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(&stat->aux_cnt, 0); 28 return 0; 29} 30 31static void bfq_stat_exit(struct bfq_stat *stat) 32{ 33 percpu_counter_destroy(&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(&stat->cpu_cnt, 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(&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(&stat->cpu_cnt, 0); 65 atomic64_set(&stat->aux_cnt, 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(bfq_stat_read(from) + atomic64_read(&from->aux_cnt), 79 &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, bfq_stat_read((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(&stats->group_wait_time, 133 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(&stats->empty_time, 162 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(&bfqg->stats.dequeue, 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(&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(&stats->idle_time, 199 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(&stats->avg_queue_size_sum, 217 blkg_rwstat_total(&stats->queued)); 218 bfq_stat_add(&stats->avg_queue_size_samples, 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(&bfqg->stats.queued, opf, 1); 226 bfqg_stats_end_empty_time(&bfqg->stats); 227 if (!(bfqq == bfqg->bfqd->in_service_queue)) 228 bfqg_stats_set_start_group_wait_time(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(&bfqg->stats.queued, opf, -1); 234} 235 236void bfqg_stats_update_io_merged(struct bfq_group *bfqg, blk_opf_t opf) 237{ 238 blkg_rwstat_add(&bfqg->stats.merged, opf, 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(&stats->service_time, opf, 249 now - io_start_time_ns); 250 if (io_start_time_ns > start_time_ns) 251 blkg_rwstat_add(&stats->wait_time, opf, 252 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(&bfqg->pd); 282} 283 284static struct bfq_group *blkg_to_bfqg(struct blkcg_gq *blkg) 285{ 286 return pd_to_bfqg(blkg_to_pd(blkg, &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(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(&bfqg->ref); 320} 321 322static void bfqg_put(struct bfq_group *bfqg) 323{ 324 if (refcount_dec_and_test(&bfqg->ref)) 325 kfree(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(bfqg_to_blkg(bfqg)); 334} 335 336void bfqg_and_blkg_put(struct bfq_group *bfqg) 337{ 338 blkg_put(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(rq->bio->bi_blkg); 346 347 if (!bfqg) 348 return; 349 350 blkg_rwstat_add(&bfqg->stats.bytes, rq->cmd_flags, blk_rq_bytes(rq)); 351 blkg_rwstat_add(&bfqg->stats.ios, rq->cmd_flags, 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(&stats->merged); 360 blkg_rwstat_reset(&stats->service_time); 361 blkg_rwstat_reset(&stats->wait_time); 362 bfq_stat_reset(&stats->time); 363 bfq_stat_reset(&stats->avg_queue_size_sum); 364 bfq_stat_reset(&stats->avg_queue_size_samples); 365 bfq_stat_reset(&stats->dequeue); 366 bfq_stat_reset(&stats->group_wait_time); 367 bfq_stat_reset(&stats->idle_time); 368 bfq_stat_reset(&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->merged, &from->merged); 381 blkg_rwstat_add_aux(&to->service_time, &from->service_time); 382 blkg_rwstat_add_aux(&to->wait_time, &from->wait_time); 383 bfq_stat_add_aux(&from->time, &from->time); 384 bfq_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum); 385 bfq_stat_add_aux(&to->avg_queue_size_samples, 386 &from->avg_queue_size_samples); 387 bfq_stat_add_aux(&to->dequeue, &from->dequeue); 388 bfq_stat_add_aux(&to->group_wait_time, &from->group_wait_time); 389 bfq_stat_add_aux(&to->idle_time, &from->idle_time); 390 bfq_stat_add_aux(&to->empty_time, &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(&parent->stats, &bfqg->stats); 414 bfqg_stats_reset(&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(&stats->bytes); 439 blkg_rwstat_exit(&stats->ios); 440#ifdef CONFIG_BFQ_CGROUP_DEBUG 441 blkg_rwstat_exit(&stats->merged); 442 blkg_rwstat_exit(&stats->service_time); 443 blkg_rwstat_exit(&stats->wait_time); 444 blkg_rwstat_exit(&stats->queued); 445 bfq_stat_exit(&stats->time); 446 bfq_stat_exit(&stats->avg_queue_size_sum); 447 bfq_stat_exit(&stats->avg_queue_size_samples); 448 bfq_stat_exit(&stats->dequeue); 449 bfq_stat_exit(&stats->group_wait_time); 450 bfq_stat_exit(&stats->idle_time); 451 bfq_stat_exit(&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(&stats->bytes, gfp) || 458 blkg_rwstat_init(&stats->ios, gfp)) 459 goto error; 460 461#ifdef CONFIG_BFQ_CGROUP_DEBUG 462 if (blkg_rwstat_init(&stats->merged, gfp) || 463 blkg_rwstat_init(&stats->service_time, gfp) || 464 blkg_rwstat_init(&stats->wait_time, gfp) || 465 blkg_rwstat_init(&stats->queued, gfp) || 466 bfq_stat_init(&stats->time, gfp) || 467 bfq_stat_init(&stats->avg_queue_size_sum, gfp) || 468 bfq_stat_init(&stats->avg_queue_size_samples, gfp) || 469 bfq_stat_init(&stats->dequeue, gfp) || 470 bfq_stat_init(&stats->group_wait_time, gfp) || 471 bfq_stat_init(&stats->idle_time, gfp) || 472 bfq_stat_init(&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(blkcg_to_cpd(blkcg, &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(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(&bfqg->stats, gfp)) { 520 kfree(bfqg); 521 return NULL; 522 } 523 524 /* see comments in bfq_bic_update_cgroup for why refcounting */ 525 refcount_set(&bfqg->ref, 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(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(&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(&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(curr_bfqg); 592 if (!parent) 593 parent = bfqd->root_group; 594 bfq_group_set_parent(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, &blkg->blkcg->css); 612 return bfqg; 613 } 614 blkg = blkg->parent; 615 } 616 bio_associate_blkg_from_css(bio, 617 &bfqg_to_blkg(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, bfqd->in_service_queue, 674 false, BFQQE_PREEMPTED); 675 676 if (bfq_bfqq_busy(bfqq)) 677 bfq_deactivate_bfqq(bfqd, bfqq, false, false); 678 else if (entity->on_st_or_in_serv) 679 bfq_put_idle_entity(bfq_entity_service_tree(entity), entity); 680 bfqg_and_blkg_put(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 708static 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(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, 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(sync_bfqq); 743 bic_set_bfqq(bic, NULL, true, act_idx); 744 bfq_release_process_ref(bfqd, 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 */ 758static 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, false, act_idx); 766 struct bfq_queue *sync_bfqq = bic_to_bfqq(bic, true, act_idx); 767 768 if (async_bfqq && 769 async_bfqq->entity.sched_data != &bfqg->sched_data) { 770 bic_set_bfqq(bic, NULL, false, act_idx); 771 bfq_release_process_ref(bfqd, async_bfqq); 772 } 773 774 if (sync_bfqq) 775 bfq_sync_bfqq_move(bfqd, sync_bfqq, bic, bfqg, act_idx); 776 } 777} 778 779void 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(bfqg_to_blkg(bfqg), bfqg->blkg_path, 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 */ 858static 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, 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 */ 873static 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(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(child_entity); 893 bfq_bfqq_move(bfqd, bfqq, 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 */ 903static 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(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 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 */ 928static 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, 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, false); 978 979put_async_queues: 980 bfq_put_async_queues(bfqd, bfqg); 981 982 spin_unlock_irqrestore(&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 992void 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, bfqd->root_group); 1002} 1003 1004static int bfq_io_show_weight_legacy(struct seq_file *sf, void *v) 1005{ 1006 struct blkcg *blkcg = css_to_blkcg(seq_css(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(sf, "%u\n", val); 1014 1015 return 0; 1016} 1017 1018static 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, bfqg->entity.dev_weight); 1026} 1027 1028static int bfq_io_show_weight(struct seq_file *sf, void *v) 1029{ 1030 struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); 1031 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); 1032 1033 seq_printf(sf, "default %u\n", bfqgd->weight); 1034 blkcg_print_blkgs(sf, blkcg, bfqg_prfill_weight_device, 1035 &blkcg_policy_bfq, 0, false); 1036 return 0; 1037} 1038 1039static 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 1072static 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(&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, val, 0); 1092 } 1093 spin_unlock_irq(&blkcg->lock); 1094 1095 return ret; 1096} 1097 1098static 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(of_css(of)); 1105 struct bfq_group *bfqg; 1106 u64 v; 1107 1108 blkg_conf_init(&ctx, buf); 1109 1110 ret = blkg_conf_prep(blkcg, &blkcg_policy_bfq, &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(ctx.blkg); 1127 1128 ret = -ERANGE; 1129 if (!v || (v >= BFQ_MIN_WEIGHT && v <= BFQ_MAX_WEIGHT)) { 1130 bfq_group_set_weight(bfqg, bfqg->entity.weight, v); 1131 ret = 0; 1132 } 1133out: 1134 blkg_conf_exit(&ctx); 1135 return ret ?: nbytes; 1136} 1137 1138static 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(of_css(of), NULL, v); 1152 return ret ?: nbytes; 1153 } 1154 1155 return bfq_io_set_device_weight(of, buf, nbytes, off); 1156} 1157 1158static int bfqg_print_rwstat(struct seq_file *sf, void *v) 1159{ 1160 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat, 1161 &blkcg_policy_bfq, seq_cft(sf)->private, true); 1162 return 0; 1163} 1164 1165static 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(pd_to_blkg(pd), &blkcg_policy_bfq, off, &sum); 1171 return __blkg_prfill_rwstat(sf, pd, &sum); 1172} 1173 1174static int bfqg_print_rwstat_recursive(struct seq_file *sf, void *v) 1175{ 1176 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1177 bfqg_prfill_rwstat_recursive, &blkcg_policy_bfq, 1178 seq_cft(sf)->private, true); 1179 return 0; 1180} 1181 1182#ifdef CONFIG_BFQ_CGROUP_DEBUG 1183static int bfqg_print_stat(struct seq_file *sf, void *v) 1184{ 1185 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat, 1186 &blkcg_policy_bfq, seq_cft(sf)->private, false); 1187 return 0; 1188} 1189 1190static 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(pos_blkg, &blkcg_policy_bfq) + off; 1208 sum += bfq_stat_read(stat) + atomic64_read(&stat->aux_cnt); 1209 } 1210 rcu_read_unlock(); 1211 1212 return __blkg_prfill_u64(sf, pd, sum); 1213} 1214 1215static int bfqg_print_stat_recursive(struct seq_file *sf, void *v) 1216{ 1217 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1218 bfqg_prfill_stat_recursive, &blkcg_policy_bfq, 1219 seq_cft(sf)->private, false); 1220 return 0; 1221} 1222 1223static 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(pd->blkg); 1227 u64 sum = blkg_rwstat_total(&bfqg->stats.bytes); 1228 1229 return __blkg_prfill_u64(sf, pd, sum >> 9); 1230} 1231 1232static int bfqg_print_stat_sectors(struct seq_file *sf, void *v) 1233{ 1234 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1235 bfqg_prfill_sectors, &blkcg_policy_bfq, 0, false); 1236 return 0; 1237} 1238 1239static 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(pd->blkg, &blkcg_policy_bfq, 1245 offsetof(struct bfq_group, stats.bytes), &tmp); 1246 1247 return __blkg_prfill_u64(sf, pd, 1248 (tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]) >> 9); 1249} 1250 1251static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v) 1252{ 1253 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1254 bfqg_prfill_sectors_recursive, &blkcg_policy_bfq, 0, 1255 false); 1256 return 0; 1257} 1258 1259static 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(&bfqg->stats.avg_queue_size_samples); 1264 u64 v = 0; 1265 1266 if (samples) { 1267 v = bfq_stat_read(&bfqg->stats.avg_queue_size_sum); 1268 v = div64_u64(v, samples); 1269 } 1270 __blkg_prfill_u64(sf, pd, v); 1271 return 0; 1272} 1273 1274/* print avg_queue_size */ 1275static int bfqg_print_avg_queue_size(struct seq_file *sf, void *v) 1276{ 1277 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1278 bfqg_prfill_avg_queue_size, &blkcg_policy_bfq, 1279 0, false); 1280 return 0; 1281} 1282#endif /* CONFIG_BFQ_CGROUP_DEBUG */ 1283 1284struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node) 1285{ 1286 int ret; 1287 1288 ret = blkcg_activate_policy(bfqd->queue->disk, &blkcg_policy_bfq); 1289 if (ret) 1290 return NULL; 1291 1292 return blkg_to_bfqg(bfqd->queue->root_blkg); 1293} 1294 1295struct 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 1309struct 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 1435struct 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 1447void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, 1448 struct bfq_group *bfqg) {} 1449 1450void 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 1463void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) {} 1464 1465void bfq_end_wr_async(struct bfq_data *bfqd) 1466{ 1467 bfq_end_wr_async_queues(bfqd, bfqd->root_group); 1468} 1469 1470struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio) 1471{ 1472 return bfqd->root_group; 1473} 1474 1475struct bfq_group *bfqq_group(struct bfq_queue *bfqq) 1476{ 1477 return bfqq->bfqd->root_group; 1478} 1479 1480void bfqg_and_blkg_put(struct bfq_group *bfqg) {} 1481 1482struct 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