From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Thu, 6 May 2010 18:42:52 +0000 (-0700)
Subject: rcu: need barrier() in UP synchronize_sched_expedited()
X-Git-Tag: v2.6.35-rc1~521^2~11^2~1
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=fc390cde362309f6892bb719194f242c466a978b

rcu: need barrier() in UP synchronize_sched_expedited()

If synchronize_sched_expedited() is ever to be called from within
kernel/sched.c in a !SMP PREEMPT kernel, the !SMP implementation needs
a barrier().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/kernel/sched.c b/kernel/sched.c
index 155a16d52146..fbaf3128d010 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -8932,6 +8932,7 @@ struct cgroup_subsys cpuacct_subsys = {
 
 void synchronize_sched_expedited(void)
 {
+	barrier();
 }
 EXPORT_SYMBOL_GPL(synchronize_sched_expedited);