only one logical CPU used in Xeon

[Won De Erick]

--- On Tue, 3/17/09, Oliver Fromme <olli at lurza.secnetix.de> wrote:
> won.derick at yahoo.com wrote:
>  > John Baldwin wrote:
>  > > in the ULE case (though the sysctl doesn't work).  If
>  > > you use 4BSD on 7.1 
>  > > then the tunable and sysctl will work fine.
>  > > 
>  > 
>  > I tried this, but I can't see the variable being
>  > displayed.
> 
> Then your machine doesn't support hyperthreading.
> 
> The machdep.hyperthreading_allowed sysctl is only present
> if your machine actually has multiple logical CPUs.
> If you don't see that sysctl, then your processor doesn't
> have multiple hyperthreaded CPUs.
> 

Thanks for that further clarification. The dmesg has also justified this.

#dmesg
...
Cores per package: 4
...
FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
...

> If you're interested how this is done in the source, see
> the
> function cpu_hlt_setup() in
> src/sys/amd64/amd64/mp_machdep.c
> or src/sys/i386/i386/mp_machdep.c, respectively.
>