Re: [PATCH 3/3] sched, fair: Stop searching for tasks in newidle balance if there are runnable tasks

[Morten Rasmussen]

On Thu, Apr 24, 2014 at 02:30:35AM +0100, Jason Low wrote:
> @@ -6704,7 +6703,12 @@ static int idle_balance(struct rq *this_rq)
>  		interval = msecs_to_jiffies(sd->balance_interval);
>  		if (time_after(next_balance, sd->last_balance + interval))
>  			next_balance = sd->last_balance + interval;
> -		if (pulled_task)
> +
> +		/*
> +		 * Stop searching for tasks to pull if there are
> +		 * now runnable tasks on this rq.
> +		 */
> +		if (pulled_task || this_rq->nr_running > 0)

Should this be cfs tasks instead?

+		if (pulled_task || this_rq->cfs.h_nr_running > 0)

3.15-rc2 commit 35805ff8f4fc535ac85330170d3c56829c87c677 seems to
indicate that using rq->nr_running may lead to trouble.

The other two patches look good to me.

Morten
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