sched: Revert 498657a478c60be092208422fefa9c7b248729c2

498657a478c60be092208422fefa9c7b248729c2 incorrectly assumed
that preempt wasn't disabled around context_switch() and thus
was fixing imaginary problem.  It also broke KVM because it
depended on ->sched_in() to be called with irq enabled so that
it can do smp calls from there.

Revert the incorrect commit and add comment describing different
contexts under with the two callbacks are invoked.

Avi: spotted transposed in/out in the added comment.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Avi Kivity <avi@redhat.com>
Cc: peterz@infradead.org
Cc: efault@gmx.de
Cc: rusty@rustcorp.com.au
LKML-Reference: <1259726212-30259-2-git-send-email-tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index b3d4e2be95aa..1031cae39c4c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2768,9 +2768,9 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
         prev_state = prev->state;
         finish_arch_switch(prev);
         perf_event_task_sched_in(current, cpu_of(rq));
-        fire_sched_in_preempt_notifiers(current);
         finish_lock_switch(rq, prev);
 
+        fire_sched_in_preempt_notifiers(current);
         if (mm)
                 mmdrop(mm);
         if (unlikely(prev_state == TASK_DEAD)) {