Commit-ID:  7ebb66a12f85bc375beaf45ca900427fe47aa8f7
Gitweb:     https://git.kernel.org/tip/7ebb66a12f85bc375beaf45ca900427fe47aa8f7
Author:     Mel Gorman <[email protected]>
AuthorDate: Tue, 13 Feb 2018 13:37:25 +0000
Committer:  Ingo Molnar <[email protected]>
CommitDate: Wed, 21 Feb 2018 08:49:07 +0100

sched/fair: Avoid an unnecessary lookup of current CPU ID during wake_affine

The only caller of wake_affine() knows the CPU ID. Pass it in instead of
rechecking it.

Signed-off-by: Mel Gorman <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Giovanni Gherdovich <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: 
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
 kernel/sched/fair.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 820f94c..0132572 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5751,9 +5751,8 @@ wake_affine_weight(struct sched_domain *sd, struct 
task_struct *p,
 }
 
 static int wake_affine(struct sched_domain *sd, struct task_struct *p,
-                      int prev_cpu, int sync)
+                      int this_cpu, int prev_cpu, int sync)
 {
-       int this_cpu = smp_processor_id();
        int target = nr_cpumask_bits;
 
        if (sched_feat(WA_IDLE))
@@ -6376,7 +6375,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, 
int sd_flag, int wake_f
                if (cpu == prev_cpu)
                        goto pick_cpu;
 
-               new_cpu = wake_affine(affine_sd, p, prev_cpu, sync);
+               new_cpu = wake_affine(affine_sd, p, cpu, prev_cpu, sync);
        }
 
        if (sd && !(sd_flag & SD_BALANCE_FORK)) {

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