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/elevator.h> 10 #include <linux/ktime.h> 11 #include <linux/rbtree.h> 12 #include <linux/ioprio.h> 13 #include <linux/sbitmap.h> 14 #include <linux/delay.h> 15 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(&stat->aux_cnt, 0); 28 return 0; 29 } 30 31 static 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 */ 44 static 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 */ 53 static 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 */ 62 static 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 */ 75 static 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 */ 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, bfq_stat_read((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(&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. */ 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(&stats->empty_time, 162 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(&bfqg->stats.dequeue, 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(&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(&stats->idle_time, 199 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(&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 } 221 222 void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq, 223 unsigned int op) 224 { 225 blkg_rwstat_add(&bfqg->stats.queued, op, 1); 226 bfqg_stats_end_empty_time(&bfqg->stats); 227 if (!(bfqq == ((struct bfq_data *)bfqg->bfqd)->in_service_queue)) 228 bfqg_stats_set_start_group_wait_time(bfqg, bfqq_group(bfqq)); 229 } 230 231 void bfqg_stats_update_io_remove(struct bfq_group *bfqg, unsigned int op) 232 { 233 blkg_rwstat_add(&bfqg->stats.queued, op, -1); 234 } 235 236 void bfqg_stats_update_io_merged(struct bfq_group *bfqg, unsigned int op) 237 { 238 blkg_rwstat_add(&bfqg->stats.merged, op, 1); 239 } 240 241 void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns, 242 u64 io_start_time_ns, unsigned int op) 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(&stats->service_time, op, 249 now - io_start_time_ns); 250 if (io_start_time_ns > start_time_ns) 251 blkg_rwstat_add(&stats->wait_time, op, 252 io_start_time_ns - start_time_ns); 253 } 254 255 #else /* CONFIG_BFQ_CGROUP_DEBUG */ 256 257 void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq, 258 unsigned int op) { } 259 void bfqg_stats_update_io_remove(struct bfq_group *bfqg, unsigned int op) { } 260 void bfqg_stats_update_io_merged(struct bfq_group *bfqg, unsigned int op) { } 261 void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns, 262 u64 io_start_time_ns, unsigned int op) { } 263 void bfqg_stats_update_dequeue(struct bfq_group *bfqg) { } 264 void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg) { } 265 void bfqg_stats_update_idle_time(struct bfq_group *bfqg) { } 266 void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg) { } 267 void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg) { } 268 269 #endif /* CONFIG_BFQ_CGROUP_DEBUG */ 270 271 #ifdef CONFIG_BFQ_GROUP_IOSCHED 272 273 /* 274 * blk-cgroup policy-related handlers 275 * The following functions help in converting between blk-cgroup 276 * internal structures and BFQ-specific structures. 277 */ 278 279 static struct bfq_group *pd_to_bfqg(struct blkg_policy_data *pd) 280 { 281 return pd ? container_of(pd, struct bfq_group, pd) : NULL; 282 } 283 284 struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg) 285 { 286 return pd_to_blkg(&bfqg->pd); 287 } 288 289 static struct bfq_group *blkg_to_bfqg(struct blkcg_gq *blkg) 290 { 291 return pd_to_bfqg(blkg_to_pd(blkg, &blkcg_policy_bfq)); 292 } 293 294 /* 295 * bfq_group handlers 296 * The following functions help in navigating the bfq_group hierarchy 297 * by allowing to find the parent of a bfq_group or the bfq_group 298 * associated to a bfq_queue. 299 */ 300 301 static struct bfq_group *bfqg_parent(struct bfq_group *bfqg) 302 { 303 struct blkcg_gq *pblkg = bfqg_to_blkg(bfqg)->parent; 304 305 return pblkg ? blkg_to_bfqg(pblkg) : NULL; 306 } 307 308 struct bfq_group *bfqq_group(struct bfq_queue *bfqq) 309 { 310 struct bfq_entity *group_entity = bfqq->entity.parent; 311 312 return group_entity ? container_of(group_entity, struct bfq_group, 313 entity) : 314 bfqq->bfqd->root_group; 315 } 316 317 /* 318 * The following two functions handle get and put of a bfq_group by 319 * wrapping the related blk-cgroup hooks. 320 */ 321 322 static void bfqg_get(struct bfq_group *bfqg) 323 { 324 bfqg->ref++; 325 } 326 327 static void bfqg_put(struct bfq_group *bfqg) 328 { 329 bfqg->ref--; 330 331 if (bfqg->ref == 0) 332 kfree(bfqg); 333 } 334 335 static void bfqg_and_blkg_get(struct bfq_group *bfqg) 336 { 337 /* see comments in bfq_bic_update_cgroup for why refcounting bfqg */ 338 bfqg_get(bfqg); 339 340 blkg_get(bfqg_to_blkg(bfqg)); 341 } 342 343 void bfqg_and_blkg_put(struct bfq_group *bfqg) 344 { 345 blkg_put(bfqg_to_blkg(bfqg)); 346 347 bfqg_put(bfqg); 348 } 349 350 void bfqg_stats_update_legacy_io(struct request_queue *q, struct request *rq) 351 { 352 struct bfq_group *bfqg = blkg_to_bfqg(rq->bio->bi_blkg); 353 354 if (!bfqg) 355 return; 356 357 blkg_rwstat_add(&bfqg->stats.bytes, rq->cmd_flags, blk_rq_bytes(rq)); 358 blkg_rwstat_add(&bfqg->stats.ios, rq->cmd_flags, 1); 359 } 360 361 /* @stats = 0 */ 362 static void bfqg_stats_reset(struct bfqg_stats *stats) 363 { 364 #ifdef CONFIG_BFQ_CGROUP_DEBUG 365 /* queued stats shouldn't be cleared */ 366 blkg_rwstat_reset(&stats->merged); 367 blkg_rwstat_reset(&stats->service_time); 368 blkg_rwstat_reset(&stats->wait_time); 369 bfq_stat_reset(&stats->time); 370 bfq_stat_reset(&stats->avg_queue_size_sum); 371 bfq_stat_reset(&stats->avg_queue_size_samples); 372 bfq_stat_reset(&stats->dequeue); 373 bfq_stat_reset(&stats->group_wait_time); 374 bfq_stat_reset(&stats->idle_time); 375 bfq_stat_reset(&stats->empty_time); 376 #endif 377 } 378 379 /* @to += @from */ 380 static void bfqg_stats_add_aux(struct bfqg_stats *to, struct bfqg_stats *from) 381 { 382 if (!to || !from) 383 return; 384 385 #ifdef CONFIG_BFQ_CGROUP_DEBUG 386 /* queued stats shouldn't be cleared */ 387 blkg_rwstat_add_aux(&to->merged, &from->merged); 388 blkg_rwstat_add_aux(&to->service_time, &from->service_time); 389 blkg_rwstat_add_aux(&to->wait_time, &from->wait_time); 390 bfq_stat_add_aux(&from->time, &from->time); 391 bfq_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum); 392 bfq_stat_add_aux(&to->avg_queue_size_samples, 393 &from->avg_queue_size_samples); 394 bfq_stat_add_aux(&to->dequeue, &from->dequeue); 395 bfq_stat_add_aux(&to->group_wait_time, &from->group_wait_time); 396 bfq_stat_add_aux(&to->idle_time, &from->idle_time); 397 bfq_stat_add_aux(&to->empty_time, &from->empty_time); 398 #endif 399 } 400 401 /* 402 * Transfer @bfqg's stats to its parent's aux counts so that the ancestors' 403 * recursive stats can still account for the amount used by this bfqg after 404 * it's gone. 405 */ 406 static void bfqg_stats_xfer_dead(struct bfq_group *bfqg) 407 { 408 struct bfq_group *parent; 409 410 if (!bfqg) /* root_group */ 411 return; 412 413 parent = bfqg_parent(bfqg); 414 415 lockdep_assert_held(&bfqg_to_blkg(bfqg)->q->queue_lock); 416 417 if (unlikely(!parent)) 418 return; 419 420 bfqg_stats_add_aux(&parent->stats, &bfqg->stats); 421 bfqg_stats_reset(&bfqg->stats); 422 } 423 424 void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg) 425 { 426 struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); 427 428 entity->weight = entity->new_weight; 429 entity->orig_weight = entity->new_weight; 430 if (bfqq) { 431 bfqq->ioprio = bfqq->new_ioprio; 432 bfqq->ioprio_class = bfqq->new_ioprio_class; 433 /* 434 * Make sure that bfqg and its associated blkg do not 435 * disappear before entity. 436 */ 437 bfqg_and_blkg_get(bfqg); 438 } 439 entity->parent = bfqg->my_entity; /* NULL for root group */ 440 entity->sched_data = &bfqg->sched_data; 441 } 442 443 static void bfqg_stats_exit(struct bfqg_stats *stats) 444 { 445 blkg_rwstat_exit(&stats->bytes); 446 blkg_rwstat_exit(&stats->ios); 447 #ifdef CONFIG_BFQ_CGROUP_DEBUG 448 blkg_rwstat_exit(&stats->merged); 449 blkg_rwstat_exit(&stats->service_time); 450 blkg_rwstat_exit(&stats->wait_time); 451 blkg_rwstat_exit(&stats->queued); 452 bfq_stat_exit(&stats->time); 453 bfq_stat_exit(&stats->avg_queue_size_sum); 454 bfq_stat_exit(&stats->avg_queue_size_samples); 455 bfq_stat_exit(&stats->dequeue); 456 bfq_stat_exit(&stats->group_wait_time); 457 bfq_stat_exit(&stats->idle_time); 458 bfq_stat_exit(&stats->empty_time); 459 #endif 460 } 461 462 static int bfqg_stats_init(struct bfqg_stats *stats, gfp_t gfp) 463 { 464 if (blkg_rwstat_init(&stats->bytes, gfp) || 465 blkg_rwstat_init(&stats->ios, gfp)) 466 return -ENOMEM; 467 468 #ifdef CONFIG_BFQ_CGROUP_DEBUG 469 if (blkg_rwstat_init(&stats->merged, gfp) || 470 blkg_rwstat_init(&stats->service_time, gfp) || 471 blkg_rwstat_init(&stats->wait_time, gfp) || 472 blkg_rwstat_init(&stats->queued, gfp) || 473 bfq_stat_init(&stats->time, gfp) || 474 bfq_stat_init(&stats->avg_queue_size_sum, gfp) || 475 bfq_stat_init(&stats->avg_queue_size_samples, gfp) || 476 bfq_stat_init(&stats->dequeue, gfp) || 477 bfq_stat_init(&stats->group_wait_time, gfp) || 478 bfq_stat_init(&stats->idle_time, gfp) || 479 bfq_stat_init(&stats->empty_time, gfp)) { 480 bfqg_stats_exit(stats); 481 return -ENOMEM; 482 } 483 #endif 484 485 return 0; 486 } 487 488 static struct bfq_group_data *cpd_to_bfqgd(struct blkcg_policy_data *cpd) 489 { 490 return cpd ? container_of(cpd, struct bfq_group_data, pd) : NULL; 491 } 492 493 static struct bfq_group_data *blkcg_to_bfqgd(struct blkcg *blkcg) 494 { 495 return cpd_to_bfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_bfq)); 496 } 497 498 static struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp) 499 { 500 struct bfq_group_data *bgd; 501 502 bgd = kzalloc(sizeof(*bgd), gfp); 503 if (!bgd) 504 return NULL; 505 return &bgd->pd; 506 } 507 508 static void bfq_cpd_init(struct blkcg_policy_data *cpd) 509 { 510 struct bfq_group_data *d = cpd_to_bfqgd(cpd); 511 512 d->weight = cgroup_subsys_on_dfl(io_cgrp_subsys) ? 513 CGROUP_WEIGHT_DFL : BFQ_WEIGHT_LEGACY_DFL; 514 } 515 516 static void bfq_cpd_free(struct blkcg_policy_data *cpd) 517 { 518 kfree(cpd_to_bfqgd(cpd)); 519 } 520 521 static struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, struct request_queue *q, 522 struct blkcg *blkcg) 523 { 524 struct bfq_group *bfqg; 525 526 bfqg = kzalloc_node(sizeof(*bfqg), gfp, q->node); 527 if (!bfqg) 528 return NULL; 529 530 if (bfqg_stats_init(&bfqg->stats, gfp)) { 531 kfree(bfqg); 532 return NULL; 533 } 534 535 /* see comments in bfq_bic_update_cgroup for why refcounting */ 536 bfqg_get(bfqg); 537 return &bfqg->pd; 538 } 539 540 static void bfq_pd_init(struct blkg_policy_data *pd) 541 { 542 struct blkcg_gq *blkg = pd_to_blkg(pd); 543 struct bfq_group *bfqg = blkg_to_bfqg(blkg); 544 struct bfq_data *bfqd = blkg->q->elevator->elevator_data; 545 struct bfq_entity *entity = &bfqg->entity; 546 struct bfq_group_data *d = blkcg_to_bfqgd(blkg->blkcg); 547 548 entity->orig_weight = entity->weight = entity->new_weight = d->weight; 549 entity->my_sched_data = &bfqg->sched_data; 550 entity->last_bfqq_created = NULL; 551 552 bfqg->my_entity = entity; /* 553 * the root_group's will be set to NULL 554 * in bfq_init_queue() 555 */ 556 bfqg->bfqd = bfqd; 557 bfqg->active_entities = 0; 558 bfqg->rq_pos_tree = RB_ROOT; 559 } 560 561 static void bfq_pd_free(struct blkg_policy_data *pd) 562 { 563 struct bfq_group *bfqg = pd_to_bfqg(pd); 564 565 bfqg_stats_exit(&bfqg->stats); 566 bfqg_put(bfqg); 567 } 568 569 static void bfq_pd_reset_stats(struct blkg_policy_data *pd) 570 { 571 struct bfq_group *bfqg = pd_to_bfqg(pd); 572 573 bfqg_stats_reset(&bfqg->stats); 574 } 575 576 static void bfq_group_set_parent(struct bfq_group *bfqg, 577 struct bfq_group *parent) 578 { 579 struct bfq_entity *entity; 580 581 entity = &bfqg->entity; 582 entity->parent = parent->my_entity; 583 entity->sched_data = &parent->sched_data; 584 } 585 586 static struct bfq_group *bfq_lookup_bfqg(struct bfq_data *bfqd, 587 struct blkcg *blkcg) 588 { 589 struct blkcg_gq *blkg; 590 591 blkg = blkg_lookup(blkcg, bfqd->queue); 592 if (likely(blkg)) 593 return blkg_to_bfqg(blkg); 594 return NULL; 595 } 596 597 struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, 598 struct blkcg *blkcg) 599 { 600 struct bfq_group *bfqg, *parent; 601 struct bfq_entity *entity; 602 603 bfqg = bfq_lookup_bfqg(bfqd, blkcg); 604 605 if (unlikely(!bfqg)) 606 return NULL; 607 608 /* 609 * Update chain of bfq_groups as we might be handling a leaf group 610 * which, along with some of its relatives, has not been hooked yet 611 * to the private hierarchy of BFQ. 612 */ 613 entity = &bfqg->entity; 614 for_each_entity(entity) { 615 struct bfq_group *curr_bfqg = container_of(entity, 616 struct bfq_group, entity); 617 if (curr_bfqg != bfqd->root_group) { 618 parent = bfqg_parent(curr_bfqg); 619 if (!parent) 620 parent = bfqd->root_group; 621 bfq_group_set_parent(curr_bfqg, parent); 622 } 623 } 624 625 return bfqg; 626 } 627 628 /** 629 * bfq_bfqq_move - migrate @bfqq to @bfqg. 630 * @bfqd: queue descriptor. 631 * @bfqq: the queue to move. 632 * @bfqg: the group to move to. 633 * 634 * Move @bfqq to @bfqg, deactivating it from its old group and reactivating 635 * it on the new one. Avoid putting the entity on the old group idle tree. 636 * 637 * Must be called under the scheduler lock, to make sure that the blkg 638 * owning @bfqg does not disappear (see comments in 639 * bfq_bic_update_cgroup on guaranteeing the consistency of blkg 640 * objects). 641 */ 642 void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, 643 struct bfq_group *bfqg) 644 { 645 struct bfq_entity *entity = &bfqq->entity; 646 647 /* 648 * Get extra reference to prevent bfqq from being freed in 649 * next possible expire or deactivate. 650 */ 651 bfqq->ref++; 652 653 /* If bfqq is empty, then bfq_bfqq_expire also invokes 654 * bfq_del_bfqq_busy, thereby removing bfqq and its entity 655 * from data structures related to current group. Otherwise we 656 * need to remove bfqq explicitly with bfq_deactivate_bfqq, as 657 * we do below. 658 */ 659 if (bfqq == bfqd->in_service_queue) 660 bfq_bfqq_expire(bfqd, bfqd->in_service_queue, 661 false, BFQQE_PREEMPTED); 662 663 if (bfq_bfqq_busy(bfqq)) 664 bfq_deactivate_bfqq(bfqd, bfqq, false, false); 665 else if (entity->on_st_or_in_serv) 666 bfq_put_idle_entity(bfq_entity_service_tree(entity), entity); 667 bfqg_and_blkg_put(bfqq_group(bfqq)); 668 669 entity->parent = bfqg->my_entity; 670 entity->sched_data = &bfqg->sched_data; 671 /* pin down bfqg and its associated blkg */ 672 bfqg_and_blkg_get(bfqg); 673 674 if (bfq_bfqq_busy(bfqq)) { 675 if (unlikely(!bfqd->nonrot_with_queueing)) 676 bfq_pos_tree_add_move(bfqd, bfqq); 677 bfq_activate_bfqq(bfqd, bfqq); 678 } 679 680 if (!bfqd->in_service_queue && !bfqd->rq_in_driver) 681 bfq_schedule_dispatch(bfqd); 682 /* release extra ref taken above, bfqq may happen to be freed now */ 683 bfq_put_queue(bfqq); 684 } 685 686 /** 687 * __bfq_bic_change_cgroup - move @bic to @cgroup. 688 * @bfqd: the queue descriptor. 689 * @bic: the bic to move. 690 * @blkcg: the blk-cgroup to move to. 691 * 692 * Move bic to blkcg, assuming that bfqd->lock is held; which makes 693 * sure that the reference to cgroup is valid across the call (see 694 * comments in bfq_bic_update_cgroup on this issue) 695 * 696 * NOTE: an alternative approach might have been to store the current 697 * cgroup in bfqq and getting a reference to it, reducing the lookup 698 * time here, at the price of slightly more complex code. 699 */ 700 static struct bfq_group *__bfq_bic_change_cgroup(struct bfq_data *bfqd, 701 struct bfq_io_cq *bic, 702 struct blkcg *blkcg) 703 { 704 struct bfq_queue *async_bfqq = bic_to_bfqq(bic, 0); 705 struct bfq_queue *sync_bfqq = bic_to_bfqq(bic, 1); 706 struct bfq_group *bfqg; 707 struct bfq_entity *entity; 708 709 bfqg = bfq_find_set_group(bfqd, blkcg); 710 711 if (unlikely(!bfqg)) 712 bfqg = bfqd->root_group; 713 714 if (async_bfqq) { 715 entity = &async_bfqq->entity; 716 717 if (entity->sched_data != &bfqg->sched_data) { 718 bic_set_bfqq(bic, NULL, 0); 719 bfq_release_process_ref(bfqd, async_bfqq); 720 } 721 } 722 723 if (sync_bfqq) { 724 entity = &sync_bfqq->entity; 725 if (entity->sched_data != &bfqg->sched_data) 726 bfq_bfqq_move(bfqd, sync_bfqq, bfqg); 727 } 728 729 return bfqg; 730 } 731 732 void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) 733 { 734 struct bfq_data *bfqd = bic_to_bfqd(bic); 735 struct bfq_group *bfqg = NULL; 736 uint64_t serial_nr; 737 738 rcu_read_lock(); 739 serial_nr = __bio_blkcg(bio)->css.serial_nr; 740 741 /* 742 * Check whether blkcg has changed. The condition may trigger 743 * spuriously on a newly created cic but there's no harm. 744 */ 745 if (unlikely(!bfqd) || likely(bic->blkcg_serial_nr == serial_nr)) 746 goto out; 747 748 bfqg = __bfq_bic_change_cgroup(bfqd, bic, __bio_blkcg(bio)); 749 /* 750 * Update blkg_path for bfq_log_* functions. We cache this 751 * path, and update it here, for the following 752 * reasons. Operations on blkg objects in blk-cgroup are 753 * protected with the request_queue lock, and not with the 754 * lock that protects the instances of this scheduler 755 * (bfqd->lock). This exposes BFQ to the following sort of 756 * race. 757 * 758 * The blkg_lookup performed in bfq_get_queue, protected 759 * through rcu, may happen to return the address of a copy of 760 * the original blkg. If this is the case, then the 761 * bfqg_and_blkg_get performed in bfq_get_queue, to pin down 762 * the blkg, is useless: it does not prevent blk-cgroup code 763 * from destroying both the original blkg and all objects 764 * directly or indirectly referred by the copy of the 765 * blkg. 766 * 767 * On the bright side, destroy operations on a blkg invoke, as 768 * a first step, hooks of the scheduler associated with the 769 * blkg. And these hooks are executed with bfqd->lock held for 770 * BFQ. As a consequence, for any blkg associated with the 771 * request queue this instance of the scheduler is attached 772 * to, we are guaranteed that such a blkg is not destroyed, and 773 * that all the pointers it contains are consistent, while we 774 * are holding bfqd->lock. A blkg_lookup performed with 775 * bfqd->lock held then returns a fully consistent blkg, which 776 * remains consistent until this lock is held. 777 * 778 * Thanks to the last fact, and to the fact that: (1) bfqg has 779 * been obtained through a blkg_lookup in the above 780 * assignment, and (2) bfqd->lock is being held, here we can 781 * safely use the policy data for the involved blkg (i.e., the 782 * field bfqg->pd) to get to the blkg associated with bfqg, 783 * and then we can safely use any field of blkg. After we 784 * release bfqd->lock, even just getting blkg through this 785 * bfqg may cause dangling references to be traversed, as 786 * bfqg->pd may not exist any more. 787 * 788 * In view of the above facts, here we cache, in the bfqg, any 789 * blkg data we may need for this bic, and for its associated 790 * bfq_queue. As of now, we need to cache only the path of the 791 * blkg, which is used in the bfq_log_* functions. 792 * 793 * Finally, note that bfqg itself needs to be protected from 794 * destruction on the blkg_free of the original blkg (which 795 * invokes bfq_pd_free). We use an additional private 796 * refcounter for bfqg, to let it disappear only after no 797 * bfq_queue refers to it any longer. 798 */ 799 blkg_path(bfqg_to_blkg(bfqg), bfqg->blkg_path, sizeof(bfqg->blkg_path)); 800 bic->blkcg_serial_nr = serial_nr; 801 out: 802 rcu_read_unlock(); 803 } 804 805 /** 806 * bfq_flush_idle_tree - deactivate any entity on the idle tree of @st. 807 * @st: the service tree being flushed. 808 */ 809 static void bfq_flush_idle_tree(struct bfq_service_tree *st) 810 { 811 struct bfq_entity *entity = st->first_idle; 812 813 for (; entity ; entity = st->first_idle) 814 __bfq_deactivate_entity(entity, false); 815 } 816 817 /** 818 * bfq_reparent_leaf_entity - move leaf entity to the root_group. 819 * @bfqd: the device data structure with the root group. 820 * @entity: the entity to move, if entity is a leaf; or the parent entity 821 * of an active leaf entity to move, if entity is not a leaf. 822 */ 823 static void bfq_reparent_leaf_entity(struct bfq_data *bfqd, 824 struct bfq_entity *entity, 825 int ioprio_class) 826 { 827 struct bfq_queue *bfqq; 828 struct bfq_entity *child_entity = entity; 829 830 while (child_entity->my_sched_data) { /* leaf not reached yet */ 831 struct bfq_sched_data *child_sd = child_entity->my_sched_data; 832 struct bfq_service_tree *child_st = child_sd->service_tree + 833 ioprio_class; 834 struct rb_root *child_active = &child_st->active; 835 836 child_entity = bfq_entity_of(rb_first(child_active)); 837 838 if (!child_entity) 839 child_entity = child_sd->in_service_entity; 840 } 841 842 bfqq = bfq_entity_to_bfqq(child_entity); 843 bfq_bfqq_move(bfqd, bfqq, bfqd->root_group); 844 } 845 846 /** 847 * bfq_reparent_active_queues - move to the root group all active queues. 848 * @bfqd: the device data structure with the root group. 849 * @bfqg: the group to move from. 850 * @st: the service tree to start the search from. 851 */ 852 static void bfq_reparent_active_queues(struct bfq_data *bfqd, 853 struct bfq_group *bfqg, 854 struct bfq_service_tree *st, 855 int ioprio_class) 856 { 857 struct rb_root *active = &st->active; 858 struct bfq_entity *entity; 859 860 while ((entity = bfq_entity_of(rb_first(active)))) 861 bfq_reparent_leaf_entity(bfqd, entity, ioprio_class); 862 863 if (bfqg->sched_data.in_service_entity) 864 bfq_reparent_leaf_entity(bfqd, 865 bfqg->sched_data.in_service_entity, 866 ioprio_class); 867 } 868 869 /** 870 * bfq_pd_offline - deactivate the entity associated with @pd, 871 * and reparent its children entities. 872 * @pd: descriptor of the policy going offline. 873 * 874 * blkio already grabs the queue_lock for us, so no need to use 875 * RCU-based magic 876 */ 877 static void bfq_pd_offline(struct blkg_policy_data *pd) 878 { 879 struct bfq_service_tree *st; 880 struct bfq_group *bfqg = pd_to_bfqg(pd); 881 struct bfq_data *bfqd = bfqg->bfqd; 882 struct bfq_entity *entity = bfqg->my_entity; 883 unsigned long flags; 884 int i; 885 886 spin_lock_irqsave(&bfqd->lock, flags); 887 888 if (!entity) /* root group */ 889 goto put_async_queues; 890 891 /* 892 * Empty all service_trees belonging to this group before 893 * deactivating the group itself. 894 */ 895 for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) { 896 st = bfqg->sched_data.service_tree + i; 897 898 /* 899 * It may happen that some queues are still active 900 * (busy) upon group destruction (if the corresponding 901 * processes have been forced to terminate). We move 902 * all the leaf entities corresponding to these queues 903 * to the root_group. 904 * Also, it may happen that the group has an entity 905 * in service, which is disconnected from the active 906 * tree: it must be moved, too. 907 * There is no need to put the sync queues, as the 908 * scheduler has taken no reference. 909 */ 910 bfq_reparent_active_queues(bfqd, bfqg, st, i); 911 912 /* 913 * The idle tree may still contain bfq_queues 914 * belonging to exited task because they never 915 * migrated to a different cgroup from the one being 916 * destroyed now. In addition, even 917 * bfq_reparent_active_queues() may happen to add some 918 * entities to the idle tree. It happens if, in some 919 * of the calls to bfq_bfqq_move() performed by 920 * bfq_reparent_active_queues(), the queue to move is 921 * empty and gets expired. 922 */ 923 bfq_flush_idle_tree(st); 924 } 925 926 __bfq_deactivate_entity(entity, false); 927 928 put_async_queues: 929 bfq_put_async_queues(bfqd, bfqg); 930 931 spin_unlock_irqrestore(&bfqd->lock, flags); 932 /* 933 * @blkg is going offline and will be ignored by 934 * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so 935 * that they don't get lost. If IOs complete after this point, the 936 * stats for them will be lost. Oh well... 937 */ 938 bfqg_stats_xfer_dead(bfqg); 939 } 940 941 void bfq_end_wr_async(struct bfq_data *bfqd) 942 { 943 struct blkcg_gq *blkg; 944 945 list_for_each_entry(blkg, &bfqd->queue->blkg_list, q_node) { 946 struct bfq_group *bfqg = blkg_to_bfqg(blkg); 947 948 bfq_end_wr_async_queues(bfqd, bfqg); 949 } 950 bfq_end_wr_async_queues(bfqd, bfqd->root_group); 951 } 952 953 static int bfq_io_show_weight_legacy(struct seq_file *sf, void *v) 954 { 955 struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); 956 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); 957 unsigned int val = 0; 958 959 if (bfqgd) 960 val = bfqgd->weight; 961 962 seq_printf(sf, "%u\n", val); 963 964 return 0; 965 } 966 967 static u64 bfqg_prfill_weight_device(struct seq_file *sf, 968 struct blkg_policy_data *pd, int off) 969 { 970 struct bfq_group *bfqg = pd_to_bfqg(pd); 971 972 if (!bfqg->entity.dev_weight) 973 return 0; 974 return __blkg_prfill_u64(sf, pd, bfqg->entity.dev_weight); 975 } 976 977 static int bfq_io_show_weight(struct seq_file *sf, void *v) 978 { 979 struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); 980 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); 981 982 seq_printf(sf, "default %u\n", bfqgd->weight); 983 blkcg_print_blkgs(sf, blkcg, bfqg_prfill_weight_device, 984 &blkcg_policy_bfq, 0, false); 985 return 0; 986 } 987 988 static void bfq_group_set_weight(struct bfq_group *bfqg, u64 weight, u64 dev_weight) 989 { 990 weight = dev_weight ?: weight; 991 992 bfqg->entity.dev_weight = dev_weight; 993 /* 994 * Setting the prio_changed flag of the entity 995 * to 1 with new_weight == weight would re-set 996 * the value of the weight to its ioprio mapping. 997 * Set the flag only if necessary. 998 */ 999 if ((unsigned short)weight != bfqg->entity.new_weight) { 1000 bfqg->entity.new_weight = (unsigned short)weight; 1001 /* 1002 * Make sure that the above new value has been 1003 * stored in bfqg->entity.new_weight before 1004 * setting the prio_changed flag. In fact, 1005 * this flag may be read asynchronously (in 1006 * critical sections protected by a different 1007 * lock than that held here), and finding this 1008 * flag set may cause the execution of the code 1009 * for updating parameters whose value may 1010 * depend also on bfqg->entity.new_weight (in 1011 * __bfq_entity_update_weight_prio). 1012 * This barrier makes sure that the new value 1013 * of bfqg->entity.new_weight is correctly 1014 * seen in that code. 1015 */ 1016 smp_wmb(); 1017 bfqg->entity.prio_changed = 1; 1018 } 1019 } 1020 1021 static int bfq_io_set_weight_legacy(struct cgroup_subsys_state *css, 1022 struct cftype *cftype, 1023 u64 val) 1024 { 1025 struct blkcg *blkcg = css_to_blkcg(css); 1026 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); 1027 struct blkcg_gq *blkg; 1028 int ret = -ERANGE; 1029 1030 if (val < BFQ_MIN_WEIGHT || val > BFQ_MAX_WEIGHT) 1031 return ret; 1032 1033 ret = 0; 1034 spin_lock_irq(&blkcg->lock); 1035 bfqgd->weight = (unsigned short)val; 1036 hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { 1037 struct bfq_group *bfqg = blkg_to_bfqg(blkg); 1038 1039 if (bfqg) 1040 bfq_group_set_weight(bfqg, val, 0); 1041 } 1042 spin_unlock_irq(&blkcg->lock); 1043 1044 return ret; 1045 } 1046 1047 static ssize_t bfq_io_set_device_weight(struct kernfs_open_file *of, 1048 char *buf, size_t nbytes, 1049 loff_t off) 1050 { 1051 int ret; 1052 struct blkg_conf_ctx ctx; 1053 struct blkcg *blkcg = css_to_blkcg(of_css(of)); 1054 struct bfq_group *bfqg; 1055 u64 v; 1056 1057 ret = blkg_conf_prep(blkcg, &blkcg_policy_bfq, buf, &ctx); 1058 if (ret) 1059 return ret; 1060 1061 if (sscanf(ctx.body, "%llu", &v) == 1) { 1062 /* require "default" on dfl */ 1063 ret = -ERANGE; 1064 if (!v) 1065 goto out; 1066 } else if (!strcmp(strim(ctx.body), "default")) { 1067 v = 0; 1068 } else { 1069 ret = -EINVAL; 1070 goto out; 1071 } 1072 1073 bfqg = blkg_to_bfqg(ctx.blkg); 1074 1075 ret = -ERANGE; 1076 if (!v || (v >= BFQ_MIN_WEIGHT && v <= BFQ_MAX_WEIGHT)) { 1077 bfq_group_set_weight(bfqg, bfqg->entity.weight, v); 1078 ret = 0; 1079 } 1080 out: 1081 blkg_conf_finish(&ctx); 1082 return ret ?: nbytes; 1083 } 1084 1085 static ssize_t bfq_io_set_weight(struct kernfs_open_file *of, 1086 char *buf, size_t nbytes, 1087 loff_t off) 1088 { 1089 char *endp; 1090 int ret; 1091 u64 v; 1092 1093 buf = strim(buf); 1094 1095 /* "WEIGHT" or "default WEIGHT" sets the default weight */ 1096 v = simple_strtoull(buf, &endp, 0); 1097 if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) { 1098 ret = bfq_io_set_weight_legacy(of_css(of), NULL, v); 1099 return ret ?: nbytes; 1100 } 1101 1102 return bfq_io_set_device_weight(of, buf, nbytes, off); 1103 } 1104 1105 static int bfqg_print_rwstat(struct seq_file *sf, void *v) 1106 { 1107 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat, 1108 &blkcg_policy_bfq, seq_cft(sf)->private, true); 1109 return 0; 1110 } 1111 1112 static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf, 1113 struct blkg_policy_data *pd, int off) 1114 { 1115 struct blkg_rwstat_sample sum; 1116 1117 blkg_rwstat_recursive_sum(pd_to_blkg(pd), &blkcg_policy_bfq, off, &sum); 1118 return __blkg_prfill_rwstat(sf, pd, &sum); 1119 } 1120 1121 static int bfqg_print_rwstat_recursive(struct seq_file *sf, void *v) 1122 { 1123 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1124 bfqg_prfill_rwstat_recursive, &blkcg_policy_bfq, 1125 seq_cft(sf)->private, true); 1126 return 0; 1127 } 1128 1129 #ifdef CONFIG_BFQ_CGROUP_DEBUG 1130 static int bfqg_print_stat(struct seq_file *sf, void *v) 1131 { 1132 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat, 1133 &blkcg_policy_bfq, seq_cft(sf)->private, false); 1134 return 0; 1135 } 1136 1137 static u64 bfqg_prfill_stat_recursive(struct seq_file *sf, 1138 struct blkg_policy_data *pd, int off) 1139 { 1140 struct blkcg_gq *blkg = pd_to_blkg(pd); 1141 struct blkcg_gq *pos_blkg; 1142 struct cgroup_subsys_state *pos_css; 1143 u64 sum = 0; 1144 1145 lockdep_assert_held(&blkg->q->queue_lock); 1146 1147 rcu_read_lock(); 1148 blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { 1149 struct bfq_stat *stat; 1150 1151 if (!pos_blkg->online) 1152 continue; 1153 1154 stat = (void *)blkg_to_pd(pos_blkg, &blkcg_policy_bfq) + off; 1155 sum += bfq_stat_read(stat) + atomic64_read(&stat->aux_cnt); 1156 } 1157 rcu_read_unlock(); 1158 1159 return __blkg_prfill_u64(sf, pd, sum); 1160 } 1161 1162 static int bfqg_print_stat_recursive(struct seq_file *sf, void *v) 1163 { 1164 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1165 bfqg_prfill_stat_recursive, &blkcg_policy_bfq, 1166 seq_cft(sf)->private, false); 1167 return 0; 1168 } 1169 1170 static u64 bfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd, 1171 int off) 1172 { 1173 struct bfq_group *bfqg = blkg_to_bfqg(pd->blkg); 1174 u64 sum = blkg_rwstat_total(&bfqg->stats.bytes); 1175 1176 return __blkg_prfill_u64(sf, pd, sum >> 9); 1177 } 1178 1179 static int bfqg_print_stat_sectors(struct seq_file *sf, void *v) 1180 { 1181 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1182 bfqg_prfill_sectors, &blkcg_policy_bfq, 0, false); 1183 return 0; 1184 } 1185 1186 static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf, 1187 struct blkg_policy_data *pd, int off) 1188 { 1189 struct blkg_rwstat_sample tmp; 1190 1191 blkg_rwstat_recursive_sum(pd->blkg, &blkcg_policy_bfq, 1192 offsetof(struct bfq_group, stats.bytes), &tmp); 1193 1194 return __blkg_prfill_u64(sf, pd, 1195 (tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]) >> 9); 1196 } 1197 1198 static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v) 1199 { 1200 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1201 bfqg_prfill_sectors_recursive, &blkcg_policy_bfq, 0, 1202 false); 1203 return 0; 1204 } 1205 1206 static u64 bfqg_prfill_avg_queue_size(struct seq_file *sf, 1207 struct blkg_policy_data *pd, int off) 1208 { 1209 struct bfq_group *bfqg = pd_to_bfqg(pd); 1210 u64 samples = bfq_stat_read(&bfqg->stats.avg_queue_size_samples); 1211 u64 v = 0; 1212 1213 if (samples) { 1214 v = bfq_stat_read(&bfqg->stats.avg_queue_size_sum); 1215 v = div64_u64(v, samples); 1216 } 1217 __blkg_prfill_u64(sf, pd, v); 1218 return 0; 1219 } 1220 1221 /* print avg_queue_size */ 1222 static int bfqg_print_avg_queue_size(struct seq_file *sf, void *v) 1223 { 1224 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1225 bfqg_prfill_avg_queue_size, &blkcg_policy_bfq, 1226 0, false); 1227 return 0; 1228 } 1229 #endif /* CONFIG_BFQ_CGROUP_DEBUG */ 1230 1231 struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node) 1232 { 1233 int ret; 1234 1235 ret = blkcg_activate_policy(bfqd->queue, &blkcg_policy_bfq); 1236 if (ret) 1237 return NULL; 1238 1239 return blkg_to_bfqg(bfqd->queue->root_blkg); 1240 } 1241 1242 struct blkcg_policy blkcg_policy_bfq = { 1243 .dfl_cftypes = bfq_blkg_files, 1244 .legacy_cftypes = bfq_blkcg_legacy_files, 1245 1246 .cpd_alloc_fn = bfq_cpd_alloc, 1247 .cpd_init_fn = bfq_cpd_init, 1248 .cpd_bind_fn = bfq_cpd_init, 1249 .cpd_free_fn = bfq_cpd_free, 1250 1251 .pd_alloc_fn = bfq_pd_alloc, 1252 .pd_init_fn = bfq_pd_init, 1253 .pd_offline_fn = bfq_pd_offline, 1254 .pd_free_fn = bfq_pd_free, 1255 .pd_reset_stats_fn = bfq_pd_reset_stats, 1256 }; 1257 1258 struct cftype bfq_blkcg_legacy_files[] = { 1259 { 1260 .name = "bfq.weight", 1261 .flags = CFTYPE_NOT_ON_ROOT, 1262 .seq_show = bfq_io_show_weight_legacy, 1263 .write_u64 = bfq_io_set_weight_legacy, 1264 }, 1265 { 1266 .name = "bfq.weight_device", 1267 .flags = CFTYPE_NOT_ON_ROOT, 1268 .seq_show = bfq_io_show_weight, 1269 .write = bfq_io_set_weight, 1270 }, 1271 1272 /* statistics, covers only the tasks in the bfqg */ 1273 { 1274 .name = "bfq.io_service_bytes", 1275 .private = offsetof(struct bfq_group, stats.bytes), 1276 .seq_show = bfqg_print_rwstat, 1277 }, 1278 { 1279 .name = "bfq.io_serviced", 1280 .private = offsetof(struct bfq_group, stats.ios), 1281 .seq_show = bfqg_print_rwstat, 1282 }, 1283 #ifdef CONFIG_BFQ_CGROUP_DEBUG 1284 { 1285 .name = "bfq.time", 1286 .private = offsetof(struct bfq_group, stats.time), 1287 .seq_show = bfqg_print_stat, 1288 }, 1289 { 1290 .name = "bfq.sectors", 1291 .seq_show = bfqg_print_stat_sectors, 1292 }, 1293 { 1294 .name = "bfq.io_service_time", 1295 .private = offsetof(struct bfq_group, stats.service_time), 1296 .seq_show = bfqg_print_rwstat, 1297 }, 1298 { 1299 .name = "bfq.io_wait_time", 1300 .private = offsetof(struct bfq_group, stats.wait_time), 1301 .seq_show = bfqg_print_rwstat, 1302 }, 1303 { 1304 .name = "bfq.io_merged", 1305 .private = offsetof(struct bfq_group, stats.merged), 1306 .seq_show = bfqg_print_rwstat, 1307 }, 1308 { 1309 .name = "bfq.io_queued", 1310 .private = offsetof(struct bfq_group, stats.queued), 1311 .seq_show = bfqg_print_rwstat, 1312 }, 1313 #endif /* CONFIG_BFQ_CGROUP_DEBUG */ 1314 1315 /* the same statistics which cover the bfqg and its descendants */ 1316 { 1317 .name = "bfq.io_service_bytes_recursive", 1318 .private = offsetof(struct bfq_group, stats.bytes), 1319 .seq_show = bfqg_print_rwstat_recursive, 1320 }, 1321 { 1322 .name = "bfq.io_serviced_recursive", 1323 .private = offsetof(struct bfq_group, stats.ios), 1324 .seq_show = bfqg_print_rwstat_recursive, 1325 }, 1326 #ifdef CONFIG_BFQ_CGROUP_DEBUG 1327 { 1328 .name = "bfq.time_recursive", 1329 .private = offsetof(struct bfq_group, stats.time), 1330 .seq_show = bfqg_print_stat_recursive, 1331 }, 1332 { 1333 .name = "bfq.sectors_recursive", 1334 .seq_show = bfqg_print_stat_sectors_recursive, 1335 }, 1336 { 1337 .name = "bfq.io_service_time_recursive", 1338 .private = offsetof(struct bfq_group, stats.service_time), 1339 .seq_show = bfqg_print_rwstat_recursive, 1340 }, 1341 { 1342 .name = "bfq.io_wait_time_recursive", 1343 .private = offsetof(struct bfq_group, stats.wait_time), 1344 .seq_show = bfqg_print_rwstat_recursive, 1345 }, 1346 { 1347 .name = "bfq.io_merged_recursive", 1348 .private = offsetof(struct bfq_group, stats.merged), 1349 .seq_show = bfqg_print_rwstat_recursive, 1350 }, 1351 { 1352 .name = "bfq.io_queued_recursive", 1353 .private = offsetof(struct bfq_group, stats.queued), 1354 .seq_show = bfqg_print_rwstat_recursive, 1355 }, 1356 { 1357 .name = "bfq.avg_queue_size", 1358 .seq_show = bfqg_print_avg_queue_size, 1359 }, 1360 { 1361 .name = "bfq.group_wait_time", 1362 .private = offsetof(struct bfq_group, stats.group_wait_time), 1363 .seq_show = bfqg_print_stat, 1364 }, 1365 { 1366 .name = "bfq.idle_time", 1367 .private = offsetof(struct bfq_group, stats.idle_time), 1368 .seq_show = bfqg_print_stat, 1369 }, 1370 { 1371 .name = "bfq.empty_time", 1372 .private = offsetof(struct bfq_group, stats.empty_time), 1373 .seq_show = bfqg_print_stat, 1374 }, 1375 { 1376 .name = "bfq.dequeue", 1377 .private = offsetof(struct bfq_group, stats.dequeue), 1378 .seq_show = bfqg_print_stat, 1379 }, 1380 #endif /* CONFIG_BFQ_CGROUP_DEBUG */ 1381 { } /* terminate */ 1382 }; 1383 1384 struct cftype bfq_blkg_files[] = { 1385 { 1386 .name = "bfq.weight", 1387 .flags = CFTYPE_NOT_ON_ROOT, 1388 .seq_show = bfq_io_show_weight, 1389 .write = bfq_io_set_weight, 1390 }, 1391 {} /* terminate */ 1392 }; 1393 1394 #else /* CONFIG_BFQ_GROUP_IOSCHED */ 1395 1396 void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, 1397 struct bfq_group *bfqg) {} 1398 1399 void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg) 1400 { 1401 struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); 1402 1403 entity->weight = entity->new_weight; 1404 entity->orig_weight = entity->new_weight; 1405 if (bfqq) { 1406 bfqq->ioprio = bfqq->new_ioprio; 1407 bfqq->ioprio_class = bfqq->new_ioprio_class; 1408 } 1409 entity->sched_data = &bfqg->sched_data; 1410 } 1411 1412 void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) {} 1413 1414 void bfq_end_wr_async(struct bfq_data *bfqd) 1415 { 1416 bfq_end_wr_async_queues(bfqd, bfqd->root_group); 1417 } 1418 1419 struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, struct blkcg *blkcg) 1420 { 1421 return bfqd->root_group; 1422 } 1423 1424 struct bfq_group *bfqq_group(struct bfq_queue *bfqq) 1425 { 1426 return bfqq->bfqd->root_group; 1427 } 1428 1429 void bfqg_and_blkg_get(struct bfq_group *bfqg) {} 1430 1431 void bfqg_and_blkg_put(struct bfq_group *bfqg) {} 1432 1433 struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node) 1434 { 1435 struct bfq_group *bfqg; 1436 int i; 1437 1438 bfqg = kmalloc_node(sizeof(*bfqg), GFP_KERNEL | __GFP_ZERO, node); 1439 if (!bfqg) 1440 return NULL; 1441 1442 for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) 1443 bfqg->sched_data.service_tree[i] = BFQ_SERVICE_TREE_INIT; 1444 1445 return bfqg; 1446 } 1447 #endif /* CONFIG_BFQ_GROUP_IOSCHED */ 1448