From owner-freebsd-smp@FreeBSD.ORG Tue Mar 10 15:14:38 2009 Return-Path: Delivered-To: freebsd-smp@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4BE88106574F for ; Tue, 10 Mar 2009 15:14:38 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 1A3128FC28 for ; Tue, 10 Mar 2009 15:14:38 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from server.baldwin.cx (pool-98-109-39-197.nwrknj.fios.verizon.net [98.109.39.197]) by cyrus.watson.org (Postfix) with ESMTPSA id B522446B5B; Tue, 10 Mar 2009 11:14:37 -0400 (EDT) Received: from localhost (john@localhost [127.0.0.1]) (authenticated bits=0) by server.baldwin.cx (8.14.3/8.14.3) with ESMTP id n2AFEVT3026960; Tue, 10 Mar 2009 11:14:31 -0400 (EDT) (envelope-from jhb@freebsd.org) From: John Baldwin To: freebsd-smp@freebsd.org Date: Tue, 10 Mar 2009 11:14:20 -0400 User-Agent: KMail/1.9.7 References: <719357.64276.qm@web45802.mail.sp1.yahoo.com> In-Reply-To: <719357.64276.qm@web45802.mail.sp1.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200903101114.20634.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [127.0.0.1]); Tue, 10 Mar 2009 11:14:31 -0400 (EDT) X-Virus-Scanned: ClamAV 0.94.2/9084/Tue Mar 10 03:11:13 2009 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=4.2 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: Robert Heron , Won De Erick Subject: Re: only one logical CPU used in Xeon X-BeenThere: freebsd-smp@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: FreeBSD SMP implementation group List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Mar 2009 15:14:39 -0000 On Tuesday 10 March 2009 10:43:01 am Won De Erick wrote: > > Hi, > > I also have boxes with several Intel Xeon dual-core processors, and also got same results. > > With FreeBSD 6.2R: > #sysctl -a | grep pci.enable > hw.pci.enable_io_modes: 1 > > I think 6.2 uses legacy interrupt (INTx) which allows sharing of IRQs and is CPU bounded(?). It is also probable that even MSI/MSIX-supported NIC drivers are used here, 6.2R still used the traditional interrupt mechanism. > > With FreeBSD 7.1: > #sysctl -a | grep pci.enable > hw.pci.enable_msix: 1 > hw.pci.enable_msi: 1 > hw.pci.enable_io_modes: 1 > > Google would tell us that MSI/MSI-X allows control over which processor is chosen as the interrupt target. Does this explain the result? MSI won't determine which CPUs are used. Probably the submitter needs to try 6.4. My guess is that 6.2 thinks his extra cores are hyperthreads and thus has them disabled by default. You can toggle machdep.hyperthreading_allowed (sysctl) if that is the case, but upgrading to 6.4 is probably better. -- John Baldwin