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 |
19 | static 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 | |
31 | static 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 | */ |
44 | static 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 | */ |
53 | static 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 | */ |
62 | static 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 | */ |
75 | static 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 | */ |
90 | static 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 */ |
97 | enum bfqg_stats_flags { |
98 | BFQG_stats_waiting = 0, |
99 | BFQG_stats_idling, |
100 | BFQG_stats_empty, |
101 | }; |
102 | |
103 | #define BFQG_FLAG_FNS(name) \ |
104 | static void bfqg_stats_mark_##name(struct bfqg_stats *stats) \ |
105 | { \ |
106 | stats->flags |= (1 << BFQG_stats_##name); \ |
107 | } \ |
108 | static void bfqg_stats_clear_##name(struct bfqg_stats *stats) \ |
109 | { \ |
110 | stats->flags &= ~(1 << BFQG_stats_##name); \ |
111 | } \ |
112 | static int bfqg_stats_##name(struct bfqg_stats *stats) \ |
113 | { \ |
114 | return (stats->flags & (1 << BFQG_stats_##name)) != 0; \ |
115 | } \ |
116 | |
117 | BFQG_FLAG_FNS(waiting) |
118 | BFQG_FLAG_FNS(idling) |
119 | BFQG_FLAG_FNS(empty) |
120 | #undef BFQG_FLAG_FNS |
121 | |
122 | /* This should be called with the scheduler lock held. */ |
123 | static 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 = ktime_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. */ |
138 | static 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 = ktime_get_ns(); |
148 | bfqg_stats_mark_waiting(stats); |
149 | } |
150 | |
151 | /* This should be called with the scheduler lock held. */ |
152 | static 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 = ktime_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 | |
166 | void bfqg_stats_update_dequeue(struct bfq_group *bfqg) |
167 | { |
168 | bfq_stat_add(stat: &bfqg->stats.dequeue, val: 1); |
169 | } |
170 | |
171 | void 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 = ktime_get_ns(); |
187 | bfqg_stats_mark_empty(stats); |
188 | } |
189 | |
190 | void 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 = ktime_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 | |
204 | void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg) |
205 | { |
206 | struct bfqg_stats *stats = &bfqg->stats; |
207 | |
208 | stats->start_idle_time = ktime_get_ns(); |
209 | bfqg_stats_mark_idling(stats); |
210 | } |
211 | |
212 | void 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 | |
222 | void 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 | |
231 | void 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 | |
236 | void 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 | |
241 | void 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 = ktime_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 | |
257 | void bfqg_stats_update_io_remove(struct bfq_group *bfqg, blk_opf_t opf) { } |
258 | void bfqg_stats_update_io_merged(struct bfq_group *bfqg, blk_opf_t opf) { } |
259 | void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns, |
260 | u64 io_start_time_ns, blk_opf_t opf) { } |
261 | void bfqg_stats_update_dequeue(struct bfq_group *bfqg) { } |
262 | void 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 | |
274 | static 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 | |
279 | struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg) |
280 | { |
281 | return pd_to_blkg(pd: &bfqg->pd); |
282 | } |
283 | |
284 | static 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 | |
296 | static 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 | |
303 | struct 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 | |
317 | static void bfqg_get(struct bfq_group *bfqg) |
318 | { |
319 | refcount_inc(r: &bfqg->ref); |
320 | } |
321 | |
322 | static void bfqg_put(struct bfq_group *bfqg) |
323 | { |
324 | if (refcount_dec_and_test(r: &bfqg->ref)) |
325 | kfree(objp: bfqg); |
326 | } |
327 | |
328 | static 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 | |
336 | void bfqg_and_blkg_put(struct bfq_group *bfqg) |
337 | { |
338 | blkg_put(blkg: bfqg_to_blkg(bfqg)); |
339 | |
340 | bfqg_put(bfqg); |
341 | } |
342 | |
343 | void 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 */ |
355 | static 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 */ |
373 | static 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: &from->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 | */ |
399 | static 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 | |
417 | void 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 | |
436 | static 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 | |
455 | static 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 | |
478 | error: |
479 | bfqg_stats_exit(stats); |
480 | return -ENOMEM; |
481 | } |
482 | |
483 | static 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 | |
488 | static 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 | |
493 | static struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp) |
494 | { |
495 | struct bfq_group_data *bgd; |
496 | |
497 | bgd = kzalloc(size: sizeof(*bgd), flags: gfp); |
498 | if (!bgd) |
499 | return NULL; |
500 | |
501 | bgd->weight = CGROUP_WEIGHT_DFL; |
502 | return &bgd->pd; |
503 | } |
504 | |
505 | static void bfq_cpd_free(struct blkcg_policy_data *cpd) |
506 | { |
507 | kfree(objp: cpd_to_bfqgd(cpd)); |
508 | } |
509 | |
510 | static 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(size: sizeof(*bfqg), flags: gfp, node: 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 | |
529 | static 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 | |
551 | static 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 | |
559 | static 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 | |
566 | static 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 | |
576 | static 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 | |
599 | struct 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 | */ |
635 | void 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 | if (entity->parent && |
683 | entity->parent->last_bfqq_created == bfqq) |
684 | entity->parent->last_bfqq_created = NULL; |
685 | else if (bfqd->last_bfqq_created == bfqq) |
686 | bfqd->last_bfqq_created = NULL; |
687 | |
688 | entity->parent = bfqg->my_entity; |
689 | entity->sched_data = &bfqg->sched_data; |
690 | /* pin down bfqg and its associated blkg */ |
691 | bfqg_and_blkg_get(bfqg); |
692 | |
693 | if (has_pending_reqs) |
694 | bfq_add_bfqq_in_groups_with_pending_reqs(bfqq); |
695 | |
696 | if (bfq_bfqq_busy(bfqq)) { |
697 | if (unlikely(!bfqd->nonrot_with_queueing)) |
698 | bfq_pos_tree_add_move(bfqd, bfqq); |
699 | bfq_activate_bfqq(bfqd, bfqq); |
700 | } |
701 | |
702 | if (!bfqd->in_service_queue && !bfqd->tot_rq_in_driver) |
703 | bfq_schedule_dispatch(bfqd); |
704 | /* release extra ref taken above, bfqq may happen to be freed now */ |
705 | bfq_put_queue(bfqq); |
706 | } |
707 | |
708 | static void bfq_sync_bfqq_move(struct bfq_data *bfqd, |
709 | struct bfq_queue *sync_bfqq, |
710 | struct bfq_io_cq *bic, |
711 | struct bfq_group *bfqg, |
712 | unsigned int act_idx) |
713 | { |
714 | struct bfq_queue *bfqq; |
715 | |
716 | if (!sync_bfqq->new_bfqq && !bfq_bfqq_coop(bfqq: sync_bfqq)) { |
717 | /* We are the only user of this bfqq, just move it */ |
718 | if (sync_bfqq->entity.sched_data != &bfqg->sched_data) |
719 | bfq_bfqq_move(bfqd, bfqq: sync_bfqq, bfqg); |
720 | return; |
721 | } |
722 | |
723 | /* |
724 | * The queue was merged to a different queue. Check |
725 | * that the merge chain still belongs to the same |
726 | * cgroup. |
727 | */ |
728 | for (bfqq = sync_bfqq; bfqq; bfqq = bfqq->new_bfqq) |
729 | if (bfqq->entity.sched_data != &bfqg->sched_data) |
730 | break; |
731 | if (bfqq) { |
732 | /* |
733 | * Some queue changed cgroup so the merge is not valid |
734 | * anymore. We cannot easily just cancel the merge (by |
735 | * clearing new_bfqq) as there may be other processes |
736 | * using this queue and holding refs to all queues |
737 | * below sync_bfqq->new_bfqq. Similarly if the merge |
738 | * already happened, we need to detach from bfqq now |
739 | * so that we cannot merge bio to a request from the |
740 | * old cgroup. |
741 | */ |
742 | bfq_put_cooperator(bfqq: sync_bfqq); |
743 | bic_set_bfqq(bic, NULL, is_sync: true, actuator_idx: act_idx); |
744 | bfq_release_process_ref(bfqd, bfqq: sync_bfqq); |
745 | } |
746 | } |
747 | |
748 | /** |
749 | * __bfq_bic_change_cgroup - move @bic to @bfqg. |
750 | * @bfqd: the queue descriptor. |
751 | * @bic: the bic to move. |
752 | * @bfqg: the group to move to. |
753 | * |
754 | * Move bic to blkcg, assuming that bfqd->lock is held; which makes |
755 | * sure that the reference to cgroup is valid across the call (see |
756 | * comments in bfq_bic_update_cgroup on this issue) |
757 | */ |
758 | static void __bfq_bic_change_cgroup(struct bfq_data *bfqd, |
759 | struct bfq_io_cq *bic, |
760 | struct bfq_group *bfqg) |
761 | { |
762 | unsigned int act_idx; |
763 | |
764 | for (act_idx = 0; act_idx < bfqd->num_actuators; act_idx++) { |
765 | struct bfq_queue *async_bfqq = bic_to_bfqq(bic, is_sync: false, actuator_idx: act_idx); |
766 | struct bfq_queue *sync_bfqq = bic_to_bfqq(bic, is_sync: true, actuator_idx: act_idx); |
767 | |
768 | if (async_bfqq && |
769 | async_bfqq->entity.sched_data != &bfqg->sched_data) { |
770 | bic_set_bfqq(bic, NULL, is_sync: false, actuator_idx: act_idx); |
771 | bfq_release_process_ref(bfqd, bfqq: async_bfqq); |
772 | } |
773 | |
774 | if (sync_bfqq) |
775 | bfq_sync_bfqq_move(bfqd, sync_bfqq, bic, bfqg, act_idx); |
776 | } |
777 | } |
778 | |
779 | void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) |
780 | { |
781 | struct bfq_data *bfqd = bic_to_bfqd(bic); |
782 | struct bfq_group *bfqg = bfq_bio_bfqg(bfqd, bio); |
783 | uint64_t serial_nr; |
784 | |
785 | serial_nr = bfqg_to_blkg(bfqg)->blkcg->css.serial_nr; |
786 | |
787 | /* |
788 | * Check whether blkcg has changed. The condition may trigger |
789 | * spuriously on a newly created cic but there's no harm. |
790 | */ |
791 | if (unlikely(!bfqd) || likely(bic->blkcg_serial_nr == serial_nr)) |
792 | return; |
793 | |
794 | /* |
795 | * New cgroup for this process. Make sure it is linked to bfq internal |
796 | * cgroup hierarchy. |
797 | */ |
798 | bfq_link_bfqg(bfqd, bfqg); |
799 | __bfq_bic_change_cgroup(bfqd, bic, bfqg); |
800 | /* |
801 | * Update blkg_path for bfq_log_* functions. We cache this |
802 | * path, and update it here, for the following |
803 | * reasons. Operations on blkg objects in blk-cgroup are |
804 | * protected with the request_queue lock, and not with the |
805 | * lock that protects the instances of this scheduler |
806 | * (bfqd->lock). This exposes BFQ to the following sort of |
807 | * race. |
808 | * |
809 | * The blkg_lookup performed in bfq_get_queue, protected |
810 | * through rcu, may happen to return the address of a copy of |
811 | * the original blkg. If this is the case, then the |
812 | * bfqg_and_blkg_get performed in bfq_get_queue, to pin down |
813 | * the blkg, is useless: it does not prevent blk-cgroup code |
814 | * from destroying both the original blkg and all objects |
815 | * directly or indirectly referred by the copy of the |
816 | * blkg. |
817 | * |
818 | * On the bright side, destroy operations on a blkg invoke, as |
819 | * a first step, hooks of the scheduler associated with the |
820 | * blkg. And these hooks are executed with bfqd->lock held for |
821 | * BFQ. As a consequence, for any blkg associated with the |
822 | * request queue this instance of the scheduler is attached |
823 | * to, we are guaranteed that such a blkg is not destroyed, and |
824 | * that all the pointers it contains are consistent, while we |
825 | * are holding bfqd->lock. A blkg_lookup performed with |
826 | * bfqd->lock held then returns a fully consistent blkg, which |
827 | * remains consistent until this lock is held. |
828 | * |
829 | * Thanks to the last fact, and to the fact that: (1) bfqg has |
830 | * been obtained through a blkg_lookup in the above |
831 | * assignment, and (2) bfqd->lock is being held, here we can |
832 | * safely use the policy data for the involved blkg (i.e., the |
833 | * field bfqg->pd) to get to the blkg associated with bfqg, |
834 | * and then we can safely use any field of blkg. After we |
835 | * release bfqd->lock, even just getting blkg through this |
836 | * bfqg may cause dangling references to be traversed, as |
837 | * bfqg->pd may not exist any more. |
838 | * |
839 | * In view of the above facts, here we cache, in the bfqg, any |
840 | * blkg data we may need for this bic, and for its associated |
841 | * bfq_queue. As of now, we need to cache only the path of the |
842 | * blkg, which is used in the bfq_log_* functions. |
843 | * |
844 | * Finally, note that bfqg itself needs to be protected from |
845 | * destruction on the blkg_free of the original blkg (which |
846 | * invokes bfq_pd_free). We use an additional private |
847 | * refcounter for bfqg, to let it disappear only after no |
848 | * bfq_queue refers to it any longer. |
849 | */ |
850 | blkg_path(blkg: bfqg_to_blkg(bfqg), buf: bfqg->blkg_path, buflen: sizeof(bfqg->blkg_path)); |
851 | bic->blkcg_serial_nr = serial_nr; |
852 | } |
853 | |
854 | /** |
855 | * bfq_flush_idle_tree - deactivate any entity on the idle tree of @st. |
856 | * @st: the service tree being flushed. |
857 | */ |
858 | static void bfq_flush_idle_tree(struct bfq_service_tree *st) |
859 | { |
860 | struct bfq_entity *entity = st->first_idle; |
861 | |
862 | for (; entity ; entity = st->first_idle) |
863 | __bfq_deactivate_entity(entity, ins_into_idle_tree: false); |
864 | } |
865 | |
866 | /** |
867 | * bfq_reparent_leaf_entity - move leaf entity to the root_group. |
868 | * @bfqd: the device data structure with the root group. |
869 | * @entity: the entity to move, if entity is a leaf; or the parent entity |
870 | * of an active leaf entity to move, if entity is not a leaf. |
871 | * @ioprio_class: I/O priority class to reparent. |
872 | */ |
873 | static void bfq_reparent_leaf_entity(struct bfq_data *bfqd, |
874 | struct bfq_entity *entity, |
875 | int ioprio_class) |
876 | { |
877 | struct bfq_queue *bfqq; |
878 | struct bfq_entity *child_entity = entity; |
879 | |
880 | while (child_entity->my_sched_data) { /* leaf not reached yet */ |
881 | struct bfq_sched_data *child_sd = child_entity->my_sched_data; |
882 | struct bfq_service_tree *child_st = child_sd->service_tree + |
883 | ioprio_class; |
884 | struct rb_root *child_active = &child_st->active; |
885 | |
886 | child_entity = bfq_entity_of(node: rb_first(child_active)); |
887 | |
888 | if (!child_entity) |
889 | child_entity = child_sd->in_service_entity; |
890 | } |
891 | |
892 | bfqq = bfq_entity_to_bfqq(entity: child_entity); |
893 | bfq_bfqq_move(bfqd, bfqq, bfqg: bfqd->root_group); |
894 | } |
895 | |
896 | /** |
897 | * bfq_reparent_active_queues - move to the root group all active queues. |
898 | * @bfqd: the device data structure with the root group. |
899 | * @bfqg: the group to move from. |
900 | * @st: the service tree to start the search from. |
901 | * @ioprio_class: I/O priority class to reparent. |
902 | */ |
903 | static void bfq_reparent_active_queues(struct bfq_data *bfqd, |
904 | struct bfq_group *bfqg, |
905 | struct bfq_service_tree *st, |
906 | int ioprio_class) |
907 | { |
908 | struct rb_root *active = &st->active; |
909 | struct bfq_entity *entity; |
910 | |
911 | while ((entity = bfq_entity_of(node: rb_first(active)))) |
912 | bfq_reparent_leaf_entity(bfqd, entity, ioprio_class); |
913 | |
914 | if (bfqg->sched_data.in_service_entity) |
915 | bfq_reparent_leaf_entity(bfqd, |
916 | entity: bfqg->sched_data.in_service_entity, |
917 | ioprio_class); |
918 | } |
919 | |
920 | /** |
921 | * bfq_pd_offline - deactivate the entity associated with @pd, |
922 | * and reparent its children entities. |
923 | * @pd: descriptor of the policy going offline. |
924 | * |
925 | * blkio already grabs the queue_lock for us, so no need to use |
926 | * RCU-based magic |
927 | */ |
928 | static void bfq_pd_offline(struct blkg_policy_data *pd) |
929 | { |
930 | struct bfq_service_tree *st; |
931 | struct bfq_group *bfqg = pd_to_bfqg(pd); |
932 | struct bfq_data *bfqd = bfqg->bfqd; |
933 | struct bfq_entity *entity = bfqg->my_entity; |
934 | unsigned long flags; |
935 | int i; |
936 | |
937 | spin_lock_irqsave(&bfqd->lock, flags); |
938 | |
939 | if (!entity) /* root group */ |
940 | goto put_async_queues; |
941 | |
942 | /* |
943 | * Empty all service_trees belonging to this group before |
944 | * deactivating the group itself. |
945 | */ |
946 | for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) { |
947 | st = bfqg->sched_data.service_tree + i; |
948 | |
949 | /* |
950 | * It may happen that some queues are still active |
951 | * (busy) upon group destruction (if the corresponding |
952 | * processes have been forced to terminate). We move |
953 | * all the leaf entities corresponding to these queues |
954 | * to the root_group. |
955 | * Also, it may happen that the group has an entity |
956 | * in service, which is disconnected from the active |
957 | * tree: it must be moved, too. |
958 | * There is no need to put the sync queues, as the |
959 | * scheduler has taken no reference. |
960 | */ |
961 | bfq_reparent_active_queues(bfqd, bfqg, st, ioprio_class: i); |
962 | |
963 | /* |
964 | * The idle tree may still contain bfq_queues |
965 | * belonging to exited task because they never |
966 | * migrated to a different cgroup from the one being |
967 | * destroyed now. In addition, even |
968 | * bfq_reparent_active_queues() may happen to add some |
969 | * entities to the idle tree. It happens if, in some |
970 | * of the calls to bfq_bfqq_move() performed by |
971 | * bfq_reparent_active_queues(), the queue to move is |
972 | * empty and gets expired. |
973 | */ |
974 | bfq_flush_idle_tree(st); |
975 | } |
976 | |
977 | __bfq_deactivate_entity(entity, ins_into_idle_tree: false); |
978 | |
979 | put_async_queues: |
980 | bfq_put_async_queues(bfqd, bfqg); |
981 | |
982 | spin_unlock_irqrestore(lock: &bfqd->lock, flags); |
983 | /* |
984 | * @blkg is going offline and will be ignored by |
985 | * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so |
986 | * that they don't get lost. If IOs complete after this point, the |
987 | * stats for them will be lost. Oh well... |
988 | */ |
989 | bfqg_stats_xfer_dead(bfqg); |
990 | } |
991 | |
992 | void bfq_end_wr_async(struct bfq_data *bfqd) |
993 | { |
994 | struct blkcg_gq *blkg; |
995 | |
996 | list_for_each_entry(blkg, &bfqd->queue->blkg_list, q_node) { |
997 | struct bfq_group *bfqg = blkg_to_bfqg(blkg); |
998 | |
999 | bfq_end_wr_async_queues(bfqd, bfqg); |
1000 | } |
1001 | bfq_end_wr_async_queues(bfqd, bfqg: bfqd->root_group); |
1002 | } |
1003 | |
1004 | static int bfq_io_show_weight_legacy(struct seq_file *sf, void *v) |
1005 | { |
1006 | struct blkcg *blkcg = css_to_blkcg(css: seq_css(seq: sf)); |
1007 | struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); |
1008 | unsigned int val = 0; |
1009 | |
1010 | if (bfqgd) |
1011 | val = bfqgd->weight; |
1012 | |
1013 | seq_printf(m: sf, fmt: "%u\n" , val); |
1014 | |
1015 | return 0; |
1016 | } |
1017 | |
1018 | static u64 bfqg_prfill_weight_device(struct seq_file *sf, |
1019 | struct blkg_policy_data *pd, int off) |
1020 | { |
1021 | struct bfq_group *bfqg = pd_to_bfqg(pd); |
1022 | |
1023 | if (!bfqg->entity.dev_weight) |
1024 | return 0; |
1025 | return __blkg_prfill_u64(sf, pd, v: bfqg->entity.dev_weight); |
1026 | } |
1027 | |
1028 | static int bfq_io_show_weight(struct seq_file *sf, void *v) |
1029 | { |
1030 | struct blkcg *blkcg = css_to_blkcg(css: seq_css(seq: sf)); |
1031 | struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); |
1032 | |
1033 | seq_printf(m: sf, fmt: "default %u\n" , bfqgd->weight); |
1034 | blkcg_print_blkgs(sf, blkcg, prfill: bfqg_prfill_weight_device, |
1035 | pol: &blkcg_policy_bfq, data: 0, show_total: false); |
1036 | return 0; |
1037 | } |
1038 | |
1039 | static void bfq_group_set_weight(struct bfq_group *bfqg, u64 weight, u64 dev_weight) |
1040 | { |
1041 | weight = dev_weight ?: weight; |
1042 | |
1043 | bfqg->entity.dev_weight = dev_weight; |
1044 | /* |
1045 | * Setting the prio_changed flag of the entity |
1046 | * to 1 with new_weight == weight would re-set |
1047 | * the value of the weight to its ioprio mapping. |
1048 | * Set the flag only if necessary. |
1049 | */ |
1050 | if ((unsigned short)weight != bfqg->entity.new_weight) { |
1051 | bfqg->entity.new_weight = (unsigned short)weight; |
1052 | /* |
1053 | * Make sure that the above new value has been |
1054 | * stored in bfqg->entity.new_weight before |
1055 | * setting the prio_changed flag. In fact, |
1056 | * this flag may be read asynchronously (in |
1057 | * critical sections protected by a different |
1058 | * lock than that held here), and finding this |
1059 | * flag set may cause the execution of the code |
1060 | * for updating parameters whose value may |
1061 | * depend also on bfqg->entity.new_weight (in |
1062 | * __bfq_entity_update_weight_prio). |
1063 | * This barrier makes sure that the new value |
1064 | * of bfqg->entity.new_weight is correctly |
1065 | * seen in that code. |
1066 | */ |
1067 | smp_wmb(); |
1068 | bfqg->entity.prio_changed = 1; |
1069 | } |
1070 | } |
1071 | |
1072 | static int bfq_io_set_weight_legacy(struct cgroup_subsys_state *css, |
1073 | struct cftype *cftype, |
1074 | u64 val) |
1075 | { |
1076 | struct blkcg *blkcg = css_to_blkcg(css); |
1077 | struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); |
1078 | struct blkcg_gq *blkg; |
1079 | int ret = -ERANGE; |
1080 | |
1081 | if (val < BFQ_MIN_WEIGHT || val > BFQ_MAX_WEIGHT) |
1082 | return ret; |
1083 | |
1084 | ret = 0; |
1085 | spin_lock_irq(lock: &blkcg->lock); |
1086 | bfqgd->weight = (unsigned short)val; |
1087 | hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { |
1088 | struct bfq_group *bfqg = blkg_to_bfqg(blkg); |
1089 | |
1090 | if (bfqg) |
1091 | bfq_group_set_weight(bfqg, weight: val, dev_weight: 0); |
1092 | } |
1093 | spin_unlock_irq(lock: &blkcg->lock); |
1094 | |
1095 | return ret; |
1096 | } |
1097 | |
1098 | static ssize_t bfq_io_set_device_weight(struct kernfs_open_file *of, |
1099 | char *buf, size_t nbytes, |
1100 | loff_t off) |
1101 | { |
1102 | int ret; |
1103 | struct blkg_conf_ctx ctx; |
1104 | struct blkcg *blkcg = css_to_blkcg(css: of_css(of)); |
1105 | struct bfq_group *bfqg; |
1106 | u64 v; |
1107 | |
1108 | blkg_conf_init(ctx: &ctx, input: buf); |
1109 | |
1110 | ret = blkg_conf_prep(blkcg, pol: &blkcg_policy_bfq, ctx: &ctx); |
1111 | if (ret) |
1112 | goto out; |
1113 | |
1114 | if (sscanf(ctx.body, "%llu" , &v) == 1) { |
1115 | /* require "default" on dfl */ |
1116 | ret = -ERANGE; |
1117 | if (!v) |
1118 | goto out; |
1119 | } else if (!strcmp(strim(ctx.body), "default" )) { |
1120 | v = 0; |
1121 | } else { |
1122 | ret = -EINVAL; |
1123 | goto out; |
1124 | } |
1125 | |
1126 | bfqg = blkg_to_bfqg(blkg: ctx.blkg); |
1127 | |
1128 | ret = -ERANGE; |
1129 | if (!v || (v >= BFQ_MIN_WEIGHT && v <= BFQ_MAX_WEIGHT)) { |
1130 | bfq_group_set_weight(bfqg, weight: bfqg->entity.weight, dev_weight: v); |
1131 | ret = 0; |
1132 | } |
1133 | out: |
1134 | blkg_conf_exit(ctx: &ctx); |
1135 | return ret ?: nbytes; |
1136 | } |
1137 | |
1138 | static ssize_t bfq_io_set_weight(struct kernfs_open_file *of, |
1139 | char *buf, size_t nbytes, |
1140 | loff_t off) |
1141 | { |
1142 | char *endp; |
1143 | int ret; |
1144 | u64 v; |
1145 | |
1146 | buf = strim(buf); |
1147 | |
1148 | /* "WEIGHT" or "default WEIGHT" sets the default weight */ |
1149 | v = simple_strtoull(buf, &endp, 0); |
1150 | if (*endp == '\0' || sscanf(buf, "default %llu" , &v) == 1) { |
1151 | ret = bfq_io_set_weight_legacy(css: of_css(of), NULL, val: v); |
1152 | return ret ?: nbytes; |
1153 | } |
1154 | |
1155 | return bfq_io_set_device_weight(of, buf, nbytes, off); |
1156 | } |
1157 | |
1158 | static int bfqg_print_rwstat(struct seq_file *sf, void *v) |
1159 | { |
1160 | blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)), prfill: blkg_prfill_rwstat, |
1161 | pol: &blkcg_policy_bfq, data: seq_cft(seq: sf)->private, show_total: true); |
1162 | return 0; |
1163 | } |
1164 | |
1165 | static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf, |
1166 | struct blkg_policy_data *pd, int off) |
1167 | { |
1168 | struct blkg_rwstat_sample sum; |
1169 | |
1170 | blkg_rwstat_recursive_sum(blkg: pd_to_blkg(pd), pol: &blkcg_policy_bfq, off, sum: &sum); |
1171 | return __blkg_prfill_rwstat(sf, pd, rwstat: &sum); |
1172 | } |
1173 | |
1174 | static int bfqg_print_rwstat_recursive(struct seq_file *sf, void *v) |
1175 | { |
1176 | blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)), |
1177 | prfill: bfqg_prfill_rwstat_recursive, pol: &blkcg_policy_bfq, |
1178 | data: seq_cft(seq: sf)->private, show_total: true); |
1179 | return 0; |
1180 | } |
1181 | |
1182 | #ifdef CONFIG_BFQ_CGROUP_DEBUG |
1183 | static int bfqg_print_stat(struct seq_file *sf, void *v) |
1184 | { |
1185 | blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)), prfill: blkg_prfill_stat, |
1186 | pol: &blkcg_policy_bfq, data: seq_cft(seq: sf)->private, show_total: false); |
1187 | return 0; |
1188 | } |
1189 | |
1190 | static u64 bfqg_prfill_stat_recursive(struct seq_file *sf, |
1191 | struct blkg_policy_data *pd, int off) |
1192 | { |
1193 | struct blkcg_gq *blkg = pd_to_blkg(pd); |
1194 | struct blkcg_gq *pos_blkg; |
1195 | struct cgroup_subsys_state *pos_css; |
1196 | u64 sum = 0; |
1197 | |
1198 | lockdep_assert_held(&blkg->q->queue_lock); |
1199 | |
1200 | rcu_read_lock(); |
1201 | blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { |
1202 | struct bfq_stat *stat; |
1203 | |
1204 | if (!pos_blkg->online) |
1205 | continue; |
1206 | |
1207 | stat = (void *)blkg_to_pd(blkg: pos_blkg, pol: &blkcg_policy_bfq) + off; |
1208 | sum += bfq_stat_read(stat) + atomic64_read(v: &stat->aux_cnt); |
1209 | } |
1210 | rcu_read_unlock(); |
1211 | |
1212 | return __blkg_prfill_u64(sf, pd, v: sum); |
1213 | } |
1214 | |
1215 | static int bfqg_print_stat_recursive(struct seq_file *sf, void *v) |
1216 | { |
1217 | blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)), |
1218 | prfill: bfqg_prfill_stat_recursive, pol: &blkcg_policy_bfq, |
1219 | data: seq_cft(seq: sf)->private, show_total: false); |
1220 | return 0; |
1221 | } |
1222 | |
1223 | static u64 bfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd, |
1224 | int off) |
1225 | { |
1226 | struct bfq_group *bfqg = blkg_to_bfqg(blkg: pd->blkg); |
1227 | u64 sum = blkg_rwstat_total(rwstat: &bfqg->stats.bytes); |
1228 | |
1229 | return __blkg_prfill_u64(sf, pd, v: sum >> 9); |
1230 | } |
1231 | |
1232 | static int bfqg_print_stat_sectors(struct seq_file *sf, void *v) |
1233 | { |
1234 | blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)), |
1235 | prfill: bfqg_prfill_sectors, pol: &blkcg_policy_bfq, data: 0, show_total: false); |
1236 | return 0; |
1237 | } |
1238 | |
1239 | static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf, |
1240 | struct blkg_policy_data *pd, int off) |
1241 | { |
1242 | struct blkg_rwstat_sample tmp; |
1243 | |
1244 | blkg_rwstat_recursive_sum(blkg: pd->blkg, pol: &blkcg_policy_bfq, |
1245 | offsetof(struct bfq_group, stats.bytes), sum: &tmp); |
1246 | |
1247 | return __blkg_prfill_u64(sf, pd, |
1248 | v: (tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]) >> 9); |
1249 | } |
1250 | |
1251 | static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v) |
1252 | { |
1253 | blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)), |
1254 | prfill: bfqg_prfill_sectors_recursive, pol: &blkcg_policy_bfq, data: 0, |
1255 | show_total: false); |
1256 | return 0; |
1257 | } |
1258 | |
1259 | static u64 bfqg_prfill_avg_queue_size(struct seq_file *sf, |
1260 | struct blkg_policy_data *pd, int off) |
1261 | { |
1262 | struct bfq_group *bfqg = pd_to_bfqg(pd); |
1263 | u64 samples = bfq_stat_read(stat: &bfqg->stats.avg_queue_size_samples); |
1264 | u64 v = 0; |
1265 | |
1266 | if (samples) { |
1267 | v = bfq_stat_read(stat: &bfqg->stats.avg_queue_size_sum); |
1268 | v = div64_u64(dividend: v, divisor: samples); |
1269 | } |
1270 | __blkg_prfill_u64(sf, pd, v); |
1271 | return 0; |
1272 | } |
1273 | |
1274 | /* print avg_queue_size */ |
1275 | static int bfqg_print_avg_queue_size(struct seq_file *sf, void *v) |
1276 | { |
1277 | blkcg_print_blkgs(sf, blkcg: css_to_blkcg(css: seq_css(seq: sf)), |
1278 | prfill: bfqg_prfill_avg_queue_size, pol: &blkcg_policy_bfq, |
1279 | data: 0, show_total: false); |
1280 | return 0; |
1281 | } |
1282 | #endif /* CONFIG_BFQ_CGROUP_DEBUG */ |
1283 | |
1284 | struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node) |
1285 | { |
1286 | int ret; |
1287 | |
1288 | ret = blkcg_activate_policy(disk: bfqd->queue->disk, pol: &blkcg_policy_bfq); |
1289 | if (ret) |
1290 | return NULL; |
1291 | |
1292 | return blkg_to_bfqg(blkg: bfqd->queue->root_blkg); |
1293 | } |
1294 | |
1295 | struct blkcg_policy blkcg_policy_bfq = { |
1296 | .dfl_cftypes = bfq_blkg_files, |
1297 | .legacy_cftypes = bfq_blkcg_legacy_files, |
1298 | |
1299 | .cpd_alloc_fn = bfq_cpd_alloc, |
1300 | .cpd_free_fn = bfq_cpd_free, |
1301 | |
1302 | .pd_alloc_fn = bfq_pd_alloc, |
1303 | .pd_init_fn = bfq_pd_init, |
1304 | .pd_offline_fn = bfq_pd_offline, |
1305 | .pd_free_fn = bfq_pd_free, |
1306 | .pd_reset_stats_fn = bfq_pd_reset_stats, |
1307 | }; |
1308 | |
1309 | struct cftype bfq_blkcg_legacy_files[] = { |
1310 | { |
1311 | .name = "bfq.weight" , |
1312 | .flags = CFTYPE_NOT_ON_ROOT, |
1313 | .seq_show = bfq_io_show_weight_legacy, |
1314 | .write_u64 = bfq_io_set_weight_legacy, |
1315 | }, |
1316 | { |
1317 | .name = "bfq.weight_device" , |
1318 | .flags = CFTYPE_NOT_ON_ROOT, |
1319 | .seq_show = bfq_io_show_weight, |
1320 | .write = bfq_io_set_weight, |
1321 | }, |
1322 | |
1323 | /* statistics, covers only the tasks in the bfqg */ |
1324 | { |
1325 | .name = "bfq.io_service_bytes" , |
1326 | .private = offsetof(struct bfq_group, stats.bytes), |
1327 | .seq_show = bfqg_print_rwstat, |
1328 | }, |
1329 | { |
1330 | .name = "bfq.io_serviced" , |
1331 | .private = offsetof(struct bfq_group, stats.ios), |
1332 | .seq_show = bfqg_print_rwstat, |
1333 | }, |
1334 | #ifdef CONFIG_BFQ_CGROUP_DEBUG |
1335 | { |
1336 | .name = "bfq.time" , |
1337 | .private = offsetof(struct bfq_group, stats.time), |
1338 | .seq_show = bfqg_print_stat, |
1339 | }, |
1340 | { |
1341 | .name = "bfq.sectors" , |
1342 | .seq_show = bfqg_print_stat_sectors, |
1343 | }, |
1344 | { |
1345 | .name = "bfq.io_service_time" , |
1346 | .private = offsetof(struct bfq_group, stats.service_time), |
1347 | .seq_show = bfqg_print_rwstat, |
1348 | }, |
1349 | { |
1350 | .name = "bfq.io_wait_time" , |
1351 | .private = offsetof(struct bfq_group, stats.wait_time), |
1352 | .seq_show = bfqg_print_rwstat, |
1353 | }, |
1354 | { |
1355 | .name = "bfq.io_merged" , |
1356 | .private = offsetof(struct bfq_group, stats.merged), |
1357 | .seq_show = bfqg_print_rwstat, |
1358 | }, |
1359 | { |
1360 | .name = "bfq.io_queued" , |
1361 | .private = offsetof(struct bfq_group, stats.queued), |
1362 | .seq_show = bfqg_print_rwstat, |
1363 | }, |
1364 | #endif /* CONFIG_BFQ_CGROUP_DEBUG */ |
1365 | |
1366 | /* the same statistics which cover the bfqg and its descendants */ |
1367 | { |
1368 | .name = "bfq.io_service_bytes_recursive" , |
1369 | .private = offsetof(struct bfq_group, stats.bytes), |
1370 | .seq_show = bfqg_print_rwstat_recursive, |
1371 | }, |
1372 | { |
1373 | .name = "bfq.io_serviced_recursive" , |
1374 | .private = offsetof(struct bfq_group, stats.ios), |
1375 | .seq_show = bfqg_print_rwstat_recursive, |
1376 | }, |
1377 | #ifdef CONFIG_BFQ_CGROUP_DEBUG |
1378 | { |
1379 | .name = "bfq.time_recursive" , |
1380 | .private = offsetof(struct bfq_group, stats.time), |
1381 | .seq_show = bfqg_print_stat_recursive, |
1382 | }, |
1383 | { |
1384 | .name = "bfq.sectors_recursive" , |
1385 | .seq_show = bfqg_print_stat_sectors_recursive, |
1386 | }, |
1387 | { |
1388 | .name = "bfq.io_service_time_recursive" , |
1389 | .private = offsetof(struct bfq_group, stats.service_time), |
1390 | .seq_show = bfqg_print_rwstat_recursive, |
1391 | }, |
1392 | { |
1393 | .name = "bfq.io_wait_time_recursive" , |
1394 | .private = offsetof(struct bfq_group, stats.wait_time), |
1395 | .seq_show = bfqg_print_rwstat_recursive, |
1396 | }, |
1397 | { |
1398 | .name = "bfq.io_merged_recursive" , |
1399 | .private = offsetof(struct bfq_group, stats.merged), |
1400 | .seq_show = bfqg_print_rwstat_recursive, |
1401 | }, |
1402 | { |
1403 | .name = "bfq.io_queued_recursive" , |
1404 | .private = offsetof(struct bfq_group, stats.queued), |
1405 | .seq_show = bfqg_print_rwstat_recursive, |
1406 | }, |
1407 | { |
1408 | .name = "bfq.avg_queue_size" , |
1409 | .seq_show = bfqg_print_avg_queue_size, |
1410 | }, |
1411 | { |
1412 | .name = "bfq.group_wait_time" , |
1413 | .private = offsetof(struct bfq_group, stats.group_wait_time), |
1414 | .seq_show = bfqg_print_stat, |
1415 | }, |
1416 | { |
1417 | .name = "bfq.idle_time" , |
1418 | .private = offsetof(struct bfq_group, stats.idle_time), |
1419 | .seq_show = bfqg_print_stat, |
1420 | }, |
1421 | { |
1422 | .name = "bfq.empty_time" , |
1423 | .private = offsetof(struct bfq_group, stats.empty_time), |
1424 | .seq_show = bfqg_print_stat, |
1425 | }, |
1426 | { |
1427 | .name = "bfq.dequeue" , |
1428 | .private = offsetof(struct bfq_group, stats.dequeue), |
1429 | .seq_show = bfqg_print_stat, |
1430 | }, |
1431 | #endif /* CONFIG_BFQ_CGROUP_DEBUG */ |
1432 | { } /* terminate */ |
1433 | }; |
1434 | |
1435 | struct cftype bfq_blkg_files[] = { |
1436 | { |
1437 | .name = "bfq.weight" , |
1438 | .flags = CFTYPE_NOT_ON_ROOT, |
1439 | .seq_show = bfq_io_show_weight, |
1440 | .write = bfq_io_set_weight, |
1441 | }, |
1442 | {} /* terminate */ |
1443 | }; |
1444 | |
1445 | #else /* CONFIG_BFQ_GROUP_IOSCHED */ |
1446 | |
1447 | void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, |
1448 | struct bfq_group *bfqg) {} |
1449 | |
1450 | void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg) |
1451 | { |
1452 | struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); |
1453 | |
1454 | entity->weight = entity->new_weight; |
1455 | entity->orig_weight = entity->new_weight; |
1456 | if (bfqq) { |
1457 | bfqq->ioprio = bfqq->new_ioprio; |
1458 | bfqq->ioprio_class = bfqq->new_ioprio_class; |
1459 | } |
1460 | entity->sched_data = &bfqg->sched_data; |
1461 | } |
1462 | |
1463 | void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) {} |
1464 | |
1465 | void bfq_end_wr_async(struct bfq_data *bfqd) |
1466 | { |
1467 | bfq_end_wr_async_queues(bfqd, bfqd->root_group); |
1468 | } |
1469 | |
1470 | struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio) |
1471 | { |
1472 | return bfqd->root_group; |
1473 | } |
1474 | |
1475 | struct bfq_group *bfqq_group(struct bfq_queue *bfqq) |
1476 | { |
1477 | return bfqq->bfqd->root_group; |
1478 | } |
1479 | |
1480 | void bfqg_and_blkg_put(struct bfq_group *bfqg) {} |
1481 | |
1482 | struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node) |
1483 | { |
1484 | struct bfq_group *bfqg; |
1485 | int i; |
1486 | |
1487 | bfqg = kmalloc_node(sizeof(*bfqg), GFP_KERNEL | __GFP_ZERO, node); |
1488 | if (!bfqg) |
1489 | return NULL; |
1490 | |
1491 | for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) |
1492 | bfqg->sched_data.service_tree[i] = BFQ_SERVICE_TREE_INIT; |
1493 | |
1494 | return bfqg; |
1495 | } |
1496 | #endif /* CONFIG_BFQ_GROUP_IOSCHED */ |
1497 | |