Re: [PATCH]sched/rt.c: Add reschedule to switched_from_rt()

[Steven Rostedt <rostedt@goodmis.org>]

On Fri, 2012-11-23 at 00:02 +0400, Kirill Tkhai wrote:
> Reschedule rq->curr if the first RT task has just been
> pulled to the rq.
> 
> Signed-off-by: Kirill V Tkhai <tkhai@yandex.ru>
> CC: Steven Rostedt <rostedt@goodmis.org>
> CC: Ingo Molnar <mingo@kernel.org>
> CC: Peter Zijlstra <peterz@infradead.org>
> ---
>  kernel/sched/rt.c |    7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
> index 418feb0..29bda5b 100644
> --- a/kernel/sched/rt.c
> +++ b/kernel/sched/rt.c
> @@ -1889,8 +1889,11 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p)
>  	 * we may need to handle the pulling of RT tasks
>  	 * now.
>  	 */
> -	if (p->on_rq && !rq->rt.rt_nr_running)
> -		pull_rt_task(rq);
> +	if (!p->on_rq || rq->rt.rt_nr_running)
> +		return;
> +
> +	if (pull_rt_task(rq))
> +		resched_task(rq->curr);

Wow really? We never set NEED_RESCHED after pulling an RT task to a
queue that is about to run SCHED_OTHER?

Hmm, this is usually called before switched_to(), and looking at
switched_to_fair() there's a good chance that it does it.

But anyway, might as well add it here, I don't think it will hurt. The
prio_changed_rt() does it.

Acked-by: Steven Rostedt <rostedt@goodmis.org>

-- Steve

>  }
>  
>  void init_sched_rt_class(void)