Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752190AbaFDKYw (ORCPT ); Wed, 4 Jun 2014 06:24:52 -0400 Received: from smtp25.sms.unimo.it ([155.185.44.25]:60291 "EHLO smtp25.sms.unimo.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751728AbaFDKYu convert rfc822-to-8bit (ORCPT ); Wed, 4 Jun 2014 06:24:50 -0400 Subject: Re: BFQ speed tests [was Re: [PATCH RFC - TAKE TWO - 00/12] New version of the BFQ I/O Scheduler] Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.2\)) Content-Type: text/plain; charset=windows-1252 From: Paolo Valente In-Reply-To: <20140604100358.GA4799@amd.pavel.ucw.cz> Date: Wed, 4 Jun 2014 12:24:30 +0200 Cc: Tejun Heo , Jens Axboe , Li Zefan , Fabio Checconi , Arianna Avanzini , linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, cgroups@vger.kernel.org Content-Transfer-Encoding: 8BIT Message-Id: <4888F93F-D58D-48DD-81A6-A6D61C452D92@unimore.it> References: <20140528221929.GG1419@htj.dyndns.org> <1401354343-5527-1-git-send-email-paolo.valente@unimore.it> <20140530160712.GG24871@htj.dyndns.org> <464F6CBE-A63E-46EF-A90D-BF8450430444@unimore.it> <20140530232804.GA5057@htj.dyndns.org> <20140602111432.GA3737@amd.pavel.ucw.cz> <20140602130226.GA14654@amd.pavel.ucw.cz> <20140604100358.GA4799@amd.pavel.ucw.cz> To: Pavel Machek X-Mailer: Apple Mail (2.1878.2) UNIMORE-X-SA-Score: -2.9 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il giorno 04/giu/2014, alle ore 12:03, Pavel Machek ha scritto: > Hi! > >> Should this attempt be useless as well, I will, if you do not mind, try by asking you more details about your system and reproducing your configuration as much as I can. >> > > Try making BFQ the default scheduler. That seems to break it for me, > when selected at runtime, it looks stable. > > Anyway, here are some speed tests. Background load: > > root@duo:/data/tmp# echo cfq > /sys/block/sda/queue/scheduler > root@duo:/data/tmp# echo 3 > /proc/sys/vm/drop_caches > root@duo:/data/tmp# cat /dev/zero > delme; cat /dev/zero > delme;cat > /dev/zero > delme;cat /dev/zero > delme;cat /dev/zero > delme;cat > /dev/zero > delme > > (Machine was running out of disk space.) > > (I alternate between cfq and bfq). > > Benchmark. I chose git describe because it is part of kernel build > sometimes .. and I actually wait for that. > > pavel@duo:/data/l/linux-good$ time git describe > warning: refname 'HEAD' is ambiguous. > v3.15-rc8-144-g405dedd > > Unfortunately, results are not too good for BFQ. (Can you replicate > the results?) > > # BFQ > 10.24user 1.62system 467.02 (7m47.028s) elapsed 2.54%CPU > # CFQ > 8.55user 1.26system 69.57 (1m9.577s) elapsed 14.11%CPU > # BFQ > 11.70user 3.18system 1491.59 (24m51.599s) elapsed 0.99%CPU > # CFQ, no background load > 8.51user 0.75system 30.99 (0m30.994s) elapsed 29.91%CPU > # CFQ > 8.70user 1.36system 74.72 (1m14.720s) elapsed 13.48%CPU > Definitely bad, we are about to repeat the test ? Thanks, Paolo > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- Paolo Valente Algogroup Dipartimento di Fisica, Informatica e Matematica Via Campi, 213/B 41125 Modena - Italy homepage: http://algogroup.unimore.it/people/paolo/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/