Re: [patch v7 16/21] sched: no balance for prefer_sibling in power scheduling

[Preeti U Murthy <preeti@linux.vnet.ibm.com>]

Hi Alex,

You can add my Reviewed-by for the below patch.

Thanks

Regards
Preeti U Murthy

On 04/04/2013 07:30 AM, Alex Shi wrote:
> In power aware scheduling, we don't want to balance 'prefer_sibling'
> groups just because local group has capacity.
> If the local group has no tasks at the time, that is the power
> balance hope so.
> 
> Signed-off-by: Alex Shi <alex.shi@intel.com>
> ---
>  kernel/sched/fair.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 0dd29f4..86221e7 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -4762,8 +4762,12 @@ static inline void update_sd_lb_stats(struct lb_env *env,
>  		 * extra check prevents the case where you always pull from the
>  		 * heaviest group when it is already under-utilized (possible
>  		 * with a large weight task outweighs the tasks on the system).
> +		 *
> +		 * In power aware scheduling, we don't care load weight and
> +		 * want not to pull tasks just because local group has capacity.
>  		 */
> -		if (prefer_sibling && !local_group && sds->this_has_capacity)
> +		if (prefer_sibling && !local_group && sds->this_has_capacity
> +				&& env->flags & LBF_PERF_BAL)
>  			sgs.group_capacity = min(sgs.group_capacity, 1UL);
> 
>  		if (local_group) {
>