Re: [PATCH v2 2/2] sched/fair: use lsub_positive in cpu_util_next()

[Dietmar Eggemann]

On 25/02/2021 09:36, vincent.donnefort@xxxxxxx wrote:
> From: Vincent Donnefort <vincent.donnefort@xxxxxxx>
> 
> The sub_positive local version is saving an explicit load-store and is
> enough for the cpu_util_next() usage.
> 
> Signed-off-by: Vincent Donnefort <vincent.donnefort@xxxxxxx>
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 146ac9fec4b6..1364f8b95214 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -6525,7 +6525,7 @@ static unsigned long cpu_util_next(int cpu, struct task_struct *p, int dst_cpu)
>  	 * util_avg should already be correct.
>  	 */
>  	if (task_cpu(p) == cpu && dst_cpu != cpu)
> -		sub_positive(&util, task_util(p));
> +		lsub_positive(&util, task_util(p));
>  	else if (task_cpu(p) != cpu && dst_cpu == cpu)
>  		util += task_util(p);

Reviewed-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>