[PATCH 2/3] sched: optimize update_curr()

[Peter Zijlstra]

Skip the hard work when there is none.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Acked-by: Mike Galbraith <efault@xxxxxx>
---
 kernel/sched_fair.c |    2 ++
 1 file changed, 2 insertions(+)

Index: linux-2.6/kernel/sched_fair.c
===================================================================
--- linux-2.6.orig/kernel/sched_fair.c
+++ linux-2.6/kernel/sched_fair.c
@@ -492,6 +492,8 @@ static void update_curr(struct cfs_rq *c
 	 * overflow on 32 bits):
 	 */
 	delta_exec = (unsigned long)(now - curr->exec_start);
+	if (!delta_exec)
+		return;
 
 	__update_curr(cfs_rq, curr, delta_exec);
 	curr->exec_start = now;

-- 

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