Regional-london archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Disabling hyperthreading on Intel CPUs

Dos anyone know what happned to the machdep.hyperthreading_allowed tunable? It was definitely there in (I think) 5.x but in 8.1 it's not:

        andy@dell380:~ $ sysctl machdep.hyperthreading_allowed=0
        sysctl: unknown oid 'machdep.hyperthreading_allowed'

There are some new CPU sysctls in 8.x but they seem to disable cores rather than hyperthreading, which is enabled by default in the kernel. I would like to be able to turn off hyperthreading at runtime on a large number of HP PCs that are fitted with single quad-core CPUs without touching the BIO settings.


Home | Main Index | Thread Index | Old Index