Merge "ANDROID: sched/fair: Avoid unnecessary balancing of asymmetric capacity groups" (f6017fde) · Commits · e / devices / android_kernel_fairphone_FP4

kernel/sched/fair.c

+22 −0

Original line number	Diff line number	Diff line
		@@ -9146,6 +9146,19 @@ group_smaller_max_cpu_capacity(struct sched_group sg, struct sched_group ref)
		ref->sgc->max_capacity * 1024;
		}

		/*
		* group_similar_cpu_capacity: Returns true if the minimum capacity of the
		* compared groups differ by less than 12.5%.
		*/
		static inline bool
		group_similar_cpu_capacity(struct sched_group sg, struct sched_group ref)
		{
		long diff = sg->sgc->min_capacity - ref->sgc->min_capacity;
		long max = max(sg->sgc->min_capacity, ref->sgc->min_capacity);

		return abs(diff) < max >> 3;
		}

		static inline enum
		group_type group_classify(struct sched_group *group,
		struct sg_lb_stats *sgs)
		@@ -9324,6 +9337,15 @@ static bool update_sd_pick_busiest(struct lb_env *env,
		group_smaller_min_cpu_capacity(sds->local, sg))
		return false;

		/*
		* Candidate sg doesn't face any severe imbalance issues so
		* don't disturb unless the groups are of similar capacity
		* where balancing is more harmless.
		*/
		if (sgs->group_type == group_other &&
		!group_similar_cpu_capacity(sds->local, sg))
		return false;

		/*
		* If we have more than one misfit sg go with the biggest misfit.
		*/