On 12/12/23 08:14, Bart Van Assche wrote:
> If REQ_OP_WRITE or REQ_OP_WRITE_ZEROES operations for the same zone
> originate from different cgroups that could result in different
> priorities being assigned to these operations. Do not modify the I/O
> priority of these write operations to prevent that these would be
> executed in the wrong order when using the mq-deadline I/O
...to prevent them from being executed in the wrong...
> scheduler.
>
> Cc: Damien Le Moal <dlemoal@xxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> block/blk-ioprio.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/block/blk-ioprio.c b/block/blk-ioprio.c
> index 4051fada01f1..09ce083a0e3a 100644
> --- a/block/blk-ioprio.c
> +++ b/block/blk-ioprio.c
> @@ -192,6 +192,17 @@ void blkcg_set_ioprio(struct bio *bio)
> if (!blkcg || blkcg->prio_policy == POLICY_NO_CHANGE)
> return;
>
> + /*
> + * If REQ_OP_WRITE or REQ_OP_WRITE_ZEROES operations for the same zone
> + * originate from different cgroups that could result in different
> + * priorities being assigned to these operations. Do not modify the I/O
> + * priority of these write operations to prevent that these would be
> + * executed in the wrong order when using the mq-deadline I/O
> + * scheduler.
> + */
> + if (bdev_op_is_zoned_write(bio->bi_bdev, bio_op(bio)))
Ideally, we want the bio equivalent of blk_rq_is_seq_zoned_write() here so that
writes to conventional zones are not affected (these can be reordered).
> + return;
> +
> if (blkcg->prio_policy == POLICY_PROMOTE_TO_RT ||
> blkcg->prio_policy == POLICY_NONE_TO_RT) {
> /*
--
Damien Le Moal
Western Digital Research
