requests().
590 : *
591 : * One confusing aspect here is that we get called for a specific
592 : * hardware queue, but we may return a request that is for a
593 : * different hardware queue. This is because mq-deadline has shared
594 : * state for all hardware queues, in terms of sorting, FIFOs, etc.
595 : */
596 0 : static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
597 : {
598 0 : struct deadline_data *dd = hctx->queue->elevator->elevator_data;
599 0 : const unsigned long now = jiffies;
600 : struct request *rq;
601 : enum dd_prio prio;
602 :
603 0 : spin_lock(&dd->lock);
604 0 : rq = dd_dispatch_prio_aged_requests(dd, now);
605 0 : if (rq)
606 : goto unlock;
607 :
608 : /*
609 : * Next, dispatch requests in priority order. Ignore lower priority
610 : * requests if any higher priority requests are pending.
611 : */
612 0 : for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
613 0 : rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now);
614 0 : if (rq || dd_queued(dd, prio))
615 : break;
616 : }
617 :
618 : unlock:
619 0 : spin_unlock(&dd->lock);
620 :
621 0 : return rq;
622 : }
623 :
624 : /*
625 : * Called by __blk_mq_alloc_request(). The shallow_depth value set by this
626 : * function is used by __blk_mq_get_tag().
627 : */
628 0 : static void dd_limit_depth(blk_opf_t opf, struct blk_mq_alloc_data *data)
629 : {
630 0 : struct deadline_data *dd = data->q->elevator->elevator_data;
631 :
632 : /* Do not throttle synchronous reads. */
633 0 : if (op_is_sync(opf) && !op_is_write(opf))
634 : return;
635 :
636 : /*
637 : * Throttle asynchronous requests and writes such that these requests
638 : * do not block the allocation of synchronous requests.
639 : */
640 0 : data->shallow_depth = dd->async_depth;
641 : }
642 :
643 : /* Called by blk_mq_update_nr_requests(). */
644 0 : static void dd_depth_updated(struct blk_mq_hw_ctx *hctx)
645 : {
646 0 : struct request_queue *q = hctx->queue;
647 0 : struct deadline_data *dd = q->elevator->elevator_data;
648 0 : struct blk_mq_tags *tags = hctx->sched_tags;
649 :
650 0 : dd->async_depth = max(1UL, 3 * q->nr_requests / 4);
651 :
652 0 : sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, dd->async_depth);
653 0 : }
654 :
655 : /* Called by blk_mq_init_hctx() and blk_mq_init_sched(). */
656 0 : static int dd_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
657 : {
658 0 : dd_depth_updated(hctx);
659 0 : return 0;
660 : }
661 :
662 0 : static void dd_exit_sched(struct elevator_queue *e)
663 : {
664 0 : struct deadline_data *dd = e->elevator_data;
665 : enum dd_prio prio;
666 :
667 0 : for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
668 0 : struct dd_per_prio *per_prio = &dd->per_prio[prio];
669 0 : const struct io_stats_per_prio *stats = &per_prio->stats;
670 : uint32_t queued;
671 :
672 0 : WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_READ]));
673 0 : WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_WRITE]));
674 :
675 0 : spin_lock(&dd->lock);
676 0 : queued = dd_queued(dd, prio);
677 0 : spin_unlock(&dd->lock);
678 :
679 0 : WARN_ONCE(queued != 0,
680 : "statistics for priority %d: i %u m %u d %u c %u\n",
681 : prio, stats->inserted, stats->merged,
682 : stats->dispatched, atomic_read(&stats->completed));
683 : }
684 :
685 0 : kfree(dd);
686 0 : }
687 :
688 : /*
689 : * initialize elevator private data (deadline_data).
690 : */
691 0 : static int dd_init_sched(struct request_queue *q, struct elevator_type *e)
692 : {
693 : struct deadline_data *dd;
694 : struct elevator_queue *eq;
695 : enum dd_prio prio;
696 0 : int ret = -ENOMEM;
697 :
698 0 : eq = elevator_alloc(q, e);
699 0 : if (!eq)
700 : return ret;
701 :
702 0 : dd = kzalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
703 0 : if (!dd)
704 : goto put_eq;
705 :
706 0 : eq->elevator_data = dd;
707 :
708 0 : for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
709 0 : struct dd_per_prio *per_prio = &dd->per_prio[prio];
710 :
711 0 : INIT_LIST_HEAD(&per_prio->dispatch);
712 0 : INIT_LIST_HEAD(&per_prio->fifo_list[DD_READ]);
713 0 : INIT_LIST_HEAD(&per_prio->fifo_list[DD_WRITE]);
714 0 : per_prio->sort_list[DD_READ] = RB_ROOT;
715 0 : per_prio->sort_list[DD_WRITE] = RB_ROOT;
716 : }
717 0 : dd->fifo_expire[DD_READ] = read_expire;
718 0 : dd->fifo_expire[DD_WRITE] = write_expire;
719 0 : dd->writes_starved = writes_starved;
720 0 : dd->front_merges = 1;
721 0 : dd->last_dir = DD_WRITE;
722 0 : dd->fifo_batch = fifo_batch;
723 0 : dd->prio_aging_expire = prio_aging_expire;
724 0 : spin_lock_init(&dd->lock);
725 0 : spin_lock_init(&dd->zone_lock);
726 :
727 : /* We dispatch from request queue wide instead of hw queue */
728 0 : blk_queue_flag_set(QUEUE_FLAG_SQ_SCHED, q);
729 :
730 0 : q->elevator = eq;
731 0 : return 0;
732 :
733 : put_eq:
734 0 : kobject_put(&eq->kobj);
735 0 : return ret;
736 : }
737 :
738 : /*
739 : * Try to merge @bio into an existing request. If @bio has been merged into
740 : * an existing request, store the pointer to that request into *@rq.
741 : */
742 0 : static int dd_request_merge(struct request_queue *q, struct request **rq,
743 : struct bio *bio)
744 : {
745 0 : struct deadline_data *dd = q->elevator->elevator_data;
746 0 : const u8 ioprio_class = IOPRIO_PRIO_CLASS(bio->bi_ioprio);
747 0 : const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
748 0 : struct dd_per_prio *per_prio = &dd->per_prio[prio];
749 0 : sector_t sector = bio_end_sector(bio);
750 : struct request *__rq;
751 :
752 0 : if (!dd->front_merges)
753 : return ELEVATOR_NO_MERGE;
754 :
755 0 : __rq = elv_rb_find(&per_prio->sort_list[bio_data_dir(bio)], sector);
756 0 : if (__rq) {
757 0 : BUG_ON(sector != blk_rq_pos(__rq));
758 :
759 0 : if (elv_bio_merge_ok(__rq, bio)) {
760 0 : *rq = __rq;
761 0 : if (blk_discard_mergable(__rq))
762 : return ELEVATOR_DISCARD_MERGE;
763 0 : return ELEVATOR_FRONT_MERGE;
764 : }
765 : }
766 :
767 : return ELEVATOR_NO_MERGE;
768 : }
769 :
770 : /*
771 : * Attempt to merge a bio into an existing request. This function is called
772 : * before @bio is associated with a request.
773 : */
774 0 : static bool dd_bio_merge(struct request_queue *q, struct bio *bio,
775 : unsigned int nr_segs)
776 : {
777 0 : struct deadline_data *dd = q->elevator->elevator_data;
778 0 : struct request *free = NULL;
779 : bool ret;
780 :
781 0 : spin_lock(&dd->lock);
782 0 : ret = blk_mq_sched_try_merge(q, bio, nr_segs, &free);
783 0 : spin_unlock(&dd->lock);
784 :
785 0 : if (free)
786 0 : blk_mq_free_request(free);
787 :
788 0 : return ret;
789 : }
790 :
791 : /*
792 : * add rq to rbtree and fifo
793 : */
794 0 : static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
795 : blk_insert_t flags, struct list_head *free)
796 : {
797 0 : struct request_queue *q = hctx->queue;
798 0 : struct deadline_data *dd = q->elevator->elevator_data;
799 0 : const enum dd_data_dir data_dir = rq_data_dir(rq);
800 0 : u16 ioprio = req_get_ioprio(rq);
801 0 : u8 ioprio_class = IOPRIO_PRIO_CLASS(ioprio);
802 : struct dd_per_prio *per_prio;
803 : enum dd_prio prio;
804 :
805 : lockdep_assert_held(&dd->lock);
806 :
807 : /*
808 : * This may be a requeue of a write request that has locked its
809 : * target zone. If it is the case, this releases the zone lock.
810 : */
811 0 : blk_req_zone_write_unlock(rq);
812 :
813 0 : prio = ioprio_class_to_prio[ioprio_class];
814 0 : per_prio = &dd->per_prio[prio];
815 0 : if (!rq->elv.priv[0]) {
816 0 : per_prio->stats.inserted++;
817 0 : rq->elv.priv[0] = (void *)(uintptr_t)1;
818 : }
819 :
820 0 : if (blk_mq_sched_try_insert_merge(q, rq, free))
821 : return;
822 :
823 0 : trace_block_rq_insert(rq);
824 :
825 0 : if (flags & BLK_MQ_INSERT_AT_HEAD) {
826 0 : list_add(&rq->queuelist, &per_prio->dispatch);
827 0 : rq->fifo_time = jiffies;
828 : } else {
829 : struct list_head *insert_before;
830 :
831 0 : deadline_add_rq_rb(per_prio, rq);
832 :
833 0 : if (rq_mergeable(rq)) {
834 0 : elv_rqhash_add(q, rq);
835 0 : if (!q->last_merge)
836 0 : q->last_merge = rq;
837 : }
838 :
839 : /*
840 : * set expire time and add to fifo list
841 : */
842 0 : rq->fifo_time = jiffies + dd->fifo_expire[data_dir];
843 0 : insert_before = &per_prio->fifo_list[data_dir];
844 : #ifdef CONFIG_BLK_DEV_ZONED
845 : /*
846 : * Insert zoned writes such that requests are sorted by
847 : * position per zone.
848 : */
849 : if (blk_rq_is_seq_zoned_write(rq)) {
850 : struct request *rq2 = deadline_latter_request(rq);
851 :
852 : if (rq2 && blk_rq_zone_no(rq2) == blk_rq_zone_no(rq))
853 : insert_before = &rq2->queuelist;
854 : }
855 : #endif
856 0 : list_add_tail(&rq->queuelist, insert_before);
857 : }
858 : }
859 :
860 : /*
861 : * Called from blk_mq_insert_request() or blk_mq_dispatch_plug_list().
862 : */
863 0 : static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
864 : struct list_head *list,
865 : blk_insert_t flags)
866 : {
867 0 : struct request_queue *q = hctx->queue;
868 0 : struct deadline_data *dd = q->elevator->elevator_data;
869 0 : LIST_HEAD(free);
870 :
871 0 : spin_lock(&dd->lock);
872 0 : while (!list_empty(list)) {
873 : struct request *rq;
874 :
875 0 : rq = list_first_entry(list, struct request, queuelist);
876 0 : list_del_init(&rq->queuelist);
877 0 : dd_insert_request(hctx, rq, flags, &free);
878 : }
879 0 : spin_unlock(&dd->lock);
880 :
881 0 : blk_mq_free_requests(&free);
882 0 : }
883 :
884 : /* Callback from inside blk_mq_rq_ctx_init(). */
885 0 : static void dd_prepare_request(struct request *rq)
886 : {
887 0 : rq->elv.priv[0] = NULL;
888 0 : }
889 :
890 : static bool dd_has_write_work(struct blk_mq_hw_ctx *hctx)
891 : {
892 : struct deadline_data *dd = hctx->queue->elevator->elevator_data;
893 : enum dd_prio p;
894 :
895 : for (p = 0; p <= DD_PRIO_MAX; p++)
896 : if (!list_empty_careful(&dd->per_prio[p].fifo_list[DD_WRITE]))
897 : return true;
898 :
899 : return false;
900 : }
901 :
902 : /*
903 : * Callback from inside blk_mq_free_request().
904 : *
905 : * For zoned block devices, write unlock the target zone of
906 : * completed write requests. Do this while holding the zone lock
907 : * spinlock so that the zone is never unlocked while deadline_fifo_request()
908 : * or deadline_next_request() are executing. This function is called for
909 : * all requests, whether or not these requests complete successfully.
910 : *
911 : * For a zoned block device, __dd_dispatch_request() may have stopped
912 : * dispatching requests if all the queued requests are write requests directed
913 : * at zones that are already locked due to on-going write requests. To ensure
914 : * write request dispatch progress in this case, mark the queue as needing a
915 : * restart to ensure that the queue is run again after completion of the
916 : * request and zones being unlocked.
917 : */
918 0 : static void dd_finish_request(struct request *rq)
919 : {
920 0 : struct request_queue *q = rq->q;
921 0 : struct deadline_data *dd = q->elevator->elevator_data;
922 0 : const u8 ioprio_class = dd_rq_ioclass(rq);
923 0 : const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
924 0 : struct dd_per_prio *per_prio = &dd->per_prio[prio];
925 :
926 : /*
927 : * The block layer core may call dd_finish_request() without having
928 : * called dd_insert_requests(). Skip requests that bypassed I/O
929 : * scheduling. See also blk_mq_request_bypass_insert().
930 : */
931 0 : if (!rq->elv.priv[0])
932 : return;
933 :
934 0 : atomic_inc(&per_prio->stats.completed);
935 :
936 0 : if (blk_queue_is_zoned(q)) {
937 : unsigned long flags;
938 :
939 : spin_lock_irqsave(&dd->zone_lock, flags);
940 : blk_req_zone_write_unlock(rq);
941 : spin_unlock_irqrestore(&dd->zone_lock, flags);
942 :
943 : if (dd_has_write_work(rq->mq_hctx))
944 : blk_mq_sched_mark_restart_hctx(rq->mq_hctx);
945 : }
946 : }
947 :
948 0 : static bool dd_has_work_for_prio(struct dd_per_prio *per_prio)
949 : {
950 0 : return !list_empty_careful(&per_prio->dispatch) ||
951 0 : !list_empty_careful(&per_prio->fifo_list[DD_READ]) ||
952 0 : !list_empty_careful(&per_prio->fifo_list[DD_WRITE]);
953 : }
954 :
955 0 : static bool dd_has_work(struct blk_mq_hw_ctx *hctx)
956 : {
957 0 : struct deadline_data *dd = hctx->queue->elevator->elevator_data;
958 : enum dd_prio prio;
959 :
960 0 : for (prio = 0; prio <= DD_PRIO_MAX; prio++)
961 0 : if (dd_has_work_for_prio(&dd->per_prio[prio]))
962 : return true;
963 :
964 : return false;
965 : }
966 :
967 : /*
968 : * sysfs parts below
969 : */
970 : #define SHOW_INT(__FUNC, __VAR) \
971 : static ssize_t __FUNC(struct elevator_queue *e, char *page) \
972 : { \
973 : struct deadline_data *dd = e->elevator_data; \
974 : \
975 : return sysfs_emit(page, "%d\n", __VAR); \
976 : }
977 : #define SHOW_JIFFIES(__FUNC, __VAR) SHOW_INT(__FUNC, jiffies_to_msecs(__VAR))
978 0 : SHOW_JIFFIES(deadline_read_expire_show, dd->fifo_expire[DD_READ]);
979 0 : SHOW_JIFFIES(deadline_write_expire_show, dd->fifo_expire[DD_WRITE]);
980 0 : SHOW_JIFFIES(deadline_prio_aging_expire_show, dd->prio_aging_expire);
981 0 : SHOW_INT(deadline_writes_starved_show, dd->writes_starved);
982 0 : SHOW_INT(deadline_front_merges_show, dd->front_merges);
983 0 : SHOW_INT(deadline_async_depth_show, dd->async_depth);
984 0 : SHOW_INT(deadline_fifo_batch_show, dd->fifo_batch);
985 : #undef SHOW_INT
986 : #undef SHOW_JIFFIES
987 :
988 : #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
989 : static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
990 : { \
991 : struct deadline_data *dd = e->elevator_data; \
992 : int __data, __ret; \
993 : \
994 : __ret = kstrtoint(page, 0, &__data); \
995 : if (__ret < 0) \
996 : return __ret; \
997 : if (__data < (MIN)) \
998 : __data = (MIN); \
999 : else if (__data > (MAX)) \
1000 : __data = (MAX); \
1001 : *(__PTR) = __CONV(__data); \
1002 : return count; \
1003 : }
1004 : #define STORE_INT(__FUNC, __PTR, MIN, MAX) \
1005 : STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, )
1006 : #define STORE_JIFFIES(__FUNC, __PTR, MIN, MAX) \
1007 : STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, msecs_to_jiffies)
1008 0 : STORE_JIFFIES(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX);
1009 0 : STORE_JIFFIES(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX);
1010 0 : STORE_JIFFIES(deadline_prio_aging_expire_store, &dd->prio_aging_expire, 0, INT_MAX);
1011 0 : STORE_INT(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX);
1012 0 : STORE_INT(deadline_front_merges_store, &dd->front_merges, 0, 1);
1013 0 : STORE_INT(deadline_async_depth_store, &dd->async_depth, 1, INT_MAX);
1014 0 : STORE_INT(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX);
1015 : #undef STORE_FUNCTION
1016 : #undef STORE_INT
1017 : #undef STORE_JIFFIES
1018 :
1019 : #define DD_ATTR(name) \
1020 : __ATTR(name, 0644, deadline_##name##_show, deadline_##name##_store)
1021 :
1022 : static struct elv_fs_entry deadline_attrs[] = {
1023 : DD_ATTR(read_expire),
1024 : DD_ATTR(write_expire),
1025 : DD_ATTR(writes_starved),
1026 : DD_ATTR(front_merges),
1027 : DD_ATTR(async_depth),
1028 : DD_ATTR(fifo_batch),
1029 : DD_ATTR(prio_aging_expire),
1030 : __ATTR_NULL
1031 : };
1032 :
1033 : #ifdef CONFIG_BLK_DEBUG_FS
1034 : #define DEADLINE_DEBUGFS_DDIR_ATTRS(prio, data_dir, name) \
1035 : static void *deadline_##name##_fifo_start(struct seq_file *m, \
1036 : loff_t *pos) \
1037 : __acquires(&dd->lock) \
1038 : { \
1039 : struct request_queue *q = m->private; \
1040 : struct deadline_data *dd = q->elevator->elevator_data; \
1041 : struct dd_per_prio *per_prio = &dd->per_prio[prio]; \
1042 : \
1043 : spin_lock(&dd->lock); \
1044 : return seq_list_start(&per_prio->fifo_list[data_dir], *pos); \
1045 : } \
1046 : \
1047 : static void *deadline_##name##_fifo_next(struct seq_file *m, void *v, \
1048 : loff_t *pos) \
1049 : { \
1050 : struct request_queue *q = m->private; \
1051 : struct deadline_data *dd = q->elevator->elevator_data; \
1052 : struct dd_per_prio *per_prio = &dd->per_prio[prio]; \
1053 : \
1054 : return seq_list_next(v, &per_prio->fifo_list[data_dir], pos); \
1055 : } \
1056 : \
1057 : static void deadline_##name##_fifo_stop(struct seq_file *m, void *v) \
1058 : __releases(&dd->lock) \
1059 : { \
1060 : struct request_queue *q = m->private; \
1061 : struct deadline_data *dd = q->elevator->elevator_data; \
1062 : \
1063 : spin_unlock(&dd->lock); \
1064 : } \
1065 : \
1066 : static const struct seq_operations deadline_##name##_fifo_seq_ops = { \
1067 : .start = deadline_##name##_fifo_start, \
1068 : .next = deadline_##name##_fifo_next, \
1069 : .stop = deadline_##name##_fifo_stop, \
1070 : .show = blk_mq_debugfs_rq_show, \
1071 : }; \
1072 : \
1073 : static int deadline_##name##_next_rq_show(void *data, \
1074 : struct seq_file *m) \
1075 : { \
1076 : struct request_queue *q = data; \
1077 : struct deadline_data *dd = q->elevator->elevator_data; \
1078 : struct dd_per_prio *per_prio = &dd->per_prio[prio]; \
1079 : struct request *rq; \
1080 : \
1081 : rq = deadline_from_pos(per_prio, data_dir, \
1082 : per_prio->latest_pos[data_dir]); \
1083 : if (rq) \
1084 : __blk_mq_debugfs_rq_show(m, rq); \
1085 : return 0; \
1086 : }
1087 :
1088 : DEADLINE_DEBUGFS_DDIR_ATTRS(DD_RT_PRIO, DD_READ, read0);
1089 : DEADLINE_DEBUGFS_DDIR_ATTRS(DD_RT_PRIO, DD_WRITE, write0);
1090 : DEADLINE_DEBUGFS_DDIR_ATTRS(DD_BE_PRIO, DD_READ, read1);
1091 : DEADLINE_DEBUGFS_DDIR_ATTRS(DD_BE_PRIO, DD_WRITE, write1);
1092 : DEADLINE_DEBUGFS_DDIR_ATTRS(DD_IDLE_PRIO, DD_READ, read2);
1093 : DEADLINE_DEBUGFS_DDIR_ATTRS(DD_IDLE_PRIO, DD_WRITE, write2);
1094 : #undef DEADLINE_DEBUGFS_DDIR_ATTRS
1095 :
1096 : static int deadline_batching_show(void *data, struct seq_file *m)
1097 : {
1098 : struct request_queue *q = data;
1099 : struct deadline_data *dd = q->elevator->elevator_data;
1100 :
1101 : seq_printf(m, "%u\n", dd->batching);
1102 : return 0;
1103 : }
1104 :
1105 : static int deadline_starved_show(void *data, struct seq_file *m)
1106 : {
1107 : struct request_queue *q = data;
1108 : struct deadline_data *dd = q->elevator->elevator_data;
1109 :
1110 : seq_printf(m, "%u\n", dd->starved);
1111 : return 0;
1112 : }
1113 :
1114 : static int dd_async_depth_show(void *data, struct seq_file *m)
1115 : {
1116 : struct request_queue *q = data;
1117 : struct deadline_data *dd = q->elevator->elevator_data;
1118 :
1119 : seq_printf(m, "%u\n", dd->async_depth);
1120 : return 0;
1121 : }
1122 :
1123 : static int dd_queued_show(void *data, struct seq_file *m)
1124 : {
1125 : struct request_queue *q = data;
1126 : struct deadline_data *dd = q->elevator->elevator_data;
1127 : u32 rt, be, idle;
1128 :
1129 : spin_lock(&dd->lock);
1130 : rt = dd_queued(dd, DD_RT_PRIO);
1131 : be = dd_queued(dd, DD_BE_PRIO);
1132 : idle = dd_queued(dd, DD_IDLE_PRIO);
1133 : spin_unlock(&dd->lock);
1134 :
1135 : seq_printf(m, "%u %u %u\n", rt, be, idle);
1136 :
1137 : return 0;
1138 : }
1139 :
1140 : /* Number of requests owned by the block driver for a given priority. */
1141 : static u32 dd_owned_by_driver(struct deadline_data *dd, enum dd_prio prio)
1142 : {
1143 : const struct io_stats_per_prio *stats = &dd->per_prio[prio].stats;
1144 :
1145 : lockdep_assert_held(&dd->lock);
1146 :
1147 : return stats->dispatched + stats->merged -
1148 : atomic_read(&stats->completed);
1149 : }
1150 :
1151 : static int dd_owned_by_driver_show(void *data, struct seq_file *m)
1152 : {
1153 : struct request_queue *q = data;
1154 : struct deadline_data *dd = q->elevator->elevator_data;
1155 : u32 rt, be, idle;
1156 :
1157 : spin_lock(&dd->lock);
1158 : rt = dd_owned_by_driver(dd, DD_RT_PRIO);
1159 : be = dd_owned_by_driver(dd, DD_BE_PRIO);
1160 : idle = dd_owned_by_driver(dd, DD_IDLE_PRIO);
1161 : spin_unlock(&dd->lock);
1162 :
1163 : seq_printf(m, "%u %u %u\n", rt, be, idle);
1164 :
1165 : return 0;
1166 : }
1167 :
1168 : #define DEADLINE_DISPATCH_ATTR(prio) \
1169 : static void *deadline_dispatch##prio##_start(struct seq_file *m, \
1170 : loff_t *pos) \
1171 : __acquires(&dd->lock) \
1172 : { \
1173 : struct request_queue *q = m->private; \
1174 : struct deadline_data *dd = q->elevator->elevator_data; \
1175 : struct dd_per_prio *per_prio = &dd->per_prio[prio]; \
1176 : \
1177 : spin_lock(&dd->lock); \
1178 : return seq_list_start(&per_prio->dispatch, *pos); \
1179 : } \
1180 : \
1181 : static void *deadline_dispatch##prio##_next(struct seq_file *m, \
1182 : void *v, loff_t *pos) \
1183 : { \
1184 : struct request_queue *q = m->private; \
1185 : struct deadline_data *dd = q->elevator->elevator_data; \
1186 : struct dd_per_prio *per_prio = &dd->per_prio[prio]; \
1187 : \
1188 : return seq_list_next(v, &per_prio->dispatch, pos); \
1189 : } \
1190 : \
1191 : static void deadline_dispatch##prio##_stop(struct seq_file *m, void *v) \
1192 : __releases(&dd->lock) \
1193 : { \
1194 : struct request_queue *q = m->private; \
1195 : struct deadline_data *dd = q->elevator->elevator_data; \
1196 : \
1197 : spin_unlock(&dd->lock); \
1198 : } \
1199 : \
1200 : static const struct seq_operations deadline_dispatch##prio##_seq_ops = { \
1201 : .start = deadline_dispatch##prio##_start, \
1202 : .next = deadline_dispatch##prio##_next, \
1203 : .stop = deadline_dispatch##prio##_stop, \
1204 : .show = blk_mq_debugfs_rq_show, \
1205 : }
1206 :
1207 : DEADLINE_DISPATCH_ATTR(0);
1208 : DEADLINE_DISPATCH_ATTR(1);
1209 : DEADLINE_DISPATCH_ATTR(2);
1210 : #undef DEADLINE_DISPATCH_ATTR
1211 :
1212 : #define DEADLINE_QUEUE_DDIR_ATTRS(name) \
1213 : {#name "_fifo_list", 0400, \
1214 : .seq_ops = &deadline_##name##_fifo_seq_ops}
1215 : #define DEADLINE_NEXT_RQ_ATTR(name) \
1216 : {#name "_next_rq", 0400, deadline_##name##_next_rq_show}
1217 : static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = {
1218 : DEADLINE_QUEUE_DDIR_ATTRS(read0),
1219 : DEADLINE_QUEUE_DDIR_ATTRS(write0),
1220 : DEADLINE_QUEUE_DDIR_ATTRS(read1),
1221 : DEADLINE_QUEUE_DDIR_ATTRS(write1),
1222 : DEADLINE_QUEUE_DDIR_ATTRS(read2),
1223 : DEADLINE_QUEUE_DDIR_ATTRS(write2),
1224 : DEADLINE_NEXT_RQ_ATTR(read0),
1225 : DEADLINE_NEXT_RQ_ATTR(write0),
1226 : DEADLINE_NEXT_RQ_ATTR(read1),
1227 : DEADLINE_NEXT_RQ_ATTR(write1),
1228 : DEADLINE_NEXT_RQ_ATTR(read2),
1229 : DEADLINE_NEXT_RQ_ATTR(write2),
1230 : {"batching", 0400, deadline_batching_show},
1231 : {"starved", 0400, deadline_starved_show},
1232 : {"async_depth", 0400, dd_async_depth_show},
1233 : {"dispatch0", 0400, .seq_ops = &deadline_dispatch0_seq_ops},
1234 : {"dispatch1", 0400, .seq_ops = &deadline_dispatch1_seq_ops},
1235 : {"dispatch2", 0400, .seq_ops = &deadline_dispatch2_seq_ops},
1236 : {"owned_by_driver", 0400, dd_owned_by_driver_show},
1237 : {"queued", 0400, dd_queued_show},
1238 : {},
1239 : };
1240 : #undef DEADLINE_QUEUE_DDIR_ATTRS
1241 : #endif
1242 :
1243 : static struct elevator_type mq_deadline = {
1244 : .ops = {
1245 : .depth_updated = dd_depth_updated,
1246 : .limit_depth = dd_limit_depth,
1247 : .insert_requests = dd_insert_requests,
1248 : .dispatch_request = dd_dispatch_request,
1249 : .prepare_request = dd_prepare_request,
1250 : .finish_request = dd_finish_request,
1251 : .next_request = elv_rb_latter_request,
1252 : .former_request = elv_rb_former_request,
1253 : .bio_merge = dd_bio_merge,
1254 : .request_merge = dd_request_merge,
1255 : .requests_merged = dd_merged_requests,
1256 : .request_merged = dd_request_merged,
1257 : .has_work = dd_has_work,
1258 : .init_sched = dd_init_sched,
1259 : .exit_sched = dd_exit_sched,
1260 : .init_hctx = dd_init_hctx,
1261 : },
1262 :
1263 : #ifdef CONFIG_BLK_DEBUG_FS
1264 : .queue_debugfs_attrs = deadline_queue_debugfs_attrs,
1265 : #endif
1266 : .elevator_attrs = deadline_attrs,
1267 : .elevator_name = "mq-deadline",
1268 : .elevator_alias = "deadline",
1269 : .elevator_features = ELEVATOR_F_ZBD_SEQ_WRITE,
1270 : .elevator_owner = THIS_MODULE,
1271 : };
1272 : MODULE_ALIAS("mq-deadline-iosched");
1273 :
1274 1 : static int __init deadline_init(void)
1275 : {
1276 1 : return elv_register(&mq_deadline);
1277 : }
1278 :
1279 0 : static void __exit deadline_exit(void)
1280 : {
1281 0 : elv_unregister(&mq_deadline);
1282 0 : }
1283 :
1284 : module_init(deadline_init);
1285 : module_exit(deadline_exit);
1286 :
1287 : MODULE_AUTHOR("Jens Axboe, Damien Le Moal and Bart Van Assche");
1288 : MODULE_LICENSE("GPL");
1289 : MODULE_DESCRIPTION("MQ deadline IO scheduler");
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