Re: [RFC PATCH v2 14/23] sched/cache: Drop prefer_sibling restriction for llc_balance

[Peter Zijlstra]

On Thu, Aug 27, 2026 at 08:28:07PM +0800, Jianyong Wu wrote:
> group_llc_balance performs balancing across LLC and NUMA domains.
> The prefer_sibling constraint unnecessarily limits its scope, so remove
> this requirement entirely from the branch condition.
> 
> Signed-off-by: Jianyong Wu <wujianyong@xxxxxxxx>
> ---
>  kernel/sched/fair.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 584297528a9e..5c35a43e5e38 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -13274,9 +13274,9 @@ static struct sched_group *sched_balance_find_src_group(struct lb_env *env)
>  	 * Try to move all excess tasks to a sibling domain of the busiest
>  	 * group's child domain.
>  	 */
> -	if (sds.prefer_sibling && local->group_type == group_has_spare &&
> -	    (busiest->group_type == group_llc_balance ||
> -	    sibling_imbalance(env, &sds, busiest, local) > 1))
> +	if (local->group_type == group_has_spare &&
> +	    ((busiest->group_type == group_llc_balance) || (sds.prefer_sibling &&
> +	    sibling_imbalance(env, &sds, busiest, local) > 1)))
>  		goto force_balance;

Not sure about blanked disable. Maybe only disable when cache aware
scheduling is present and enabled?