Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752000AbaFDKED (ORCPT ); Wed, 4 Jun 2014 06:04:03 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:59405 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751734AbaFDKEB (ORCPT ); Wed, 4 Jun 2014 06:04:01 -0400 Date: Wed, 4 Jun 2014 12:03:58 +0200 From: Pavel Machek To: Paolo Valente 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 Subject: BFQ speed tests [was Re: [PATCH RFC - TAKE TWO - 00/12] New version of the BFQ I/O Scheduler] Message-ID: <20140604100358.GA4799@amd.pavel.ucw.cz> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/