[PATCH] sched/deadline: add rq->clock update skip for dl task yield

[Wanpeng Li <wanpeng.li@linux.intel.com>]

This patch add rq->clock update skip for dl task yield to tell 
update_rq_clock() that we've just updated, so we don't do 
microscopic update in schedule() and double the fastpath cost.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
---
 kernel/sched/deadline.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 1ed6928..c397e6b 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -968,6 +968,12 @@ static void yield_task_dl(struct rq *rq)
 	}
 	update_rq_clock(rq);
 	update_curr_dl(rq);
+	/*
+	 * Tell update_rq_clock() that we've just updated,
+	 * so we don't do microscopic update in schedule()
+	 * and double the fastpath cost.
+	 */
+	rq_clock_skip_update(rq, true);
 }
 
 #ifdef CONFIG_SMP
-- 
1.9.1