From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: IO scheduler based IO controller V10 Date: Fri, 2 Oct 2009 20:26:08 +0200 Message-ID: <20091002182608.GO31616@kernel.dk> References: <20091002145610.GD31616@kernel.dk> <20091002171129.GG31616@kernel.dk> <20091002172046.GA2376@elte.hu> <20091002172554.GJ31616@kernel.dk> <20091002172842.GA4884@elte.hu> <20091002173732.GK31616@kernel.dk> <20091002175629.GA14860@elte.hu> <20091002180437.GL31616@kernel.dk> <1254507754.8667.15.camel@marge.simson.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1254507754.8667.15.camel@marge.simson.net> Sender: linux-kernel-owner@vger.kernel.org To: Mike Galbraith Cc: Ingo Molnar , Linus Torvalds , Vivek Goyal , Ulrich Lukas , linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, dm-devel@redhat.com, nauman@google.com, dpshah@google.com, lizf@cn.fujitsu.com, mikew@google.com, fchecconi@gmail.com, paolo.valente@unimore.it, ryov@valinux.co.jp, fernando@oss.ntt.co.jp, jmoyer@redhat.com, dhaval@linux.vnet.ibm.com, balbir@linux.vnet.ibm.com, righi.andrea@gmail.com, m-ikeda@ds.jp.nec.com, agk@redhat.com, akpm@linux-foundation.org, peterz@infradead.org, jmarchan@redhat.com, riel@redhat.com List-Id: dm-devel.ids On Fri, Oct 02 2009, Mike Galbraith wrote: > On Fri, 2009-10-02 at 20:04 +0200, Jens Axboe wrote: > > > I'm not too crazy about it either. How about just using 'desktop' since > > this is obviously what we are really targetting? 'latency' isn't fully > > descriptive either, since it may not necessarily provide the best single > > IO latency (noop would). > > Grin. "Perfect is the enemy of good" :) > Avg > 16.24 175.82 154.38 228.97 147.16 144.5 noop > 43.23 57.39 96.13 148.25 180.09 105.0 deadline Yep, that's where it falls down. Noop basically fails here because it treats all IO as equal, which obviously isn't true for most people. But even for pure read workloads (is the above the mixed read/write, or just read?), latency would be excellent with noop but the desktop experience would not. -- Jens Axboe