Commit 85003a44 authored Apr 04, 2017 by Adam Manzanares Committed by Jens Axboe Apr 04, 2017

block: fix inheriting request priority from bio



In 4.10 I introduced a patch that associates the ioc priority with
each request in the block layer. This work was done in the single queue
block layer code. This patch unifies ioc priority to request mapping across
the single/multi queue block layers.

I have tested this patch with the null block device driver with the following
parameters.

null_blk queue_mode=2 irqmode=0 use_per_node_hctx=1 nr_devices=1

I have not seen a performance regression with this patch and I would appreciate
any feedback or additional testing.

I have also verified that io priorities are passed to the device when using
the SQ and MQ path to a SATA HDD that supports io priorities.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Adam Manzanares <adam.manzanares@wdc.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent 77f02a7a

block/blk-core.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1149,7 +1149,6 @@ static struct request __get_request(struct request_list rl, unsigned int op,

		blk_rq_init(q, rq);
		blk_rq_set_rl(rq, rl);
		blk_rq_set_prio(rq, ioc);
		rq->cmd_flags = op;
		rq->rq_flags = rq_flags;

		@@ -1636,6 +1635,7 @@ void init_request_from_bio(struct request req, struct bio bio)

		req->errors = 0;
		req->__sector = bio->bi_iter.bi_sector;
		blk_rq_set_prio(req, rq_ioc(bio));
		if (ioprio_valid(bio_prio(bio)))
		req->ioprio = bio_prio(bio);
		blk_rq_bio_prep(req->q, req, bio);

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