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Subject: Re: [PATCH] blk-mq: Make blk_mq_run_hw_queue() return void
To:     John Garry <john.garry@huawei.com>, axboe@kernel.dk
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
References: <1572368370-139412-1-git-send-email-john.garry@huawei.com>
From:   Bob Liu <bob.liu@oracle.com>
Message-ID: <b488b2ee-4e0d-f7e9-6d28-6507840e6aac@oracle.com>
Date:   Thu, 31 Oct 2019 18:10:39 +0800
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On 10/30/19 12:59 AM, John Garry wrote:
> Since commit 97889f9ac24f ("blk-mq: remove synchronize_rcu() from
> blk_mq_del_queue_tag_set()"), the return value of blk_mq_run_hw_queue()
> is never checked, so make it return void, which very marginally simplifies
> the code.
> 
> Signed-off-by: John Garry <john.garry@huawei.com>
> 

Reviewed-by: Bob Liu <bob.liu@oracle.com>

> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index ec791156e9cc..8daa9740929a 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -1486,7 +1486,7 @@ void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
>  }
>  EXPORT_SYMBOL(blk_mq_delay_run_hw_queue);
>  
> -bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
> +void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
>  {
>  	int srcu_idx;
>  	bool need_run;
> @@ -1504,12 +1504,8 @@ bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
>  		blk_mq_hctx_has_pending(hctx);
>  	hctx_unlock(hctx, srcu_idx);
>  
> -	if (need_run) {
> +	if (need_run)
>  		__blk_mq_delay_run_hw_queue(hctx, async, 0);
> -		return true;
> -	}
> -
> -	return false;
>  }
>  EXPORT_SYMBOL(blk_mq_run_hw_queue);
>  
> diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
> index 0bf056de5cc3..c963038dfb92 100644
> --- a/include/linux/blk-mq.h
> +++ b/include/linux/blk-mq.h
> @@ -324,7 +324,7 @@ void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
>  void blk_mq_quiesce_queue(struct request_queue *q);
>  void blk_mq_unquiesce_queue(struct request_queue *q);
>  void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
> -bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
> +void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
>  void blk_mq_run_hw_queues(struct request_queue *q, bool async);
>  void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
>  		busy_tag_iter_fn *fn, void *priv);
>