From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 2 Jun 2015 15:26:48 +0000 (+0200)
Subject: rcu: Use WRITE_ONCE in RCU_INIT_POINTER
X-Git-Url: http://git.efficios.com/?a=commitdiff_plain;h=155d1d12786386d21732f9bba036343ffa43847d;p=deliverable%2Flinux.git

rcu: Use WRITE_ONCE in RCU_INIT_POINTER

For the paranoid amongst us GCC would be in its right to use byte stores
to write our NULL value, tell it not to do that.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index def6d45ad61c..c63428c1ed8a 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -995,7 +995,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
 #define RCU_INIT_POINTER(p, v) \
 	do { \
 		rcu_dereference_sparse(p, __rcu); \
-		p = RCU_INITIALIZER(v); \
+		WRITE_ONCE(p, RCU_INITIALIZER(v)); \
 	} while (0)
 
 /**