Date: Wed, 26 Mar 2008 12:16:41 -0700 (PDT)
From: Christoph Lameter <clameter@sgi.com>
To: Mike Travis <travis@sgi.com>
cc: Adrian Bunk <bunk@kernel.org>, Andrew Morton <akpm@linux-foundation.org>,
       linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] x86: Modify Kconfig to allow up to 4096 cpus
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On Wed, 26 Mar 2008, Mike Travis wrote:

> I guess the main effect is that "MAXSMP" represents what's really
> usable for an architecture based on other factors.  The limit of
> NODES_SHIFT = 15 is that it's represented in some places as a signed
> 16-bit value, so 15 is the hard limit without coding changes, not
> an architecture limit.

NODES_SHIFT also controls how many page flag bits are set aside for the 
node number. If you limit x86_64 to 512 nodes then lets keep this at 9.
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