From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261456AbVFMKGA (ORCPT ); Mon, 13 Jun 2005 06:06:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261457AbVFMKF7 (ORCPT ); Mon, 13 Jun 2005 06:05:59 -0400 Received: from mail28.syd.optusnet.com.au ([211.29.133.169]:20122 "EHLO mail28.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S261456AbVFMKFo (ORCPT ); Mon, 13 Jun 2005 06:05:44 -0400 From: Con Kolivas To: Nick Piggin Subject: Re: [RFC] blkstat Date: Mon, 13 Jun 2005 20:05:38 +1000 User-Agent: KMail/1.8.1 Cc: linux-kernel@vger.kernel.org References: <42AD55FA.50109@yahoo.com.au> <200506131954.45361.kernel@kolivas.org> <42AD59A9.3030404@yahoo.com.au> In-Reply-To: <42AD59A9.3030404@yahoo.com.au> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1414827.AYvoMQYZNW"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200506132005.40846.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --nextPart1414827.AYvoMQYZNW Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Mon, 13 Jun 2005 20:02, Nick Piggin wrote: > 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. I've often wondered how iostat gives a %busy figure and whether this=20 translated accurately without further info from the kernel. > 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. That sounds quite useful. Cheers, Con --nextPart1414827.AYvoMQYZNW Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQBCrVp0ZUg7+tp6mRURAr6UAKCIUtCCN4fEsrO9FGiEc2iqQpwtVwCfV33N CeQ3+sG0Y9FzxlkKBxDSHSc= =hIv4 -----END PGP SIGNATURE----- --nextPart1414827.AYvoMQYZNW--