From owner-freebsd-questions@FreeBSD.ORG Tue May 27 10:14:39 2008 Return-Path: Delivered-To: freebsd-questions@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EFEDC106566B for ; Tue, 27 May 2008 10:14:39 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (unknown [IPv6:2a01:170:102f::2]) by mx1.freebsd.org (Postfix) with ESMTP id 4FA348FC1A for ; Tue, 27 May 2008 10:14:39 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (localhost [127.0.0.1]) by lurza.secnetix.de (8.14.1/8.14.1) with ESMTP id m4RAEbDf032485; Tue, 27 May 2008 12:14:37 +0200 (CEST) (envelope-from oliver.fromme@secnetix.de) Received: (from olli@localhost) by lurza.secnetix.de (8.14.1/8.14.1/Submit) id m4RAEb6W032484; Tue, 27 May 2008 12:14:37 +0200 (CEST) (envelope-from olli) Date: Tue, 27 May 2008 12:14:37 +0200 (CEST) Message-Id: <200805271014.m4RAEb6W032484@lurza.secnetix.de> From: Oliver Fromme To: freebsd-questions@FreeBSD.ORG, s.hattori@scs.co.jp In-Reply-To: <011501c8bfcc$a3164b40$c154140a@colors.scs.co.jp> X-Newsgroups: list.freebsd-questions User-Agent: tin/1.8.3-20070201 ("Scotasay") (UNIX) (FreeBSD/6.2-STABLE-20070808 (i386)) MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.1.2 (lurza.secnetix.de [127.0.0.1]); Tue, 27 May 2008 12:14:38 +0200 (CEST) Cc: Subject: Re: FreeBSD 7.0-RELEASE: Can I specify the maximum number of cores that ?kernel can recognize ? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: freebsd-questions@FreeBSD.ORG, s.hattori@scs.co.jp List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 May 2008 10:14:40 -0000 Hattori, Shigehiro wrote: > I try to measure Bind caching name server's multi threading performance on > FreeBSD 7 , like below. > [...] > My testing machine has 8 cores. ( quad core * 2 ) > > I'd like to specify the maximum # of cores that kernel can recognize. > Can I specify the maximum # of cores with boot parameters or something ? You can reduce the MAXCPUS constant. The default is 16 on i386 and amd64. Unfortunately you have to modify a header file and recompile your kernel. The MAXCPUS constant can be found in /sys/$ARCH/include/param.h and is installed as /usr/include/machine/param.h. After reboot you can verify the new value with sysctl kern.smp.maxcpus (it's a read-only value). Best regards Oliver -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün- chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd "One of the main causes of the fall of the Roman Empire was that, lacking zero, they had no way to indicate successful termination of their C programs." -- Robert Firth