Re: [RFC][PATCH 2/4] sched: Push put_prev_task() into pick_next_task()

[Glauber Costa <glommer@parallels.com>]

On 06/14/2012 05:29 PM, Peter Zijlstra wrote:
> +static struct task_struct *
> +pick_next_task_rt(struct rq *rq, struct task_struct *prev)
>   {
> -	struct task_struct *p = _pick_next_task_rt(rq);
> +	struct task_struct *p;
> +	struct rt_rq *rt_rq =&rq->rt;
> +
> +	if (!rt_rq->rt_nr_running)
> +		return NULL;
> +
> +	if (rt_rq_throttled(rt_rq))
> +		return NULL;
> +
> +	if (prev)
> +		prev->sched_class->put_prev_task(rq, prev);
> +
it might be me, but this one sounds strange. If the responsibility of 
putting the task now lays with pic_next_task, you can't return NULL 
without doing this first.