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" 14bd166ef1SJens Axboe #include "blk-mq-sched.h" 15bd166ef1SJens Axboe #include "blk-mq-tag.h" 16bd166ef1SJens Axboe #include "blk-wbt.h" 17bd166ef1SJens Axboe 18bd166ef1SJens Axboe void blk_mq_sched_free_hctx_data(struct request_queue *q, 19bd166ef1SJens Axboe void (*exit)(struct blk_mq_hw_ctx *)) 20bd166ef1SJens Axboe { 21bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx; 22bd166ef1SJens Axboe int i; 23bd166ef1SJens Axboe 24bd166ef1SJens Axboe queue_for_each_hw_ctx(q, hctx, i) { 25bd166ef1SJens Axboe if (exit && hctx->sched_data) 26bd166ef1SJens Axboe exit(hctx); 27bd166ef1SJens Axboe kfree(hctx->sched_data); 28bd166ef1SJens Axboe hctx->sched_data = NULL; 29bd166ef1SJens Axboe } 30bd166ef1SJens Axboe } 31bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data); 32bd166ef1SJens Axboe 33bd166ef1SJens Axboe int blk_mq_sched_init_hctx_data(struct request_queue *q, size_t size, 34bd166ef1SJens Axboe int (*init)(struct blk_mq_hw_ctx *), 35bd166ef1SJens Axboe void (*exit)(struct blk_mq_hw_ctx *)) 36bd166ef1SJens Axboe { 37bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx; 38bd166ef1SJens Axboe int ret; 39bd166ef1SJens Axboe int i; 40bd166ef1SJens Axboe 41bd166ef1SJens Axboe queue_for_each_hw_ctx(q, hctx, i) { 42bd166ef1SJens Axboe hctx->sched_data = kmalloc_node(size, GFP_KERNEL, hctx->numa_node); 43bd166ef1SJens Axboe if (!hctx->sched_data) { 44bd166ef1SJens Axboe ret = -ENOMEM; 45bd166ef1SJens Axboe goto error; 46bd166ef1SJens Axboe } 47bd166ef1SJens Axboe 48bd166ef1SJens Axboe if (init) { 49bd166ef1SJens Axboe ret = init(hctx); 50bd166ef1SJens Axboe if (ret) { 51bd166ef1SJens Axboe /* 52bd166ef1SJens Axboe * We don't want to give exit() a partially 53bd166ef1SJens Axboe * initialized sched_data. init() must clean up 54bd166ef1SJens Axboe * if it fails. 55bd166ef1SJens Axboe */ 56bd166ef1SJens Axboe kfree(hctx->sched_data); 57bd166ef1SJens Axboe hctx->sched_data = NULL; 58bd166ef1SJens Axboe goto error; 59bd166ef1SJens Axboe } 60bd166ef1SJens Axboe } 61bd166ef1SJens Axboe } 62bd166ef1SJens Axboe 63bd166ef1SJens Axboe return 0; 64bd166ef1SJens Axboe error: 65bd166ef1SJens Axboe blk_mq_sched_free_hctx_data(q, exit); 66bd166ef1SJens Axboe return ret; 67bd166ef1SJens Axboe } 68bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_init_hctx_data); 69bd166ef1SJens Axboe 70bd166ef1SJens Axboe static void __blk_mq_sched_assign_ioc(struct request_queue *q, 71f1ba8261SPaolo Valente struct request *rq, 72f1ba8261SPaolo Valente struct bio *bio, 73f1ba8261SPaolo Valente struct io_context *ioc) 74bd166ef1SJens Axboe { 75bd166ef1SJens Axboe struct io_cq *icq; 76bd166ef1SJens Axboe 77bd166ef1SJens Axboe spin_lock_irq(q->queue_lock); 78bd166ef1SJens Axboe icq = ioc_lookup_icq(ioc, q); 79bd166ef1SJens Axboe spin_unlock_irq(q->queue_lock); 80bd166ef1SJens Axboe 81bd166ef1SJens Axboe if (!icq) { 82bd166ef1SJens Axboe icq = ioc_create_icq(ioc, q, GFP_ATOMIC); 83bd166ef1SJens Axboe if (!icq) 84bd166ef1SJens Axboe return; 85bd166ef1SJens Axboe } 86bd166ef1SJens Axboe 87bd166ef1SJens Axboe rq->elv.icq = icq; 88f1ba8261SPaolo Valente if (!blk_mq_sched_get_rq_priv(q, rq, bio)) { 89bd166ef1SJens Axboe rq->rq_flags |= RQF_ELVPRIV; 90bd166ef1SJens Axboe get_io_context(icq->ioc); 91bd166ef1SJens Axboe return; 92bd166ef1SJens Axboe } 93bd166ef1SJens Axboe 94bd166ef1SJens Axboe rq->elv.icq = NULL; 95bd166ef1SJens Axboe } 96bd166ef1SJens Axboe 97bd166ef1SJens Axboe static void blk_mq_sched_assign_ioc(struct request_queue *q, 98bd166ef1SJens Axboe struct request *rq, struct bio *bio) 99bd166ef1SJens Axboe { 100bd166ef1SJens Axboe struct io_context *ioc; 101bd166ef1SJens Axboe 102bd166ef1SJens Axboe ioc = rq_ioc(bio); 103bd166ef1SJens Axboe if (ioc) 104f1ba8261SPaolo Valente __blk_mq_sched_assign_ioc(q, rq, bio, ioc); 105bd166ef1SJens Axboe } 106bd166ef1SJens Axboe 107bd166ef1SJens Axboe struct request *blk_mq_sched_get_request(struct request_queue *q, 108bd166ef1SJens Axboe struct bio *bio, 109bd166ef1SJens Axboe unsigned int op, 110bd166ef1SJens Axboe struct blk_mq_alloc_data *data) 111bd166ef1SJens Axboe { 112bd166ef1SJens Axboe struct elevator_queue *e = q->elevator; 113bd166ef1SJens Axboe struct request *rq; 114bd166ef1SJens Axboe 115bd166ef1SJens Axboe blk_queue_enter_live(q); 1166d2809d5SOmar Sandoval data->q = q; 1176d2809d5SOmar Sandoval if (likely(!data->ctx)) 1186d2809d5SOmar Sandoval data->ctx = blk_mq_get_ctx(q); 1196d2809d5SOmar Sandoval if (likely(!data->hctx)) 1206d2809d5SOmar Sandoval data->hctx = blk_mq_map_queue(q, data->ctx->cpu); 121bd166ef1SJens Axboe 122bd166ef1SJens Axboe if (e) { 123bd166ef1SJens Axboe data->flags |= BLK_MQ_REQ_INTERNAL; 124bd166ef1SJens Axboe 125bd166ef1SJens Axboe /* 126bd166ef1SJens Axboe * Flush requests are special and go directly to the 127bd166ef1SJens Axboe * dispatch list. 128bd166ef1SJens Axboe */ 129f73f44ebSChristoph Hellwig if (!op_is_flush(op) && e->type->ops.mq.get_request) { 130bd166ef1SJens Axboe rq = e->type->ops.mq.get_request(q, op, data); 131bd166ef1SJens Axboe if (rq) 132bd166ef1SJens Axboe rq->rq_flags |= RQF_QUEUED; 133bd166ef1SJens Axboe } else 134bd166ef1SJens Axboe rq = __blk_mq_alloc_request(data, op); 135bd166ef1SJens Axboe } else { 136bd166ef1SJens Axboe rq = __blk_mq_alloc_request(data, op); 137bd166ef1SJens Axboe } 138bd166ef1SJens Axboe 139bd166ef1SJens Axboe if (rq) { 140f73f44ebSChristoph Hellwig if (!op_is_flush(op)) { 141bd166ef1SJens Axboe rq->elv.icq = NULL; 142bd166ef1SJens Axboe if (e && e->type->icq_cache) 143bd166ef1SJens Axboe blk_mq_sched_assign_ioc(q, rq, bio); 144bd166ef1SJens Axboe } 145bd166ef1SJens Axboe data->hctx->queued++; 146bd166ef1SJens Axboe return rq; 147bd166ef1SJens Axboe } 148bd166ef1SJens Axboe 149bd166ef1SJens Axboe blk_queue_exit(q); 150bd166ef1SJens Axboe return NULL; 151bd166ef1SJens Axboe } 152bd166ef1SJens Axboe 153bd166ef1SJens Axboe void blk_mq_sched_put_request(struct request *rq) 154bd166ef1SJens Axboe { 155bd166ef1SJens Axboe struct request_queue *q = rq->q; 156bd166ef1SJens Axboe struct elevator_queue *e = q->elevator; 157bd166ef1SJens Axboe 158bd166ef1SJens Axboe if (rq->rq_flags & RQF_ELVPRIV) { 159bd166ef1SJens Axboe blk_mq_sched_put_rq_priv(rq->q, rq); 160bd166ef1SJens Axboe if (rq->elv.icq) { 161bd166ef1SJens Axboe put_io_context(rq->elv.icq->ioc); 162bd166ef1SJens Axboe rq->elv.icq = NULL; 163bd166ef1SJens Axboe } 164bd166ef1SJens Axboe } 165bd166ef1SJens Axboe 166bd166ef1SJens Axboe if ((rq->rq_flags & RQF_QUEUED) && e && e->type->ops.mq.put_request) 167bd166ef1SJens Axboe e->type->ops.mq.put_request(rq); 168bd166ef1SJens Axboe else 169bd166ef1SJens Axboe blk_mq_finish_request(rq); 170bd166ef1SJens Axboe } 171bd166ef1SJens Axboe 172bd166ef1SJens Axboe void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) 173bd166ef1SJens Axboe { 17481380ca1SOmar Sandoval struct request_queue *q = hctx->queue; 17581380ca1SOmar Sandoval struct elevator_queue *e = q->elevator; 17664765a75SJens Axboe const bool has_sched_dispatch = e && e->type->ops.mq.dispatch_request; 17764765a75SJens Axboe bool did_work = false; 178bd166ef1SJens Axboe LIST_HEAD(rq_list); 179bd166ef1SJens Axboe 180bd166ef1SJens Axboe if (unlikely(blk_mq_hctx_stopped(hctx))) 181bd166ef1SJens Axboe return; 182bd166ef1SJens Axboe 183bd166ef1SJens Axboe hctx->run++; 184bd166ef1SJens Axboe 185bd166ef1SJens Axboe /* 186bd166ef1SJens Axboe * If we have previous entries on our dispatch list, grab them first for 187bd166ef1SJens Axboe * more fair dispatch. 188bd166ef1SJens Axboe */ 189bd166ef1SJens Axboe if (!list_empty_careful(&hctx->dispatch)) { 190bd166ef1SJens Axboe spin_lock(&hctx->lock); 191bd166ef1SJens Axboe if (!list_empty(&hctx->dispatch)) 192bd166ef1SJens Axboe list_splice_init(&hctx->dispatch, &rq_list); 193bd166ef1SJens Axboe spin_unlock(&hctx->lock); 194bd166ef1SJens Axboe } 195bd166ef1SJens Axboe 196bd166ef1SJens Axboe /* 197bd166ef1SJens Axboe * Only ask the scheduler for requests, if we didn't have residual 198bd166ef1SJens Axboe * requests from the dispatch list. This is to avoid the case where 199bd166ef1SJens Axboe * we only ever dispatch a fraction of the requests available because 200bd166ef1SJens Axboe * of low device queue depth. Once we pull requests out of the IO 201bd166ef1SJens Axboe * scheduler, we can no longer merge or sort them. So it's best to 202bd166ef1SJens Axboe * leave them there for as long as we can. Mark the hw queue as 203bd166ef1SJens Axboe * needing a restart in that case. 204bd166ef1SJens Axboe */ 205c13660a0SJens Axboe if (!list_empty(&rq_list)) { 206d38d3515SOmar Sandoval blk_mq_sched_mark_restart_hctx(hctx); 20781380ca1SOmar Sandoval did_work = blk_mq_dispatch_rq_list(q, &rq_list); 20864765a75SJens Axboe } else if (!has_sched_dispatch) { 209c13660a0SJens Axboe blk_mq_flush_busy_ctxs(hctx, &rq_list); 21081380ca1SOmar Sandoval blk_mq_dispatch_rq_list(q, &rq_list); 21164765a75SJens Axboe } 21264765a75SJens Axboe 21364765a75SJens Axboe /* 21464765a75SJens Axboe * We want to dispatch from the scheduler if we had no work left 21564765a75SJens Axboe * on the dispatch list, OR if we did have work but weren't able 21664765a75SJens Axboe * to make progress. 21764765a75SJens Axboe */ 21864765a75SJens Axboe if (!did_work && has_sched_dispatch) { 219c13660a0SJens Axboe do { 220c13660a0SJens Axboe struct request *rq; 221c13660a0SJens Axboe 222c13660a0SJens Axboe rq = e->type->ops.mq.dispatch_request(hctx); 223c13660a0SJens Axboe if (!rq) 224c13660a0SJens Axboe break; 225c13660a0SJens Axboe list_add(&rq->queuelist, &rq_list); 22681380ca1SOmar Sandoval } while (blk_mq_dispatch_rq_list(q, &rq_list)); 227c13660a0SJens Axboe } 228bd166ef1SJens Axboe } 229bd166ef1SJens Axboe 230bd166ef1SJens Axboe void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, 231bd166ef1SJens Axboe struct list_head *rq_list, 232bd166ef1SJens Axboe struct request *(*get_rq)(struct blk_mq_hw_ctx *)) 233bd166ef1SJens Axboe { 234bd166ef1SJens Axboe do { 235bd166ef1SJens Axboe struct request *rq; 236bd166ef1SJens Axboe 237bd166ef1SJens Axboe rq = get_rq(hctx); 238bd166ef1SJens Axboe if (!rq) 239bd166ef1SJens Axboe break; 240bd166ef1SJens Axboe 241bd166ef1SJens Axboe list_add_tail(&rq->queuelist, rq_list); 242bd166ef1SJens Axboe } while (1); 243bd166ef1SJens Axboe } 244bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_move_to_dispatch); 245bd166ef1SJens Axboe 246e4d750c9SJens Axboe bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, 247e4d750c9SJens Axboe struct request **merged_request) 248bd166ef1SJens Axboe { 249bd166ef1SJens Axboe struct request *rq; 250bd166ef1SJens Axboe 25134fe7c05SChristoph Hellwig switch (elv_merge(q, &rq, bio)) { 25234fe7c05SChristoph Hellwig case ELEVATOR_BACK_MERGE: 253bd166ef1SJens Axboe if (!blk_mq_sched_allow_merge(q, rq, bio)) 254bd166ef1SJens Axboe return false; 25534fe7c05SChristoph Hellwig if (!bio_attempt_back_merge(q, rq, bio)) 25634fe7c05SChristoph Hellwig return false; 257e4d750c9SJens Axboe *merged_request = attempt_back_merge(q, rq); 258e4d750c9SJens Axboe if (!*merged_request) 25934fe7c05SChristoph Hellwig elv_merged_request(q, rq, ELEVATOR_BACK_MERGE); 260bd166ef1SJens Axboe return true; 26134fe7c05SChristoph Hellwig case ELEVATOR_FRONT_MERGE: 262bd166ef1SJens Axboe if (!blk_mq_sched_allow_merge(q, rq, bio)) 263bd166ef1SJens Axboe return false; 26434fe7c05SChristoph Hellwig if (!bio_attempt_front_merge(q, rq, bio)) 26534fe7c05SChristoph Hellwig return false; 266e4d750c9SJens Axboe *merged_request = attempt_front_merge(q, rq); 267e4d750c9SJens Axboe if (!*merged_request) 26834fe7c05SChristoph Hellwig elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE); 269bd166ef1SJens Axboe return true; 27034fe7c05SChristoph Hellwig default: 271bd166ef1SJens Axboe return false; 272bd166ef1SJens Axboe } 27334fe7c05SChristoph Hellwig } 274bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); 275bd166ef1SJens Axboe 276bd166ef1SJens Axboe bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) 277bd166ef1SJens Axboe { 278bd166ef1SJens Axboe struct elevator_queue *e = q->elevator; 279bd166ef1SJens Axboe 280bd166ef1SJens Axboe if (e->type->ops.mq.bio_merge) { 281bd166ef1SJens Axboe struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); 282bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); 283bd166ef1SJens Axboe 284bd166ef1SJens Axboe blk_mq_put_ctx(ctx); 285bd166ef1SJens Axboe return e->type->ops.mq.bio_merge(hctx, bio); 286bd166ef1SJens Axboe } 287bd166ef1SJens Axboe 288bd166ef1SJens Axboe return false; 289bd166ef1SJens Axboe } 290bd166ef1SJens Axboe 291bd166ef1SJens Axboe bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq) 292bd166ef1SJens Axboe { 293bd166ef1SJens Axboe return rq_mergeable(rq) && elv_attempt_insert_merge(q, rq); 294bd166ef1SJens Axboe } 295bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_try_insert_merge); 296bd166ef1SJens Axboe 297bd166ef1SJens Axboe void blk_mq_sched_request_inserted(struct request *rq) 298bd166ef1SJens Axboe { 299bd166ef1SJens Axboe trace_block_rq_insert(rq->q, rq); 300bd166ef1SJens Axboe } 301bd166ef1SJens Axboe EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted); 302bd166ef1SJens Axboe 3030cacba6cSOmar Sandoval static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, 3040cacba6cSOmar Sandoval struct request *rq) 305bd166ef1SJens Axboe { 306bd166ef1SJens Axboe if (rq->tag == -1) { 307bd166ef1SJens Axboe rq->rq_flags |= RQF_SORTED; 308bd166ef1SJens Axboe return false; 309bd166ef1SJens Axboe } 310bd166ef1SJens Axboe 311bd166ef1SJens Axboe /* 312bd166ef1SJens Axboe * If we already have a real request tag, send directly to 313bd166ef1SJens Axboe * the dispatch list. 314bd166ef1SJens Axboe */ 315bd166ef1SJens Axboe spin_lock(&hctx->lock); 316bd166ef1SJens Axboe list_add(&rq->queuelist, &hctx->dispatch); 317bd166ef1SJens Axboe spin_unlock(&hctx->lock); 318bd166ef1SJens Axboe return true; 319bd166ef1SJens Axboe } 320bd166ef1SJens Axboe 3216d8c6c0fSBart Van Assche static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx) 32250e1dab8SJens Axboe { 32350e1dab8SJens Axboe if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { 32450e1dab8SJens Axboe clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); 3256d8c6c0fSBart Van Assche if (blk_mq_hctx_has_pending(hctx)) { 32650e1dab8SJens Axboe blk_mq_run_hw_queue(hctx, true); 3276d8c6c0fSBart Van Assche return true; 32850e1dab8SJens Axboe } 32950e1dab8SJens Axboe } 3306d8c6c0fSBart Van Assche return false; 3316d8c6c0fSBart Van Assche } 33250e1dab8SJens Axboe 3336d8c6c0fSBart Van Assche /** 3346d8c6c0fSBart Van Assche * list_for_each_entry_rcu_rr - iterate in a round-robin fashion over rcu list 3356d8c6c0fSBart Van Assche * @pos: loop cursor. 3366d8c6c0fSBart Van Assche * @skip: the list element that will not be examined. Iteration starts at 3376d8c6c0fSBart Van Assche * @skip->next. 3386d8c6c0fSBart Van Assche * @head: head of the list to examine. This list must have at least one 3396d8c6c0fSBart Van Assche * element, namely @skip. 3406d8c6c0fSBart Van Assche * @member: name of the list_head structure within typeof(*pos). 3416d8c6c0fSBart Van Assche */ 3426d8c6c0fSBart Van Assche #define list_for_each_entry_rcu_rr(pos, skip, head, member) \ 3436d8c6c0fSBart Van Assche for ((pos) = (skip); \ 3446d8c6c0fSBart Van Assche (pos = (pos)->member.next != (head) ? list_entry_rcu( \ 3456d8c6c0fSBart Van Assche (pos)->member.next, typeof(*pos), member) : \ 3466d8c6c0fSBart Van Assche list_entry_rcu((pos)->member.next->next, typeof(*pos), member)), \ 3476d8c6c0fSBart Van Assche (pos) != (skip); ) 3486d8c6c0fSBart Van Assche 3496d8c6c0fSBart Van Assche /* 3506d8c6c0fSBart Van Assche * Called after a driver tag has been freed to check whether a hctx needs to 3516d8c6c0fSBart Van Assche * be restarted. Restarts @hctx if its tag set is not shared. Restarts hardware 3526d8c6c0fSBart Van Assche * queues in a round-robin fashion if the tag set of @hctx is shared with other 3536d8c6c0fSBart Van Assche * hardware queues. 3546d8c6c0fSBart Van Assche */ 3556d8c6c0fSBart Van Assche void blk_mq_sched_restart(struct blk_mq_hw_ctx *const hctx) 35650e1dab8SJens Axboe { 3576d8c6c0fSBart Van Assche struct blk_mq_tags *const tags = hctx->tags; 3586d8c6c0fSBart Van Assche struct blk_mq_tag_set *const set = hctx->queue->tag_set; 3596d8c6c0fSBart Van Assche struct request_queue *const queue = hctx->queue, *q; 3606d8c6c0fSBart Van Assche struct blk_mq_hw_ctx *hctx2; 3616d8c6c0fSBart Van Assche unsigned int i, j; 36250e1dab8SJens Axboe 3636d8c6c0fSBart Van Assche if (set->flags & BLK_MQ_F_TAG_SHARED) { 3646d8c6c0fSBart Van Assche rcu_read_lock(); 3656d8c6c0fSBart Van Assche list_for_each_entry_rcu_rr(q, queue, &set->tag_list, 3666d8c6c0fSBart Van Assche tag_set_list) { 3676d8c6c0fSBart Van Assche queue_for_each_hw_ctx(q, hctx2, i) 3686d8c6c0fSBart Van Assche if (hctx2->tags == tags && 3696d8c6c0fSBart Van Assche blk_mq_sched_restart_hctx(hctx2)) 3706d8c6c0fSBart Van Assche goto done; 37150e1dab8SJens Axboe } 3726d8c6c0fSBart Van Assche j = hctx->queue_num + 1; 3736d8c6c0fSBart Van Assche for (i = 0; i < queue->nr_hw_queues; i++, j++) { 3746d8c6c0fSBart Van Assche if (j == queue->nr_hw_queues) 3756d8c6c0fSBart Van Assche j = 0; 3766d8c6c0fSBart Van Assche hctx2 = queue->queue_hw_ctx[j]; 3776d8c6c0fSBart Van Assche if (hctx2->tags == tags && 3786d8c6c0fSBart Van Assche blk_mq_sched_restart_hctx(hctx2)) 3796d8c6c0fSBart Van Assche break; 3806d8c6c0fSBart Van Assche } 3816d8c6c0fSBart Van Assche done: 3826d8c6c0fSBart Van Assche rcu_read_unlock(); 383d38d3515SOmar Sandoval } else { 384d38d3515SOmar Sandoval blk_mq_sched_restart_hctx(hctx); 385d38d3515SOmar Sandoval } 38650e1dab8SJens Axboe } 38750e1dab8SJens Axboe 388bd6737f1SJens Axboe /* 389bd6737f1SJens Axboe * Add flush/fua to the queue. If we fail getting a driver tag, then 390bd6737f1SJens Axboe * punt to the requeue list. Requeue will re-invoke us from a context 391bd6737f1SJens Axboe * that's safe to block from. 392bd6737f1SJens Axboe */ 393bd6737f1SJens Axboe static void blk_mq_sched_insert_flush(struct blk_mq_hw_ctx *hctx, 394bd6737f1SJens Axboe struct request *rq, bool can_block) 395bd6737f1SJens Axboe { 396bd6737f1SJens Axboe if (blk_mq_get_driver_tag(rq, &hctx, can_block)) { 397bd6737f1SJens Axboe blk_insert_flush(rq); 398bd6737f1SJens Axboe blk_mq_run_hw_queue(hctx, true); 399bd6737f1SJens Axboe } else 400c7a571b4SJens Axboe blk_mq_add_to_requeue_list(rq, false, true); 401bd6737f1SJens Axboe } 402bd6737f1SJens Axboe 403bd6737f1SJens Axboe void blk_mq_sched_insert_request(struct request *rq, bool at_head, 404bd6737f1SJens Axboe bool run_queue, bool async, bool can_block) 405bd6737f1SJens Axboe { 406bd6737f1SJens Axboe struct request_queue *q = rq->q; 407bd6737f1SJens Axboe struct elevator_queue *e = q->elevator; 408bd6737f1SJens Axboe struct blk_mq_ctx *ctx = rq->mq_ctx; 409bd6737f1SJens Axboe struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); 410bd6737f1SJens Axboe 411f3a8ab7dSJens Axboe if (rq->tag == -1 && op_is_flush(rq->cmd_flags)) { 412bd6737f1SJens Axboe blk_mq_sched_insert_flush(hctx, rq, can_block); 413bd6737f1SJens Axboe return; 414bd6737f1SJens Axboe } 415bd6737f1SJens Axboe 4160cacba6cSOmar Sandoval if (e && blk_mq_sched_bypass_insert(hctx, rq)) 4170cacba6cSOmar Sandoval goto run; 4180cacba6cSOmar Sandoval 419bd6737f1SJens Axboe if (e && e->type->ops.mq.insert_requests) { 420bd6737f1SJens Axboe LIST_HEAD(list); 421bd6737f1SJens Axboe 422bd6737f1SJens Axboe list_add(&rq->queuelist, &list); 423bd6737f1SJens Axboe e->type->ops.mq.insert_requests(hctx, &list, at_head); 424bd6737f1SJens Axboe } else { 425bd6737f1SJens Axboe spin_lock(&ctx->lock); 426bd6737f1SJens Axboe __blk_mq_insert_request(hctx, rq, at_head); 427bd6737f1SJens Axboe spin_unlock(&ctx->lock); 428bd6737f1SJens Axboe } 429bd6737f1SJens Axboe 4300cacba6cSOmar Sandoval run: 431bd6737f1SJens Axboe if (run_queue) 432bd6737f1SJens Axboe blk_mq_run_hw_queue(hctx, async); 433bd6737f1SJens Axboe } 434bd6737f1SJens Axboe 435bd6737f1SJens Axboe void blk_mq_sched_insert_requests(struct request_queue *q, 436bd6737f1SJens Axboe struct blk_mq_ctx *ctx, 437bd6737f1SJens Axboe struct list_head *list, bool run_queue_async) 438bd6737f1SJens Axboe { 439bd6737f1SJens Axboe struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); 440bd6737f1SJens Axboe struct elevator_queue *e = hctx->queue->elevator; 441bd6737f1SJens Axboe 4420cacba6cSOmar Sandoval if (e) { 4430cacba6cSOmar Sandoval struct request *rq, *next; 4440cacba6cSOmar Sandoval 4450cacba6cSOmar Sandoval /* 4460cacba6cSOmar Sandoval * We bypass requests that already have a driver tag assigned, 4470cacba6cSOmar Sandoval * which should only be flushes. Flushes are only ever inserted 4480cacba6cSOmar Sandoval * as single requests, so we shouldn't ever hit the 4490cacba6cSOmar Sandoval * WARN_ON_ONCE() below (but let's handle it just in case). 4500cacba6cSOmar Sandoval */ 4510cacba6cSOmar Sandoval list_for_each_entry_safe(rq, next, list, queuelist) { 4520cacba6cSOmar Sandoval if (WARN_ON_ONCE(rq->tag != -1)) { 4530cacba6cSOmar Sandoval list_del_init(&rq->queuelist); 4540cacba6cSOmar Sandoval blk_mq_sched_bypass_insert(hctx, rq); 4550cacba6cSOmar Sandoval } 4560cacba6cSOmar Sandoval } 4570cacba6cSOmar Sandoval } 4580cacba6cSOmar Sandoval 459bd6737f1SJens Axboe if (e && e->type->ops.mq.insert_requests) 460bd6737f1SJens Axboe e->type->ops.mq.insert_requests(hctx, list, false); 461bd6737f1SJens Axboe else 462bd6737f1SJens Axboe blk_mq_insert_requests(hctx, ctx, list); 463bd6737f1SJens Axboe 464bd6737f1SJens Axboe blk_mq_run_hw_queue(hctx, run_queue_async); 465bd6737f1SJens Axboe } 466bd6737f1SJens Axboe 467bd166ef1SJens Axboe static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, 468bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx, 469bd166ef1SJens Axboe unsigned int hctx_idx) 470bd166ef1SJens Axboe { 471bd166ef1SJens Axboe if (hctx->sched_tags) { 472bd166ef1SJens Axboe blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx); 473bd166ef1SJens Axboe blk_mq_free_rq_map(hctx->sched_tags); 474bd166ef1SJens Axboe hctx->sched_tags = NULL; 475bd166ef1SJens Axboe } 476bd166ef1SJens Axboe } 477bd166ef1SJens Axboe 4786917ff0bSOmar Sandoval static int blk_mq_sched_alloc_tags(struct request_queue *q, 4796917ff0bSOmar Sandoval struct blk_mq_hw_ctx *hctx, 4806917ff0bSOmar Sandoval unsigned int hctx_idx) 481bd166ef1SJens Axboe { 482bd166ef1SJens Axboe struct blk_mq_tag_set *set = q->tag_set; 4836917ff0bSOmar Sandoval int ret; 484bd166ef1SJens Axboe 4856917ff0bSOmar Sandoval hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests, 4866917ff0bSOmar Sandoval set->reserved_tags); 487bd166ef1SJens Axboe if (!hctx->sched_tags) 4886917ff0bSOmar Sandoval return -ENOMEM; 4896917ff0bSOmar Sandoval 4906917ff0bSOmar Sandoval ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests); 4916917ff0bSOmar Sandoval if (ret) 4926917ff0bSOmar Sandoval blk_mq_sched_free_tags(set, hctx, hctx_idx); 493bd166ef1SJens Axboe 494bd166ef1SJens Axboe return ret; 495bd166ef1SJens Axboe } 496bd166ef1SJens Axboe 49754d5329dSOmar Sandoval static void blk_mq_sched_tags_teardown(struct request_queue *q) 498bd166ef1SJens Axboe { 499bd166ef1SJens Axboe struct blk_mq_tag_set *set = q->tag_set; 500bd166ef1SJens Axboe struct blk_mq_hw_ctx *hctx; 501bd166ef1SJens Axboe int i; 502bd166ef1SJens Axboe 503bd166ef1SJens Axboe queue_for_each_hw_ctx(q, hctx, i) 504bd166ef1SJens Axboe blk_mq_sched_free_tags(set, hctx, i); 505bd166ef1SJens Axboe } 506d3484991SJens Axboe 50793252632SOmar Sandoval int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, 50893252632SOmar Sandoval unsigned int hctx_idx) 50993252632SOmar Sandoval { 51093252632SOmar Sandoval struct elevator_queue *e = q->elevator; 51193252632SOmar Sandoval 51293252632SOmar Sandoval if (!e) 51393252632SOmar Sandoval return 0; 51493252632SOmar Sandoval 51593252632SOmar Sandoval return blk_mq_sched_alloc_tags(q, hctx, hctx_idx); 51693252632SOmar Sandoval } 51793252632SOmar Sandoval 51893252632SOmar Sandoval void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, 51993252632SOmar Sandoval unsigned int hctx_idx) 52093252632SOmar Sandoval { 52193252632SOmar Sandoval struct elevator_queue *e = q->elevator; 52293252632SOmar Sandoval 52393252632SOmar Sandoval if (!e) 52493252632SOmar Sandoval return; 52593252632SOmar Sandoval 52693252632SOmar Sandoval blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx); 52793252632SOmar Sandoval } 52893252632SOmar Sandoval 5296917ff0bSOmar Sandoval int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) 5306917ff0bSOmar Sandoval { 5316917ff0bSOmar Sandoval struct blk_mq_hw_ctx *hctx; 5326917ff0bSOmar Sandoval unsigned int i; 5336917ff0bSOmar Sandoval int ret; 5346917ff0bSOmar Sandoval 5356917ff0bSOmar Sandoval if (!e) { 5366917ff0bSOmar Sandoval q->elevator = NULL; 5376917ff0bSOmar Sandoval return 0; 5386917ff0bSOmar Sandoval } 5396917ff0bSOmar Sandoval 5406917ff0bSOmar Sandoval /* 5416917ff0bSOmar Sandoval * Default to 256, since we don't split into sync/async like the 5426917ff0bSOmar Sandoval * old code did. Additionally, this is a per-hw queue depth. 5436917ff0bSOmar Sandoval */ 5446917ff0bSOmar Sandoval q->nr_requests = 2 * BLKDEV_MAX_RQ; 5456917ff0bSOmar Sandoval 5466917ff0bSOmar Sandoval queue_for_each_hw_ctx(q, hctx, i) { 5476917ff0bSOmar Sandoval ret = blk_mq_sched_alloc_tags(q, hctx, i); 5486917ff0bSOmar Sandoval if (ret) 5496917ff0bSOmar Sandoval goto err; 5506917ff0bSOmar Sandoval } 5516917ff0bSOmar Sandoval 5526917ff0bSOmar Sandoval ret = e->ops.mq.init_sched(q, e); 5536917ff0bSOmar Sandoval if (ret) 5546917ff0bSOmar Sandoval goto err; 5556917ff0bSOmar Sandoval 5566917ff0bSOmar Sandoval return 0; 5576917ff0bSOmar Sandoval 5586917ff0bSOmar Sandoval err: 55954d5329dSOmar Sandoval blk_mq_sched_tags_teardown(q); 56054d5329dSOmar Sandoval q->elevator = NULL; 5616917ff0bSOmar Sandoval return ret; 5626917ff0bSOmar Sandoval } 5636917ff0bSOmar Sandoval 56454d5329dSOmar Sandoval void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e) 56554d5329dSOmar Sandoval { 56654d5329dSOmar Sandoval if (e->type->ops.mq.exit_sched) 56754d5329dSOmar Sandoval e->type->ops.mq.exit_sched(e); 56854d5329dSOmar Sandoval blk_mq_sched_tags_teardown(q); 56954d5329dSOmar Sandoval q->elevator = NULL; 57054d5329dSOmar Sandoval } 57154d5329dSOmar Sandoval 572d3484991SJens Axboe int blk_mq_sched_init(struct request_queue *q) 573d3484991SJens Axboe { 574d3484991SJens Axboe int ret; 575d3484991SJens Axboe 576d3484991SJens Axboe mutex_lock(&q->sysfs_lock); 577d3484991SJens Axboe ret = elevator_init(q, NULL); 578d3484991SJens Axboe mutex_unlock(&q->sysfs_lock); 579d3484991SJens Axboe 580d3484991SJens Axboe return ret; 581d3484991SJens Axboe } 582