Re: [PATCH 2/2] block/mq-deadline: Switch back to a single dispatch list

[Damien Le Moal <dlemoal@kernel.org>]

On 2025/10/14 4:28, Bart Van Assche wrote:
> Commit c807ab520fc3 ("block/mq-deadline: Add I/O priority support")
> modified the behavior of request flag BLK_MQ_INSERT_AT_HEAD from
> dispatching a request before other requests into dispatching a request
> before other requests with the same I/O priority. This is not correct since
> BLK_MQ_INSERT_AT_HEAD is used when requeuing requests and also when a flush
> request is inserted.  Both types of requests should be dispatched as soon
> as possible. Hence, make the mq-deadline I/O scheduler again ignore the I/O
> priority for BLK_MQ_INSERT_AT_HEAD requests.
> 
> Cc: Damien Le Moal <dlemoal@kernel.org>
> Cc: Yu Kuai <yukuai@kernel.org>
> Reported-by: chengkaitao <chengkaitao@kylinos.cn>
> Closes: https://lore.kernel.org/linux-block/20251009155253.14611-1-pilgrimtao@gmail.com/
> Fixes: c807ab520fc3 ("block/mq-deadline: Add I/O priority support")
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>

Nice cleanup !

Reviewed-by: Damien Le Moalv <dlemoal@kernel.org>


-- 
Damien Le Moal
Western Digital Research