Re: FreeBSD Security Advisory FreeBSD-SA-05:09.htt [REVISED]
From: Colin Percival (cperciva_at_freebsd.org)
Date: 05/14/05
- Previous message: Chris: "Re: FreeBSD Security Advisory FreeBSD-SA-05:09.htt [REVISED]"
- In reply to: Chris: "Re: FreeBSD Security Advisory FreeBSD-SA-05:09.htt [REVISED]"
- Next in thread: Poul-Henning Kamp: "Re: FreeBSD Security Advisory FreeBSD-SA-05:09.htt [REVISED]"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] [ attachment ]
Date: Sat, 14 May 2005 03:14:50 -0400 To: Chris <chrcoluk@gmail.com>
Chris wrote:
> I am somewhat confused by applying the patch, does this disable HTT
> functionality? or does a patched server close the issue and keep HTT
> enabled?
The patch adds a new loader tunable, machdep.hyperthreading_allowed,
which is set to 0 by default. Regardless of how you try to set the
machdep.hlt_cpus_mask and machdep.hlt_logical_cpus sysctls, if
machdep.hyperthreading_allowed is set to zero then you will not
have any process threads executing on the second hyper-thread from
each core.
If you're on a system where this isn't a problem (e.g., anything with
no local users), you can set machdep.hyperthreading_allowed=1 in
/boot/loader.conf or via the sysctl after booting, and get the benefit
of hyperthreading.
Colin Percival
_______________________________________________
freebsd-security@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-security
To unsubscribe, send any mail to "freebsd-security-unsubscribe@freebsd.org"
- Previous message: Chris: "Re: FreeBSD Security Advisory FreeBSD-SA-05:09.htt [REVISED]"
- In reply to: Chris: "Re: FreeBSD Security Advisory FreeBSD-SA-05:09.htt [REVISED]"
- Next in thread: Poul-Henning Kamp: "Re: FreeBSD Security Advisory FreeBSD-SA-05:09.htt [REVISED]"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] [ attachment ]
Relevant Pages
|
|
