1bd166ef1SJens Axboe /* 2bd166ef1SJens Axboe * blk-mq scheduling framework 3bd166ef1SJens Axboe * 4bd166ef1SJens Axboe * Copyright (C) 2016 Jens Axboe 5bd166ef1SJens Axboe */ 6bd166ef1SJens Axboe #include <linux/kernel.h> 7bd166ef1SJens Axboe #include <linux/module.h> 8bd166ef1SJens Axboe #include <linux/blk-mq.h> 9bd166ef1SJens Axboe 10bd166ef1SJens Axboe #include <trace/events/block.h> 11bd166ef1SJens Axboe 12bd166ef1SJens Axboe #include "blk.h" 13bd166ef1SJens Axboe #include "blk-mq.h" 14d332ce09SOmar Sandoval #include "blk-mq-debugfs.h" 15bd166ef1SJens Axboe #include "blk-mq-sched.h" 16bd166ef1SJens Axboe #include "blk-mq-tag.h" 17bd166ef1SJens Axboe #include "blk-wbt.h" 18bd166ef1SJens Axboe 19bd166ef1SJens Axboe void blk_mq_sched_free_hctx_data(struct request_queue *q, 20bd166ef1SJens Axboe void (*exit)(struct blk_mq_hw_ctx *)) 21bd166ef1SJens Axboe { 22bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx; 23bd166ef1SJens Axboe int i; 24bd166ef1SJens Axboe 25bd166ef1SJens Axboe queue_for_each_hw_ctx(q, hctx, i) { 26bd166ef1SJens Axboe if (exit && hctx->sched_data) 27bd166ef1SJens Axboe exit(hctx); 28bd166ef1SJens Axboe kfree(hctx->sched_data); 29bd166ef1SJens Axboe hctx->sched_data = NULL; 30bd166ef1SJens Axboe } 31bd166ef1SJens Axboe } 32bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data); 33bd166ef1SJens Axboe 34e2b3fa5aSDamien Le Moal void blk_mq_sched_assign_ioc(struct request *rq) 35bd166ef1SJens Axboe { 3644e8c2bfSChristoph Hellwig struct request_queue *q = rq->q; 370c62bff1SJens Axboe struct io_context *ioc; 38bd166ef1SJens Axboe struct io_cq *icq; 39bd166ef1SJens Axboe 400c62bff1SJens Axboe /* 410c62bff1SJens Axboe * May not have an IO context if it's a passthrough request 420c62bff1SJens Axboe */ 430c62bff1SJens Axboe ioc = current->io_context; 440c62bff1SJens Axboe if (!ioc) 450c62bff1SJens Axboe return; 460c62bff1SJens Axboe 470d945c1fSChristoph Hellwig spin_lock_irq(&q->queue_lock); 48bd166ef1SJens Axboe icq = ioc_lookup_icq(ioc, q); 490d945c1fSChristoph Hellwig spin_unlock_irq(&q->queue_lock); 50bd166ef1SJens Axboe 51bd166ef1SJens Axboe if (!icq) { 52bd166ef1SJens Axboe icq = ioc_create_icq(ioc, q, GFP_ATOMIC); 53bd166ef1SJens Axboe if (!icq) 54bd166ef1SJens Axboe return; 55bd166ef1SJens Axboe } 56ea511e3cSChristoph Hellwig get_io_context(icq->ioc); 5744e8c2bfSChristoph Hellwig rq->elv.icq = icq; 58bd166ef1SJens Axboe } 59bd166ef1SJens Axboe 608e8320c9SJens Axboe /* 618e8320c9SJens Axboe * Mark a hardware queue as needing a restart. For shared queues, maintain 628e8320c9SJens Axboe * a count of how many hardware queues are marked for restart. 638e8320c9SJens Axboe */ 648e8320c9SJens Axboe static void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx) 658e8320c9SJens Axboe { 668e8320c9SJens Axboe if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) 678e8320c9SJens Axboe return; 688e8320c9SJens Axboe 698e8320c9SJens Axboe set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); 708e8320c9SJens Axboe } 718e8320c9SJens Axboe 7297889f9aSMing Lei void blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx) 738e8320c9SJens Axboe { 748e8320c9SJens Axboe if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) 7597889f9aSMing Lei return; 768e8320c9SJens Axboe clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); 778e8320c9SJens Axboe 7897889f9aSMing Lei blk_mq_run_hw_queue(hctx, true); 798e8320c9SJens Axboe } 808e8320c9SJens Axboe 811f460b63SMing Lei /* 821f460b63SMing Lei * Only SCSI implements .get_budget and .put_budget, and SCSI restarts 831f460b63SMing Lei * its queue by itself in its completion handler, so we don't need to 841f460b63SMing Lei * restart queue if .get_budget() returns BLK_STS_NO_RESOURCE. 851f460b63SMing Lei */ 861f460b63SMing Lei static void blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) 87caf8eb0dSMing Lei { 88caf8eb0dSMing Lei struct request_queue *q = hctx->queue; 89caf8eb0dSMing Lei struct elevator_queue *e = q->elevator; 90caf8eb0dSMing Lei LIST_HEAD(rq_list); 91caf8eb0dSMing Lei 92caf8eb0dSMing Lei do { 93de148297SMing Lei struct request *rq; 94caf8eb0dSMing Lei 95f9cd4bfeSJens Axboe if (e->type->ops.has_work && !e->type->ops.has_work(hctx)) 96caf8eb0dSMing Lei break; 97de148297SMing Lei 9888022d72SMing Lei if (!blk_mq_get_dispatch_budget(hctx)) 991f460b63SMing Lei break; 100de148297SMing Lei 101f9cd4bfeSJens Axboe rq = e->type->ops.dispatch_request(hctx); 102de148297SMing Lei if (!rq) { 103de148297SMing Lei blk_mq_put_dispatch_budget(hctx); 104de148297SMing Lei break; 105caf8eb0dSMing Lei } 106caf8eb0dSMing Lei 107de148297SMing Lei /* 108de148297SMing Lei * Now this rq owns the budget which has to be released 109de148297SMing Lei * if this rq won't be queued to driver via .queue_rq() 110de148297SMing Lei * in blk_mq_dispatch_rq_list(). 111de148297SMing Lei */ 112de148297SMing Lei list_add(&rq->queuelist, &rq_list); 113de148297SMing Lei } while (blk_mq_dispatch_rq_list(q, &rq_list, true)); 114de148297SMing Lei } 115de148297SMing Lei 116b347689fSMing Lei static struct blk_mq_ctx *blk_mq_next_ctx(struct blk_mq_hw_ctx *hctx, 117b347689fSMing Lei struct blk_mq_ctx *ctx) 118b347689fSMing Lei { 119f31967f0SJens Axboe unsigned short idx = ctx->index_hw[hctx->type]; 120b347689fSMing Lei 121b347689fSMing Lei if (++idx == hctx->nr_ctx) 122b347689fSMing Lei idx = 0; 123b347689fSMing Lei 124b347689fSMing Lei return hctx->ctxs[idx]; 125b347689fSMing Lei } 126b347689fSMing Lei 1271f460b63SMing Lei /* 1281f460b63SMing Lei * Only SCSI implements .get_budget and .put_budget, and SCSI restarts 1291f460b63SMing Lei * its queue by itself in its completion handler, so we don't need to 1301f460b63SMing Lei * restart queue if .get_budget() returns BLK_STS_NO_RESOURCE. 1311f460b63SMing Lei */ 1321f460b63SMing Lei static void blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) 133b347689fSMing Lei { 134b347689fSMing Lei struct request_queue *q = hctx->queue; 135b347689fSMing Lei LIST_HEAD(rq_list); 136b347689fSMing Lei struct blk_mq_ctx *ctx = READ_ONCE(hctx->dispatch_from); 137b347689fSMing Lei 138b347689fSMing Lei do { 139b347689fSMing Lei struct request *rq; 140b347689fSMing Lei 141b347689fSMing Lei if (!sbitmap_any_bit_set(&hctx->ctx_map)) 142b347689fSMing Lei break; 143b347689fSMing Lei 14488022d72SMing Lei if (!blk_mq_get_dispatch_budget(hctx)) 1451f460b63SMing Lei break; 146b347689fSMing Lei 147b347689fSMing Lei rq = blk_mq_dequeue_from_ctx(hctx, ctx); 148b347689fSMing Lei if (!rq) { 149b347689fSMing Lei blk_mq_put_dispatch_budget(hctx); 150b347689fSMing Lei break; 151b347689fSMing Lei } 152b347689fSMing Lei 153b347689fSMing Lei /* 154b347689fSMing Lei * Now this rq owns the budget which has to be released 155b347689fSMing Lei * if this rq won't be queued to driver via .queue_rq() 156b347689fSMing Lei * in blk_mq_dispatch_rq_list(). 157b347689fSMing Lei */ 158b347689fSMing Lei list_add(&rq->queuelist, &rq_list); 159b347689fSMing Lei 160b347689fSMing Lei /* round robin for fair dispatch */ 161b347689fSMing Lei ctx = blk_mq_next_ctx(hctx, rq->mq_ctx); 162b347689fSMing Lei 163b347689fSMing Lei } while (blk_mq_dispatch_rq_list(q, &rq_list, true)); 164b347689fSMing Lei 165b347689fSMing Lei WRITE_ONCE(hctx->dispatch_from, ctx); 166b347689fSMing Lei } 167b347689fSMing Lei 1681f460b63SMing Lei void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) 169bd166ef1SJens Axboe { 17081380ca1SOmar Sandoval struct request_queue *q = hctx->queue; 17181380ca1SOmar Sandoval struct elevator_queue *e = q->elevator; 172f9cd4bfeSJens Axboe const bool has_sched_dispatch = e && e->type->ops.dispatch_request; 173bd166ef1SJens Axboe LIST_HEAD(rq_list); 174bd166ef1SJens Axboe 175f4560ffeSMing Lei /* RCU or SRCU read lock is needed before checking quiesced flag */ 176f4560ffeSMing Lei if (unlikely(blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q))) 1771f460b63SMing Lei return; 178bd166ef1SJens Axboe 179bd166ef1SJens Axboe hctx->run++; 180bd166ef1SJens Axboe 181bd166ef1SJens Axboe /* 182bd166ef1SJens Axboe * If we have previous entries on our dispatch list, grab them first for 183bd166ef1SJens Axboe * more fair dispatch. 184bd166ef1SJens Axboe */ 185bd166ef1SJens Axboe if (!list_empty_careful(&hctx->dispatch)) { 186bd166ef1SJens Axboe spin_lock(&hctx->lock); 187bd166ef1SJens Axboe if (!list_empty(&hctx->dispatch)) 188bd166ef1SJens Axboe list_splice_init(&hctx->dispatch, &rq_list); 189bd166ef1SJens Axboe spin_unlock(&hctx->lock); 190bd166ef1SJens Axboe } 191bd166ef1SJens Axboe 192bd166ef1SJens Axboe /* 193bd166ef1SJens Axboe * Only ask the scheduler for requests, if we didn't have residual 194bd166ef1SJens Axboe * requests from the dispatch list. This is to avoid the case where 195bd166ef1SJens Axboe * we only ever dispatch a fraction of the requests available because 196bd166ef1SJens Axboe * of low device queue depth. Once we pull requests out of the IO 197bd166ef1SJens Axboe * scheduler, we can no longer merge or sort them. So it's best to 198bd166ef1SJens Axboe * leave them there for as long as we can. Mark the hw queue as 199bd166ef1SJens Axboe * needing a restart in that case. 200caf8eb0dSMing Lei * 2015e3d02bbSMing Lei * We want to dispatch from the scheduler if there was nothing 2025e3d02bbSMing Lei * on the dispatch list or we were able to dispatch from the 2035e3d02bbSMing Lei * dispatch list. 20464765a75SJens Axboe */ 205caf8eb0dSMing Lei if (!list_empty(&rq_list)) { 206caf8eb0dSMing Lei blk_mq_sched_mark_restart_hctx(hctx); 207b347689fSMing Lei if (blk_mq_dispatch_rq_list(q, &rq_list, false)) { 208b347689fSMing Lei if (has_sched_dispatch) 2091f460b63SMing Lei blk_mq_do_dispatch_sched(hctx); 210b347689fSMing Lei else 2111f460b63SMing Lei blk_mq_do_dispatch_ctx(hctx); 212b347689fSMing Lei } 213caf8eb0dSMing Lei } else if (has_sched_dispatch) { 2141f460b63SMing Lei blk_mq_do_dispatch_sched(hctx); 2156e768717SMing Lei } else if (hctx->dispatch_busy) { 2166e768717SMing Lei /* dequeue request one by one from sw queue if queue is busy */ 2171f460b63SMing Lei blk_mq_do_dispatch_ctx(hctx); 218caf8eb0dSMing Lei } else { 219caf8eb0dSMing Lei blk_mq_flush_busy_ctxs(hctx, &rq_list); 220de148297SMing Lei blk_mq_dispatch_rq_list(q, &rq_list, false); 221c13660a0SJens Axboe } 222bd166ef1SJens Axboe } 223bd166ef1SJens Axboe 224e4d750c9SJens Axboe bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, 225e4d750c9SJens Axboe struct request **merged_request) 226bd166ef1SJens Axboe { 227bd166ef1SJens Axboe struct request *rq; 228bd166ef1SJens Axboe 22934fe7c05SChristoph Hellwig switch (elv_merge(q, &rq, bio)) { 23034fe7c05SChristoph Hellwig case ELEVATOR_BACK_MERGE: 231bd166ef1SJens Axboe if (!blk_mq_sched_allow_merge(q, rq, bio)) 232bd166ef1SJens Axboe return false; 23334fe7c05SChristoph Hellwig if (!bio_attempt_back_merge(q, rq, bio)) 23434fe7c05SChristoph Hellwig return false; 235e4d750c9SJens Axboe *merged_request = attempt_back_merge(q, rq); 236e4d750c9SJens Axboe if (!*merged_request) 23734fe7c05SChristoph Hellwig elv_merged_request(q, rq, ELEVATOR_BACK_MERGE); 238bd166ef1SJens Axboe return true; 23934fe7c05SChristoph Hellwig case ELEVATOR_FRONT_MERGE: 240bd166ef1SJens Axboe if (!blk_mq_sched_allow_merge(q, rq, bio)) 241bd166ef1SJens Axboe return false; 24234fe7c05SChristoph Hellwig if (!bio_attempt_front_merge(q, rq, bio)) 24334fe7c05SChristoph Hellwig return false; 244e4d750c9SJens Axboe *merged_request = attempt_front_merge(q, rq); 245e4d750c9SJens Axboe if (!*merged_request) 24634fe7c05SChristoph Hellwig elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE); 247bd166ef1SJens Axboe return true; 248bea99a50SKeith Busch case ELEVATOR_DISCARD_MERGE: 249bea99a50SKeith Busch return bio_attempt_discard_merge(q, rq, bio); 25034fe7c05SChristoph Hellwig default: 251bd166ef1SJens Axboe return false; 252bd166ef1SJens Axboe } 25334fe7c05SChristoph Hellwig } 254bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); 255bd166ef1SJens Axboe 2569bddeb2aSMing Lei /* 2579c558734SJens Axboe * Iterate list of requests and see if we can merge this bio with any 2589c558734SJens Axboe * of them. 2599bddeb2aSMing Lei */ 2609c558734SJens Axboe bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list, 2619c558734SJens Axboe struct bio *bio) 2629bddeb2aSMing Lei { 2639bddeb2aSMing Lei struct request *rq; 2649bddeb2aSMing Lei int checked = 8; 2659bddeb2aSMing Lei 2669c558734SJens Axboe list_for_each_entry_reverse(rq, list, queuelist) { 2679bddeb2aSMing Lei bool merged = false; 2689bddeb2aSMing Lei 2699bddeb2aSMing Lei if (!checked--) 2709bddeb2aSMing Lei break; 2719bddeb2aSMing Lei 2729bddeb2aSMing Lei if (!blk_rq_merge_ok(rq, bio)) 2739bddeb2aSMing Lei continue; 2749bddeb2aSMing Lei 2759bddeb2aSMing Lei switch (blk_try_merge(rq, bio)) { 2769bddeb2aSMing Lei case ELEVATOR_BACK_MERGE: 2779bddeb2aSMing Lei if (blk_mq_sched_allow_merge(q, rq, bio)) 2789bddeb2aSMing Lei merged = bio_attempt_back_merge(q, rq, bio); 2799bddeb2aSMing Lei break; 2809bddeb2aSMing Lei case ELEVATOR_FRONT_MERGE: 2819bddeb2aSMing Lei if (blk_mq_sched_allow_merge(q, rq, bio)) 2829bddeb2aSMing Lei merged = bio_attempt_front_merge(q, rq, bio); 2839bddeb2aSMing Lei break; 2849bddeb2aSMing Lei case ELEVATOR_DISCARD_MERGE: 2859bddeb2aSMing Lei merged = bio_attempt_discard_merge(q, rq, bio); 2869bddeb2aSMing Lei break; 2879bddeb2aSMing Lei default: 2889bddeb2aSMing Lei continue; 2899bddeb2aSMing Lei } 2909bddeb2aSMing Lei 2919bddeb2aSMing Lei return merged; 2929bddeb2aSMing Lei } 2939bddeb2aSMing Lei 2949bddeb2aSMing Lei return false; 2959bddeb2aSMing Lei } 2969c558734SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_bio_list_merge); 2979c558734SJens Axboe 2989c558734SJens Axboe /* 2999c558734SJens Axboe * Reverse check our software queue for entries that we could potentially 3009c558734SJens Axboe * merge with. Currently includes a hand-wavy stop count of 8, to not spend 3019c558734SJens Axboe * too much time checking for merges. 3029c558734SJens Axboe */ 3039c558734SJens Axboe static bool blk_mq_attempt_merge(struct request_queue *q, 3049c558734SJens Axboe struct blk_mq_ctx *ctx, struct bio *bio) 3059c558734SJens Axboe { 3069c558734SJens Axboe lockdep_assert_held(&ctx->lock); 3079c558734SJens Axboe 3089c558734SJens Axboe if (blk_mq_bio_list_merge(q, &ctx->rq_list, bio)) { 3099c558734SJens Axboe ctx->rq_merged++; 3109c558734SJens Axboe return true; 3119c558734SJens Axboe } 3129c558734SJens Axboe 3139c558734SJens Axboe return false; 3149c558734SJens Axboe } 3159bddeb2aSMing Lei 316bd166ef1SJens Axboe bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) 317bd166ef1SJens Axboe { 318bd166ef1SJens Axboe struct elevator_queue *e = q->elevator; 319bd166ef1SJens Axboe struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); 320f9afca4dSJens Axboe struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, bio->bi_opf, ctx->cpu); 3219bddeb2aSMing Lei bool ret = false; 322bd166ef1SJens Axboe 323f9cd4bfeSJens Axboe if (e && e->type->ops.bio_merge) { 324bd166ef1SJens Axboe blk_mq_put_ctx(ctx); 325f9cd4bfeSJens Axboe return e->type->ops.bio_merge(hctx, bio); 326bd166ef1SJens Axboe } 327bd166ef1SJens Axboe 328b04f50abSMing Lei if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) && 329b04f50abSMing Lei !list_empty_careful(&ctx->rq_list)) { 3309bddeb2aSMing Lei /* default per sw-queue merge */ 3319bddeb2aSMing Lei spin_lock(&ctx->lock); 3329bddeb2aSMing Lei ret = blk_mq_attempt_merge(q, ctx, bio); 3339bddeb2aSMing Lei spin_unlock(&ctx->lock); 3349bddeb2aSMing Lei } 3359bddeb2aSMing Lei 3369bddeb2aSMing Lei blk_mq_put_ctx(ctx); 3379bddeb2aSMing Lei return ret; 338bd166ef1SJens Axboe } 339bd166ef1SJens Axboe 340bd166ef1SJens Axboe bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq) 341bd166ef1SJens Axboe { 342bd166ef1SJens Axboe return rq_mergeable(rq) && elv_attempt_insert_merge(q, rq); 343bd166ef1SJens Axboe } 344bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_try_insert_merge); 345bd166ef1SJens Axboe 346bd166ef1SJens Axboe void blk_mq_sched_request_inserted(struct request *rq) 347bd166ef1SJens Axboe { 348bd166ef1SJens Axboe trace_block_rq_insert(rq->q, rq); 349bd166ef1SJens Axboe } 350bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted); 351bd166ef1SJens Axboe 3520cacba6cSOmar Sandoval static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, 353a6a252e6SMing Lei bool has_sched, 3540cacba6cSOmar Sandoval struct request *rq) 355bd166ef1SJens Axboe { 356a6a252e6SMing Lei /* dispatch flush rq directly */ 357a6a252e6SMing Lei if (rq->rq_flags & RQF_FLUSH_SEQ) { 358bd166ef1SJens Axboe spin_lock(&hctx->lock); 359bd166ef1SJens Axboe list_add(&rq->queuelist, &hctx->dispatch); 360bd166ef1SJens Axboe spin_unlock(&hctx->lock); 361bd166ef1SJens Axboe return true; 362bd166ef1SJens Axboe } 363bd166ef1SJens Axboe 364923218f6SMing Lei if (has_sched) 365a6a252e6SMing Lei rq->rq_flags |= RQF_SORTED; 366a6a252e6SMing Lei 367a6a252e6SMing Lei return false; 368a6a252e6SMing Lei } 369a6a252e6SMing Lei 370bd6737f1SJens Axboe void blk_mq_sched_insert_request(struct request *rq, bool at_head, 3719e97d295SMike Snitzer bool run_queue, bool async) 372bd6737f1SJens Axboe { 373bd6737f1SJens Axboe struct request_queue *q = rq->q; 374bd6737f1SJens Axboe struct elevator_queue *e = q->elevator; 375bd6737f1SJens Axboe struct blk_mq_ctx *ctx = rq->mq_ctx; 376ea4f995eSJens Axboe struct blk_mq_hw_ctx *hctx = rq->mq_hctx; 377bd6737f1SJens Axboe 378a6a252e6SMing Lei /* flush rq in flush machinery need to be dispatched directly */ 379a6a252e6SMing Lei if (!(rq->rq_flags & RQF_FLUSH_SEQ) && op_is_flush(rq->cmd_flags)) { 380923218f6SMing Lei blk_insert_flush(rq); 381923218f6SMing Lei goto run; 382bd6737f1SJens Axboe } 383bd6737f1SJens Axboe 384923218f6SMing Lei WARN_ON(e && (rq->tag != -1)); 385923218f6SMing Lei 386a6a252e6SMing Lei if (blk_mq_sched_bypass_insert(hctx, !!e, rq)) 3870cacba6cSOmar Sandoval goto run; 3880cacba6cSOmar Sandoval 389f9cd4bfeSJens Axboe if (e && e->type->ops.insert_requests) { 390bd6737f1SJens Axboe LIST_HEAD(list); 391bd6737f1SJens Axboe 392bd6737f1SJens Axboe list_add(&rq->queuelist, &list); 393f9cd4bfeSJens Axboe e->type->ops.insert_requests(hctx, &list, at_head); 394bd6737f1SJens Axboe } else { 395bd6737f1SJens Axboe spin_lock(&ctx->lock); 396bd6737f1SJens Axboe __blk_mq_insert_request(hctx, rq, at_head); 397bd6737f1SJens Axboe spin_unlock(&ctx->lock); 398bd6737f1SJens Axboe } 399bd6737f1SJens Axboe 4000cacba6cSOmar Sandoval run: 401bd6737f1SJens Axboe if (run_queue) 402bd6737f1SJens Axboe blk_mq_run_hw_queue(hctx, async); 403bd6737f1SJens Axboe } 404bd6737f1SJens Axboe 40567cae4c9SJens Axboe void blk_mq_sched_insert_requests(struct blk_mq_hw_ctx *hctx, 406bd6737f1SJens Axboe struct blk_mq_ctx *ctx, 407bd6737f1SJens Axboe struct list_head *list, bool run_queue_async) 408bd6737f1SJens Axboe { 409f9afca4dSJens Axboe struct elevator_queue *e; 410f9afca4dSJens Axboe 411f9afca4dSJens Axboe e = hctx->queue->elevator; 412f9cd4bfeSJens Axboe if (e && e->type->ops.insert_requests) 413f9cd4bfeSJens Axboe e->type->ops.insert_requests(hctx, list, false); 4146ce3dd6eSMing Lei else { 4156ce3dd6eSMing Lei /* 4166ce3dd6eSMing Lei * try to issue requests directly if the hw queue isn't 4176ce3dd6eSMing Lei * busy in case of 'none' scheduler, and this way may save 4186ce3dd6eSMing Lei * us one extra enqueue & dequeue to sw queue. 4196ce3dd6eSMing Lei */ 4205b7a6f12SJianchao Wang if (!hctx->dispatch_busy && !e && !run_queue_async) 4216ce3dd6eSMing Lei blk_mq_try_issue_list_directly(hctx, list); 4225b7a6f12SJianchao Wang else 423bd6737f1SJens Axboe blk_mq_insert_requests(hctx, ctx, list); 4246ce3dd6eSMing Lei } 425bd6737f1SJens Axboe 426bd6737f1SJens Axboe blk_mq_run_hw_queue(hctx, run_queue_async); 427bd6737f1SJens Axboe } 428bd6737f1SJens Axboe 429bd166ef1SJens Axboe static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, 430bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx, 431bd166ef1SJens Axboe unsigned int hctx_idx) 432bd166ef1SJens Axboe { 433bd166ef1SJens Axboe if (hctx->sched_tags) { 434bd166ef1SJens Axboe blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx); 435bd166ef1SJens Axboe blk_mq_free_rq_map(hctx->sched_tags); 436bd166ef1SJens Axboe hctx->sched_tags = NULL; 437bd166ef1SJens Axboe } 438bd166ef1SJens Axboe } 439bd166ef1SJens Axboe 4406917ff0bSOmar Sandoval static int blk_mq_sched_alloc_tags(struct request_queue *q, 4416917ff0bSOmar Sandoval struct blk_mq_hw_ctx *hctx, 4426917ff0bSOmar Sandoval unsigned int hctx_idx) 443bd166ef1SJens Axboe { 444bd166ef1SJens Axboe struct blk_mq_tag_set *set = q->tag_set; 4456917ff0bSOmar Sandoval int ret; 446bd166ef1SJens Axboe 4476917ff0bSOmar Sandoval hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests, 4486917ff0bSOmar Sandoval set->reserved_tags); 449bd166ef1SJens Axboe if (!hctx->sched_tags) 4506917ff0bSOmar Sandoval return -ENOMEM; 4516917ff0bSOmar Sandoval 4526917ff0bSOmar Sandoval ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests); 4536917ff0bSOmar Sandoval if (ret) 4546917ff0bSOmar Sandoval blk_mq_sched_free_tags(set, hctx, hctx_idx); 455bd166ef1SJens Axboe 456bd166ef1SJens Axboe return ret; 457bd166ef1SJens Axboe } 458bd166ef1SJens Axboe 45954d5329dSOmar Sandoval static void blk_mq_sched_tags_teardown(struct request_queue *q) 460bd166ef1SJens Axboe { 461bd166ef1SJens Axboe struct blk_mq_tag_set *set = q->tag_set; 462bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx; 463bd166ef1SJens Axboe int i; 464bd166ef1SJens Axboe 465bd166ef1SJens Axboe queue_for_each_hw_ctx(q, hctx, i) 466bd166ef1SJens Axboe blk_mq_sched_free_tags(set, hctx, i); 467bd166ef1SJens Axboe } 468d3484991SJens Axboe 4696917ff0bSOmar Sandoval int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) 4706917ff0bSOmar Sandoval { 4716917ff0bSOmar Sandoval struct blk_mq_hw_ctx *hctx; 472ee056f98SOmar Sandoval struct elevator_queue *eq; 4736917ff0bSOmar Sandoval unsigned int i; 4746917ff0bSOmar Sandoval int ret; 4756917ff0bSOmar Sandoval 4766917ff0bSOmar Sandoval if (!e) { 4776917ff0bSOmar Sandoval q->elevator = NULL; 47832a50fabSMing Lei q->nr_requests = q->tag_set->queue_depth; 4796917ff0bSOmar Sandoval return 0; 4806917ff0bSOmar Sandoval } 4816917ff0bSOmar Sandoval 4826917ff0bSOmar Sandoval /* 48332825c45SMing Lei * Default to double of smaller one between hw queue_depth and 128, 48432825c45SMing Lei * since we don't split into sync/async like the old code did. 48532825c45SMing Lei * Additionally, this is a per-hw queue depth. 4866917ff0bSOmar Sandoval */ 48732825c45SMing Lei q->nr_requests = 2 * min_t(unsigned int, q->tag_set->queue_depth, 48832825c45SMing Lei BLKDEV_MAX_RQ); 4896917ff0bSOmar Sandoval 4906917ff0bSOmar Sandoval queue_for_each_hw_ctx(q, hctx, i) { 4916917ff0bSOmar Sandoval ret = blk_mq_sched_alloc_tags(q, hctx, i); 4926917ff0bSOmar Sandoval if (ret) 4936917ff0bSOmar Sandoval goto err; 4946917ff0bSOmar Sandoval } 4956917ff0bSOmar Sandoval 496f9cd4bfeSJens Axboe ret = e->ops.init_sched(q, e); 4976917ff0bSOmar Sandoval if (ret) 4986917ff0bSOmar Sandoval goto err; 4996917ff0bSOmar Sandoval 500d332ce09SOmar Sandoval blk_mq_debugfs_register_sched(q); 501d332ce09SOmar Sandoval 502ee056f98SOmar Sandoval queue_for_each_hw_ctx(q, hctx, i) { 503f9cd4bfeSJens Axboe if (e->ops.init_hctx) { 504f9cd4bfeSJens Axboe ret = e->ops.init_hctx(hctx, i); 505ee056f98SOmar Sandoval if (ret) { 506ee056f98SOmar Sandoval eq = q->elevator; 507ee056f98SOmar Sandoval blk_mq_exit_sched(q, eq); 508ee056f98SOmar Sandoval kobject_put(&eq->kobj); 509ee056f98SOmar Sandoval return ret; 510ee056f98SOmar Sandoval } 511ee056f98SOmar Sandoval } 512d332ce09SOmar Sandoval blk_mq_debugfs_register_sched_hctx(q, hctx); 513ee056f98SOmar Sandoval } 514ee056f98SOmar Sandoval 5156917ff0bSOmar Sandoval return 0; 5166917ff0bSOmar Sandoval 5176917ff0bSOmar Sandoval err: 51854d5329dSOmar Sandoval blk_mq_sched_tags_teardown(q); 51954d5329dSOmar Sandoval q->elevator = NULL; 5206917ff0bSOmar Sandoval return ret; 5216917ff0bSOmar Sandoval } 5226917ff0bSOmar Sandoval 52354d5329dSOmar Sandoval void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e) 52454d5329dSOmar Sandoval { 525ee056f98SOmar Sandoval struct blk_mq_hw_ctx *hctx; 526ee056f98SOmar Sandoval unsigned int i; 527ee056f98SOmar Sandoval 528ee056f98SOmar Sandoval queue_for_each_hw_ctx(q, hctx, i) { 529d332ce09SOmar Sandoval blk_mq_debugfs_unregister_sched_hctx(hctx); 530f9cd4bfeSJens Axboe if (e->type->ops.exit_hctx && hctx->sched_data) { 531f9cd4bfeSJens Axboe e->type->ops.exit_hctx(hctx, i); 532ee056f98SOmar Sandoval hctx->sched_data = NULL; 533ee056f98SOmar Sandoval } 534ee056f98SOmar Sandoval } 535d332ce09SOmar Sandoval blk_mq_debugfs_unregister_sched(q); 536f9cd4bfeSJens Axboe if (e->type->ops.exit_sched) 537f9cd4bfeSJens Axboe e->type->ops.exit_sched(e); 53854d5329dSOmar Sandoval blk_mq_sched_tags_teardown(q); 53954d5329dSOmar Sandoval q->elevator = NULL; 54054d5329dSOmar Sandoval } 541