Re: [RFC PATCH v4 08/12] sched: Add over-utilization/tipping point indicator

[Peter Zijlstra]

On Thu, Jun 28, 2018 at 12:40:39PM +0100, Quentin Perret wrote:
> @@ -5384,6 +5402,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
>  {
>  	struct cfs_rq *cfs_rq;
>  	struct sched_entity *se = &p->se;
> +	int task_new = !(flags & ENQUEUE_WAKEUP);
>  
>  	/*
>  	 * The code below (indirectly) updates schedutil which looks at
> @@ -5431,8 +5450,12 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
>  		update_cfs_group(se);
>  	}
>  
> -	if (!se)
> +	if (!se) {
>  		add_nr_running(rq, 1);
> +		if (!task_new)
> +			update_overutilized_status(rq);

I'm confused... why only for !ENQUEUE_WAKEUP and why use a local
variable for something that's used only once?

> +	}
>  
>  	hrtick_update(rq);
>  }