From owner-freebsd-stable@FreeBSD.ORG Mon Dec 12 16:48:59 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 6D3F4106567A; Mon, 12 Dec 2011 16:48:59 +0000 (UTC) (envelope-from gljennjohn@googlemail.com) Received: from mail-ee0-f54.google.com (mail-ee0-f54.google.com [74.125.83.54]) by mx1.freebsd.org (Postfix) with ESMTP id A03D38FC14; Mon, 12 Dec 2011 16:48:58 +0000 (UTC) Received: by eekc50 with SMTP id c50so3384185eek.13 for ; Mon, 12 Dec 2011 08:48:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=date:from:to:cc:subject:message-id:in-reply-to:references:reply-to :x-mailer:mime-version:content-type:content-transfer-encoding; bh=QFQyElN+lsakH/hXyvqde4RifLlcVgBZTDRMOHlFA6E=; b=L49yFzALu8AFiSjmnq5Zoxakto8S8RZJ5uihrtPrGtPlKoedDQdm0FXoIuWxq91kbJ x1fEYqXOLpCrAM4S8Kku5agZBB0aRgPTOrDIo0G9jd3liNL+dgZMrdNVsf66vaXA6D1P 2/uSipRpqUkwxpwUmlgeRdrYxltzRBNO1Yj+g= Received: by 10.14.4.154 with SMTP id 26mr2818946eej.36.1323708537575; Mon, 12 Dec 2011 08:48:57 -0800 (PST) Received: from ernst.jennejohn.org (p578E15DC.dip.t-dialin.net. [87.142.21.220]) by mx.google.com with ESMTPS id 39sm12128785eei.1.2011.12.12.08.48.55 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 12 Dec 2011 08:48:56 -0800 (PST) Date: Mon, 12 Dec 2011 17:48:54 +0100 From: Gary Jennejohn To: mdf@FreeBSD.org Message-ID: <20111212174854.4f6ea14c@ernst.jennejohn.org> In-Reply-To: References: <4EE1EAFE.3070408@m5p.com> <4EE22421.9060707@gmail.com> <4EE6060D.5060201@mail.zedat.fu-berlin.de> <4EE619FC.4000601@unsane.co.uk> <20111212163221.33d0b8a2@ernst.jennejohn.org> X-Mailer: Claws Mail 3.7.10 (GTK+ 2.24.6; amd64-portbld-freebsd10.0) Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Cc: "O. Hartmann" , Current FreeBSD , freebsd-stable@freebsd.org, freebsd-performance@freebsd.org, Vincent Hoffman Subject: Re: SCHED_ULE should not be the default X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: gljennjohn@googlemail.com 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 16:48:59 -0000 On Mon, 12 Dec 2011 08:04:37 -0800 mdf@FreeBSD.org wrote: > On Mon, Dec 12, 2011 at 7:32 AM, Gary Jennejohn > wrote: > > On Mon, 12 Dec 2011 15:13:00 +0000 > > Vincent Hoffman wrote: > > > >> > >> -----BEGIN PGP SIGNED MESSAGE----- > >> Hash: SHA1 > >> > >> On 12/12/2011 13:47, 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. > >> It all a little old now but some if the stuff in > >> http://people.freebsd.org/~kris/scaling/ > >> covers improvements that were seen. > >> > >> http://jeffr-tech.livejournal.com/5705.html > >> shows a little too, reading though Jeffs blog is worth it as it has some > >> interesting stuff on SHED_ULE. > >> > >> I thought there were some more benchmarks floating round but cant find > >> any with a quick google. > >> > >> > >> Vince > >> > >> > > >> > 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. > >> > > > > > These observations are not scientific, but I have a CPU from AMD with > > 6 cores (AMD Phenom(tm) II X6 1090T Processor). > > > > My simple test was ``make buildkernel'' while watching the core usage with > > gkrellm. > > > > With SCHED_4BSD all 6 cores are loaded to 97% during the build phase. > > I've never seen any value above 97% with gkrellm. > > > > With SCHED_ULE I never saw all 6 cores loaded this heavily.  Usually > > 2 or more cores were at or below 90%.  Not really that significant, but > > still a noticeable difference in apparent scheduling behavior.  Whether > > the observed difference is due to some change in data from the kernel to > > gkrellm is beyond me. > > SCHED_ULE is much sloppier about calculating which thread used a > timeslice -- unless the timeslice went 100% to a thread, the fraction > it used may get attributed elsewhere. So top's reporting of thread > usage is not a useful metric. Total buildworld time is, potentially. > I suspect you're right since the buildworld time, a much better test, was pretty much the same with 4BSD and ULE. -- Gary Jennejohn