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 bfqg->my_entity = entity; /* 551 * the root_group's will be set to NULL 552 * in bfq_init_queue() 553 */ 554 bfqg->bfqd = bfqd; 555 bfqg->active_entities = 0; 556 bfqg->rq_pos_tree = RB_ROOT; 557 } 558 559 static void bfq_pd_free(struct blkg_policy_data *pd) 560 { 561 struct bfq_group *bfqg = pd_to_bfqg(pd); 562 563 bfqg_stats_exit(&bfqg->stats); 564 bfqg_put(bfqg); 565 } 566 567 static void bfq_pd_reset_stats(struct blkg_policy_data *pd) 568 { 569 struct bfq_group *bfqg = pd_to_bfqg(pd); 570 571 bfqg_stats_reset(&bfqg->stats); 572 } 573 574 static void bfq_group_set_parent(struct bfq_group *bfqg, 575 struct bfq_group *parent) 576 { 577 struct bfq_entity *entity; 578 579 entity = &bfqg->entity; 580 entity->parent = parent->my_entity; 581 entity->sched_data = &parent->sched_data; 582 } 583 584 static struct bfq_group *bfq_lookup_bfqg(struct bfq_data *bfqd, 585 struct blkcg *blkcg) 586 { 587 struct blkcg_gq *blkg; 588 589 blkg = blkg_lookup(blkcg, bfqd->queue); 590 if (likely(blkg)) 591 return blkg_to_bfqg(blkg); 592 return NULL; 593 } 594 595 struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, 596 struct blkcg *blkcg) 597 { 598 struct bfq_group *bfqg, *parent; 599 struct bfq_entity *entity; 600 601 bfqg = bfq_lookup_bfqg(bfqd, blkcg); 602 603 if (unlikely(!bfqg)) 604 return NULL; 605 606 /* 607 * Update chain of bfq_groups as we might be handling a leaf group 608 * which, along with some of its relatives, has not been hooked yet 609 * to the private hierarchy of BFQ. 610 */ 611 entity = &bfqg->entity; 612 for_each_entity(entity) { 613 struct bfq_group *curr_bfqg = container_of(entity, 614 struct bfq_group, entity); 615 if (curr_bfqg != bfqd->root_group) { 616 parent = bfqg_parent(curr_bfqg); 617 if (!parent) 618 parent = bfqd->root_group; 619 bfq_group_set_parent(curr_bfqg, parent); 620 } 621 } 622 623 return bfqg; 624 } 625 626 /** 627 * bfq_bfqq_move - migrate @bfqq to @bfqg. 628 * @bfqd: queue descriptor. 629 * @bfqq: the queue to move. 630 * @bfqg: the group to move to. 631 * 632 * Move @bfqq to @bfqg, deactivating it from its old group and reactivating 633 * it on the new one. Avoid putting the entity on the old group idle tree. 634 * 635 * Must be called under the scheduler lock, to make sure that the blkg 636 * owning @bfqg does not disappear (see comments in 637 * bfq_bic_update_cgroup on guaranteeing the consistency of blkg 638 * objects). 639 */ 640 void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, 641 struct bfq_group *bfqg) 642 { 643 struct bfq_entity *entity = &bfqq->entity; 644 645 /* 646 * Get extra reference to prevent bfqq from being freed in 647 * next possible expire or deactivate. 648 */ 649 bfqq->ref++; 650 651 /* If bfqq is empty, then bfq_bfqq_expire also invokes 652 * bfq_del_bfqq_busy, thereby removing bfqq and its entity 653 * from data structures related to current group. Otherwise we 654 * need to remove bfqq explicitly with bfq_deactivate_bfqq, as 655 * we do below. 656 */ 657 if (bfqq == bfqd->in_service_queue) 658 bfq_bfqq_expire(bfqd, bfqd->in_service_queue, 659 false, BFQQE_PREEMPTED); 660 661 if (bfq_bfqq_busy(bfqq)) 662 bfq_deactivate_bfqq(bfqd, bfqq, false, false); 663 else if (entity->on_st_or_in_serv) 664 bfq_put_idle_entity(bfq_entity_service_tree(entity), entity); 665 bfqg_and_blkg_put(bfqq_group(bfqq)); 666 667 entity->parent = bfqg->my_entity; 668 entity->sched_data = &bfqg->sched_data; 669 /* pin down bfqg and its associated blkg */ 670 bfqg_and_blkg_get(bfqg); 671 672 if (bfq_bfqq_busy(bfqq)) { 673 if (unlikely(!bfqd->nonrot_with_queueing)) 674 bfq_pos_tree_add_move(bfqd, bfqq); 675 bfq_activate_bfqq(bfqd, bfqq); 676 } 677 678 if (!bfqd->in_service_queue && !bfqd->rq_in_driver) 679 bfq_schedule_dispatch(bfqd); 680 /* release extra ref taken above, bfqq may happen to be freed now */ 681 bfq_put_queue(bfqq); 682 } 683 684 /** 685 * __bfq_bic_change_cgroup - move @bic to @cgroup. 686 * @bfqd: the queue descriptor. 687 * @bic: the bic to move. 688 * @blkcg: the blk-cgroup to move to. 689 * 690 * Move bic to blkcg, assuming that bfqd->lock is held; which makes 691 * sure that the reference to cgroup is valid across the call (see 692 * comments in bfq_bic_update_cgroup on this issue) 693 * 694 * NOTE: an alternative approach might have been to store the current 695 * cgroup in bfqq and getting a reference to it, reducing the lookup 696 * time here, at the price of slightly more complex code. 697 */ 698 static struct bfq_group *__bfq_bic_change_cgroup(struct bfq_data *bfqd, 699 struct bfq_io_cq *bic, 700 struct blkcg *blkcg) 701 { 702 struct bfq_queue *async_bfqq = bic_to_bfqq(bic, 0); 703 struct bfq_queue *sync_bfqq = bic_to_bfqq(bic, 1); 704 struct bfq_group *bfqg; 705 struct bfq_entity *entity; 706 707 bfqg = bfq_find_set_group(bfqd, blkcg); 708 709 if (unlikely(!bfqg)) 710 bfqg = bfqd->root_group; 711 712 if (async_bfqq) { 713 entity = &async_bfqq->entity; 714 715 if (entity->sched_data != &bfqg->sched_data) { 716 bic_set_bfqq(bic, NULL, 0); 717 bfq_release_process_ref(bfqd, async_bfqq); 718 } 719 } 720 721 if (sync_bfqq) { 722 entity = &sync_bfqq->entity; 723 if (entity->sched_data != &bfqg->sched_data) 724 bfq_bfqq_move(bfqd, sync_bfqq, bfqg); 725 } 726 727 return bfqg; 728 } 729 730 void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) 731 { 732 struct bfq_data *bfqd = bic_to_bfqd(bic); 733 struct bfq_group *bfqg = NULL; 734 uint64_t serial_nr; 735 736 rcu_read_lock(); 737 serial_nr = __bio_blkcg(bio)->css.serial_nr; 738 739 /* 740 * Check whether blkcg has changed. The condition may trigger 741 * spuriously on a newly created cic but there's no harm. 742 */ 743 if (unlikely(!bfqd) || likely(bic->blkcg_serial_nr == serial_nr)) 744 goto out; 745 746 bfqg = __bfq_bic_change_cgroup(bfqd, bic, __bio_blkcg(bio)); 747 /* 748 * Update blkg_path for bfq_log_* functions. We cache this 749 * path, and update it here, for the following 750 * reasons. Operations on blkg objects in blk-cgroup are 751 * protected with the request_queue lock, and not with the 752 * lock that protects the instances of this scheduler 753 * (bfqd->lock). This exposes BFQ to the following sort of 754 * race. 755 * 756 * The blkg_lookup performed in bfq_get_queue, protected 757 * through rcu, may happen to return the address of a copy of 758 * the original blkg. If this is the case, then the 759 * bfqg_and_blkg_get performed in bfq_get_queue, to pin down 760 * the blkg, is useless: it does not prevent blk-cgroup code 761 * from destroying both the original blkg and all objects 762 * directly or indirectly referred by the copy of the 763 * blkg. 764 * 765 * On the bright side, destroy operations on a blkg invoke, as 766 * a first step, hooks of the scheduler associated with the 767 * blkg. And these hooks are executed with bfqd->lock held for 768 * BFQ. As a consequence, for any blkg associated with the 769 * request queue this instance of the scheduler is attached 770 * to, we are guaranteed that such a blkg is not destroyed, and 771 * that all the pointers it contains are consistent, while we 772 * are holding bfqd->lock. A blkg_lookup performed with 773 * bfqd->lock held then returns a fully consistent blkg, which 774 * remains consistent until this lock is held. 775 * 776 * Thanks to the last fact, and to the fact that: (1) bfqg has 777 * been obtained through a blkg_lookup in the above 778 * assignment, and (2) bfqd->lock is being held, here we can 779 * safely use the policy data for the involved blkg (i.e., the 780 * field bfqg->pd) to get to the blkg associated with bfqg, 781 * and then we can safely use any field of blkg. After we 782 * release bfqd->lock, even just getting blkg through this 783 * bfqg may cause dangling references to be traversed, as 784 * bfqg->pd may not exist any more. 785 * 786 * In view of the above facts, here we cache, in the bfqg, any 787 * blkg data we may need for this bic, and for its associated 788 * bfq_queue. As of now, we need to cache only the path of the 789 * blkg, which is used in the bfq_log_* functions. 790 * 791 * Finally, note that bfqg itself needs to be protected from 792 * destruction on the blkg_free of the original blkg (which 793 * invokes bfq_pd_free). We use an additional private 794 * refcounter for bfqg, to let it disappear only after no 795 * bfq_queue refers to it any longer. 796 */ 797 blkg_path(bfqg_to_blkg(bfqg), bfqg->blkg_path, sizeof(bfqg->blkg_path)); 798 bic->blkcg_serial_nr = serial_nr; 799 out: 800 rcu_read_unlock(); 801 } 802 803 /** 804 * bfq_flush_idle_tree - deactivate any entity on the idle tree of @st. 805 * @st: the service tree being flushed. 806 */ 807 static void bfq_flush_idle_tree(struct bfq_service_tree *st) 808 { 809 struct bfq_entity *entity = st->first_idle; 810 811 for (; entity ; entity = st->first_idle) 812 __bfq_deactivate_entity(entity, false); 813 } 814 815 /** 816 * bfq_reparent_leaf_entity - move leaf entity to the root_group. 817 * @bfqd: the device data structure with the root group. 818 * @entity: the entity to move, if entity is a leaf; or the parent entity 819 * of an active leaf entity to move, if entity is not a leaf. 820 */ 821 static void bfq_reparent_leaf_entity(struct bfq_data *bfqd, 822 struct bfq_entity *entity, 823 int ioprio_class) 824 { 825 struct bfq_queue *bfqq; 826 struct bfq_entity *child_entity = entity; 827 828 while (child_entity->my_sched_data) { /* leaf not reached yet */ 829 struct bfq_sched_data *child_sd = child_entity->my_sched_data; 830 struct bfq_service_tree *child_st = child_sd->service_tree + 831 ioprio_class; 832 struct rb_root *child_active = &child_st->active; 833 834 child_entity = bfq_entity_of(rb_first(child_active)); 835 836 if (!child_entity) 837 child_entity = child_sd->in_service_entity; 838 } 839 840 bfqq = bfq_entity_to_bfqq(child_entity); 841 bfq_bfqq_move(bfqd, bfqq, bfqd->root_group); 842 } 843 844 /** 845 * bfq_reparent_active_queues - move to the root group all active queues. 846 * @bfqd: the device data structure with the root group. 847 * @bfqg: the group to move from. 848 * @st: the service tree to start the search from. 849 */ 850 static void bfq_reparent_active_queues(struct bfq_data *bfqd, 851 struct bfq_group *bfqg, 852 struct bfq_service_tree *st, 853 int ioprio_class) 854 { 855 struct rb_root *active = &st->active; 856 struct bfq_entity *entity; 857 858 while ((entity = bfq_entity_of(rb_first(active)))) 859 bfq_reparent_leaf_entity(bfqd, entity, ioprio_class); 860 861 if (bfqg->sched_data.in_service_entity) 862 bfq_reparent_leaf_entity(bfqd, 863 bfqg->sched_data.in_service_entity, 864 ioprio_class); 865 } 866 867 /** 868 * bfq_pd_offline - deactivate the entity associated with @pd, 869 * and reparent its children entities. 870 * @pd: descriptor of the policy going offline. 871 * 872 * blkio already grabs the queue_lock for us, so no need to use 873 * RCU-based magic 874 */ 875 static void bfq_pd_offline(struct blkg_policy_data *pd) 876 { 877 struct bfq_service_tree *st; 878 struct bfq_group *bfqg = pd_to_bfqg(pd); 879 struct bfq_data *bfqd = bfqg->bfqd; 880 struct bfq_entity *entity = bfqg->my_entity; 881 unsigned long flags; 882 int i; 883 884 spin_lock_irqsave(&bfqd->lock, flags); 885 886 if (!entity) /* root group */ 887 goto put_async_queues; 888 889 /* 890 * Empty all service_trees belonging to this group before 891 * deactivating the group itself. 892 */ 893 for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) { 894 st = bfqg->sched_data.service_tree + i; 895 896 /* 897 * It may happen that some queues are still active 898 * (busy) upon group destruction (if the corresponding 899 * processes have been forced to terminate). We move 900 * all the leaf entities corresponding to these queues 901 * to the root_group. 902 * Also, it may happen that the group has an entity 903 * in service, which is disconnected from the active 904 * tree: it must be moved, too. 905 * There is no need to put the sync queues, as the 906 * scheduler has taken no reference. 907 */ 908 bfq_reparent_active_queues(bfqd, bfqg, st, i); 909 910 /* 911 * The idle tree may still contain bfq_queues 912 * belonging to exited task because they never 913 * migrated to a different cgroup from the one being 914 * destroyed now. In addition, even 915 * bfq_reparent_active_queues() may happen to add some 916 * entities to the idle tree. It happens if, in some 917 * of the calls to bfq_bfqq_move() performed by 918 * bfq_reparent_active_queues(), the queue to move is 919 * empty and gets expired. 920 */ 921 bfq_flush_idle_tree(st); 922 } 923 924 __bfq_deactivate_entity(entity, false); 925 926 put_async_queues: 927 bfq_put_async_queues(bfqd, bfqg); 928 929 spin_unlock_irqrestore(&bfqd->lock, flags); 930 /* 931 * @blkg is going offline and will be ignored by 932 * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so 933 * that they don't get lost. If IOs complete after this point, the 934 * stats for them will be lost. Oh well... 935 */ 936 bfqg_stats_xfer_dead(bfqg); 937 } 938 939 void bfq_end_wr_async(struct bfq_data *bfqd) 940 { 941 struct blkcg_gq *blkg; 942 943 list_for_each_entry(blkg, &bfqd->queue->blkg_list, q_node) { 944 struct bfq_group *bfqg = blkg_to_bfqg(blkg); 945 946 bfq_end_wr_async_queues(bfqd, bfqg); 947 } 948 bfq_end_wr_async_queues(bfqd, bfqd->root_group); 949 } 950 951 static int bfq_io_show_weight_legacy(struct seq_file *sf, void *v) 952 { 953 struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); 954 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); 955 unsigned int val = 0; 956 957 if (bfqgd) 958 val = bfqgd->weight; 959 960 seq_printf(sf, "%u\n", val); 961 962 return 0; 963 } 964 965 static u64 bfqg_prfill_weight_device(struct seq_file *sf, 966 struct blkg_policy_data *pd, int off) 967 { 968 struct bfq_group *bfqg = pd_to_bfqg(pd); 969 970 if (!bfqg->entity.dev_weight) 971 return 0; 972 return __blkg_prfill_u64(sf, pd, bfqg->entity.dev_weight); 973 } 974 975 static int bfq_io_show_weight(struct seq_file *sf, void *v) 976 { 977 struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); 978 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); 979 980 seq_printf(sf, "default %u\n", bfqgd->weight); 981 blkcg_print_blkgs(sf, blkcg, bfqg_prfill_weight_device, 982 &blkcg_policy_bfq, 0, false); 983 return 0; 984 } 985 986 static void bfq_group_set_weight(struct bfq_group *bfqg, u64 weight, u64 dev_weight) 987 { 988 weight = dev_weight ?: weight; 989 990 bfqg->entity.dev_weight = dev_weight; 991 /* 992 * Setting the prio_changed flag of the entity 993 * to 1 with new_weight == weight would re-set 994 * the value of the weight to its ioprio mapping. 995 * Set the flag only if necessary. 996 */ 997 if ((unsigned short)weight != bfqg->entity.new_weight) { 998 bfqg->entity.new_weight = (unsigned short)weight; 999 /* 1000 * Make sure that the above new value has been 1001 * stored in bfqg->entity.new_weight before 1002 * setting the prio_changed flag. In fact, 1003 * this flag may be read asynchronously (in 1004 * critical sections protected by a different 1005 * lock than that held here), and finding this 1006 * flag set may cause the execution of the code 1007 * for updating parameters whose value may 1008 * depend also on bfqg->entity.new_weight (in 1009 * __bfq_entity_update_weight_prio). 1010 * This barrier makes sure that the new value 1011 * of bfqg->entity.new_weight is correctly 1012 * seen in that code. 1013 */ 1014 smp_wmb(); 1015 bfqg->entity.prio_changed = 1; 1016 } 1017 } 1018 1019 static int bfq_io_set_weight_legacy(struct cgroup_subsys_state *css, 1020 struct cftype *cftype, 1021 u64 val) 1022 { 1023 struct blkcg *blkcg = css_to_blkcg(css); 1024 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); 1025 struct blkcg_gq *blkg; 1026 int ret = -ERANGE; 1027 1028 if (val < BFQ_MIN_WEIGHT || val > BFQ_MAX_WEIGHT) 1029 return ret; 1030 1031 ret = 0; 1032 spin_lock_irq(&blkcg->lock); 1033 bfqgd->weight = (unsigned short)val; 1034 hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { 1035 struct bfq_group *bfqg = blkg_to_bfqg(blkg); 1036 1037 if (bfqg) 1038 bfq_group_set_weight(bfqg, val, 0); 1039 } 1040 spin_unlock_irq(&blkcg->lock); 1041 1042 return ret; 1043 } 1044 1045 static ssize_t bfq_io_set_device_weight(struct kernfs_open_file *of, 1046 char *buf, size_t nbytes, 1047 loff_t off) 1048 { 1049 int ret; 1050 struct blkg_conf_ctx ctx; 1051 struct blkcg *blkcg = css_to_blkcg(of_css(of)); 1052 struct bfq_group *bfqg; 1053 u64 v; 1054 1055 ret = blkg_conf_prep(blkcg, &blkcg_policy_bfq, buf, &ctx); 1056 if (ret) 1057 return ret; 1058 1059 if (sscanf(ctx.body, "%llu", &v) == 1) { 1060 /* require "default" on dfl */ 1061 ret = -ERANGE; 1062 if (!v) 1063 goto out; 1064 } else if (!strcmp(strim(ctx.body), "default")) { 1065 v = 0; 1066 } else { 1067 ret = -EINVAL; 1068 goto out; 1069 } 1070 1071 bfqg = blkg_to_bfqg(ctx.blkg); 1072 1073 ret = -ERANGE; 1074 if (!v || (v >= BFQ_MIN_WEIGHT && v <= BFQ_MAX_WEIGHT)) { 1075 bfq_group_set_weight(bfqg, bfqg->entity.weight, v); 1076 ret = 0; 1077 } 1078 out: 1079 blkg_conf_finish(&ctx); 1080 return ret ?: nbytes; 1081 } 1082 1083 static ssize_t bfq_io_set_weight(struct kernfs_open_file *of, 1084 char *buf, size_t nbytes, 1085 loff_t off) 1086 { 1087 char *endp; 1088 int ret; 1089 u64 v; 1090 1091 buf = strim(buf); 1092 1093 /* "WEIGHT" or "default WEIGHT" sets the default weight */ 1094 v = simple_strtoull(buf, &endp, 0); 1095 if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) { 1096 ret = bfq_io_set_weight_legacy(of_css(of), NULL, v); 1097 return ret ?: nbytes; 1098 } 1099 1100 return bfq_io_set_device_weight(of, buf, nbytes, off); 1101 } 1102 1103 static int bfqg_print_rwstat(struct seq_file *sf, void *v) 1104 { 1105 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat, 1106 &blkcg_policy_bfq, seq_cft(sf)->private, true); 1107 return 0; 1108 } 1109 1110 static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf, 1111 struct blkg_policy_data *pd, int off) 1112 { 1113 struct blkg_rwstat_sample sum; 1114 1115 blkg_rwstat_recursive_sum(pd_to_blkg(pd), &blkcg_policy_bfq, off, &sum); 1116 return __blkg_prfill_rwstat(sf, pd, &sum); 1117 } 1118 1119 static int bfqg_print_rwstat_recursive(struct seq_file *sf, void *v) 1120 { 1121 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1122 bfqg_prfill_rwstat_recursive, &blkcg_policy_bfq, 1123 seq_cft(sf)->private, true); 1124 return 0; 1125 } 1126 1127 #ifdef CONFIG_BFQ_CGROUP_DEBUG 1128 static int bfqg_print_stat(struct seq_file *sf, void *v) 1129 { 1130 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat, 1131 &blkcg_policy_bfq, seq_cft(sf)->private, false); 1132 return 0; 1133 } 1134 1135 static u64 bfqg_prfill_stat_recursive(struct seq_file *sf, 1136 struct blkg_policy_data *pd, int off) 1137 { 1138 struct blkcg_gq *blkg = pd_to_blkg(pd); 1139 struct blkcg_gq *pos_blkg; 1140 struct cgroup_subsys_state *pos_css; 1141 u64 sum = 0; 1142 1143 lockdep_assert_held(&blkg->q->queue_lock); 1144 1145 rcu_read_lock(); 1146 blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { 1147 struct bfq_stat *stat; 1148 1149 if (!pos_blkg->online) 1150 continue; 1151 1152 stat = (void *)blkg_to_pd(pos_blkg, &blkcg_policy_bfq) + off; 1153 sum += bfq_stat_read(stat) + atomic64_read(&stat->aux_cnt); 1154 } 1155 rcu_read_unlock(); 1156 1157 return __blkg_prfill_u64(sf, pd, sum); 1158 } 1159 1160 static int bfqg_print_stat_recursive(struct seq_file *sf, void *v) 1161 { 1162 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1163 bfqg_prfill_stat_recursive, &blkcg_policy_bfq, 1164 seq_cft(sf)->private, false); 1165 return 0; 1166 } 1167 1168 static u64 bfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd, 1169 int off) 1170 { 1171 struct bfq_group *bfqg = blkg_to_bfqg(pd->blkg); 1172 u64 sum = blkg_rwstat_total(&bfqg->stats.bytes); 1173 1174 return __blkg_prfill_u64(sf, pd, sum >> 9); 1175 } 1176 1177 static int bfqg_print_stat_sectors(struct seq_file *sf, void *v) 1178 { 1179 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1180 bfqg_prfill_sectors, &blkcg_policy_bfq, 0, false); 1181 return 0; 1182 } 1183 1184 static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf, 1185 struct blkg_policy_data *pd, int off) 1186 { 1187 struct blkg_rwstat_sample tmp; 1188 1189 blkg_rwstat_recursive_sum(pd->blkg, &blkcg_policy_bfq, 1190 offsetof(struct bfq_group, stats.bytes), &tmp); 1191 1192 return __blkg_prfill_u64(sf, pd, 1193 (tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]) >> 9); 1194 } 1195 1196 static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v) 1197 { 1198 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1199 bfqg_prfill_sectors_recursive, &blkcg_policy_bfq, 0, 1200 false); 1201 return 0; 1202 } 1203 1204 static u64 bfqg_prfill_avg_queue_size(struct seq_file *sf, 1205 struct blkg_policy_data *pd, int off) 1206 { 1207 struct bfq_group *bfqg = pd_to_bfqg(pd); 1208 u64 samples = bfq_stat_read(&bfqg->stats.avg_queue_size_samples); 1209 u64 v = 0; 1210 1211 if (samples) { 1212 v = bfq_stat_read(&bfqg->stats.avg_queue_size_sum); 1213 v = div64_u64(v, samples); 1214 } 1215 __blkg_prfill_u64(sf, pd, v); 1216 return 0; 1217 } 1218 1219 /* print avg_queue_size */ 1220 static int bfqg_print_avg_queue_size(struct seq_file *sf, void *v) 1221 { 1222 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1223 bfqg_prfill_avg_queue_size, &blkcg_policy_bfq, 1224 0, false); 1225 return 0; 1226 } 1227 #endif /* CONFIG_BFQ_CGROUP_DEBUG */ 1228 1229 struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node) 1230 { 1231 int ret; 1232 1233 ret = blkcg_activate_policy(bfqd->queue, &blkcg_policy_bfq); 1234 if (ret) 1235 return NULL; 1236 1237 return blkg_to_bfqg(bfqd->queue->root_blkg); 1238 } 1239 1240 struct blkcg_policy blkcg_policy_bfq = { 1241 .dfl_cftypes = bfq_blkg_files, 1242 .legacy_cftypes = bfq_blkcg_legacy_files, 1243 1244 .cpd_alloc_fn = bfq_cpd_alloc, 1245 .cpd_init_fn = bfq_cpd_init, 1246 .cpd_bind_fn = bfq_cpd_init, 1247 .cpd_free_fn = bfq_cpd_free, 1248 1249 .pd_alloc_fn = bfq_pd_alloc, 1250 .pd_init_fn = bfq_pd_init, 1251 .pd_offline_fn = bfq_pd_offline, 1252 .pd_free_fn = bfq_pd_free, 1253 .pd_reset_stats_fn = bfq_pd_reset_stats, 1254 }; 1255 1256 struct cftype bfq_blkcg_legacy_files[] = { 1257 { 1258 .name = "bfq.weight", 1259 .flags = CFTYPE_NOT_ON_ROOT, 1260 .seq_show = bfq_io_show_weight_legacy, 1261 .write_u64 = bfq_io_set_weight_legacy, 1262 }, 1263 { 1264 .name = "bfq.weight_device", 1265 .flags = CFTYPE_NOT_ON_ROOT, 1266 .seq_show = bfq_io_show_weight, 1267 .write = bfq_io_set_weight, 1268 }, 1269 1270 /* statistics, covers only the tasks in the bfqg */ 1271 { 1272 .name = "bfq.io_service_bytes", 1273 .private = offsetof(struct bfq_group, stats.bytes), 1274 .seq_show = bfqg_print_rwstat, 1275 }, 1276 { 1277 .name = "bfq.io_serviced", 1278 .private = offsetof(struct bfq_group, stats.ios), 1279 .seq_show = bfqg_print_rwstat, 1280 }, 1281 #ifdef CONFIG_BFQ_CGROUP_DEBUG 1282 { 1283 .name = "bfq.time", 1284 .private = offsetof(struct bfq_group, stats.time), 1285 .seq_show = bfqg_print_stat, 1286 }, 1287 { 1288 .name = "bfq.sectors", 1289 .seq_show = bfqg_print_stat_sectors, 1290 }, 1291 { 1292 .name = "bfq.io_service_time", 1293 .private = offsetof(struct bfq_group, stats.service_time), 1294 .seq_show = bfqg_print_rwstat, 1295 }, 1296 { 1297 .name = "bfq.io_wait_time", 1298 .private = offsetof(struct bfq_group, stats.wait_time), 1299 .seq_show = bfqg_print_rwstat, 1300 }, 1301 { 1302 .name = "bfq.io_merged", 1303 .private = offsetof(struct bfq_group, stats.merged), 1304 .seq_show = bfqg_print_rwstat, 1305 }, 1306 { 1307 .name = "bfq.io_queued", 1308 .private = offsetof(struct bfq_group, stats.queued), 1309 .seq_show = bfqg_print_rwstat, 1310 }, 1311 #endif /* CONFIG_BFQ_CGROUP_DEBUG */ 1312 1313 /* the same statistics which cover the bfqg and its descendants */ 1314 { 1315 .name = "bfq.io_service_bytes_recursive", 1316 .private = offsetof(struct bfq_group, stats.bytes), 1317 .seq_show = bfqg_print_rwstat_recursive, 1318 }, 1319 { 1320 .name = "bfq.io_serviced_recursive", 1321 .private = offsetof(struct bfq_group, stats.ios), 1322 .seq_show = bfqg_print_rwstat_recursive, 1323 }, 1324 #ifdef CONFIG_BFQ_CGROUP_DEBUG 1325 { 1326 .name = "bfq.time_recursive", 1327 .private = offsetof(struct bfq_group, stats.time), 1328 .seq_show = bfqg_print_stat_recursive, 1329 }, 1330 { 1331 .name = "bfq.sectors_recursive", 1332 .seq_show = bfqg_print_stat_sectors_recursive, 1333 }, 1334 { 1335 .name = "bfq.io_service_time_recursive", 1336 .private = offsetof(struct bfq_group, stats.service_time), 1337 .seq_show = bfqg_print_rwstat_recursive, 1338 }, 1339 { 1340 .name = "bfq.io_wait_time_recursive", 1341 .private = offsetof(struct bfq_group, stats.wait_time), 1342 .seq_show = bfqg_print_rwstat_recursive, 1343 }, 1344 { 1345 .name = "bfq.io_merged_recursive", 1346 .private = offsetof(struct bfq_group, stats.merged), 1347 .seq_show = bfqg_print_rwstat_recursive, 1348 }, 1349 { 1350 .name = "bfq.io_queued_recursive", 1351 .private = offsetof(struct bfq_group, stats.queued), 1352 .seq_show = bfqg_print_rwstat_recursive, 1353 }, 1354 { 1355 .name = "bfq.avg_queue_size", 1356 .seq_show = bfqg_print_avg_queue_size, 1357 }, 1358 { 1359 .name = "bfq.group_wait_time", 1360 .private = offsetof(struct bfq_group, stats.group_wait_time), 1361 .seq_show = bfqg_print_stat, 1362 }, 1363 { 1364 .name = "bfq.idle_time", 1365 .private = offsetof(struct bfq_group, stats.idle_time), 1366 .seq_show = bfqg_print_stat, 1367 }, 1368 { 1369 .name = "bfq.empty_time", 1370 .private = offsetof(struct bfq_group, stats.empty_time), 1371 .seq_show = bfqg_print_stat, 1372 }, 1373 { 1374 .name = "bfq.dequeue", 1375 .private = offsetof(struct bfq_group, stats.dequeue), 1376 .seq_show = bfqg_print_stat, 1377 }, 1378 #endif /* CONFIG_BFQ_CGROUP_DEBUG */ 1379 { } /* terminate */ 1380 }; 1381 1382 struct cftype bfq_blkg_files[] = { 1383 { 1384 .name = "bfq.weight", 1385 .flags = CFTYPE_NOT_ON_ROOT, 1386 .seq_show = bfq_io_show_weight, 1387 .write = bfq_io_set_weight, 1388 }, 1389 {} /* terminate */ 1390 }; 1391 1392 #else /* CONFIG_BFQ_GROUP_IOSCHED */ 1393 1394 void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, 1395 struct bfq_group *bfqg) {} 1396 1397 void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg) 1398 { 1399 struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); 1400 1401 entity->weight = entity->new_weight; 1402 entity->orig_weight = entity->new_weight; 1403 if (bfqq) { 1404 bfqq->ioprio = bfqq->new_ioprio; 1405 bfqq->ioprio_class = bfqq->new_ioprio_class; 1406 } 1407 entity->sched_data = &bfqg->sched_data; 1408 } 1409 1410 void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) {} 1411 1412 void bfq_end_wr_async(struct bfq_data *bfqd) 1413 { 1414 bfq_end_wr_async_queues(bfqd, bfqd->root_group); 1415 } 1416 1417 struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, struct blkcg *blkcg) 1418 { 1419 return bfqd->root_group; 1420 } 1421 1422 struct bfq_group *bfqq_group(struct bfq_queue *bfqq) 1423 { 1424 return bfqq->bfqd->root_group; 1425 } 1426 1427 void bfqg_and_blkg_get(struct bfq_group *bfqg) {} 1428 1429 void bfqg_and_blkg_put(struct bfq_group *bfqg) {} 1430 1431 struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node) 1432 { 1433 struct bfq_group *bfqg; 1434 int i; 1435 1436 bfqg = kmalloc_node(sizeof(*bfqg), GFP_KERNEL | __GFP_ZERO, node); 1437 if (!bfqg) 1438 return NULL; 1439 1440 for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) 1441 bfqg->sched_data.service_tree[i] = BFQ_SERVICE_TREE_INIT; 1442 1443 return bfqg; 1444 } 1445 #endif /* CONFIG_BFQ_GROUP_IOSCHED */ 1446