From owner-freebsd-stable@FreeBSD.ORG Mon Dec 12 16:30:39 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 9E510106564A; Mon, 12 Dec 2011 16:30:38 +0000 (UTC) (envelope-from mdf356@gmail.com) Received: from mail-pz0-f54.google.com (mail-pz0-f54.google.com [209.85.210.54]) by mx1.freebsd.org (Postfix) with ESMTP id 2CB8A8FC12; Mon, 12 Dec 2011 16:30:37 +0000 (UTC) Received: by dakp5 with SMTP id p5so7144112dak.13 for ; Mon, 12 Dec 2011 08:30:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=+dryFrlmia5wNaD6PzjKbJ//sZuyakBBXiNiNL3Oq4Q=; b=lgfORXOm2V59Cfjmi+1ior8IoNtO4RvD68YAQJubbjcUkRg9uRh2blmihRprEjzK3F XXz0muY87H88yNPU+7SBGMsBVodsCdguO/hc8nhrugIpy77NclKf9Djthf3lsHR+fZeG F1lAK9kLQMEnkqQMVVhnGCN4P2Ag0+rg+6BRM= MIME-Version: 1.0 Received: by 10.68.211.5 with SMTP id my5mr36432945pbc.17.1323705877044; Mon, 12 Dec 2011 08:04:37 -0800 (PST) Sender: mdf356@gmail.com Received: by 10.68.197.198 with HTTP; Mon, 12 Dec 2011 08:04:37 -0800 (PST) In-Reply-To: <20111212163221.33d0b8a2@ernst.jennejohn.org> 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> Date: Mon, 12 Dec 2011 08:04:37 -0800 X-Google-Sender-Auth: Z-9Mf-awLdKOtIu2Ho6RiSTBpfc Message-ID: From: mdf@FreeBSD.org To: gljennjohn@googlemail.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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 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 16:30:39 -0000 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 planeta= ry >> > 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 wh= o >> > 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 bo= th >> > 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 wit= h > 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. =A0Usually > 2 or more cores were at or below 90%. =A0Not really that significant, but > still a noticeable difference in apparent scheduling behavior. =A0Whether > 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. Thanks, matthew