1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * cgroups support for the BFQ I/O scheduler. 4 */ 5 #include <linux/module.h> 6 #include <linux/slab.h> 7 #include <linux/blkdev.h> 8 #include <linux/cgroup.h> 9 #include <linux/ktime.h> 10 #include <linux/rbtree.h> 11 #include <linux/ioprio.h> 12 #include <linux/sbitmap.h> 13 #include <linux/delay.h> 14 15 #include "elevator.h" 16 #include "bfq-iosched.h" 17 18 #ifdef CONFIG_BFQ_CGROUP_DEBUG 19 static int bfq_stat_init(struct bfq_stat *stat, gfp_t gfp) 20 { 21 int ret; 22 23 ret = percpu_counter_init(&stat->cpu_cnt, 0, gfp); 24 if (ret) 25 return ret; 26 27 atomic64_set(&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 goto error; 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 goto error; 481 #endif 482 483 return 0; 484 485 error: 486 bfqg_stats_exit(stats); 487 return -ENOMEM; 488 } 489 490 static struct bfq_group_data *cpd_to_bfqgd(struct blkcg_policy_data *cpd) 491 { 492 return cpd ? container_of(cpd, struct bfq_group_data, pd) : NULL; 493 } 494 495 static struct bfq_group_data *blkcg_to_bfqgd(struct blkcg *blkcg) 496 { 497 return cpd_to_bfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_bfq)); 498 } 499 500 static struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp) 501 { 502 struct bfq_group_data *bgd; 503 504 bgd = kzalloc(sizeof(*bgd), gfp); 505 if (!bgd) 506 return NULL; 507 return &bgd->pd; 508 } 509 510 static void bfq_cpd_init(struct blkcg_policy_data *cpd) 511 { 512 struct bfq_group_data *d = cpd_to_bfqgd(cpd); 513 514 d->weight = cgroup_subsys_on_dfl(io_cgrp_subsys) ? 515 CGROUP_WEIGHT_DFL : BFQ_WEIGHT_LEGACY_DFL; 516 } 517 518 static void bfq_cpd_free(struct blkcg_policy_data *cpd) 519 { 520 kfree(cpd_to_bfqgd(cpd)); 521 } 522 523 static struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, struct request_queue *q, 524 struct blkcg *blkcg) 525 { 526 struct bfq_group *bfqg; 527 528 bfqg = kzalloc_node(sizeof(*bfqg), gfp, q->node); 529 if (!bfqg) 530 return NULL; 531 532 if (bfqg_stats_init(&bfqg->stats, gfp)) { 533 kfree(bfqg); 534 return NULL; 535 } 536 537 /* see comments in bfq_bic_update_cgroup for why refcounting */ 538 bfqg_get(bfqg); 539 return &bfqg->pd; 540 } 541 542 static void bfq_pd_init(struct blkg_policy_data *pd) 543 { 544 struct blkcg_gq *blkg = pd_to_blkg(pd); 545 struct bfq_group *bfqg = blkg_to_bfqg(blkg); 546 struct bfq_data *bfqd = blkg->q->elevator->elevator_data; 547 struct bfq_entity *entity = &bfqg->entity; 548 struct bfq_group_data *d = blkcg_to_bfqgd(blkg->blkcg); 549 550 entity->orig_weight = entity->weight = entity->new_weight = d->weight; 551 entity->my_sched_data = &bfqg->sched_data; 552 entity->last_bfqq_created = NULL; 553 554 bfqg->my_entity = entity; /* 555 * the root_group's will be set to NULL 556 * in bfq_init_queue() 557 */ 558 bfqg->bfqd = bfqd; 559 bfqg->active_entities = 0; 560 bfqg->online = true; 561 bfqg->rq_pos_tree = RB_ROOT; 562 } 563 564 static void bfq_pd_free(struct blkg_policy_data *pd) 565 { 566 struct bfq_group *bfqg = pd_to_bfqg(pd); 567 568 bfqg_stats_exit(&bfqg->stats); 569 bfqg_put(bfqg); 570 } 571 572 static void bfq_pd_reset_stats(struct blkg_policy_data *pd) 573 { 574 struct bfq_group *bfqg = pd_to_bfqg(pd); 575 576 bfqg_stats_reset(&bfqg->stats); 577 } 578 579 static void bfq_group_set_parent(struct bfq_group *bfqg, 580 struct bfq_group *parent) 581 { 582 struct bfq_entity *entity; 583 584 entity = &bfqg->entity; 585 entity->parent = parent->my_entity; 586 entity->sched_data = &parent->sched_data; 587 } 588 589 static void bfq_link_bfqg(struct bfq_data *bfqd, struct bfq_group *bfqg) 590 { 591 struct bfq_group *parent; 592 struct bfq_entity *entity; 593 594 /* 595 * Update chain of bfq_groups as we might be handling a leaf group 596 * which, along with some of its relatives, has not been hooked yet 597 * to the private hierarchy of BFQ. 598 */ 599 entity = &bfqg->entity; 600 for_each_entity(entity) { 601 struct bfq_group *curr_bfqg = container_of(entity, 602 struct bfq_group, entity); 603 if (curr_bfqg != bfqd->root_group) { 604 parent = bfqg_parent(curr_bfqg); 605 if (!parent) 606 parent = bfqd->root_group; 607 bfq_group_set_parent(curr_bfqg, parent); 608 } 609 } 610 } 611 612 struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio) 613 { 614 struct blkcg_gq *blkg = bio->bi_blkg; 615 struct bfq_group *bfqg; 616 617 while (blkg) { 618 bfqg = blkg_to_bfqg(blkg); 619 if (bfqg->online) { 620 bio_associate_blkg_from_css(bio, &blkg->blkcg->css); 621 return bfqg; 622 } 623 blkg = blkg->parent; 624 } 625 bio_associate_blkg_from_css(bio, 626 &bfqg_to_blkg(bfqd->root_group)->blkcg->css); 627 return bfqd->root_group; 628 } 629 630 /** 631 * bfq_bfqq_move - migrate @bfqq to @bfqg. 632 * @bfqd: queue descriptor. 633 * @bfqq: the queue to move. 634 * @bfqg: the group to move to. 635 * 636 * Move @bfqq to @bfqg, deactivating it from its old group and reactivating 637 * it on the new one. Avoid putting the entity on the old group idle tree. 638 * 639 * Must be called under the scheduler lock, to make sure that the blkg 640 * owning @bfqg does not disappear (see comments in 641 * bfq_bic_update_cgroup on guaranteeing the consistency of blkg 642 * objects). 643 */ 644 void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, 645 struct bfq_group *bfqg) 646 { 647 struct bfq_entity *entity = &bfqq->entity; 648 struct bfq_group *old_parent = bfqq_group(bfqq); 649 650 /* 651 * No point to move bfqq to the same group, which can happen when 652 * root group is offlined 653 */ 654 if (old_parent == bfqg) 655 return; 656 657 /* 658 * oom_bfqq is not allowed to move, oom_bfqq will hold ref to root_group 659 * until elevator exit. 660 */ 661 if (bfqq == &bfqd->oom_bfqq) 662 return; 663 /* 664 * Get extra reference to prevent bfqq from being freed in 665 * next possible expire or deactivate. 666 */ 667 bfqq->ref++; 668 669 /* If bfqq is empty, then bfq_bfqq_expire also invokes 670 * bfq_del_bfqq_busy, thereby removing bfqq and its entity 671 * from data structures related to current group. Otherwise we 672 * need to remove bfqq explicitly with bfq_deactivate_bfqq, as 673 * we do below. 674 */ 675 if (bfqq == bfqd->in_service_queue) 676 bfq_bfqq_expire(bfqd, bfqd->in_service_queue, 677 false, BFQQE_PREEMPTED); 678 679 if (bfq_bfqq_busy(bfqq)) 680 bfq_deactivate_bfqq(bfqd, bfqq, false, false); 681 else if (entity->on_st_or_in_serv) 682 bfq_put_idle_entity(bfq_entity_service_tree(entity), entity); 683 bfqg_and_blkg_put(old_parent); 684 685 if (entity->parent && 686 entity->parent->last_bfqq_created == bfqq) 687 entity->parent->last_bfqq_created = NULL; 688 else if (bfqd->last_bfqq_created == bfqq) 689 bfqd->last_bfqq_created = NULL; 690 691 entity->parent = bfqg->my_entity; 692 entity->sched_data = &bfqg->sched_data; 693 /* pin down bfqg and its associated blkg */ 694 bfqg_and_blkg_get(bfqg); 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->rq_in_driver) 703 bfq_schedule_dispatch(bfqd); 704 /* release extra ref taken above, bfqq may happen to be freed now */ 705 bfq_put_queue(bfqq); 706 } 707 708 /** 709 * __bfq_bic_change_cgroup - move @bic to @cgroup. 710 * @bfqd: the queue descriptor. 711 * @bic: the bic to move. 712 * @blkcg: the blk-cgroup to move to. 713 * 714 * Move bic to blkcg, assuming that bfqd->lock is held; which makes 715 * sure that the reference to cgroup is valid across the call (see 716 * comments in bfq_bic_update_cgroup on this issue) 717 */ 718 static void *__bfq_bic_change_cgroup(struct bfq_data *bfqd, 719 struct bfq_io_cq *bic, 720 struct bfq_group *bfqg) 721 { 722 struct bfq_queue *async_bfqq = bic_to_bfqq(bic, 0); 723 struct bfq_queue *sync_bfqq = bic_to_bfqq(bic, 1); 724 struct bfq_entity *entity; 725 726 if (async_bfqq) { 727 entity = &async_bfqq->entity; 728 729 if (entity->sched_data != &bfqg->sched_data) { 730 bic_set_bfqq(bic, NULL, 0); 731 bfq_release_process_ref(bfqd, async_bfqq); 732 } 733 } 734 735 if (sync_bfqq) { 736 if (!sync_bfqq->new_bfqq && !bfq_bfqq_coop(sync_bfqq)) { 737 /* We are the only user of this bfqq, just move it */ 738 if (sync_bfqq->entity.sched_data != &bfqg->sched_data) 739 bfq_bfqq_move(bfqd, sync_bfqq, bfqg); 740 } else { 741 struct bfq_queue *bfqq; 742 743 /* 744 * The queue was merged to a different queue. Check 745 * that the merge chain still belongs to the same 746 * cgroup. 747 */ 748 for (bfqq = sync_bfqq; bfqq; bfqq = bfqq->new_bfqq) 749 if (bfqq->entity.sched_data != 750 &bfqg->sched_data) 751 break; 752 if (bfqq) { 753 /* 754 * Some queue changed cgroup so the merge is 755 * not valid anymore. We cannot easily just 756 * cancel the merge (by clearing new_bfqq) as 757 * there may be other processes using this 758 * queue and holding refs to all queues below 759 * sync_bfqq->new_bfqq. Similarly if the merge 760 * already happened, we need to detach from 761 * bfqq now so that we cannot merge bio to a 762 * request from the old cgroup. 763 */ 764 bfq_put_cooperator(sync_bfqq); 765 bfq_release_process_ref(bfqd, sync_bfqq); 766 bic_set_bfqq(bic, NULL, 1); 767 } 768 } 769 } 770 771 return bfqg; 772 } 773 774 void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) 775 { 776 struct bfq_data *bfqd = bic_to_bfqd(bic); 777 struct bfq_group *bfqg = bfq_bio_bfqg(bfqd, bio); 778 uint64_t serial_nr; 779 780 serial_nr = bfqg_to_blkg(bfqg)->blkcg->css.serial_nr; 781 782 /* 783 * Check whether blkcg has changed. The condition may trigger 784 * spuriously on a newly created cic but there's no harm. 785 */ 786 if (unlikely(!bfqd) || likely(bic->blkcg_serial_nr == serial_nr)) 787 return; 788 789 /* 790 * New cgroup for this process. Make sure it is linked to bfq internal 791 * cgroup hierarchy. 792 */ 793 bfq_link_bfqg(bfqd, bfqg); 794 __bfq_bic_change_cgroup(bfqd, bic, bfqg); 795 /* 796 * Update blkg_path for bfq_log_* functions. We cache this 797 * path, and update it here, for the following 798 * reasons. Operations on blkg objects in blk-cgroup are 799 * protected with the request_queue lock, and not with the 800 * lock that protects the instances of this scheduler 801 * (bfqd->lock). This exposes BFQ to the following sort of 802 * race. 803 * 804 * The blkg_lookup performed in bfq_get_queue, protected 805 * through rcu, may happen to return the address of a copy of 806 * the original blkg. If this is the case, then the 807 * bfqg_and_blkg_get performed in bfq_get_queue, to pin down 808 * the blkg, is useless: it does not prevent blk-cgroup code 809 * from destroying both the original blkg and all objects 810 * directly or indirectly referred by the copy of the 811 * blkg. 812 * 813 * On the bright side, destroy operations on a blkg invoke, as 814 * a first step, hooks of the scheduler associated with the 815 * blkg. And these hooks are executed with bfqd->lock held for 816 * BFQ. As a consequence, for any blkg associated with the 817 * request queue this instance of the scheduler is attached 818 * to, we are guaranteed that such a blkg is not destroyed, and 819 * that all the pointers it contains are consistent, while we 820 * are holding bfqd->lock. A blkg_lookup performed with 821 * bfqd->lock held then returns a fully consistent blkg, which 822 * remains consistent until this lock is held. 823 * 824 * Thanks to the last fact, and to the fact that: (1) bfqg has 825 * been obtained through a blkg_lookup in the above 826 * assignment, and (2) bfqd->lock is being held, here we can 827 * safely use the policy data for the involved blkg (i.e., the 828 * field bfqg->pd) to get to the blkg associated with bfqg, 829 * and then we can safely use any field of blkg. After we 830 * release bfqd->lock, even just getting blkg through this 831 * bfqg may cause dangling references to be traversed, as 832 * bfqg->pd may not exist any more. 833 * 834 * In view of the above facts, here we cache, in the bfqg, any 835 * blkg data we may need for this bic, and for its associated 836 * bfq_queue. As of now, we need to cache only the path of the 837 * blkg, which is used in the bfq_log_* functions. 838 * 839 * Finally, note that bfqg itself needs to be protected from 840 * destruction on the blkg_free of the original blkg (which 841 * invokes bfq_pd_free). We use an additional private 842 * refcounter for bfqg, to let it disappear only after no 843 * bfq_queue refers to it any longer. 844 */ 845 blkg_path(bfqg_to_blkg(bfqg), bfqg->blkg_path, sizeof(bfqg->blkg_path)); 846 bic->blkcg_serial_nr = serial_nr; 847 } 848 849 /** 850 * bfq_flush_idle_tree - deactivate any entity on the idle tree of @st. 851 * @st: the service tree being flushed. 852 */ 853 static void bfq_flush_idle_tree(struct bfq_service_tree *st) 854 { 855 struct bfq_entity *entity = st->first_idle; 856 857 for (; entity ; entity = st->first_idle) 858 __bfq_deactivate_entity(entity, false); 859 } 860 861 /** 862 * bfq_reparent_leaf_entity - move leaf entity to the root_group. 863 * @bfqd: the device data structure with the root group. 864 * @entity: the entity to move, if entity is a leaf; or the parent entity 865 * of an active leaf entity to move, if entity is not a leaf. 866 */ 867 static void bfq_reparent_leaf_entity(struct bfq_data *bfqd, 868 struct bfq_entity *entity, 869 int ioprio_class) 870 { 871 struct bfq_queue *bfqq; 872 struct bfq_entity *child_entity = entity; 873 874 while (child_entity->my_sched_data) { /* leaf not reached yet */ 875 struct bfq_sched_data *child_sd = child_entity->my_sched_data; 876 struct bfq_service_tree *child_st = child_sd->service_tree + 877 ioprio_class; 878 struct rb_root *child_active = &child_st->active; 879 880 child_entity = bfq_entity_of(rb_first(child_active)); 881 882 if (!child_entity) 883 child_entity = child_sd->in_service_entity; 884 } 885 886 bfqq = bfq_entity_to_bfqq(child_entity); 887 bfq_bfqq_move(bfqd, bfqq, bfqd->root_group); 888 } 889 890 /** 891 * bfq_reparent_active_queues - move to the root group all active queues. 892 * @bfqd: the device data structure with the root group. 893 * @bfqg: the group to move from. 894 * @st: the service tree to start the search from. 895 */ 896 static void bfq_reparent_active_queues(struct bfq_data *bfqd, 897 struct bfq_group *bfqg, 898 struct bfq_service_tree *st, 899 int ioprio_class) 900 { 901 struct rb_root *active = &st->active; 902 struct bfq_entity *entity; 903 904 while ((entity = bfq_entity_of(rb_first(active)))) 905 bfq_reparent_leaf_entity(bfqd, entity, ioprio_class); 906 907 if (bfqg->sched_data.in_service_entity) 908 bfq_reparent_leaf_entity(bfqd, 909 bfqg->sched_data.in_service_entity, 910 ioprio_class); 911 } 912 913 /** 914 * bfq_pd_offline - deactivate the entity associated with @pd, 915 * and reparent its children entities. 916 * @pd: descriptor of the policy going offline. 917 * 918 * blkio already grabs the queue_lock for us, so no need to use 919 * RCU-based magic 920 */ 921 static void bfq_pd_offline(struct blkg_policy_data *pd) 922 { 923 struct bfq_service_tree *st; 924 struct bfq_group *bfqg = pd_to_bfqg(pd); 925 struct bfq_data *bfqd = bfqg->bfqd; 926 struct bfq_entity *entity = bfqg->my_entity; 927 unsigned long flags; 928 int i; 929 930 spin_lock_irqsave(&bfqd->lock, flags); 931 932 if (!entity) /* root group */ 933 goto put_async_queues; 934 935 /* 936 * Empty all service_trees belonging to this group before 937 * deactivating the group itself. 938 */ 939 for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) { 940 st = bfqg->sched_data.service_tree + i; 941 942 /* 943 * It may happen that some queues are still active 944 * (busy) upon group destruction (if the corresponding 945 * processes have been forced to terminate). We move 946 * all the leaf entities corresponding to these queues 947 * to the root_group. 948 * Also, it may happen that the group has an entity 949 * in service, which is disconnected from the active 950 * tree: it must be moved, too. 951 * There is no need to put the sync queues, as the 952 * scheduler has taken no reference. 953 */ 954 bfq_reparent_active_queues(bfqd, bfqg, st, i); 955 956 /* 957 * The idle tree may still contain bfq_queues 958 * belonging to exited task because they never 959 * migrated to a different cgroup from the one being 960 * destroyed now. In addition, even 961 * bfq_reparent_active_queues() may happen to add some 962 * entities to the idle tree. It happens if, in some 963 * of the calls to bfq_bfqq_move() performed by 964 * bfq_reparent_active_queues(), the queue to move is 965 * empty and gets expired. 966 */ 967 bfq_flush_idle_tree(st); 968 } 969 970 __bfq_deactivate_entity(entity, false); 971 972 put_async_queues: 973 bfq_put_async_queues(bfqd, bfqg); 974 bfqg->online = false; 975 976 spin_unlock_irqrestore(&bfqd->lock, flags); 977 /* 978 * @blkg is going offline and will be ignored by 979 * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so 980 * that they don't get lost. If IOs complete after this point, the 981 * stats for them will be lost. Oh well... 982 */ 983 bfqg_stats_xfer_dead(bfqg); 984 } 985 986 void bfq_end_wr_async(struct bfq_data *bfqd) 987 { 988 struct blkcg_gq *blkg; 989 990 list_for_each_entry(blkg, &bfqd->queue->blkg_list, q_node) { 991 struct bfq_group *bfqg = blkg_to_bfqg(blkg); 992 993 bfq_end_wr_async_queues(bfqd, bfqg); 994 } 995 bfq_end_wr_async_queues(bfqd, bfqd->root_group); 996 } 997 998 static int bfq_io_show_weight_legacy(struct seq_file *sf, void *v) 999 { 1000 struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); 1001 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); 1002 unsigned int val = 0; 1003 1004 if (bfqgd) 1005 val = bfqgd->weight; 1006 1007 seq_printf(sf, "%u\n", val); 1008 1009 return 0; 1010 } 1011 1012 static u64 bfqg_prfill_weight_device(struct seq_file *sf, 1013 struct blkg_policy_data *pd, int off) 1014 { 1015 struct bfq_group *bfqg = pd_to_bfqg(pd); 1016 1017 if (!bfqg->entity.dev_weight) 1018 return 0; 1019 return __blkg_prfill_u64(sf, pd, bfqg->entity.dev_weight); 1020 } 1021 1022 static int bfq_io_show_weight(struct seq_file *sf, void *v) 1023 { 1024 struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); 1025 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); 1026 1027 seq_printf(sf, "default %u\n", bfqgd->weight); 1028 blkcg_print_blkgs(sf, blkcg, bfqg_prfill_weight_device, 1029 &blkcg_policy_bfq, 0, false); 1030 return 0; 1031 } 1032 1033 static void bfq_group_set_weight(struct bfq_group *bfqg, u64 weight, u64 dev_weight) 1034 { 1035 weight = dev_weight ?: weight; 1036 1037 bfqg->entity.dev_weight = dev_weight; 1038 /* 1039 * Setting the prio_changed flag of the entity 1040 * to 1 with new_weight == weight would re-set 1041 * the value of the weight to its ioprio mapping. 1042 * Set the flag only if necessary. 1043 */ 1044 if ((unsigned short)weight != bfqg->entity.new_weight) { 1045 bfqg->entity.new_weight = (unsigned short)weight; 1046 /* 1047 * Make sure that the above new value has been 1048 * stored in bfqg->entity.new_weight before 1049 * setting the prio_changed flag. In fact, 1050 * this flag may be read asynchronously (in 1051 * critical sections protected by a different 1052 * lock than that held here), and finding this 1053 * flag set may cause the execution of the code 1054 * for updating parameters whose value may 1055 * depend also on bfqg->entity.new_weight (in 1056 * __bfq_entity_update_weight_prio). 1057 * This barrier makes sure that the new value 1058 * of bfqg->entity.new_weight is correctly 1059 * seen in that code. 1060 */ 1061 smp_wmb(); 1062 bfqg->entity.prio_changed = 1; 1063 } 1064 } 1065 1066 static int bfq_io_set_weight_legacy(struct cgroup_subsys_state *css, 1067 struct cftype *cftype, 1068 u64 val) 1069 { 1070 struct blkcg *blkcg = css_to_blkcg(css); 1071 struct bfq_group_data *bfqgd = blkcg_to_bfqgd(blkcg); 1072 struct blkcg_gq *blkg; 1073 int ret = -ERANGE; 1074 1075 if (val < BFQ_MIN_WEIGHT || val > BFQ_MAX_WEIGHT) 1076 return ret; 1077 1078 ret = 0; 1079 spin_lock_irq(&blkcg->lock); 1080 bfqgd->weight = (unsigned short)val; 1081 hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { 1082 struct bfq_group *bfqg = blkg_to_bfqg(blkg); 1083 1084 if (bfqg) 1085 bfq_group_set_weight(bfqg, val, 0); 1086 } 1087 spin_unlock_irq(&blkcg->lock); 1088 1089 return ret; 1090 } 1091 1092 static ssize_t bfq_io_set_device_weight(struct kernfs_open_file *of, 1093 char *buf, size_t nbytes, 1094 loff_t off) 1095 { 1096 int ret; 1097 struct blkg_conf_ctx ctx; 1098 struct blkcg *blkcg = css_to_blkcg(of_css(of)); 1099 struct bfq_group *bfqg; 1100 u64 v; 1101 1102 ret = blkg_conf_prep(blkcg, &blkcg_policy_bfq, buf, &ctx); 1103 if (ret) 1104 return ret; 1105 1106 if (sscanf(ctx.body, "%llu", &v) == 1) { 1107 /* require "default" on dfl */ 1108 ret = -ERANGE; 1109 if (!v) 1110 goto out; 1111 } else if (!strcmp(strim(ctx.body), "default")) { 1112 v = 0; 1113 } else { 1114 ret = -EINVAL; 1115 goto out; 1116 } 1117 1118 bfqg = blkg_to_bfqg(ctx.blkg); 1119 1120 ret = -ERANGE; 1121 if (!v || (v >= BFQ_MIN_WEIGHT && v <= BFQ_MAX_WEIGHT)) { 1122 bfq_group_set_weight(bfqg, bfqg->entity.weight, v); 1123 ret = 0; 1124 } 1125 out: 1126 blkg_conf_finish(&ctx); 1127 return ret ?: nbytes; 1128 } 1129 1130 static ssize_t bfq_io_set_weight(struct kernfs_open_file *of, 1131 char *buf, size_t nbytes, 1132 loff_t off) 1133 { 1134 char *endp; 1135 int ret; 1136 u64 v; 1137 1138 buf = strim(buf); 1139 1140 /* "WEIGHT" or "default WEIGHT" sets the default weight */ 1141 v = simple_strtoull(buf, &endp, 0); 1142 if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) { 1143 ret = bfq_io_set_weight_legacy(of_css(of), NULL, v); 1144 return ret ?: nbytes; 1145 } 1146 1147 return bfq_io_set_device_weight(of, buf, nbytes, off); 1148 } 1149 1150 static int bfqg_print_rwstat(struct seq_file *sf, void *v) 1151 { 1152 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat, 1153 &blkcg_policy_bfq, seq_cft(sf)->private, true); 1154 return 0; 1155 } 1156 1157 static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf, 1158 struct blkg_policy_data *pd, int off) 1159 { 1160 struct blkg_rwstat_sample sum; 1161 1162 blkg_rwstat_recursive_sum(pd_to_blkg(pd), &blkcg_policy_bfq, off, &sum); 1163 return __blkg_prfill_rwstat(sf, pd, &sum); 1164 } 1165 1166 static int bfqg_print_rwstat_recursive(struct seq_file *sf, void *v) 1167 { 1168 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1169 bfqg_prfill_rwstat_recursive, &blkcg_policy_bfq, 1170 seq_cft(sf)->private, true); 1171 return 0; 1172 } 1173 1174 #ifdef CONFIG_BFQ_CGROUP_DEBUG 1175 static int bfqg_print_stat(struct seq_file *sf, void *v) 1176 { 1177 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat, 1178 &blkcg_policy_bfq, seq_cft(sf)->private, false); 1179 return 0; 1180 } 1181 1182 static u64 bfqg_prfill_stat_recursive(struct seq_file *sf, 1183 struct blkg_policy_data *pd, int off) 1184 { 1185 struct blkcg_gq *blkg = pd_to_blkg(pd); 1186 struct blkcg_gq *pos_blkg; 1187 struct cgroup_subsys_state *pos_css; 1188 u64 sum = 0; 1189 1190 lockdep_assert_held(&blkg->q->queue_lock); 1191 1192 rcu_read_lock(); 1193 blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { 1194 struct bfq_stat *stat; 1195 1196 if (!pos_blkg->online) 1197 continue; 1198 1199 stat = (void *)blkg_to_pd(pos_blkg, &blkcg_policy_bfq) + off; 1200 sum += bfq_stat_read(stat) + atomic64_read(&stat->aux_cnt); 1201 } 1202 rcu_read_unlock(); 1203 1204 return __blkg_prfill_u64(sf, pd, sum); 1205 } 1206 1207 static int bfqg_print_stat_recursive(struct seq_file *sf, void *v) 1208 { 1209 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1210 bfqg_prfill_stat_recursive, &blkcg_policy_bfq, 1211 seq_cft(sf)->private, false); 1212 return 0; 1213 } 1214 1215 static u64 bfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd, 1216 int off) 1217 { 1218 struct bfq_group *bfqg = blkg_to_bfqg(pd->blkg); 1219 u64 sum = blkg_rwstat_total(&bfqg->stats.bytes); 1220 1221 return __blkg_prfill_u64(sf, pd, sum >> 9); 1222 } 1223 1224 static int bfqg_print_stat_sectors(struct seq_file *sf, void *v) 1225 { 1226 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1227 bfqg_prfill_sectors, &blkcg_policy_bfq, 0, false); 1228 return 0; 1229 } 1230 1231 static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf, 1232 struct blkg_policy_data *pd, int off) 1233 { 1234 struct blkg_rwstat_sample tmp; 1235 1236 blkg_rwstat_recursive_sum(pd->blkg, &blkcg_policy_bfq, 1237 offsetof(struct bfq_group, stats.bytes), &tmp); 1238 1239 return __blkg_prfill_u64(sf, pd, 1240 (tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]) >> 9); 1241 } 1242 1243 static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v) 1244 { 1245 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1246 bfqg_prfill_sectors_recursive, &blkcg_policy_bfq, 0, 1247 false); 1248 return 0; 1249 } 1250 1251 static u64 bfqg_prfill_avg_queue_size(struct seq_file *sf, 1252 struct blkg_policy_data *pd, int off) 1253 { 1254 struct bfq_group *bfqg = pd_to_bfqg(pd); 1255 u64 samples = bfq_stat_read(&bfqg->stats.avg_queue_size_samples); 1256 u64 v = 0; 1257 1258 if (samples) { 1259 v = bfq_stat_read(&bfqg->stats.avg_queue_size_sum); 1260 v = div64_u64(v, samples); 1261 } 1262 __blkg_prfill_u64(sf, pd, v); 1263 return 0; 1264 } 1265 1266 /* print avg_queue_size */ 1267 static int bfqg_print_avg_queue_size(struct seq_file *sf, void *v) 1268 { 1269 blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), 1270 bfqg_prfill_avg_queue_size, &blkcg_policy_bfq, 1271 0, false); 1272 return 0; 1273 } 1274 #endif /* CONFIG_BFQ_CGROUP_DEBUG */ 1275 1276 struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node) 1277 { 1278 int ret; 1279 1280 ret = blkcg_activate_policy(bfqd->queue, &blkcg_policy_bfq); 1281 if (ret) 1282 return NULL; 1283 1284 return blkg_to_bfqg(bfqd->queue->root_blkg); 1285 } 1286 1287 struct blkcg_policy blkcg_policy_bfq = { 1288 .dfl_cftypes = bfq_blkg_files, 1289 .legacy_cftypes = bfq_blkcg_legacy_files, 1290 1291 .cpd_alloc_fn = bfq_cpd_alloc, 1292 .cpd_init_fn = bfq_cpd_init, 1293 .cpd_bind_fn = bfq_cpd_init, 1294 .cpd_free_fn = bfq_cpd_free, 1295 1296 .pd_alloc_fn = bfq_pd_alloc, 1297 .pd_init_fn = bfq_pd_init, 1298 .pd_offline_fn = bfq_pd_offline, 1299 .pd_free_fn = bfq_pd_free, 1300 .pd_reset_stats_fn = bfq_pd_reset_stats, 1301 }; 1302 1303 struct cftype bfq_blkcg_legacy_files[] = { 1304 { 1305 .name = "bfq.weight", 1306 .flags = CFTYPE_NOT_ON_ROOT, 1307 .seq_show = bfq_io_show_weight_legacy, 1308 .write_u64 = bfq_io_set_weight_legacy, 1309 }, 1310 { 1311 .name = "bfq.weight_device", 1312 .flags = CFTYPE_NOT_ON_ROOT, 1313 .seq_show = bfq_io_show_weight, 1314 .write = bfq_io_set_weight, 1315 }, 1316 1317 /* statistics, covers only the tasks in the bfqg */ 1318 { 1319 .name = "bfq.io_service_bytes", 1320 .private = offsetof(struct bfq_group, stats.bytes), 1321 .seq_show = bfqg_print_rwstat, 1322 }, 1323 { 1324 .name = "bfq.io_serviced", 1325 .private = offsetof(struct bfq_group, stats.ios), 1326 .seq_show = bfqg_print_rwstat, 1327 }, 1328 #ifdef CONFIG_BFQ_CGROUP_DEBUG 1329 { 1330 .name = "bfq.time", 1331 .private = offsetof(struct bfq_group, stats.time), 1332 .seq_show = bfqg_print_stat, 1333 }, 1334 { 1335 .name = "bfq.sectors", 1336 .seq_show = bfqg_print_stat_sectors, 1337 }, 1338 { 1339 .name = "bfq.io_service_time", 1340 .private = offsetof(struct bfq_group, stats.service_time), 1341 .seq_show = bfqg_print_rwstat, 1342 }, 1343 { 1344 .name = "bfq.io_wait_time", 1345 .private = offsetof(struct bfq_group, stats.wait_time), 1346 .seq_show = bfqg_print_rwstat, 1347 }, 1348 { 1349 .name = "bfq.io_merged", 1350 .private = offsetof(struct bfq_group, stats.merged), 1351 .seq_show = bfqg_print_rwstat, 1352 }, 1353 { 1354 .name = "bfq.io_queued", 1355 .private = offsetof(struct bfq_group, stats.queued), 1356 .seq_show = bfqg_print_rwstat, 1357 }, 1358 #endif /* CONFIG_BFQ_CGROUP_DEBUG */ 1359 1360 /* the same statistics which cover the bfqg and its descendants */ 1361 { 1362 .name = "bfq.io_service_bytes_recursive", 1363 .private = offsetof(struct bfq_group, stats.bytes), 1364 .seq_show = bfqg_print_rwstat_recursive, 1365 }, 1366 { 1367 .name = "bfq.io_serviced_recursive", 1368 .private = offsetof(struct bfq_group, stats.ios), 1369 .seq_show = bfqg_print_rwstat_recursive, 1370 }, 1371 #ifdef CONFIG_BFQ_CGROUP_DEBUG 1372 { 1373 .name = "bfq.time_recursive", 1374 .private = offsetof(struct bfq_group, stats.time), 1375 .seq_show = bfqg_print_stat_recursive, 1376 }, 1377 { 1378 .name = "bfq.sectors_recursive", 1379 .seq_show = bfqg_print_stat_sectors_recursive, 1380 }, 1381 { 1382 .name = "bfq.io_service_time_recursive", 1383 .private = offsetof(struct bfq_group, stats.service_time), 1384 .seq_show = bfqg_print_rwstat_recursive, 1385 }, 1386 { 1387 .name = "bfq.io_wait_time_recursive", 1388 .private = offsetof(struct bfq_group, stats.wait_time), 1389 .seq_show = bfqg_print_rwstat_recursive, 1390 }, 1391 { 1392 .name = "bfq.io_merged_recursive", 1393 .private = offsetof(struct bfq_group, stats.merged), 1394 .seq_show = bfqg_print_rwstat_recursive, 1395 }, 1396 { 1397 .name = "bfq.io_queued_recursive", 1398 .private = offsetof(struct bfq_group, stats.queued), 1399 .seq_show = bfqg_print_rwstat_recursive, 1400 }, 1401 { 1402 .name = "bfq.avg_queue_size", 1403 .seq_show = bfqg_print_avg_queue_size, 1404 }, 1405 { 1406 .name = "bfq.group_wait_time", 1407 .private = offsetof(struct bfq_group, stats.group_wait_time), 1408 .seq_show = bfqg_print_stat, 1409 }, 1410 { 1411 .name = "bfq.idle_time", 1412 .private = offsetof(struct bfq_group, stats.idle_time), 1413 .seq_show = bfqg_print_stat, 1414 }, 1415 { 1416 .name = "bfq.empty_time", 1417 .private = offsetof(struct bfq_group, stats.empty_time), 1418 .seq_show = bfqg_print_stat, 1419 }, 1420 { 1421 .name = "bfq.dequeue", 1422 .private = offsetof(struct bfq_group, stats.dequeue), 1423 .seq_show = bfqg_print_stat, 1424 }, 1425 #endif /* CONFIG_BFQ_CGROUP_DEBUG */ 1426 { } /* terminate */ 1427 }; 1428 1429 struct cftype bfq_blkg_files[] = { 1430 { 1431 .name = "bfq.weight", 1432 .flags = CFTYPE_NOT_ON_ROOT, 1433 .seq_show = bfq_io_show_weight, 1434 .write = bfq_io_set_weight, 1435 }, 1436 {} /* terminate */ 1437 }; 1438 1439 #else /* CONFIG_BFQ_GROUP_IOSCHED */ 1440 1441 void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, 1442 struct bfq_group *bfqg) {} 1443 1444 void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg) 1445 { 1446 struct bfq_queue *bfqq = bfq_entity_to_bfqq(entity); 1447 1448 entity->weight = entity->new_weight; 1449 entity->orig_weight = entity->new_weight; 1450 if (bfqq) { 1451 bfqq->ioprio = bfqq->new_ioprio; 1452 bfqq->ioprio_class = bfqq->new_ioprio_class; 1453 } 1454 entity->sched_data = &bfqg->sched_data; 1455 } 1456 1457 void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) {} 1458 1459 void bfq_end_wr_async(struct bfq_data *bfqd) 1460 { 1461 bfq_end_wr_async_queues(bfqd, bfqd->root_group); 1462 } 1463 1464 struct bfq_group *bfq_bio_bfqg(struct bfq_data *bfqd, struct bio *bio) 1465 { 1466 return bfqd->root_group; 1467 } 1468 1469 struct bfq_group *bfqq_group(struct bfq_queue *bfqq) 1470 { 1471 return bfqq->bfqd->root_group; 1472 } 1473 1474 void bfqg_and_blkg_get(struct bfq_group *bfqg) {} 1475 1476 void bfqg_and_blkg_put(struct bfq_group *bfqg) {} 1477 1478 struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node) 1479 { 1480 struct bfq_group *bfqg; 1481 int i; 1482 1483 bfqg = kmalloc_node(sizeof(*bfqg), GFP_KERNEL | __GFP_ZERO, node); 1484 if (!bfqg) 1485 return NULL; 1486 1487 for (i = 0; i < BFQ_IOPRIO_CLASSES; i++) 1488 bfqg->sched_data.service_tree[i] = BFQ_SERVICE_TREE_INIT; 1489 1490 return bfqg; 1491 } 1492 #endif /* CONFIG_BFQ_GROUP_IOSCHED */ 1493