Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756202AbYBORLW (ORCPT ); Fri, 15 Feb 2008 12:11:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752154AbYBORLK (ORCPT ); Fri, 15 Feb 2008 12:11:10 -0500 Received: from threatwall.zlynx.org ([199.45.143.218]:33243 "EHLO zlynx.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751691AbYBORLI (ORCPT ); Fri, 15 Feb 2008 12:11:08 -0500 Subject: Re: Disk schedulers From: Zan Lynx To: Prakash Punnoor Cc: Jan Engelhardt , Lukas Hejtmanek , linux-kernel@vger.kernel.org In-Reply-To: <200802151557.59082.prakash@punnoor.de> References: <20080214162104.GA5347@ics.muni.cz> <200802151557.59082.prakash@punnoor.de> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-aIeDty+2jUMx7GC6E0Lj" Date: Fri, 15 Feb 2008 10:11:26 -0700 Message-Id: <1203095486.6663.12.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 X-Envelope-From: zlynx@acm.org X-Spam-Id: 20080215/1JQ45J-0004p2-IQ-linux-kernel@vger.kernel.org:zlynx@acm.org:199.45.143.218 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1521 Lines: 48 --=-aIeDty+2jUMx7GC6E0Lj Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Fri, 2008-02-15 at 15:57 +0100, Prakash Punnoor wrote: > On the day of Friday 15 February 2008 Jan Engelhardt hast written: > > On Feb 14 2008 17:21, Lukas Hejtmanek wrote: > > >Hello, > > > > > >whom should I blame about disk schedulers? > > > > Also consider > > - DMA (e.g. only UDMA2 selected) > > - aging disk >=20 > Nope, I also reported this problem _years_ ago, but till now much hasn't=20 > changed. Large writes lead to read starvation. Yes, I see this often myself. It's like the disk IO queue (I set mine to 1024) fills up, and pdflush and friends can stuff write requests into it much more quickly than any other programs can provide read requests. CFQ and ionice work very well up until iostat shows average IO queuing above 1024 (where I set the queue number). --=20 Zan Lynx --=-aIeDty+2jUMx7GC6E0Lj Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.7 (GNU/Linux) iD4DBQBHtce+G8fHaOLTWwgRAjmfAJdDk9RuzmukPm00vgc8a2Dk8hy8AJ46GBp3 wQ4kH35/1cp8cIujlnURZA== =GD0e -----END PGP SIGNATURE----- --=-aIeDty+2jUMx7GC6E0Lj-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/