Re: [patch v5 09/15] sched: add power aware scheduling in fork/exec/wake

Peter Zijlstra
2013-02-20T09:43:04Z

On Mon, 2013-02-18 at 13:07 +0800, Alex Shi wrote:
> +/*
> + * Try to collect the task running number and capacity of the group.
> + */
> +static void get_sg_power_stats(struct sched_group *group,
> + struct sched_domain *sd, struct sg_lb_stats *sgs)
> +{
> + int i;
> +
> + for_each_cpu(i, sched_group_cpus(group)) {
> + struct rq *rq = cpu_rq(i);
> +
> + sgs->group_utils += rq->nr_running;
> + }
> +
> + sgs->group_capacity = DIV_ROUND_CLOSEST(group->sgp->power,
> + SCHED_POWER_SCALE);
> + if (!sgs->group_capacity)
> + sgs->group_capacity = fix_small_capacity(sd, group);
> + sgs->group_weight = group->group_weight;
> +}

So you're trying to compute the group utilization, but what does that
have to do with nr_running? In an earlier patch you introduced the
per-cpu utilization, so why not avg that to compute the group
utilization?