From owner-freebsd-stable@FreeBSD.ORG Mon Dec 12 15:52:00 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 102E61065670; Mon, 12 Dec 2011 15:52:00 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (troutmask.apl.washington.edu [128.95.76.21]) by mx1.freebsd.org (Postfix) with ESMTP id C3CAA8FC12; Mon, 12 Dec 2011 15:51:59 +0000 (UTC) Received: from troutmask.apl.washington.edu (localhost.apl.washington.edu [127.0.0.1]) by troutmask.apl.washington.edu (8.14.5/8.14.5) with ESMTP id pBCFpxf6073711; Mon, 12 Dec 2011 07:51:59 -0800 (PST) (envelope-from sgk@troutmask.apl.washington.edu) Received: (from sgk@localhost) by troutmask.apl.washington.edu (8.14.5/8.14.5/Submit) id pBCFpxO9073710; Mon, 12 Dec 2011 07:51:59 -0800 (PST) (envelope-from sgk) Date: Mon, 12 Dec 2011 07:51:59 -0800 From: Steve Kargl To: "O. Hartmann" Message-ID: <20111212155159.GB73597@troutmask.apl.washington.edu> References: <4EE1EAFE.3070408@m5p.com> <4EE22421.9060707@gmail.com> <4EE6060D.5060201@mail.zedat.fu-berlin.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4EE6060D.5060201@mail.zedat.fu-berlin.de> User-Agent: Mutt/1.4.2.3i Cc: freebsd-performance@freebsd.org, Current FreeBSD , freebsd-stable@freebsd.org 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: Mon, 12 Dec 2011 15:52:00 -0000 On Mon, Dec 12, 2011 at 02:47:57PM +0100, O. Hartmann wrote: > > > Not fully right, boinc defaults to run on idprio 31 so this isn't an > > issue. And yes, there are cases where SCHED_ULE shows much better > > performance then SCHED_4BSD. [...] > > Do we have any proof at hand for such cases where SCHED_ULE performs > much better than SCHED_4BSD? Whenever the subject comes up, it is > mentioned, that SCHED_ULE has better performance on boxes with a ncpu > > 2. But in the end I see here contradictionary statements. People > complain about poor performance (especially in scientific environments), > and other give contra not being the case. > > Within our department, we developed a highly scalable code for planetary > science purposes on imagery. It utilizes present GPUs via OpenCL if > present. Otherwise it grabs as many cores as it can. > By the end of this year I'll get a new desktop box based on Intels new > Sandy Bridge-E architecture with plenty of memory. If the colleague who > developed the code is willing performing some benchmarks on the same > hardware platform, we'll benchmark bot FreeBSD 9.0/10.0 and the most > recent Suse. For FreeBSD I intent also to look for performance with both > different schedulers available. > 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". -- Steve