Index: kernel/generic/include/compiler/barrier.h
===================================================================
--- kernel/generic/include/compiler/barrier.h	(revision 181a746c0eb2d625af267727d01796f91915bccd)
+++ kernel/generic/include/compiler/barrier.h	(revision 14c9aa626996980664d0e365260b6510567b974f)
@@ -5,4 +5,5 @@
 #define compiler_barrier() asm volatile ("" ::: "memory")
 
+/** Forces the compiler to access (ie load/store) the variable only once. */
 #define ACCESS_ONCE(var) (*((volatile typeof(var)*)&(var)))