From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH RFC - TAKE TWO - 00/12] New version of the BFQ I/O Scheduler Date: Wed, 4 Jun 2014 07:53:30 -0700 Message-ID: <20140604145330.GA2955@infradead.org> References: <20140531051635.GA19925@mtj.dyndns.org> <538C8A47.1050502@kernel.dk> <20140602172454.GA8912@htj.dyndns.org> <538CB515.3090700@kernel.dk> <20140602174250.GC8912@htj.dyndns.org> <538CB87C.7030600@kernel.dk> <20140602185138.GD8912@htj.dyndns.org> <20140602205713.GB8357@kernel.dk> <20140604143136.GA1920@infradead.org> <20140604145053.GE5004@htj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20140604145053.GE5004-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Tejun Heo Cc: Jens Axboe , Paolo Valente , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Christoph Hellwig , Fabio Checconi , Arianna Avanzini , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Paolo Valente On Wed, Jun 04, 2014 at 10:50:53AM -0400, Tejun Heo wrote: > Hmmm... the biggest thing is ioscheds. They heavily rely on being > strongly synchronized and are pretty important for rotating rusts. > Maybe they can be made to work with blk-mq by forcing single queue or > something but do we wnat that? Jens is planning to add an (optional) I/O scheduler to blk-mq, and that is indeed required for proper disk support. I don't think there even is a need to limit it to a single queue technically, although devices that support multiple queues are unlikely to need I/O scheduling. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752424AbaFDOxn (ORCPT ); Wed, 4 Jun 2014 10:53:43 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:55099 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752310AbaFDOxl (ORCPT ); Wed, 4 Jun 2014 10:53:41 -0400 Date: Wed, 4 Jun 2014 07:53:30 -0700 From: Christoph Hellwig To: Tejun Heo Cc: Christoph Hellwig , Jens Axboe , Paolo Valente , Li Zefan , Fabio Checconi , Arianna Avanzini , Paolo Valente , linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, cgroups@vger.kernel.org Subject: Re: [PATCH RFC - TAKE TWO - 00/12] New version of the BFQ I/O Scheduler Message-ID: <20140604145330.GA2955@infradead.org> References: <20140531051635.GA19925@mtj.dyndns.org> <538C8A47.1050502@kernel.dk> <20140602172454.GA8912@htj.dyndns.org> <538CB515.3090700@kernel.dk> <20140602174250.GC8912@htj.dyndns.org> <538CB87C.7030600@kernel.dk> <20140602185138.GD8912@htj.dyndns.org> <20140602205713.GB8357@kernel.dk> <20140604143136.GA1920@infradead.org> <20140604145053.GE5004@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140604145053.GE5004@htj.dyndns.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 04, 2014 at 10:50:53AM -0400, Tejun Heo wrote: > Hmmm... the biggest thing is ioscheds. They heavily rely on being > strongly synchronized and are pretty important for rotating rusts. > Maybe they can be made to work with blk-mq by forcing single queue or > something but do we wnat that? Jens is planning to add an (optional) I/O scheduler to blk-mq, and that is indeed required for proper disk support. I don't think there even is a need to limit it to a single queue technically, although devices that support multiple queues are unlikely to need I/O scheduling.