Re: [PATCH] block: add a new flag BLK_MQ_POLL_HYBRID_INVALID for hybrid poll

[Marcos Paulo de Souza <marcos.souza.org@gmail.com>]

Hello Yufen,

On 2/27/19 3:21 AM, Yufen Yu wrote:
> For q->poll_nsec == -1, means using classic poll, not hybrid poll.
> We introduce a new flag BLK_POLL_DELAY_INVALID to replace -1, which
> may make code much easier to read.

In the commit message you say BLK_POLL_DELAY_INVALID, but the code and 
the commit title use BLK_MQ_POLL_HYBRID_INVALID. Is this a typo?

Thanks.

> 
> Signed-off-by: Yufen Yu <yuyufen@huawei.com>
> ---
>   block/blk-mq.c         | 4 ++--
>   block/blk-sysfs.c      | 4 ++--
>   include/linux/blkdev.h | 3 +++
>   3 files changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 9437a5eb07cf..8df9f6e97d2e 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_HYBRID_INVALID;
>   
>   	blk_mq_init_cpu_queues(q, set->nr_hw_queues);
>   	blk_mq_add_queue_tag_set(set, q);
> @@ -3389,7 +3389,7 @@ 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_HYBRID_INVALID)
>   		return false;
>   
>   	if (!blk_qc_t_is_internal(cookie))
> diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
> index 590d1ef2f961..8775b898f96d 100644
> --- a/block/blk-sysfs.c
> +++ b/block/blk-sysfs.c
> @@ -360,7 +360,7 @@ static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
>   {
>   	int val;
>   
> -	if (q->poll_nsec == -1)
> +	if (q->poll_nsec == BLK_MQ_POLL_HYBRID_INVALID)
>   		val = -1;
>   	else
>   		val = q->poll_nsec / 1000;
> @@ -381,7 +381,7 @@ static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
>   		return err;
>   
>   	if (val == -1)
> -		q->poll_nsec = -1;
> +		q->poll_nsec = BLK_MQ_POLL_HYBRID_INVALID;
>   	else
>   		q->poll_nsec = val * 1000;
>   
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 338604dff7d0..2102447b67d9 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
>   
> +/* Using default classic polling */
> +#define BLK_MQ_POLL_HYBRID_INVALID -1
> +
>   /*
>    * Maximum number of blkcg policies allowed to be registered concurrently.
>    * Defined here to simplify include dependency.
>