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Subject: Re: [tip:sched/core] x86/numa: Check for nonsensical topologies on
 real hw as well
From: Peter Zijlstra <peterz@infradead.org>
To: Yinghai Lu <yinghai@kernel.org>
Cc: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org,
        tj@kernel.org, tglx@linutronix.de, linux-tip-commits@vger.kernel.org
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Date: Thu, 10 May 2012 14:08:24 +0200
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On Thu, 2012-05-10 at 13:49 +0200, Peter Zijlstra wrote:
> +static bool __cpuinit match_mc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
> +{
> +       if (!topology_sane(c->cpu_index, o->cpu_index, "mc"))
> +               return false;
> +
> +       if (c->phys_proc_id == cpu_data(i).phys_proc_id)
> +               return true;
> +
> +       return false;
> +} 

Argh, that has the very same problem.. it (and the same for the other
two match funcions).

Something like:

  if (c->phys_proc_id == cpu_data(i).phys_proc_id && topology_sane())

might do, since then we only verify the topology after we would
otherwise have already accepted it.