Commit | Line | Data |
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3dcf60bc | 1 | // SPDX-License-Identifier: GPL-2.0 |
945ffb60 JA |
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> | |
945ffb60 JA |
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 | ||
b357e4a6 CK |
19 | #include <trace/events/block.h> |
20 | ||
2e9bc346 | 21 | #include "elevator.h" |
945ffb60 JA |
22 | #include "blk.h" |
23 | #include "blk-mq.h" | |
daaadb3e | 24 | #include "blk-mq-debugfs.h" |
945ffb60 JA |
25 | #include "blk-mq-sched.h" |
26 | ||
27 | /* | |
898bd37a | 28 | * See Documentation/block/deadline-iosched.rst |
945ffb60 JA |
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! */ | |
322cff70 BVA |
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; | |
945ffb60 JA |
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 | ||
004a26b3 BVA |
41 | enum dd_data_dir { |
42 | DD_READ = READ, | |
43 | DD_WRITE = WRITE, | |
44 | }; | |
45 | ||
46 | enum { DD_DIR_COUNT = 2 }; | |
47 | ||
c807ab52 BVA |
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 | ||
bce0363e BVA |
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 | */ | |
0f783995 | 62 | struct io_stats_per_prio { |
bce0363e BVA |
63 | uint32_t inserted; |
64 | uint32_t merged; | |
65 | uint32_t dispatched; | |
66 | atomic_t completed; | |
38ba64d1 BVA |
67 | }; |
68 | ||
c807ab52 BVA |
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]; | |
83c46ed6 BVA |
77 | /* Position of the most recently dispatched request. */ |
78 | sector_t latest_pos[DD_DIR_COUNT]; | |
bce0363e | 79 | struct io_stats_per_prio stats; |
c807ab52 BVA |
80 | }; |
81 | ||
945ffb60 JA |
82 | struct deadline_data { |
83 | /* | |
84 | * run time data | |
85 | */ | |
86 | ||
c807ab52 | 87 | struct dd_per_prio per_prio[DD_PRIO_COUNT]; |
945ffb60 | 88 | |
d672d325 BVA |
89 | /* Data direction of latest dispatched request. */ |
90 | enum dd_data_dir last_dir; | |
945ffb60 JA |
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 | */ | |
004a26b3 | 97 | int fifo_expire[DD_DIR_COUNT]; |
945ffb60 JA |
98 | int fifo_batch; |
99 | int writes_starved; | |
100 | int front_merges; | |
07757588 | 101 | u32 async_depth; |
322cff70 | 102 | int prio_aging_expire; |
945ffb60 JA |
103 | |
104 | spinlock_t lock; | |
5700f691 | 105 | spinlock_t zone_lock; |
c807ab52 BVA |
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, | |
945ffb60 JA |
114 | }; |
115 | ||
116 | static inline struct rb_root * | |
c807ab52 | 117 | deadline_rb_root(struct dd_per_prio *per_prio, struct request *rq) |
945ffb60 | 118 | { |
c807ab52 BVA |
119 | 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 | return IOPRIO_PRIO_CLASS(req_get_ioprio(rq)); | |
945ffb60 JA |
129 | } |
130 | ||
015d02f4 DLM |
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 | ||
945ffb60 JA |
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 | ||
0effb390 BVA |
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 | */ | |
83c46ed6 BVA |
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 | struct rb_node *node = per_prio->sort_list[data_dir].rb_node; | |
167 | struct request *rq, *res = NULL; | |
168 | ||
0effb390 BVA |
169 | 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 | ||
83c46ed6 BVA |
181 | while (node) { |
182 | rq = rb_entry_rq(node); | |
183 | if (blk_rq_pos(rq) >= pos) { | |
184 | res = rq; | |
185 | node = node->rb_left; | |
186 | } else { | |
187 | node = node->rb_right; | |
188 | } | |
189 | } | |
190 | return res; | |
191 | } | |
192 | ||
945ffb60 | 193 | static void |
c807ab52 | 194 | deadline_add_rq_rb(struct dd_per_prio *per_prio, struct request *rq) |
945ffb60 | 195 | { |
c807ab52 | 196 | struct rb_root *root = deadline_rb_root(per_prio, rq); |
945ffb60 JA |
197 | |
198 | elv_rb_add(root, rq); | |
199 | } | |
200 | ||
201 | static inline void | |
c807ab52 | 202 | deadline_del_rq_rb(struct dd_per_prio *per_prio, struct request *rq) |
945ffb60 | 203 | { |
c807ab52 | 204 | elv_rb_del(deadline_rb_root(per_prio, rq), rq); |
945ffb60 JA |
205 | } |
206 | ||
207 | /* | |
208 | * remove rq from rbtree and fifo. | |
209 | */ | |
c807ab52 BVA |
210 | static void deadline_remove_request(struct request_queue *q, |
211 | struct dd_per_prio *per_prio, | |
212 | struct request *rq) | |
945ffb60 | 213 | { |
945ffb60 JA |
214 | list_del_init(&rq->queuelist); |
215 | ||
216 | /* | |
217 | * We might not be on the rbtree, if we are doing an insert merge | |
218 | */ | |
219 | if (!RB_EMPTY_NODE(&rq->rb_node)) | |
c807ab52 | 220 | deadline_del_rq_rb(per_prio, rq); |
945ffb60 JA |
221 | |
222 | elv_rqhash_del(q, rq); | |
223 | if (q->last_merge == rq) | |
224 | q->last_merge = NULL; | |
225 | } | |
226 | ||
227 | static void dd_request_merged(struct request_queue *q, struct request *req, | |
34fe7c05 | 228 | enum elv_merge type) |
945ffb60 JA |
229 | { |
230 | struct deadline_data *dd = q->elevator->elevator_data; | |
c807ab52 BVA |
231 | const u8 ioprio_class = dd_rq_ioclass(req); |
232 | const enum dd_prio prio = ioprio_class_to_prio[ioprio_class]; | |
233 | struct dd_per_prio *per_prio = &dd->per_prio[prio]; | |
945ffb60 JA |
234 | |
235 | /* | |
236 | * if the merge was a front merge, we need to reposition request | |
237 | */ | |
238 | if (type == ELEVATOR_FRONT_MERGE) { | |
c807ab52 BVA |
239 | elv_rb_del(deadline_rb_root(per_prio, req), req); |
240 | deadline_add_rq_rb(per_prio, req); | |
945ffb60 JA |
241 | } |
242 | } | |
243 | ||
46eae2e3 BVA |
244 | /* |
245 | * Callback function that is invoked after @next has been merged into @req. | |
246 | */ | |
945ffb60 JA |
247 | static void dd_merged_requests(struct request_queue *q, struct request *req, |
248 | struct request *next) | |
249 | { | |
38ba64d1 | 250 | struct deadline_data *dd = q->elevator->elevator_data; |
c807ab52 BVA |
251 | const u8 ioprio_class = dd_rq_ioclass(next); |
252 | const enum dd_prio prio = ioprio_class_to_prio[ioprio_class]; | |
253 | ||
bce0363e BVA |
254 | lockdep_assert_held(&dd->lock); |
255 | ||
256 | dd->per_prio[prio].stats.merged++; | |
38ba64d1 | 257 | |
945ffb60 JA |
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 | if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) { | |
263 | if (time_before((unsigned long)next->fifo_time, | |
264 | (unsigned long)req->fifo_time)) { | |
265 | list_move(&req->queuelist, &next->queuelist); | |
266 | req->fifo_time = next->fifo_time; | |
267 | } | |
268 | } | |
269 | ||
270 | /* | |
271 | * kill knowledge of next, this one is a goner | |
272 | */ | |
c807ab52 | 273 | deadline_remove_request(q, &dd->per_prio[prio], next); |
945ffb60 JA |
274 | } |
275 | ||
276 | /* | |
277 | * move an entry to dispatch queue | |
278 | */ | |
279 | static void | |
c807ab52 BVA |
280 | deadline_move_request(struct deadline_data *dd, struct dd_per_prio *per_prio, |
281 | struct request *rq) | |
945ffb60 | 282 | { |
945ffb60 JA |
283 | /* |
284 | * take it off the sort and fifo list | |
285 | */ | |
c807ab52 | 286 | deadline_remove_request(rq->q, per_prio, rq); |
945ffb60 JA |
287 | } |
288 | ||
32f64cad BVA |
289 | /* Number of requests queued for a given priority level. */ |
290 | static u32 dd_queued(struct deadline_data *dd, enum dd_prio prio) | |
291 | { | |
bce0363e BVA |
292 | const struct io_stats_per_prio *stats = &dd->per_prio[prio].stats; |
293 | ||
294 | lockdep_assert_held(&dd->lock); | |
295 | ||
296 | return stats->inserted - atomic_read(&stats->completed); | |
32f64cad BVA |
297 | } |
298 | ||
945ffb60 | 299 | /* |
e0d85cde BVA |
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]). | |
945ffb60 | 302 | */ |
e0d85cde BVA |
303 | static inline bool deadline_check_fifo(struct dd_per_prio *per_prio, |
304 | enum dd_data_dir data_dir) | |
945ffb60 | 305 | { |
c807ab52 | 306 | struct request *rq = rq_entry_fifo(per_prio->fifo_list[data_dir].next); |
945ffb60 | 307 | |
e0d85cde | 308 | return time_is_before_eq_jiffies((unsigned long)rq->fifo_time); |
945ffb60 JA |
309 | } |
310 | ||
015d02f4 DLM |
311 | /* |
312 | * Check if rq has a sequential request preceding it. | |
313 | */ | |
3692fec8 | 314 | static bool deadline_is_seq_write(struct deadline_data *dd, struct request *rq) |
015d02f4 DLM |
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); | |
015d02f4 | 332 | |
3b463cbe BVA |
333 | do { |
334 | pos += blk_rq_sectors(rq); | |
015d02f4 | 335 | rq = deadline_latter_request(rq); |
3b463cbe | 336 | } while (rq && blk_rq_pos(rq) == pos); |
015d02f4 DLM |
337 | |
338 | return rq; | |
339 | } | |
340 | ||
bf09ce56 DLM |
341 | /* |
342 | * For the specified data direction, return the next request to | |
343 | * dispatch using arrival ordered lists. | |
344 | */ | |
345 | static struct request * | |
c807ab52 BVA |
346 | deadline_fifo_request(struct deadline_data *dd, struct dd_per_prio *per_prio, |
347 | enum dd_data_dir data_dir) | |
bf09ce56 | 348 | { |
a036e698 | 349 | struct request *rq, *rb_rq, *next; |
5700f691 DLM |
350 | unsigned long flags; |
351 | ||
c807ab52 | 352 | if (list_empty(&per_prio->fifo_list[data_dir])) |
bf09ce56 DLM |
353 | return NULL; |
354 | ||
c807ab52 | 355 | rq = rq_entry_fifo(per_prio->fifo_list[data_dir].next); |
004a26b3 | 356 | if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q)) |
5700f691 DLM |
357 | return rq; |
358 | ||
359 | /* | |
360 | * Look for a write request that can be dispatched, that is one with | |
015d02f4 DLM |
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. | |
5700f691 DLM |
365 | */ |
366 | spin_lock_irqsave(&dd->zone_lock, flags); | |
a036e698 BVA |
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; | |
015d02f4 DLM |
373 | if (blk_req_can_dispatch_to_zone(rq) && |
374 | (blk_queue_nonrot(rq->q) || | |
3692fec8 | 375 | !deadline_is_seq_write(dd, rq))) |
5700f691 DLM |
376 | goto out; |
377 | } | |
378 | rq = NULL; | |
379 | out: | |
380 | spin_unlock_irqrestore(&dd->zone_lock, flags); | |
381 | ||
382 | return rq; | |
bf09ce56 DLM |
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 * | |
c807ab52 BVA |
390 | deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio, |
391 | enum dd_data_dir data_dir) | |
bf09ce56 | 392 | { |
5700f691 DLM |
393 | struct request *rq; |
394 | unsigned long flags; | |
395 | ||
83c46ed6 BVA |
396 | rq = deadline_from_pos(per_prio, data_dir, |
397 | per_prio->latest_pos[data_dir]); | |
5700f691 DLM |
398 | if (!rq) |
399 | return NULL; | |
400 | ||
004a26b3 | 401 | if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q)) |
5700f691 DLM |
402 | return rq; |
403 | ||
404 | /* | |
405 | * Look for a write request that can be dispatched, that is one with | |
015d02f4 DLM |
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. | |
5700f691 DLM |
410 | */ |
411 | spin_lock_irqsave(&dd->zone_lock, flags); | |
412 | while (rq) { | |
413 | if (blk_req_can_dispatch_to_zone(rq)) | |
414 | break; | |
015d02f4 DLM |
415 | if (blk_queue_nonrot(rq->q)) |
416 | rq = deadline_latter_request(rq); | |
417 | else | |
418 | rq = deadline_skip_seq_writes(dd, rq); | |
5700f691 DLM |
419 | } |
420 | spin_unlock_irqrestore(&dd->zone_lock, flags); | |
421 | ||
422 | return rq; | |
bf09ce56 DLM |
423 | } |
424 | ||
322cff70 BVA |
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 | unsigned long start_time = (unsigned long)rq->fifo_time; | |
433 | ||
434 | start_time -= dd->fifo_expire[rq_data_dir(rq)]; | |
435 | ||
436 | return time_after(start_time, latest_start); | |
437 | } | |
438 | ||
945ffb60 JA |
439 | /* |
440 | * deadline_dispatch_requests selects the best request according to | |
322cff70 | 441 | * read/write expire, fifo_batch, etc and with a start time <= @latest_start. |
945ffb60 | 442 | */ |
c807ab52 | 443 | static struct request *__dd_dispatch_request(struct deadline_data *dd, |
322cff70 BVA |
444 | struct dd_per_prio *per_prio, |
445 | unsigned long latest_start) | |
945ffb60 | 446 | { |
bf09ce56 | 447 | struct request *rq, *next_rq; |
004a26b3 | 448 | enum dd_data_dir data_dir; |
38ba64d1 BVA |
449 | enum dd_prio prio; |
450 | u8 ioprio_class; | |
945ffb60 | 451 | |
3bd473f4 BVA |
452 | lockdep_assert_held(&dd->lock); |
453 | ||
c807ab52 BVA |
454 | if (!list_empty(&per_prio->dispatch)) { |
455 | rq = list_first_entry(&per_prio->dispatch, struct request, | |
456 | queuelist); | |
322cff70 BVA |
457 | if (started_after(dd, rq, latest_start)) |
458 | return NULL; | |
945ffb60 | 459 | list_del_init(&rq->queuelist); |
83c46ed6 | 460 | data_dir = rq_data_dir(rq); |
945ffb60 JA |
461 | goto done; |
462 | } | |
463 | ||
945ffb60 JA |
464 | /* |
465 | * batches are currently reads XOR writes | |
466 | */ | |
c807ab52 | 467 | rq = deadline_next_request(dd, per_prio, dd->last_dir); |
83c46ed6 | 468 | if (rq && dd->batching < dd->fifo_batch) { |
45b46b6f | 469 | /* we have a next request and are still entitled to batch */ |
83c46ed6 | 470 | data_dir = rq_data_dir(rq); |
945ffb60 | 471 | goto dispatch_request; |
83c46ed6 | 472 | } |
945ffb60 JA |
473 | |
474 | /* | |
475 | * at this point we are not running a batch. select the appropriate | |
476 | * data direction (read / write) | |
477 | */ | |
478 | ||
c807ab52 BVA |
479 | if (!list_empty(&per_prio->fifo_list[DD_READ])) { |
480 | BUG_ON(RB_EMPTY_ROOT(&per_prio->sort_list[DD_READ])); | |
945ffb60 | 481 | |
c807ab52 | 482 | if (deadline_fifo_request(dd, per_prio, DD_WRITE) && |
5700f691 | 483 | (dd->starved++ >= dd->writes_starved)) |
945ffb60 JA |
484 | goto dispatch_writes; |
485 | ||
004a26b3 | 486 | data_dir = DD_READ; |
945ffb60 JA |
487 | |
488 | goto dispatch_find_request; | |
489 | } | |
490 | ||
491 | /* | |
492 | * there are either no reads or writes have been starved | |
493 | */ | |
494 | ||
c807ab52 | 495 | if (!list_empty(&per_prio->fifo_list[DD_WRITE])) { |
945ffb60 | 496 | dispatch_writes: |
c807ab52 | 497 | BUG_ON(RB_EMPTY_ROOT(&per_prio->sort_list[DD_WRITE])); |
945ffb60 JA |
498 | |
499 | dd->starved = 0; | |
500 | ||
004a26b3 | 501 | data_dir = DD_WRITE; |
945ffb60 JA |
502 | |
503 | 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 | */ | |
c807ab52 BVA |
512 | next_rq = deadline_next_request(dd, per_prio, data_dir); |
513 | if (deadline_check_fifo(per_prio, data_dir) || !next_rq) { | |
945ffb60 JA |
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 | */ | |
c807ab52 | 519 | rq = deadline_fifo_request(dd, per_prio, data_dir); |
945ffb60 JA |
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 | */ | |
bf09ce56 | 525 | rq = next_rq; |
945ffb60 JA |
526 | } |
527 | ||
5700f691 DLM |
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 | if (!rq) | |
533 | return NULL; | |
534 | ||
d672d325 | 535 | dd->last_dir = data_dir; |
945ffb60 JA |
536 | dd->batching = 0; |
537 | ||
538 | dispatch_request: | |
322cff70 BVA |
539 | if (started_after(dd, rq, latest_start)) |
540 | return NULL; | |
541 | ||
945ffb60 JA |
542 | /* |
543 | * rq is the selected appropriate request. | |
544 | */ | |
545 | dd->batching++; | |
c807ab52 | 546 | deadline_move_request(dd, per_prio, rq); |
945ffb60 | 547 | done: |
38ba64d1 BVA |
548 | ioprio_class = dd_rq_ioclass(rq); |
549 | prio = ioprio_class_to_prio[ioprio_class]; | |
83c46ed6 | 550 | dd->per_prio[prio].latest_pos[data_dir] = blk_rq_pos(rq); |
bce0363e | 551 | dd->per_prio[prio].stats.dispatched++; |
5700f691 DLM |
552 | /* |
553 | * If the request needs its target zone locked, do it. | |
554 | */ | |
555 | blk_req_zone_write_lock(rq); | |
945ffb60 JA |
556 | rq->rq_flags |= RQF_STARTED; |
557 | return rq; | |
558 | } | |
559 | ||
322cff70 BVA |
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 | 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 | prio_cnt = !!dd_queued(dd, DD_RT_PRIO) + !!dd_queued(dd, DD_BE_PRIO) + | |
574 | !!dd_queued(dd, DD_IDLE_PRIO); | |
575 | if (prio_cnt < 2) | |
576 | return NULL; | |
577 | ||
578 | for (prio = DD_BE_PRIO; prio <= DD_PRIO_MAX; prio++) { | |
579 | rq = __dd_dispatch_request(dd, &dd->per_prio[prio], | |
580 | now - dd->prio_aging_expire); | |
581 | if (rq) | |
582 | return rq; | |
583 | } | |
584 | ||
585 | return NULL; | |
586 | } | |
587 | ||
ca11f209 | 588 | /* |
46eae2e3 BVA |
589 | * Called from blk_mq_run_hw_queue() -> __blk_mq_sched_dispatch_requests(). |
590 | * | |
ca11f209 | 591 | * One confusing aspect here is that we get called for a specific |
7211aef8 | 592 | * hardware queue, but we may return a request that is for a |
ca11f209 JA |
593 | * different hardware queue. This is because mq-deadline has shared |
594 | * state for all hardware queues, in terms of sorting, FIFOs, etc. | |
595 | */ | |
c13660a0 | 596 | static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx) |
945ffb60 JA |
597 | { |
598 | struct deadline_data *dd = hctx->queue->elevator->elevator_data; | |
322cff70 | 599 | const unsigned long now = jiffies; |
7b05bf77 | 600 | struct request *rq; |
c807ab52 | 601 | enum dd_prio prio; |
945ffb60 JA |
602 | |
603 | spin_lock(&dd->lock); | |
322cff70 BVA |
604 | rq = dd_dispatch_prio_aged_requests(dd, now); |
605 | 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 | */ | |
fb926032 | 612 | for (prio = 0; prio <= DD_PRIO_MAX; prio++) { |
322cff70 BVA |
613 | rq = __dd_dispatch_request(dd, &dd->per_prio[prio], now); |
614 | if (rq || dd_queued(dd, prio)) | |
c807ab52 BVA |
615 | break; |
616 | } | |
322cff70 BVA |
617 | |
618 | unlock: | |
945ffb60 | 619 | spin_unlock(&dd->lock); |
c13660a0 JA |
620 | |
621 | return rq; | |
945ffb60 JA |
622 | } |
623 | ||
07757588 BVA |
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 | */ | |
f8359efe | 628 | static void dd_limit_depth(blk_opf_t opf, struct blk_mq_alloc_data *data) |
07757588 BVA |
629 | { |
630 | struct deadline_data *dd = data->q->elevator->elevator_data; | |
631 | ||
632 | /* Do not throttle synchronous reads. */ | |
f8359efe | 633 | if (op_is_sync(opf) && !op_is_write(opf)) |
07757588 BVA |
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 | data->shallow_depth = dd->async_depth; | |
641 | } | |
642 | ||
643 | /* Called by blk_mq_update_nr_requests(). */ | |
644 | static void dd_depth_updated(struct blk_mq_hw_ctx *hctx) | |
645 | { | |
646 | struct request_queue *q = hctx->queue; | |
647 | struct deadline_data *dd = q->elevator->elevator_data; | |
648 | struct blk_mq_tags *tags = hctx->sched_tags; | |
649 | ||
650 | dd->async_depth = max(1UL, 3 * q->nr_requests / 4); | |
651 | ||
ae0f1a73 | 652 | sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, dd->async_depth); |
07757588 BVA |
653 | } |
654 | ||
655 | /* Called by blk_mq_init_hctx() and blk_mq_init_sched(). */ | |
656 | static int dd_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
657 | { | |
658 | dd_depth_updated(hctx); | |
659 | return 0; | |
660 | } | |
661 | ||
3e9a99eb | 662 | static void dd_exit_sched(struct elevator_queue *e) |
945ffb60 JA |
663 | { |
664 | struct deadline_data *dd = e->elevator_data; | |
c807ab52 | 665 | enum dd_prio prio; |
945ffb60 | 666 | |
c807ab52 BVA |
667 | for (prio = 0; prio <= DD_PRIO_MAX; prio++) { |
668 | struct dd_per_prio *per_prio = &dd->per_prio[prio]; | |
bce0363e BVA |
669 | const struct io_stats_per_prio *stats = &per_prio->stats; |
670 | uint32_t queued; | |
c807ab52 BVA |
671 | |
672 | WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_READ])); | |
673 | WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_WRITE])); | |
bce0363e BVA |
674 | |
675 | spin_lock(&dd->lock); | |
676 | queued = dd_queued(dd, prio); | |
677 | spin_unlock(&dd->lock); | |
678 | ||
679 | WARN_ONCE(queued != 0, | |
32f64cad | 680 | "statistics for priority %d: i %u m %u d %u c %u\n", |
bce0363e BVA |
681 | prio, stats->inserted, stats->merged, |
682 | stats->dispatched, atomic_read(&stats->completed)); | |
c807ab52 | 683 | } |
945ffb60 JA |
684 | |
685 | kfree(dd); | |
686 | } | |
687 | ||
688 | /* | |
0f783995 | 689 | * initialize elevator private data (deadline_data). |
945ffb60 | 690 | */ |
3e9a99eb | 691 | static int dd_init_sched(struct request_queue *q, struct elevator_type *e) |
945ffb60 JA |
692 | { |
693 | struct deadline_data *dd; | |
694 | struct elevator_queue *eq; | |
c807ab52 BVA |
695 | enum dd_prio prio; |
696 | int ret = -ENOMEM; | |
945ffb60 JA |
697 | |
698 | eq = elevator_alloc(q, e); | |
699 | if (!eq) | |
c807ab52 | 700 | return ret; |
945ffb60 JA |
701 | |
702 | dd = kzalloc_node(sizeof(*dd), GFP_KERNEL, q->node); | |
c807ab52 BVA |
703 | if (!dd) |
704 | goto put_eq; | |
705 | ||
945ffb60 JA |
706 | eq->elevator_data = dd; |
707 | ||
c807ab52 BVA |
708 | for (prio = 0; prio <= DD_PRIO_MAX; prio++) { |
709 | struct dd_per_prio *per_prio = &dd->per_prio[prio]; | |
710 | ||
711 | INIT_LIST_HEAD(&per_prio->dispatch); | |
712 | INIT_LIST_HEAD(&per_prio->fifo_list[DD_READ]); | |
713 | INIT_LIST_HEAD(&per_prio->fifo_list[DD_WRITE]); | |
714 | per_prio->sort_list[DD_READ] = RB_ROOT; | |
715 | per_prio->sort_list[DD_WRITE] = RB_ROOT; | |
716 | } | |
004a26b3 BVA |
717 | dd->fifo_expire[DD_READ] = read_expire; |
718 | dd->fifo_expire[DD_WRITE] = write_expire; | |
945ffb60 JA |
719 | dd->writes_starved = writes_starved; |
720 | dd->front_merges = 1; | |
d672d325 | 721 | dd->last_dir = DD_WRITE; |
945ffb60 | 722 | dd->fifo_batch = fifo_batch; |
322cff70 | 723 | dd->prio_aging_expire = prio_aging_expire; |
945ffb60 | 724 | spin_lock_init(&dd->lock); |
5700f691 | 725 | spin_lock_init(&dd->zone_lock); |
945ffb60 | 726 | |
4d337ceb ML |
727 | /* We dispatch from request queue wide instead of hw queue */ |
728 | blk_queue_flag_set(QUEUE_FLAG_SQ_SCHED, q); | |
729 | ||
945ffb60 JA |
730 | q->elevator = eq; |
731 | return 0; | |
c807ab52 BVA |
732 | |
733 | put_eq: | |
734 | kobject_put(&eq->kobj); | |
735 | return ret; | |
945ffb60 JA |
736 | } |
737 | ||
46eae2e3 BVA |
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 | */ | |
945ffb60 JA |
742 | static int dd_request_merge(struct request_queue *q, struct request **rq, |
743 | struct bio *bio) | |
744 | { | |
745 | struct deadline_data *dd = q->elevator->elevator_data; | |
c807ab52 BVA |
746 | const u8 ioprio_class = IOPRIO_PRIO_CLASS(bio->bi_ioprio); |
747 | const enum dd_prio prio = ioprio_class_to_prio[ioprio_class]; | |
748 | struct dd_per_prio *per_prio = &dd->per_prio[prio]; | |
945ffb60 JA |
749 | sector_t sector = bio_end_sector(bio); |
750 | struct request *__rq; | |
751 | ||
752 | if (!dd->front_merges) | |
753 | return ELEVATOR_NO_MERGE; | |
754 | ||
c807ab52 | 755 | __rq = elv_rb_find(&per_prio->sort_list[bio_data_dir(bio)], sector); |
945ffb60 JA |
756 | if (__rq) { |
757 | BUG_ON(sector != blk_rq_pos(__rq)); | |
758 | ||
759 | if (elv_bio_merge_ok(__rq, bio)) { | |
760 | *rq = __rq; | |
866663b7 ML |
761 | if (blk_discard_mergable(__rq)) |
762 | return ELEVATOR_DISCARD_MERGE; | |
945ffb60 JA |
763 | return ELEVATOR_FRONT_MERGE; |
764 | } | |
765 | } | |
766 | ||
767 | return ELEVATOR_NO_MERGE; | |
768 | } | |
769 | ||
46eae2e3 BVA |
770 | /* |
771 | * Attempt to merge a bio into an existing request. This function is called | |
772 | * before @bio is associated with a request. | |
773 | */ | |
efed9a33 | 774 | static bool dd_bio_merge(struct request_queue *q, struct bio *bio, |
14ccb66b | 775 | unsigned int nr_segs) |
945ffb60 | 776 | { |
945ffb60 | 777 | struct deadline_data *dd = q->elevator->elevator_data; |
e4d750c9 JA |
778 | struct request *free = NULL; |
779 | bool ret; | |
945ffb60 JA |
780 | |
781 | spin_lock(&dd->lock); | |
14ccb66b | 782 | ret = blk_mq_sched_try_merge(q, bio, nr_segs, &free); |
945ffb60 JA |
783 | spin_unlock(&dd->lock); |
784 | ||
e4d750c9 JA |
785 | if (free) |
786 | blk_mq_free_request(free); | |
787 | ||
945ffb60 JA |
788 | return ret; |
789 | } | |
790 | ||
791 | /* | |
792 | * add rq to rbtree and fifo | |
793 | */ | |
794 | static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, | |
b2097bd2 | 795 | blk_insert_t flags, struct list_head *free) |
945ffb60 JA |
796 | { |
797 | struct request_queue *q = hctx->queue; | |
798 | struct deadline_data *dd = q->elevator->elevator_data; | |
004a26b3 | 799 | const enum dd_data_dir data_dir = rq_data_dir(rq); |
c807ab52 BVA |
800 | u16 ioprio = req_get_ioprio(rq); |
801 | u8 ioprio_class = IOPRIO_PRIO_CLASS(ioprio); | |
802 | struct dd_per_prio *per_prio; | |
803 | enum dd_prio prio; | |
945ffb60 | 804 | |
3bd473f4 BVA |
805 | lockdep_assert_held(&dd->lock); |
806 | ||
5700f691 DLM |
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 | blk_req_zone_write_unlock(rq); | |
812 | ||
c807ab52 | 813 | prio = ioprio_class_to_prio[ioprio_class]; |
bce0363e | 814 | per_prio = &dd->per_prio[prio]; |
e2c7275d | 815 | if (!rq->elv.priv[0]) { |
bce0363e | 816 | per_prio->stats.inserted++; |
e2c7275d BVA |
817 | rq->elv.priv[0] = (void *)(uintptr_t)1; |
818 | } | |
c807ab52 | 819 | |
b2097bd2 | 820 | if (blk_mq_sched_try_insert_merge(q, rq, free)) |
945ffb60 JA |
821 | return; |
822 | ||
b357e4a6 | 823 | trace_block_rq_insert(rq); |
945ffb60 | 824 | |
93fffe16 | 825 | if (flags & BLK_MQ_INSERT_AT_HEAD) { |
c807ab52 | 826 | list_add(&rq->queuelist, &per_prio->dispatch); |
725f22a1 | 827 | rq->fifo_time = jiffies; |
945ffb60 | 828 | } else { |
0effb390 BVA |
829 | struct list_head *insert_before; |
830 | ||
c807ab52 | 831 | deadline_add_rq_rb(per_prio, rq); |
945ffb60 JA |
832 | |
833 | if (rq_mergeable(rq)) { | |
834 | elv_rqhash_add(q, rq); | |
835 | if (!q->last_merge) | |
836 | q->last_merge = rq; | |
837 | } | |
838 | ||
839 | /* | |
840 | * set expire time and add to fifo list | |
841 | */ | |
842 | rq->fifo_time = jiffies + dd->fifo_expire[data_dir]; | |
0effb390 BVA |
843 | 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 | list_add_tail(&rq->queuelist, insert_before); | |
945ffb60 JA |
857 | } |
858 | } | |
859 | ||
46eae2e3 | 860 | /* |
2bd215df | 861 | * Called from blk_mq_insert_request() or blk_mq_dispatch_plug_list(). |
46eae2e3 | 862 | */ |
945ffb60 | 863 | static void dd_insert_requests(struct blk_mq_hw_ctx *hctx, |
93fffe16 CH |
864 | struct list_head *list, |
865 | blk_insert_t flags) | |
945ffb60 JA |
866 | { |
867 | struct request_queue *q = hctx->queue; | |
868 | struct deadline_data *dd = q->elevator->elevator_data; | |
b2097bd2 | 869 | LIST_HEAD(free); |
945ffb60 JA |
870 | |
871 | spin_lock(&dd->lock); | |
872 | while (!list_empty(list)) { | |
873 | struct request *rq; | |
874 | ||
875 | rq = list_first_entry(list, struct request, queuelist); | |
876 | list_del_init(&rq->queuelist); | |
b2097bd2 | 877 | dd_insert_request(hctx, rq, flags, &free); |
945ffb60 JA |
878 | } |
879 | spin_unlock(&dd->lock); | |
b2097bd2 BVA |
880 | |
881 | blk_mq_free_requests(&free); | |
945ffb60 JA |
882 | } |
883 | ||
b6d2b054 | 884 | /* Callback from inside blk_mq_rq_ctx_init(). */ |
5d9c305b | 885 | static void dd_prepare_request(struct request *rq) |
f3bc78d2 | 886 | { |
b6d2b054 | 887 | rq->elv.priv[0] = NULL; |
f3bc78d2 DLM |
888 | } |
889 | ||
2820e5d0 DLM |
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 | ||
5700f691 | 902 | /* |
46eae2e3 BVA |
903 | * Callback from inside blk_mq_free_request(). |
904 | * | |
5700f691 DLM |
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() | |
f3bc78d2 DLM |
908 | * or deadline_next_request() are executing. This function is called for |
909 | * all requests, whether or not these requests complete successfully. | |
cb8acabb DLM |
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. | |
5700f691 | 917 | */ |
f3bc78d2 | 918 | static void dd_finish_request(struct request *rq) |
5700f691 DLM |
919 | { |
920 | struct request_queue *q = rq->q; | |
c807ab52 BVA |
921 | struct deadline_data *dd = q->elevator->elevator_data; |
922 | const u8 ioprio_class = dd_rq_ioclass(rq); | |
923 | const enum dd_prio prio = ioprio_class_to_prio[ioprio_class]; | |
924 | struct dd_per_prio *per_prio = &dd->per_prio[prio]; | |
5700f691 | 925 | |
b6d2b054 BVA |
926 | /* |
927 | * The block layer core may call dd_finish_request() without having | |
e2c7275d BVA |
928 | * called dd_insert_requests(). Skip requests that bypassed I/O |
929 | * scheduling. See also blk_mq_request_bypass_insert(). | |
b6d2b054 | 930 | */ |
e2c7275d BVA |
931 | if (!rq->elv.priv[0]) |
932 | return; | |
933 | ||
bce0363e | 934 | atomic_inc(&per_prio->stats.completed); |
38ba64d1 | 935 | |
5700f691 | 936 | if (blk_queue_is_zoned(q)) { |
5700f691 DLM |
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); | |
2820e5d0 DLM |
942 | |
943 | if (dd_has_write_work(rq->mq_hctx)) | |
944 | blk_mq_sched_mark_restart_hctx(rq->mq_hctx); | |
5700f691 DLM |
945 | } |
946 | } | |
947 | ||
c807ab52 BVA |
948 | static bool dd_has_work_for_prio(struct dd_per_prio *per_prio) |
949 | { | |
950 | return !list_empty_careful(&per_prio->dispatch) || | |
951 | !list_empty_careful(&per_prio->fifo_list[DD_READ]) || | |
952 | !list_empty_careful(&per_prio->fifo_list[DD_WRITE]); | |
953 | } | |
954 | ||
945ffb60 JA |
955 | static bool dd_has_work(struct blk_mq_hw_ctx *hctx) |
956 | { | |
957 | struct deadline_data *dd = hctx->queue->elevator->elevator_data; | |
c807ab52 BVA |
958 | enum dd_prio prio; |
959 | ||
960 | for (prio = 0; prio <= DD_PRIO_MAX; prio++) | |
961 | if (dd_has_work_for_prio(&dd->per_prio[prio])) | |
962 | return true; | |
945ffb60 | 963 | |
c807ab52 | 964 | return false; |
945ffb60 JA |
965 | } |
966 | ||
967 | /* | |
968 | * sysfs parts below | |
969 | */ | |
d6d7f013 | 970 | #define SHOW_INT(__FUNC, __VAR) \ |
945ffb60 JA |
971 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
972 | { \ | |
973 | struct deadline_data *dd = e->elevator_data; \ | |
d6d7f013 BVA |
974 | \ |
975 | return sysfs_emit(page, "%d\n", __VAR); \ | |
945ffb60 | 976 | } |
d6d7f013 BVA |
977 | #define SHOW_JIFFIES(__FUNC, __VAR) SHOW_INT(__FUNC, jiffies_to_msecs(__VAR)) |
978 | SHOW_JIFFIES(deadline_read_expire_show, dd->fifo_expire[DD_READ]); | |
979 | SHOW_JIFFIES(deadline_write_expire_show, dd->fifo_expire[DD_WRITE]); | |
322cff70 | 980 | SHOW_JIFFIES(deadline_prio_aging_expire_show, dd->prio_aging_expire); |
d6d7f013 BVA |
981 | SHOW_INT(deadline_writes_starved_show, dd->writes_starved); |
982 | SHOW_INT(deadline_front_merges_show, dd->front_merges); | |
46cdc45a | 983 | SHOW_INT(deadline_async_depth_show, dd->async_depth); |
d6d7f013 BVA |
984 | SHOW_INT(deadline_fifo_batch_show, dd->fifo_batch); |
985 | #undef SHOW_INT | |
986 | #undef SHOW_JIFFIES | |
945ffb60 JA |
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; \ | |
d6d7f013 BVA |
992 | int __data, __ret; \ |
993 | \ | |
994 | __ret = kstrtoint(page, 0, &__data); \ | |
995 | if (__ret < 0) \ | |
996 | return __ret; \ | |
945ffb60 JA |
997 | if (__data < (MIN)) \ |
998 | __data = (MIN); \ | |
999 | else if (__data > (MAX)) \ | |
1000 | __data = (MAX); \ | |
d6d7f013 | 1001 | *(__PTR) = __CONV(__data); \ |
235f8da1 | 1002 | return count; \ |
945ffb60 | 1003 | } |
d6d7f013 BVA |
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 | STORE_JIFFIES(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX); | |
1009 | STORE_JIFFIES(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX); | |
322cff70 | 1010 | STORE_JIFFIES(deadline_prio_aging_expire_store, &dd->prio_aging_expire, 0, INT_MAX); |
d6d7f013 BVA |
1011 | STORE_INT(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX); |
1012 | STORE_INT(deadline_front_merges_store, &dd->front_merges, 0, 1); | |
46cdc45a | 1013 | STORE_INT(deadline_async_depth_store, &dd->async_depth, 1, INT_MAX); |
d6d7f013 | 1014 | STORE_INT(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX); |
945ffb60 | 1015 | #undef STORE_FUNCTION |
d6d7f013 BVA |
1016 | #undef STORE_INT |
1017 | #undef STORE_JIFFIES | |
945ffb60 JA |
1018 | |
1019 | #define DD_ATTR(name) \ | |
5657a819 | 1020 | __ATTR(name, 0644, deadline_##name##_show, deadline_##name##_store) |
945ffb60 JA |
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), | |
07757588 | 1027 | DD_ATTR(async_depth), |
945ffb60 | 1028 | DD_ATTR(fifo_batch), |
322cff70 | 1029 | DD_ATTR(prio_aging_expire), |
945ffb60 JA |
1030 | __ATTR_NULL |
1031 | }; | |
1032 | ||
daaadb3e | 1033 | #ifdef CONFIG_BLK_DEBUG_FS |
c807ab52 | 1034 | #define DEADLINE_DEBUGFS_DDIR_ATTRS(prio, data_dir, name) \ |
daaadb3e OS |
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; \ | |
c807ab52 | 1041 | struct dd_per_prio *per_prio = &dd->per_prio[prio]; \ |
daaadb3e OS |
1042 | \ |
1043 | spin_lock(&dd->lock); \ | |
c807ab52 | 1044 | return seq_list_start(&per_prio->fifo_list[data_dir], *pos); \ |
daaadb3e OS |
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; \ | |
c807ab52 | 1052 | struct dd_per_prio *per_prio = &dd->per_prio[prio]; \ |
daaadb3e | 1053 | \ |
c807ab52 | 1054 | return seq_list_next(v, &per_prio->fifo_list[data_dir], pos); \ |
daaadb3e OS |
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; \ | |
c807ab52 | 1078 | struct dd_per_prio *per_prio = &dd->per_prio[prio]; \ |
83c46ed6 | 1079 | struct request *rq; \ |
daaadb3e | 1080 | \ |
83c46ed6 BVA |
1081 | rq = deadline_from_pos(per_prio, data_dir, \ |
1082 | per_prio->latest_pos[data_dir]); \ | |
daaadb3e OS |
1083 | if (rq) \ |
1084 | __blk_mq_debugfs_rq_show(m, rq); \ | |
1085 | return 0; \ | |
1086 | } | |
c807ab52 BVA |
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); | |
daaadb3e OS |
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 | ||
07757588 BVA |
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 | ||
38ba64d1 BVA |
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; | |
bce0363e BVA |
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); | |
38ba64d1 | 1136 | |
38ba64d1 BVA |
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 | { | |
bce0363e BVA |
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); | |
38ba64d1 BVA |
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; | |
bce0363e BVA |
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); | |
38ba64d1 | 1164 | |
38ba64d1 BVA |
1165 | return 0; |
1166 | } | |
1167 | ||
c807ab52 BVA |
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, \ | |
daaadb3e OS |
1205 | } |
1206 | ||
c807ab52 BVA |
1207 | DEADLINE_DISPATCH_ATTR(0); |
1208 | DEADLINE_DISPATCH_ATTR(1); | |
1209 | DEADLINE_DISPATCH_ATTR(2); | |
1210 | #undef DEADLINE_DISPATCH_ATTR | |
daaadb3e | 1211 | |
c807ab52 BVA |
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) \ | |
daaadb3e OS |
1216 | {#name "_next_rq", 0400, deadline_##name##_next_rq_show} |
1217 | static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = { | |
c807ab52 BVA |
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), | |
daaadb3e OS |
1230 | {"batching", 0400, deadline_batching_show}, |
1231 | {"starved", 0400, deadline_starved_show}, | |
07757588 | 1232 | {"async_depth", 0400, dd_async_depth_show}, |
c807ab52 BVA |
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}, | |
38ba64d1 BVA |
1236 | {"owned_by_driver", 0400, dd_owned_by_driver_show}, |
1237 | {"queued", 0400, dd_queued_show}, | |
daaadb3e OS |
1238 | {}, |
1239 | }; | |
1240 | #undef DEADLINE_QUEUE_DDIR_ATTRS | |
1241 | #endif | |
1242 | ||
945ffb60 | 1243 | static struct elevator_type mq_deadline = { |
f9cd4bfe | 1244 | .ops = { |
07757588 BVA |
1245 | .depth_updated = dd_depth_updated, |
1246 | .limit_depth = dd_limit_depth, | |
945ffb60 | 1247 | .insert_requests = dd_insert_requests, |
c13660a0 | 1248 | .dispatch_request = dd_dispatch_request, |
f3bc78d2 DLM |
1249 | .prepare_request = dd_prepare_request, |
1250 | .finish_request = dd_finish_request, | |
945ffb60 JA |
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, | |
3e9a99eb BVA |
1258 | .init_sched = dd_init_sched, |
1259 | .exit_sched = dd_exit_sched, | |
07757588 | 1260 | .init_hctx = dd_init_hctx, |
945ffb60 JA |
1261 | }, |
1262 | ||
daaadb3e OS |
1263 | #ifdef CONFIG_BLK_DEBUG_FS |
1264 | .queue_debugfs_attrs = deadline_queue_debugfs_attrs, | |
1265 | #endif | |
945ffb60 JA |
1266 | .elevator_attrs = deadline_attrs, |
1267 | .elevator_name = "mq-deadline", | |
4d740bc9 | 1268 | .elevator_alias = "deadline", |
68c43f13 | 1269 | .elevator_features = ELEVATOR_F_ZBD_SEQ_WRITE, |
945ffb60 JA |
1270 | .elevator_owner = THIS_MODULE, |
1271 | }; | |
7de967e7 | 1272 | MODULE_ALIAS("mq-deadline-iosched"); |
945ffb60 JA |
1273 | |
1274 | static int __init deadline_init(void) | |
1275 | { | |
0f783995 | 1276 | return elv_register(&mq_deadline); |
945ffb60 JA |
1277 | } |
1278 | ||
1279 | static void __exit deadline_exit(void) | |
1280 | { | |
1281 | elv_unregister(&mq_deadline); | |
1282 | } | |
1283 | ||
1284 | module_init(deadline_init); | |
1285 | module_exit(deadline_exit); | |
1286 | ||
c807ab52 | 1287 | MODULE_AUTHOR("Jens Axboe, Damien Le Moal and Bart Van Assche"); |
945ffb60 JA |
1288 | MODULE_LICENSE("GPL"); |
1289 | MODULE_DESCRIPTION("MQ deadline IO scheduler"); |