From owner-freebsd-stable@FreeBSD.ORG Tue Dec 13 11:04:42 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5B5641065672 for ; Tue, 13 Dec 2011 11:04:42 +0000 (UTC) (envelope-from george+freebsd@m5p.com) Received: from mailhost.m5p.com (ip-3-2-0-2.r20.asbnva02.us.ce.gin.ntt.net [IPv6:2001:418:0:5000::16]) by mx1.freebsd.org (Postfix) with ESMTP id 11AE18FC19 for ; Tue, 13 Dec 2011 11:04:41 +0000 (UTC) Received: from wonderland.m5p.com (wonderland.m5p.com [IPv6:2001:418:3fd::19]) by mailhost.m5p.com (8.14.4/8.14.4) with ESMTP id pBDB4ZAC095106 for ; Tue, 13 Dec 2011 06:04:41 -0500 (EST) (envelope-from george+freebsd@m5p.com) Message-ID: <4EE73143.5090100@m5p.com> Date: Tue, 13 Dec 2011 06:04:35 -0500 From: George Mitchell User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:8.0) Gecko/20111127 Thunderbird/8.0 MIME-Version: 1.0 To: freebsd-stable@freebsd.org References: <4EE1EAFE.3070408@m5p.com> <4EE22421.9060707@gmail.com> <4EE6060D.5060201@mail.zedat.fu-berlin.de> <20111212155159.GB73597@troutmask.apl.washington.edu> <4EE6295B.3020308@cran.org.uk> In-Reply-To: <4EE6295B.3020308@cran.org.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.2.7 (mailhost.m5p.com [IPv6:2001:418:3fd::f7]); Tue, 13 Dec 2011 06:04:41 -0500 (EST) X-Scanned-By: MIMEDefang 2.72 on IPv6:2001:418:3fd::f7 Subject: Re: SCHED_ULE should not be the default X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Dec 2011 11:04:42 -0000 On 12/12/11 11:18, Bruce Cran wrote: > On 12/12/2011 15:51, Steve Kargl wrote: >> This comes up every 9 months or so, and must be approaching FAQ >> status. In a HPC environment, I recommend 4BSD. Depending on the >> workload, ULE can cause a severe increase in turn around time when >> doing already long computations. If you have an MPI application, >> simply launching greater than ncpu+1 jobs can show the problem. PS: >> search the list archives for "kargl and ULE". > > This isn't something that can be fixed by tuning ULE? For example for > desktop applications kern.sched.preempt_thresh should be set to 224 from > its default. I'm wondering if the installer should ask people what the > typical use will be, and tune the scheduler appropriately. > I tried my "make buildkernel" test with "dnetc" running after setting kern.sched.preempt_thresh set to 224. It did far worse than before, getting only as far as compiling bxe overnight (compared to getting to netgragh with the default kern.sched.preempt_thresh setting). -- George Mitchell