Date: Mon, 15 May 2006 11:34:39 -0700
From: Andrew Morton <akpm@osdl.org>
To: Andi Kleen <ak@suse.de>
Cc: mingo@elte.hu, apw@shadowen.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86 NUMA panic compile error
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In-Reply-To: <200605152013.53728.ak@suse.de>
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Andi Kleen <ak@suse.de> wrote:
>
> > 
> > I'll be darned.  I never knew it was even possible to run x86 numa kernels
> > on non-numa boxen.  I'd have tested about 1000000 of Christoph Lameter's
> > patches if someone had told me.  Yes, it's useful.
> 
> If you want to use it for that I would suggest to port the numa emulation
> code at least - two or four nodes tends to find more problems than a single
> node.
> 
> But testing on a 64bit box - even with numa emulation - would be much
> better because on 32bit ZONE_NORMAL often is node 0 only and you won't 
> get much numaness for kernel objects.

That's an excellent point - most developers who are likely to want to test
NUMA have x86_64 boxes and x86_64 has NUMA-emulation-on-SMP.  I'd
semi-forgotten that it existed.

This rather weakens the reasons for retaining support for
NUMA-on-non-summit-x86.  Ingo?

> > I guess the concern here is that we don't want people building these
> > frankenkernels and then sending us bug reports against them.
> 
> Well it will still increase the bug numbers you care so much about.

Not really.  If a bug affects something we don't care about (like this)
I'll just ignore it.  I care about the number of busted machines out there,
not the bug counts...

> Another reason I don't like it is that it's ugly and reimplements
> parts of ACPI on its own for no reason.

So shouldn't such a patch remove that code rather than panicing?

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