Re: [PATCH v2 11/13] sched/fair: Avoid pulling tasks from non-overloaded higher capacity groups

[Peter Zijlstra]

On Wed, Jun 22, 2016 at 06:03:22PM +0100, Morten Rasmussen wrote:
> @@ -6892,6 +6903,19 @@ static bool update_sd_pick_busiest(struct lb_env *env,
>  	if (sgs->avg_load <= busiest->avg_load)
>  		return false;
>  
> +	if (!(env->sd->flags & SD_ASYM_CPUCAPACITY))
> +		goto asym_packing;

Does this rely on the 'funny' ASYM_CAP semantics?

> +
> +	/* Candidate sg has no more than one task per cpu and has

Tssk, borken comment style.

> +	 * higher per-cpu capacity. Migrating tasks to less capable
> +	 * cpus may harm throughput. Maximize throughput,
> +	 * power/energy consequences are not considered.
> +	 */
> +	if (sgs->sum_nr_running <= sgs->group_weight &&
> +	    group_smaller_cpu_capacity(sds->local, sg))
> +		return false;
> +
> +asym_packing:
>  	/* This is the busiest node in its class. */
>  	if (!(env->sd->flags & SD_ASYM_PACKING))
>  		return true;
> -- 
> 1.9.1
>