From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [Lsf10-pc] [ATTEND] Want to attend LSF 2010 Date: Thu, 01 Jul 2010 20:54:00 +0200 Message-ID: <4C2CE448.3010305@fusionio.com> References: <20100701180430.GD2705@redhat.com> <4C2CD9FE.8060707@redhat.com> <20100701184043.GK3039@think> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from 0122700014.0.fullrate.dk ([95.166.99.235]:40922 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757608Ab0GASyF (ORCPT ); Thu, 1 Jul 2010 14:54:05 -0400 In-Reply-To: <20100701184043.GK3039@think> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Chris Mason Cc: Ric Wheeler , James Bottomley , lsf10-pc@lists.linuxfoundation.org, linux-scsi@vger.kernel.org, Vivek Goyal On 01/07/10 20.40, Chris Mason wrote: > On Thu, Jul 01, 2010 at 02:10:06PM -0400, Ric Wheeler wrote: >> On 07/01/2010 02:04 PM, Vivek Goyal wrote: >>> Resending this mail. This time also CCing linux-scsi mailing list. Sorry >>> for the duplicate copy. >>> >>> Hi, >>> >>> I wanted to attend LSF 2010. Sepcifically I was interested in discussing >>> couple of things. >>> >>> - CFQ performance issues on higher end storage >>> - Deadline outperforms CFQ on higher end storage (storage arrays >>> and also on host based hardware RAID). I was wondering if there >>> is a way to fix it or it is just design limitation. In the past >>> Jens had mentioned that he wants to get rid of deadline also and >>> be replaced with CFQ. Are we still targeting that and if yes, >>> how to achieve that (some kind of auto tuning). >>> >>> - Max bandwidth IO controller >>> - A basic proportional weight controller (blkio) based off CFQ is >>> now in. Now there is also a need to implement throttling/max >>> bandwidth controller. Wanted to get some ideas on how to go >>> go about it and what is the best place to impement it. Implement >>> it in CFQ or a new device mapper target or something else. >>> >>> Thanks >>> Vivek >>> >> >> Thanks Vivek, >> >> I know that this IO scheduling issue has been a hot issue for us in our >> performance testing. We would love to figure out how to get CFQ to displace >> deadline totally and definitely it would be very interesting to have a >> conversation around what needs done/what can be done. >> > > I'll second that...one scheduler to rule them all. Agreed :-) -- Jens Axboe