The following commit has been merged into the sched/core branch of tip:
Commit-ID: 64297f2b03cc7a6d0184a435f1b296beca1bedd1
Gitweb: https://git.kernel.org/tip/64297f2b03cc7a6d0184a435f1b296beca1bedd1
Author: Peng Wang <rocking@xxxxxxxxxxxxxxxxx>
AuthorDate: Sat, 11 Apr 2020 17:20:20 +08:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Thu, 30 Apr 2020 20:14:38 +02:00
sched/fair: Simplify the code of should_we_balance()
We only consider group_balance_cpu() after there is no idle
cpu. So, just do comparison before return at these two cases.
Signed-off-by: Peng Wang <rocking@xxxxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Valentin Schneider <valentin.schneider@xxxxxxx>
Reviewed-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/245c792f0e580b3ca342ad61257f4c066ee0f84f.1586594833.git.rocking@xxxxxxxxxxxxxxxxx
---
kernel/sched/fair.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3d6ce75..63419c6 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9413,7 +9413,7 @@ static int active_load_balance_cpu_stop(void *data);
static int should_we_balance(struct lb_env *env)
{
struct sched_group *sg = env->sd->groups;
- int cpu, balance_cpu = -1;
+ int cpu;
/*
* Ensure the balancing environment is consistent; can happen
@@ -9434,18 +9434,12 @@ static int should_we_balance(struct lb_env *env)
if (!idle_cpu(cpu))
continue;
- balance_cpu = cpu;
- break;
+ /* Are we the first idle CPU? */
+ return cpu == env->dst_cpu;
}
- if (balance_cpu == -1)
- balance_cpu = group_balance_cpu(sg);
-
- /*
- * First idle CPU or the first CPU(busiest) in this sched group
- * is eligible for doing load balancing at this and above domains.
- */
- return balance_cpu == env->dst_cpu;
+ /* Are we the first CPU of this group ? */
+ return group_balance_cpu(sg) == env->dst_cpu;
}
/*
|