Re: [PATCH] irq: Add node_affinity CPU masks for smarter irqbalance hints

From: Andi Kleen
Date: Wed Nov 25 2009 - 06:50:30 EST


On Wed, Nov 25, 2009 at 12:35:03PM +0100, Eric Dumazet wrote:
> > You seem to only have 8 CPUs (one socket) Normally a dual socket nehalem
> > should have 16 with HyperThreading enabled.
> >
> > For some reason the BIOS is not reporting the other CPU.
> >
> > You could double check with acpidmp / iasl -d if that's
> > what the BIOS really reports, but normally it should work.
> >
>
> Good Lord, I had a CONFIG_NR_CPUS=16 in my .config.

That should be enough for a two socket (2S x 4C x 2T) today,
but of course that will eventually change too.

> Changing to to 32 or 64 seems better :)

That looks weird. It should have worked with CONFIG_NR_CPUS==16 too,
because you only have 16 CPUs and the NR_CPUS should affect APIC
ranges etc.

Something still fishy. I would properly report it.

BTW kernel should give some error message in any case when
there are not enough CPUs I guess.

-Andi

--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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