From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <ak@muc.de>
Subject: Re: Genapic
Date: 18 May 2005 18:56:53 +0200
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	<59ab603239858108d228c06cb9c5f543@cl.cam.ac.uk>
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Date: Wed, 18 May 2005 18:56:53 +0200
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To: Keir Fraser <Keir.Fraser@cl.cam.ac.uk>
Cc: "Subrahmanian, Raj" <raj.subrahmanian@unisys.com>, xen-devel@lists.xensource.com, "Davis,
	Jason" <jason.davis@unisys.com>, "Vessey,
	Bruce A" <Bruce.Vessey@unisys.com>
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> Shared platform code (apics and the like) has been remarkably simple. 
> This is to be expected:  processor differences aside, i386 and x86/64 
> are identical platforms. So, for example, fixing Xen's smpboot.c 

No, they are not. x86-64 is a vastly simplified "modern x86 only with
minimal bugs" platform, while i386 is a "workarounds for every bug
under the sun and all ancient features plus some non PC architectures" 
mixed bag of stuff. This leads to many differences in details.

One bigger difference is that x86-64 is also normally NUMA enabled,
while i386 normally is not. There are some others too.

-Andi