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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * cgroups support for the BFQ I/O scheduler.
4 */
5#include <linux/module.h>
6#include <linux/slab.h>
7#include <linux/blkdev.h>
8#include <linux/cgroup.h>
9#include <linux/ktime.h>
10#include <linux/rbtree.h>
11#include <linux/ioprio.h>
12#include <linux/sbitmap.h>
13#include <linux/delay.h>
14
15#include "elevator.h"
16#include "bfq-iosched.h"
17
18#ifdef CONFIG_BFQ_CGROUP_DEBUG
19static int bfq_stat_init(struct bfq_stat *stat, gfp_t gfp)
20{
21 int ret;
22
23 ret = percpu_counter_init(&stat->cpu_cnt, 0, gfp);
24 if (ret)
25 return ret;
26
27 atomic64_set(v: &stat->aux_cnt, i: 0);
28 return 0;
29}
30
31static void bfq_stat_exit(struct bfq_stat *stat)
32{
33 percpu_counter_destroy(fbc: &stat->cpu_cnt);
34}
35
36/**
37 * bfq_stat_add - add a value to a bfq_stat
38 * @stat: target bfq_stat
39 * @val: value to add
40 *
41 * Add @val to @stat. The caller must ensure that IRQ on the same CPU
42 * don't re-enter this function for the same counter.
43 */
44static inline void bfq_stat_add(struct bfq_stat *stat, uint64_t val)
45{
46 percpu_counter_add_batch(fbc: &stat->cpu_cnt, amount: val, BLKG_STAT_CPU_BATCH);
47}
48
49/**
50 * bfq_stat_read - read the current value of a bfq_stat
51 * @stat: bfq_stat to read
52 */
53static inline uint64_t bfq_stat_read(struct bfq_stat *stat)
54{
55 return percpu_counter_sum_positive(fbc: &stat->cpu_cnt);
56}
57
58/**
59 * bfq_stat_reset - reset a bfq_stat
60 * @stat: bfq_stat to reset
61 */
62static inline void bfq_stat_reset(struct bfq_stat *stat)
63{
64 percpu_counter_set(fbc: &stat->cpu_cnt, amount: 0);
65 atomic64_set(v: &stat->aux_cnt, i: 0);
66}
67
68/**
69 * bfq_stat_add_aux - add a bfq_stat into another's aux count
70 * @to: the destination bfq_stat
71 * @from: the source
72 *
73 * Add @from's count including the aux one to @to's aux count.
74 */
75static inline void bfq_stat_add_aux(struct bfq_stat *to,
76 struct bfq_stat *from)
77{
78 atomic64_add(i: bfq_stat_read(stat: from) + atomic64_read(v: &from->aux_cnt),
79 v: &to->aux_cnt);
80}
81
82/**
83 * blkg_prfill_stat - prfill callback for bfq_stat
84 * @sf: seq_file to print to
85 * @pd: policy private data of interest
86 * @off: offset to the bfq_stat in @pd
87 *
88 * prfill callback for printing a bfq_stat.
89 */
90static u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd,
91 int off)
92{
93 return __blkg_prfill_u64(sf, pd, v: bfq_stat_read(stat: (void *)pd + off));
94}
95
96/* bfqg stats flags */
97enum bfqg_stats_flags {
98 BFQG_stats_waiting = 0,
99 BFQG_stats_idling,
100 BFQG_stats_empty,
101};
102
103#define BFQG_FLAG_FNS(name) \
104static void bfqg_stats_mark_##name(struct bfqg_stats *stats) \
105{ \
106 stats->flags |= (1 << BFQG_stats_##name); \
107} \
108static void bfqg_stats_clear_##name(struct bfqg_stats *stats) \
109{ \
110 stats->flags &= ~(1 << BFQG_stats_##name); \
111} \
112static int bfqg_stats_##name(struct bfqg_stats *stats) \
113{ \
114 return (stats->flags & (1 << BFQG_stats_##name)) != 0; \
115} \
116
117BFQG_FLAG_FNS(waiting)
118BFQG_FLAG_FNS(idling)
119BFQG_FLAG_FNS(empty)
120#undef BFQG_FLAG_FNS
121
122/* This should be called with the scheduler lock held. */
123static void bfqg_stats_update_group_wait_time(struct bfqg_stats *stats)
124{
125 u64 now;
126
127 if (!bfqg_stats_waiting(stats))
128 return;
129
130 now = blk_time_get_ns();
131 if (now > stats->start_group_wait_time)
132 bfq_stat_add(stat: &stats->group_wait_time,
133 val: now - stats->start_group_wait_time);
134 bfqg_stats_clear_waiting(stats);
135}
136
137/* This should be called with the scheduler lock held. */
138static void bfqg_stats_set_start_group_wait_time(struct bfq_group *bfqg,
139 struct bfq_group *curr_bfqg)
140{
141 struct bfqg_stats *stats = &bfqg->stats;
142
143 if (bfqg_stats_waiting(stats))
144 return;
145 if (bfqg == curr_bfqg)
146 return;
147 stats->start_group_wait_time = blk_time_get_ns();
148 bfqg_stats_mark_waiting(stats);
149}
150
151/* This should be called with the scheduler lock held. */
152static void bfqg_stats_end_empty_time(struct bfqg_stats *stats)
153{
154 u64 now;
155
156 if (!bfqg_stats_empty(stats))
157 return;
158
159 now = blk_time_get_ns();
160 if (now > stats->start_empty_time)
161 bfq_stat_add(stat: &stats->empty_time,
162 val: now - stats->start_empty_time);
163 bfqg_stats_clear_empty(stats);
164}
165
166void bfqg_stats_update_dequeue(struct bfq_group *bfqg)
167{
168 bfq_stat_add(stat: &bfqg->stats.dequeue, val: 1);
169}
170
171void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg)
172{
173 struct bfqg_stats *stats = &bfqg->stats;
174
175 if (blkg_rwstat_total(rwstat: &stats->queued))
176 return;
177
178 /*
179 * group is already marked empty. This can happen if bfqq got new
180 * request in parent group and moved to this group while being added
181 * to service tree. Just ignore the event and move on.
182 */
183 if (bfqg_stats_empty(stats))
184 return;
185
186 stats->start_empty_time = blk_time_get_ns();
187 bfqg_stats_mark_empty(stats);
188}
189
190void bfqg_stats_update_idle_time(struct bfq_group *bfqg)
191{
192 struct bfqg_stats *stats = &bfqg->stats;
193
194 if (bfqg_stats_idling(stats)) {
195 u64 now = blk_time_get_ns();
196
197 if (now > stats->start_idle_time)
198 bfq_stat_add(stat: &stats->idle_time,
199 val: now - stats->start_idle_time);
200 bfqg_stats_clear_idling(stats);
201 }
202}
203
204void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg)
205{
206 struct bfqg_stats *stats = &bfqg->stats;
207
208 stats->start_idle_time = blk_time_get_ns();
209 bfqg_stats_mark_idling(stats);
210}
211
212void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg)
213{
214 struct bfqg_stats *stats = &bfqg->stats;
215
216 bfq_stat_add(stat: &stats->avg_queue_size_sum,
217 val: blkg_rwstat_total(rwstat: &stats->queued));
218 bfq_stat_add(stat: &stats->avg_queue_size_samples, val: 1);
219 bfqg_stats_update_group_wait_time(stats);
220}
221
222void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq,
223 blk_opf_t opf)
224{
225 blkg_rwstat_add(rwstat: &bfqg->stats.queued, opf, val: 1);
226 bfqg_stats_end_empty_time(stats: &bfqg->stats);
227 if (!(bfqq == bfqg->bfqd->in_service_queue))
228 bfqg_stats_set_start_group_wait_time(bfqg, curr_bfqg: bfqq_group(bfqq));
229}
230
231void bfqg_stats_update_io_remove(struct bfq_group *bfqg, blk_opf_t opf)
232{
233 blkg_rwstat_add(rwstat: &bfqg->stats.queued, opf, val: -1);
234}
235
236void bfqg_stats_update_io_merged(struct bfq_group *bfqg, blk_opf_t opf)
237{
238 blkg_rwstat_add(rwstat: &bfqg->stats.merged, opf, val: 1);
239}
240
241void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns,
242 u64 io_start_time_ns, blk_opf_t opf)
243{
244 struct bfqg_stats *stats = &bfqg->stats;
245 u64 now = blk_time_get_ns();
246
247 if (now > io_start_time_ns)
248 blkg_rwstat_add(rwstat: &stats->service_time, opf,
249 val: now - io_start_time_ns);
250 if (io_start_time_ns > start_time_ns)
251 blkg_rwstat_add(rwstat: &stats->wait_time, opf,
252 val: io_start_time_ns - start_time_ns);
253}
254
255#else /* CONFIG_BFQ_CGROUP_DEBUG */
256
257void bfqg_stats_update_io_remove(struct bfq_group *bfqg, blk_opf_t opf) { }
258void bfqg_stats_update_io_merged(struct bfq_group *bfqg, blk_opf_t opf) { }
259void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns,
260 u64 io_start_time_ns, blk_opf_t opf) { }
261void bfqg_stats_update_dequeue(struct bfq_group *bfqg) { }
262void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg) { }
263
264#endif /* CONFIG_BFQ_CGROUP_DEBUG */
265
266#ifdef CONFIG_BFQ_GROUP_IOSCHED
267
268/*
269 * blk-cgroup policy-related handlers
270 * The following functions help in converting between blk-cgroup
271 * internal structures and BFQ-specific structures.
272 */
273
274static struct bfq_group *pd_to_bfqg(struct blkg_policy_data *pd)
275{
276 return pd ? container_of(pd, struct bfq_group, pd) : NULL;
277}
278
279struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg)
280{
281 return pd_to_blkg(pd: &bfqg->pd);
282}
283
284static struct bfq_group *blkg_to_bfqg(struct blkcg_gq *blkg)
285{
286 return pd_to_bfqg(pd: blkg_to_pd(blkg, pol: &blkcg_policy_bfq));
287}
288
289/*
290 * bfq_group handlers
291 * The following functions help in navigating the bfq_group hierarchy
292 * by allowing to find the parent of a bfq_group or the bfq_group
293 * associated to a bfq_queue.
294 */
295
296static struct bfq_group *bfqg_parent(struct bfq_group *bfqg)
297{
298 struct blkcg_gq *pblkg = bfqg_to_blkg(bfqg)->parent;
299
300 return pblkg ? blkg_to_bfqg(blkg: pblkg) : NULL;
301}
302
303struct bfq_group *bfqq_group(struct bfq_queue *bfqq)
304{
305 struct bfq_entity *group_entity = bfqq->entity.parent;
306
307 return group_entity ? container_of(group_entity, struct bfq_group,
308 entity) :
309 bfqq->bfqd->root_group;
310}
311
312/*
313 * The following two functions handle get and put of a bfq_group by
314 * wrapping the related blk-cgroup hooks.
315 */
316
317static void bfqg_get(struct bfq_group *bfqg)
318{
319 refcount_inc(r: &bfqg->ref);
320}
321
322static void bfqg_put(struct bfq_group *bfqg)
323{
324 if (refcount_dec_and_test(r: &bfqg->ref))
325 kfree(objp: bfqg);
326}
327
328static void bfqg_and_blkg_get(struct bfq_group *bfqg)
329{
330 /* see comments in bfq_bic_update_cgroup for why refcounting bfqg */
331 bfqg_get(bfqg);
332
333 blkg_get(blkg: bfqg_to_blkg(bfqg));
334}
335
336void bfqg_and_blkg_put(struct bfq_group *bfqg)
337{
338 blkg_put(blkg: bfqg_to_blkg(bfqg));
339
340 bfqg_put(bfqg);
341}
342
343void bfqg_stats_update_legacy_io(struct request_queue *q, struct request *rq)
344{
345 struct bfq_group *bfqg = blkg_to_bfqg(blkg: rq->bio->bi_blkg);
346
347 if (!bfqg)
348 return;
349
350 blkg_rwstat_add(rwstat: &bfqg->stats.bytes, opf: rq->cmd_flags, val: blk_rq_bytes(rq));
351 blkg_rwstat_add(rwstat: &bfqg->stats.ios, opf: rq->cmd_flags, val: 1);
352}
353
354/* @stats = 0 */
355static void bfqg_stats_reset(struct bfqg_stats *stats)
356{
357#ifdef CONFIG_BFQ_CGROUP_DEBUG
358 /* queued stats shouldn't be cleared */
359 blkg_rwstat_reset(rwstat: &stats->merged);
360 blkg_rwstat_reset(rwstat: &stats->service_time);
361 blkg_rwstat_reset(rwstat: &stats->wait_time);
362 bfq_stat_reset(stat: &stats->time);
363 bfq_stat_reset(stat: &stats->avg_queue_size_sum);
364 bfq_stat_reset(stat: &stats->avg_queue_size_samples);
365 bfq_stat_reset(stat: &stats->dequeue);
366 bfq_stat_reset(stat: &stats->group_wait_time);
367 bfq_stat_reset(stat: &stats->idle_time);
368 bfq_stat_reset(stat: &stats->empty_time);
369#endif
370}
371
372/* @to += @from */
373static void bfqg_stats_add_aux(struct bfqg_stats *to, struct bfqg_stats *from)
374{
375 if (!to || !from)
376 return;
377
378#ifdef CONFIG_BFQ_CGROUP_DEBUG
379 /* queued stats shouldn't be cleared */
380 blkg_rwstat_add_aux(to: &to->merged, from: &from->merged);
381 blkg_rwstat_add_aux(to: &to->service_time, from: &from->service_time);
382 blkg_rwstat_add_aux(to: &to->wait_time, from: &from->wait_time);
383 bfq_stat_add_aux(to: &to->time, from: &from->time);
384 bfq_stat_add_aux(to: &to->avg_queue_size_sum, from: &from->avg_queue_size_sum);
385 bfq_stat_add_aux(to: &to->avg_queue_size_samples,
386 from: &from->avg_queue_size_samples);
387 bfq_stat_add_aux(to: &to->dequeue, from: &from->dequeue);
388 bfq_stat_add_aux(to: &to->group_wait_time, from: &from->group_wait_time);
389 bfq_stat_add_aux(to: &to->idle_time, from: &from->idle_time);
390 bfq_stat_add_aux(to: &to->empty_time, from: &from->empty_time);
391#endif
392}
393
394/*
395 * Transfer @bfqg's stats to its parent's aux counts so that the ancestors'
396 * recursive stats can still account for the amount used by this bfqg after
397 * it's gone.
398 */
399static void bfqg_stats_xfer_dead(struct bfq_group *bfqg)
400{
401 struct bfq_group *parent;
402
403 if (!bfqg) /* root_group */
404 return;
405
406 parent = bfqg_parent(bfqg);
407
408 lockdep_assert_held(&bfqg_to_blkg(bfqg)->q->queue_lock);
409
410 if (unlikely(!parent))
411 return;
412
413 bfqg_stats_add_aux(to: &parent->stats, from: &bfqg->stats);
414 bfqg_stats_reset(stats: &bfqg->stats);
415}
416
417void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg)
418{
419 struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
420
421 entity->weight = entity->new_weight;
422 entity->orig_weight = entity->new_weight;
423 if (bfqq) {
424 bfqq->ioprio = bfqq->new_ioprio;
425 bfqq->ioprio_class = bfqq->new_ioprio_class;
426 /*
427 * Make sure that bfqg and its associated blkg do not
428 * disappear before entity.
429 */
430 bfqg_and_blkg_get(bfqg);
431 }
432 entity->parent = bfqg->my_entity; /* NULL for root group */
433 entity->sched_data = &bfqg->sched_data;
434}
435
436static void bfqg_stats_exit(struct bfqg_stats *stats)
437{
438 blkg_rwstat_exit(rwstat: &stats->bytes);
439 blkg_rwstat_exit(rwstat: &stats->ios);
440#ifdef CONFIG_BFQ_CGROUP_DEBUG
441 blkg_rwstat_exit(rwstat: &stats->merged);
442 blkg_rwstat_exit(rwstat: &stats->service_time);
443 blkg_rwstat_exit(rwstat: &stats->wait_time);
444 blkg_rwstat_exit(rwstat: &stats->queued);
445 bfq_stat_exit(stat: &stats->time);
446 bfq_stat_exit(stat: &stats->avg_queue_size_sum);
447 bfq_stat_exit(stat: &stats->avg_queue_size_samples);
448 bfq_stat_exit(stat: &stats->dequeue);
449 bfq_stat_exit(stat: &stats->group_wait_time);
450 bfq_stat_exit(stat: &stats->idle_time);
451 bfq_stat_exit(stat: &stats->empty_time);
452#endif
453}
454
455static int bfqg_stats_init(struct bfqg_stats *stats, gfp_t gfp)
456{
457 if (blkg_rwstat_init(rwstat: &stats->bytes, gfp) ||
458 blkg_rwstat_init(rwstat: &stats->ios, gfp))
459 goto error;
460
461#ifdef CONFIG_BFQ_CGROUP_DEBUG
462 if (blkg_rwstat_init(rwstat: &stats->merged, gfp) ||
463 blkg_rwstat_init(rwstat: &stats->service_time, gfp) ||
464 blkg_rwstat_init(rwstat: &stats->wait_time, gfp) ||
465 blkg_rwstat_init(rwstat: &stats->queued, gfp) ||
466 bfq_stat_init(stat: &stats->time, gfp) ||
467 bfq_stat_init(stat: &stats->avg_queue_size_sum, gfp) ||
468 bfq_stat_init(stat: &stats->avg_queue_size_samples, gfp) ||
469 bfq_stat_init(stat: &stats->dequeue, gfp) ||
470 bfq_stat_init(stat: &stats->group_wait_time, gfp) ||
471 bfq_stat_init(stat: &stats->idle_time, gfp) ||
472 bfq_stat_init(stat: &stats->empty_time, gfp))
473 goto error;
474#endif
475
476 return 0;
477
478error:
479 bfqg_stats_exit(stats);
480 return -ENOMEM;
481}
482
483static struct bfq_group_data *cpd_to_bfqgd(struct blkcg_policy_data *cpd)
484{
485 return cpd ? container_of(cpd, struct bfq_group_data, pd) : NULL;
486}
487
488static struct bfq_group_data *blkcg_to_bfqgd(struct blkcg *blkcg)
489{
490 return cpd_to_bfqgd(cpd: blkcg_to_cpd(blkcg, pol: &blkcg_policy_bfq));
491}
492
493static struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp)
494{
495 struct bfq_group_data *bgd;
496
497 bgd = kzalloc(sizeof(*bgd), gfp);
498 if (!bgd)
499 return NULL;
500
501 bgd->weight = CGROUP_WEIGHT_DFL;
502 return &bgd->pd;
503}
504
505static void bfq_cpd_free(struct blkcg_policy_data *cpd)
506{
507 kfree(objp: cpd_to_bfqgd(cpd));
508}
509
510static struct blkg_policy_data *bfq_pd_alloc(struct gendisk *disk,
511 struct blkcg *blkcg, gfp_t gfp)
512{
513 struct bfq_group *bfqg;
514
515 bfqg = kzalloc_node(sizeof(*bfqg), gfp, disk->node_id);
516 if (!bfqg)
517 return NULL;
518
519 if (bfqg_stats_init(stats: &bfqg->stats, gfp)) {
520 kfree(objp: bfqg);
521 return NULL;
522 }
523
524 /* see comments in bfq_bic_update_cgroup for why refcounting */
525 refcount_set(r: &bfqg->ref, n: 1);
526 return &bfqg->pd;
527}
528
529static void bfq_pd_init(struct blkg_policy_data *pd)
530{
531 struct blkcg_gq *blkg = pd_to_blkg(pd);
532 struct bfq_group *bfqg = blkg_to_bfqg(blkg);
533 struct bfq_data *bfqd = blkg->q->elevator->elevator_data;
534 struct bfq_entity *entity = &bfqg->entity;
535 struct bfq_group_data *d = blkcg_to_bfqgd(blkcg: blkg->blkcg);
536
537 entity->orig_weight = entity->weight = entity->new_weight = d->weight;
538 entity->my_sched_data = &bfqg->sched_data;
539 entity->last_bfqq_created = NULL;
540
541 bfqg->my_entity = entity; /*
542 * the root_group's will be set to NULL
543 * in bfq_init_queue()
544 */
545 bfqg->bfqd = bfqd;
546 bfqg->active_entities = 0;
547 bfqg->num_queues_with_pending_reqs = 0;
548 bfqg->rq_pos_tree = RB_ROOT;
549}
550
551static void bfq_pd_free(struct blkg_policy_data *pd)
552{
553 struct bfq_group *bfqg = pd_to_bfqg(pd);
554
555 bfqg_stats_exit(stats: &bfqg->stats);
556 bfqg_put(bfqg);
557}
558
559static void bfq_pd_reset_stats(struct blkg_policy_data *pd)
560{
561 struct bfq_group *bfqg = pd_to_bfqg(pd);
562
563 bfqg_stats_reset(stats: &bfqg->stats);
564}
565
566static void bfq_group_set_parent(struct bfq_group *bfqg,
567 struct bfq_group *parent)
568{
569 struct bfq_entity *entity;
570
571 entity = &bfqg->entity;
572 entity->parent = parent->my_entity;
573 entity->sched_data = &parent->sched_data;
574}
575
576static void bfq_link_bfqg(struct bfq_data *bfqd, struct bfq_group *bfqg)
577{
578 struct bfq_group *parent;
579 struct bfq_entity *entity;
580
581 /*
582 * Update chain of bfq_groups as we might be handling a leaf group
583 * which, along with some of its relatives, has not been hooked yet
584 * to the private hierarchy of BFQ.
585 */
586 entity = &bfqg->entity;
587 for_each_entity(entity) {
588 struct bfq_group *curr_bfqg = container_of(entity,
589 struct bfq_group, entity);
590 if (curr_bfqg != bfqd->root_group) {
591 parent = bfqg_parent(bfqg: curr_bfqg);
592 if (!parent)
593 parent = bfqd->root_group;
594 bfq_group_set_parent(bfqg: curr_bfqg, parent);
595 }
596 }
597}
598
599struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio)
600{
601 struct blkcg_gq *blkg = bio->bi_blkg;
602 struct bfq_group *bfqg;
603
604 while (blkg) {
605 if (!blkg->online) {
606 blkg = blkg->parent;
607 continue;
608 }
609 bfqg = blkg_to_bfqg(blkg);
610 if (bfqg->pd.online) {
611 bio_associate_blkg_from_css(bio, css: &blkg->blkcg->css);
612 return bfqg;
613 }
614 blkg = blkg->parent;
615 }
616 bio_associate_blkg_from_css(bio,
617 css: &bfqg_to_blkg(bfqg: bfqd->root_group)->blkcg->css);
618 return bfqd->root_group;
619}
620
621/**
622 * bfq_bfqq_move - migrate @bfqq to @bfqg.
623 * @bfqd: queue descriptor.
624 * @bfqq: the queue to move.
625 * @bfqg: the group to move to.
626 *
627 * Move @bfqq to @bfqg, deactivating it from its old group and reactivating
628 * it on the new one. Avoid putting the entity on the old group idle tree.
629 *
630 * Must be called under the scheduler lock, to make sure that the blkg
631 * owning @bfqg does not disappear (see comments in
632 * bfq_bic_update_cgroup on guaranteeing the consistency of blkg
633 * objects).
634 */
635void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
636 struct bfq_group *bfqg)
637{
638 struct bfq_entity *entity = &bfqq->entity;
639 struct bfq_group *old_parent = bfqq_group(bfqq);
640 bool has_pending_reqs = false;
641
642 /*
643 * No point to move bfqq to the same group, which can happen when
644 * root group is offlined
645 */
646 if (old_parent == bfqg)
647 return;
648
649 /*
650 * oom_bfqq is not allowed to move, oom_bfqq will hold ref to root_group
651 * until elevator exit.
652 */
653 if (bfqq == &bfqd->oom_bfqq)
654 return;
655 /*
656 * Get extra reference to prevent bfqq from being freed in
657 * next possible expire or deactivate.
658 */
659 bfqq->ref++;
660
661 if (entity->in_groups_with_pending_reqs) {
662 has_pending_reqs = true;
663 bfq_del_bfqq_in_groups_with_pending_reqs(bfqq);
664 }
665
666 /* If bfqq is empty, then bfq_bfqq_expire also invokes
667 * bfq_del_bfqq_busy, thereby removing bfqq and its entity
668 * from data structures related to current group. Otherwise we
669 * need to remove bfqq explicitly with bfq_deactivate_bfqq, as
670 * we do below.
671 */
672 if (bfqq == bfqd->in_service_queue)
673 bfq_bfqq_expire(bfqd, bfqq: bfqd->in_service_queue,
674 compensate: false, reason: BFQQE_PREEMPTED);
675
676 if (bfq_bfqq_busy(bfqq))
677 bfq_deactivate_bfqq(bfqd, bfqq, ins_into_idle_tree: false, expiration: false);
678 else if (entity->on_st_or_in_serv)
679 bfq_put_idle_entity(st: bfq_entity_service_tree(entity), entity);
680 bfqg_and_blkg_put(bfqg: old_parent);
681
682 bfq_reassign_last_bfqq(cur_bfqq: bfqq, NULL);
683 entity->parent = bfqg->my_entity;
684 entity->sched_data = &bfqg->sched_data;
685 /* pin down bfqg and its associated blkg */
686 bfqg_and_blkg_get(bfqg);
687
688 if (has_pending_reqs)
689 bfq_add_bfqq_in_groups_with_pending_reqs(bfqq);
690
691 if (bfq_bfqq_busy(bfqq)) {
692 if (unlikely(!bfqd->nonrot_with_queueing))
693 bfq_pos_tree_add_move(bfqd, bfqq);
694 bfq_activate_bfqq(bfqd, bfqq);
695 }
696
697 if (!bfqd->in_service_queue && !bfqd->tot_rq_in_driver)
698 bfq_schedule_dispatch(bfqd);
699 /* release extra ref taken above, bfqq may happen to be freed now */
700 bfq_put_queue(bfqq);
701}
702
703static void bfq_sync_bfqq_move(struct bfq_data *bfqd,
704 struct bfq_queue *sync_bfqq,
705 struct bfq_io_cq *bic,
706 struct bfq_group *bfqg,
707 unsigned int act_idx)
708{
709 struct bfq_queue *bfqq;
710
711 if (!sync_bfqq->new_bfqq && !bfq_bfqq_coop(bfqq: sync_bfqq)) {
712 /* We are the only user of this bfqq, just move it */
713 if (sync_bfqq->entity.sched_data != &bfqg->sched_data)
714 bfq_bfqq_move(bfqd, bfqq: sync_bfqq, bfqg);
715 return;
716 }
717
718 /*
719 * The queue was merged to a different queue. Check
720 * that the merge chain still belongs to the same
721 * cgroup.
722 */
723 for (bfqq = sync_bfqq; bfqq; bfqq = bfqq->new_bfqq)
724 if (bfqq->entity.sched_data != &bfqg->sched_data)
725 break;
726 if (bfqq) {
727 /*
728 * Some queue changed cgroup so the merge is not valid
729 * anymore. We cannot easily just cancel the merge (by
730 * clearing new_bfqq) as there may be other processes
731 * using this queue and holding refs to all queues
732 * below sync_bfqq->new_bfqq. Similarly if the merge
733 * already happened, we need to detach from bfqq now
734 * so that we cannot merge bio to a request from the
735 * old cgroup.
736 */
737 bfq_put_cooperator(bfqq: sync_bfqq);
738 bic_set_bfqq(bic, NULL, is_sync: true, actuator_idx: act_idx);
739 bfq_release_process_ref(bfqd, bfqq: sync_bfqq);
740 }
741}
742
743/**
744 * __bfq_bic_change_cgroup - move @bic to @bfqg.
745 * @bfqd: the queue descriptor.
746 * @bic: the bic to move.
747 * @bfqg: the group to move to.
748 *
749 * Move bic to blkcg, assuming that bfqd->lock is held; which makes
750 * sure that the reference to cgroup is valid across the call (see
751 * comments in bfq_bic_update_cgroup on this issue)
752 */
753static void __bfq_bic_change_cgroup(struct bfq_data *bfqd,
754 struct bfq_io_cq *bic,
755 struct bfq_group *bfqg)
756{
757 unsigned int act_idx;
758
759 for (act_idx = 0; act_idx < bfqd->num_actuators; act_idx++) {
760 struct bfq_queue *async_bfqq = bic_to_bfqq(bic, is_sync: false, actuator_idx: act_idx);
761 struct bfq_queue *sync_bfqq = bic_to_bfqq(bic, is_sync: true, actuator_idx: act_idx);
762
763 if (async_bfqq &&
764 async_bfqq->entity.sched_data != &bfqg->sched_data) {
765 bic_set_bfqq(bic, NULL, is_sync: false, actuator_idx: act_idx);
766 bfq_release_process_ref(bfqd, bfqq: async_bfqq);
767 }
768
769 if (sync_bfqq)
770 bfq_sync_bfqq_move(bfqd, sync_bfqq, bic, bfqg, act_idx);
771 }
772}
773
774void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio)
775{
776 struct bfq_data *bfqd = bic_to_bfqd(bic);
777 struct bfq_group *bfqg = bfq_bio_bfqg(bfqd, bio);
778 uint64_t serial_nr;
779
780 serial_nr = bfqg_to_blkg(bfqg)->blkcg->css.serial_nr;
781
782 /*
783 * Check whether blkcg has changed. The condition may trigger
784 * spuriously on a newly created cic but there's no harm.
785 */
786 if (unlikely(!bfqd) || likely(bic->blkcg_serial_nr == serial_nr))
787 return;
788
789 /*
790 * New cgroup for this process. Make sure it is linked to bfq internal
791 * cgroup hierarchy.
792 */
793 bfq_link_bfqg(bfqd, bfqg);
794 __bfq_bic_change_cgroup(bfqd, bic, bfqg);
795 bic->blkcg_serial_nr = serial_nr;
796}
797
798/**
799 * bfq_flush_idle_tree - deactivate any entity on the idle tree of @st.
800 * @st: the service tree being flushed.
801 */
802static void bfq_flush_idle_tree(struct bfq_service_tree *st)
803{
804 struct bfq_entity *entity = st->first_idle;
805
806 for (; entity ; entity = st->first_idle)
807 __bfq_deactivate_entity(entity, ins_into_idle_tree: false);
808}
809
810/**
811 * bfq_reparent_leaf_entity - move leaf entity to the root_group.
812 * @bfqd: the device data structure with the root group.
813 * @entity: the entity to move, if entity is a leaf; or the parent entity
814 * of an active leaf entity to move, if entity is not a leaf.
815 * @ioprio_class: I/O priority class to reparent.
816 */
817static void bfq_reparent_leaf_entity(struct bfq_data *bfqd,
818 struct bfq_entity *entity,
819 int ioprio_class)
820{
821 struct bfq_queue *bfqq;
822 struct bfq_entity *child_entity = entity;
823
824 while (child_entity->my_sched_data) { /* leaf not reached yet */
825 struct bfq_sched_data *child_sd = child_entity->my_sched_data;
826 struct bfq_service_tree *child_st = child_sd->service_tree +
827 ioprio_class;
828 struct rb_root *child_active = &child_st->active;
829
830 child_entity = bfq_entity_of(node: rb_first(root: child_active));
831
832 if (!child_entity)
833 child_entity = child_sd->in_service_entity;
834 }
835
836 bfqq = bfq_entity_to_bfqq(entity: child_entity);
837 bfq_bfqq_move(bfqd, bfqq, bfqg: bfqd->root_group);
838}
839
840/**
841 * bfq_reparent_active_queues - move to the root group all active queues.
842 * @bfqd: the device data structure with the root group.
843 * @bfqg: the group to move from.
844 * @st: the service tree to start the search from.
845 * @ioprio_class: I/O priority class to reparent.
846 */
847static void bfq_reparent_active_queues(struct bfq_data *bfqd,
848 struct bfq_group *bfqg,
849 struct bfq_service_tree *st,
850 int ioprio_class)
851{
852 struct rb_root *active = &st->active;
853 struct bfq_entity *entity;
854
855 while ((entity = bfq_entity_of(node: rb_first(root: active))))
856 bfq_reparent_leaf_entity(bfqd, entity, ioprio_class);
857
858 if (bfqg->sched_data.in_service_entity)
859 bfq_reparent_leaf_entity(bfqd,
860 entity: bfqg->sched_data.in_service_entity,
861 ioprio_class);
862}
863
864/**
865 * bfq_pd_offline - deactivate the entity associated with @pd,
866 * and reparent its children entities.
867 * @pd: descriptor of the policy going offline.
868 *
869 * blkio already grabs the queue_lock for us, so no need to use
870 * RCU-based magic
871 */
872static void bfq_pd_offline(struct blkg_policy_data *pd)
873{
874 struct bfq_service_tree *st;
875 struct bfq_group *bfqg = pd_to_bfqg(pd);
876 struct bfq_data *bfqd = bfqg->bfqd;
877 struct bfq_entity *entity = bfqg->my_entity;
878 unsigned long flags;
879 int i;
880
881 spin_lock_irqsave(&bfqd->lock, flags);
882
883 if (!entity) /* root group */
884 goto put_async_queues;
885
886 /*
887 * Empty all service_trees belonging to this group before
888 * deactivating the group itself.
889 */
890 for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) {
891 st = bfqg->sched_data.service_tree + i;
892
893 /*
894 * It may happen that some queues are still active
895 * (busy) upon group destruction (if the corresponding
896 * processes have been forced to terminate). We move
897 * all the leaf entities corresponding to these queues
898 * to the root_group.
899 * Also, it may happen that the group has an entity
900 * in service, which is disconnected from the active
901 * tree: it must be moved, too.
902 * There is no need to put the sync queues, as the
903 * scheduler has taken no reference.
904 */
905 bfq_reparent_active_queues(bfqd, bfqg, st, ioprio_class: i);
906
907 /*
908 * The idle tree may still contain bfq_queues
909 * belonging to exited task because they never
910 * migrated to a different cgroup from the one being
911 * destroyed now. In addition, even
912 * bfq_reparent_active_queues() may happen to add some
913 * entities to the idle tree. It happens if, in some
914 * of the calls to bfq_bfqq_move() performed by
915 * bfq_reparent_active_queues(), the queue to move is
916 * empty and gets expired.
917 */
918 bfq_flush_idle_tree(st);
919 }
920
921 __bfq_deactivate_entity(entity, ins_into_idle_tree: false);
922
923put_async_queues:
924 bfq_put_async_queues(bfqd, bfqg);
925
926 spin_unlock_irqrestore(lock: &bfqd->lock, flags);
927 /*
928 * @blkg is going offline and will be ignored by
929 * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so
930 * that they don't get lost. If IOs complete after this point, the
931 * stats for them will be lost. Oh well...
932 */
933 bfqg_stats_xfer_dead(bfqg);
934}
935
936void bfq_end_wr_async(struct bfq_data *bfqd)
937{
938 struct blkcg_gq *blkg;
939
940 list_for_each_entry(blkg, &bfqd->queue->blkg_list, q_node) {
941 struct bfq_group *bfqg = blkg_to_bfqg(blkg);
942
943 bfq_end_wr_async_queues(bfqd, bfqg);
944 }
945 bfq_end_wr_async_queues(bfqd, bfqg: bfqd->root_group);
946}
947
948static int bfq_io_show_weight_legacy(struct seq_file *sf, void *v)
949{
950 struct blkcg *blkcg = css_to_blkcg(css: seq_css(seq: sf));
951 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg);
952 unsigned int val = 0;
953
954 if (bfqgd)
955 val = bfqgd->weight;
956
957 seq_printf(m: sf, fmt: "%u\n", val);
958
959 return 0;
960}
961
962static u64 bfqg_prfill_weight_device(struct seq_file *sf,
963 struct blkg_policy_data *pd, int off)
964{
965 struct bfq_group *bfqg = pd_to_bfqg(pd);
966
967 if (!bfqg->entity.dev_weight)
968 return 0;
969 return __blkg_prfill_u64(sf, pd, v: bfqg->entity.dev_weight);
970}
971
972static int bfq_io_show_weight(struct seq_file *sf, void *v)
973{
974 struct blkcg *blkcg = css_to_blkcg(css: seq_css(seq: sf));
975 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg);
976
977 seq_printf(m: sf, fmt: "default %u\n", bfqgd->weight);
978 blkcg_print_blkgs(sf, blkcg, prfill: bfqg_prfill_weight_device,
979 pol: &blkcg_policy_bfq, data: 0, show_total: false);
980 return 0;
981}
982
983static void bfq_group_set_weight(struct bfq_group *bfqg, u64 weight, u64 dev_weight)
984{
985 weight = dev_weight ?: weight;
986
987 bfqg->entity.dev_weight = dev_weight;
988 /*
989 * Setting the prio_changed flag of the entity
990 * to 1 with new_weight == weight would re-set
991 * the value of the weight to its ioprio mapping.
992 * Set the flag only if necessary.
993 */
994 if ((unsigned short)weight != bfqg->entity.new_weight) {
995 bfqg->entity.new_weight = (unsigned short)weight;
996 /*
997 * Make sure that the above new value has been
998 * stored in bfqg->entity.new_weight before
999 * setting the prio_changed flag. In fact,
1000 * this flag may be read asynchronously (in
1001 * critical sections protected by a different
1002 * lock than that held here), and finding this
1003 * flag set may cause the execution of the code
1004 * for updating parameters whose value may
1005 * depend also on bfqg->entity.new_weight (in
1006 * __bfq_entity_update_weight_prio).
1007 * This barrier makes sure that the new value
1008 * of bfqg->entity.new_weight is correctly
1009 * seen in that code.
1010 */
1011 smp_wmb();
1012 bfqg->entity.prio_changed = 1;
1013 }
1014}
1015
1016static int bfq_io_set_weight_legacy(struct cgroup_subsys_state *css,
1017 struct cftype *cftype,
1018 u64 val)
1019{
1020 struct blkcg *blkcg = css_to_blkcg(css);
1021 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg);
1022 struct blkcg_gq *blkg;
1023 int ret = -ERANGE;
1024
1025 if (val < BFQ_MIN_WEIGHT || val > BFQ_MAX_WEIGHT)
1026 return ret;
1027
1028 ret = 0;
1029 spin_lock_irq(lock: &blkcg->lock);
1030 bfqgd->weight = (unsigned short)val;
1031 hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
1032 struct bfq_group *bfqg = blkg_to_bfqg(blkg);
1033
1034 if (bfqg)
1035 bfq_group_set_weight(bfqg, weight: val, dev_weight: 0);
1036 }
1037 spin_unlock_irq(lock: &blkcg->lock);
1038
1039 return ret;
1040}
1041
1042static ssize_t bfq_io_set_device_weight(struct kernfs_open_file *of,
1043 char *buf, size_t nbytes,
1044 loff_t off)
1045{
1046 int ret;
1047 struct blkg_conf_ctx ctx;
1048 struct blkcg *blkcg = css_to_blkcg(css: of_css(of));
1049 struct bfq_group *bfqg;
1050 u64 v;
1051
1052 blkg_conf_init(ctx: &ctx, input: buf);
1053
1054 ret = blkg_conf_prep(blkcg, pol: &blkcg_policy_bfq, ctx: &ctx);
1055 if (ret)
1056 goto out;
1057
1058 if (sscanf(ctx.body, "%llu", &v) == 1) {
1059 /* require "default" on dfl */
1060 ret = -ERANGE;
1061 if (!v)
1062 goto out;
1063 } else if (!strcmp(strim(ctx.body), "default")) {
1064 v = 0;
1065 } else {
1066 ret = -EINVAL;
1067 goto out;
1068 }
1069
1070 bfqg = blkg_to_bfqg(blkg: ctx.blkg);
1071
1072 ret = -ERANGE;
1073 if (!v || (v >= BFQ_MIN_WEIGHT && v <= BFQ_MAX_WEIGHT)) {
1074 bfq_group_set_weight(bfqg, weight: bfqg->entity.weight, dev_weight: v);
1075 ret = 0;
1076 }
1077out:
1078 blkg_conf_exit(ctx: &ctx);
1079 return ret ?: nbytes;
1080}
1081
1082static ssize_t bfq_io_set_weight(struct kernfs_open_file *of,
1083 char *buf, size_t nbytes,
1084 loff_t off)
1085{
1086 char *endp;
1087 int ret;
1088 u64 v;
1089
1090 buf = strim(buf);
1091
1092 /* "WEIGHT" or "default WEIGHT" sets the default weight */
1093 v = simple_strtoull(buf, &endp, 0);
1094 if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) {
1095 ret = bfq_io_set_weight_legacy(css: of_css(of), NULL, val: v);
1096 return ret ?: nbytes;
1097 }
1098
1099 return bfq_io_set_device_weight(of, buf, nbytes, off);
1100}
1101
1102static int bfqg_print_rwstat(struct seq_file *sf, void *v)
1103{
1104 blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)), prfill: blkg_prfill_rwstat,
1105 pol: &blkcg_policy_bfq, data: seq_cft(seq: sf)->private, show_total: true);
1106 return 0;
1107}
1108
1109static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf,
1110 struct blkg_policy_data *pd, int off)
1111{
1112 struct blkg_rwstat_sample sum;
1113
1114 blkg_rwstat_recursive_sum(blkg: pd_to_blkg(pd), pol: &blkcg_policy_bfq, off, sum: &sum);
1115 return __blkg_prfill_rwstat(sf, pd, rwstat: &sum);
1116}
1117
1118static int bfqg_print_rwstat_recursive(struct seq_file *sf, void *v)
1119{
1120 blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)),
1121 prfill: bfqg_prfill_rwstat_recursive, pol: &blkcg_policy_bfq,
1122 data: seq_cft(seq: sf)->private, show_total: true);
1123 return 0;
1124}
1125
1126#ifdef CONFIG_BFQ_CGROUP_DEBUG
1127static int bfqg_print_stat(struct seq_file *sf, void *v)
1128{
1129 blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)), prfill: blkg_prfill_stat,
1130 pol: &blkcg_policy_bfq, data: seq_cft(seq: sf)->private, show_total: false);
1131 return 0;
1132}
1133
1134static u64 bfqg_prfill_stat_recursive(struct seq_file *sf,
1135 struct blkg_policy_data *pd, int off)
1136{
1137 struct blkcg_gq *blkg = pd_to_blkg(pd);
1138 struct blkcg_gq *pos_blkg;
1139 struct cgroup_subsys_state *pos_css;
1140 u64 sum = 0;
1141
1142 lockdep_assert_held(&blkg->q->queue_lock);
1143
1144 rcu_read_lock();
1145 blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
1146 struct bfq_stat *stat;
1147
1148 if (!pos_blkg->online)
1149 continue;
1150
1151 stat = (void *)blkg_to_pd(blkg: pos_blkg, pol: &blkcg_policy_bfq) + off;
1152 sum += bfq_stat_read(stat) + atomic64_read(v: &stat->aux_cnt);
1153 }
1154 rcu_read_unlock();
1155
1156 return __blkg_prfill_u64(sf, pd, v: sum);
1157}
1158
1159static int bfqg_print_stat_recursive(struct seq_file *sf, void *v)
1160{
1161 blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)),
1162 prfill: bfqg_prfill_stat_recursive, pol: &blkcg_policy_bfq,
1163 data: seq_cft(seq: sf)->private, show_total: false);
1164 return 0;
1165}
1166
1167static u64 bfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd,
1168 int off)
1169{
1170 struct bfq_group *bfqg = blkg_to_bfqg(blkg: pd->blkg);
1171 u64 sum = blkg_rwstat_total(rwstat: &bfqg->stats.bytes);
1172
1173 return __blkg_prfill_u64(sf, pd, v: sum >> 9);
1174}
1175
1176static int bfqg_print_stat_sectors(struct seq_file *sf, void *v)
1177{
1178 blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)),
1179 prfill: bfqg_prfill_sectors, pol: &blkcg_policy_bfq, data: 0, show_total: false);
1180 return 0;
1181}
1182
1183static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf,
1184 struct blkg_policy_data *pd, int off)
1185{
1186 struct blkg_rwstat_sample tmp;
1187
1188 blkg_rwstat_recursive_sum(blkg: pd->blkg, pol: &blkcg_policy_bfq,
1189 offsetof(struct bfq_group, stats.bytes), sum: &tmp);
1190
1191 return __blkg_prfill_u64(sf, pd,
1192 v: (tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]) >> 9);
1193}
1194
1195static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v)
1196{
1197 blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)),
1198 prfill: bfqg_prfill_sectors_recursive, pol: &blkcg_policy_bfq, data: 0,
1199 show_total: false);
1200 return 0;
1201}
1202
1203static u64 bfqg_prfill_avg_queue_size(struct seq_file *sf,
1204 struct blkg_policy_data *pd, int off)
1205{
1206 struct bfq_group *bfqg = pd_to_bfqg(pd);
1207 u64 samples = bfq_stat_read(stat: &bfqg->stats.avg_queue_size_samples);
1208 u64 v = 0;
1209
1210 if (samples) {
1211 v = bfq_stat_read(stat: &bfqg->stats.avg_queue_size_sum);
1212 v = div64_u64(dividend: v, divisor: samples);
1213 }
1214 __blkg_prfill_u64(sf, pd, v);
1215 return 0;
1216}
1217
1218/* print avg_queue_size */
1219static int bfqg_print_avg_queue_size(struct seq_file *sf, void *v)
1220{
1221 blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)),
1222 prfill: bfqg_prfill_avg_queue_size, pol: &blkcg_policy_bfq,
1223 data: 0, show_total: false);
1224 return 0;
1225}
1226#endif /* CONFIG_BFQ_CGROUP_DEBUG */
1227
1228struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
1229{
1230 int ret;
1231
1232 ret = blkcg_activate_policy(disk: bfqd->queue->disk, pol: &blkcg_policy_bfq);
1233 if (ret)
1234 return NULL;
1235
1236 return blkg_to_bfqg(blkg: bfqd->queue->root_blkg);
1237}
1238
1239struct blkcg_policy blkcg_policy_bfq = {
1240 .dfl_cftypes = bfq_blkg_files,
1241 .legacy_cftypes = bfq_blkcg_legacy_files,
1242
1243 .cpd_alloc_fn = bfq_cpd_alloc,
1244 .cpd_free_fn = bfq_cpd_free,
1245
1246 .pd_alloc_fn = bfq_pd_alloc,
1247 .pd_init_fn = bfq_pd_init,
1248 .pd_offline_fn = bfq_pd_offline,
1249 .pd_free_fn = bfq_pd_free,
1250 .pd_reset_stats_fn = bfq_pd_reset_stats,
1251};
1252
1253struct cftype bfq_blkcg_legacy_files[] = {
1254 {
1255 .name = "bfq.weight",
1256 .flags = CFTYPE_NOT_ON_ROOT,
1257 .seq_show = bfq_io_show_weight_legacy,
1258 .write_u64 = bfq_io_set_weight_legacy,
1259 },
1260 {
1261 .name = "bfq.weight_device",
1262 .flags = CFTYPE_NOT_ON_ROOT,
1263 .seq_show = bfq_io_show_weight,
1264 .write = bfq_io_set_weight,
1265 },
1266
1267 /* statistics, covers only the tasks in the bfqg */
1268 {
1269 .name = "bfq.io_service_bytes",
1270 .private = offsetof(struct bfq_group, stats.bytes),
1271 .seq_show = bfqg_print_rwstat,
1272 },
1273 {
1274 .name = "bfq.io_serviced",
1275 .private = offsetof(struct bfq_group, stats.ios),
1276 .seq_show = bfqg_print_rwstat,
1277 },
1278#ifdef CONFIG_BFQ_CGROUP_DEBUG
1279 {
1280 .name = "bfq.time",
1281 .private = offsetof(struct bfq_group, stats.time),
1282 .seq_show = bfqg_print_stat,
1283 },
1284 {
1285 .name = "bfq.sectors",
1286 .seq_show = bfqg_print_stat_sectors,
1287 },
1288 {
1289 .name = "bfq.io_service_time",
1290 .private = offsetof(struct bfq_group, stats.service_time),
1291 .seq_show = bfqg_print_rwstat,
1292 },
1293 {
1294 .name = "bfq.io_wait_time",
1295 .private = offsetof(struct bfq_group, stats.wait_time),
1296 .seq_show = bfqg_print_rwstat,
1297 },
1298 {
1299 .name = "bfq.io_merged",
1300 .private = offsetof(struct bfq_group, stats.merged),
1301 .seq_show = bfqg_print_rwstat,
1302 },
1303 {
1304 .name = "bfq.io_queued",
1305 .private = offsetof(struct bfq_group, stats.queued),
1306 .seq_show = bfqg_print_rwstat,
1307 },
1308#endif /* CONFIG_BFQ_CGROUP_DEBUG */
1309
1310 /* the same statistics which cover the bfqg and its descendants */
1311 {
1312 .name = "bfq.io_service_bytes_recursive",
1313 .private = offsetof(struct bfq_group, stats.bytes),
1314 .seq_show = bfqg_print_rwstat_recursive,
1315 },
1316 {
1317 .name = "bfq.io_serviced_recursive",
1318 .private = offsetof(struct bfq_group, stats.ios),
1319 .seq_show = bfqg_print_rwstat_recursive,
1320 },
1321#ifdef CONFIG_BFQ_CGROUP_DEBUG
1322 {
1323 .name = "bfq.time_recursive",
1324 .private = offsetof(struct bfq_group, stats.time),
1325 .seq_show = bfqg_print_stat_recursive,
1326 },
1327 {
1328 .name = "bfq.sectors_recursive",
1329 .seq_show = bfqg_print_stat_sectors_recursive,
1330 },
1331 {
1332 .name = "bfq.io_service_time_recursive",
1333 .private = offsetof(struct bfq_group, stats.service_time),
1334 .seq_show = bfqg_print_rwstat_recursive,
1335 },
1336 {
1337 .name = "bfq.io_wait_time_recursive",
1338 .private = offsetof(struct bfq_group, stats.wait_time),
1339 .seq_show = bfqg_print_rwstat_recursive,
1340 },
1341 {
1342 .name = "bfq.io_merged_recursive",
1343 .private = offsetof(struct bfq_group, stats.merged),
1344 .seq_show = bfqg_print_rwstat_recursive,
1345 },
1346 {
1347 .name = "bfq.io_queued_recursive",
1348 .private = offsetof(struct bfq_group, stats.queued),
1349 .seq_show = bfqg_print_rwstat_recursive,
1350 },
1351 {
1352 .name = "bfq.avg_queue_size",
1353 .seq_show = bfqg_print_avg_queue_size,
1354 },
1355 {
1356 .name = "bfq.group_wait_time",
1357 .private = offsetof(struct bfq_group, stats.group_wait_time),
1358 .seq_show = bfqg_print_stat,
1359 },
1360 {
1361 .name = "bfq.idle_time",
1362 .private = offsetof(struct bfq_group, stats.idle_time),
1363 .seq_show = bfqg_print_stat,
1364 },
1365 {
1366 .name = "bfq.empty_time",
1367 .private = offsetof(struct bfq_group, stats.empty_time),
1368 .seq_show = bfqg_print_stat,
1369 },
1370 {
1371 .name = "bfq.dequeue",
1372 .private = offsetof(struct bfq_group, stats.dequeue),
1373 .seq_show = bfqg_print_stat,
1374 },
1375#endif /* CONFIG_BFQ_CGROUP_DEBUG */
1376 { } /* terminate */
1377};
1378
1379struct cftype bfq_blkg_files[] = {
1380 {
1381 .name = "bfq.weight",
1382 .flags = CFTYPE_NOT_ON_ROOT,
1383 .seq_show = bfq_io_show_weight,
1384 .write = bfq_io_set_weight,
1385 },
1386 {} /* terminate */
1387};
1388
1389#else /* CONFIG_BFQ_GROUP_IOSCHED */
1390
1391void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
1392 struct bfq_group *bfqg) {}
1393
1394void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg)
1395{
1396 struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity);
1397
1398 entity->weight = entity->new_weight;
1399 entity->orig_weight = entity->new_weight;
1400 if (bfqq) {
1401 bfqq->ioprio = bfqq->new_ioprio;
1402 bfqq->ioprio_class = bfqq->new_ioprio_class;
1403 }
1404 entity->sched_data = &bfqg->sched_data;
1405}
1406
1407void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) {}
1408
1409void bfq_end_wr_async(struct bfq_data *bfqd)
1410{
1411 bfq_end_wr_async_queues(bfqd, bfqd->root_group);
1412}
1413
1414struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio)
1415{
1416 return bfqd->root_group;
1417}
1418
1419struct bfq_group *bfqq_group(struct bfq_queue *bfqq)
1420{
1421 return bfqq->bfqd->root_group;
1422}
1423
1424void bfqg_and_blkg_put(struct bfq_group *bfqg) {}
1425
1426struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
1427{
1428 struct bfq_group *bfqg;
1429 int i;
1430
1431 bfqg = kmalloc_node(sizeof(*bfqg), GFP_KERNEL | __GFP_ZERO, node);
1432 if (!bfqg)
1433 return NULL;
1434
1435 for (i = 0; i < BFQ_IOPRIO_CLASSES; i++)
1436 bfqg->sched_data.service_tree[i] = BFQ_SERVICE_TREE_INIT;
1437
1438 return bfqg;
1439}
1440#endif /* CONFIG_BFQ_GROUP_IOSCHED */
1441

source code of linux/block/bfq-cgroup.c