From: Alan <alan@lxorguk.ukuu.org.uk>
To: Ben Collins <bcollins@ubuntu.com>
Cc: linux-kernel@vger.kernel.org, torvalds@osdl.org
Subject: Re: [PATCH 1/4] [x86] Add command line option to enable/disable hyper-threading.
Date: Thu, 30 Nov 2006 11:06:11 +0000 [thread overview]
Message-ID: <20061130110611.03aff95c@localhost.localdomain> (raw)
In-Reply-To: <11648607733630-git-send-email-bcollins@ubuntu.com>
On Wed, 29 Nov 2006 23:26:05 -0500
Ben Collins <bcollins@ubuntu.com> wrote:
> This patch adds a config option to allow disabling hyper-threading by
> default, and a kernel command line option to changes this default at
> boot time.
>
> Signed-off-by: Ben Collins <bcollins@ubuntu.com>
The description is wrong - this does not disable hyperthreading it merely
leaves one thread idle. I don't believe Intel have ever published a
procedure for truely disabling HT, but if you idle a thread you may want
to adjust the cache settings on a PIV (10.5.6 in the intel docs) and set
it to shared mode. Need to play more with what the bios does I guess.
So Ack but with the proviso it should say "Ignoring" or "Not using" not
"Disabling", because it does not do the latter and there seem to be
performance differences as a result
Acked-by: Alan Cox <alan@redhat.com>
Alan
next prev parent reply other threads:[~2006-11-30 10:59 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-30 4:26 Ubuntu patch sync for 2.6.20 Ben Collins
2006-11-30 4:26 ` Ben Collins
2006-11-30 4:26 ` Ben Collins
2006-11-30 4:26 ` [PATCH 1/4] [x86] Add command line option to enable/disable hyper-threading Ben Collins
2006-11-30 11:06 ` Alan [this message]
2006-11-30 18:08 ` Siddha, Suresh B
2006-12-01 13:29 ` Pavel Machek
2006-12-01 13:41 ` Ben Collins
2006-12-01 14:32 ` Arjan van de Ven
2006-12-01 15:09 ` Ben Collins
2006-12-01 16:10 ` Arjan van de Ven
2006-12-01 16:14 ` Ben Collins
2006-12-01 16:20 ` Linus Torvalds
2006-12-01 16:56 ` Alan
2006-12-01 17:13 ` Mark Rustad
2006-11-30 4:26 ` [PATCH 2/4] [APIC] Allow disabling of UP APIC/IO-APIC by default, with command line option to turn it on Ben Collins
2006-12-01 8:39 ` Ingo Molnar
2006-12-01 20:56 ` Ben Collins
2006-12-02 8:56 ` Ingo Molnar
2006-11-30 4:26 ` [PATCH 3/4] [ATM] Add CPPFLAGS to byteorder.h check Ben Collins
2006-11-30 4:26 ` [PATCH 4/4] [HVCS] Select HVC_CONSOLE if HVCS is enabled Ben Collins
2006-11-30 12:32 ` Roman Zippel
2006-11-30 15:04 ` Ben Collins
-- strict thread matches above, loose matches on Subject: below --
2006-12-07 22:50 [PATCH 1/4] [x86] Add command line option to enable/disable hyper-threading Peter Cordes
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