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

[Vincent Guittot]

On 26 March 2013 13:50, Peter Zijlstra <peterz at infradead.org> wrote:
> 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?

There is no real reason other than explaining why I have added this
additional check

>
> 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() :-)

Yes, i 'm going to do that

>