sched/fair: Move calculate of avg_load to a better location

[ Upstream commit 0635490078 ]

In calculate_imbalance function, when the value of local->avg_load is
greater than or equal to busiest->avg_load, the calculated sds->avg_load is
not used. So this calculation can be placed in a more appropriate position.

Signed-off-by: zgpeng <zgpeng@tencent.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Samuel Liao <samuelliao@tencent.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/1649239025-10010-1-git-send-email-zgpeng@tencent.com
Stable-dep-of: 91dcf1e806 ("sched/fair: Fix imbalance overflow")
Signed-off-by: Sasha Levin <sashal@kernel.org>

kernel/sched/fair.c

@@ -9636,8 +9636,6 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
 		local->avg_load = (local->group_load * SCHED_CAPACITY_SCALE) /
 				  local->group_capacity;
 
-		sds->avg_load = (sds->total_load * SCHED_CAPACITY_SCALE) /
-				sds->total_capacity;
 		/*
 		 * If the local group is more loaded than the selected
 		 * busiest group don't try to pull any tasks.
@@ -9646,6 +9644,9 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
 			env->imbalance = 0;
 			return;
 		}
+
+		sds->avg_load = (sds->total_load * SCHED_CAPACITY_SCALE) /
+				sds->total_capacity;
 	}
 
 	/*