diff options
Diffstat (limited to '')
-rw-r--r-- | block/blk-mq.c | 263 |
1 files changed, 124 insertions, 139 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 6041e1749..32afb87ef 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -21,7 +21,6 @@ #include <linux/llist.h> #include <linux/cpu.h> #include <linux/cache.h> -#include <linux/sched/sysctl.h> #include <linux/sched/topology.h> #include <linux/sched/signal.h> #include <linux/delay.h> @@ -40,7 +39,6 @@ #include "blk-stat.h" #include "blk-mq-sched.h" #include "blk-rq-qos.h" -#include "blk-ioprio.h" static DEFINE_PER_CPU(struct llist_head, blk_cpu_done); static DEFINE_PER_CPU(call_single_data_t, blk_cpu_csd); @@ -323,7 +321,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq) RB_CLEAR_NODE(&rq->rb_node); rq->tag = BLK_MQ_NO_TAG; rq->internal_tag = BLK_MQ_NO_TAG; - rq->start_time_ns = ktime_get_ns(); + rq->start_time_ns = blk_time_get_ns(); rq->part = NULL; blk_crypto_rq_set_defaults(rq); } @@ -333,7 +331,7 @@ EXPORT_SYMBOL(blk_rq_init); static inline void blk_mq_rq_time_init(struct request *rq, u64 alloc_time_ns) { if (blk_mq_need_time_stamp(rq)) - rq->start_time_ns = ktime_get_ns(); + rq->start_time_ns = blk_time_get_ns(); else rq->start_time_ns = 0; @@ -426,6 +424,8 @@ __blk_mq_alloc_requests_batch(struct blk_mq_alloc_data *data) rq_list_add(data->cached_rq, rq); nr++; } + if (!(data->rq_flags & RQF_SCHED_TAGS)) + blk_mq_add_active_requests(data->hctx, nr); /* caller already holds a reference, add for remainder */ percpu_ref_get_many(&data->q->q_usage_counter, nr - 1); data->nr_tags -= nr; @@ -442,7 +442,7 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) /* alloc_time includes depth and tag waits */ if (blk_queue_rq_alloc_time(q)) - alloc_time_ns = ktime_get_ns(); + alloc_time_ns = blk_time_get_ns(); if (data->cmd_flags & REQ_NOWAIT) data->flags |= BLK_MQ_REQ_NOWAIT; @@ -510,6 +510,8 @@ retry: goto retry; } + if (!(data->rq_flags & RQF_SCHED_TAGS)) + blk_mq_inc_active_requests(data->hctx); rq = blk_mq_rq_ctx_init(data, blk_mq_tags_from_data(data), tag); blk_mq_rq_time_init(rq, alloc_time_ns); return rq; @@ -625,7 +627,7 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, /* alloc_time includes depth and tag waits */ if (blk_queue_rq_alloc_time(q)) - alloc_time_ns = ktime_get_ns(); + alloc_time_ns = blk_time_get_ns(); /* * If the tag allocator sleeps we could get an allocation for a @@ -669,6 +671,8 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, tag = blk_mq_get_tag(&data); if (tag == BLK_MQ_NO_TAG) goto out_queue_exit; + if (!(data.rq_flags & RQF_SCHED_TAGS)) + blk_mq_inc_active_requests(data.hctx); rq = blk_mq_rq_ctx_init(&data, blk_mq_tags_from_data(&data), tag); blk_mq_rq_time_init(rq, alloc_time_ns); rq->__data_len = 0; @@ -708,11 +712,10 @@ static void __blk_mq_free_request(struct request *rq) blk_pm_mark_last_busy(rq); rq->mq_hctx = NULL; - if (rq->rq_flags & RQF_MQ_INFLIGHT) - __blk_mq_dec_active_requests(hctx); - - if (rq->tag != BLK_MQ_NO_TAG) + if (rq->tag != BLK_MQ_NO_TAG) { + blk_mq_dec_active_requests(hctx); blk_mq_put_tag(hctx->tags, ctx, rq->tag); + } if (sched_tag != BLK_MQ_NO_TAG) blk_mq_put_tag(hctx->sched_tags, ctx, sched_tag); blk_mq_sched_restart(hctx); @@ -1032,7 +1035,7 @@ static inline void __blk_mq_end_request_acct(struct request *rq, u64 now) inline void __blk_mq_end_request(struct request *rq, blk_status_t error) { if (blk_mq_need_time_stamp(rq)) - __blk_mq_end_request_acct(rq, ktime_get_ns()); + __blk_mq_end_request_acct(rq, blk_time_get_ns()); blk_mq_finish_request(rq); @@ -1061,12 +1064,7 @@ static inline void blk_mq_flush_tag_batch(struct blk_mq_hw_ctx *hctx, { struct request_queue *q = hctx->queue; - /* - * All requests should have been marked as RQF_MQ_INFLIGHT, so - * update hctx->nr_active in batch - */ - if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) - __blk_mq_sub_active_requests(hctx, nr_tags); + blk_mq_sub_active_requests(hctx, nr_tags); blk_mq_put_tags(hctx->tags, tag_array, nr_tags); percpu_ref_put_many(&q->q_usage_counter, nr_tags); @@ -1080,7 +1078,7 @@ void blk_mq_end_request_batch(struct io_comp_batch *iob) u64 now = 0; if (iob->need_ts) - now = ktime_get_ns(); + now = blk_time_get_ns(); while ((rq = rq_list_pop(&iob->req_list)) != NULL) { prefetch(rq->bio); @@ -1163,10 +1161,11 @@ static inline bool blk_mq_complete_need_ipi(struct request *rq) if (force_irqthreads()) return false; - /* same CPU or cache domain? Complete locally */ + /* same CPU or cache domain and capacity? Complete locally */ if (cpu == rq->mq_ctx->cpu || (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags) && - cpus_share_cache(cpu, rq->mq_ctx->cpu))) + cpus_share_cache(cpu, rq->mq_ctx->cpu) && + cpus_equal_capacity(cpu, rq->mq_ctx->cpu))) return false; /* don't try to IPI to an offline CPU */ @@ -1248,8 +1247,9 @@ void blk_mq_start_request(struct request *rq) trace_block_rq_issue(rq); - if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { - rq->io_start_time_ns = ktime_get_ns(); + if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags) && + !blk_rq_is_passthrough(rq)) { + rq->io_start_time_ns = blk_time_get_ns(); rq->stats_sectors = blk_rq_sectors(rq); rq->rq_flags |= RQF_STATS; rq_qos_issue(q, rq); @@ -1259,6 +1259,7 @@ void blk_mq_start_request(struct request *rq) blk_add_timer(rq); WRITE_ONCE(rq->state, MQ_RQ_IN_FLIGHT); + rq->mq_hctx->tags->rqs[rq->tag] = rq; #ifdef CONFIG_BLK_DEV_INTEGRITY if (blk_integrity_rq(rq) && req_op(rq) == REQ_OP_WRITE) @@ -1403,22 +1404,10 @@ blk_status_t blk_execute_rq(struct request *rq, bool at_head) blk_mq_insert_request(rq, at_head ? BLK_MQ_INSERT_AT_HEAD : 0); blk_mq_run_hw_queue(hctx, false); - if (blk_rq_is_poll(rq)) { + if (blk_rq_is_poll(rq)) blk_rq_poll_completion(rq, &wait.done); - } else { - /* - * Prevent hang_check timer from firing at us during very long - * I/O - */ - unsigned long hang_check = sysctl_hung_task_timeout_secs; - - if (hang_check) - while (!wait_for_completion_io_timeout(&wait.done, - hang_check * (HZ/2))) - ; - else - wait_for_completion_io(&wait.done); - } + else + blk_wait_io(&wait.done); return wait.ret; } @@ -1760,7 +1749,7 @@ struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, return data.rq; } -static bool __blk_mq_alloc_driver_tag(struct request *rq) +bool __blk_mq_alloc_driver_tag(struct request *rq) { struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags; unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags; @@ -1781,20 +1770,7 @@ static bool __blk_mq_alloc_driver_tag(struct request *rq) return false; rq->tag = tag + tag_offset; - return true; -} - -bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq) -{ - if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq)) - return false; - - if ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) && - !(rq->rq_flags & RQF_MQ_INFLIGHT)) { - rq->rq_flags |= RQF_MQ_INFLIGHT; - __blk_mq_inc_active_requests(hctx); - } - hctx->tags->rqs[rq->tag] = rq; + blk_mq_inc_active_requests(rq->mq_hctx); return true; } @@ -1871,6 +1847,22 @@ static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, __add_wait_queue(wq, wait); /* + * Add one explicit barrier since blk_mq_get_driver_tag() may + * not imply barrier in case of failure. + * + * Order adding us to wait queue and allocating driver tag. + * + * The pair is the one implied in sbitmap_queue_wake_up() which + * orders clearing sbitmap tag bits and waitqueue_active() in + * __sbitmap_queue_wake_up(), since waitqueue_active() is lockless + * + * Otherwise, re-order of adding wait queue and getting driver tag + * may cause __sbitmap_queue_wake_up() to wake up nothing because + * the waitqueue_active() may not observe us in wait queue. + */ + smp_mb(); + + /* * It's possible that a tag was freed in the window between the * allocation failure and adding the hardware queue to the wait * queue. @@ -2575,6 +2567,7 @@ static void blk_mq_bio_to_request(struct request *rq, struct bio *bio, rq->cmd_flags |= REQ_FAILFAST_MASK; rq->__sector = bio->bi_iter.bi_sector; + rq->write_hint = bio->bi_write_hint; blk_rq_bio_prep(rq, bio, nr_segs); /* This can't fail, since GFP_NOIO includes __GFP_DIRECT_RECLAIM. */ @@ -2806,13 +2799,8 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) * If we do, we can dispatch the whole plug list in one go. We * already know at this point that all requests belong to the * same queue, caller must ensure that's the case. - * - * Since we pass off the full list to the driver at this point, - * we do not increment the active request count for the queue. - * Bypass shared tags for now because of that. */ - if (q->mq_ops->queue_rqs && - !(rq->mq_hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { + if (q->mq_ops->queue_rqs) { blk_mq_run_dispatch_ops(q, __blk_mq_flush_plug_list(q, plug)); if (rq_list_empty(plug->mq_list)) @@ -2887,9 +2875,6 @@ static struct request *blk_mq_get_new_requests(struct request_queue *q, }; struct request *rq; - if (blk_mq_attempt_bio_merge(q, bio, nsegs)) - return NULL; - rq_qos_throttle(q, bio); if (plug) { @@ -2907,20 +2892,32 @@ static struct request *blk_mq_get_new_requests(struct request_queue *q, return NULL; } -/* return true if this @rq can be used for @bio */ -static bool blk_mq_can_use_cached_rq(struct request *rq, struct blk_plug *plug, - struct bio *bio) +/* + * Check if there is a suitable cached request and return it. + */ +static struct request *blk_mq_peek_cached_request(struct blk_plug *plug, + struct request_queue *q, blk_opf_t opf) { - enum hctx_type type = blk_mq_get_hctx_type(bio->bi_opf); - enum hctx_type hctx_type = rq->mq_hctx->type; + enum hctx_type type = blk_mq_get_hctx_type(opf); + struct request *rq; - WARN_ON_ONCE(rq_list_peek(&plug->cached_rq) != rq); + if (!plug) + return NULL; + rq = rq_list_peek(&plug->cached_rq); + if (!rq || rq->q != q) + return NULL; + if (type != rq->mq_hctx->type && + (type != HCTX_TYPE_READ || rq->mq_hctx->type != HCTX_TYPE_DEFAULT)) + return NULL; + if (op_is_flush(rq->cmd_flags) != op_is_flush(opf)) + return NULL; + return rq; +} - if (type != hctx_type && - !(type == HCTX_TYPE_READ && hctx_type == HCTX_TYPE_DEFAULT)) - return false; - if (op_is_flush(rq->cmd_flags) != op_is_flush(bio->bi_opf)) - return false; +static void blk_mq_use_cached_rq(struct request *rq, struct blk_plug *plug, + struct bio *bio) +{ + WARN_ON_ONCE(rq_list_peek(&plug->cached_rq) != rq); /* * If any qos ->throttle() end up blocking, we will have flushed the @@ -2933,15 +2930,6 @@ static bool blk_mq_can_use_cached_rq(struct request *rq, struct blk_plug *plug, blk_mq_rq_time_init(rq, 0); rq->cmd_flags = bio->bi_opf; INIT_LIST_HEAD(&rq->queuelist); - return true; -} - -static void bio_set_ioprio(struct bio *bio) -{ - /* Nobody set ioprio so far? Initialize it based on task's nice value */ - if (IOPRIO_PRIO_CLASS(bio->bi_ioprio) == IOPRIO_CLASS_NONE) - bio->bi_ioprio = get_current_ioprio(); - blkcg_set_ioprio(bio); } /** @@ -2963,51 +2951,43 @@ void blk_mq_submit_bio(struct bio *bio) struct blk_plug *plug = blk_mq_plug(bio); const int is_sync = op_is_sync(bio->bi_opf); struct blk_mq_hw_ctx *hctx; - struct request *rq = NULL; unsigned int nr_segs = 1; + struct request *rq; blk_status_t ret; bio = blk_queue_bounce(bio, q); - bio_set_ioprio(bio); - if (plug) { - rq = rq_list_peek(&plug->cached_rq); - if (rq && rq->q != q) - rq = NULL; - } - if (rq) { - if (unlikely(bio_may_exceed_limits(bio, &q->limits))) { - bio = __bio_split_to_limits(bio, &q->limits, &nr_segs); - if (!bio) - return; - } - if (!bio_integrity_prep(bio)) - return; - if (blk_mq_attempt_bio_merge(q, bio, nr_segs)) - return; - if (blk_mq_can_use_cached_rq(rq, plug, bio)) - goto done; - percpu_ref_get(&q->q_usage_counter); - } else { + /* + * If the plug has a cached request for this queue, try use it. + * + * The cached request already holds a q_usage_counter reference and we + * don't have to acquire a new one if we use it. + */ + rq = blk_mq_peek_cached_request(plug, q, bio->bi_opf); + if (!rq) { if (unlikely(bio_queue_enter(bio))) return; - if (unlikely(bio_may_exceed_limits(bio, &q->limits))) { - bio = __bio_split_to_limits(bio, &q->limits, &nr_segs); - if (!bio) - goto fail; - } - if (!bio_integrity_prep(bio)) - goto fail; } - rq = blk_mq_get_new_requests(q, plug, bio, nr_segs); - if (unlikely(!rq)) { -fail: - blk_queue_exit(q); - return; + if (unlikely(bio_may_exceed_limits(bio, &q->limits))) { + bio = __bio_split_to_limits(bio, &q->limits, &nr_segs); + if (!bio) + goto queue_exit; + } + if (!bio_integrity_prep(bio)) + goto queue_exit; + + if (blk_mq_attempt_bio_merge(q, bio, nr_segs)) + goto queue_exit; + + if (!rq) { + rq = blk_mq_get_new_requests(q, plug, bio, nr_segs); + if (unlikely(!rq)) + goto queue_exit; + } else { + blk_mq_use_cached_rq(rq, plug, bio); } -done: trace_block_getrq(bio); rq_qos_track(q, rq, bio); @@ -3038,6 +3018,15 @@ done: } else { blk_mq_run_dispatch_ops(q, blk_mq_try_issue_directly(hctx, rq)); } + return; + +queue_exit: + /* + * Don't drop the queue reference if we were trying to use a cached + * request and thus didn't acquire one. + */ + if (!rq) + blk_queue_exit(q); } #ifdef CONFIG_BLK_MQ_STACKING @@ -3099,7 +3088,7 @@ blk_status_t blk_insert_cloned_request(struct request *rq) blk_mq_run_dispatch_ops(q, ret = blk_mq_request_issue_directly(rq, true)); if (ret) - blk_account_io_done(rq, ktime_get_ns()); + blk_account_io_done(rq, blk_time_get_ns()); return ret; } EXPORT_SYMBOL_GPL(blk_insert_cloned_request); @@ -3177,6 +3166,7 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, } rq->nr_phys_segments = rq_src->nr_phys_segments; rq->ioprio = rq_src->ioprio; + rq->write_hint = rq_src->write_hint; if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0) goto free_and_out; @@ -4078,15 +4068,16 @@ void blk_mq_release(struct request_queue *q) blk_mq_sysfs_deinit(q); } -static struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set, - void *queuedata) +struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set, + struct queue_limits *lim, void *queuedata) { + struct queue_limits default_lim = { }; struct request_queue *q; int ret; - q = blk_alloc_queue(set->numa_node); - if (!q) - return ERR_PTR(-ENOMEM); + q = blk_alloc_queue(lim ? lim : &default_lim, set->numa_node); + if (IS_ERR(q)) + return q; q->queuedata = queuedata; ret = blk_mq_init_allocated_queue(set, q); if (ret) { @@ -4095,20 +4086,15 @@ static struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set, } return q; } - -struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) -{ - return blk_mq_init_queue_data(set, NULL); -} -EXPORT_SYMBOL(blk_mq_init_queue); +EXPORT_SYMBOL(blk_mq_alloc_queue); /** * blk_mq_destroy_queue - shutdown a request queue * @q: request queue to shutdown * - * This shuts down a request queue allocated by blk_mq_init_queue(). All future + * This shuts down a request queue allocated by blk_mq_alloc_queue(). All future * requests will be failed with -ENODEV. The caller is responsible for dropping - * the reference from blk_mq_init_queue() by calling blk_put_queue(). + * the reference from blk_mq_alloc_queue() by calling blk_put_queue(). * * Context: can sleep */ @@ -4129,13 +4115,14 @@ void blk_mq_destroy_queue(struct request_queue *q) } EXPORT_SYMBOL(blk_mq_destroy_queue); -struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, void *queuedata, +struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, + struct queue_limits *lim, void *queuedata, struct lock_class_key *lkclass) { struct request_queue *q; struct gendisk *disk; - q = blk_mq_init_queue_data(set, queuedata); + q = blk_mq_alloc_queue(set, lim, queuedata); if (IS_ERR(q)) return ERR_CAST(q); @@ -4389,7 +4376,7 @@ static void blk_mq_update_queue_map(struct blk_mq_tag_set *set) if (set->nr_maps == 1) set->map[HCTX_TYPE_DEFAULT].nr_queues = set->nr_hw_queues; - if (set->ops->map_queues && !is_kdump_kernel()) { + if (set->ops->map_queues) { int i; /* @@ -4488,14 +4475,12 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) /* * If a crashdump is active, then we are potentially in a very - * memory constrained environment. Limit us to 1 queue and - * 64 tags to prevent using too much memory. + * memory constrained environment. Limit us to 64 tags to prevent + * using too much memory. */ - if (is_kdump_kernel()) { - set->nr_hw_queues = 1; - set->nr_maps = 1; + if (is_kdump_kernel()) set->queue_depth = min(64U, set->queue_depth); - } + /* * There is no use for more h/w queues than cpus if we just have * a single map @@ -4525,7 +4510,7 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) GFP_KERNEL, set->numa_node); if (!set->map[i].mq_map) goto out_free_mq_map; - set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues; + set->map[i].nr_queues = set->nr_hw_queues; } blk_mq_update_queue_map(set); |