From owner-freebsd-stable@FreeBSD.ORG  Fri Nov 30 16:15:00 2007
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 2671C16A46C;
	Fri, 30 Nov 2007 16:15:00 +0000 (UTC)
	(envelope-from kris@FreeBSD.org)
Received: from weak.local (freefall.freebsd.org [IPv6:2001:4f8:fff6::28])
	by mx1.freebsd.org (Postfix) with ESMTP id 7B13813C4CE;
	Fri, 30 Nov 2007 16:14:59 +0000 (UTC)
	(envelope-from kris@FreeBSD.org)
Message-ID: <4750370F.80806@FreeBSD.org>
Date: Fri, 30 Nov 2007 17:15:11 +0100
From: Kris Kennaway <kris@FreeBSD.org>
User-Agent: Thunderbird 2.0.0.9 (Macintosh/20071031)
MIME-Version: 1.0
To: Ivan Voras <ivoras@freebsd.org>
References: <200711291932.05614.max@love2party.net>	<E1IxtQS-000Kfz-I2@dilbert.ticketswitch.com>	<b41c75520711292059p5688a0ebled44d5b81694f539@mail.gmail.com>	<474FD17D.7080209@FreeBSD.org>
	<fipa1s$ppu$1@ger.gmane.org>
In-Reply-To: <fipa1s$ppu$1@ger.gmane.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Cc: freebsd-stable@freebsd.org
Subject: Re: Also seeing 2 x quad-core system slower that 2 x dual core
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 30 Nov 2007 16:15:00 -0000

Ivan Voras wrote:
> Kris Kennaway wrote:
> 
>> Check dmesg for the APIC numbers corresponding to the CPUs you want to
>> disable and add the corresponding entries to /boot/loader.conf, e.g.:
>>
>> hint.lapic.1.disable="1"
>> hint.lapic.3.disable="1"
>> hint.lapic.5.disable="1"
>> hint.lapic.7.disable="1"
> 
> Hi,
> 
> Do you know how his method compares to setting machdep.hlt_cpus ?

That is not supported with ULE (and will lead to deadlocks), but I don't 
know off-hand if hyperthreading virtual CPUs have their own apic...ok, 
it does on one of my systems at least, so that is probably the way to go 
when possible.

Kris