Re: [PATCH] cfs: remove unused 'if' condition checking

[xingchao]

On Fri, 16 Sep 2011 16:38:32 +0800
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> Thanks, queued it as:
> 
> ---
> Subject: sched: Remove redundant test in check_preempt_tick()
> From: Wang Xingchao <xingchao.wang@xxxxxxxxx>
> Date: Fri, 16 Sep 2011 13:35:52 -0400
> 
> The caller already checks for nr_running > 1, therefore we don't have
> to do so again.
> 
> Signed-off-by: Wang Xingchao <xingchao.wang@xxxxxxxxx>
> Reviewed-by: Paul Turner <pjt@xxxxxxxxxx>
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Link:
> http://lkml.kernel.org/r/1316194552-12019-1-git-send-email-xingchao.wang@xxxxxxxxx
> --- kernel/sched_fair.c |   16 ++++++++--------
>  1 files changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
> index 1ca2cd4..fef0bfd 100644
> --- a/kernel/sched_fair.c
> +++ b/kernel/sched_fair.c
> @@ -1106,6 +1106,8 @@ static void
>  check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
>  {
>  	unsigned long ideal_runtime, delta_exec;
> +	struct sched_entity *se;
> +	s64 delta;
>  
>  	ideal_runtime = sched_slice(cfs_rq, curr);
>  	delta_exec = curr->sum_exec_runtime -
> curr->prev_sum_exec_runtime; @@ -1127,16 +1129,14 @@
> check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
> if (delta_exec < sysctl_sched_min_granularity) return;
>  
> -	if (cfs_rq->nr_running > 1) {
> -		struct sched_entity *se =
> __pick_first_entity(cfs_rq);
> -		s64 delta = curr->vruntime - se->vruntime;
> +	se = __pick_first_entity(cfs_rq);
> +	delta = curr->vruntime - se->vruntime;
>  
> -		if (delta < 0)
> -			return;
> +	if (delta < 0)
> +		return;
>  
> -		if (delta > ideal_runtime)
> -			resched_task(rq_of(cfs_rq)->curr);
> -	}
> +	if (delta > ideal_runtime)
> +		resched_task(rq_of(cfs_rq)->curr);
>  }
>  
>  static void

oh, so fast Peter, thank you. Then it's no need to take the V2 patch.

--xingchao