sched: Maintain per-rq runnable averages

Since runqueues do not have a corresponding sched_entity we instead embed a
sched_avg structure directly.

Signed-off-by: Ben Segall <bsegall@google.com>
Reviewed-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120823141506.442637130@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 7a7db09..14b5719 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -467,6 +467,8 @@
 #ifdef CONFIG_SMP
 	struct llist_head wake_list;
 #endif
+
+	struct sched_avg avg;
 };
 
 static inline int cpu_of(struct rq *rq)