]>
Commit | Line | Data |
---|---|---|
1 | /* | |
2 | * CFQ, or complete fairness queueing, disk scheduler. | |
3 | * | |
4 | * Based on ideas from a previously unfinished io | |
5 | * scheduler (round robin per-process disk scheduling) and Andrea Arcangeli. | |
6 | * | |
7 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> | |
8 | */ | |
9 | #include <linux/module.h> | |
10 | #include <linux/slab.h> | |
11 | #include <linux/sched/clock.h> | |
12 | #include <linux/blkdev.h> | |
13 | #include <linux/elevator.h> | |
14 | #include <linux/ktime.h> | |
15 | #include <linux/rbtree.h> | |
16 | #include <linux/ioprio.h> | |
17 | #include <linux/blktrace_api.h> | |
18 | #include <linux/blk-cgroup.h> | |
19 | #include "blk.h" | |
20 | #include "blk-wbt.h" | |
21 | ||
22 | /* | |
23 | * tunables | |
24 | */ | |
25 | /* max queue in one round of service */ | |
26 | static const int cfq_quantum = 8; | |
27 | static const u64 cfq_fifo_expire[2] = { NSEC_PER_SEC / 4, NSEC_PER_SEC / 8 }; | |
28 | /* maximum backwards seek, in KiB */ | |
29 | static const int cfq_back_max = 16 * 1024; | |
30 | /* penalty of a backwards seek */ | |
31 | static const int cfq_back_penalty = 2; | |
32 | static const u64 cfq_slice_sync = NSEC_PER_SEC / 10; | |
33 | static u64 cfq_slice_async = NSEC_PER_SEC / 25; | |
34 | static const int cfq_slice_async_rq = 2; | |
35 | static u64 cfq_slice_idle = NSEC_PER_SEC / 125; | |
36 | static u64 cfq_group_idle = NSEC_PER_SEC / 125; | |
37 | static const u64 cfq_target_latency = (u64)NSEC_PER_SEC * 3/10; /* 300 ms */ | |
38 | static const int cfq_hist_divisor = 4; | |
39 | ||
40 | /* | |
41 | * offset from end of service tree | |
42 | */ | |
43 | #define CFQ_IDLE_DELAY (NSEC_PER_SEC / 5) | |
44 | ||
45 | /* | |
46 | * below this threshold, we consider thinktime immediate | |
47 | */ | |
48 | #define CFQ_MIN_TT (2 * NSEC_PER_SEC / HZ) | |
49 | ||
50 | #define CFQ_SLICE_SCALE (5) | |
51 | #define CFQ_HW_QUEUE_MIN (5) | |
52 | #define CFQ_SERVICE_SHIFT 12 | |
53 | ||
54 | #define CFQQ_SEEK_THR (sector_t)(8 * 100) | |
55 | #define CFQQ_CLOSE_THR (sector_t)(8 * 1024) | |
56 | #define CFQQ_SECT_THR_NONROT (sector_t)(2 * 32) | |
57 | #define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8) | |
58 | ||
59 | #define RQ_CIC(rq) icq_to_cic((rq)->elv.icq) | |
60 | #define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elv.priv[0]) | |
61 | #define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elv.priv[1]) | |
62 | ||
63 | static struct kmem_cache *cfq_pool; | |
64 | ||
65 | #define CFQ_PRIO_LISTS IOPRIO_BE_NR | |
66 | #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE) | |
67 | #define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT) | |
68 | ||
69 | #define sample_valid(samples) ((samples) > 80) | |
70 | #define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node) | |
71 | ||
72 | /* blkio-related constants */ | |
73 | #define CFQ_WEIGHT_LEGACY_MIN 10 | |
74 | #define CFQ_WEIGHT_LEGACY_DFL 500 | |
75 | #define CFQ_WEIGHT_LEGACY_MAX 1000 | |
76 | ||
77 | struct cfq_ttime { | |
78 | u64 last_end_request; | |
79 | ||
80 | u64 ttime_total; | |
81 | u64 ttime_mean; | |
82 | unsigned long ttime_samples; | |
83 | }; | |
84 | ||
85 | /* | |
86 | * Most of our rbtree usage is for sorting with min extraction, so | |
87 | * if we cache the leftmost node we don't have to walk down the tree | |
88 | * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should | |
89 | * move this into the elevator for the rq sorting as well. | |
90 | */ | |
91 | struct cfq_rb_root { | |
92 | struct rb_root rb; | |
93 | struct rb_node *left; | |
94 | unsigned count; | |
95 | u64 min_vdisktime; | |
96 | struct cfq_ttime ttime; | |
97 | }; | |
98 | #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, \ | |
99 | .ttime = {.last_end_request = ktime_get_ns(),},} | |
100 | ||
101 | /* | |
102 | * Per process-grouping structure | |
103 | */ | |
104 | struct cfq_queue { | |
105 | /* reference count */ | |
106 | int ref; | |
107 | /* various state flags, see below */ | |
108 | unsigned int flags; | |
109 | /* parent cfq_data */ | |
110 | struct cfq_data *cfqd; | |
111 | /* service_tree member */ | |
112 | struct rb_node rb_node; | |
113 | /* service_tree key */ | |
114 | u64 rb_key; | |
115 | /* prio tree member */ | |
116 | struct rb_node p_node; | |
117 | /* prio tree root we belong to, if any */ | |
118 | struct rb_root *p_root; | |
119 | /* sorted list of pending requests */ | |
120 | struct rb_root sort_list; | |
121 | /* if fifo isn't expired, next request to serve */ | |
122 | struct request *next_rq; | |
123 | /* requests queued in sort_list */ | |
124 | int queued[2]; | |
125 | /* currently allocated requests */ | |
126 | int allocated[2]; | |
127 | /* fifo list of requests in sort_list */ | |
128 | struct list_head fifo; | |
129 | ||
130 | /* time when queue got scheduled in to dispatch first request. */ | |
131 | u64 dispatch_start; | |
132 | u64 allocated_slice; | |
133 | u64 slice_dispatch; | |
134 | /* time when first request from queue completed and slice started. */ | |
135 | u64 slice_start; | |
136 | u64 slice_end; | |
137 | s64 slice_resid; | |
138 | ||
139 | /* pending priority requests */ | |
140 | int prio_pending; | |
141 | /* number of requests that are on the dispatch list or inside driver */ | |
142 | int dispatched; | |
143 | ||
144 | /* io prio of this group */ | |
145 | unsigned short ioprio, org_ioprio; | |
146 | unsigned short ioprio_class, org_ioprio_class; | |
147 | ||
148 | pid_t pid; | |
149 | ||
150 | u32 seek_history; | |
151 | sector_t last_request_pos; | |
152 | ||
153 | struct cfq_rb_root *service_tree; | |
154 | struct cfq_queue *new_cfqq; | |
155 | struct cfq_group *cfqg; | |
156 | /* Number of sectors dispatched from queue in single dispatch round */ | |
157 | unsigned long nr_sectors; | |
158 | }; | |
159 | ||
160 | /* | |
161 | * First index in the service_trees. | |
162 | * IDLE is handled separately, so it has negative index | |
163 | */ | |
164 | enum wl_class_t { | |
165 | BE_WORKLOAD = 0, | |
166 | RT_WORKLOAD = 1, | |
167 | IDLE_WORKLOAD = 2, | |
168 | CFQ_PRIO_NR, | |
169 | }; | |
170 | ||
171 | /* | |
172 | * Second index in the service_trees. | |
173 | */ | |
174 | enum wl_type_t { | |
175 | ASYNC_WORKLOAD = 0, | |
176 | SYNC_NOIDLE_WORKLOAD = 1, | |
177 | SYNC_WORKLOAD = 2 | |
178 | }; | |
179 | ||
180 | struct cfqg_stats { | |
181 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
182 | /* number of ios merged */ | |
183 | struct blkg_rwstat merged; | |
184 | /* total time spent on device in ns, may not be accurate w/ queueing */ | |
185 | struct blkg_rwstat service_time; | |
186 | /* total time spent waiting in scheduler queue in ns */ | |
187 | struct blkg_rwstat wait_time; | |
188 | /* number of IOs queued up */ | |
189 | struct blkg_rwstat queued; | |
190 | /* total disk time and nr sectors dispatched by this group */ | |
191 | struct blkg_stat time; | |
192 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
193 | /* time not charged to this cgroup */ | |
194 | struct blkg_stat unaccounted_time; | |
195 | /* sum of number of ios queued across all samples */ | |
196 | struct blkg_stat avg_queue_size_sum; | |
197 | /* count of samples taken for average */ | |
198 | struct blkg_stat avg_queue_size_samples; | |
199 | /* how many times this group has been removed from service tree */ | |
200 | struct blkg_stat dequeue; | |
201 | /* total time spent waiting for it to be assigned a timeslice. */ | |
202 | struct blkg_stat group_wait_time; | |
203 | /* time spent idling for this blkcg_gq */ | |
204 | struct blkg_stat idle_time; | |
205 | /* total time with empty current active q with other requests queued */ | |
206 | struct blkg_stat empty_time; | |
207 | /* fields after this shouldn't be cleared on stat reset */ | |
208 | uint64_t start_group_wait_time; | |
209 | uint64_t start_idle_time; | |
210 | uint64_t start_empty_time; | |
211 | uint16_t flags; | |
212 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
213 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ | |
214 | }; | |
215 | ||
216 | /* Per-cgroup data */ | |
217 | struct cfq_group_data { | |
218 | /* must be the first member */ | |
219 | struct blkcg_policy_data cpd; | |
220 | ||
221 | unsigned int weight; | |
222 | unsigned int leaf_weight; | |
223 | }; | |
224 | ||
225 | /* This is per cgroup per device grouping structure */ | |
226 | struct cfq_group { | |
227 | /* must be the first member */ | |
228 | struct blkg_policy_data pd; | |
229 | ||
230 | /* group service_tree member */ | |
231 | struct rb_node rb_node; | |
232 | ||
233 | /* group service_tree key */ | |
234 | u64 vdisktime; | |
235 | ||
236 | /* | |
237 | * The number of active cfqgs and sum of their weights under this | |
238 | * cfqg. This covers this cfqg's leaf_weight and all children's | |
239 | * weights, but does not cover weights of further descendants. | |
240 | * | |
241 | * If a cfqg is on the service tree, it's active. An active cfqg | |
242 | * also activates its parent and contributes to the children_weight | |
243 | * of the parent. | |
244 | */ | |
245 | int nr_active; | |
246 | unsigned int children_weight; | |
247 | ||
248 | /* | |
249 | * vfraction is the fraction of vdisktime that the tasks in this | |
250 | * cfqg are entitled to. This is determined by compounding the | |
251 | * ratios walking up from this cfqg to the root. | |
252 | * | |
253 | * It is in fixed point w/ CFQ_SERVICE_SHIFT and the sum of all | |
254 | * vfractions on a service tree is approximately 1. The sum may | |
255 | * deviate a bit due to rounding errors and fluctuations caused by | |
256 | * cfqgs entering and leaving the service tree. | |
257 | */ | |
258 | unsigned int vfraction; | |
259 | ||
260 | /* | |
261 | * There are two weights - (internal) weight is the weight of this | |
262 | * cfqg against the sibling cfqgs. leaf_weight is the wight of | |
263 | * this cfqg against the child cfqgs. For the root cfqg, both | |
264 | * weights are kept in sync for backward compatibility. | |
265 | */ | |
266 | unsigned int weight; | |
267 | unsigned int new_weight; | |
268 | unsigned int dev_weight; | |
269 | ||
270 | unsigned int leaf_weight; | |
271 | unsigned int new_leaf_weight; | |
272 | unsigned int dev_leaf_weight; | |
273 | ||
274 | /* number of cfqq currently on this group */ | |
275 | int nr_cfqq; | |
276 | ||
277 | /* | |
278 | * Per group busy queues average. Useful for workload slice calc. We | |
279 | * create the array for each prio class but at run time it is used | |
280 | * only for RT and BE class and slot for IDLE class remains unused. | |
281 | * This is primarily done to avoid confusion and a gcc warning. | |
282 | */ | |
283 | unsigned int busy_queues_avg[CFQ_PRIO_NR]; | |
284 | /* | |
285 | * rr lists of queues with requests. We maintain service trees for | |
286 | * RT and BE classes. These trees are subdivided in subclasses | |
287 | * of SYNC, SYNC_NOIDLE and ASYNC based on workload type. For IDLE | |
288 | * class there is no subclassification and all the cfq queues go on | |
289 | * a single tree service_tree_idle. | |
290 | * Counts are embedded in the cfq_rb_root | |
291 | */ | |
292 | struct cfq_rb_root service_trees[2][3]; | |
293 | struct cfq_rb_root service_tree_idle; | |
294 | ||
295 | u64 saved_wl_slice; | |
296 | enum wl_type_t saved_wl_type; | |
297 | enum wl_class_t saved_wl_class; | |
298 | ||
299 | /* number of requests that are on the dispatch list or inside driver */ | |
300 | int dispatched; | |
301 | struct cfq_ttime ttime; | |
302 | struct cfqg_stats stats; /* stats for this cfqg */ | |
303 | ||
304 | /* async queue for each priority case */ | |
305 | struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; | |
306 | struct cfq_queue *async_idle_cfqq; | |
307 | ||
308 | }; | |
309 | ||
310 | struct cfq_io_cq { | |
311 | struct io_cq icq; /* must be the first member */ | |
312 | struct cfq_queue *cfqq[2]; | |
313 | struct cfq_ttime ttime; | |
314 | int ioprio; /* the current ioprio */ | |
315 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
316 | uint64_t blkcg_serial_nr; /* the current blkcg serial */ | |
317 | #endif | |
318 | }; | |
319 | ||
320 | /* | |
321 | * Per block device queue structure | |
322 | */ | |
323 | struct cfq_data { | |
324 | struct request_queue *queue; | |
325 | /* Root service tree for cfq_groups */ | |
326 | struct cfq_rb_root grp_service_tree; | |
327 | struct cfq_group *root_group; | |
328 | ||
329 | /* | |
330 | * The priority currently being served | |
331 | */ | |
332 | enum wl_class_t serving_wl_class; | |
333 | enum wl_type_t serving_wl_type; | |
334 | u64 workload_expires; | |
335 | struct cfq_group *serving_group; | |
336 | ||
337 | /* | |
338 | * Each priority tree is sorted by next_request position. These | |
339 | * trees are used when determining if two or more queues are | |
340 | * interleaving requests (see cfq_close_cooperator). | |
341 | */ | |
342 | struct rb_root prio_trees[CFQ_PRIO_LISTS]; | |
343 | ||
344 | unsigned int busy_queues; | |
345 | unsigned int busy_sync_queues; | |
346 | ||
347 | int rq_in_driver; | |
348 | int rq_in_flight[2]; | |
349 | ||
350 | /* | |
351 | * queue-depth detection | |
352 | */ | |
353 | int rq_queued; | |
354 | int hw_tag; | |
355 | /* | |
356 | * hw_tag can be | |
357 | * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection) | |
358 | * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth) | |
359 | * 0 => no NCQ | |
360 | */ | |
361 | int hw_tag_est_depth; | |
362 | unsigned int hw_tag_samples; | |
363 | ||
364 | /* | |
365 | * idle window management | |
366 | */ | |
367 | struct hrtimer idle_slice_timer; | |
368 | struct work_struct unplug_work; | |
369 | ||
370 | struct cfq_queue *active_queue; | |
371 | struct cfq_io_cq *active_cic; | |
372 | ||
373 | sector_t last_position; | |
374 | ||
375 | /* | |
376 | * tunables, see top of file | |
377 | */ | |
378 | unsigned int cfq_quantum; | |
379 | unsigned int cfq_back_penalty; | |
380 | unsigned int cfq_back_max; | |
381 | unsigned int cfq_slice_async_rq; | |
382 | unsigned int cfq_latency; | |
383 | u64 cfq_fifo_expire[2]; | |
384 | u64 cfq_slice[2]; | |
385 | u64 cfq_slice_idle; | |
386 | u64 cfq_group_idle; | |
387 | u64 cfq_target_latency; | |
388 | ||
389 | /* | |
390 | * Fallback dummy cfqq for extreme OOM conditions | |
391 | */ | |
392 | struct cfq_queue oom_cfqq; | |
393 | ||
394 | u64 last_delayed_sync; | |
395 | }; | |
396 | ||
397 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd); | |
398 | static void cfq_put_queue(struct cfq_queue *cfqq); | |
399 | ||
400 | static struct cfq_rb_root *st_for(struct cfq_group *cfqg, | |
401 | enum wl_class_t class, | |
402 | enum wl_type_t type) | |
403 | { | |
404 | if (!cfqg) | |
405 | return NULL; | |
406 | ||
407 | if (class == IDLE_WORKLOAD) | |
408 | return &cfqg->service_tree_idle; | |
409 | ||
410 | return &cfqg->service_trees[class][type]; | |
411 | } | |
412 | ||
413 | enum cfqq_state_flags { | |
414 | CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ | |
415 | CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ | |
416 | CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ | |
417 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ | |
418 | CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ | |
419 | CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ | |
420 | CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ | |
421 | CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ | |
422 | CFQ_CFQQ_FLAG_sync, /* synchronous queue */ | |
423 | CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ | |
424 | CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */ | |
425 | CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ | |
426 | CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ | |
427 | }; | |
428 | ||
429 | #define CFQ_CFQQ_FNS(name) \ | |
430 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ | |
431 | { \ | |
432 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ | |
433 | } \ | |
434 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ | |
435 | { \ | |
436 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ | |
437 | } \ | |
438 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ | |
439 | { \ | |
440 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ | |
441 | } | |
442 | ||
443 | CFQ_CFQQ_FNS(on_rr); | |
444 | CFQ_CFQQ_FNS(wait_request); | |
445 | CFQ_CFQQ_FNS(must_dispatch); | |
446 | CFQ_CFQQ_FNS(must_alloc_slice); | |
447 | CFQ_CFQQ_FNS(fifo_expire); | |
448 | CFQ_CFQQ_FNS(idle_window); | |
449 | CFQ_CFQQ_FNS(prio_changed); | |
450 | CFQ_CFQQ_FNS(slice_new); | |
451 | CFQ_CFQQ_FNS(sync); | |
452 | CFQ_CFQQ_FNS(coop); | |
453 | CFQ_CFQQ_FNS(split_coop); | |
454 | CFQ_CFQQ_FNS(deep); | |
455 | CFQ_CFQQ_FNS(wait_busy); | |
456 | #undef CFQ_CFQQ_FNS | |
457 | ||
458 | #if defined(CONFIG_CFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) | |
459 | ||
460 | /* cfqg stats flags */ | |
461 | enum cfqg_stats_flags { | |
462 | CFQG_stats_waiting = 0, | |
463 | CFQG_stats_idling, | |
464 | CFQG_stats_empty, | |
465 | }; | |
466 | ||
467 | #define CFQG_FLAG_FNS(name) \ | |
468 | static inline void cfqg_stats_mark_##name(struct cfqg_stats *stats) \ | |
469 | { \ | |
470 | stats->flags |= (1 << CFQG_stats_##name); \ | |
471 | } \ | |
472 | static inline void cfqg_stats_clear_##name(struct cfqg_stats *stats) \ | |
473 | { \ | |
474 | stats->flags &= ~(1 << CFQG_stats_##name); \ | |
475 | } \ | |
476 | static inline int cfqg_stats_##name(struct cfqg_stats *stats) \ | |
477 | { \ | |
478 | return (stats->flags & (1 << CFQG_stats_##name)) != 0; \ | |
479 | } \ | |
480 | ||
481 | CFQG_FLAG_FNS(waiting) | |
482 | CFQG_FLAG_FNS(idling) | |
483 | CFQG_FLAG_FNS(empty) | |
484 | #undef CFQG_FLAG_FNS | |
485 | ||
486 | /* This should be called with the queue_lock held. */ | |
487 | static void cfqg_stats_update_group_wait_time(struct cfqg_stats *stats) | |
488 | { | |
489 | unsigned long long now; | |
490 | ||
491 | if (!cfqg_stats_waiting(stats)) | |
492 | return; | |
493 | ||
494 | now = sched_clock(); | |
495 | if (time_after64(now, stats->start_group_wait_time)) | |
496 | blkg_stat_add(&stats->group_wait_time, | |
497 | now - stats->start_group_wait_time); | |
498 | cfqg_stats_clear_waiting(stats); | |
499 | } | |
500 | ||
501 | /* This should be called with the queue_lock held. */ | |
502 | static void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, | |
503 | struct cfq_group *curr_cfqg) | |
504 | { | |
505 | struct cfqg_stats *stats = &cfqg->stats; | |
506 | ||
507 | if (cfqg_stats_waiting(stats)) | |
508 | return; | |
509 | if (cfqg == curr_cfqg) | |
510 | return; | |
511 | stats->start_group_wait_time = sched_clock(); | |
512 | cfqg_stats_mark_waiting(stats); | |
513 | } | |
514 | ||
515 | /* This should be called with the queue_lock held. */ | |
516 | static void cfqg_stats_end_empty_time(struct cfqg_stats *stats) | |
517 | { | |
518 | unsigned long long now; | |
519 | ||
520 | if (!cfqg_stats_empty(stats)) | |
521 | return; | |
522 | ||
523 | now = sched_clock(); | |
524 | if (time_after64(now, stats->start_empty_time)) | |
525 | blkg_stat_add(&stats->empty_time, | |
526 | now - stats->start_empty_time); | |
527 | cfqg_stats_clear_empty(stats); | |
528 | } | |
529 | ||
530 | static void cfqg_stats_update_dequeue(struct cfq_group *cfqg) | |
531 | { | |
532 | blkg_stat_add(&cfqg->stats.dequeue, 1); | |
533 | } | |
534 | ||
535 | static void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) | |
536 | { | |
537 | struct cfqg_stats *stats = &cfqg->stats; | |
538 | ||
539 | if (blkg_rwstat_total(&stats->queued)) | |
540 | return; | |
541 | ||
542 | /* | |
543 | * group is already marked empty. This can happen if cfqq got new | |
544 | * request in parent group and moved to this group while being added | |
545 | * to service tree. Just ignore the event and move on. | |
546 | */ | |
547 | if (cfqg_stats_empty(stats)) | |
548 | return; | |
549 | ||
550 | stats->start_empty_time = sched_clock(); | |
551 | cfqg_stats_mark_empty(stats); | |
552 | } | |
553 | ||
554 | static void cfqg_stats_update_idle_time(struct cfq_group *cfqg) | |
555 | { | |
556 | struct cfqg_stats *stats = &cfqg->stats; | |
557 | ||
558 | if (cfqg_stats_idling(stats)) { | |
559 | unsigned long long now = sched_clock(); | |
560 | ||
561 | if (time_after64(now, stats->start_idle_time)) | |
562 | blkg_stat_add(&stats->idle_time, | |
563 | now - stats->start_idle_time); | |
564 | cfqg_stats_clear_idling(stats); | |
565 | } | |
566 | } | |
567 | ||
568 | static void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) | |
569 | { | |
570 | struct cfqg_stats *stats = &cfqg->stats; | |
571 | ||
572 | BUG_ON(cfqg_stats_idling(stats)); | |
573 | ||
574 | stats->start_idle_time = sched_clock(); | |
575 | cfqg_stats_mark_idling(stats); | |
576 | } | |
577 | ||
578 | static void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) | |
579 | { | |
580 | struct cfqg_stats *stats = &cfqg->stats; | |
581 | ||
582 | blkg_stat_add(&stats->avg_queue_size_sum, | |
583 | blkg_rwstat_total(&stats->queued)); | |
584 | blkg_stat_add(&stats->avg_queue_size_samples, 1); | |
585 | cfqg_stats_update_group_wait_time(stats); | |
586 | } | |
587 | ||
588 | #else /* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */ | |
589 | ||
590 | static inline void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, struct cfq_group *curr_cfqg) { } | |
591 | static inline void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { } | |
592 | static inline void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { } | |
593 | static inline void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) { } | |
594 | static inline void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { } | |
595 | static inline void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) { } | |
596 | static inline void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { } | |
597 | ||
598 | #endif /* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */ | |
599 | ||
600 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
601 | ||
602 | static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd) | |
603 | { | |
604 | return pd ? container_of(pd, struct cfq_group, pd) : NULL; | |
605 | } | |
606 | ||
607 | static struct cfq_group_data | |
608 | *cpd_to_cfqgd(struct blkcg_policy_data *cpd) | |
609 | { | |
610 | return cpd ? container_of(cpd, struct cfq_group_data, cpd) : NULL; | |
611 | } | |
612 | ||
613 | static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg) | |
614 | { | |
615 | return pd_to_blkg(&cfqg->pd); | |
616 | } | |
617 | ||
618 | static struct blkcg_policy blkcg_policy_cfq; | |
619 | ||
620 | static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg) | |
621 | { | |
622 | return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq)); | |
623 | } | |
624 | ||
625 | static struct cfq_group_data *blkcg_to_cfqgd(struct blkcg *blkcg) | |
626 | { | |
627 | return cpd_to_cfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_cfq)); | |
628 | } | |
629 | ||
630 | static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) | |
631 | { | |
632 | struct blkcg_gq *pblkg = cfqg_to_blkg(cfqg)->parent; | |
633 | ||
634 | return pblkg ? blkg_to_cfqg(pblkg) : NULL; | |
635 | } | |
636 | ||
637 | static inline bool cfqg_is_descendant(struct cfq_group *cfqg, | |
638 | struct cfq_group *ancestor) | |
639 | { | |
640 | return cgroup_is_descendant(cfqg_to_blkg(cfqg)->blkcg->css.cgroup, | |
641 | cfqg_to_blkg(ancestor)->blkcg->css.cgroup); | |
642 | } | |
643 | ||
644 | static inline void cfqg_get(struct cfq_group *cfqg) | |
645 | { | |
646 | return blkg_get(cfqg_to_blkg(cfqg)); | |
647 | } | |
648 | ||
649 | static inline void cfqg_put(struct cfq_group *cfqg) | |
650 | { | |
651 | return blkg_put(cfqg_to_blkg(cfqg)); | |
652 | } | |
653 | ||
654 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) do { \ | |
655 | char __pbuf[128]; \ | |
656 | \ | |
657 | blkg_path(cfqg_to_blkg((cfqq)->cfqg), __pbuf, sizeof(__pbuf)); \ | |
658 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c %s " fmt, (cfqq)->pid, \ | |
659 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ | |
660 | cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\ | |
661 | __pbuf, ##args); \ | |
662 | } while (0) | |
663 | ||
664 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do { \ | |
665 | char __pbuf[128]; \ | |
666 | \ | |
667 | blkg_path(cfqg_to_blkg(cfqg), __pbuf, sizeof(__pbuf)); \ | |
668 | blk_add_trace_msg((cfqd)->queue, "%s " fmt, __pbuf, ##args); \ | |
669 | } while (0) | |
670 | ||
671 | static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, | |
672 | struct cfq_group *curr_cfqg, | |
673 | unsigned int op) | |
674 | { | |
675 | blkg_rwstat_add(&cfqg->stats.queued, op, 1); | |
676 | cfqg_stats_end_empty_time(&cfqg->stats); | |
677 | cfqg_stats_set_start_group_wait_time(cfqg, curr_cfqg); | |
678 | } | |
679 | ||
680 | static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, | |
681 | uint64_t time, unsigned long unaccounted_time) | |
682 | { | |
683 | blkg_stat_add(&cfqg->stats.time, time); | |
684 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
685 | blkg_stat_add(&cfqg->stats.unaccounted_time, unaccounted_time); | |
686 | #endif | |
687 | } | |
688 | ||
689 | static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, | |
690 | unsigned int op) | |
691 | { | |
692 | blkg_rwstat_add(&cfqg->stats.queued, op, -1); | |
693 | } | |
694 | ||
695 | static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, | |
696 | unsigned int op) | |
697 | { | |
698 | blkg_rwstat_add(&cfqg->stats.merged, op, 1); | |
699 | } | |
700 | ||
701 | static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, | |
702 | uint64_t start_time, uint64_t io_start_time, | |
703 | unsigned int op) | |
704 | { | |
705 | struct cfqg_stats *stats = &cfqg->stats; | |
706 | unsigned long long now = sched_clock(); | |
707 | ||
708 | if (time_after64(now, io_start_time)) | |
709 | blkg_rwstat_add(&stats->service_time, op, now - io_start_time); | |
710 | if (time_after64(io_start_time, start_time)) | |
711 | blkg_rwstat_add(&stats->wait_time, op, | |
712 | io_start_time - start_time); | |
713 | } | |
714 | ||
715 | /* @stats = 0 */ | |
716 | static void cfqg_stats_reset(struct cfqg_stats *stats) | |
717 | { | |
718 | /* queued stats shouldn't be cleared */ | |
719 | blkg_rwstat_reset(&stats->merged); | |
720 | blkg_rwstat_reset(&stats->service_time); | |
721 | blkg_rwstat_reset(&stats->wait_time); | |
722 | blkg_stat_reset(&stats->time); | |
723 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
724 | blkg_stat_reset(&stats->unaccounted_time); | |
725 | blkg_stat_reset(&stats->avg_queue_size_sum); | |
726 | blkg_stat_reset(&stats->avg_queue_size_samples); | |
727 | blkg_stat_reset(&stats->dequeue); | |
728 | blkg_stat_reset(&stats->group_wait_time); | |
729 | blkg_stat_reset(&stats->idle_time); | |
730 | blkg_stat_reset(&stats->empty_time); | |
731 | #endif | |
732 | } | |
733 | ||
734 | /* @to += @from */ | |
735 | static void cfqg_stats_add_aux(struct cfqg_stats *to, struct cfqg_stats *from) | |
736 | { | |
737 | /* queued stats shouldn't be cleared */ | |
738 | blkg_rwstat_add_aux(&to->merged, &from->merged); | |
739 | blkg_rwstat_add_aux(&to->service_time, &from->service_time); | |
740 | blkg_rwstat_add_aux(&to->wait_time, &from->wait_time); | |
741 | blkg_stat_add_aux(&from->time, &from->time); | |
742 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
743 | blkg_stat_add_aux(&to->unaccounted_time, &from->unaccounted_time); | |
744 | blkg_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum); | |
745 | blkg_stat_add_aux(&to->avg_queue_size_samples, &from->avg_queue_size_samples); | |
746 | blkg_stat_add_aux(&to->dequeue, &from->dequeue); | |
747 | blkg_stat_add_aux(&to->group_wait_time, &from->group_wait_time); | |
748 | blkg_stat_add_aux(&to->idle_time, &from->idle_time); | |
749 | blkg_stat_add_aux(&to->empty_time, &from->empty_time); | |
750 | #endif | |
751 | } | |
752 | ||
753 | /* | |
754 | * Transfer @cfqg's stats to its parent's aux counts so that the ancestors' | |
755 | * recursive stats can still account for the amount used by this cfqg after | |
756 | * it's gone. | |
757 | */ | |
758 | static void cfqg_stats_xfer_dead(struct cfq_group *cfqg) | |
759 | { | |
760 | struct cfq_group *parent = cfqg_parent(cfqg); | |
761 | ||
762 | lockdep_assert_held(cfqg_to_blkg(cfqg)->q->queue_lock); | |
763 | ||
764 | if (unlikely(!parent)) | |
765 | return; | |
766 | ||
767 | cfqg_stats_add_aux(&parent->stats, &cfqg->stats); | |
768 | cfqg_stats_reset(&cfqg->stats); | |
769 | } | |
770 | ||
771 | #else /* CONFIG_CFQ_GROUP_IOSCHED */ | |
772 | ||
773 | static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) { return NULL; } | |
774 | static inline bool cfqg_is_descendant(struct cfq_group *cfqg, | |
775 | struct cfq_group *ancestor) | |
776 | { | |
777 | return true; | |
778 | } | |
779 | static inline void cfqg_get(struct cfq_group *cfqg) { } | |
780 | static inline void cfqg_put(struct cfq_group *cfqg) { } | |
781 | ||
782 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ | |
783 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c " fmt, (cfqq)->pid, \ | |
784 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ | |
785 | cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\ | |
786 | ##args) | |
787 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0) | |
788 | ||
789 | static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, | |
790 | struct cfq_group *curr_cfqg, unsigned int op) { } | |
791 | static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, | |
792 | uint64_t time, unsigned long unaccounted_time) { } | |
793 | static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, | |
794 | unsigned int op) { } | |
795 | static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, | |
796 | unsigned int op) { } | |
797 | static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, | |
798 | uint64_t start_time, uint64_t io_start_time, | |
799 | unsigned int op) { } | |
800 | ||
801 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ | |
802 | ||
803 | #define cfq_log(cfqd, fmt, args...) \ | |
804 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) | |
805 | ||
806 | /* Traverses through cfq group service trees */ | |
807 | #define for_each_cfqg_st(cfqg, i, j, st) \ | |
808 | for (i = 0; i <= IDLE_WORKLOAD; i++) \ | |
809 | for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\ | |
810 | : &cfqg->service_tree_idle; \ | |
811 | (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \ | |
812 | (i == IDLE_WORKLOAD && j == 0); \ | |
813 | j++, st = i < IDLE_WORKLOAD ? \ | |
814 | &cfqg->service_trees[i][j]: NULL) \ | |
815 | ||
816 | static inline bool cfq_io_thinktime_big(struct cfq_data *cfqd, | |
817 | struct cfq_ttime *ttime, bool group_idle) | |
818 | { | |
819 | u64 slice; | |
820 | if (!sample_valid(ttime->ttime_samples)) | |
821 | return false; | |
822 | if (group_idle) | |
823 | slice = cfqd->cfq_group_idle; | |
824 | else | |
825 | slice = cfqd->cfq_slice_idle; | |
826 | return ttime->ttime_mean > slice; | |
827 | } | |
828 | ||
829 | static inline bool iops_mode(struct cfq_data *cfqd) | |
830 | { | |
831 | /* | |
832 | * If we are not idling on queues and it is a NCQ drive, parallel | |
833 | * execution of requests is on and measuring time is not possible | |
834 | * in most of the cases until and unless we drive shallower queue | |
835 | * depths and that becomes a performance bottleneck. In such cases | |
836 | * switch to start providing fairness in terms of number of IOs. | |
837 | */ | |
838 | if (!cfqd->cfq_slice_idle && cfqd->hw_tag) | |
839 | return true; | |
840 | else | |
841 | return false; | |
842 | } | |
843 | ||
844 | static inline enum wl_class_t cfqq_class(struct cfq_queue *cfqq) | |
845 | { | |
846 | if (cfq_class_idle(cfqq)) | |
847 | return IDLE_WORKLOAD; | |
848 | if (cfq_class_rt(cfqq)) | |
849 | return RT_WORKLOAD; | |
850 | return BE_WORKLOAD; | |
851 | } | |
852 | ||
853 | ||
854 | static enum wl_type_t cfqq_type(struct cfq_queue *cfqq) | |
855 | { | |
856 | if (!cfq_cfqq_sync(cfqq)) | |
857 | return ASYNC_WORKLOAD; | |
858 | if (!cfq_cfqq_idle_window(cfqq)) | |
859 | return SYNC_NOIDLE_WORKLOAD; | |
860 | return SYNC_WORKLOAD; | |
861 | } | |
862 | ||
863 | static inline int cfq_group_busy_queues_wl(enum wl_class_t wl_class, | |
864 | struct cfq_data *cfqd, | |
865 | struct cfq_group *cfqg) | |
866 | { | |
867 | if (wl_class == IDLE_WORKLOAD) | |
868 | return cfqg->service_tree_idle.count; | |
869 | ||
870 | return cfqg->service_trees[wl_class][ASYNC_WORKLOAD].count + | |
871 | cfqg->service_trees[wl_class][SYNC_NOIDLE_WORKLOAD].count + | |
872 | cfqg->service_trees[wl_class][SYNC_WORKLOAD].count; | |
873 | } | |
874 | ||
875 | static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, | |
876 | struct cfq_group *cfqg) | |
877 | { | |
878 | return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count + | |
879 | cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count; | |
880 | } | |
881 | ||
882 | static void cfq_dispatch_insert(struct request_queue *, struct request *); | |
883 | static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, bool is_sync, | |
884 | struct cfq_io_cq *cic, struct bio *bio); | |
885 | ||
886 | static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq) | |
887 | { | |
888 | /* cic->icq is the first member, %NULL will convert to %NULL */ | |
889 | return container_of(icq, struct cfq_io_cq, icq); | |
890 | } | |
891 | ||
892 | static inline struct cfq_io_cq *cfq_cic_lookup(struct cfq_data *cfqd, | |
893 | struct io_context *ioc) | |
894 | { | |
895 | if (ioc) | |
896 | return icq_to_cic(ioc_lookup_icq(ioc, cfqd->queue)); | |
897 | return NULL; | |
898 | } | |
899 | ||
900 | static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_cq *cic, bool is_sync) | |
901 | { | |
902 | return cic->cfqq[is_sync]; | |
903 | } | |
904 | ||
905 | static inline void cic_set_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq, | |
906 | bool is_sync) | |
907 | { | |
908 | cic->cfqq[is_sync] = cfqq; | |
909 | } | |
910 | ||
911 | static inline struct cfq_data *cic_to_cfqd(struct cfq_io_cq *cic) | |
912 | { | |
913 | return cic->icq.q->elevator->elevator_data; | |
914 | } | |
915 | ||
916 | /* | |
917 | * scheduler run of queue, if there are requests pending and no one in the | |
918 | * driver that will restart queueing | |
919 | */ | |
920 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) | |
921 | { | |
922 | if (cfqd->busy_queues) { | |
923 | cfq_log(cfqd, "schedule dispatch"); | |
924 | kblockd_schedule_work(&cfqd->unplug_work); | |
925 | } | |
926 | } | |
927 | ||
928 | /* | |
929 | * Scale schedule slice based on io priority. Use the sync time slice only | |
930 | * if a queue is marked sync and has sync io queued. A sync queue with async | |
931 | * io only, should not get full sync slice length. | |
932 | */ | |
933 | static inline u64 cfq_prio_slice(struct cfq_data *cfqd, bool sync, | |
934 | unsigned short prio) | |
935 | { | |
936 | u64 base_slice = cfqd->cfq_slice[sync]; | |
937 | u64 slice = div_u64(base_slice, CFQ_SLICE_SCALE); | |
938 | ||
939 | WARN_ON(prio >= IOPRIO_BE_NR); | |
940 | ||
941 | return base_slice + (slice * (4 - prio)); | |
942 | } | |
943 | ||
944 | static inline u64 | |
945 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
946 | { | |
947 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); | |
948 | } | |
949 | ||
950 | /** | |
951 | * cfqg_scale_charge - scale disk time charge according to cfqg weight | |
952 | * @charge: disk time being charged | |
953 | * @vfraction: vfraction of the cfqg, fixed point w/ CFQ_SERVICE_SHIFT | |
954 | * | |
955 | * Scale @charge according to @vfraction, which is in range (0, 1]. The | |
956 | * scaling is inversely proportional. | |
957 | * | |
958 | * scaled = charge / vfraction | |
959 | * | |
960 | * The result is also in fixed point w/ CFQ_SERVICE_SHIFT. | |
961 | */ | |
962 | static inline u64 cfqg_scale_charge(u64 charge, | |
963 | unsigned int vfraction) | |
964 | { | |
965 | u64 c = charge << CFQ_SERVICE_SHIFT; /* make it fixed point */ | |
966 | ||
967 | /* charge / vfraction */ | |
968 | c <<= CFQ_SERVICE_SHIFT; | |
969 | return div_u64(c, vfraction); | |
970 | } | |
971 | ||
972 | static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime) | |
973 | { | |
974 | s64 delta = (s64)(vdisktime - min_vdisktime); | |
975 | if (delta > 0) | |
976 | min_vdisktime = vdisktime; | |
977 | ||
978 | return min_vdisktime; | |
979 | } | |
980 | ||
981 | static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime) | |
982 | { | |
983 | s64 delta = (s64)(vdisktime - min_vdisktime); | |
984 | if (delta < 0) | |
985 | min_vdisktime = vdisktime; | |
986 | ||
987 | return min_vdisktime; | |
988 | } | |
989 | ||
990 | static void update_min_vdisktime(struct cfq_rb_root *st) | |
991 | { | |
992 | struct cfq_group *cfqg; | |
993 | ||
994 | if (st->left) { | |
995 | cfqg = rb_entry_cfqg(st->left); | |
996 | st->min_vdisktime = max_vdisktime(st->min_vdisktime, | |
997 | cfqg->vdisktime); | |
998 | } | |
999 | } | |
1000 | ||
1001 | /* | |
1002 | * get averaged number of queues of RT/BE priority. | |
1003 | * average is updated, with a formula that gives more weight to higher numbers, | |
1004 | * to quickly follows sudden increases and decrease slowly | |
1005 | */ | |
1006 | ||
1007 | static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd, | |
1008 | struct cfq_group *cfqg, bool rt) | |
1009 | { | |
1010 | unsigned min_q, max_q; | |
1011 | unsigned mult = cfq_hist_divisor - 1; | |
1012 | unsigned round = cfq_hist_divisor / 2; | |
1013 | unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg); | |
1014 | ||
1015 | min_q = min(cfqg->busy_queues_avg[rt], busy); | |
1016 | max_q = max(cfqg->busy_queues_avg[rt], busy); | |
1017 | cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) / | |
1018 | cfq_hist_divisor; | |
1019 | return cfqg->busy_queues_avg[rt]; | |
1020 | } | |
1021 | ||
1022 | static inline u64 | |
1023 | cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
1024 | { | |
1025 | return cfqd->cfq_target_latency * cfqg->vfraction >> CFQ_SERVICE_SHIFT; | |
1026 | } | |
1027 | ||
1028 | static inline u64 | |
1029 | cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
1030 | { | |
1031 | u64 slice = cfq_prio_to_slice(cfqd, cfqq); | |
1032 | if (cfqd->cfq_latency) { | |
1033 | /* | |
1034 | * interested queues (we consider only the ones with the same | |
1035 | * priority class in the cfq group) | |
1036 | */ | |
1037 | unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg, | |
1038 | cfq_class_rt(cfqq)); | |
1039 | u64 sync_slice = cfqd->cfq_slice[1]; | |
1040 | u64 expect_latency = sync_slice * iq; | |
1041 | u64 group_slice = cfq_group_slice(cfqd, cfqq->cfqg); | |
1042 | ||
1043 | if (expect_latency > group_slice) { | |
1044 | u64 base_low_slice = 2 * cfqd->cfq_slice_idle; | |
1045 | u64 low_slice; | |
1046 | ||
1047 | /* scale low_slice according to IO priority | |
1048 | * and sync vs async */ | |
1049 | low_slice = div64_u64(base_low_slice*slice, sync_slice); | |
1050 | low_slice = min(slice, low_slice); | |
1051 | /* the adapted slice value is scaled to fit all iqs | |
1052 | * into the target latency */ | |
1053 | slice = div64_u64(slice*group_slice, expect_latency); | |
1054 | slice = max(slice, low_slice); | |
1055 | } | |
1056 | } | |
1057 | return slice; | |
1058 | } | |
1059 | ||
1060 | static inline void | |
1061 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
1062 | { | |
1063 | u64 slice = cfq_scaled_cfqq_slice(cfqd, cfqq); | |
1064 | u64 now = ktime_get_ns(); | |
1065 | ||
1066 | cfqq->slice_start = now; | |
1067 | cfqq->slice_end = now + slice; | |
1068 | cfqq->allocated_slice = slice; | |
1069 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%llu", cfqq->slice_end - now); | |
1070 | } | |
1071 | ||
1072 | /* | |
1073 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end | |
1074 | * isn't valid until the first request from the dispatch is activated | |
1075 | * and the slice time set. | |
1076 | */ | |
1077 | static inline bool cfq_slice_used(struct cfq_queue *cfqq) | |
1078 | { | |
1079 | if (cfq_cfqq_slice_new(cfqq)) | |
1080 | return false; | |
1081 | if (ktime_get_ns() < cfqq->slice_end) | |
1082 | return false; | |
1083 | ||
1084 | return true; | |
1085 | } | |
1086 | ||
1087 | /* | |
1088 | * Lifted from AS - choose which of rq1 and rq2 that is best served now. | |
1089 | * We choose the request that is closest to the head right now. Distance | |
1090 | * behind the head is penalized and only allowed to a certain extent. | |
1091 | */ | |
1092 | static struct request * | |
1093 | cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, sector_t last) | |
1094 | { | |
1095 | sector_t s1, s2, d1 = 0, d2 = 0; | |
1096 | unsigned long back_max; | |
1097 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ | |
1098 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ | |
1099 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ | |
1100 | ||
1101 | if (rq1 == NULL || rq1 == rq2) | |
1102 | return rq2; | |
1103 | if (rq2 == NULL) | |
1104 | return rq1; | |
1105 | ||
1106 | if (rq_is_sync(rq1) != rq_is_sync(rq2)) | |
1107 | return rq_is_sync(rq1) ? rq1 : rq2; | |
1108 | ||
1109 | if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_PRIO) | |
1110 | return rq1->cmd_flags & REQ_PRIO ? rq1 : rq2; | |
1111 | ||
1112 | s1 = blk_rq_pos(rq1); | |
1113 | s2 = blk_rq_pos(rq2); | |
1114 | ||
1115 | /* | |
1116 | * by definition, 1KiB is 2 sectors | |
1117 | */ | |
1118 | back_max = cfqd->cfq_back_max * 2; | |
1119 | ||
1120 | /* | |
1121 | * Strict one way elevator _except_ in the case where we allow | |
1122 | * short backward seeks which are biased as twice the cost of a | |
1123 | * similar forward seek. | |
1124 | */ | |
1125 | if (s1 >= last) | |
1126 | d1 = s1 - last; | |
1127 | else if (s1 + back_max >= last) | |
1128 | d1 = (last - s1) * cfqd->cfq_back_penalty; | |
1129 | else | |
1130 | wrap |= CFQ_RQ1_WRAP; | |
1131 | ||
1132 | if (s2 >= last) | |
1133 | d2 = s2 - last; | |
1134 | else if (s2 + back_max >= last) | |
1135 | d2 = (last - s2) * cfqd->cfq_back_penalty; | |
1136 | else | |
1137 | wrap |= CFQ_RQ2_WRAP; | |
1138 | ||
1139 | /* Found required data */ | |
1140 | ||
1141 | /* | |
1142 | * By doing switch() on the bit mask "wrap" we avoid having to | |
1143 | * check two variables for all permutations: --> faster! | |
1144 | */ | |
1145 | switch (wrap) { | |
1146 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ | |
1147 | if (d1 < d2) | |
1148 | return rq1; | |
1149 | else if (d2 < d1) | |
1150 | return rq2; | |
1151 | else { | |
1152 | if (s1 >= s2) | |
1153 | return rq1; | |
1154 | else | |
1155 | return rq2; | |
1156 | } | |
1157 | ||
1158 | case CFQ_RQ2_WRAP: | |
1159 | return rq1; | |
1160 | case CFQ_RQ1_WRAP: | |
1161 | return rq2; | |
1162 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ | |
1163 | default: | |
1164 | /* | |
1165 | * Since both rqs are wrapped, | |
1166 | * start with the one that's further behind head | |
1167 | * (--> only *one* back seek required), | |
1168 | * since back seek takes more time than forward. | |
1169 | */ | |
1170 | if (s1 <= s2) | |
1171 | return rq1; | |
1172 | else | |
1173 | return rq2; | |
1174 | } | |
1175 | } | |
1176 | ||
1177 | /* | |
1178 | * The below is leftmost cache rbtree addon | |
1179 | */ | |
1180 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) | |
1181 | { | |
1182 | /* Service tree is empty */ | |
1183 | if (!root->count) | |
1184 | return NULL; | |
1185 | ||
1186 | if (!root->left) | |
1187 | root->left = rb_first(&root->rb); | |
1188 | ||
1189 | if (root->left) | |
1190 | return rb_entry(root->left, struct cfq_queue, rb_node); | |
1191 | ||
1192 | return NULL; | |
1193 | } | |
1194 | ||
1195 | static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root) | |
1196 | { | |
1197 | if (!root->left) | |
1198 | root->left = rb_first(&root->rb); | |
1199 | ||
1200 | if (root->left) | |
1201 | return rb_entry_cfqg(root->left); | |
1202 | ||
1203 | return NULL; | |
1204 | } | |
1205 | ||
1206 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) | |
1207 | { | |
1208 | rb_erase(n, root); | |
1209 | RB_CLEAR_NODE(n); | |
1210 | } | |
1211 | ||
1212 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) | |
1213 | { | |
1214 | if (root->left == n) | |
1215 | root->left = NULL; | |
1216 | rb_erase_init(n, &root->rb); | |
1217 | --root->count; | |
1218 | } | |
1219 | ||
1220 | /* | |
1221 | * would be nice to take fifo expire time into account as well | |
1222 | */ | |
1223 | static struct request * | |
1224 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
1225 | struct request *last) | |
1226 | { | |
1227 | struct rb_node *rbnext = rb_next(&last->rb_node); | |
1228 | struct rb_node *rbprev = rb_prev(&last->rb_node); | |
1229 | struct request *next = NULL, *prev = NULL; | |
1230 | ||
1231 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); | |
1232 | ||
1233 | if (rbprev) | |
1234 | prev = rb_entry_rq(rbprev); | |
1235 | ||
1236 | if (rbnext) | |
1237 | next = rb_entry_rq(rbnext); | |
1238 | else { | |
1239 | rbnext = rb_first(&cfqq->sort_list); | |
1240 | if (rbnext && rbnext != &last->rb_node) | |
1241 | next = rb_entry_rq(rbnext); | |
1242 | } | |
1243 | ||
1244 | return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); | |
1245 | } | |
1246 | ||
1247 | static u64 cfq_slice_offset(struct cfq_data *cfqd, | |
1248 | struct cfq_queue *cfqq) | |
1249 | { | |
1250 | /* | |
1251 | * just an approximation, should be ok. | |
1252 | */ | |
1253 | return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - | |
1254 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); | |
1255 | } | |
1256 | ||
1257 | static inline s64 | |
1258 | cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1259 | { | |
1260 | return cfqg->vdisktime - st->min_vdisktime; | |
1261 | } | |
1262 | ||
1263 | static void | |
1264 | __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1265 | { | |
1266 | struct rb_node **node = &st->rb.rb_node; | |
1267 | struct rb_node *parent = NULL; | |
1268 | struct cfq_group *__cfqg; | |
1269 | s64 key = cfqg_key(st, cfqg); | |
1270 | int left = 1; | |
1271 | ||
1272 | while (*node != NULL) { | |
1273 | parent = *node; | |
1274 | __cfqg = rb_entry_cfqg(parent); | |
1275 | ||
1276 | if (key < cfqg_key(st, __cfqg)) | |
1277 | node = &parent->rb_left; | |
1278 | else { | |
1279 | node = &parent->rb_right; | |
1280 | left = 0; | |
1281 | } | |
1282 | } | |
1283 | ||
1284 | if (left) | |
1285 | st->left = &cfqg->rb_node; | |
1286 | ||
1287 | rb_link_node(&cfqg->rb_node, parent, node); | |
1288 | rb_insert_color(&cfqg->rb_node, &st->rb); | |
1289 | } | |
1290 | ||
1291 | /* | |
1292 | * This has to be called only on activation of cfqg | |
1293 | */ | |
1294 | static void | |
1295 | cfq_update_group_weight(struct cfq_group *cfqg) | |
1296 | { | |
1297 | if (cfqg->new_weight) { | |
1298 | cfqg->weight = cfqg->new_weight; | |
1299 | cfqg->new_weight = 0; | |
1300 | } | |
1301 | } | |
1302 | ||
1303 | static void | |
1304 | cfq_update_group_leaf_weight(struct cfq_group *cfqg) | |
1305 | { | |
1306 | BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node)); | |
1307 | ||
1308 | if (cfqg->new_leaf_weight) { | |
1309 | cfqg->leaf_weight = cfqg->new_leaf_weight; | |
1310 | cfqg->new_leaf_weight = 0; | |
1311 | } | |
1312 | } | |
1313 | ||
1314 | static void | |
1315 | cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1316 | { | |
1317 | unsigned int vfr = 1 << CFQ_SERVICE_SHIFT; /* start with 1 */ | |
1318 | struct cfq_group *pos = cfqg; | |
1319 | struct cfq_group *parent; | |
1320 | bool propagate; | |
1321 | ||
1322 | /* add to the service tree */ | |
1323 | BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node)); | |
1324 | ||
1325 | /* | |
1326 | * Update leaf_weight. We cannot update weight at this point | |
1327 | * because cfqg might already have been activated and is | |
1328 | * contributing its current weight to the parent's child_weight. | |
1329 | */ | |
1330 | cfq_update_group_leaf_weight(cfqg); | |
1331 | __cfq_group_service_tree_add(st, cfqg); | |
1332 | ||
1333 | /* | |
1334 | * Activate @cfqg and calculate the portion of vfraction @cfqg is | |
1335 | * entitled to. vfraction is calculated by walking the tree | |
1336 | * towards the root calculating the fraction it has at each level. | |
1337 | * The compounded ratio is how much vfraction @cfqg owns. | |
1338 | * | |
1339 | * Start with the proportion tasks in this cfqg has against active | |
1340 | * children cfqgs - its leaf_weight against children_weight. | |
1341 | */ | |
1342 | propagate = !pos->nr_active++; | |
1343 | pos->children_weight += pos->leaf_weight; | |
1344 | vfr = vfr * pos->leaf_weight / pos->children_weight; | |
1345 | ||
1346 | /* | |
1347 | * Compound ->weight walking up the tree. Both activation and | |
1348 | * vfraction calculation are done in the same loop. Propagation | |
1349 | * stops once an already activated node is met. vfraction | |
1350 | * calculation should always continue to the root. | |
1351 | */ | |
1352 | while ((parent = cfqg_parent(pos))) { | |
1353 | if (propagate) { | |
1354 | cfq_update_group_weight(pos); | |
1355 | propagate = !parent->nr_active++; | |
1356 | parent->children_weight += pos->weight; | |
1357 | } | |
1358 | vfr = vfr * pos->weight / parent->children_weight; | |
1359 | pos = parent; | |
1360 | } | |
1361 | ||
1362 | cfqg->vfraction = max_t(unsigned, vfr, 1); | |
1363 | } | |
1364 | ||
1365 | static void | |
1366 | cfq_group_notify_queue_add(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
1367 | { | |
1368 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
1369 | struct cfq_group *__cfqg; | |
1370 | struct rb_node *n; | |
1371 | ||
1372 | cfqg->nr_cfqq++; | |
1373 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) | |
1374 | return; | |
1375 | ||
1376 | /* | |
1377 | * Currently put the group at the end. Later implement something | |
1378 | * so that groups get lesser vtime based on their weights, so that | |
1379 | * if group does not loose all if it was not continuously backlogged. | |
1380 | */ | |
1381 | n = rb_last(&st->rb); | |
1382 | if (n) { | |
1383 | __cfqg = rb_entry_cfqg(n); | |
1384 | cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY; | |
1385 | } else | |
1386 | cfqg->vdisktime = st->min_vdisktime; | |
1387 | cfq_group_service_tree_add(st, cfqg); | |
1388 | } | |
1389 | ||
1390 | static void | |
1391 | cfq_group_service_tree_del(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1392 | { | |
1393 | struct cfq_group *pos = cfqg; | |
1394 | bool propagate; | |
1395 | ||
1396 | /* | |
1397 | * Undo activation from cfq_group_service_tree_add(). Deactivate | |
1398 | * @cfqg and propagate deactivation upwards. | |
1399 | */ | |
1400 | propagate = !--pos->nr_active; | |
1401 | pos->children_weight -= pos->leaf_weight; | |
1402 | ||
1403 | while (propagate) { | |
1404 | struct cfq_group *parent = cfqg_parent(pos); | |
1405 | ||
1406 | /* @pos has 0 nr_active at this point */ | |
1407 | WARN_ON_ONCE(pos->children_weight); | |
1408 | pos->vfraction = 0; | |
1409 | ||
1410 | if (!parent) | |
1411 | break; | |
1412 | ||
1413 | propagate = !--parent->nr_active; | |
1414 | parent->children_weight -= pos->weight; | |
1415 | pos = parent; | |
1416 | } | |
1417 | ||
1418 | /* remove from the service tree */ | |
1419 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) | |
1420 | cfq_rb_erase(&cfqg->rb_node, st); | |
1421 | } | |
1422 | ||
1423 | static void | |
1424 | cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
1425 | { | |
1426 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
1427 | ||
1428 | BUG_ON(cfqg->nr_cfqq < 1); | |
1429 | cfqg->nr_cfqq--; | |
1430 | ||
1431 | /* If there are other cfq queues under this group, don't delete it */ | |
1432 | if (cfqg->nr_cfqq) | |
1433 | return; | |
1434 | ||
1435 | cfq_log_cfqg(cfqd, cfqg, "del_from_rr group"); | |
1436 | cfq_group_service_tree_del(st, cfqg); | |
1437 | cfqg->saved_wl_slice = 0; | |
1438 | cfqg_stats_update_dequeue(cfqg); | |
1439 | } | |
1440 | ||
1441 | static inline u64 cfq_cfqq_slice_usage(struct cfq_queue *cfqq, | |
1442 | u64 *unaccounted_time) | |
1443 | { | |
1444 | u64 slice_used; | |
1445 | u64 now = ktime_get_ns(); | |
1446 | ||
1447 | /* | |
1448 | * Queue got expired before even a single request completed or | |
1449 | * got expired immediately after first request completion. | |
1450 | */ | |
1451 | if (!cfqq->slice_start || cfqq->slice_start == now) { | |
1452 | /* | |
1453 | * Also charge the seek time incurred to the group, otherwise | |
1454 | * if there are mutiple queues in the group, each can dispatch | |
1455 | * a single request on seeky media and cause lots of seek time | |
1456 | * and group will never know it. | |
1457 | */ | |
1458 | slice_used = max_t(u64, (now - cfqq->dispatch_start), | |
1459 | jiffies_to_nsecs(1)); | |
1460 | } else { | |
1461 | slice_used = now - cfqq->slice_start; | |
1462 | if (slice_used > cfqq->allocated_slice) { | |
1463 | *unaccounted_time = slice_used - cfqq->allocated_slice; | |
1464 | slice_used = cfqq->allocated_slice; | |
1465 | } | |
1466 | if (cfqq->slice_start > cfqq->dispatch_start) | |
1467 | *unaccounted_time += cfqq->slice_start - | |
1468 | cfqq->dispatch_start; | |
1469 | } | |
1470 | ||
1471 | return slice_used; | |
1472 | } | |
1473 | ||
1474 | static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, | |
1475 | struct cfq_queue *cfqq) | |
1476 | { | |
1477 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
1478 | u64 used_sl, charge, unaccounted_sl = 0; | |
1479 | int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) | |
1480 | - cfqg->service_tree_idle.count; | |
1481 | unsigned int vfr; | |
1482 | u64 now = ktime_get_ns(); | |
1483 | ||
1484 | BUG_ON(nr_sync < 0); | |
1485 | used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl); | |
1486 | ||
1487 | if (iops_mode(cfqd)) | |
1488 | charge = cfqq->slice_dispatch; | |
1489 | else if (!cfq_cfqq_sync(cfqq) && !nr_sync) | |
1490 | charge = cfqq->allocated_slice; | |
1491 | ||
1492 | /* | |
1493 | * Can't update vdisktime while on service tree and cfqg->vfraction | |
1494 | * is valid only while on it. Cache vfr, leave the service tree, | |
1495 | * update vdisktime and go back on. The re-addition to the tree | |
1496 | * will also update the weights as necessary. | |
1497 | */ | |
1498 | vfr = cfqg->vfraction; | |
1499 | cfq_group_service_tree_del(st, cfqg); | |
1500 | cfqg->vdisktime += cfqg_scale_charge(charge, vfr); | |
1501 | cfq_group_service_tree_add(st, cfqg); | |
1502 | ||
1503 | /* This group is being expired. Save the context */ | |
1504 | if (cfqd->workload_expires > now) { | |
1505 | cfqg->saved_wl_slice = cfqd->workload_expires - now; | |
1506 | cfqg->saved_wl_type = cfqd->serving_wl_type; | |
1507 | cfqg->saved_wl_class = cfqd->serving_wl_class; | |
1508 | } else | |
1509 | cfqg->saved_wl_slice = 0; | |
1510 | ||
1511 | cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime, | |
1512 | st->min_vdisktime); | |
1513 | cfq_log_cfqq(cfqq->cfqd, cfqq, | |
1514 | "sl_used=%llu disp=%llu charge=%llu iops=%u sect=%lu", | |
1515 | used_sl, cfqq->slice_dispatch, charge, | |
1516 | iops_mode(cfqd), cfqq->nr_sectors); | |
1517 | cfqg_stats_update_timeslice_used(cfqg, used_sl, unaccounted_sl); | |
1518 | cfqg_stats_set_start_empty_time(cfqg); | |
1519 | } | |
1520 | ||
1521 | /** | |
1522 | * cfq_init_cfqg_base - initialize base part of a cfq_group | |
1523 | * @cfqg: cfq_group to initialize | |
1524 | * | |
1525 | * Initialize the base part which is used whether %CONFIG_CFQ_GROUP_IOSCHED | |
1526 | * is enabled or not. | |
1527 | */ | |
1528 | static void cfq_init_cfqg_base(struct cfq_group *cfqg) | |
1529 | { | |
1530 | struct cfq_rb_root *st; | |
1531 | int i, j; | |
1532 | ||
1533 | for_each_cfqg_st(cfqg, i, j, st) | |
1534 | *st = CFQ_RB_ROOT; | |
1535 | RB_CLEAR_NODE(&cfqg->rb_node); | |
1536 | ||
1537 | cfqg->ttime.last_end_request = ktime_get_ns(); | |
1538 | } | |
1539 | ||
1540 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
1541 | static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val, | |
1542 | bool on_dfl, bool reset_dev, bool is_leaf_weight); | |
1543 | ||
1544 | static void cfqg_stats_exit(struct cfqg_stats *stats) | |
1545 | { | |
1546 | blkg_rwstat_exit(&stats->merged); | |
1547 | blkg_rwstat_exit(&stats->service_time); | |
1548 | blkg_rwstat_exit(&stats->wait_time); | |
1549 | blkg_rwstat_exit(&stats->queued); | |
1550 | blkg_stat_exit(&stats->time); | |
1551 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
1552 | blkg_stat_exit(&stats->unaccounted_time); | |
1553 | blkg_stat_exit(&stats->avg_queue_size_sum); | |
1554 | blkg_stat_exit(&stats->avg_queue_size_samples); | |
1555 | blkg_stat_exit(&stats->dequeue); | |
1556 | blkg_stat_exit(&stats->group_wait_time); | |
1557 | blkg_stat_exit(&stats->idle_time); | |
1558 | blkg_stat_exit(&stats->empty_time); | |
1559 | #endif | |
1560 | } | |
1561 | ||
1562 | static int cfqg_stats_init(struct cfqg_stats *stats, gfp_t gfp) | |
1563 | { | |
1564 | if (blkg_rwstat_init(&stats->merged, gfp) || | |
1565 | blkg_rwstat_init(&stats->service_time, gfp) || | |
1566 | blkg_rwstat_init(&stats->wait_time, gfp) || | |
1567 | blkg_rwstat_init(&stats->queued, gfp) || | |
1568 | blkg_stat_init(&stats->time, gfp)) | |
1569 | goto err; | |
1570 | ||
1571 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
1572 | if (blkg_stat_init(&stats->unaccounted_time, gfp) || | |
1573 | blkg_stat_init(&stats->avg_queue_size_sum, gfp) || | |
1574 | blkg_stat_init(&stats->avg_queue_size_samples, gfp) || | |
1575 | blkg_stat_init(&stats->dequeue, gfp) || | |
1576 | blkg_stat_init(&stats->group_wait_time, gfp) || | |
1577 | blkg_stat_init(&stats->idle_time, gfp) || | |
1578 | blkg_stat_init(&stats->empty_time, gfp)) | |
1579 | goto err; | |
1580 | #endif | |
1581 | return 0; | |
1582 | err: | |
1583 | cfqg_stats_exit(stats); | |
1584 | return -ENOMEM; | |
1585 | } | |
1586 | ||
1587 | static struct blkcg_policy_data *cfq_cpd_alloc(gfp_t gfp) | |
1588 | { | |
1589 | struct cfq_group_data *cgd; | |
1590 | ||
1591 | cgd = kzalloc(sizeof(*cgd), gfp); | |
1592 | if (!cgd) | |
1593 | return NULL; | |
1594 | return &cgd->cpd; | |
1595 | } | |
1596 | ||
1597 | static void cfq_cpd_init(struct blkcg_policy_data *cpd) | |
1598 | { | |
1599 | struct cfq_group_data *cgd = cpd_to_cfqgd(cpd); | |
1600 | unsigned int weight = cgroup_subsys_on_dfl(io_cgrp_subsys) ? | |
1601 | CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL; | |
1602 | ||
1603 | if (cpd_to_blkcg(cpd) == &blkcg_root) | |
1604 | weight *= 2; | |
1605 | ||
1606 | cgd->weight = weight; | |
1607 | cgd->leaf_weight = weight; | |
1608 | } | |
1609 | ||
1610 | static void cfq_cpd_free(struct blkcg_policy_data *cpd) | |
1611 | { | |
1612 | kfree(cpd_to_cfqgd(cpd)); | |
1613 | } | |
1614 | ||
1615 | static void cfq_cpd_bind(struct blkcg_policy_data *cpd) | |
1616 | { | |
1617 | struct blkcg *blkcg = cpd_to_blkcg(cpd); | |
1618 | bool on_dfl = cgroup_subsys_on_dfl(io_cgrp_subsys); | |
1619 | unsigned int weight = on_dfl ? CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL; | |
1620 | ||
1621 | if (blkcg == &blkcg_root) | |
1622 | weight *= 2; | |
1623 | ||
1624 | WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, false)); | |
1625 | WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, true)); | |
1626 | } | |
1627 | ||
1628 | static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node) | |
1629 | { | |
1630 | struct cfq_group *cfqg; | |
1631 | ||
1632 | cfqg = kzalloc_node(sizeof(*cfqg), gfp, node); | |
1633 | if (!cfqg) | |
1634 | return NULL; | |
1635 | ||
1636 | cfq_init_cfqg_base(cfqg); | |
1637 | if (cfqg_stats_init(&cfqg->stats, gfp)) { | |
1638 | kfree(cfqg); | |
1639 | return NULL; | |
1640 | } | |
1641 | ||
1642 | return &cfqg->pd; | |
1643 | } | |
1644 | ||
1645 | static void cfq_pd_init(struct blkg_policy_data *pd) | |
1646 | { | |
1647 | struct cfq_group *cfqg = pd_to_cfqg(pd); | |
1648 | struct cfq_group_data *cgd = blkcg_to_cfqgd(pd->blkg->blkcg); | |
1649 | ||
1650 | cfqg->weight = cgd->weight; | |
1651 | cfqg->leaf_weight = cgd->leaf_weight; | |
1652 | } | |
1653 | ||
1654 | static void cfq_pd_offline(struct blkg_policy_data *pd) | |
1655 | { | |
1656 | struct cfq_group *cfqg = pd_to_cfqg(pd); | |
1657 | int i; | |
1658 | ||
1659 | for (i = 0; i < IOPRIO_BE_NR; i++) { | |
1660 | if (cfqg->async_cfqq[0][i]) | |
1661 | cfq_put_queue(cfqg->async_cfqq[0][i]); | |
1662 | if (cfqg->async_cfqq[1][i]) | |
1663 | cfq_put_queue(cfqg->async_cfqq[1][i]); | |
1664 | } | |
1665 | ||
1666 | if (cfqg->async_idle_cfqq) | |
1667 | cfq_put_queue(cfqg->async_idle_cfqq); | |
1668 | ||
1669 | /* | |
1670 | * @blkg is going offline and will be ignored by | |
1671 | * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so | |
1672 | * that they don't get lost. If IOs complete after this point, the | |
1673 | * stats for them will be lost. Oh well... | |
1674 | */ | |
1675 | cfqg_stats_xfer_dead(cfqg); | |
1676 | } | |
1677 | ||
1678 | static void cfq_pd_free(struct blkg_policy_data *pd) | |
1679 | { | |
1680 | struct cfq_group *cfqg = pd_to_cfqg(pd); | |
1681 | ||
1682 | cfqg_stats_exit(&cfqg->stats); | |
1683 | return kfree(cfqg); | |
1684 | } | |
1685 | ||
1686 | static void cfq_pd_reset_stats(struct blkg_policy_data *pd) | |
1687 | { | |
1688 | struct cfq_group *cfqg = pd_to_cfqg(pd); | |
1689 | ||
1690 | cfqg_stats_reset(&cfqg->stats); | |
1691 | } | |
1692 | ||
1693 | static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd, | |
1694 | struct blkcg *blkcg) | |
1695 | { | |
1696 | struct blkcg_gq *blkg; | |
1697 | ||
1698 | blkg = blkg_lookup(blkcg, cfqd->queue); | |
1699 | if (likely(blkg)) | |
1700 | return blkg_to_cfqg(blkg); | |
1701 | return NULL; | |
1702 | } | |
1703 | ||
1704 | static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) | |
1705 | { | |
1706 | cfqq->cfqg = cfqg; | |
1707 | /* cfqq reference on cfqg */ | |
1708 | cfqg_get(cfqg); | |
1709 | } | |
1710 | ||
1711 | static u64 cfqg_prfill_weight_device(struct seq_file *sf, | |
1712 | struct blkg_policy_data *pd, int off) | |
1713 | { | |
1714 | struct cfq_group *cfqg = pd_to_cfqg(pd); | |
1715 | ||
1716 | if (!cfqg->dev_weight) | |
1717 | return 0; | |
1718 | return __blkg_prfill_u64(sf, pd, cfqg->dev_weight); | |
1719 | } | |
1720 | ||
1721 | static int cfqg_print_weight_device(struct seq_file *sf, void *v) | |
1722 | { | |
1723 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1724 | cfqg_prfill_weight_device, &blkcg_policy_cfq, | |
1725 | 0, false); | |
1726 | return 0; | |
1727 | } | |
1728 | ||
1729 | static u64 cfqg_prfill_leaf_weight_device(struct seq_file *sf, | |
1730 | struct blkg_policy_data *pd, int off) | |
1731 | { | |
1732 | struct cfq_group *cfqg = pd_to_cfqg(pd); | |
1733 | ||
1734 | if (!cfqg->dev_leaf_weight) | |
1735 | return 0; | |
1736 | return __blkg_prfill_u64(sf, pd, cfqg->dev_leaf_weight); | |
1737 | } | |
1738 | ||
1739 | static int cfqg_print_leaf_weight_device(struct seq_file *sf, void *v) | |
1740 | { | |
1741 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1742 | cfqg_prfill_leaf_weight_device, &blkcg_policy_cfq, | |
1743 | 0, false); | |
1744 | return 0; | |
1745 | } | |
1746 | ||
1747 | static int cfq_print_weight(struct seq_file *sf, void *v) | |
1748 | { | |
1749 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); | |
1750 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg); | |
1751 | unsigned int val = 0; | |
1752 | ||
1753 | if (cgd) | |
1754 | val = cgd->weight; | |
1755 | ||
1756 | seq_printf(sf, "%u\n", val); | |
1757 | return 0; | |
1758 | } | |
1759 | ||
1760 | static int cfq_print_leaf_weight(struct seq_file *sf, void *v) | |
1761 | { | |
1762 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); | |
1763 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg); | |
1764 | unsigned int val = 0; | |
1765 | ||
1766 | if (cgd) | |
1767 | val = cgd->leaf_weight; | |
1768 | ||
1769 | seq_printf(sf, "%u\n", val); | |
1770 | return 0; | |
1771 | } | |
1772 | ||
1773 | static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of, | |
1774 | char *buf, size_t nbytes, loff_t off, | |
1775 | bool on_dfl, bool is_leaf_weight) | |
1776 | { | |
1777 | unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN; | |
1778 | unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX; | |
1779 | struct blkcg *blkcg = css_to_blkcg(of_css(of)); | |
1780 | struct blkg_conf_ctx ctx; | |
1781 | struct cfq_group *cfqg; | |
1782 | struct cfq_group_data *cfqgd; | |
1783 | int ret; | |
1784 | u64 v; | |
1785 | ||
1786 | ret = blkg_conf_prep(blkcg, &blkcg_policy_cfq, buf, &ctx); | |
1787 | if (ret) | |
1788 | return ret; | |
1789 | ||
1790 | if (sscanf(ctx.body, "%llu", &v) == 1) { | |
1791 | /* require "default" on dfl */ | |
1792 | ret = -ERANGE; | |
1793 | if (!v && on_dfl) | |
1794 | goto out_finish; | |
1795 | } else if (!strcmp(strim(ctx.body), "default")) { | |
1796 | v = 0; | |
1797 | } else { | |
1798 | ret = -EINVAL; | |
1799 | goto out_finish; | |
1800 | } | |
1801 | ||
1802 | cfqg = blkg_to_cfqg(ctx.blkg); | |
1803 | cfqgd = blkcg_to_cfqgd(blkcg); | |
1804 | ||
1805 | ret = -ERANGE; | |
1806 | if (!v || (v >= min && v <= max)) { | |
1807 | if (!is_leaf_weight) { | |
1808 | cfqg->dev_weight = v; | |
1809 | cfqg->new_weight = v ?: cfqgd->weight; | |
1810 | } else { | |
1811 | cfqg->dev_leaf_weight = v; | |
1812 | cfqg->new_leaf_weight = v ?: cfqgd->leaf_weight; | |
1813 | } | |
1814 | ret = 0; | |
1815 | } | |
1816 | out_finish: | |
1817 | blkg_conf_finish(&ctx); | |
1818 | return ret ?: nbytes; | |
1819 | } | |
1820 | ||
1821 | static ssize_t cfqg_set_weight_device(struct kernfs_open_file *of, | |
1822 | char *buf, size_t nbytes, loff_t off) | |
1823 | { | |
1824 | return __cfqg_set_weight_device(of, buf, nbytes, off, false, false); | |
1825 | } | |
1826 | ||
1827 | static ssize_t cfqg_set_leaf_weight_device(struct kernfs_open_file *of, | |
1828 | char *buf, size_t nbytes, loff_t off) | |
1829 | { | |
1830 | return __cfqg_set_weight_device(of, buf, nbytes, off, false, true); | |
1831 | } | |
1832 | ||
1833 | static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val, | |
1834 | bool on_dfl, bool reset_dev, bool is_leaf_weight) | |
1835 | { | |
1836 | unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN; | |
1837 | unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX; | |
1838 | struct blkcg *blkcg = css_to_blkcg(css); | |
1839 | struct blkcg_gq *blkg; | |
1840 | struct cfq_group_data *cfqgd; | |
1841 | int ret = 0; | |
1842 | ||
1843 | if (val < min || val > max) | |
1844 | return -ERANGE; | |
1845 | ||
1846 | spin_lock_irq(&blkcg->lock); | |
1847 | cfqgd = blkcg_to_cfqgd(blkcg); | |
1848 | if (!cfqgd) { | |
1849 | ret = -EINVAL; | |
1850 | goto out; | |
1851 | } | |
1852 | ||
1853 | if (!is_leaf_weight) | |
1854 | cfqgd->weight = val; | |
1855 | else | |
1856 | cfqgd->leaf_weight = val; | |
1857 | ||
1858 | hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { | |
1859 | struct cfq_group *cfqg = blkg_to_cfqg(blkg); | |
1860 | ||
1861 | if (!cfqg) | |
1862 | continue; | |
1863 | ||
1864 | if (!is_leaf_weight) { | |
1865 | if (reset_dev) | |
1866 | cfqg->dev_weight = 0; | |
1867 | if (!cfqg->dev_weight) | |
1868 | cfqg->new_weight = cfqgd->weight; | |
1869 | } else { | |
1870 | if (reset_dev) | |
1871 | cfqg->dev_leaf_weight = 0; | |
1872 | if (!cfqg->dev_leaf_weight) | |
1873 | cfqg->new_leaf_weight = cfqgd->leaf_weight; | |
1874 | } | |
1875 | } | |
1876 | ||
1877 | out: | |
1878 | spin_unlock_irq(&blkcg->lock); | |
1879 | return ret; | |
1880 | } | |
1881 | ||
1882 | static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft, | |
1883 | u64 val) | |
1884 | { | |
1885 | return __cfq_set_weight(css, val, false, false, false); | |
1886 | } | |
1887 | ||
1888 | static int cfq_set_leaf_weight(struct cgroup_subsys_state *css, | |
1889 | struct cftype *cft, u64 val) | |
1890 | { | |
1891 | return __cfq_set_weight(css, val, false, false, true); | |
1892 | } | |
1893 | ||
1894 | static int cfqg_print_stat(struct seq_file *sf, void *v) | |
1895 | { | |
1896 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat, | |
1897 | &blkcg_policy_cfq, seq_cft(sf)->private, false); | |
1898 | return 0; | |
1899 | } | |
1900 | ||
1901 | static int cfqg_print_rwstat(struct seq_file *sf, void *v) | |
1902 | { | |
1903 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat, | |
1904 | &blkcg_policy_cfq, seq_cft(sf)->private, true); | |
1905 | return 0; | |
1906 | } | |
1907 | ||
1908 | static u64 cfqg_prfill_stat_recursive(struct seq_file *sf, | |
1909 | struct blkg_policy_data *pd, int off) | |
1910 | { | |
1911 | u64 sum = blkg_stat_recursive_sum(pd_to_blkg(pd), | |
1912 | &blkcg_policy_cfq, off); | |
1913 | return __blkg_prfill_u64(sf, pd, sum); | |
1914 | } | |
1915 | ||
1916 | static u64 cfqg_prfill_rwstat_recursive(struct seq_file *sf, | |
1917 | struct blkg_policy_data *pd, int off) | |
1918 | { | |
1919 | struct blkg_rwstat sum = blkg_rwstat_recursive_sum(pd_to_blkg(pd), | |
1920 | &blkcg_policy_cfq, off); | |
1921 | return __blkg_prfill_rwstat(sf, pd, &sum); | |
1922 | } | |
1923 | ||
1924 | static int cfqg_print_stat_recursive(struct seq_file *sf, void *v) | |
1925 | { | |
1926 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1927 | cfqg_prfill_stat_recursive, &blkcg_policy_cfq, | |
1928 | seq_cft(sf)->private, false); | |
1929 | return 0; | |
1930 | } | |
1931 | ||
1932 | static int cfqg_print_rwstat_recursive(struct seq_file *sf, void *v) | |
1933 | { | |
1934 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1935 | cfqg_prfill_rwstat_recursive, &blkcg_policy_cfq, | |
1936 | seq_cft(sf)->private, true); | |
1937 | return 0; | |
1938 | } | |
1939 | ||
1940 | static u64 cfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd, | |
1941 | int off) | |
1942 | { | |
1943 | u64 sum = blkg_rwstat_total(&pd->blkg->stat_bytes); | |
1944 | ||
1945 | return __blkg_prfill_u64(sf, pd, sum >> 9); | |
1946 | } | |
1947 | ||
1948 | static int cfqg_print_stat_sectors(struct seq_file *sf, void *v) | |
1949 | { | |
1950 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1951 | cfqg_prfill_sectors, &blkcg_policy_cfq, 0, false); | |
1952 | return 0; | |
1953 | } | |
1954 | ||
1955 | static u64 cfqg_prfill_sectors_recursive(struct seq_file *sf, | |
1956 | struct blkg_policy_data *pd, int off) | |
1957 | { | |
1958 | struct blkg_rwstat tmp = blkg_rwstat_recursive_sum(pd->blkg, NULL, | |
1959 | offsetof(struct blkcg_gq, stat_bytes)); | |
1960 | u64 sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) + | |
1961 | atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]); | |
1962 | ||
1963 | return __blkg_prfill_u64(sf, pd, sum >> 9); | |
1964 | } | |
1965 | ||
1966 | static int cfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v) | |
1967 | { | |
1968 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1969 | cfqg_prfill_sectors_recursive, &blkcg_policy_cfq, 0, | |
1970 | false); | |
1971 | return 0; | |
1972 | } | |
1973 | ||
1974 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
1975 | static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf, | |
1976 | struct blkg_policy_data *pd, int off) | |
1977 | { | |
1978 | struct cfq_group *cfqg = pd_to_cfqg(pd); | |
1979 | u64 samples = blkg_stat_read(&cfqg->stats.avg_queue_size_samples); | |
1980 | u64 v = 0; | |
1981 | ||
1982 | if (samples) { | |
1983 | v = blkg_stat_read(&cfqg->stats.avg_queue_size_sum); | |
1984 | v = div64_u64(v, samples); | |
1985 | } | |
1986 | __blkg_prfill_u64(sf, pd, v); | |
1987 | return 0; | |
1988 | } | |
1989 | ||
1990 | /* print avg_queue_size */ | |
1991 | static int cfqg_print_avg_queue_size(struct seq_file *sf, void *v) | |
1992 | { | |
1993 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1994 | cfqg_prfill_avg_queue_size, &blkcg_policy_cfq, | |
1995 | 0, false); | |
1996 | return 0; | |
1997 | } | |
1998 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
1999 | ||
2000 | static struct cftype cfq_blkcg_legacy_files[] = { | |
2001 | /* on root, weight is mapped to leaf_weight */ | |
2002 | { | |
2003 | .name = "weight_device", | |
2004 | .flags = CFTYPE_ONLY_ON_ROOT, | |
2005 | .seq_show = cfqg_print_leaf_weight_device, | |
2006 | .write = cfqg_set_leaf_weight_device, | |
2007 | }, | |
2008 | { | |
2009 | .name = "weight", | |
2010 | .flags = CFTYPE_ONLY_ON_ROOT, | |
2011 | .seq_show = cfq_print_leaf_weight, | |
2012 | .write_u64 = cfq_set_leaf_weight, | |
2013 | }, | |
2014 | ||
2015 | /* no such mapping necessary for !roots */ | |
2016 | { | |
2017 | .name = "weight_device", | |
2018 | .flags = CFTYPE_NOT_ON_ROOT, | |
2019 | .seq_show = cfqg_print_weight_device, | |
2020 | .write = cfqg_set_weight_device, | |
2021 | }, | |
2022 | { | |
2023 | .name = "weight", | |
2024 | .flags = CFTYPE_NOT_ON_ROOT, | |
2025 | .seq_show = cfq_print_weight, | |
2026 | .write_u64 = cfq_set_weight, | |
2027 | }, | |
2028 | ||
2029 | { | |
2030 | .name = "leaf_weight_device", | |
2031 | .seq_show = cfqg_print_leaf_weight_device, | |
2032 | .write = cfqg_set_leaf_weight_device, | |
2033 | }, | |
2034 | { | |
2035 | .name = "leaf_weight", | |
2036 | .seq_show = cfq_print_leaf_weight, | |
2037 | .write_u64 = cfq_set_leaf_weight, | |
2038 | }, | |
2039 | ||
2040 | /* statistics, covers only the tasks in the cfqg */ | |
2041 | { | |
2042 | .name = "time", | |
2043 | .private = offsetof(struct cfq_group, stats.time), | |
2044 | .seq_show = cfqg_print_stat, | |
2045 | }, | |
2046 | { | |
2047 | .name = "sectors", | |
2048 | .seq_show = cfqg_print_stat_sectors, | |
2049 | }, | |
2050 | { | |
2051 | .name = "io_service_bytes", | |
2052 | .private = (unsigned long)&blkcg_policy_cfq, | |
2053 | .seq_show = blkg_print_stat_bytes, | |
2054 | }, | |
2055 | { | |
2056 | .name = "io_serviced", | |
2057 | .private = (unsigned long)&blkcg_policy_cfq, | |
2058 | .seq_show = blkg_print_stat_ios, | |
2059 | }, | |
2060 | { | |
2061 | .name = "io_service_time", | |
2062 | .private = offsetof(struct cfq_group, stats.service_time), | |
2063 | .seq_show = cfqg_print_rwstat, | |
2064 | }, | |
2065 | { | |
2066 | .name = "io_wait_time", | |
2067 | .private = offsetof(struct cfq_group, stats.wait_time), | |
2068 | .seq_show = cfqg_print_rwstat, | |
2069 | }, | |
2070 | { | |
2071 | .name = "io_merged", | |
2072 | .private = offsetof(struct cfq_group, stats.merged), | |
2073 | .seq_show = cfqg_print_rwstat, | |
2074 | }, | |
2075 | { | |
2076 | .name = "io_queued", | |
2077 | .private = offsetof(struct cfq_group, stats.queued), | |
2078 | .seq_show = cfqg_print_rwstat, | |
2079 | }, | |
2080 | ||
2081 | /* the same statictics which cover the cfqg and its descendants */ | |
2082 | { | |
2083 | .name = "time_recursive", | |
2084 | .private = offsetof(struct cfq_group, stats.time), | |
2085 | .seq_show = cfqg_print_stat_recursive, | |
2086 | }, | |
2087 | { | |
2088 | .name = "sectors_recursive", | |
2089 | .seq_show = cfqg_print_stat_sectors_recursive, | |
2090 | }, | |
2091 | { | |
2092 | .name = "io_service_bytes_recursive", | |
2093 | .private = (unsigned long)&blkcg_policy_cfq, | |
2094 | .seq_show = blkg_print_stat_bytes_recursive, | |
2095 | }, | |
2096 | { | |
2097 | .name = "io_serviced_recursive", | |
2098 | .private = (unsigned long)&blkcg_policy_cfq, | |
2099 | .seq_show = blkg_print_stat_ios_recursive, | |
2100 | }, | |
2101 | { | |
2102 | .name = "io_service_time_recursive", | |
2103 | .private = offsetof(struct cfq_group, stats.service_time), | |
2104 | .seq_show = cfqg_print_rwstat_recursive, | |
2105 | }, | |
2106 | { | |
2107 | .name = "io_wait_time_recursive", | |
2108 | .private = offsetof(struct cfq_group, stats.wait_time), | |
2109 | .seq_show = cfqg_print_rwstat_recursive, | |
2110 | }, | |
2111 | { | |
2112 | .name = "io_merged_recursive", | |
2113 | .private = offsetof(struct cfq_group, stats.merged), | |
2114 | .seq_show = cfqg_print_rwstat_recursive, | |
2115 | }, | |
2116 | { | |
2117 | .name = "io_queued_recursive", | |
2118 | .private = offsetof(struct cfq_group, stats.queued), | |
2119 | .seq_show = cfqg_print_rwstat_recursive, | |
2120 | }, | |
2121 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
2122 | { | |
2123 | .name = "avg_queue_size", | |
2124 | .seq_show = cfqg_print_avg_queue_size, | |
2125 | }, | |
2126 | { | |
2127 | .name = "group_wait_time", | |
2128 | .private = offsetof(struct cfq_group, stats.group_wait_time), | |
2129 | .seq_show = cfqg_print_stat, | |
2130 | }, | |
2131 | { | |
2132 | .name = "idle_time", | |
2133 | .private = offsetof(struct cfq_group, stats.idle_time), | |
2134 | .seq_show = cfqg_print_stat, | |
2135 | }, | |
2136 | { | |
2137 | .name = "empty_time", | |
2138 | .private = offsetof(struct cfq_group, stats.empty_time), | |
2139 | .seq_show = cfqg_print_stat, | |
2140 | }, | |
2141 | { | |
2142 | .name = "dequeue", | |
2143 | .private = offsetof(struct cfq_group, stats.dequeue), | |
2144 | .seq_show = cfqg_print_stat, | |
2145 | }, | |
2146 | { | |
2147 | .name = "unaccounted_time", | |
2148 | .private = offsetof(struct cfq_group, stats.unaccounted_time), | |
2149 | .seq_show = cfqg_print_stat, | |
2150 | }, | |
2151 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
2152 | { } /* terminate */ | |
2153 | }; | |
2154 | ||
2155 | static int cfq_print_weight_on_dfl(struct seq_file *sf, void *v) | |
2156 | { | |
2157 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); | |
2158 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg); | |
2159 | ||
2160 | seq_printf(sf, "default %u\n", cgd->weight); | |
2161 | blkcg_print_blkgs(sf, blkcg, cfqg_prfill_weight_device, | |
2162 | &blkcg_policy_cfq, 0, false); | |
2163 | return 0; | |
2164 | } | |
2165 | ||
2166 | static ssize_t cfq_set_weight_on_dfl(struct kernfs_open_file *of, | |
2167 | char *buf, size_t nbytes, loff_t off) | |
2168 | { | |
2169 | char *endp; | |
2170 | int ret; | |
2171 | u64 v; | |
2172 | ||
2173 | buf = strim(buf); | |
2174 | ||
2175 | /* "WEIGHT" or "default WEIGHT" sets the default weight */ | |
2176 | v = simple_strtoull(buf, &endp, 0); | |
2177 | if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) { | |
2178 | ret = __cfq_set_weight(of_css(of), v, true, false, false); | |
2179 | return ret ?: nbytes; | |
2180 | } | |
2181 | ||
2182 | /* "MAJ:MIN WEIGHT" */ | |
2183 | return __cfqg_set_weight_device(of, buf, nbytes, off, true, false); | |
2184 | } | |
2185 | ||
2186 | static struct cftype cfq_blkcg_files[] = { | |
2187 | { | |
2188 | .name = "weight", | |
2189 | .flags = CFTYPE_NOT_ON_ROOT, | |
2190 | .seq_show = cfq_print_weight_on_dfl, | |
2191 | .write = cfq_set_weight_on_dfl, | |
2192 | }, | |
2193 | { } /* terminate */ | |
2194 | }; | |
2195 | ||
2196 | #else /* GROUP_IOSCHED */ | |
2197 | static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd, | |
2198 | struct blkcg *blkcg) | |
2199 | { | |
2200 | return cfqd->root_group; | |
2201 | } | |
2202 | ||
2203 | static inline void | |
2204 | cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { | |
2205 | cfqq->cfqg = cfqg; | |
2206 | } | |
2207 | ||
2208 | #endif /* GROUP_IOSCHED */ | |
2209 | ||
2210 | /* | |
2211 | * The cfqd->service_trees holds all pending cfq_queue's that have | |
2212 | * requests waiting to be processed. It is sorted in the order that | |
2213 | * we will service the queues. | |
2214 | */ | |
2215 | static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
2216 | bool add_front) | |
2217 | { | |
2218 | struct rb_node **p, *parent; | |
2219 | struct cfq_queue *__cfqq; | |
2220 | u64 rb_key; | |
2221 | struct cfq_rb_root *st; | |
2222 | int left; | |
2223 | int new_cfqq = 1; | |
2224 | u64 now = ktime_get_ns(); | |
2225 | ||
2226 | st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq)); | |
2227 | if (cfq_class_idle(cfqq)) { | |
2228 | rb_key = CFQ_IDLE_DELAY; | |
2229 | parent = rb_last(&st->rb); | |
2230 | if (parent && parent != &cfqq->rb_node) { | |
2231 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); | |
2232 | rb_key += __cfqq->rb_key; | |
2233 | } else | |
2234 | rb_key += now; | |
2235 | } else if (!add_front) { | |
2236 | /* | |
2237 | * Get our rb key offset. Subtract any residual slice | |
2238 | * value carried from last service. A negative resid | |
2239 | * count indicates slice overrun, and this should position | |
2240 | * the next service time further away in the tree. | |
2241 | */ | |
2242 | rb_key = cfq_slice_offset(cfqd, cfqq) + now; | |
2243 | rb_key -= cfqq->slice_resid; | |
2244 | cfqq->slice_resid = 0; | |
2245 | } else { | |
2246 | rb_key = -NSEC_PER_SEC; | |
2247 | __cfqq = cfq_rb_first(st); | |
2248 | rb_key += __cfqq ? __cfqq->rb_key : now; | |
2249 | } | |
2250 | ||
2251 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { | |
2252 | new_cfqq = 0; | |
2253 | /* | |
2254 | * same position, nothing more to do | |
2255 | */ | |
2256 | if (rb_key == cfqq->rb_key && cfqq->service_tree == st) | |
2257 | return; | |
2258 | ||
2259 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); | |
2260 | cfqq->service_tree = NULL; | |
2261 | } | |
2262 | ||
2263 | left = 1; | |
2264 | parent = NULL; | |
2265 | cfqq->service_tree = st; | |
2266 | p = &st->rb.rb_node; | |
2267 | while (*p) { | |
2268 | parent = *p; | |
2269 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); | |
2270 | ||
2271 | /* | |
2272 | * sort by key, that represents service time. | |
2273 | */ | |
2274 | if (rb_key < __cfqq->rb_key) | |
2275 | p = &parent->rb_left; | |
2276 | else { | |
2277 | p = &parent->rb_right; | |
2278 | left = 0; | |
2279 | } | |
2280 | } | |
2281 | ||
2282 | if (left) | |
2283 | st->left = &cfqq->rb_node; | |
2284 | ||
2285 | cfqq->rb_key = rb_key; | |
2286 | rb_link_node(&cfqq->rb_node, parent, p); | |
2287 | rb_insert_color(&cfqq->rb_node, &st->rb); | |
2288 | st->count++; | |
2289 | if (add_front || !new_cfqq) | |
2290 | return; | |
2291 | cfq_group_notify_queue_add(cfqd, cfqq->cfqg); | |
2292 | } | |
2293 | ||
2294 | static struct cfq_queue * | |
2295 | cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, | |
2296 | sector_t sector, struct rb_node **ret_parent, | |
2297 | struct rb_node ***rb_link) | |
2298 | { | |
2299 | struct rb_node **p, *parent; | |
2300 | struct cfq_queue *cfqq = NULL; | |
2301 | ||
2302 | parent = NULL; | |
2303 | p = &root->rb_node; | |
2304 | while (*p) { | |
2305 | struct rb_node **n; | |
2306 | ||
2307 | parent = *p; | |
2308 | cfqq = rb_entry(parent, struct cfq_queue, p_node); | |
2309 | ||
2310 | /* | |
2311 | * Sort strictly based on sector. Smallest to the left, | |
2312 | * largest to the right. | |
2313 | */ | |
2314 | if (sector > blk_rq_pos(cfqq->next_rq)) | |
2315 | n = &(*p)->rb_right; | |
2316 | else if (sector < blk_rq_pos(cfqq->next_rq)) | |
2317 | n = &(*p)->rb_left; | |
2318 | else | |
2319 | break; | |
2320 | p = n; | |
2321 | cfqq = NULL; | |
2322 | } | |
2323 | ||
2324 | *ret_parent = parent; | |
2325 | if (rb_link) | |
2326 | *rb_link = p; | |
2327 | return cfqq; | |
2328 | } | |
2329 | ||
2330 | static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2331 | { | |
2332 | struct rb_node **p, *parent; | |
2333 | struct cfq_queue *__cfqq; | |
2334 | ||
2335 | if (cfqq->p_root) { | |
2336 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2337 | cfqq->p_root = NULL; | |
2338 | } | |
2339 | ||
2340 | if (cfq_class_idle(cfqq)) | |
2341 | return; | |
2342 | if (!cfqq->next_rq) | |
2343 | return; | |
2344 | ||
2345 | cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; | |
2346 | __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, | |
2347 | blk_rq_pos(cfqq->next_rq), &parent, &p); | |
2348 | if (!__cfqq) { | |
2349 | rb_link_node(&cfqq->p_node, parent, p); | |
2350 | rb_insert_color(&cfqq->p_node, cfqq->p_root); | |
2351 | } else | |
2352 | cfqq->p_root = NULL; | |
2353 | } | |
2354 | ||
2355 | /* | |
2356 | * Update cfqq's position in the service tree. | |
2357 | */ | |
2358 | static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2359 | { | |
2360 | /* | |
2361 | * Resorting requires the cfqq to be on the RR list already. | |
2362 | */ | |
2363 | if (cfq_cfqq_on_rr(cfqq)) { | |
2364 | cfq_service_tree_add(cfqd, cfqq, 0); | |
2365 | cfq_prio_tree_add(cfqd, cfqq); | |
2366 | } | |
2367 | } | |
2368 | ||
2369 | /* | |
2370 | * add to busy list of queues for service, trying to be fair in ordering | |
2371 | * the pending list according to last request service | |
2372 | */ | |
2373 | static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2374 | { | |
2375 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); | |
2376 | BUG_ON(cfq_cfqq_on_rr(cfqq)); | |
2377 | cfq_mark_cfqq_on_rr(cfqq); | |
2378 | cfqd->busy_queues++; | |
2379 | if (cfq_cfqq_sync(cfqq)) | |
2380 | cfqd->busy_sync_queues++; | |
2381 | ||
2382 | cfq_resort_rr_list(cfqd, cfqq); | |
2383 | } | |
2384 | ||
2385 | /* | |
2386 | * Called when the cfqq no longer has requests pending, remove it from | |
2387 | * the service tree. | |
2388 | */ | |
2389 | static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2390 | { | |
2391 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); | |
2392 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); | |
2393 | cfq_clear_cfqq_on_rr(cfqq); | |
2394 | ||
2395 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { | |
2396 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); | |
2397 | cfqq->service_tree = NULL; | |
2398 | } | |
2399 | if (cfqq->p_root) { | |
2400 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2401 | cfqq->p_root = NULL; | |
2402 | } | |
2403 | ||
2404 | cfq_group_notify_queue_del(cfqd, cfqq->cfqg); | |
2405 | BUG_ON(!cfqd->busy_queues); | |
2406 | cfqd->busy_queues--; | |
2407 | if (cfq_cfqq_sync(cfqq)) | |
2408 | cfqd->busy_sync_queues--; | |
2409 | } | |
2410 | ||
2411 | /* | |
2412 | * rb tree support functions | |
2413 | */ | |
2414 | static void cfq_del_rq_rb(struct request *rq) | |
2415 | { | |
2416 | struct cfq_queue *cfqq = RQ_CFQQ(rq); | |
2417 | const int sync = rq_is_sync(rq); | |
2418 | ||
2419 | BUG_ON(!cfqq->queued[sync]); | |
2420 | cfqq->queued[sync]--; | |
2421 | ||
2422 | elv_rb_del(&cfqq->sort_list, rq); | |
2423 | ||
2424 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) { | |
2425 | /* | |
2426 | * Queue will be deleted from service tree when we actually | |
2427 | * expire it later. Right now just remove it from prio tree | |
2428 | * as it is empty. | |
2429 | */ | |
2430 | if (cfqq->p_root) { | |
2431 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2432 | cfqq->p_root = NULL; | |
2433 | } | |
2434 | } | |
2435 | } | |
2436 | ||
2437 | static void cfq_add_rq_rb(struct request *rq) | |
2438 | { | |
2439 | struct cfq_queue *cfqq = RQ_CFQQ(rq); | |
2440 | struct cfq_data *cfqd = cfqq->cfqd; | |
2441 | struct request *prev; | |
2442 | ||
2443 | cfqq->queued[rq_is_sync(rq)]++; | |
2444 | ||
2445 | elv_rb_add(&cfqq->sort_list, rq); | |
2446 | ||
2447 | if (!cfq_cfqq_on_rr(cfqq)) | |
2448 | cfq_add_cfqq_rr(cfqd, cfqq); | |
2449 | ||
2450 | /* | |
2451 | * check if this request is a better next-serve candidate | |
2452 | */ | |
2453 | prev = cfqq->next_rq; | |
2454 | cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq, cfqd->last_position); | |
2455 | ||
2456 | /* | |
2457 | * adjust priority tree position, if ->next_rq changes | |
2458 | */ | |
2459 | if (prev != cfqq->next_rq) | |
2460 | cfq_prio_tree_add(cfqd, cfqq); | |
2461 | ||
2462 | BUG_ON(!cfqq->next_rq); | |
2463 | } | |
2464 | ||
2465 | static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq) | |
2466 | { | |
2467 | elv_rb_del(&cfqq->sort_list, rq); | |
2468 | cfqq->queued[rq_is_sync(rq)]--; | |
2469 | cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags); | |
2470 | cfq_add_rq_rb(rq); | |
2471 | cfqg_stats_update_io_add(RQ_CFQG(rq), cfqq->cfqd->serving_group, | |
2472 | rq->cmd_flags); | |
2473 | } | |
2474 | ||
2475 | static struct request * | |
2476 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) | |
2477 | { | |
2478 | struct task_struct *tsk = current; | |
2479 | struct cfq_io_cq *cic; | |
2480 | struct cfq_queue *cfqq; | |
2481 | ||
2482 | cic = cfq_cic_lookup(cfqd, tsk->io_context); | |
2483 | if (!cic) | |
2484 | return NULL; | |
2485 | ||
2486 | cfqq = cic_to_cfqq(cic, op_is_sync(bio->bi_opf)); | |
2487 | if (cfqq) | |
2488 | return elv_rb_find(&cfqq->sort_list, bio_end_sector(bio)); | |
2489 | ||
2490 | return NULL; | |
2491 | } | |
2492 | ||
2493 | static void cfq_activate_request(struct request_queue *q, struct request *rq) | |
2494 | { | |
2495 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
2496 | ||
2497 | cfqd->rq_in_driver++; | |
2498 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", | |
2499 | cfqd->rq_in_driver); | |
2500 | ||
2501 | cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); | |
2502 | } | |
2503 | ||
2504 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) | |
2505 | { | |
2506 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
2507 | ||
2508 | WARN_ON(!cfqd->rq_in_driver); | |
2509 | cfqd->rq_in_driver--; | |
2510 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", | |
2511 | cfqd->rq_in_driver); | |
2512 | } | |
2513 | ||
2514 | static void cfq_remove_request(struct request *rq) | |
2515 | { | |
2516 | struct cfq_queue *cfqq = RQ_CFQQ(rq); | |
2517 | ||
2518 | if (cfqq->next_rq == rq) | |
2519 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); | |
2520 | ||
2521 | list_del_init(&rq->queuelist); | |
2522 | cfq_del_rq_rb(rq); | |
2523 | ||
2524 | cfqq->cfqd->rq_queued--; | |
2525 | cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags); | |
2526 | if (rq->cmd_flags & REQ_PRIO) { | |
2527 | WARN_ON(!cfqq->prio_pending); | |
2528 | cfqq->prio_pending--; | |
2529 | } | |
2530 | } | |
2531 | ||
2532 | static enum elv_merge cfq_merge(struct request_queue *q, struct request **req, | |
2533 | struct bio *bio) | |
2534 | { | |
2535 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
2536 | struct request *__rq; | |
2537 | ||
2538 | __rq = cfq_find_rq_fmerge(cfqd, bio); | |
2539 | if (__rq && elv_bio_merge_ok(__rq, bio)) { | |
2540 | *req = __rq; | |
2541 | return ELEVATOR_FRONT_MERGE; | |
2542 | } | |
2543 | ||
2544 | return ELEVATOR_NO_MERGE; | |
2545 | } | |
2546 | ||
2547 | static void cfq_merged_request(struct request_queue *q, struct request *req, | |
2548 | enum elv_merge type) | |
2549 | { | |
2550 | if (type == ELEVATOR_FRONT_MERGE) { | |
2551 | struct cfq_queue *cfqq = RQ_CFQQ(req); | |
2552 | ||
2553 | cfq_reposition_rq_rb(cfqq, req); | |
2554 | } | |
2555 | } | |
2556 | ||
2557 | static void cfq_bio_merged(struct request_queue *q, struct request *req, | |
2558 | struct bio *bio) | |
2559 | { | |
2560 | cfqg_stats_update_io_merged(RQ_CFQG(req), bio->bi_opf); | |
2561 | } | |
2562 | ||
2563 | static void | |
2564 | cfq_merged_requests(struct request_queue *q, struct request *rq, | |
2565 | struct request *next) | |
2566 | { | |
2567 | struct cfq_queue *cfqq = RQ_CFQQ(rq); | |
2568 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
2569 | ||
2570 | /* | |
2571 | * reposition in fifo if next is older than rq | |
2572 | */ | |
2573 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && | |
2574 | next->fifo_time < rq->fifo_time && | |
2575 | cfqq == RQ_CFQQ(next)) { | |
2576 | list_move(&rq->queuelist, &next->queuelist); | |
2577 | rq->fifo_time = next->fifo_time; | |
2578 | } | |
2579 | ||
2580 | if (cfqq->next_rq == next) | |
2581 | cfqq->next_rq = rq; | |
2582 | cfq_remove_request(next); | |
2583 | cfqg_stats_update_io_merged(RQ_CFQG(rq), next->cmd_flags); | |
2584 | ||
2585 | cfqq = RQ_CFQQ(next); | |
2586 | /* | |
2587 | * all requests of this queue are merged to other queues, delete it | |
2588 | * from the service tree. If it's the active_queue, | |
2589 | * cfq_dispatch_requests() will choose to expire it or do idle | |
2590 | */ | |
2591 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list) && | |
2592 | cfqq != cfqd->active_queue) | |
2593 | cfq_del_cfqq_rr(cfqd, cfqq); | |
2594 | } | |
2595 | ||
2596 | static int cfq_allow_bio_merge(struct request_queue *q, struct request *rq, | |
2597 | struct bio *bio) | |
2598 | { | |
2599 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
2600 | bool is_sync = op_is_sync(bio->bi_opf); | |
2601 | struct cfq_io_cq *cic; | |
2602 | struct cfq_queue *cfqq; | |
2603 | ||
2604 | /* | |
2605 | * Disallow merge of a sync bio into an async request. | |
2606 | */ | |
2607 | if (is_sync && !rq_is_sync(rq)) | |
2608 | return false; | |
2609 | ||
2610 | /* | |
2611 | * Lookup the cfqq that this bio will be queued with and allow | |
2612 | * merge only if rq is queued there. | |
2613 | */ | |
2614 | cic = cfq_cic_lookup(cfqd, current->io_context); | |
2615 | if (!cic) | |
2616 | return false; | |
2617 | ||
2618 | cfqq = cic_to_cfqq(cic, is_sync); | |
2619 | return cfqq == RQ_CFQQ(rq); | |
2620 | } | |
2621 | ||
2622 | static int cfq_allow_rq_merge(struct request_queue *q, struct request *rq, | |
2623 | struct request *next) | |
2624 | { | |
2625 | return RQ_CFQQ(rq) == RQ_CFQQ(next); | |
2626 | } | |
2627 | ||
2628 | static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2629 | { | |
2630 | hrtimer_try_to_cancel(&cfqd->idle_slice_timer); | |
2631 | cfqg_stats_update_idle_time(cfqq->cfqg); | |
2632 | } | |
2633 | ||
2634 | static void __cfq_set_active_queue(struct cfq_data *cfqd, | |
2635 | struct cfq_queue *cfqq) | |
2636 | { | |
2637 | if (cfqq) { | |
2638 | cfq_log_cfqq(cfqd, cfqq, "set_active wl_class:%d wl_type:%d", | |
2639 | cfqd->serving_wl_class, cfqd->serving_wl_type); | |
2640 | cfqg_stats_update_avg_queue_size(cfqq->cfqg); | |
2641 | cfqq->slice_start = 0; | |
2642 | cfqq->dispatch_start = ktime_get_ns(); | |
2643 | cfqq->allocated_slice = 0; | |
2644 | cfqq->slice_end = 0; | |
2645 | cfqq->slice_dispatch = 0; | |
2646 | cfqq->nr_sectors = 0; | |
2647 | ||
2648 | cfq_clear_cfqq_wait_request(cfqq); | |
2649 | cfq_clear_cfqq_must_dispatch(cfqq); | |
2650 | cfq_clear_cfqq_must_alloc_slice(cfqq); | |
2651 | cfq_clear_cfqq_fifo_expire(cfqq); | |
2652 | cfq_mark_cfqq_slice_new(cfqq); | |
2653 | ||
2654 | cfq_del_timer(cfqd, cfqq); | |
2655 | } | |
2656 | ||
2657 | cfqd->active_queue = cfqq; | |
2658 | } | |
2659 | ||
2660 | /* | |
2661 | * current cfqq expired its slice (or was too idle), select new one | |
2662 | */ | |
2663 | static void | |
2664 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
2665 | bool timed_out) | |
2666 | { | |
2667 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); | |
2668 | ||
2669 | if (cfq_cfqq_wait_request(cfqq)) | |
2670 | cfq_del_timer(cfqd, cfqq); | |
2671 | ||
2672 | cfq_clear_cfqq_wait_request(cfqq); | |
2673 | cfq_clear_cfqq_wait_busy(cfqq); | |
2674 | ||
2675 | /* | |
2676 | * If this cfqq is shared between multiple processes, check to | |
2677 | * make sure that those processes are still issuing I/Os within | |
2678 | * the mean seek distance. If not, it may be time to break the | |
2679 | * queues apart again. | |
2680 | */ | |
2681 | if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq)) | |
2682 | cfq_mark_cfqq_split_coop(cfqq); | |
2683 | ||
2684 | /* | |
2685 | * store what was left of this slice, if the queue idled/timed out | |
2686 | */ | |
2687 | if (timed_out) { | |
2688 | if (cfq_cfqq_slice_new(cfqq)) | |
2689 | cfqq->slice_resid = cfq_scaled_cfqq_slice(cfqd, cfqq); | |
2690 | else | |
2691 | cfqq->slice_resid = cfqq->slice_end - ktime_get_ns(); | |
2692 | cfq_log_cfqq(cfqd, cfqq, "resid=%lld", cfqq->slice_resid); | |
2693 | } | |
2694 | ||
2695 | cfq_group_served(cfqd, cfqq->cfqg, cfqq); | |
2696 | ||
2697 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) | |
2698 | cfq_del_cfqq_rr(cfqd, cfqq); | |
2699 | ||
2700 | cfq_resort_rr_list(cfqd, cfqq); | |
2701 | ||
2702 | if (cfqq == cfqd->active_queue) | |
2703 | cfqd->active_queue = NULL; | |
2704 | ||
2705 | if (cfqd->active_cic) { | |
2706 | put_io_context(cfqd->active_cic->icq.ioc); | |
2707 | cfqd->active_cic = NULL; | |
2708 | } | |
2709 | } | |
2710 | ||
2711 | static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out) | |
2712 | { | |
2713 | struct cfq_queue *cfqq = cfqd->active_queue; | |
2714 | ||
2715 | if (cfqq) | |
2716 | __cfq_slice_expired(cfqd, cfqq, timed_out); | |
2717 | } | |
2718 | ||
2719 | /* | |
2720 | * Get next queue for service. Unless we have a queue preemption, | |
2721 | * we'll simply select the first cfqq in the service tree. | |
2722 | */ | |
2723 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) | |
2724 | { | |
2725 | struct cfq_rb_root *st = st_for(cfqd->serving_group, | |
2726 | cfqd->serving_wl_class, cfqd->serving_wl_type); | |
2727 | ||
2728 | if (!cfqd->rq_queued) | |
2729 | return NULL; | |
2730 | ||
2731 | /* There is nothing to dispatch */ | |
2732 | if (!st) | |
2733 | return NULL; | |
2734 | if (RB_EMPTY_ROOT(&st->rb)) | |
2735 | return NULL; | |
2736 | return cfq_rb_first(st); | |
2737 | } | |
2738 | ||
2739 | static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd) | |
2740 | { | |
2741 | struct cfq_group *cfqg; | |
2742 | struct cfq_queue *cfqq; | |
2743 | int i, j; | |
2744 | struct cfq_rb_root *st; | |
2745 | ||
2746 | if (!cfqd->rq_queued) | |
2747 | return NULL; | |
2748 | ||
2749 | cfqg = cfq_get_next_cfqg(cfqd); | |
2750 | if (!cfqg) | |
2751 | return NULL; | |
2752 | ||
2753 | for_each_cfqg_st(cfqg, i, j, st) { | |
2754 | cfqq = cfq_rb_first(st); | |
2755 | if (cfqq) | |
2756 | return cfqq; | |
2757 | } | |
2758 | return NULL; | |
2759 | } | |
2760 | ||
2761 | /* | |
2762 | * Get and set a new active queue for service. | |
2763 | */ | |
2764 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, | |
2765 | struct cfq_queue *cfqq) | |
2766 | { | |
2767 | if (!cfqq) | |
2768 | cfqq = cfq_get_next_queue(cfqd); | |
2769 | ||
2770 | __cfq_set_active_queue(cfqd, cfqq); | |
2771 | return cfqq; | |
2772 | } | |
2773 | ||
2774 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, | |
2775 | struct request *rq) | |
2776 | { | |
2777 | if (blk_rq_pos(rq) >= cfqd->last_position) | |
2778 | return blk_rq_pos(rq) - cfqd->last_position; | |
2779 | else | |
2780 | return cfqd->last_position - blk_rq_pos(rq); | |
2781 | } | |
2782 | ||
2783 | static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
2784 | struct request *rq) | |
2785 | { | |
2786 | return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR; | |
2787 | } | |
2788 | ||
2789 | static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, | |
2790 | struct cfq_queue *cur_cfqq) | |
2791 | { | |
2792 | struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; | |
2793 | struct rb_node *parent, *node; | |
2794 | struct cfq_queue *__cfqq; | |
2795 | sector_t sector = cfqd->last_position; | |
2796 | ||
2797 | if (RB_EMPTY_ROOT(root)) | |
2798 | return NULL; | |
2799 | ||
2800 | /* | |
2801 | * First, if we find a request starting at the end of the last | |
2802 | * request, choose it. | |
2803 | */ | |
2804 | __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); | |
2805 | if (__cfqq) | |
2806 | return __cfqq; | |
2807 | ||
2808 | /* | |
2809 | * If the exact sector wasn't found, the parent of the NULL leaf | |
2810 | * will contain the closest sector. | |
2811 | */ | |
2812 | __cfqq = rb_entry(parent, struct cfq_queue, p_node); | |
2813 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) | |
2814 | return __cfqq; | |
2815 | ||
2816 | if (blk_rq_pos(__cfqq->next_rq) < sector) | |
2817 | node = rb_next(&__cfqq->p_node); | |
2818 | else | |
2819 | node = rb_prev(&__cfqq->p_node); | |
2820 | if (!node) | |
2821 | return NULL; | |
2822 | ||
2823 | __cfqq = rb_entry(node, struct cfq_queue, p_node); | |
2824 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) | |
2825 | return __cfqq; | |
2826 | ||
2827 | return NULL; | |
2828 | } | |
2829 | ||
2830 | /* | |
2831 | * cfqd - obvious | |
2832 | * cur_cfqq - passed in so that we don't decide that the current queue is | |
2833 | * closely cooperating with itself. | |
2834 | * | |
2835 | * So, basically we're assuming that that cur_cfqq has dispatched at least | |
2836 | * one request, and that cfqd->last_position reflects a position on the disk | |
2837 | * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid | |
2838 | * assumption. | |
2839 | */ | |
2840 | static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, | |
2841 | struct cfq_queue *cur_cfqq) | |
2842 | { | |
2843 | struct cfq_queue *cfqq; | |
2844 | ||
2845 | if (cfq_class_idle(cur_cfqq)) | |
2846 | return NULL; | |
2847 | if (!cfq_cfqq_sync(cur_cfqq)) | |
2848 | return NULL; | |
2849 | if (CFQQ_SEEKY(cur_cfqq)) | |
2850 | return NULL; | |
2851 | ||
2852 | /* | |
2853 | * Don't search priority tree if it's the only queue in the group. | |
2854 | */ | |
2855 | if (cur_cfqq->cfqg->nr_cfqq == 1) | |
2856 | return NULL; | |
2857 | ||
2858 | /* | |
2859 | * We should notice if some of the queues are cooperating, eg | |
2860 | * working closely on the same area of the disk. In that case, | |
2861 | * we can group them together and don't waste time idling. | |
2862 | */ | |
2863 | cfqq = cfqq_close(cfqd, cur_cfqq); | |
2864 | if (!cfqq) | |
2865 | return NULL; | |
2866 | ||
2867 | /* If new queue belongs to different cfq_group, don't choose it */ | |
2868 | if (cur_cfqq->cfqg != cfqq->cfqg) | |
2869 | return NULL; | |
2870 | ||
2871 | /* | |
2872 | * It only makes sense to merge sync queues. | |
2873 | */ | |
2874 | if (!cfq_cfqq_sync(cfqq)) | |
2875 | return NULL; | |
2876 | if (CFQQ_SEEKY(cfqq)) | |
2877 | return NULL; | |
2878 | ||
2879 | /* | |
2880 | * Do not merge queues of different priority classes | |
2881 | */ | |
2882 | if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq)) | |
2883 | return NULL; | |
2884 | ||
2885 | return cfqq; | |
2886 | } | |
2887 | ||
2888 | /* | |
2889 | * Determine whether we should enforce idle window for this queue. | |
2890 | */ | |
2891 | ||
2892 | static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2893 | { | |
2894 | enum wl_class_t wl_class = cfqq_class(cfqq); | |
2895 | struct cfq_rb_root *st = cfqq->service_tree; | |
2896 | ||
2897 | BUG_ON(!st); | |
2898 | BUG_ON(!st->count); | |
2899 | ||
2900 | if (!cfqd->cfq_slice_idle) | |
2901 | return false; | |
2902 | ||
2903 | /* We never do for idle class queues. */ | |
2904 | if (wl_class == IDLE_WORKLOAD) | |
2905 | return false; | |
2906 | ||
2907 | /* We do for queues that were marked with idle window flag. */ | |
2908 | if (cfq_cfqq_idle_window(cfqq) && | |
2909 | !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)) | |
2910 | return true; | |
2911 | ||
2912 | /* | |
2913 | * Otherwise, we do only if they are the last ones | |
2914 | * in their service tree. | |
2915 | */ | |
2916 | if (st->count == 1 && cfq_cfqq_sync(cfqq) && | |
2917 | !cfq_io_thinktime_big(cfqd, &st->ttime, false)) | |
2918 | return true; | |
2919 | cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", st->count); | |
2920 | return false; | |
2921 | } | |
2922 | ||
2923 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) | |
2924 | { | |
2925 | struct cfq_queue *cfqq = cfqd->active_queue; | |
2926 | struct cfq_rb_root *st = cfqq->service_tree; | |
2927 | struct cfq_io_cq *cic; | |
2928 | u64 sl, group_idle = 0; | |
2929 | u64 now = ktime_get_ns(); | |
2930 | ||
2931 | /* | |
2932 | * SSD device without seek penalty, disable idling. But only do so | |
2933 | * for devices that support queuing, otherwise we still have a problem | |
2934 | * with sync vs async workloads. | |
2935 | */ | |
2936 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) | |
2937 | return; | |
2938 | ||
2939 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); | |
2940 | WARN_ON(cfq_cfqq_slice_new(cfqq)); | |
2941 | ||
2942 | /* | |
2943 | * idle is disabled, either manually or by past process history | |
2944 | */ | |
2945 | if (!cfq_should_idle(cfqd, cfqq)) { | |
2946 | /* no queue idling. Check for group idling */ | |
2947 | if (cfqd->cfq_group_idle) | |
2948 | group_idle = cfqd->cfq_group_idle; | |
2949 | else | |
2950 | return; | |
2951 | } | |
2952 | ||
2953 | /* | |
2954 | * still active requests from this queue, don't idle | |
2955 | */ | |
2956 | if (cfqq->dispatched) | |
2957 | return; | |
2958 | ||
2959 | /* | |
2960 | * task has exited, don't wait | |
2961 | */ | |
2962 | cic = cfqd->active_cic; | |
2963 | if (!cic || !atomic_read(&cic->icq.ioc->active_ref)) | |
2964 | return; | |
2965 | ||
2966 | /* | |
2967 | * If our average think time is larger than the remaining time | |
2968 | * slice, then don't idle. This avoids overrunning the allotted | |
2969 | * time slice. | |
2970 | */ | |
2971 | if (sample_valid(cic->ttime.ttime_samples) && | |
2972 | (cfqq->slice_end - now < cic->ttime.ttime_mean)) { | |
2973 | cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%llu", | |
2974 | cic->ttime.ttime_mean); | |
2975 | return; | |
2976 | } | |
2977 | ||
2978 | /* | |
2979 | * There are other queues in the group or this is the only group and | |
2980 | * it has too big thinktime, don't do group idle. | |
2981 | */ | |
2982 | if (group_idle && | |
2983 | (cfqq->cfqg->nr_cfqq > 1 || | |
2984 | cfq_io_thinktime_big(cfqd, &st->ttime, true))) | |
2985 | return; | |
2986 | ||
2987 | cfq_mark_cfqq_wait_request(cfqq); | |
2988 | ||
2989 | if (group_idle) | |
2990 | sl = cfqd->cfq_group_idle; | |
2991 | else | |
2992 | sl = cfqd->cfq_slice_idle; | |
2993 | ||
2994 | hrtimer_start(&cfqd->idle_slice_timer, ns_to_ktime(sl), | |
2995 | HRTIMER_MODE_REL); | |
2996 | cfqg_stats_set_start_idle_time(cfqq->cfqg); | |
2997 | cfq_log_cfqq(cfqd, cfqq, "arm_idle: %llu group_idle: %d", sl, | |
2998 | group_idle ? 1 : 0); | |
2999 | } | |
3000 | ||
3001 | /* | |
3002 | * Move request from internal lists to the request queue dispatch list. | |
3003 | */ | |
3004 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) | |
3005 | { | |
3006 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
3007 | struct cfq_queue *cfqq = RQ_CFQQ(rq); | |
3008 | ||
3009 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); | |
3010 | ||
3011 | cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); | |
3012 | cfq_remove_request(rq); | |
3013 | cfqq->dispatched++; | |
3014 | (RQ_CFQG(rq))->dispatched++; | |
3015 | elv_dispatch_sort(q, rq); | |
3016 | ||
3017 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++; | |
3018 | cfqq->nr_sectors += blk_rq_sectors(rq); | |
3019 | } | |
3020 | ||
3021 | /* | |
3022 | * return expired entry, or NULL to just start from scratch in rbtree | |
3023 | */ | |
3024 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) | |
3025 | { | |
3026 | struct request *rq = NULL; | |
3027 | ||
3028 | if (cfq_cfqq_fifo_expire(cfqq)) | |
3029 | return NULL; | |
3030 | ||
3031 | cfq_mark_cfqq_fifo_expire(cfqq); | |
3032 | ||
3033 | if (list_empty(&cfqq->fifo)) | |
3034 | return NULL; | |
3035 | ||
3036 | rq = rq_entry_fifo(cfqq->fifo.next); | |
3037 | if (ktime_get_ns() < rq->fifo_time) | |
3038 | rq = NULL; | |
3039 | ||
3040 | return rq; | |
3041 | } | |
3042 | ||
3043 | static inline int | |
3044 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3045 | { | |
3046 | const int base_rq = cfqd->cfq_slice_async_rq; | |
3047 | ||
3048 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); | |
3049 | ||
3050 | return 2 * base_rq * (IOPRIO_BE_NR - cfqq->ioprio); | |
3051 | } | |
3052 | ||
3053 | /* | |
3054 | * Must be called with the queue_lock held. | |
3055 | */ | |
3056 | static int cfqq_process_refs(struct cfq_queue *cfqq) | |
3057 | { | |
3058 | int process_refs, io_refs; | |
3059 | ||
3060 | io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE]; | |
3061 | process_refs = cfqq->ref - io_refs; | |
3062 | BUG_ON(process_refs < 0); | |
3063 | return process_refs; | |
3064 | } | |
3065 | ||
3066 | static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) | |
3067 | { | |
3068 | int process_refs, new_process_refs; | |
3069 | struct cfq_queue *__cfqq; | |
3070 | ||
3071 | /* | |
3072 | * If there are no process references on the new_cfqq, then it is | |
3073 | * unsafe to follow the ->new_cfqq chain as other cfqq's in the | |
3074 | * chain may have dropped their last reference (not just their | |
3075 | * last process reference). | |
3076 | */ | |
3077 | if (!cfqq_process_refs(new_cfqq)) | |
3078 | return; | |
3079 | ||
3080 | /* Avoid a circular list and skip interim queue merges */ | |
3081 | while ((__cfqq = new_cfqq->new_cfqq)) { | |
3082 | if (__cfqq == cfqq) | |
3083 | return; | |
3084 | new_cfqq = __cfqq; | |
3085 | } | |
3086 | ||
3087 | process_refs = cfqq_process_refs(cfqq); | |
3088 | new_process_refs = cfqq_process_refs(new_cfqq); | |
3089 | /* | |
3090 | * If the process for the cfqq has gone away, there is no | |
3091 | * sense in merging the queues. | |
3092 | */ | |
3093 | if (process_refs == 0 || new_process_refs == 0) | |
3094 | return; | |
3095 | ||
3096 | /* | |
3097 | * Merge in the direction of the lesser amount of work. | |
3098 | */ | |
3099 | if (new_process_refs >= process_refs) { | |
3100 | cfqq->new_cfqq = new_cfqq; | |
3101 | new_cfqq->ref += process_refs; | |
3102 | } else { | |
3103 | new_cfqq->new_cfqq = cfqq; | |
3104 | cfqq->ref += new_process_refs; | |
3105 | } | |
3106 | } | |
3107 | ||
3108 | static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd, | |
3109 | struct cfq_group *cfqg, enum wl_class_t wl_class) | |
3110 | { | |
3111 | struct cfq_queue *queue; | |
3112 | int i; | |
3113 | bool key_valid = false; | |
3114 | u64 lowest_key = 0; | |
3115 | enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; | |
3116 | ||
3117 | for (i = 0; i <= SYNC_WORKLOAD; ++i) { | |
3118 | /* select the one with lowest rb_key */ | |
3119 | queue = cfq_rb_first(st_for(cfqg, wl_class, i)); | |
3120 | if (queue && | |
3121 | (!key_valid || queue->rb_key < lowest_key)) { | |
3122 | lowest_key = queue->rb_key; | |
3123 | cur_best = i; | |
3124 | key_valid = true; | |
3125 | } | |
3126 | } | |
3127 | ||
3128 | return cur_best; | |
3129 | } | |
3130 | ||
3131 | static void | |
3132 | choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
3133 | { | |
3134 | u64 slice; | |
3135 | unsigned count; | |
3136 | struct cfq_rb_root *st; | |
3137 | u64 group_slice; | |
3138 | enum wl_class_t original_class = cfqd->serving_wl_class; | |
3139 | u64 now = ktime_get_ns(); | |
3140 | ||
3141 | /* Choose next priority. RT > BE > IDLE */ | |
3142 | if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) | |
3143 | cfqd->serving_wl_class = RT_WORKLOAD; | |
3144 | else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg)) | |
3145 | cfqd->serving_wl_class = BE_WORKLOAD; | |
3146 | else { | |
3147 | cfqd->serving_wl_class = IDLE_WORKLOAD; | |
3148 | cfqd->workload_expires = now + jiffies_to_nsecs(1); | |
3149 | return; | |
3150 | } | |
3151 | ||
3152 | if (original_class != cfqd->serving_wl_class) | |
3153 | goto new_workload; | |
3154 | ||
3155 | /* | |
3156 | * For RT and BE, we have to choose also the type | |
3157 | * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload | |
3158 | * expiration time | |
3159 | */ | |
3160 | st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type); | |
3161 | count = st->count; | |
3162 | ||
3163 | /* | |
3164 | * check workload expiration, and that we still have other queues ready | |
3165 | */ | |
3166 | if (count && !(now > cfqd->workload_expires)) | |
3167 | return; | |
3168 | ||
3169 | new_workload: | |
3170 | /* otherwise select new workload type */ | |
3171 | cfqd->serving_wl_type = cfq_choose_wl_type(cfqd, cfqg, | |
3172 | cfqd->serving_wl_class); | |
3173 | st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type); | |
3174 | count = st->count; | |
3175 | ||
3176 | /* | |
3177 | * the workload slice is computed as a fraction of target latency | |
3178 | * proportional to the number of queues in that workload, over | |
3179 | * all the queues in the same priority class | |
3180 | */ | |
3181 | group_slice = cfq_group_slice(cfqd, cfqg); | |
3182 | ||
3183 | slice = div_u64(group_slice * count, | |
3184 | max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_wl_class], | |
3185 | cfq_group_busy_queues_wl(cfqd->serving_wl_class, cfqd, | |
3186 | cfqg))); | |
3187 | ||
3188 | if (cfqd->serving_wl_type == ASYNC_WORKLOAD) { | |
3189 | u64 tmp; | |
3190 | ||
3191 | /* | |
3192 | * Async queues are currently system wide. Just taking | |
3193 | * proportion of queues with-in same group will lead to higher | |
3194 | * async ratio system wide as generally root group is going | |
3195 | * to have higher weight. A more accurate thing would be to | |
3196 | * calculate system wide asnc/sync ratio. | |
3197 | */ | |
3198 | tmp = cfqd->cfq_target_latency * | |
3199 | cfqg_busy_async_queues(cfqd, cfqg); | |
3200 | tmp = div_u64(tmp, cfqd->busy_queues); | |
3201 | slice = min_t(u64, slice, tmp); | |
3202 | ||
3203 | /* async workload slice is scaled down according to | |
3204 | * the sync/async slice ratio. */ | |
3205 | slice = div64_u64(slice*cfqd->cfq_slice[0], cfqd->cfq_slice[1]); | |
3206 | } else | |
3207 | /* sync workload slice is at least 2 * cfq_slice_idle */ | |
3208 | slice = max(slice, 2 * cfqd->cfq_slice_idle); | |
3209 | ||
3210 | slice = max_t(u64, slice, CFQ_MIN_TT); | |
3211 | cfq_log(cfqd, "workload slice:%llu", slice); | |
3212 | cfqd->workload_expires = now + slice; | |
3213 | } | |
3214 | ||
3215 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) | |
3216 | { | |
3217 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
3218 | struct cfq_group *cfqg; | |
3219 | ||
3220 | if (RB_EMPTY_ROOT(&st->rb)) | |
3221 | return NULL; | |
3222 | cfqg = cfq_rb_first_group(st); | |
3223 | update_min_vdisktime(st); | |
3224 | return cfqg; | |
3225 | } | |
3226 | ||
3227 | static void cfq_choose_cfqg(struct cfq_data *cfqd) | |
3228 | { | |
3229 | struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); | |
3230 | u64 now = ktime_get_ns(); | |
3231 | ||
3232 | cfqd->serving_group = cfqg; | |
3233 | ||
3234 | /* Restore the workload type data */ | |
3235 | if (cfqg->saved_wl_slice) { | |
3236 | cfqd->workload_expires = now + cfqg->saved_wl_slice; | |
3237 | cfqd->serving_wl_type = cfqg->saved_wl_type; | |
3238 | cfqd->serving_wl_class = cfqg->saved_wl_class; | |
3239 | } else | |
3240 | cfqd->workload_expires = now - 1; | |
3241 | ||
3242 | choose_wl_class_and_type(cfqd, cfqg); | |
3243 | } | |
3244 | ||
3245 | /* | |
3246 | * Select a queue for service. If we have a current active queue, | |
3247 | * check whether to continue servicing it, or retrieve and set a new one. | |
3248 | */ | |
3249 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) | |
3250 | { | |
3251 | struct cfq_queue *cfqq, *new_cfqq = NULL; | |
3252 | u64 now = ktime_get_ns(); | |
3253 | ||
3254 | cfqq = cfqd->active_queue; | |
3255 | if (!cfqq) | |
3256 | goto new_queue; | |
3257 | ||
3258 | if (!cfqd->rq_queued) | |
3259 | return NULL; | |
3260 | ||
3261 | /* | |
3262 | * We were waiting for group to get backlogged. Expire the queue | |
3263 | */ | |
3264 | if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list)) | |
3265 | goto expire; | |
3266 | ||
3267 | /* | |
3268 | * The active queue has run out of time, expire it and select new. | |
3269 | */ | |
3270 | if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) { | |
3271 | /* | |
3272 | * If slice had not expired at the completion of last request | |
3273 | * we might not have turned on wait_busy flag. Don't expire | |
3274 | * the queue yet. Allow the group to get backlogged. | |
3275 | * | |
3276 | * The very fact that we have used the slice, that means we | |
3277 | * have been idling all along on this queue and it should be | |
3278 | * ok to wait for this request to complete. | |
3279 | */ | |
3280 | if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list) | |
3281 | && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { | |
3282 | cfqq = NULL; | |
3283 | goto keep_queue; | |
3284 | } else | |
3285 | goto check_group_idle; | |
3286 | } | |
3287 | ||
3288 | /* | |
3289 | * The active queue has requests and isn't expired, allow it to | |
3290 | * dispatch. | |
3291 | */ | |
3292 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) | |
3293 | goto keep_queue; | |
3294 | ||
3295 | /* | |
3296 | * If another queue has a request waiting within our mean seek | |
3297 | * distance, let it run. The expire code will check for close | |
3298 | * cooperators and put the close queue at the front of the service | |
3299 | * tree. If possible, merge the expiring queue with the new cfqq. | |
3300 | */ | |
3301 | new_cfqq = cfq_close_cooperator(cfqd, cfqq); | |
3302 | if (new_cfqq) { | |
3303 | if (!cfqq->new_cfqq) | |
3304 | cfq_setup_merge(cfqq, new_cfqq); | |
3305 | goto expire; | |
3306 | } | |
3307 | ||
3308 | /* | |
3309 | * No requests pending. If the active queue still has requests in | |
3310 | * flight or is idling for a new request, allow either of these | |
3311 | * conditions to happen (or time out) before selecting a new queue. | |
3312 | */ | |
3313 | if (hrtimer_active(&cfqd->idle_slice_timer)) { | |
3314 | cfqq = NULL; | |
3315 | goto keep_queue; | |
3316 | } | |
3317 | ||
3318 | /* | |
3319 | * This is a deep seek queue, but the device is much faster than | |
3320 | * the queue can deliver, don't idle | |
3321 | **/ | |
3322 | if (CFQQ_SEEKY(cfqq) && cfq_cfqq_idle_window(cfqq) && | |
3323 | (cfq_cfqq_slice_new(cfqq) || | |
3324 | (cfqq->slice_end - now > now - cfqq->slice_start))) { | |
3325 | cfq_clear_cfqq_deep(cfqq); | |
3326 | cfq_clear_cfqq_idle_window(cfqq); | |
3327 | } | |
3328 | ||
3329 | if (cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { | |
3330 | cfqq = NULL; | |
3331 | goto keep_queue; | |
3332 | } | |
3333 | ||
3334 | /* | |
3335 | * If group idle is enabled and there are requests dispatched from | |
3336 | * this group, wait for requests to complete. | |
3337 | */ | |
3338 | check_group_idle: | |
3339 | if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1 && | |
3340 | cfqq->cfqg->dispatched && | |
3341 | !cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) { | |
3342 | cfqq = NULL; | |
3343 | goto keep_queue; | |
3344 | } | |
3345 | ||
3346 | expire: | |
3347 | cfq_slice_expired(cfqd, 0); | |
3348 | new_queue: | |
3349 | /* | |
3350 | * Current queue expired. Check if we have to switch to a new | |
3351 | * service tree | |
3352 | */ | |
3353 | if (!new_cfqq) | |
3354 | cfq_choose_cfqg(cfqd); | |
3355 | ||
3356 | cfqq = cfq_set_active_queue(cfqd, new_cfqq); | |
3357 | keep_queue: | |
3358 | return cfqq; | |
3359 | } | |
3360 | ||
3361 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) | |
3362 | { | |
3363 | int dispatched = 0; | |
3364 | ||
3365 | while (cfqq->next_rq) { | |
3366 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); | |
3367 | dispatched++; | |
3368 | } | |
3369 | ||
3370 | BUG_ON(!list_empty(&cfqq->fifo)); | |
3371 | ||
3372 | /* By default cfqq is not expired if it is empty. Do it explicitly */ | |
3373 | __cfq_slice_expired(cfqq->cfqd, cfqq, 0); | |
3374 | return dispatched; | |
3375 | } | |
3376 | ||
3377 | /* | |
3378 | * Drain our current requests. Used for barriers and when switching | |
3379 | * io schedulers on-the-fly. | |
3380 | */ | |
3381 | static int cfq_forced_dispatch(struct cfq_data *cfqd) | |
3382 | { | |
3383 | struct cfq_queue *cfqq; | |
3384 | int dispatched = 0; | |
3385 | ||
3386 | /* Expire the timeslice of the current active queue first */ | |
3387 | cfq_slice_expired(cfqd, 0); | |
3388 | while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) { | |
3389 | __cfq_set_active_queue(cfqd, cfqq); | |
3390 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); | |
3391 | } | |
3392 | ||
3393 | BUG_ON(cfqd->busy_queues); | |
3394 | ||
3395 | cfq_log(cfqd, "forced_dispatch=%d", dispatched); | |
3396 | return dispatched; | |
3397 | } | |
3398 | ||
3399 | static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, | |
3400 | struct cfq_queue *cfqq) | |
3401 | { | |
3402 | u64 now = ktime_get_ns(); | |
3403 | ||
3404 | /* the queue hasn't finished any request, can't estimate */ | |
3405 | if (cfq_cfqq_slice_new(cfqq)) | |
3406 | return true; | |
3407 | if (now + cfqd->cfq_slice_idle * cfqq->dispatched > cfqq->slice_end) | |
3408 | return true; | |
3409 | ||
3410 | return false; | |
3411 | } | |
3412 | ||
3413 | static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3414 | { | |
3415 | unsigned int max_dispatch; | |
3416 | ||
3417 | if (cfq_cfqq_must_dispatch(cfqq)) | |
3418 | return true; | |
3419 | ||
3420 | /* | |
3421 | * Drain async requests before we start sync IO | |
3422 | */ | |
3423 | if (cfq_should_idle(cfqd, cfqq) && cfqd->rq_in_flight[BLK_RW_ASYNC]) | |
3424 | return false; | |
3425 | ||
3426 | /* | |
3427 | * If this is an async queue and we have sync IO in flight, let it wait | |
3428 | */ | |
3429 | if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq)) | |
3430 | return false; | |
3431 | ||
3432 | max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1); | |
3433 | if (cfq_class_idle(cfqq)) | |
3434 | max_dispatch = 1; | |
3435 | ||
3436 | /* | |
3437 | * Does this cfqq already have too much IO in flight? | |
3438 | */ | |
3439 | if (cfqq->dispatched >= max_dispatch) { | |
3440 | bool promote_sync = false; | |
3441 | /* | |
3442 | * idle queue must always only have a single IO in flight | |
3443 | */ | |
3444 | if (cfq_class_idle(cfqq)) | |
3445 | return false; | |
3446 | ||
3447 | /* | |
3448 | * If there is only one sync queue | |
3449 | * we can ignore async queue here and give the sync | |
3450 | * queue no dispatch limit. The reason is a sync queue can | |
3451 | * preempt async queue, limiting the sync queue doesn't make | |
3452 | * sense. This is useful for aiostress test. | |
3453 | */ | |
3454 | if (cfq_cfqq_sync(cfqq) && cfqd->busy_sync_queues == 1) | |
3455 | promote_sync = true; | |
3456 | ||
3457 | /* | |
3458 | * We have other queues, don't allow more IO from this one | |
3459 | */ | |
3460 | if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq) && | |
3461 | !promote_sync) | |
3462 | return false; | |
3463 | ||
3464 | /* | |
3465 | * Sole queue user, no limit | |
3466 | */ | |
3467 | if (cfqd->busy_queues == 1 || promote_sync) | |
3468 | max_dispatch = -1; | |
3469 | else | |
3470 | /* | |
3471 | * Normally we start throttling cfqq when cfq_quantum/2 | |
3472 | * requests have been dispatched. But we can drive | |
3473 | * deeper queue depths at the beginning of slice | |
3474 | * subjected to upper limit of cfq_quantum. | |
3475 | * */ | |
3476 | max_dispatch = cfqd->cfq_quantum; | |
3477 | } | |
3478 | ||
3479 | /* | |
3480 | * Async queues must wait a bit before being allowed dispatch. | |
3481 | * We also ramp up the dispatch depth gradually for async IO, | |
3482 | * based on the last sync IO we serviced | |
3483 | */ | |
3484 | if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { | |
3485 | u64 last_sync = ktime_get_ns() - cfqd->last_delayed_sync; | |
3486 | unsigned int depth; | |
3487 | ||
3488 | depth = div64_u64(last_sync, cfqd->cfq_slice[1]); | |
3489 | if (!depth && !cfqq->dispatched) | |
3490 | depth = 1; | |
3491 | if (depth < max_dispatch) | |
3492 | max_dispatch = depth; | |
3493 | } | |
3494 | ||
3495 | /* | |
3496 | * If we're below the current max, allow a dispatch | |
3497 | */ | |
3498 | return cfqq->dispatched < max_dispatch; | |
3499 | } | |
3500 | ||
3501 | /* | |
3502 | * Dispatch a request from cfqq, moving them to the request queue | |
3503 | * dispatch list. | |
3504 | */ | |
3505 | static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3506 | { | |
3507 | struct request *rq; | |
3508 | ||
3509 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); | |
3510 | ||
3511 | rq = cfq_check_fifo(cfqq); | |
3512 | if (rq) | |
3513 | cfq_mark_cfqq_must_dispatch(cfqq); | |
3514 | ||
3515 | if (!cfq_may_dispatch(cfqd, cfqq)) | |
3516 | return false; | |
3517 | ||
3518 | /* | |
3519 | * follow expired path, else get first next available | |
3520 | */ | |
3521 | if (!rq) | |
3522 | rq = cfqq->next_rq; | |
3523 | else | |
3524 | cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); | |
3525 | ||
3526 | /* | |
3527 | * insert request into driver dispatch list | |
3528 | */ | |
3529 | cfq_dispatch_insert(cfqd->queue, rq); | |
3530 | ||
3531 | if (!cfqd->active_cic) { | |
3532 | struct cfq_io_cq *cic = RQ_CIC(rq); | |
3533 | ||
3534 | atomic_long_inc(&cic->icq.ioc->refcount); | |
3535 | cfqd->active_cic = cic; | |
3536 | } | |
3537 | ||
3538 | return true; | |
3539 | } | |
3540 | ||
3541 | /* | |
3542 | * Find the cfqq that we need to service and move a request from that to the | |
3543 | * dispatch list | |
3544 | */ | |
3545 | static int cfq_dispatch_requests(struct request_queue *q, int force) | |
3546 | { | |
3547 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
3548 | struct cfq_queue *cfqq; | |
3549 | ||
3550 | if (!cfqd->busy_queues) | |
3551 | return 0; | |
3552 | ||
3553 | if (unlikely(force)) | |
3554 | return cfq_forced_dispatch(cfqd); | |
3555 | ||
3556 | cfqq = cfq_select_queue(cfqd); | |
3557 | if (!cfqq) | |
3558 | return 0; | |
3559 | ||
3560 | /* | |
3561 | * Dispatch a request from this cfqq, if it is allowed | |
3562 | */ | |
3563 | if (!cfq_dispatch_request(cfqd, cfqq)) | |
3564 | return 0; | |
3565 | ||
3566 | cfqq->slice_dispatch++; | |
3567 | cfq_clear_cfqq_must_dispatch(cfqq); | |
3568 | ||
3569 | /* | |
3570 | * expire an async queue immediately if it has used up its slice. idle | |
3571 | * queue always expire after 1 dispatch round. | |
3572 | */ | |
3573 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && | |
3574 | cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || | |
3575 | cfq_class_idle(cfqq))) { | |
3576 | cfqq->slice_end = ktime_get_ns() + 1; | |
3577 | cfq_slice_expired(cfqd, 0); | |
3578 | } | |
3579 | ||
3580 | cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); | |
3581 | return 1; | |
3582 | } | |
3583 | ||
3584 | /* | |
3585 | * task holds one reference to the queue, dropped when task exits. each rq | |
3586 | * in-flight on this queue also holds a reference, dropped when rq is freed. | |
3587 | * | |
3588 | * Each cfq queue took a reference on the parent group. Drop it now. | |
3589 | * queue lock must be held here. | |
3590 | */ | |
3591 | static void cfq_put_queue(struct cfq_queue *cfqq) | |
3592 | { | |
3593 | struct cfq_data *cfqd = cfqq->cfqd; | |
3594 | struct cfq_group *cfqg; | |
3595 | ||
3596 | BUG_ON(cfqq->ref <= 0); | |
3597 | ||
3598 | cfqq->ref--; | |
3599 | if (cfqq->ref) | |
3600 | return; | |
3601 | ||
3602 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); | |
3603 | BUG_ON(rb_first(&cfqq->sort_list)); | |
3604 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); | |
3605 | cfqg = cfqq->cfqg; | |
3606 | ||
3607 | if (unlikely(cfqd->active_queue == cfqq)) { | |
3608 | __cfq_slice_expired(cfqd, cfqq, 0); | |
3609 | cfq_schedule_dispatch(cfqd); | |
3610 | } | |
3611 | ||
3612 | BUG_ON(cfq_cfqq_on_rr(cfqq)); | |
3613 | kmem_cache_free(cfq_pool, cfqq); | |
3614 | cfqg_put(cfqg); | |
3615 | } | |
3616 | ||
3617 | static void cfq_put_cooperator(struct cfq_queue *cfqq) | |
3618 | { | |
3619 | struct cfq_queue *__cfqq, *next; | |
3620 | ||
3621 | /* | |
3622 | * If this queue was scheduled to merge with another queue, be | |
3623 | * sure to drop the reference taken on that queue (and others in | |
3624 | * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. | |
3625 | */ | |
3626 | __cfqq = cfqq->new_cfqq; | |
3627 | while (__cfqq) { | |
3628 | if (__cfqq == cfqq) { | |
3629 | WARN(1, "cfqq->new_cfqq loop detected\n"); | |
3630 | break; | |
3631 | } | |
3632 | next = __cfqq->new_cfqq; | |
3633 | cfq_put_queue(__cfqq); | |
3634 | __cfqq = next; | |
3635 | } | |
3636 | } | |
3637 | ||
3638 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3639 | { | |
3640 | if (unlikely(cfqq == cfqd->active_queue)) { | |
3641 | __cfq_slice_expired(cfqd, cfqq, 0); | |
3642 | cfq_schedule_dispatch(cfqd); | |
3643 | } | |
3644 | ||
3645 | cfq_put_cooperator(cfqq); | |
3646 | ||
3647 | cfq_put_queue(cfqq); | |
3648 | } | |
3649 | ||
3650 | static void cfq_init_icq(struct io_cq *icq) | |
3651 | { | |
3652 | struct cfq_io_cq *cic = icq_to_cic(icq); | |
3653 | ||
3654 | cic->ttime.last_end_request = ktime_get_ns(); | |
3655 | } | |
3656 | ||
3657 | static void cfq_exit_icq(struct io_cq *icq) | |
3658 | { | |
3659 | struct cfq_io_cq *cic = icq_to_cic(icq); | |
3660 | struct cfq_data *cfqd = cic_to_cfqd(cic); | |
3661 | ||
3662 | if (cic_to_cfqq(cic, false)) { | |
3663 | cfq_exit_cfqq(cfqd, cic_to_cfqq(cic, false)); | |
3664 | cic_set_cfqq(cic, NULL, false); | |
3665 | } | |
3666 | ||
3667 | if (cic_to_cfqq(cic, true)) { | |
3668 | cfq_exit_cfqq(cfqd, cic_to_cfqq(cic, true)); | |
3669 | cic_set_cfqq(cic, NULL, true); | |
3670 | } | |
3671 | } | |
3672 | ||
3673 | static void cfq_init_prio_data(struct cfq_queue *cfqq, struct cfq_io_cq *cic) | |
3674 | { | |
3675 | struct task_struct *tsk = current; | |
3676 | int ioprio_class; | |
3677 | ||
3678 | if (!cfq_cfqq_prio_changed(cfqq)) | |
3679 | return; | |
3680 | ||
3681 | ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio); | |
3682 | switch (ioprio_class) { | |
3683 | default: | |
3684 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); | |
3685 | case IOPRIO_CLASS_NONE: | |
3686 | /* | |
3687 | * no prio set, inherit CPU scheduling settings | |
3688 | */ | |
3689 | cfqq->ioprio = task_nice_ioprio(tsk); | |
3690 | cfqq->ioprio_class = task_nice_ioclass(tsk); | |
3691 | break; | |
3692 | case IOPRIO_CLASS_RT: | |
3693 | cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio); | |
3694 | cfqq->ioprio_class = IOPRIO_CLASS_RT; | |
3695 | break; | |
3696 | case IOPRIO_CLASS_BE: | |
3697 | cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio); | |
3698 | cfqq->ioprio_class = IOPRIO_CLASS_BE; | |
3699 | break; | |
3700 | case IOPRIO_CLASS_IDLE: | |
3701 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; | |
3702 | cfqq->ioprio = 7; | |
3703 | cfq_clear_cfqq_idle_window(cfqq); | |
3704 | break; | |
3705 | } | |
3706 | ||
3707 | /* | |
3708 | * keep track of original prio settings in case we have to temporarily | |
3709 | * elevate the priority of this queue | |
3710 | */ | |
3711 | cfqq->org_ioprio = cfqq->ioprio; | |
3712 | cfqq->org_ioprio_class = cfqq->ioprio_class; | |
3713 | cfq_clear_cfqq_prio_changed(cfqq); | |
3714 | } | |
3715 | ||
3716 | static void check_ioprio_changed(struct cfq_io_cq *cic, struct bio *bio) | |
3717 | { | |
3718 | int ioprio = cic->icq.ioc->ioprio; | |
3719 | struct cfq_data *cfqd = cic_to_cfqd(cic); | |
3720 | struct cfq_queue *cfqq; | |
3721 | ||
3722 | /* | |
3723 | * Check whether ioprio has changed. The condition may trigger | |
3724 | * spuriously on a newly created cic but there's no harm. | |
3725 | */ | |
3726 | if (unlikely(!cfqd) || likely(cic->ioprio == ioprio)) | |
3727 | return; | |
3728 | ||
3729 | cfqq = cic_to_cfqq(cic, false); | |
3730 | if (cfqq) { | |
3731 | cfq_put_queue(cfqq); | |
3732 | cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic, bio); | |
3733 | cic_set_cfqq(cic, cfqq, false); | |
3734 | } | |
3735 | ||
3736 | cfqq = cic_to_cfqq(cic, true); | |
3737 | if (cfqq) | |
3738 | cfq_mark_cfqq_prio_changed(cfqq); | |
3739 | ||
3740 | cic->ioprio = ioprio; | |
3741 | } | |
3742 | ||
3743 | static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
3744 | pid_t pid, bool is_sync) | |
3745 | { | |
3746 | RB_CLEAR_NODE(&cfqq->rb_node); | |
3747 | RB_CLEAR_NODE(&cfqq->p_node); | |
3748 | INIT_LIST_HEAD(&cfqq->fifo); | |
3749 | ||
3750 | cfqq->ref = 0; | |
3751 | cfqq->cfqd = cfqd; | |
3752 | ||
3753 | cfq_mark_cfqq_prio_changed(cfqq); | |
3754 | ||
3755 | if (is_sync) { | |
3756 | if (!cfq_class_idle(cfqq)) | |
3757 | cfq_mark_cfqq_idle_window(cfqq); | |
3758 | cfq_mark_cfqq_sync(cfqq); | |
3759 | } | |
3760 | cfqq->pid = pid; | |
3761 | } | |
3762 | ||
3763 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
3764 | static bool check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) | |
3765 | { | |
3766 | struct cfq_data *cfqd = cic_to_cfqd(cic); | |
3767 | struct cfq_queue *cfqq; | |
3768 | uint64_t serial_nr; | |
3769 | bool nonroot_cg; | |
3770 | ||
3771 | rcu_read_lock(); | |
3772 | serial_nr = bio_blkcg(bio)->css.serial_nr; | |
3773 | nonroot_cg = bio_blkcg(bio) != &blkcg_root; | |
3774 | rcu_read_unlock(); | |
3775 | ||
3776 | /* | |
3777 | * Check whether blkcg has changed. The condition may trigger | |
3778 | * spuriously on a newly created cic but there's no harm. | |
3779 | */ | |
3780 | if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr)) | |
3781 | return nonroot_cg; | |
3782 | ||
3783 | /* | |
3784 | * Drop reference to queues. New queues will be assigned in new | |
3785 | * group upon arrival of fresh requests. | |
3786 | */ | |
3787 | cfqq = cic_to_cfqq(cic, false); | |
3788 | if (cfqq) { | |
3789 | cfq_log_cfqq(cfqd, cfqq, "changed cgroup"); | |
3790 | cic_set_cfqq(cic, NULL, false); | |
3791 | cfq_put_queue(cfqq); | |
3792 | } | |
3793 | ||
3794 | cfqq = cic_to_cfqq(cic, true); | |
3795 | if (cfqq) { | |
3796 | cfq_log_cfqq(cfqd, cfqq, "changed cgroup"); | |
3797 | cic_set_cfqq(cic, NULL, true); | |
3798 | cfq_put_queue(cfqq); | |
3799 | } | |
3800 | ||
3801 | cic->blkcg_serial_nr = serial_nr; | |
3802 | return nonroot_cg; | |
3803 | } | |
3804 | #else | |
3805 | static inline bool check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) | |
3806 | { | |
3807 | return false; | |
3808 | } | |
3809 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ | |
3810 | ||
3811 | static struct cfq_queue ** | |
3812 | cfq_async_queue_prio(struct cfq_group *cfqg, int ioprio_class, int ioprio) | |
3813 | { | |
3814 | switch (ioprio_class) { | |
3815 | case IOPRIO_CLASS_RT: | |
3816 | return &cfqg->async_cfqq[0][ioprio]; | |
3817 | case IOPRIO_CLASS_NONE: | |
3818 | ioprio = IOPRIO_NORM; | |
3819 | /* fall through */ | |
3820 | case IOPRIO_CLASS_BE: | |
3821 | return &cfqg->async_cfqq[1][ioprio]; | |
3822 | case IOPRIO_CLASS_IDLE: | |
3823 | return &cfqg->async_idle_cfqq; | |
3824 | default: | |
3825 | BUG(); | |
3826 | } | |
3827 | } | |
3828 | ||
3829 | static struct cfq_queue * | |
3830 | cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, | |
3831 | struct bio *bio) | |
3832 | { | |
3833 | int ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio); | |
3834 | int ioprio = IOPRIO_PRIO_DATA(cic->ioprio); | |
3835 | struct cfq_queue **async_cfqq = NULL; | |
3836 | struct cfq_queue *cfqq; | |
3837 | struct cfq_group *cfqg; | |
3838 | ||
3839 | rcu_read_lock(); | |
3840 | cfqg = cfq_lookup_cfqg(cfqd, bio_blkcg(bio)); | |
3841 | if (!cfqg) { | |
3842 | cfqq = &cfqd->oom_cfqq; | |
3843 | goto out; | |
3844 | } | |
3845 | ||
3846 | if (!is_sync) { | |
3847 | if (!ioprio_valid(cic->ioprio)) { | |
3848 | struct task_struct *tsk = current; | |
3849 | ioprio = task_nice_ioprio(tsk); | |
3850 | ioprio_class = task_nice_ioclass(tsk); | |
3851 | } | |
3852 | async_cfqq = cfq_async_queue_prio(cfqg, ioprio_class, ioprio); | |
3853 | cfqq = *async_cfqq; | |
3854 | if (cfqq) | |
3855 | goto out; | |
3856 | } | |
3857 | ||
3858 | cfqq = kmem_cache_alloc_node(cfq_pool, | |
3859 | GFP_NOWAIT | __GFP_ZERO | __GFP_NOWARN, | |
3860 | cfqd->queue->node); | |
3861 | if (!cfqq) { | |
3862 | cfqq = &cfqd->oom_cfqq; | |
3863 | goto out; | |
3864 | } | |
3865 | ||
3866 | /* cfq_init_cfqq() assumes cfqq->ioprio_class is initialized. */ | |
3867 | cfqq->ioprio_class = IOPRIO_CLASS_NONE; | |
3868 | cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); | |
3869 | cfq_init_prio_data(cfqq, cic); | |
3870 | cfq_link_cfqq_cfqg(cfqq, cfqg); | |
3871 | cfq_log_cfqq(cfqd, cfqq, "alloced"); | |
3872 | ||
3873 | if (async_cfqq) { | |
3874 | /* a new async queue is created, pin and remember */ | |
3875 | cfqq->ref++; | |
3876 | *async_cfqq = cfqq; | |
3877 | } | |
3878 | out: | |
3879 | cfqq->ref++; | |
3880 | rcu_read_unlock(); | |
3881 | return cfqq; | |
3882 | } | |
3883 | ||
3884 | static void | |
3885 | __cfq_update_io_thinktime(struct cfq_ttime *ttime, u64 slice_idle) | |
3886 | { | |
3887 | u64 elapsed = ktime_get_ns() - ttime->last_end_request; | |
3888 | elapsed = min(elapsed, 2UL * slice_idle); | |
3889 | ||
3890 | ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8; | |
3891 | ttime->ttime_total = div_u64(7*ttime->ttime_total + 256*elapsed, 8); | |
3892 | ttime->ttime_mean = div64_ul(ttime->ttime_total + 128, | |
3893 | ttime->ttime_samples); | |
3894 | } | |
3895 | ||
3896 | static void | |
3897 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
3898 | struct cfq_io_cq *cic) | |
3899 | { | |
3900 | if (cfq_cfqq_sync(cfqq)) { | |
3901 | __cfq_update_io_thinktime(&cic->ttime, cfqd->cfq_slice_idle); | |
3902 | __cfq_update_io_thinktime(&cfqq->service_tree->ttime, | |
3903 | cfqd->cfq_slice_idle); | |
3904 | } | |
3905 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
3906 | __cfq_update_io_thinktime(&cfqq->cfqg->ttime, cfqd->cfq_group_idle); | |
3907 | #endif | |
3908 | } | |
3909 | ||
3910 | static void | |
3911 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
3912 | struct request *rq) | |
3913 | { | |
3914 | sector_t sdist = 0; | |
3915 | sector_t n_sec = blk_rq_sectors(rq); | |
3916 | if (cfqq->last_request_pos) { | |
3917 | if (cfqq->last_request_pos < blk_rq_pos(rq)) | |
3918 | sdist = blk_rq_pos(rq) - cfqq->last_request_pos; | |
3919 | else | |
3920 | sdist = cfqq->last_request_pos - blk_rq_pos(rq); | |
3921 | } | |
3922 | ||
3923 | cfqq->seek_history <<= 1; | |
3924 | if (blk_queue_nonrot(cfqd->queue)) | |
3925 | cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT); | |
3926 | else | |
3927 | cfqq->seek_history |= (sdist > CFQQ_SEEK_THR); | |
3928 | } | |
3929 | ||
3930 | static inline bool req_noidle(struct request *req) | |
3931 | { | |
3932 | return req_op(req) == REQ_OP_WRITE && | |
3933 | (req->cmd_flags & (REQ_SYNC | REQ_IDLE)) == REQ_SYNC; | |
3934 | } | |
3935 | ||
3936 | /* | |
3937 | * Disable idle window if the process thinks too long or seeks so much that | |
3938 | * it doesn't matter | |
3939 | */ | |
3940 | static void | |
3941 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
3942 | struct cfq_io_cq *cic) | |
3943 | { | |
3944 | int old_idle, enable_idle; | |
3945 | ||
3946 | /* | |
3947 | * Don't idle for async or idle io prio class | |
3948 | */ | |
3949 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) | |
3950 | return; | |
3951 | ||
3952 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); | |
3953 | ||
3954 | if (cfqq->queued[0] + cfqq->queued[1] >= 4) | |
3955 | cfq_mark_cfqq_deep(cfqq); | |
3956 | ||
3957 | if (cfqq->next_rq && req_noidle(cfqq->next_rq)) | |
3958 | enable_idle = 0; | |
3959 | else if (!atomic_read(&cic->icq.ioc->active_ref) || | |
3960 | !cfqd->cfq_slice_idle || | |
3961 | (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq))) | |
3962 | enable_idle = 0; | |
3963 | else if (sample_valid(cic->ttime.ttime_samples)) { | |
3964 | if (cic->ttime.ttime_mean > cfqd->cfq_slice_idle) | |
3965 | enable_idle = 0; | |
3966 | else | |
3967 | enable_idle = 1; | |
3968 | } | |
3969 | ||
3970 | if (old_idle != enable_idle) { | |
3971 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); | |
3972 | if (enable_idle) | |
3973 | cfq_mark_cfqq_idle_window(cfqq); | |
3974 | else | |
3975 | cfq_clear_cfqq_idle_window(cfqq); | |
3976 | } | |
3977 | } | |
3978 | ||
3979 | /* | |
3980 | * Check if new_cfqq should preempt the currently active queue. Return 0 for | |
3981 | * no or if we aren't sure, a 1 will cause a preempt. | |
3982 | */ | |
3983 | static bool | |
3984 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, | |
3985 | struct request *rq) | |
3986 | { | |
3987 | struct cfq_queue *cfqq; | |
3988 | ||
3989 | cfqq = cfqd->active_queue; | |
3990 | if (!cfqq) | |
3991 | return false; | |
3992 | ||
3993 | if (cfq_class_idle(new_cfqq)) | |
3994 | return false; | |
3995 | ||
3996 | if (cfq_class_idle(cfqq)) | |
3997 | return true; | |
3998 | ||
3999 | /* | |
4000 | * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice. | |
4001 | */ | |
4002 | if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq)) | |
4003 | return false; | |
4004 | ||
4005 | /* | |
4006 | * if the new request is sync, but the currently running queue is | |
4007 | * not, let the sync request have priority. | |
4008 | */ | |
4009 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) | |
4010 | return true; | |
4011 | ||
4012 | /* | |
4013 | * Treat ancestors of current cgroup the same way as current cgroup. | |
4014 | * For anybody else we disallow preemption to guarantee service | |
4015 | * fairness among cgroups. | |
4016 | */ | |
4017 | if (!cfqg_is_descendant(cfqq->cfqg, new_cfqq->cfqg)) | |
4018 | return false; | |
4019 | ||
4020 | if (cfq_slice_used(cfqq)) | |
4021 | return true; | |
4022 | ||
4023 | /* | |
4024 | * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. | |
4025 | */ | |
4026 | if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) | |
4027 | return true; | |
4028 | ||
4029 | WARN_ON_ONCE(cfqq->ioprio_class != new_cfqq->ioprio_class); | |
4030 | /* Allow preemption only if we are idling on sync-noidle tree */ | |
4031 | if (cfqd->serving_wl_type == SYNC_NOIDLE_WORKLOAD && | |
4032 | cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD && | |
4033 | RB_EMPTY_ROOT(&cfqq->sort_list)) | |
4034 | return true; | |
4035 | ||
4036 | /* | |
4037 | * So both queues are sync. Let the new request get disk time if | |
4038 | * it's a metadata request and the current queue is doing regular IO. | |
4039 | */ | |
4040 | if ((rq->cmd_flags & REQ_PRIO) && !cfqq->prio_pending) | |
4041 | return true; | |
4042 | ||
4043 | /* An idle queue should not be idle now for some reason */ | |
4044 | if (RB_EMPTY_ROOT(&cfqq->sort_list) && !cfq_should_idle(cfqd, cfqq)) | |
4045 | return true; | |
4046 | ||
4047 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) | |
4048 | return false; | |
4049 | ||
4050 | /* | |
4051 | * if this request is as-good as one we would expect from the | |
4052 | * current cfqq, let it preempt | |
4053 | */ | |
4054 | if (cfq_rq_close(cfqd, cfqq, rq)) | |
4055 | return true; | |
4056 | ||
4057 | return false; | |
4058 | } | |
4059 | ||
4060 | /* | |
4061 | * cfqq preempts the active queue. if we allowed preempt with no slice left, | |
4062 | * let it have half of its nominal slice. | |
4063 | */ | |
4064 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
4065 | { | |
4066 | enum wl_type_t old_type = cfqq_type(cfqd->active_queue); | |
4067 | ||
4068 | cfq_log_cfqq(cfqd, cfqq, "preempt"); | |
4069 | cfq_slice_expired(cfqd, 1); | |
4070 | ||
4071 | /* | |
4072 | * workload type is changed, don't save slice, otherwise preempt | |
4073 | * doesn't happen | |
4074 | */ | |
4075 | if (old_type != cfqq_type(cfqq)) | |
4076 | cfqq->cfqg->saved_wl_slice = 0; | |
4077 | ||
4078 | /* | |
4079 | * Put the new queue at the front of the of the current list, | |
4080 | * so we know that it will be selected next. | |
4081 | */ | |
4082 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); | |
4083 | ||
4084 | cfq_service_tree_add(cfqd, cfqq, 1); | |
4085 | ||
4086 | cfqq->slice_end = 0; | |
4087 | cfq_mark_cfqq_slice_new(cfqq); | |
4088 | } | |
4089 | ||
4090 | /* | |
4091 | * Called when a new fs request (rq) is added (to cfqq). Check if there's | |
4092 | * something we should do about it | |
4093 | */ | |
4094 | static void | |
4095 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
4096 | struct request *rq) | |
4097 | { | |
4098 | struct cfq_io_cq *cic = RQ_CIC(rq); | |
4099 | ||
4100 | cfqd->rq_queued++; | |
4101 | if (rq->cmd_flags & REQ_PRIO) | |
4102 | cfqq->prio_pending++; | |
4103 | ||
4104 | cfq_update_io_thinktime(cfqd, cfqq, cic); | |
4105 | cfq_update_io_seektime(cfqd, cfqq, rq); | |
4106 | cfq_update_idle_window(cfqd, cfqq, cic); | |
4107 | ||
4108 | cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); | |
4109 | ||
4110 | if (cfqq == cfqd->active_queue) { | |
4111 | /* | |
4112 | * Remember that we saw a request from this process, but | |
4113 | * don't start queuing just yet. Otherwise we risk seeing lots | |
4114 | * of tiny requests, because we disrupt the normal plugging | |
4115 | * and merging. If the request is already larger than a single | |
4116 | * page, let it rip immediately. For that case we assume that | |
4117 | * merging is already done. Ditto for a busy system that | |
4118 | * has other work pending, don't risk delaying until the | |
4119 | * idle timer unplug to continue working. | |
4120 | */ | |
4121 | if (cfq_cfqq_wait_request(cfqq)) { | |
4122 | if (blk_rq_bytes(rq) > PAGE_SIZE || | |
4123 | cfqd->busy_queues > 1) { | |
4124 | cfq_del_timer(cfqd, cfqq); | |
4125 | cfq_clear_cfqq_wait_request(cfqq); | |
4126 | __blk_run_queue(cfqd->queue); | |
4127 | } else { | |
4128 | cfqg_stats_update_idle_time(cfqq->cfqg); | |
4129 | cfq_mark_cfqq_must_dispatch(cfqq); | |
4130 | } | |
4131 | } | |
4132 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { | |
4133 | /* | |
4134 | * not the active queue - expire current slice if it is | |
4135 | * idle and has expired it's mean thinktime or this new queue | |
4136 | * has some old slice time left and is of higher priority or | |
4137 | * this new queue is RT and the current one is BE | |
4138 | */ | |
4139 | cfq_preempt_queue(cfqd, cfqq); | |
4140 | __blk_run_queue(cfqd->queue); | |
4141 | } | |
4142 | } | |
4143 | ||
4144 | static void cfq_insert_request(struct request_queue *q, struct request *rq) | |
4145 | { | |
4146 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
4147 | struct cfq_queue *cfqq = RQ_CFQQ(rq); | |
4148 | ||
4149 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); | |
4150 | cfq_init_prio_data(cfqq, RQ_CIC(rq)); | |
4151 | ||
4152 | rq->fifo_time = ktime_get_ns() + cfqd->cfq_fifo_expire[rq_is_sync(rq)]; | |
4153 | list_add_tail(&rq->queuelist, &cfqq->fifo); | |
4154 | cfq_add_rq_rb(rq); | |
4155 | cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group, | |
4156 | rq->cmd_flags); | |
4157 | cfq_rq_enqueued(cfqd, cfqq, rq); | |
4158 | } | |
4159 | ||
4160 | /* | |
4161 | * Update hw_tag based on peak queue depth over 50 samples under | |
4162 | * sufficient load. | |
4163 | */ | |
4164 | static void cfq_update_hw_tag(struct cfq_data *cfqd) | |
4165 | { | |
4166 | struct cfq_queue *cfqq = cfqd->active_queue; | |
4167 | ||
4168 | if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth) | |
4169 | cfqd->hw_tag_est_depth = cfqd->rq_in_driver; | |
4170 | ||
4171 | if (cfqd->hw_tag == 1) | |
4172 | return; | |
4173 | ||
4174 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && | |
4175 | cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN) | |
4176 | return; | |
4177 | ||
4178 | /* | |
4179 | * If active queue hasn't enough requests and can idle, cfq might not | |
4180 | * dispatch sufficient requests to hardware. Don't zero hw_tag in this | |
4181 | * case | |
4182 | */ | |
4183 | if (cfqq && cfq_cfqq_idle_window(cfqq) && | |
4184 | cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] < | |
4185 | CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN) | |
4186 | return; | |
4187 | ||
4188 | if (cfqd->hw_tag_samples++ < 50) | |
4189 | return; | |
4190 | ||
4191 | if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN) | |
4192 | cfqd->hw_tag = 1; | |
4193 | else | |
4194 | cfqd->hw_tag = 0; | |
4195 | } | |
4196 | ||
4197 | static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
4198 | { | |
4199 | struct cfq_io_cq *cic = cfqd->active_cic; | |
4200 | u64 now = ktime_get_ns(); | |
4201 | ||
4202 | /* If the queue already has requests, don't wait */ | |
4203 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) | |
4204 | return false; | |
4205 | ||
4206 | /* If there are other queues in the group, don't wait */ | |
4207 | if (cfqq->cfqg->nr_cfqq > 1) | |
4208 | return false; | |
4209 | ||
4210 | /* the only queue in the group, but think time is big */ | |
4211 | if (cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) | |
4212 | return false; | |
4213 | ||
4214 | if (cfq_slice_used(cfqq)) | |
4215 | return true; | |
4216 | ||
4217 | /* if slice left is less than think time, wait busy */ | |
4218 | if (cic && sample_valid(cic->ttime.ttime_samples) | |
4219 | && (cfqq->slice_end - now < cic->ttime.ttime_mean)) | |
4220 | return true; | |
4221 | ||
4222 | /* | |
4223 | * If think times is less than a jiffy than ttime_mean=0 and above | |
4224 | * will not be true. It might happen that slice has not expired yet | |
4225 | * but will expire soon (4-5 ns) during select_queue(). To cover the | |
4226 | * case where think time is less than a jiffy, mark the queue wait | |
4227 | * busy if only 1 jiffy is left in the slice. | |
4228 | */ | |
4229 | if (cfqq->slice_end - now <= jiffies_to_nsecs(1)) | |
4230 | return true; | |
4231 | ||
4232 | return false; | |
4233 | } | |
4234 | ||
4235 | static void cfq_completed_request(struct request_queue *q, struct request *rq) | |
4236 | { | |
4237 | struct cfq_queue *cfqq = RQ_CFQQ(rq); | |
4238 | struct cfq_data *cfqd = cfqq->cfqd; | |
4239 | const int sync = rq_is_sync(rq); | |
4240 | u64 now = ktime_get_ns(); | |
4241 | ||
4242 | cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", req_noidle(rq)); | |
4243 | ||
4244 | cfq_update_hw_tag(cfqd); | |
4245 | ||
4246 | WARN_ON(!cfqd->rq_in_driver); | |
4247 | WARN_ON(!cfqq->dispatched); | |
4248 | cfqd->rq_in_driver--; | |
4249 | cfqq->dispatched--; | |
4250 | (RQ_CFQG(rq))->dispatched--; | |
4251 | cfqg_stats_update_completion(cfqq->cfqg, rq_start_time_ns(rq), | |
4252 | rq_io_start_time_ns(rq), rq->cmd_flags); | |
4253 | ||
4254 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--; | |
4255 | ||
4256 | if (sync) { | |
4257 | struct cfq_rb_root *st; | |
4258 | ||
4259 | RQ_CIC(rq)->ttime.last_end_request = now; | |
4260 | ||
4261 | if (cfq_cfqq_on_rr(cfqq)) | |
4262 | st = cfqq->service_tree; | |
4263 | else | |
4264 | st = st_for(cfqq->cfqg, cfqq_class(cfqq), | |
4265 | cfqq_type(cfqq)); | |
4266 | ||
4267 | st->ttime.last_end_request = now; | |
4268 | /* | |
4269 | * We have to do this check in jiffies since start_time is in | |
4270 | * jiffies and it is not trivial to convert to ns. If | |
4271 | * cfq_fifo_expire[1] ever comes close to 1 jiffie, this test | |
4272 | * will become problematic but so far we are fine (the default | |
4273 | * is 128 ms). | |
4274 | */ | |
4275 | if (!time_after(rq->start_time + | |
4276 | nsecs_to_jiffies(cfqd->cfq_fifo_expire[1]), | |
4277 | jiffies)) | |
4278 | cfqd->last_delayed_sync = now; | |
4279 | } | |
4280 | ||
4281 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
4282 | cfqq->cfqg->ttime.last_end_request = now; | |
4283 | #endif | |
4284 | ||
4285 | /* | |
4286 | * If this is the active queue, check if it needs to be expired, | |
4287 | * or if we want to idle in case it has no pending requests. | |
4288 | */ | |
4289 | if (cfqd->active_queue == cfqq) { | |
4290 | const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); | |
4291 | ||
4292 | if (cfq_cfqq_slice_new(cfqq)) { | |
4293 | cfq_set_prio_slice(cfqd, cfqq); | |
4294 | cfq_clear_cfqq_slice_new(cfqq); | |
4295 | } | |
4296 | ||
4297 | /* | |
4298 | * Should we wait for next request to come in before we expire | |
4299 | * the queue. | |
4300 | */ | |
4301 | if (cfq_should_wait_busy(cfqd, cfqq)) { | |
4302 | u64 extend_sl = cfqd->cfq_slice_idle; | |
4303 | if (!cfqd->cfq_slice_idle) | |
4304 | extend_sl = cfqd->cfq_group_idle; | |
4305 | cfqq->slice_end = now + extend_sl; | |
4306 | cfq_mark_cfqq_wait_busy(cfqq); | |
4307 | cfq_log_cfqq(cfqd, cfqq, "will busy wait"); | |
4308 | } | |
4309 | ||
4310 | /* | |
4311 | * Idling is not enabled on: | |
4312 | * - expired queues | |
4313 | * - idle-priority queues | |
4314 | * - async queues | |
4315 | * - queues with still some requests queued | |
4316 | * - when there is a close cooperator | |
4317 | */ | |
4318 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) | |
4319 | cfq_slice_expired(cfqd, 1); | |
4320 | else if (sync && cfqq_empty && | |
4321 | !cfq_close_cooperator(cfqd, cfqq)) { | |
4322 | cfq_arm_slice_timer(cfqd); | |
4323 | } | |
4324 | } | |
4325 | ||
4326 | if (!cfqd->rq_in_driver) | |
4327 | cfq_schedule_dispatch(cfqd); | |
4328 | } | |
4329 | ||
4330 | static void cfqq_boost_on_prio(struct cfq_queue *cfqq, unsigned int op) | |
4331 | { | |
4332 | /* | |
4333 | * If REQ_PRIO is set, boost class and prio level, if it's below | |
4334 | * BE/NORM. If prio is not set, restore the potentially boosted | |
4335 | * class/prio level. | |
4336 | */ | |
4337 | if (!(op & REQ_PRIO)) { | |
4338 | cfqq->ioprio_class = cfqq->org_ioprio_class; | |
4339 | cfqq->ioprio = cfqq->org_ioprio; | |
4340 | } else { | |
4341 | if (cfq_class_idle(cfqq)) | |
4342 | cfqq->ioprio_class = IOPRIO_CLASS_BE; | |
4343 | if (cfqq->ioprio > IOPRIO_NORM) | |
4344 | cfqq->ioprio = IOPRIO_NORM; | |
4345 | } | |
4346 | } | |
4347 | ||
4348 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) | |
4349 | { | |
4350 | if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { | |
4351 | cfq_mark_cfqq_must_alloc_slice(cfqq); | |
4352 | return ELV_MQUEUE_MUST; | |
4353 | } | |
4354 | ||
4355 | return ELV_MQUEUE_MAY; | |
4356 | } | |
4357 | ||
4358 | static int cfq_may_queue(struct request_queue *q, unsigned int op) | |
4359 | { | |
4360 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
4361 | struct task_struct *tsk = current; | |
4362 | struct cfq_io_cq *cic; | |
4363 | struct cfq_queue *cfqq; | |
4364 | ||
4365 | /* | |
4366 | * don't force setup of a queue from here, as a call to may_queue | |
4367 | * does not necessarily imply that a request actually will be queued. | |
4368 | * so just lookup a possibly existing queue, or return 'may queue' | |
4369 | * if that fails | |
4370 | */ | |
4371 | cic = cfq_cic_lookup(cfqd, tsk->io_context); | |
4372 | if (!cic) | |
4373 | return ELV_MQUEUE_MAY; | |
4374 | ||
4375 | cfqq = cic_to_cfqq(cic, op_is_sync(op)); | |
4376 | if (cfqq) { | |
4377 | cfq_init_prio_data(cfqq, cic); | |
4378 | cfqq_boost_on_prio(cfqq, op); | |
4379 | ||
4380 | return __cfq_may_queue(cfqq); | |
4381 | } | |
4382 | ||
4383 | return ELV_MQUEUE_MAY; | |
4384 | } | |
4385 | ||
4386 | /* | |
4387 | * queue lock held here | |
4388 | */ | |
4389 | static void cfq_put_request(struct request *rq) | |
4390 | { | |
4391 | struct cfq_queue *cfqq = RQ_CFQQ(rq); | |
4392 | ||
4393 | if (cfqq) { | |
4394 | const int rw = rq_data_dir(rq); | |
4395 | ||
4396 | BUG_ON(!cfqq->allocated[rw]); | |
4397 | cfqq->allocated[rw]--; | |
4398 | ||
4399 | /* Put down rq reference on cfqg */ | |
4400 | cfqg_put(RQ_CFQG(rq)); | |
4401 | rq->elv.priv[0] = NULL; | |
4402 | rq->elv.priv[1] = NULL; | |
4403 | ||
4404 | cfq_put_queue(cfqq); | |
4405 | } | |
4406 | } | |
4407 | ||
4408 | static struct cfq_queue * | |
4409 | cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_cq *cic, | |
4410 | struct cfq_queue *cfqq) | |
4411 | { | |
4412 | cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq); | |
4413 | cic_set_cfqq(cic, cfqq->new_cfqq, 1); | |
4414 | cfq_mark_cfqq_coop(cfqq->new_cfqq); | |
4415 | cfq_put_queue(cfqq); | |
4416 | return cic_to_cfqq(cic, 1); | |
4417 | } | |
4418 | ||
4419 | /* | |
4420 | * Returns NULL if a new cfqq should be allocated, or the old cfqq if this | |
4421 | * was the last process referring to said cfqq. | |
4422 | */ | |
4423 | static struct cfq_queue * | |
4424 | split_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq) | |
4425 | { | |
4426 | if (cfqq_process_refs(cfqq) == 1) { | |
4427 | cfqq->pid = current->pid; | |
4428 | cfq_clear_cfqq_coop(cfqq); | |
4429 | cfq_clear_cfqq_split_coop(cfqq); | |
4430 | return cfqq; | |
4431 | } | |
4432 | ||
4433 | cic_set_cfqq(cic, NULL, 1); | |
4434 | ||
4435 | cfq_put_cooperator(cfqq); | |
4436 | ||
4437 | cfq_put_queue(cfqq); | |
4438 | return NULL; | |
4439 | } | |
4440 | /* | |
4441 | * Allocate cfq data structures associated with this request. | |
4442 | */ | |
4443 | static int | |
4444 | cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio, | |
4445 | gfp_t gfp_mask) | |
4446 | { | |
4447 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
4448 | struct cfq_io_cq *cic = icq_to_cic(rq->elv.icq); | |
4449 | const int rw = rq_data_dir(rq); | |
4450 | const bool is_sync = rq_is_sync(rq); | |
4451 | struct cfq_queue *cfqq; | |
4452 | bool disable_wbt; | |
4453 | ||
4454 | spin_lock_irq(q->queue_lock); | |
4455 | ||
4456 | check_ioprio_changed(cic, bio); | |
4457 | disable_wbt = check_blkcg_changed(cic, bio); | |
4458 | new_queue: | |
4459 | cfqq = cic_to_cfqq(cic, is_sync); | |
4460 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { | |
4461 | if (cfqq) | |
4462 | cfq_put_queue(cfqq); | |
4463 | cfqq = cfq_get_queue(cfqd, is_sync, cic, bio); | |
4464 | cic_set_cfqq(cic, cfqq, is_sync); | |
4465 | } else { | |
4466 | /* | |
4467 | * If the queue was seeky for too long, break it apart. | |
4468 | */ | |
4469 | if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) { | |
4470 | cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq"); | |
4471 | cfqq = split_cfqq(cic, cfqq); | |
4472 | if (!cfqq) | |
4473 | goto new_queue; | |
4474 | } | |
4475 | ||
4476 | /* | |
4477 | * Check to see if this queue is scheduled to merge with | |
4478 | * another, closely cooperating queue. The merging of | |
4479 | * queues happens here as it must be done in process context. | |
4480 | * The reference on new_cfqq was taken in merge_cfqqs. | |
4481 | */ | |
4482 | if (cfqq->new_cfqq) | |
4483 | cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq); | |
4484 | } | |
4485 | ||
4486 | cfqq->allocated[rw]++; | |
4487 | ||
4488 | cfqq->ref++; | |
4489 | cfqg_get(cfqq->cfqg); | |
4490 | rq->elv.priv[0] = cfqq; | |
4491 | rq->elv.priv[1] = cfqq->cfqg; | |
4492 | spin_unlock_irq(q->queue_lock); | |
4493 | ||
4494 | if (disable_wbt) | |
4495 | wbt_disable_default(q); | |
4496 | ||
4497 | return 0; | |
4498 | } | |
4499 | ||
4500 | static void cfq_kick_queue(struct work_struct *work) | |
4501 | { | |
4502 | struct cfq_data *cfqd = | |
4503 | container_of(work, struct cfq_data, unplug_work); | |
4504 | struct request_queue *q = cfqd->queue; | |
4505 | ||
4506 | spin_lock_irq(q->queue_lock); | |
4507 | __blk_run_queue(cfqd->queue); | |
4508 | spin_unlock_irq(q->queue_lock); | |
4509 | } | |
4510 | ||
4511 | /* | |
4512 | * Timer running if the active_queue is currently idling inside its time slice | |
4513 | */ | |
4514 | static enum hrtimer_restart cfq_idle_slice_timer(struct hrtimer *timer) | |
4515 | { | |
4516 | struct cfq_data *cfqd = container_of(timer, struct cfq_data, | |
4517 | idle_slice_timer); | |
4518 | struct cfq_queue *cfqq; | |
4519 | unsigned long flags; | |
4520 | int timed_out = 1; | |
4521 | ||
4522 | cfq_log(cfqd, "idle timer fired"); | |
4523 | ||
4524 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); | |
4525 | ||
4526 | cfqq = cfqd->active_queue; | |
4527 | if (cfqq) { | |
4528 | timed_out = 0; | |
4529 | ||
4530 | /* | |
4531 | * We saw a request before the queue expired, let it through | |
4532 | */ | |
4533 | if (cfq_cfqq_must_dispatch(cfqq)) | |
4534 | goto out_kick; | |
4535 | ||
4536 | /* | |
4537 | * expired | |
4538 | */ | |
4539 | if (cfq_slice_used(cfqq)) | |
4540 | goto expire; | |
4541 | ||
4542 | /* | |
4543 | * only expire and reinvoke request handler, if there are | |
4544 | * other queues with pending requests | |
4545 | */ | |
4546 | if (!cfqd->busy_queues) | |
4547 | goto out_cont; | |
4548 | ||
4549 | /* | |
4550 | * not expired and it has a request pending, let it dispatch | |
4551 | */ | |
4552 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) | |
4553 | goto out_kick; | |
4554 | ||
4555 | /* | |
4556 | * Queue depth flag is reset only when the idle didn't succeed | |
4557 | */ | |
4558 | cfq_clear_cfqq_deep(cfqq); | |
4559 | } | |
4560 | expire: | |
4561 | cfq_slice_expired(cfqd, timed_out); | |
4562 | out_kick: | |
4563 | cfq_schedule_dispatch(cfqd); | |
4564 | out_cont: | |
4565 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); | |
4566 | return HRTIMER_NORESTART; | |
4567 | } | |
4568 | ||
4569 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) | |
4570 | { | |
4571 | hrtimer_cancel(&cfqd->idle_slice_timer); | |
4572 | cancel_work_sync(&cfqd->unplug_work); | |
4573 | } | |
4574 | ||
4575 | static void cfq_exit_queue(struct elevator_queue *e) | |
4576 | { | |
4577 | struct cfq_data *cfqd = e->elevator_data; | |
4578 | struct request_queue *q = cfqd->queue; | |
4579 | ||
4580 | cfq_shutdown_timer_wq(cfqd); | |
4581 | ||
4582 | spin_lock_irq(q->queue_lock); | |
4583 | ||
4584 | if (cfqd->active_queue) | |
4585 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0); | |
4586 | ||
4587 | spin_unlock_irq(q->queue_lock); | |
4588 | ||
4589 | cfq_shutdown_timer_wq(cfqd); | |
4590 | ||
4591 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
4592 | blkcg_deactivate_policy(q, &blkcg_policy_cfq); | |
4593 | #else | |
4594 | kfree(cfqd->root_group); | |
4595 | #endif | |
4596 | kfree(cfqd); | |
4597 | } | |
4598 | ||
4599 | static int cfq_init_queue(struct request_queue *q, struct elevator_type *e) | |
4600 | { | |
4601 | struct cfq_data *cfqd; | |
4602 | struct blkcg_gq *blkg __maybe_unused; | |
4603 | int i, ret; | |
4604 | struct elevator_queue *eq; | |
4605 | ||
4606 | eq = elevator_alloc(q, e); | |
4607 | if (!eq) | |
4608 | return -ENOMEM; | |
4609 | ||
4610 | cfqd = kzalloc_node(sizeof(*cfqd), GFP_KERNEL, q->node); | |
4611 | if (!cfqd) { | |
4612 | kobject_put(&eq->kobj); | |
4613 | return -ENOMEM; | |
4614 | } | |
4615 | eq->elevator_data = cfqd; | |
4616 | ||
4617 | cfqd->queue = q; | |
4618 | spin_lock_irq(q->queue_lock); | |
4619 | q->elevator = eq; | |
4620 | spin_unlock_irq(q->queue_lock); | |
4621 | ||
4622 | /* Init root service tree */ | |
4623 | cfqd->grp_service_tree = CFQ_RB_ROOT; | |
4624 | ||
4625 | /* Init root group and prefer root group over other groups by default */ | |
4626 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
4627 | ret = blkcg_activate_policy(q, &blkcg_policy_cfq); | |
4628 | if (ret) | |
4629 | goto out_free; | |
4630 | ||
4631 | cfqd->root_group = blkg_to_cfqg(q->root_blkg); | |
4632 | #else | |
4633 | ret = -ENOMEM; | |
4634 | cfqd->root_group = kzalloc_node(sizeof(*cfqd->root_group), | |
4635 | GFP_KERNEL, cfqd->queue->node); | |
4636 | if (!cfqd->root_group) | |
4637 | goto out_free; | |
4638 | ||
4639 | cfq_init_cfqg_base(cfqd->root_group); | |
4640 | cfqd->root_group->weight = 2 * CFQ_WEIGHT_LEGACY_DFL; | |
4641 | cfqd->root_group->leaf_weight = 2 * CFQ_WEIGHT_LEGACY_DFL; | |
4642 | #endif | |
4643 | ||
4644 | /* | |
4645 | * Not strictly needed (since RB_ROOT just clears the node and we | |
4646 | * zeroed cfqd on alloc), but better be safe in case someone decides | |
4647 | * to add magic to the rb code | |
4648 | */ | |
4649 | for (i = 0; i < CFQ_PRIO_LISTS; i++) | |
4650 | cfqd->prio_trees[i] = RB_ROOT; | |
4651 | ||
4652 | /* | |
4653 | * Our fallback cfqq if cfq_get_queue() runs into OOM issues. | |
4654 | * Grab a permanent reference to it, so that the normal code flow | |
4655 | * will not attempt to free it. oom_cfqq is linked to root_group | |
4656 | * but shouldn't hold a reference as it'll never be unlinked. Lose | |
4657 | * the reference from linking right away. | |
4658 | */ | |
4659 | cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); | |
4660 | cfqd->oom_cfqq.ref++; | |
4661 | ||
4662 | spin_lock_irq(q->queue_lock); | |
4663 | cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, cfqd->root_group); | |
4664 | cfqg_put(cfqd->root_group); | |
4665 | spin_unlock_irq(q->queue_lock); | |
4666 | ||
4667 | hrtimer_init(&cfqd->idle_slice_timer, CLOCK_MONOTONIC, | |
4668 | HRTIMER_MODE_REL); | |
4669 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; | |
4670 | ||
4671 | INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); | |
4672 | ||
4673 | cfqd->cfq_quantum = cfq_quantum; | |
4674 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; | |
4675 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; | |
4676 | cfqd->cfq_back_max = cfq_back_max; | |
4677 | cfqd->cfq_back_penalty = cfq_back_penalty; | |
4678 | cfqd->cfq_slice[0] = cfq_slice_async; | |
4679 | cfqd->cfq_slice[1] = cfq_slice_sync; | |
4680 | cfqd->cfq_target_latency = cfq_target_latency; | |
4681 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; | |
4682 | cfqd->cfq_slice_idle = cfq_slice_idle; | |
4683 | cfqd->cfq_group_idle = cfq_group_idle; | |
4684 | cfqd->cfq_latency = 1; | |
4685 | cfqd->hw_tag = -1; | |
4686 | /* | |
4687 | * we optimistically start assuming sync ops weren't delayed in last | |
4688 | * second, in order to have larger depth for async operations. | |
4689 | */ | |
4690 | cfqd->last_delayed_sync = ktime_get_ns() - NSEC_PER_SEC; | |
4691 | return 0; | |
4692 | ||
4693 | out_free: | |
4694 | kfree(cfqd); | |
4695 | kobject_put(&eq->kobj); | |
4696 | return ret; | |
4697 | } | |
4698 | ||
4699 | static void cfq_registered_queue(struct request_queue *q) | |
4700 | { | |
4701 | struct elevator_queue *e = q->elevator; | |
4702 | struct cfq_data *cfqd = e->elevator_data; | |
4703 | ||
4704 | /* | |
4705 | * Default to IOPS mode with no idling for SSDs | |
4706 | */ | |
4707 | if (blk_queue_nonrot(q)) | |
4708 | cfqd->cfq_slice_idle = 0; | |
4709 | } | |
4710 | ||
4711 | /* | |
4712 | * sysfs parts below --> | |
4713 | */ | |
4714 | static ssize_t | |
4715 | cfq_var_show(unsigned int var, char *page) | |
4716 | { | |
4717 | return sprintf(page, "%u\n", var); | |
4718 | } | |
4719 | ||
4720 | static ssize_t | |
4721 | cfq_var_store(unsigned int *var, const char *page, size_t count) | |
4722 | { | |
4723 | char *p = (char *) page; | |
4724 | ||
4725 | *var = simple_strtoul(p, &p, 10); | |
4726 | return count; | |
4727 | } | |
4728 | ||
4729 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ | |
4730 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ | |
4731 | { \ | |
4732 | struct cfq_data *cfqd = e->elevator_data; \ | |
4733 | u64 __data = __VAR; \ | |
4734 | if (__CONV) \ | |
4735 | __data = div_u64(__data, NSEC_PER_MSEC); \ | |
4736 | return cfq_var_show(__data, (page)); \ | |
4737 | } | |
4738 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); | |
4739 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); | |
4740 | SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1); | |
4741 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); | |
4742 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); | |
4743 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); | |
4744 | SHOW_FUNCTION(cfq_group_idle_show, cfqd->cfq_group_idle, 1); | |
4745 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); | |
4746 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); | |
4747 | SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); | |
4748 | SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); | |
4749 | SHOW_FUNCTION(cfq_target_latency_show, cfqd->cfq_target_latency, 1); | |
4750 | #undef SHOW_FUNCTION | |
4751 | ||
4752 | #define USEC_SHOW_FUNCTION(__FUNC, __VAR) \ | |
4753 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ | |
4754 | { \ | |
4755 | struct cfq_data *cfqd = e->elevator_data; \ | |
4756 | u64 __data = __VAR; \ | |
4757 | __data = div_u64(__data, NSEC_PER_USEC); \ | |
4758 | return cfq_var_show(__data, (page)); \ | |
4759 | } | |
4760 | USEC_SHOW_FUNCTION(cfq_slice_idle_us_show, cfqd->cfq_slice_idle); | |
4761 | USEC_SHOW_FUNCTION(cfq_group_idle_us_show, cfqd->cfq_group_idle); | |
4762 | USEC_SHOW_FUNCTION(cfq_slice_sync_us_show, cfqd->cfq_slice[1]); | |
4763 | USEC_SHOW_FUNCTION(cfq_slice_async_us_show, cfqd->cfq_slice[0]); | |
4764 | USEC_SHOW_FUNCTION(cfq_target_latency_us_show, cfqd->cfq_target_latency); | |
4765 | #undef USEC_SHOW_FUNCTION | |
4766 | ||
4767 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ | |
4768 | static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ | |
4769 | { \ | |
4770 | struct cfq_data *cfqd = e->elevator_data; \ | |
4771 | unsigned int __data; \ | |
4772 | int ret = cfq_var_store(&__data, (page), count); \ | |
4773 | if (__data < (MIN)) \ | |
4774 | __data = (MIN); \ | |
4775 | else if (__data > (MAX)) \ | |
4776 | __data = (MAX); \ | |
4777 | if (__CONV) \ | |
4778 | *(__PTR) = (u64)__data * NSEC_PER_MSEC; \ | |
4779 | else \ | |
4780 | *(__PTR) = __data; \ | |
4781 | return ret; \ | |
4782 | } | |
4783 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); | |
4784 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, | |
4785 | UINT_MAX, 1); | |
4786 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, | |
4787 | UINT_MAX, 1); | |
4788 | STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0); | |
4789 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, | |
4790 | UINT_MAX, 0); | |
4791 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); | |
4792 | STORE_FUNCTION(cfq_group_idle_store, &cfqd->cfq_group_idle, 0, UINT_MAX, 1); | |
4793 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); | |
4794 | STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1); | |
4795 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, | |
4796 | UINT_MAX, 0); | |
4797 | STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); | |
4798 | STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1, UINT_MAX, 1); | |
4799 | #undef STORE_FUNCTION | |
4800 | ||
4801 | #define USEC_STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \ | |
4802 | static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ | |
4803 | { \ | |
4804 | struct cfq_data *cfqd = e->elevator_data; \ | |
4805 | unsigned int __data; \ | |
4806 | int ret = cfq_var_store(&__data, (page), count); \ | |
4807 | if (__data < (MIN)) \ | |
4808 | __data = (MIN); \ | |
4809 | else if (__data > (MAX)) \ | |
4810 | __data = (MAX); \ | |
4811 | *(__PTR) = (u64)__data * NSEC_PER_USEC; \ | |
4812 | return ret; \ | |
4813 | } | |
4814 | USEC_STORE_FUNCTION(cfq_slice_idle_us_store, &cfqd->cfq_slice_idle, 0, UINT_MAX); | |
4815 | USEC_STORE_FUNCTION(cfq_group_idle_us_store, &cfqd->cfq_group_idle, 0, UINT_MAX); | |
4816 | USEC_STORE_FUNCTION(cfq_slice_sync_us_store, &cfqd->cfq_slice[1], 1, UINT_MAX); | |
4817 | USEC_STORE_FUNCTION(cfq_slice_async_us_store, &cfqd->cfq_slice[0], 1, UINT_MAX); | |
4818 | USEC_STORE_FUNCTION(cfq_target_latency_us_store, &cfqd->cfq_target_latency, 1, UINT_MAX); | |
4819 | #undef USEC_STORE_FUNCTION | |
4820 | ||
4821 | #define CFQ_ATTR(name) \ | |
4822 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) | |
4823 | ||
4824 | static struct elv_fs_entry cfq_attrs[] = { | |
4825 | CFQ_ATTR(quantum), | |
4826 | CFQ_ATTR(fifo_expire_sync), | |
4827 | CFQ_ATTR(fifo_expire_async), | |
4828 | CFQ_ATTR(back_seek_max), | |
4829 | CFQ_ATTR(back_seek_penalty), | |
4830 | CFQ_ATTR(slice_sync), | |
4831 | CFQ_ATTR(slice_sync_us), | |
4832 | CFQ_ATTR(slice_async), | |
4833 | CFQ_ATTR(slice_async_us), | |
4834 | CFQ_ATTR(slice_async_rq), | |
4835 | CFQ_ATTR(slice_idle), | |
4836 | CFQ_ATTR(slice_idle_us), | |
4837 | CFQ_ATTR(group_idle), | |
4838 | CFQ_ATTR(group_idle_us), | |
4839 | CFQ_ATTR(low_latency), | |
4840 | CFQ_ATTR(target_latency), | |
4841 | CFQ_ATTR(target_latency_us), | |
4842 | __ATTR_NULL | |
4843 | }; | |
4844 | ||
4845 | static struct elevator_type iosched_cfq = { | |
4846 | .ops.sq = { | |
4847 | .elevator_merge_fn = cfq_merge, | |
4848 | .elevator_merged_fn = cfq_merged_request, | |
4849 | .elevator_merge_req_fn = cfq_merged_requests, | |
4850 | .elevator_allow_bio_merge_fn = cfq_allow_bio_merge, | |
4851 | .elevator_allow_rq_merge_fn = cfq_allow_rq_merge, | |
4852 | .elevator_bio_merged_fn = cfq_bio_merged, | |
4853 | .elevator_dispatch_fn = cfq_dispatch_requests, | |
4854 | .elevator_add_req_fn = cfq_insert_request, | |
4855 | .elevator_activate_req_fn = cfq_activate_request, | |
4856 | .elevator_deactivate_req_fn = cfq_deactivate_request, | |
4857 | .elevator_completed_req_fn = cfq_completed_request, | |
4858 | .elevator_former_req_fn = elv_rb_former_request, | |
4859 | .elevator_latter_req_fn = elv_rb_latter_request, | |
4860 | .elevator_init_icq_fn = cfq_init_icq, | |
4861 | .elevator_exit_icq_fn = cfq_exit_icq, | |
4862 | .elevator_set_req_fn = cfq_set_request, | |
4863 | .elevator_put_req_fn = cfq_put_request, | |
4864 | .elevator_may_queue_fn = cfq_may_queue, | |
4865 | .elevator_init_fn = cfq_init_queue, | |
4866 | .elevator_exit_fn = cfq_exit_queue, | |
4867 | .elevator_registered_fn = cfq_registered_queue, | |
4868 | }, | |
4869 | .icq_size = sizeof(struct cfq_io_cq), | |
4870 | .icq_align = __alignof__(struct cfq_io_cq), | |
4871 | .elevator_attrs = cfq_attrs, | |
4872 | .elevator_name = "cfq", | |
4873 | .elevator_owner = THIS_MODULE, | |
4874 | }; | |
4875 | ||
4876 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
4877 | static struct blkcg_policy blkcg_policy_cfq = { | |
4878 | .dfl_cftypes = cfq_blkcg_files, | |
4879 | .legacy_cftypes = cfq_blkcg_legacy_files, | |
4880 | ||
4881 | .cpd_alloc_fn = cfq_cpd_alloc, | |
4882 | .cpd_init_fn = cfq_cpd_init, | |
4883 | .cpd_free_fn = cfq_cpd_free, | |
4884 | .cpd_bind_fn = cfq_cpd_bind, | |
4885 | ||
4886 | .pd_alloc_fn = cfq_pd_alloc, | |
4887 | .pd_init_fn = cfq_pd_init, | |
4888 | .pd_offline_fn = cfq_pd_offline, | |
4889 | .pd_free_fn = cfq_pd_free, | |
4890 | .pd_reset_stats_fn = cfq_pd_reset_stats, | |
4891 | }; | |
4892 | #endif | |
4893 | ||
4894 | static int __init cfq_init(void) | |
4895 | { | |
4896 | int ret; | |
4897 | ||
4898 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
4899 | ret = blkcg_policy_register(&blkcg_policy_cfq); | |
4900 | if (ret) | |
4901 | return ret; | |
4902 | #else | |
4903 | cfq_group_idle = 0; | |
4904 | #endif | |
4905 | ||
4906 | ret = -ENOMEM; | |
4907 | cfq_pool = KMEM_CACHE(cfq_queue, 0); | |
4908 | if (!cfq_pool) | |
4909 | goto err_pol_unreg; | |
4910 | ||
4911 | ret = elv_register(&iosched_cfq); | |
4912 | if (ret) | |
4913 | goto err_free_pool; | |
4914 | ||
4915 | return 0; | |
4916 | ||
4917 | err_free_pool: | |
4918 | kmem_cache_destroy(cfq_pool); | |
4919 | err_pol_unreg: | |
4920 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
4921 | blkcg_policy_unregister(&blkcg_policy_cfq); | |
4922 | #endif | |
4923 | return ret; | |
4924 | } | |
4925 | ||
4926 | static void __exit cfq_exit(void) | |
4927 | { | |
4928 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
4929 | blkcg_policy_unregister(&blkcg_policy_cfq); | |
4930 | #endif | |
4931 | elv_unregister(&iosched_cfq); | |
4932 | kmem_cache_destroy(cfq_pool); | |
4933 | } | |
4934 | ||
4935 | module_init(cfq_init); | |
4936 | module_exit(cfq_exit); | |
4937 | ||
4938 | MODULE_AUTHOR("Jens Axboe"); | |
4939 | MODULE_LICENSE("GPL"); | |
4940 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |