On Fri, Jul 17, 2015 at 01:00:34AM +0100, Waiman Long wrote: > On 07/16/2015 05:08 PM, Peter Zijlstra wrote: > > 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" > > ^^^^^^^^^^^^^ > > That #error is only for ARMv5 or below. > > >>> #endif > >>> > >>> +#define xchg xchg_relaxed > >> Is that a typo? I think xchg() needs to be a full memory barrier. > > Pointless on UP.
I don't see the problem here. As Peter pointed out, this code only gets looked at if !SMP and structuring it this way means I can have one definition of xchg_relaxed, regardless of architecture version. Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
