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Date: Fri, 6 May 2005 21:14:55 -0700
From: Andrew Morton <akpm@osdl.org>
To: Ricky Beam <jfbeam@bluetronic.net>
Cc: nico-kernel@schottelius.org, linux-kernel@vger.kernel.org
Subject: Re: /proc/cpuinfo format - arch dependent!
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Ricky Beam <jfbeam@bluetronic.net> wrote:
>
> Short of a kernel module to export the kernel variables, that's the only
>  damned way to find the number of cpus in a Linux system.

Question is: do you need to know the number of CPUs (why?) or do you need
to know the number of CPUs which you're currently allowed to use or do you
need to know the maximum number of CPUs which you are allowed to bind
yourself to, or what?

Probably these things can be worked out via the get/set_affinity() syscalls
and/or via the cpuset sysfs interfaces, but it isn't as simple as you're
assuming.