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