Re: [RFC][PATCH v5 07/14] sched: get CPU's activity statistic

On Fri, Oct 18, 2013 at 01:52:20PM +0200, Vincent Guittot wrote:

+static int get_cpu_activity(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);
• if (sum == period) {

• u32 overload = rq->nr_running > 1 ? 1 : 0;
  

• return available_of(cpu) + overload;
  

• }
• return (sum * available_of(cpu)) / period;

I'm thinking this has a fair potential to overflow our u32, no?

+}