Re: [PATCH] x86: show cpuinfo only for online CPUs

From: Andreas Herrmann3
Date: Thu Nov 01 2007 - 13:39:34 EST

On Thu, Nov 01, 2007 at 03:12:25PM -0200, Glauber de Oliveira Costa wrote:
> did you test it in a kernel without SMP compiled in ?
> I'm a little afraid about what can happen here:

No I didn't, but should have done so - cpu_index exists only
in the SMP case ...

I'll come up with a corrected fix (adding some ifdefs).

> The attribuition of cpu_index only happens in a code that seems to be
> called for all cpus but the boot one.

Yes, just in identify_cpu and not in its "early_" variant.

> So it could even work, but as accident. Unless I'm wrong about it, I'd
> prefer to see an explicit attribution of cpu_index = 0 somewhere for the
> boot cpu.

Hmm, will look at this as well.

> Other than that, good catch! I didn't notice it, because all my present
> cpus were online in my box

You might be able to trigger it by using additional_cpus=<n> in your kernel
command line.
A second test is offlining a CPU: Then cpuinfo was still shown for the
offlined CPU.



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