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Date: Tue, 12 Jul 2011 11:47:53 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
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To: Eric Dumazet <eric.dumazet@gmail.com>
cc: Pekka Enberg <penberg@cs.helsinki.fi>,
        David Rientjes <rientjes@google.com>, "H. Peter Anvin" <hpa@zytor.com>,
        linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [slubllv7 06/17] slub: Add cmpxchg_double_slab()
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On Tue, 12 Jul 2011, Eric Dumazet wrote:

> Le mardi 12 juillet 2011 =C3=A0 10:59 -0500, Christoph Lameter a =C3=A9cr=
it :
>
> > We do not need to have _count included. This is just there because the
> > field is in the way on 64 bit and we can only do 2x 64 bit cmpxchges.  =
On
> > 32 bi we can drop _count from "counters".
> >
>
> OK, thanks for clarification.

Still I'd like to get some ideas on how to make the whole thing much
cleaner. Isnt there some way to convert a struct to an unsigned long
without going through a union? And a way to convert a struct + 32 bit
atomic_t into a 64 bit unsigned long? Would simplify things significantly.

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