From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753353AbYDPSsn (ORCPT ); Wed, 16 Apr 2008 14:48:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750859AbYDPSsf (ORCPT ); Wed, 16 Apr 2008 14:48:35 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:1421 "EHLO spitz.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750754AbYDPSse (ORCPT ); Wed, 16 Apr 2008 14:48:34 -0400 Date: Wed, 16 Apr 2008 20:44:41 +0200 From: Pavel Machek To: axboe@kernel.dk, linux-kernel@vger.kernel.org, paolo.valente@unimore.it Subject: Re: [RESEND][RFC] BFQ I/O Scheduler Message-ID: <20080416184441.GA3923@ucw.cz> References: <20080401152903.GB34860@gandalf.sssup.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080401152903.GB34860@gandalf.sssup.it> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 2008-04-01 17:29:03, Fabio Checconi wrote: > [sorry for reposting, wrong subject] > > Hi, > we are working to a new I/O scheduler based on CFQ, aiming at > improved predictability and fairness of the service, while maintaining > the high throughput it already provides. > > The patchset, too big for lkml posting, is available here: > http://feanor.sssup.it/~fabio/linux/bfq/patches/ > > The Budget Fair Queueing (BFQ) scheduler turns the CFQ Round-Robin > scheduling policy of time slices into a fair queueing scheduling > of sector budgets. More precisely, each task is assigned a budget > measured in number of sectors instead of amount of time, and budgets ... > In the first type of tests, to achieve a higher throughput than CFQ > (with the default 100 ms time slice), the maximum budget for BFQ > had to be set to at least 4k sectors. Using the same value for the Hmm, 4k sectors is ~40 seconds worst case, no? That's quite long... -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html