RE: [PATCH] blk-mq-tag: make blk_mq_tag_busy() return void

[Tianxianting]

Thanks for the comments,
So blk_mq_tag_idle() can be also simplified as below,  I will send v2 patch for reviewing.

static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
 {
-       if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
-               return;
-
-       __blk_mq_tag_idle(hctx);
+       if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
+               __blk_mq_tag_idle(hctx);
 }

-----Original Message-----
From: Ming Lei [mailto:ming.lei@xxxxxxxxxx] 
Sent: Thursday, December 10, 2020 12:01 PM
To: tianxianting (RD) <tian.xianting@xxxxxxx>
Cc: axboe@xxxxxxxxx; linux-block@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: [PATCH] blk-mq-tag: make blk_mq_tag_busy() return void

On Tue, Dec 08, 2020 at 03:40:02PM +0800, Xianting Tian wrote:
> As no one cares about the return value of blk_mq_tag_busy() and 
> __blk_mq_tag_busy(), so make them return void.
> 
> Signed-off-by: Xianting Tian <tian.xianting@xxxxxxx>
> ---
>  block/blk-mq-tag.c | 4 ++--
>  block/blk-mq-tag.h | 8 ++++----
>  2 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 
> 9c92053e7..21ff7d156 100644
> --- a/block/blk-mq-tag.c
> +++ b/block/blk-mq-tag.c
> @@ -21,7 +21,7 @@
>   * to get tag when first time, the other shared-tag users could reserve
>   * budget for it.
>   */
> -bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
> +void __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
>  {
>  	if (blk_mq_is_sbitmap_shared(hctx->flags)) {
>  		struct request_queue *q = hctx->queue; @@ -36,7 +36,7 @@ bool 
> __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
>  			atomic_inc(&hctx->tags->active_queues);
>  	}
>  
> -	return true;
> +	return;
>  }
>  
>  /*
> diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 
> 7d3e6b333..dd80e5a85 100644
> --- a/block/blk-mq-tag.h
> +++ b/block/blk-mq-tag.h
> @@ -60,15 +60,15 @@ enum {
>  	BLK_MQ_TAG_MAX		= BLK_MQ_NO_TAG - 1,
>  };
>  
> -extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
> +extern void __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
>  extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
>  
> -static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
> +static inline void blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
>  {
>  	if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
> -		return false;
> +		return;
>  
> -	return __blk_mq_tag_busy(hctx);
> +	__blk_mq_tag_busy(hctx);

The above can be simplified as:

  	if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
		__blk_mq_tag_busy(hctx);

Otherwise, looks fine:

Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>

Thanks,
Ming