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

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

[zgpeng]

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>
Reviewed-by: Samuel Liao <samuelliao@tencent.com>
---
 kernel/sched/fair.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d4bd299..601f8bd 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9460,8 +9460,6 @@ 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.
@@ -9470,6 +9468,9 @@ 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;
 	}
 
 	/*
-- 
2.9.5

Re: [PATCH] sched/fair: Move calculate of avg_load to a better location

[Vincent Guittot]

On Wed, 6 Apr 2022 at 11:57, zgpeng <zgpeng.linux@gmail.com> wrote:
>
> 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>
> Reviewed-by: Samuel Liao <samuelliao@tencent.com>

Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>

> ---
>  kernel/sched/fair.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index d4bd299..601f8bd 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -9460,8 +9460,6 @@ 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.
> @@ -9470,6 +9468,9 @@ 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;
>         }
>
>         /*
> --
> 2.9.5
>

[tip: sched/core] sched/fair: Move calculate of avg_load to a better location

[tip-bot2 for zgpeng]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     06354900787f25bf5be3c07a68e3cdbc5bf0fa69
Gitweb:        https://git.kernel.org/tip/06354900787f25bf5be3c07a68e3cdbc5bf0fa69
Author:        zgpeng <zgpeng.linux@gmail.com>
AuthorDate:    Wed, 06 Apr 2022 17:57:05 +08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 22 Apr 2022 12:14:07 +02:00

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

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
---
 kernel/sched/fair.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d4bd299..601f8bd 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9460,8 +9460,6 @@ 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.
@@ -9470,6 +9468,9 @@ 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;
 	}
 
 	/*