How is hyperthreading handled on amd64?

[Bill Moran]

On Tue, 14 Mar 2006 10:41:17 -0500
John Baldwin <jhb at freebsd.org> wrote:

[snip]

> > > This is a dmesg from an SMP kernel this time. :)
> > > 
> > > Can you provide the output from 'sysctl machdep'?
> >
> > machdep.hlt_cpus: 2
> > machdep.hlt_logical_cpus: 0
> > machdep.logical_cpus_mask: 2
> > machdep.hyperthreading_allowed: 0
> 
> Ok, the mask is right (CPU 1 is marked as a hyperthread), and
> it's marked as disabled in hlt_cpus.  I think I know what is
> happening.  Can you update to the latest RELENG_6 and see if the
> issue still occurs.

Just finished.  The newly built kernel seems to be acting the same
as the 6.0-RELEASE kernel was.  (i.e. the problem is still there)
Are there any specific tests you'd like me to perform, or any other
information you'd like me to gather?

-- 
Bill Moran
Collaborative Fusion Inc.