sched: turn on the use of unstable events

make use of sched-clock-unstable events.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 6150cd7..2d23450 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -68,13 +68,6 @@
 }
 
 /*
- * CPU frequency is/was unstable - start new by setting prev_clock_raw:
- */
-void sched_clock_unstable_event(void)
-{
-}
-
-/*
  * Convert user-nice values [ -20 ... 0 ... 19 ]
  * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
  * and back.
@@ -630,6 +623,20 @@
 }
 
 /*
+ * CPU frequency is/was unstable - start new by setting prev_clock_raw:
+ */
+void sched_clock_unstable_event(void)
+{
+	unsigned long flags;
+	struct rq *rq;
+
+	rq = task_rq_lock(current, &flags);
+	rq->prev_clock_raw = sched_clock();
+	rq->clock_unstable_events++;
+	task_rq_unlock(rq, &flags);
+}
+
+/*
  * resched_task - mark a task 'to be rescheduled now'.
  *
  * On UP this means the setting of the need_resched flag, on SMP it