[PATCH 1/6 v3] sched/fair: Set next buddy for preempt short

[Vincent Guittot]

If a shorter slice task can preempt current at wakeup, we make sure that
the decision will not be overwritten in between by setting the task as the
next buddy. This still implies that the waking task remains eligible when
the scheduler will actually pick the next task to run.

Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Tested-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>
---
 kernel/sched/fair.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d78467ec6ee1..83bce5a04f3d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9903,7 +9903,7 @@ static void wakeup_preempt_fair(struct rq *rq, struct task_struct *p, int wake_f
 preempt:
 	if (preempt_action == PREEMPT_WAKEUP_SHORT) {
 		cancel_protect_slice(se);
-		clear_buddies(cfs_rq, se);
+		set_next_buddy(&p->se);
 	}
 
 	resched_curr_lazy(rq);
-- 
2.43.0