Re: [PATCH] cfq-iosched: Fix update_vdisktime logic

[Vivek Goyal <vgoyal@redhat.com>]

On Tue, Jan 25, 2011 at 11:27:19AM +0800, Gui Jianfeng wrote:
> The update_vdisktime logic is broken since commit b54ce60eb7f61f8e314b8b241b0469eda3bb1d42,
> st->min_vdisktime never makes a progress. Fix it.
> 
> Thanks Vivek for pointing it out.
> 
> Signed-off-by: Gui Jianfeng <guijianfen@cn.fujitsu.com>

Thanks Gui. Looks good to me.

Acked-by: Vivek Goyal <vgoyal@redhat.com>

Thanks
Vivek

> ---
>  block/cfq-iosched.c |    6 ++----
>  1 files changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
> index f083bda..8c28f56 100644
> --- a/block/cfq-iosched.c
> +++ b/block/cfq-iosched.c
> @@ -558,15 +558,13 @@ static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime)
>  
>  static void update_min_vdisktime(struct cfq_rb_root *st)
>  {
> -	u64 vdisktime = st->min_vdisktime;
>  	struct cfq_group *cfqg;
>  
>  	if (st->left) {
>  		cfqg = rb_entry_cfqg(st->left);
> -		vdisktime = min_vdisktime(vdisktime, cfqg->vdisktime);
> +		st->min_vdisktime = max_vdisktime(st->min_vdisktime,
> +						  cfqg->vdisktime);
>  	}
> -
> -	st->min_vdisktime = max_vdisktime(st->min_vdisktime, vdisktime);
>  }
>  
>  /*
> -- 
> 1.7.1