On 6/21/22 01:11, Jan Kara wrote:
> Currently, IO priority set in task's IO context is not reflected in the
> bio->bi_ioprio for most IO (only io_uring and direct IO set it). This
> results in odd results where process is submitting some bios with one
> priority and other bios with a different (unset) priority and due to
> differing priorities bios cannot be merged. Make sure bio->bi_ioprio is
> always set on bio submission.
>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
> ---
> block/blk-mq.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index e17d822e6051..7548f8aebea8 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2793,6 +2793,9 @@ static inline struct request *blk_mq_get_cached_request(struct request_queue *q,
>
> static void bio_set_ioprio(struct bio *bio)
> {
> + /* Nobody set ioprio so far? Initialize it based on task's nice value */
> + if (IOPRIO_PRIO_CLASS(bio->bi_ioprio) == IOPRIO_CLASS_NONE)
> + bio->bi_ioprio = get_current_ioprio();
> blkcg_set_ioprio(bio);
> }
>
Looks good to me.
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
--
Damien Le Moal
Western Digital Research
