Re: [PATCH, RFC] sched: update_top_cache_domain only at the times ofbuilding sched domain.

[Rakib Mullick]

On Tue, Jul 23, 2013 at 10:53 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Tue, Jul 23, 2013 at 10:20:20PM +0600, Rakib Mullick wrote:
>
>> You mean using sd == NULL rather than using update_cache_domain variable ?
>
> Yes, note how:
>
> @@ -6109,7 +6110,7 @@ static void detach_destroy_domains(const struct cpumask *cpu_map)
>
>         rcu_read_lock();
>         for_each_cpu(i, cpu_map)
> -               cpu_attach_domain(NULL, &def_root_domain, i);
>         rcu_read_unlock();
>  }
>
> Always has NULL for sd? Which means you can do:
>
> @@ -5138,7 +5138,8 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
>         rcu_assign_pointer(rq->sd, sd);
>         destroy_sched_domains(tmp, cpu);
>
> -       update_top_cache_domain(cpu);
> +       if (sd)
> +               update_top_cache_domain(cpu);
>  }
>
>  /* cpus with isolated domains */

Okay, got it. Will submit an updated patch!

Thanks
Rakib.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/