On 10/19/23 02:54, Bart Van Assche wrote:
> blk_mq_requeue_work() inserts requeued requests in front of other
> requests. This is fine for all request types except for sequential zoned
> writes. Hence this patch.
>
> Note: moving this functionality into the mq-deadline I/O scheduler is
> not an option because we want to be able to use zoned storage without
> I/O scheduler.
>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Damien Le Moal <dlemoal@xxxxxxxxxx>
> Cc: Ming Lei <ming.lei@xxxxxxxxxx>
> Cc: Hannes Reinecke <hare@xxxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> block/blk-mq.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 502dafa76716..ce6ddb249959 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -1485,7 +1485,9 @@ static void blk_mq_requeue_work(struct work_struct *work)
> blk_mq_request_bypass_insert(rq, 0);
> } else {
> list_del_init(&rq->queuelist);
> - blk_mq_insert_request(rq, BLK_MQ_INSERT_AT_HEAD);
> + blk_mq_insert_request(rq,
> + !blk_rq_is_seq_zoned_write(rq) ?
> + BLK_MQ_INSERT_AT_HEAD : 0);
Something like:
} else {
blk_insert_t flags = BLK_MQ_INSERT_AT_HEAD;
if (blk_rq_is_seq_zoned_write(rq))
flags = 0;
blk_mq_insert_request(rq, flags);
}
would be a lot easier to read in my opinion.
--
Damien Le Moal
Western Digital Research
