mm: mmu_notifier: make the mmu_notifier srcu static

The variable must be static especially given the variable name.

s/RCU/SRCU/ over a few comments.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mmu_notifier.c

@@ -20,7 +20,7 @@
 #include <linux/slab.h>
 
 /* global SRCU for all MMs */
-struct srcu_struct srcu;
+static struct srcu_struct srcu;
 
 /*
  * This function can't run concurrently against mmu_notifier_register
@@ -41,7 +41,7 @@ void __mmu_notifier_release(struct mm_struct *mm)
 	int id;
 
 	/*
-	 * RCU here will block mmu_notifier_unregister until
+	 * SRCU here will block mmu_notifier_unregister until
 	 * ->release returns.
 	 */
 	id = srcu_read_lock(&srcu);
@@ -302,7 +302,7 @@ void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm)
 
 	if (!hlist_unhashed(&mn->hlist)) {
 		/*
-		 * RCU here will force exit_mmap to wait ->release to finish
+		 * SRCU here will force exit_mmap to wait ->release to finish
 		 * before freeing the pages.
 		 */
 		int id;