Fujitsu Siemens TX600 S3 performance issue

John Baldwin jhb at freebsd.org
Tue Feb 6 17:24:38 UTC 2007


On Tuesday 06 February 2007 03:34, Ludger Bolmerg wrote:
> 
> > -----Ursprüngliche Nachricht-----
> 
> > > Hi
> > > 
> > > I installed FreeBSD 6.2 on a Fujitsu Siemens TX600 S3 with 2 dual core 
> > > Xeon processors and 4G RAM.
> > > 
> > > The SMP kernel is awfully slow.  make buildkernel takes about 6 hours to 
> > > complete.  When I boot a UP kernel the build completes within 12 
> > > minutes.  I don't see any unusual message in any log file.
> > 
> > Can you run top and see what the system is doing?  That sounds very odd.  If 
> > you boot the SMP kernel with 'kern.smp.disabled=1' set via the loader is it 
> > still really slow?
> 
> Booting the SMP kernel with kern.smp.disabled=1 shows good performance values.

Ok, can you try leaving SMP enabled but disabling specific cores instead.
You do this via the APIC ID like so:

hint.lapic.10.disabled=1

Don't disable the BSP (I think it's ignored), and I would try disabling all
3 AP's at first and then enable the CPUs one a time to compare having 2 CPUs
vs 3 CPUs vs 4 CPUs.

-- 
John Baldwin


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