Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6d558c3a authored by Yong Zhang's avatar Yong Zhang Committed by Ingo Molnar
Browse files

sched: Reassign prev and switch_count when reacquire_kernel_lock() fail 



Assume A->B schedule is processing, if B have acquired BKL before and it
need reschedule this time. Then on B's context, it will go to
need_resched_nonpreemptible for reschedule. But at this time, prev and
switch_count are related to A. It's wrong and will lead to incorrect
scheduler statistics.

Signed-off-by: default avatarYong Zhang <yong.zhang0@gmail.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <2674af741001102238w7b0ddcadref00d345e2181d11@mail.gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 50b926e4

kernel/sched.c

+4 −1
Original line number Diff line number Diff line
@@ -5530,8 +5530,11 @@ need_resched_nonpreemptible: 


	post_schedule(rq);



	if (unlikely(reacquire_kernel_lock(current) < 0))

	if (unlikely(reacquire_kernel_lock(current) < 0)) {

		prev = rq->curr;

		switch_count = &prev->nivcsw;

		goto need_resched_nonpreemptible;

	}



	preempt_enable_no_resched();

	if (need_resched())