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Date: Fri, 21 Jan 2011 14:32:40 -0500
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Tejun Heo <tj@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>, Pekka Enberg <penberg@cs.helsinki.fi>,
        Christoph Lameter <cl@linux.com>, akpm@linux-foundation.org,
        linux-kernel@vger.kernel.org, Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [cpuops cmpxchg double V2 1/4] Generic support for
	this_cpu_cmpxchg_double
Message-ID: <20110121193240.GA13581@Krystal>
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* Tejun Heo (tj@kernel.org) wrote:
[...]
> > (note: packed here along with "aligned" does _not_ generate ugly
> > bytewise read/write memory ops like "packed" alone. The use of
> > "packed" is to let the compiler down-align the structure to the
> > value requested, instead of uselessly aligning it on 32-byte if it
> > chooses to.)
> 
> Yeah, good point.  :-)

For the records, I just noticed that "packed, aligned(8)" can generate unaligned
accesses on sparc64 by removing the padding between a "int" and a following
pointer. So we should not use it.

Thanks,

Mathieu

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com