sched: fix wakeup preemption clock

Impact: sharpen the wakeup-granularity to always be against current scheduler time

It was possible to do the preemption check against an old time stamp.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
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 ad7b93be5691..88215066efae 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2266,6 +2266,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
 
         smp_wmb();
         rq = task_rq_lock(p, &flags);
+        update_rq_clock(rq);
         old_state = p->state;
         if (!(old_state & state))
                 goto out;
@@ -2323,7 +2324,6 @@ out_activate:
                 schedstat_inc(p, se.nr_wakeups_local);
         else
                 schedstat_inc(p, se.nr_wakeups_remote);
-        update_rq_clock(rq);
         activate_task(rq, p, 1);
         success = 1;