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Date: Mon, 4 Jan 2016 14:41:28 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
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Subject: Re: [PATCH v2 20/32] metag: define __smp_xxx
Message-ID: <20160104134128.GZ6344@twins.programming.kicks-ass.net>
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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?