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Date: Mon, 27 Dec 2010 11:52:03 +0100
From: Tejun Heo <tj@kernel.org>
To: Christoph Lameter <cl@linux.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>, akpm@linux-foundation.org,
        Pekka Enberg <penberg@cs.helsinki.fi>, linux-kernel@vger.kernel.org,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: Re: [cpuops cmpxchg double V1 1/4] Generic support for
 this_cpu_cmpxchg_double
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On Sat, Dec 25, 2010 at 05:55:22PM -0600, Christoph Lameter wrote:
> On Sat, 25 Dec 2010, Tejun Heo wrote:
> 
> > ABI.  But that said, it might still be problematic on other
> > architectures when we try to apply it to different architectures.  Is
> > everyone against just taking a scalar for the first variable instead
> > of taking a pointer?  I'd be happier with that than the current one.
> 
> How about replacing that with two scalars? Macro will check that the
> scalaers are properly aligned and that the second follows the first. Then
> there is also better symmetry in the parameters.
> 
> bool this_cpu_cmpxchg_double(
>           percpu_1, percpu_2
>           old_1, old_2
>           new_1, new_2
> )

Yeah, maybe.  The interface is a bit redundant but probably the most
fool proof.  I'm okay with either taking a single scalar or both.

Thanks.

-- 
tejun