Running SMP kernel but only one cpu

Adam Vande More amvandemore at
Sat May 2 03:18:34 UTC 2009

Duane wrote:
> I have a fairly new install of 6.4, done over the 'net, on this old
> Micron full tower dual PPro-180. The SMP kernel was automagically
> installed:
> # uname -a
> FreeBSD 6.4-RELEASE FreeBSD 6.4-RELEASE #0: Wed
> Nov 26 12:11:16 UTC 2008
> root at  i386
> Performance was *rather* sluggish so I tried to ascertain if both
> processors were running:
> # dmesg | grep cpu
> cpu0 on motherboard
> Q1. Is there a better way to establish how many processors are running?
> Q2. Do I need to specify, say in rc.conf, that I *want* SMP to be enabled?
> Best regards,
top should display a C column with a number that represents which cpu 
the process is running on.  IIRC, ACPI must be enabled for SMP to work, 
and ACPI didn't work on my MB until 7.0.  We have different boards, but 
upgrading to 7.2 would probably be a good idea if possibile in your 
situation as both 7.0 and 7.1 saw significant performance increases in 
certain areas.

also "sysctl -a |grep kern.smp.cpus" should return your cpu # for 
7.x(not sure on 6 anymore).

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