FreeBSD 8.0, Intel Xeon E5530, Dell R410, only 2 cores available

Ivan Voras ivoras at freebsd.org
Mon Feb 1 14:56:36 UTC 2010


On 01/30/10 00:28, Hoang V.D. | Creative Solutions GmbH wrote:

> FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
> FreeBSD/SMP: 1 package(s) x 2 core(s) x 2 SMT threads

> We was expecting to see "1 package(s) x 4 core(s) x 2 SMT threads" and 8 usable "cpus"
> Instead. According to sysctl:
>
> kern.smp.cpus: 4
> kern.smp.maxcpus: 32
> hw.ncpu: 4
> machdep.hlt_cpus: 0
>
> We have made no change to the BIOS settings (all settings are set by default by Dell).
> Could anyone help us with an explanation for this issue?

Your CPU count is wrong. The topology might be wrong for Nehalems but it 
would be wrong in a different way.

Before you can debug the FreeBSD side you should first make the hw.ncpu 
setting equal the "right" total number of logical CPUs available, e.g. 
by configuring your BIOS, upgrading your BIOS, etc.

After you configure your BIOS to recognize all the CPUs, you can 
proceed, if necessary, to debug the CPU topology.




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