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Re: [Xen-devel] [PATCH]x86: Increase the default NR_CPUS to 128.

To: Jan Beulich <JBeulich@xxxxxxxxxx>, Xiantao Zhang <xiantao.zhang@xxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH]x86: Increase the default NR_CPUS to 128.
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Wed, 10 Mar 2010 14:21:46 +0000
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On 10/03/2010 13:29, "Jan Beulich" <JBeulich@xxxxxxxxxx> wrote:

>>>> "Zhang, Xiantao" <xiantao.zhang@xxxxxxxxx> 09.03.10 02:51 >>>
>> x86: Increase the default NR_CPUS to 128.
> While I realize my reply is a little late, I'd still like to raise the
> question
> about the tools side not coping with the new default - I would think
> that any default setting ought to imply that (within the scope of a
> project) the whole software stack should still work. At the very
> minimum CPU affinity changes (default settings on NUMA as well as
> manual ones through xm) do not presently work for CPUs beyond 64.

It would certainly be nice, but at least we can boot all CPUs and run VMs
across them, minus the finer-grained control. Is this halfway default
solution for these bigger machines worse than not making an effort at all?
At the end of the day packagers can make up their own minds.

 -- Keir

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