From owner-freebsd-current@FreeBSD.ORG Thu May 7 13:57:45 2009 Return-Path: Delivered-To: Current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 32FBB106564A for ; Thu, 7 May 2009 13:57:45 +0000 (UTC) (envelope-from barney_cordoba@yahoo.com) Received: from web63901.mail.re1.yahoo.com (web63901.mail.re1.yahoo.com [69.147.97.116]) by mx1.freebsd.org (Postfix) with SMTP id D307A8FC15 for ; Thu, 7 May 2009 13:57:44 +0000 (UTC) (envelope-from barney_cordoba@yahoo.com) Received: (qmail 47162 invoked by uid 60001); 7 May 2009 13:57:44 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1241704664; bh=HuFlHR2sU335qZjV96HNAOvW70+Y+43k8U+kkVLxUfA=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Reply-To:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type; b=w3P1sSFr4Qm/MO0ajA8PBzMs61yaIosPINhIJ00qiVh1uiYmaTVW06p/PSeuLFSXhHB41964SoVGommXuFJ9gYmrRFz8m5T3whgNOjkHGx9ox6oD90zIrIln8vHt7tXp/FaxBy/ryTFwCbC4zwAX3wjGAFol4GeYpJPs5xrRVTM= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Reply-To:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type; b=isI5BFjDuQsv98Z5rGnl0SL0Us23RO7+IO9F+LXJ5zF0QmE70aHszdGUFIo5u5lG8Je1b6c5ND1vQriCMEViwQt0/kuilKNAvZPztrUryFn0kxMSRKkl+7Bp+NbLJWqHTvVglDz/lQB9NZekzm2PWi6qBqW3AjXQEOD3G+zAQcE=; Message-ID: <418018.46727.qm@web63901.mail.re1.yahoo.com> X-YMail-OSG: V1MCDmEVM1mOgq8NaJR4BliYaI8uTTKieq.4ehkGeAhPXh6ZVjnNa2C9tLk8dmfJLY9kkM57w3PUtfsXGUQnN6DSuNFuaWm6HWLVdfHlL8254aog1_egM3XvynXAzZSNXqyaPVV8PUch7yp88BvxWBdXEmSLPPvPGQ59Pd.VmeQY38Cnt6tAefYxwor6o_AuPKP7JpArewbItj9Nr.6C_hC9msV9XnGKV5gw._v0obZb3Cv7l0VrCH0azYNiucR4dt.GnhtuIcUb6lUgQ_1DU8vcJPCYgl08sZhYh6SFQGKvKi88YH5Rmjs- Received: from [98.242.223.106] by web63901.mail.re1.yahoo.com via HTTP; Thu, 07 May 2009 06:57:44 PDT X-Mailer: YahooMailWebService/0.7.289.1 Date: Thu, 7 May 2009 06:57:44 -0700 (PDT) From: Barney Cordoba To: pluknet In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Current@freebsd.org" Subject: Re: Hypertherading X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: barney_cordoba@yahoo.com List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 May 2009 13:57:45 -0000 --- On Wed, 5/6/09, pluknet wrote: > From: pluknet > Subject: Re: Hypertherading > To: "Barney Cordoba" > Cc: "Current@freebsd.org" > Date: Wednesday, May 6, 2009, 10:55 PM > 2009/5/7 Barney Cordoba : > > > > I just got a shiny new nehalem box and it comes up > with 16 processors with dual quads installed. Is there any > benefit or should hyperthreading be disabled? > > > > Hi. There is a measurable win if hyperthreading is enabled > [1]. > You can switch it off via machdep.hyperthreading_enabled > loader tunable. > > [1] > http://lists.freebsd.org/pipermail/freebsd-stable/2009-January/047460.html > > > -- > wbr, > pluknet I assume you mean hyperthreading-allowed? I set sysctl -a | grep hyper machdep.hyperthreading_allowed: 0 but it still launches 16 cpus. Is that expected? It doesn't seem correct. Barney