From owner-freebsd-stable@FreeBSD.ORG Mon Dec 12 16:18:39 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 54E8A1065673; Mon, 12 Dec 2011 16:18:39 +0000 (UTC) (envelope-from bruce@cran.org.uk) Received: from muon.cran.org.uk (muon.cran.org.uk [IPv6:2a01:348:0:15:5d59:5c40:0:1]) by mx1.freebsd.org (Postfix) with ESMTP id AA9AB8FC18; Mon, 12 Dec 2011 16:18:38 +0000 (UTC) Received: from muon.cran.org.uk (localhost [127.0.0.1]) by muon.cran.org.uk (Postfix) with ESMTP id C9CE3E6208; Mon, 12 Dec 2011 16:18:36 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=cran.org.uk; h=message-id :date:from:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; s=mail; bh=Q9z1bk1qmKZA XQ8nRStBeMc3/Jk=; b=SxXMh7kUdQYpi15Kt2J0Rs6fYC1olhC17WIs0zDjIT5D A1Iq96vlmLVpcO1A6qoh99oVO5W12+/fCMZtP1D+efVwW3aBMFT4sZTaoXUOlFDh rGWM1gOuR1TCFVUlHquestEdOYF2nPQGwZnksQNhdP74MsDVCh/kWz9Ns5moGS4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=cran.org.uk; h=message-id :date:from:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; q=dns; s=mail; b=RcWMeC 1y8njc525uJc8U1Tmzb2xH95iBdBPjvx9fu+qY8W+IegM0A5JKq62k7OQUsNg5df YhaIreE02yvjKlB4ycT5fpwQ1N+QZPLK56mfkiGjFav7JnbvhQh6Fy5NrFdv/ULi t+KDjFXsZ1d3YNfJatjra7CllK0LWd/TQoKCk= Received: from [192.168.1.120] (188-220-36-32.zone11.bethere.co.uk [188.220.36.32]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by muon.cran.org.uk (Postfix) with ESMTPSA id 50421E6200; Mon, 12 Dec 2011 16:18:36 +0000 (GMT) Message-ID: <4EE6295B.3020308@cran.org.uk> Date: Mon, 12 Dec 2011 16:18:35 +0000 From: Bruce Cran User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: Steve Kargl References: <4EE1EAFE.3070408@m5p.com> <4EE22421.9060707@gmail.com> <4EE6060D.5060201@mail.zedat.fu-berlin.de> <20111212155159.GB73597@troutmask.apl.washington.edu> In-Reply-To: <20111212155159.GB73597@troutmask.apl.washington.edu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "O. Hartmann" , Current FreeBSD , freebsd-stable@freebsd.org, freebsd-performance@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 16:18:39 -0000 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. -- Bruce Cran