Re: [RFC][PATCH 11/10] sched, fair: Reduce local_group logic

[Peter Zijlstra <peterz@infradead.org>]

On Wed, Aug 28, 2013 at 10:55:42AM +0200, Peter Zijlstra wrote:
> @@ -4690,19 +4694,20 @@ static inline void update_sd_lb_stats(st
>  		 * heaviest group when it is already under-utilized (possible
>  		 * with a large weight task outweighs the tasks on the system).
>  		 */
> +		if (prefer_sibling && sds->local &&
> +		    sds->local_stat.group_has_capacity)
>  			sgs->group_capacity = min(sgs->group_capacity, 1U);

While we're here, I think its always true that sds->local is set,
because env->dst_cpu should always be part of the local group and the
local group is always sd->groups and since that now directly skips to
next_group we'll not get here without this being true.

Hmm?

>  
> +		if (update_sd_pick_busiest(env, sds, sg, sgs)) {
>  			sds->busiest = sg;
>  			sds->busiest_stat = *sgs;
>  		}
>  
> +next_group:
> +		/* Now, start updating sd_lb_stats */
> +		sds->total_load += sgs->group_load;
> +		sds->total_pwr += sgs->group_power;
> +
>  		sg = sg->next;
>  	} while (sg != env->sd->groups);
>  }