From owner-freebsd-questions@FreeBSD.ORG Thu Jan 5 17:34:07 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E507416A420 for ; Thu, 5 Jan 2006 17:34:07 +0000 (GMT) (envelope-from freebsd@walter.transip.nl) Received: from relay1.transip.nl (relay1.transip.nl [80.69.67.19]) by mx1.FreeBSD.org (Postfix) with ESMTP id 45AA443D5F for ; Thu, 5 Jan 2006 17:34:04 +0000 (GMT) (envelope-from freebsd@walter.transip.nl) Received: from quark.lfms.nl (quark.lfms.nl [81.171.100.4]) by relay1.transip.nl (Postfix) with ESMTP id F122F3C0BB9 for ; Thu, 5 Jan 2006 18:34:03 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by quark.lfms.nl (Postfix) with ESMTP id 12D2F889163 for ; Thu, 5 Jan 2006 18:34:02 +0100 (CET) Received: from epia.dt.lfms.nl (epia.tun.lfms.nl [172.20.4.1]) by quark.lfms.nl (Postfix) with ESMTP id 2012F88900C for ; Thu, 5 Jan 2006 18:33:58 +0100 (CET) Received: from avalon.dt.lfms.nl (avalon.dt.lfms.nl [172.19.6.1]) by epia.dt.lfms.nl (Postfix) with ESMTP id 6172D50BF9 for ; Thu, 5 Jan 2006 18:34:01 +0100 (CET) Date: Thu, 5 Jan 2006 18:34:52 +0100 From: Walter Hop X-Mailer: The Bat! (v3.64.01 Christmas Edition) Professional X-Priority: 3 (Normal) Message-ID: <60578543.20060105183452@lifeforms.nl> To: freebsd-questions@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Virus-Scanned: quark.lfms.nl (amavisd-new/ClamAV/SpamAssassin) Subject: Kernel forces machdep.hlt_cpus, how to change? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 05 Jan 2006 17:34:08 -0000 Hello all, I'm testing out FreeBSD 6.0R on a Dual Xeon. I want to do some benchmarking of hyperthreading before I put this machine into use, so I am trying to turn off the HLTing of logical cpu's. A stock "SMP" kernel without any options gives the following sysctl's on this machine: machdep.hlt_cpus: 10 machdep.hlt_logical_cpus: 0 machdep.logical_cpus_mask: 10 So even though I have hlt_logical_cpus at 0, the kernel seems to have decided to HLT my cpu's 8 and 2, the 'logical' threads on each Xeon I assume. I've tried to get around this by setting the following: test# cat /boot/loader.conf machdep.hlt_cpus=0 machdep.hlt_logical_cpus=0 But still after booting I get the same result with the cpu's HLTed. I'm not sure if using them for user processes actually helps, but I'd like to experiment with the setting. Any ideas how I should accomplish this? Cheers! Walter Hop Transip BV -- Transip BV | http://www.transip.nl/ Hoogwaardige Innovatie | Aangename Zekerheid