Hardware, /proc/cpuinfo disagree with smp_num_cpus

Dagda99 · 08-06-2004, 06:17 PM

Strange problem: on a dual P3 Xeon system, if I run cat /proc/cpuinfo, it shows 2 processors, processor: 0 and processor: 1. But if in a kernel module I write, say,

Code:

#include <asm/smp.h> //or #include <linux/smp.h>, both have same result

printk(KERN_ALERT "# Cpu's %i , %i", smp_num_cpus, NR_CPUS);

It prints:

Code:

# Cpu's 1 , 1

which means for some reason it only sees one CPU?

The reason that this is a problem is that in a module I'm writing, calling smp_call_function checks smp_num_cpus to make sure it isn't 1. Since it is, for some reason, it returns immediately.

Any ideas as to why this is so and how I can fix it? Googling hasn't come up with anything. Links, thoughts, anything would be helpful.
-Dagda

Dual P3 Xeon
Slackware 10.0
Linux 2.4.26
SMP enabled
Gcc 3.3.4

Dagda99 · 08-09-2004, 01:18 PM

What I've found:
for some reason, even though I've enabled SMP in menuconfig when compiling my kernel, CONFIG_SMP is not defined! Its treating my system as uniprocessor in programs, though cat /proc/cpuinfo shows 2 cpu's.
I've tried to manually define CONFIG_SMP as 1, though I get many errors at compile time for things not being defined; but even so, I shouldn't have to manually define it. And is my kernel configured to support SMP in programs?
Any ideas?