diff options
| -rw-r--r-- | include/linux/compiler.h | 4 | ||||
| -rw-r--r-- | kernel/rcupreempt.c | 8 |
2 files changed, 3 insertions, 9 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index c8bd2daf95ec..8322141ee480 100644 --- a/include/linux/compiler.h +++ b/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/kernel/rcupreempt.c b/kernel/rcupreempt.c index 27827931ca0d..ca4bbbe04aa4 100644 --- a/kernel/rcupreempt.c +++ b/kernel/rcupreempt.c @@ -59,14 +59,6 @@ #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. */ |