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Date: Tue, 6 Mar 2007 14:10:41 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>,
       Zachary Amsden <zach@vmware.com>,
       Jeremy Fitzhardinge <jeremy@xensource.com>,
       Andrew Morton <akpm@linux-foundation.org>, Andi Kleen <ak@suse.de>
Subject: Re: [PATCH 8/8] Convert PDA into the percpu section
Message-ID: <20070306131041.GB9031@elte.hu>
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* Rusty Russell <rusty@rustcorp.com.au> wrote:

> Currently x86 (similar to x84-64) has a special per-cpu structure 
> called "i386_pda" which can be easily and efficiently referenced via 
> the %fs register.  An ELF section is more flexible than a structure, 
> allowing any piece of code to use this area.  Indeed, such a section 
> already exists: the per-cpu area.
> 
> So this patch
> (1) Removes the PDA and uses per-cpu variables for each current member.

hmm ... i very much like this, but its needs performance and kernel-size 
testing before it can move from -mm into mainline. We are now exposing 
wide ranges of the kernel to segment prefixes again. (Btw., i'd expect 
there to be a kernel size reduction.)

	Ingo