From 6917ff0b5bd4139e08a3f3146529dcb3b95ba7a6 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 5 Apr 2017 12:01:30 -0700 Subject: blk-mq-sched: refactor scheduler initialization Preparation cleanup for the next couple of fixes, push blk_mq_sched_setup() and e->ops.mq.init_sched() into a helper. Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq-sched.c | 82 ++++++++++++++++++++++++++++------------------------ block/blk-mq-sched.h | 2 +- block/elevator.c | 32 ++++++++------------ 3 files changed, 57 insertions(+), 59 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index fc00f00898d34..6bd1758ea29b4 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -432,11 +432,45 @@ static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, } } -int blk_mq_sched_setup(struct request_queue *q) +static int blk_mq_sched_alloc_tags(struct request_queue *q, + struct blk_mq_hw_ctx *hctx, + unsigned int hctx_idx) +{ + struct blk_mq_tag_set *set = q->tag_set; + int ret; + + hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests, + set->reserved_tags); + if (!hctx->sched_tags) + return -ENOMEM; + + ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests); + if (ret) + blk_mq_sched_free_tags(set, hctx, hctx_idx); + + return ret; +} + +void blk_mq_sched_teardown(struct request_queue *q) { struct blk_mq_tag_set *set = q->tag_set; struct blk_mq_hw_ctx *hctx; - int ret, i; + int i; + + queue_for_each_hw_ctx(q, hctx, i) + blk_mq_sched_free_tags(set, hctx, i); +} + +int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) +{ + struct blk_mq_hw_ctx *hctx; + unsigned int i; + int ret; + + if (!e) { + q->elevator = NULL; + return 0; + } /* * Default to 256, since we don't split into sync/async like the @@ -444,49 +478,21 @@ int blk_mq_sched_setup(struct request_queue *q) */ q->nr_requests = 2 * BLKDEV_MAX_RQ; - /* - * We're switching to using an IO scheduler, so setup the hctx - * scheduler tags and switch the request map from the regular - * tags to scheduler tags. First allocate what we need, so we - * can safely fail and fallback, if needed. - */ - ret = 0; queue_for_each_hw_ctx(q, hctx, i) { - hctx->sched_tags = blk_mq_alloc_rq_map(set, i, - q->nr_requests, set->reserved_tags); - if (!hctx->sched_tags) { - ret = -ENOMEM; - break; - } - ret = blk_mq_alloc_rqs(set, hctx->sched_tags, i, q->nr_requests); + ret = blk_mq_sched_alloc_tags(q, hctx, i); if (ret) - break; + goto err; } - /* - * If we failed, free what we did allocate - */ - if (ret) { - queue_for_each_hw_ctx(q, hctx, i) { - if (!hctx->sched_tags) - continue; - blk_mq_sched_free_tags(set, hctx, i); - } - - return ret; - } + ret = e->ops.mq.init_sched(q, e); + if (ret) + goto err; return 0; -} -void blk_mq_sched_teardown(struct request_queue *q) -{ - struct blk_mq_tag_set *set = q->tag_set; - struct blk_mq_hw_ctx *hctx; - int i; - - queue_for_each_hw_ctx(q, hctx, i) - blk_mq_sched_free_tags(set, hctx, i); +err: + blk_mq_sched_teardown(q); + return ret; } int blk_mq_sched_init(struct request_queue *q) diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index a75b16b123f7a..873f9af5a35be 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -32,7 +32,7 @@ void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, struct list_head *rq_list, struct request *(*get_rq)(struct blk_mq_hw_ctx *)); -int blk_mq_sched_setup(struct request_queue *q); +int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e); void blk_mq_sched_teardown(struct request_queue *q); int blk_mq_sched_init(struct request_queue *q); diff --git a/block/elevator.c b/block/elevator.c index 01139f549b5be..f236ef1d2be99 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -242,17 +242,12 @@ int elevator_init(struct request_queue *q, char *name) } } - if (e->uses_mq) { - err = blk_mq_sched_setup(q); - if (!err) - err = e->ops.mq.init_sched(q, e); - } else + if (e->uses_mq) + err = blk_mq_init_sched(q, e); + else err = e->ops.sq.elevator_init_fn(q, e); - if (err) { - if (e->uses_mq) - blk_mq_sched_teardown(q); + if (err) elevator_put(e); - } return err; } EXPORT_SYMBOL(elevator_init); @@ -987,21 +982,18 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) } /* allocate, init and register new elevator */ - if (new_e) { - if (new_e->uses_mq) { - err = blk_mq_sched_setup(q); - if (!err) - err = new_e->ops.mq.init_sched(q, new_e); - } else - err = new_e->ops.sq.elevator_init_fn(q, new_e); - if (err) - goto fail_init; + if (q->mq_ops) + err = blk_mq_init_sched(q, new_e); + else + err = new_e->ops.sq.elevator_init_fn(q, new_e); + if (err) + goto fail_init; + if (new_e) { err = elv_register_queue(q); if (err) goto fail_register; - } else - q->elevator = NULL; + } /* done, kill the old one and finish */ if (old) { -- cgit v1.2.3