Commit c05f8525 authored by Omar Sandoval's avatar Omar Sandoval Committed by Jens Axboe
Browse files

blk-mq-sched: make completed_request() callback more useful 



Currently, this callback is called right after put_request() and has no
distinguishable purpose. Instead, let's call it before put_request() as
soon as I/O has completed on the request, before we account it in
blk-stat. With this, Kyber can enable stats when it sees a latency
outlier and make sure the outlier gets accounted.

Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 5b727272

block/blk-mq-sched.h

+3 −8
Original line number Diff line number Diff line
@@ -82,17 +82,12 @@ blk_mq_sched_allow_merge(struct request_queue *q, struct request *rq, 
	return true;

}



static inline void

blk_mq_sched_completed_request(struct blk_mq_hw_ctx *hctx, struct request *rq)

static inline void blk_mq_sched_completed_request(struct request *rq)

{

	struct elevator_queue *e = hctx->queue->elevator;

	struct elevator_queue *e = rq->q->elevator;



	if (e && e->type->ops.mq.completed_request)

		e->type->ops.mq.completed_request(hctx, rq);



	BUG_ON(rq->internal_tag == -1);



	blk_mq_put_tag(hctx, hctx->sched_tags, rq->mq_ctx, rq->internal_tag);

		e->type->ops.mq.completed_request(rq);

}



static inline void blk_mq_sched_started_request(struct request *rq)

block/blk-mq.c

+4 −1
Original line number Diff line number Diff line
@@ -350,7 +350,7 @@ void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, 
	if (rq->tag != -1)

		blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag);

	if (sched_tag != -1)

		blk_mq_sched_completed_request(hctx, rq);

		blk_mq_put_tag(hctx, hctx->sched_tags, ctx, sched_tag);

	blk_mq_sched_restart(hctx);

	blk_queue_exit(q);

}
@@ -444,6 +444,9 @@ static void __blk_mq_complete_request(struct request *rq) 
{

	struct request_queue *q = rq->q;



	if (rq->internal_tag != -1)

		blk_mq_sched_completed_request(rq);



	blk_mq_stat_add(rq);



	if (!q->softirq_done_fn)

include/linux/elevator.h

+1 −1
Original line number Diff line number Diff line
@@ -106,7 +106,7 @@ struct elevator_mq_ops { 
	void (*insert_requests)(struct blk_mq_hw_ctx *, struct list_head *, bool);

	struct request *(*dispatch_request)(struct blk_mq_hw_ctx *);

	bool (*has_work)(struct blk_mq_hw_ctx *);

	void (*completed_request)(struct blk_mq_hw_ctx *, struct request *);

	void (*completed_request)(struct request *);

	void (*started_request)(struct request *);

	void (*requeue_request)(struct request *);

	struct request *(*former_request)(struct request_queue *, struct request *);

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