Re: HELP: Number of CPU cores is not right

[Ron Johnson <ron.l.johnson@cox.net>]

On 06/18/2011 05:21 AM, Camaleón wrote:
> On Fri, 17 Jun 2011 20:49:41 +0200, Armin Kneip wrote:
>
> > > The computer OS running has 48-core CPU, but the OS now only can
> > > recognize 32-core of CPU.
> > > The kernel version is 2.6.26-2-amd64.
> >
> > The current Debian kernel supports only 32 cpu's. Set CONFIG_NR_CPUS to
> > 48 or higher and recompile your kernel.
>
> True! :-o
>
> sm01@stt008:~$ grep -i nr_cpus /boot/config-2.6.26-2-amd64
> CONFIG_NR_CPUS=32
>
> Where is that limit coming from? It must be a rationale for doing it so.
>
> (searching...)
>
> Ah, found this thread:
>
> Debian stock kernel config -- CONFIG_NR_CPUS=32?
> http://lists.debian.org/debian-user/2010/10/msg01391.html
>
> Oops, no rationale then :-)

I hardly call "module size blows up" to be no rationale for limiting the 
number of CPUs.

Why 32?  Well, it's a nice power of 2 and lots more than the number of 
cores in 99.9999% of all computers.

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