From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261451AbVFMKCs (ORCPT ); Mon, 13 Jun 2005 06:02:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261455AbVFMKCq (ORCPT ); Mon, 13 Jun 2005 06:02:46 -0400 Received: from smtp200.mail.sc5.yahoo.com ([216.136.130.125]:44633 "HELO smtp200.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S261451AbVFMKC1 (ORCPT ); Mon, 13 Jun 2005 06:02:27 -0400 Message-ID: <42AD59A9.3030404@yahoo.com.au> Date: Mon, 13 Jun 2005 20:02:17 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.6) Gecko/20050324 Debian/1.7.6-1 X-Accept-Language: en MIME-Version: 1.0 To: Con Kolivas CC: linux-kernel@vger.kernel.org Subject: Re: [RFC] blkstat References: <42AD55FA.50109@yahoo.com.au> <200506131954.45361.kernel@kolivas.org> In-Reply-To: <200506131954.45361.kernel@kolivas.org> 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 Con Kolivas wrote: > On Mon, 13 Jun 2005 19:46, Nick Piggin wrote: >>Oh, and before I go further, does anyone know of any program >>or statistic that allows the same functionality? Any comments? > > > Would something like iostat give similar results? > The problem with that is that it does not give you a % idle figure on the block device, so you basically can't see if the device is becoming a bottleneck. You can kind of guess if you take into account the seeks, and the throughput, but you're still missing things like head position (eg. changes throughput), settle time and rotational latency, and lots of other stuff. Thanks, Nick Also, BTW. the way I have done the kernel patch make a device show 100% utilisation even if it is not doing anything but waiting for a plug, or an anticipatory scheduler. This is basically all the end user wants to know, although for development purposes it may be interesting to know the other metric too. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com