From: Li Zefan <lizf@cn.fujitsu.com>
Date: Thu, 26 Feb 2009 07:40:15 +0000 (+0800)
Subject: cpuacct: add a branch prediction
X-Git-Tag: upstream/snapshot3+hdmi~19921^2~17
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c40c6f85a7594ad842233885386a0ca4cd40eafe;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

cpuacct: add a branch prediction

cpuacct_charge() is in fast-path, and checking of !cpuacct_susys.active
always returns false after cpuacct has been initialized at system boot.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/kernel/sched.c b/kernel/sched.c
index 5475d56..8e63ffb 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -9684,7 +9684,7 @@ static void cpuacct_charge(struct task_struct *tsk, u64 cputime)
 	struct cpuacct *ca;
 	int cpu;
 
-	if (!cpuacct_subsys.active)
+	if (unlikely(!cpuacct_subsys.active))
 		return;
 
 	cpu = task_cpu(tsk);