From owner-freebsd-current@FreeBSD.ORG Mon Dec 12 16:14:03 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 75D9C106564A; Mon, 12 Dec 2011 16:14:03 +0000 (UTC) (envelope-from lars.engels@0x20.net) Received: from mail.0x20.net (mail.0x20.net [IPv6:2001:aa8:fffb:1::3]) by mx1.freebsd.org (Postfix) with ESMTP id EA3D88FC13; Mon, 12 Dec 2011 16:14:02 +0000 (UTC) Received: from mail.0x20.net (mail.0x20.net [217.69.76.211]) by mail.0x20.net (Postfix) with ESMTP id 439316A61CD; Mon, 12 Dec 2011 17:14:02 +0100 (CET) X-Virus-Scanned: amavisd-new at mail.0x20.net Received: from mail.0x20.net ([217.69.76.211]) by mail.0x20.net (mail.0x20.net [217.69.76.211]) (amavisd-new, port 10024) with ESMTP id lhy24cgq8Rc2; Mon, 12 Dec 2011 17:14:02 +0100 (CET) Received: from [10.26.32.239] (ip-109-84-0-111.web.vodafone.de [109.84.0.111]) (Authenticated sender: lala) by mail.0x20.net (Postfix) with ESMTPA id 77B4F6A6016; Mon, 12 Dec 2011 17:13:59 +0100 (CET) References: <4EE1EAFE.3070408@m5p.com> <4EE22421.9060707@gmail.com> <4EE6060D.5060201@mail.zedat.fu-berlin.de> <20111212155159.GB73597@troutmask.apl.washington.edu> User-Agent: K-9 Mail for Android In-Reply-To: <20111212155159.GB73597@troutmask.apl.washington.edu> MIME-Version: 1.0 From: Lars Engels Date: Mon, 12 Dec 2011 17:13:08 +0100 To: Steve Kargl , "O. Hartmann" Message-ID: <158db475-0d35-4ff2-a101-cf056bdfcab8@email.android.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-performance@freebsd.org, Current FreeBSD , freebsd-stable@freebsd.org Subject: Re: SCHED_ULE should not be the default X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 Dec 2011 16:14:03 -0000 Would it be possible to implement a mechanism that lets one change the scheduler on the fly? Afaik Solaris can do that. _____________________________________________ Von: Steve Kargl Versendet am: Mon Dec 12 16:51:59 MEZ 2011 An: "O. Hartmann" CC: freebsd-performance@freebsd.org, Current FreeBSD , freebsd-stable@freebsd.org Betreff: Re: SCHED_ULE should not be the default 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 _____________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"