Re: Dual P4 2.4Ghz Xeon With Hyperthreading enabled...

From: John Baldwin <jhb_at_FreeBSD.org>
Date: Wed, 13 Aug 2003 11:35:14 -0400 (EDT)
On 13-Aug-2003 Dr. Richard E. Hawkins wrote:
> On Tue, Aug 12, 2003 at 08:33:57PM -0500, Cagle, John (ISS-Houston) wrote:
>> I think the valid settings are only 0 or 1, with the default being 1
>> which will disable all logical CPUs.  If you want to enable the extra
>> logical CPUS, then set it to 0 (zero).  They will come online
>> immediately.
> 
> <please don't top-post; it makes following threads difficult>
> 
> That can't be right.  I've never done anything to configure the logical
> cpus on mine; they just showed up unexpectedly when i switched from
> stable to current.  Now I have:
> 
> slytherin ttyp1:hawk>sysctl -a |  grep cpu
> kern.threads.virtual_cpu: 4
> kern.ccpu: 1948
> kern.smp.cpus: 4
> hw.ncpu: 4
> machdep.cpu_idle_hlt: 1
> machdep.hlt_cpus: 10
> machdep.hlt_logical_cpus: 1
> machdep.logical_cpus_mask: 10
> 
> 
> It launches four logical cpus all on it's own.  It did panic during
> shutdown yesterday; If I read the messages right as it flashed by, it
> was because cpu#2 got the shutdown order.

Your logical CPU's aren't doing anything though, even though they are
started up.  John's explanation is correct.

-- 

John Baldwin <jhb_at_FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/
Received on Wed Aug 13 2003 - 06:34:54 UTC

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