diff --git a/[refs] b/[refs]
index 5c2cb9dfdd97..2332f327147a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: cd95851785bcfe95fdf73689e8ecb5a1c5959231
+refs/heads/master: ded00a56e99555c3f4000ef3eebfd5fe0d574565
diff --git a/trunk/include/linux/compiler.h b/trunk/include/linux/compiler.h
index c8bd2daf95ec..8322141ee480 100644
--- a/trunk/include/linux/compiler.h
+++ b/trunk/include/linux/compiler.h
@@ -190,7 +190,9 @@ extern void __chk_io_ptr(const volatile void __iomem *);
  * ACCESS_ONCE() in different C statements.
  *
  * This macro does absolutely -nothing- to prevent the CPU from reordering,
- * merging, or refetching absolutely anything at any time.
+ * merging, or refetching absolutely anything at any time.  Its main intended
+ * use is to mediate communication between process-level code and irq/NMI
+ * handlers, all running on the same CPU.
  */
 #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
 
diff --git a/trunk/kernel/rcupreempt.c b/trunk/kernel/rcupreempt.c
index 27827931ca0d..ca4bbbe04aa4 100644
--- a/trunk/kernel/rcupreempt.c
+++ b/trunk/kernel/rcupreempt.c
@@ -58,14 +58,6 @@
 #include <linux/cpumask.h>
 #include <linux/rcupreempt_trace.h>
 
-/*
- * Macro that prevents the compiler from reordering accesses, but does
- * absolutely -nothing- to prevent CPUs from reordering.  This is used
- * only to mediate communication between mainline code and hardware
- * interrupt and NMI handlers.
- */
-#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
-
 /*
  * PREEMPT_RCU data structures.
  */