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sched: Reassign prev and switch_count when reacquire_kernel_lock() fail

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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: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <2674af741001102238w7b0ddcadref00d345e2181d11@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Yong Zhang 2010-01-11 14:21:25 +08:00 committed by Ingo Molnar
parent 50b926e439
commit 6d558c3ac9
1 changed files with 4 additions and 1 deletions
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5
kernel/sched.c
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@ -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())