[RFC PATCH v3 4/6] sched: secure access to other CPU statistics

[Peter Zijlstra]

On Fri, 2013-03-22 at 13:25 +0100, Vincent Guittot wrote:
> @@ -3364,13 +3364,16 @@ done:
>  static bool is_buddy_busy(int cpu)
>  {
>         struct rq *rq = cpu_rq(cpu);
> +       u32 sum = rq->avg.runnable_avg_sum;
> +       u32 period = rq->avg.runnable_avg_period;
> +
> +       sum = min(sum, period);

OK this makes sense; use a simple sanity constraint instead of going
overboard on serialization -- however, why is this a separate patch?

That is, this could easily be part of the patch that introduces
is_buddy_busy(); also you likely want part of this patch's changelog
to become a comment that goes right above this min() :-)