cvs commit: src/sys/amd64/amd64 mp_machdep.c src/sys/amd64/include cpufunc.h src/sys/i386/i386 mp_machdep.c src/sys/i386/include cpufunc.h

Alexey Dokuchaev danfe at FreeBSD.org
Sat May 14 02:54:59 PDT 2005


On Sat, May 14, 2005 at 05:39:07AM -0400, Colin Percival wrote:
> Alexey Dokuchaev wrote:
> > On Fri, May 13, 2005 at 12:01:20AM +0000, Jacques Vidrine wrote:
> >>  Add a knob for disabling/enabling HTT, "machdep.hyperthreading_allowed".
> >>  Default off due to information disclosure on multi-user systems.
> > 
> > Why not name it "machdep.hyperthreading_enabled" or even "machdep.htt_enabled"
> > for consistency with other ones?
> 
> I was aiming for consistency with other security-related knobs:
> 
> security.jail.set_hostname_allowed
> security.jail.sysvipc_allowed
> security.jail.chflags_allowed
> 
> I ended up putting hyperthreading_allowed under machdep rather than security
> because 4.x doesn't have a security sysctl node, but the name was chosen to
> emphasize that hyperthreading is currently something dangerous which should
> be permitted only under certain circumstances, rather than a feature which
> can be enabled or disabled however you like.

Fair enough, thanks.

./danfe


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