From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: [Lsf10-pc] [ATTEND] Want to attend LSF 2010 Date: Thu, 1 Jul 2010 14:40:43 -0400 Message-ID: <20100701184043.GK3039@think> References: <20100701180430.GD2705@redhat.com> <4C2CD9FE.8060707@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from rcsinet10.oracle.com ([148.87.113.121]:20074 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757884Ab0GASmE (ORCPT ); Thu, 1 Jul 2010 14:42:04 -0400 Content-Disposition: inline In-Reply-To: <4C2CD9FE.8060707@redhat.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Ric Wheeler Cc: Vivek Goyal , James Bottomley , lsf10-pc@lists.linuxfoundation.org, linux-scsi@vger.kernel.org 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. -chris