Subject: Re: [PATCH v2 20/32] metag: define __smp_xxx

From: Peter Zijlstra <[email-masked]>
Date: Mon, 4 Jan 2016 14:41:28 +0100

On Thu, Dec 31, 2015 at 09:08:22PM +0200, Michael S. Tsirkin wrote:
> +#ifdef CONFIG_SMP
> +#define fence() metag_fence()
> +#else
> +#define fence()		do { } while (0)
>  #endif

James, it strikes me as odd that fence() is a no-op instead of a
barrier() for UP, can you verify/explain?