hyperthreading

[Pete Wright]

On 4/15/21 4:25 PM, LuMiWa via freebsd-questions wrote:
> H1!
>
> I have FreeBSD 13.0-RELEASE on Thinkpad T495. For now I had just Intel
> processors and T495 has
>
> Machine class:	amd64
> CPU Model:	AMD Ryzen 5 PRO 3500U w/ Radeon Vega Mobile Gfx
> No. of Cores:	8
>
> I had hyperthreading disabled in boot/loader.conf:
>
> machdep.hyperthreading_allowed=0
> Is with AMD processors the same. I had also installed devcpu-data.
> Should I do the same on the laptop, please?

yes i believe the same loader knob is used for AMD cpu's.  here's one of 
my hosts with an Epyc CPU:
CPU: AMD EPYC 7302P 16-Core Processor                (3000.06-MHz 
K8-class CPU)

$ sysctl machdep.hyperthreading_allowed
machdep.hyperthreading_allowed: 1
$ sysctl hw.ncpu
hw.ncpu: 32
$


cheers,
-pete

-- 
Pete Wright
pete at nomadlogic.org
@nomadlogicLA