On Mon, May 17, 2021 at 04:21:36PM +0200, Dietmar Eggemann wrote:

On 13/05/2021 17:49, Ricardo Neri wrote:

[...]

quoted

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c8c04e9d0d3b..c8b66a5d593e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c

@@ -8447,6 +8447,20 @@ group_type group_classify(unsigned int imbalance_pct,
 	return group_has_spare;
 }
 
+static inline bool
+sched_asym(struct lb_env *env, struct sd_lb_stats *sds,  struct sg_lb_stats *sgs,
+	   struct sched_group *group)
+{
+	/*
+	 * Because sd->groups starts with the local group, anything that isn't
+	 * the local group will have access to the local state.
+	 */
+	if (group == sds->local)
+		return false;

sched_asym() is called under if(!local_group ...) from
update_sg_lb_stats(). So why checking this here again?

This is true. It looks to me that this check is not needed. I makes
sense to me to keep the check in update_sg_lb_stats() so that we can
avoid the extra checks, right?

Thanks and BR,
Ricardo