Commit 1b0cab32 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

mq-deadline: don't call req_get_ioprio from the I/O completion handler 



req_get_ioprio looks at req->bio to find the I/O priority, which is not
set when completing bios that the driver fully iterated through.

Stash away the dd_per_prio in the elevator private data instead of looking
it up again to optimize the code a bit while fixing the regression from
removing the per-request ioprio value.

Fixes: 6975c1a4 ("block: remove the ioprio field from struct request")
Reported-by: default avatarChris Bainbridge <chris.bainbridge@gmail.com>
Reported-by: default avatarSam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Tested-by: default avatarChris Bainbridge <chris.bainbridge@gmail.com>
Tested-by: default avatarSam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20241126102136.619067-1-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0b83c86b

block/mq-deadline.c

+4 −9
Original line number Diff line number Diff line
@@ -685,10 +685,9 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, 


	prio = ioprio_class_to_prio[ioprio_class];

	per_prio = &dd->per_prio[prio];

	if (!rq->elv.priv[0]) {

	if (!rq->elv.priv[0])

		per_prio->stats.inserted++;

		rq->elv.priv[0] = (void *)(uintptr_t)1;

	}

	rq->elv.priv[0] = per_prio;



	if (blk_mq_sched_try_insert_merge(q, rq, free))

		return;
@@ -753,18 +752,14 @@ static void dd_prepare_request(struct request *rq) 
 */

static void dd_finish_request(struct request *rq)

{

	struct request_queue *q = rq->q;

	struct deadline_data *dd = q->elevator->elevator_data;

	const u8 ioprio_class = dd_rq_ioclass(rq);

	const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];

	struct dd_per_prio *per_prio = &dd->per_prio[prio];

	struct dd_per_prio *per_prio = rq->elv.priv[0];



	/*

	 * The block layer core may call dd_finish_request() without having

	 * called dd_insert_requests(). Skip requests that bypassed I/O

	 * scheduling. See also blk_mq_request_bypass_insert().

	 */

	if (rq->elv.priv[0])

	if (per_prio)

		atomic_inc(&per_prio->stats.completed);

}