From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270272AbTGMQbh (ORCPT ); Sun, 13 Jul 2003 12:31:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270273AbTGMQbg (ORCPT ); Sun, 13 Jul 2003 12:31:36 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:13746 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S270272AbTGMQb3 (ORCPT ); Sun, 13 Jul 2003 12:31:29 -0400 Message-ID: <3F118CC6.9080906@pobox.com> Date: Sun, 13 Jul 2003 12:45:58 -0400 From: Jeff Garzik Organization: none User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20021213 Debian/1.2.1-2.bunk X-Accept-Language: en MIME-Version: 1.0 To: Chris Mason CC: Jens Axboe , Marcelo Tosatti , lkml , "Stephen C. Tweedie" , Alan Cox , Andrew Morton , Andrea Arcangeli , Alexander Viro Subject: Re: RFC on io-stalls patch References: <20030710135747.GT825@suse.de> <1057932804.13313.58.camel@tiny.suse.com> <20030712073710.GK843@suse.de> <1058034751.13318.95.camel@tiny.suse.com> <20030713090116.GU843@suse.de> <1058113238.13313.127.camel@tiny.suse.com> In-Reply-To: <1058113238.13313.127.camel@tiny.suse.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Chris Mason wrote: > Well, I'd say it's a more common problem to have lots of writes, but it > is pretty easy to fill the queue with reads. Well.... * you will usually have more reads than writes * reads are more dependent than writes, on the whole * writes are larger due to delays and merging All this is obviously workload dependent, but it seems like the 60% common case, at least... Basically when I hear people talking about lots of writes, that seems to be downplaying the fact that seeing 20 writes and 2 reads on a queue does not take into account the userspace applications currently blocking, waiting to do another read. Jeff