On Wed, Sep 04, 2019 at 05:42:41PM +0900, Damien Le Moal wrote:
> Instead of checking a queue tag_set BLK_MQ_F_NO_SCHED flag before
> calling elevator_init_mq() to make sure that the queue supports IO
> scheduling, use the elevator.c function elv_support_iosched() in
> elevator_init_mq(). This does not introduce any functional change but
> ensure that elevator_init_mq() does the right thing based on the queue
> settings.
>
> Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
> Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> ---
> block/blk-mq.c | 8 +++-----
> block/elevator.c | 23 +++++++++++++----------
> 2 files changed, 16 insertions(+), 15 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index b622029b19ea..13923630e00a 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2904,11 +2904,9 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
> blk_mq_add_queue_tag_set(set, q);
> blk_mq_map_swqueue(q);
>
> - if (!(set->flags & BLK_MQ_F_NO_SCHED)) {
> - ret = elevator_init_mq(q);
> - if (ret)
> - goto err_tag_set;
> - }
> + ret = elevator_init_mq(q);
> + if (ret)
> + goto err_tag_set;
>
> return q;
>
> diff --git a/block/elevator.c b/block/elevator.c
> index 86100de88883..4721834815bb 100644
> --- a/block/elevator.c
> +++ b/block/elevator.c
> @@ -619,16 +619,26 @@ int elevator_switch_mq(struct request_queue *q,
> return ret;
> }
>
> +static inline bool elv_support_iosched(struct request_queue *q)
> +{
> + if (q->tag_set && (q->tag_set->flags & BLK_MQ_F_NO_SCHED))
> + return false;
> + return true;
> +}
> +
> /*
> - * For blk-mq devices, we default to using mq-deadline, if available, for single
> - * queue devices. If deadline isn't available OR we have multiple queues,
> - * default to "none".
> + * For blk-mq devices supporting IO scheduling, we default to using mq-deadline,
> + * if available, for single queue devices. If deadline isn't available OR we
> + * have multiple queues, default to "none".
> */
> int elevator_init_mq(struct request_queue *q)
> {
> struct elevator_type *e;
> int err = 0;
>
> + if (!elv_support_iosched(q))
> + return 0;
> +
> if (q->nr_hw_queues != 1)
> return 0;
>
> @@ -706,13 +716,6 @@ static int __elevator_change(struct request_queue *q, const char *name)
> return elevator_switch(q, e);
> }
>
> -static inline bool elv_support_iosched(struct request_queue *q)
> -{
> - if (q->tag_set && (q->tag_set->flags & BLK_MQ_F_NO_SCHED))
> - return false;
> - return true;
> -}
> -
> ssize_t elv_iosched_store(struct request_queue *q, const char *name,
> size_t count)
> {
> --
> 2.21.0
>
Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
--
Ming
