On 2019/03/14 21:19, Yufen Yu wrote:
> For q->poll_nsec == -1, means doing classic poll, not hybrid poll.
> We introduce a new flag BLK_MQ_POLL_CLASSIC to replace -1, which
> may make code much easier to read.
>
> Signed-off-by: Yufen Yu <yuyufen@xxxxxxxxxx>
> ---
> block/blk-mq.c | 4 ++--
> block/blk-sysfs.c | 8 ++++----
> include/linux/blkdev.h | 3 +++
> 3 files changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index a9c181603cbd..1c588e5c4a02 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2857,7 +2857,7 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
> /*
> * Default to classic polling
> */
> - q->poll_nsec = -1;
> + q->poll_nsec = BLK_MQ_POLL_CLASSIC;
>
> blk_mq_init_cpu_queues(q, set->nr_hw_queues);
> blk_mq_add_queue_tag_set(set, q);
> @@ -3392,7 +3392,7 @@ static bool blk_mq_poll_hybrid(struct request_queue *q,
> {
> struct request *rq;
>
> - if (q->poll_nsec == -1)
> + if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
> return false;
>
> if (!blk_qc_t_is_internal(cookie))
> diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
> index 59685918167e..cd127067998a 100644
> --- a/block/blk-sysfs.c
> +++ b/block/blk-sysfs.c
> @@ -360,8 +360,8 @@ static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
> {
> int val;
>
> - if (q->poll_nsec == -1)
> - val = -1;
> + if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
> + val = BLK_MQ_POLL_CLASSIC;
> else
> val = q->poll_nsec / 1000;
>
> @@ -380,8 +380,8 @@ static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
> if (err < 0)
> return err;
>
> - if (val == -1)
> - q->poll_nsec = -1;
> + if (val == BLK_MQ_POLL_CLASSIC)
> + q->poll_nsec = BLK_MQ_POLL_CLASSIC;
> else
> q->poll_nsec = val * 1000;
You are not handling negative values other than -1 here as we discussed. Any
reason for not adding the check ?
>
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 0de92b29f589..5c58a3b2bf00 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -50,6 +50,9 @@ struct blk_stat_callback;
> /* Must be consistent with blk_mq_poll_stats_bkt() */
> #define BLK_MQ_POLL_STATS_BKTS 16
>
> +/* Doing classic polling */
> +#define BLK_MQ_POLL_CLASSIC -1
> +
> /*
> * Maximum number of blkcg policies allowed to be registered concurrently.
> * Defined here to simplify include dependency.
>
--
Damien Le Moal
Western Digital Research
