Re: Module Versioning Problems: How to "probe" for SMP

Hans Lermen (lermen@elserv.ffm.fgan.de)
Mon, 16 Sep 1996 16:11:46 +0200 (MET DST)

On Mon, 16 Sep 1996, Jacques Gelinas wrote:
> On Mon, 16 Sep 1996, Hans Lermen wrote:
> > On Mon, 16 Sep 1996, Jacques Gelinas wrote:
> > > I was looking for some simple way to probe the information available in
> > > /proc maybe. It there any ? Should we add one ? This would reduce the
> > > confusion.
> > A simple one is
> > cat /proc/cpuinfo | grep 'processor.:.1'
> Except that if you boot on a non-SMP (or a SMP machine with only one
> processor active), this test won't work.

On SMP kernel you have _one_ cpuinfo entry per CPU, hence

cat /proc/cpuinfo | grep processor

on 2 dual CPU board gives you

processor : 0
processor : 1

So, if the the search for 'processor.:.1' fails you are on a uniprocressor
kernel else on a SMP kernel.

However, a SMP kernel where all but one CPU is disabled will also report
'uniprocessor'.

> > cat /proc/ksyms | grep cpu_data
> This works I guess, but this is a ack. We really need something like
> /proc/smp
> or a special line at the begining of cpuinfo
> or the word SMP written in plain in /proc/version.

Agreed, that would be much clearer.

So long,
Hans
<lermen@fgan.de>