tree 20876852bee69d1c3835d04dcf3551e7b7d42601
parent 77f02a7acd7654cd5944f2120831d1eace94b343
author Adam Manzanares <adam.manzanares@wdc.com> 1491319514 -0700
committer Jens Axboe <axboe@fb.com> 1491341987 -0600

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>