From owner-freebsd-threads@FreeBSD.ORG Mon May 31 08:35:40 2004 Return-Path: Delivered-To: freebsd-threads@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2A4AF16A4CE for ; Mon, 31 May 2004 08:35:40 -0700 (PDT) Received: from mail.pcnet.com (mail.pcnet.com [204.213.232.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id AE2F743D2D for ; Mon, 31 May 2004 08:35:39 -0700 (PDT) (envelope-from eischen@vigrid.com) Received: from mail.pcnet.com (mail.pcnet.com [204.213.232.4]) by mail.pcnet.com (8.12.10/8.12.1) with ESMTP id i4VFZc6k012125; Mon, 31 May 2004 11:35:38 -0400 (EDT) Date: Mon, 31 May 2004 11:35:38 -0400 (EDT) From: Daniel Eischen X-Sender: eischen@pcnet5.pcnet.com To: Chris Elsworth In-Reply-To: <20040531135805.GA60731@shagged.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: freebsd-threads@freebsd.org Subject: Re: Something we overlooked with MySQL and FreeBSD vs Linux? X-BeenThere: freebsd-threads@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Threading on FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 31 May 2004 15:35:40 -0000 On Mon, 31 May 2004, Chris Elsworth wrote: > Sorry to drag this up again :) > > I would check myself, but I don't have access to a HT enabled machine > with FreeBSD on it anymore to check the now-default setting of this > sysctl. The last entry in UPDATING records that > machdep.hlt_logical_cpus is 1, stopping user processes from using the > logical CPUs. > > Is this still the case? I never knew about that to tweak it. I know, I > should have read UPDATING. > > If that is still 1 as default, that might explain my 50% performance > loss on FreeBSD. I don't either, but FreeBSD's performance on HT machines is not very good yet. I seem to recall some earlier reports of disabling HT and getting better performance. I think the kernel scheduler isn't yet tuned to handle HT well. -- DE