Re: [PATCH v2 7/7] ARM: atomics: define our SMP atomics in terms of _relaxed operations

Peter Zijlstra
2015-07-16T21:08:21Z

On Thu, Jul 16, 2015 at 04:40:03PM -0400, Waiman Long wrote:
> On 07/16/2015 11:32 AM, Will Deacon wrote:
> >@@ -117,6 +115,8 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
> > #error "SMP is not supported on this platform"

^^^^^^^^^^^^^

> > #endif
> >
> >+#define xchg xchg_relaxed
>
> Is that a typo? I think xchg() needs to be a full memory barrier.

Pointless on UP.