On a hyperthreaded system, top and gnome system monitor only report one processor

Colin Percival cperciva at freebsd.org
Thu Aug 25 07:04:58 GMT 2005


Justin R. Smith wrote:
> FreeBSD jsmith.org 6.0-BETA3 FreeBSD 6.0-BETA3 #0: Tue Aug 23 08:04:37
> EDT 2005     jsmith at jsmith.org:/usr/obj/usr/src/sys/MYKERNEL  i386
> 
> Top lists all process as being run by processor 0
> 
> The gnome system monitor lists only processor 0 as well (under gentoo
> linux it shows two).

Hyperthreading is disabled by default for security reasons.  If you want
to enable it (which is generally safe on single-user systems), you should
add the following line to /boot/loader.conf :

machdep.hyperthreading_allowed=1

Colin Percival
FreeBSD Security Officer


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