From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263667AbTLORtR (ORCPT ); Mon, 15 Dec 2003 12:49:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263821AbTLORtR (ORCPT ); Mon, 15 Dec 2003 12:49:17 -0500 Received: from 82-32-19-107.cable.ubr03.azte.blueyonder.co.uk ([82.32.19.107]:27803 "EHLO amphibian.dyndns.org") by vger.kernel.org with ESMTP id S263667AbTLORtO (ORCPT ); Mon, 15 Dec 2003 12:49:14 -0500 Date: Mon, 15 Dec 2003 17:49:08 +0000 To: Jeff Garzik , linux-kernel@vger.kernel.org Subject: Re: 'bad: scheduling while atomic!', preempt kernel, 2.6.1-test11, reading an apparently duff DVD-R Message-ID: <20031215174908.GA29901@amphibian.dyndns.org> References: <20031215135802.GA4332@amphibian.dyndns.org> <3FDDD923.30509@pobox.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="82I3+IH0IqGh5yIs" Content-Disposition: inline In-Reply-To: <3FDDD923.30509@pobox.com> User-Agent: Mutt/1.5.4i From: Toad Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --82I3+IH0IqGh5yIs Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Dec 15, 2003 at 10:54:11AM -0500, Jeff Garzik wrote: > Linus Torvalds wrote: > > > >On Mon, 15 Dec 2003, Toad wrote: > > > >>I got the following when trying to mount a particular DVD-R on Linux > >>2.6.0-test11, using an IDE DVD-RW drive, using SCSI emulation, with the > >>preempt kernel option enabled, and taskfile I/O: > >>(the middle bit was repeated several times): > > > > > >ide-scsi does > > > > spin_lock_irqsave(&ide_lock, flags); > > while (HWGROUP(drive)->handler) { > > HWGROUP(drive)->handler =3D NULL; > > schedule_timeout(1); > > } > > > >which is obvious crap. Scheduling while holding a spinlock is not a good > >idea. > > > >You could try dropping the lock over the schedule and re-aquire it > >afterwards, but the comment tries to say that it is required for avoiding > >new requests. > > > >This is why ide-scsi needs a maintainer, btw - somebody who cares about > >it, and actually tries to resolve the current mess. >=20 >=20 > Pardon me for asking a dumb and possibly impertinent question, but why=20 > keep it around at all? >=20 > In 2.6 it just seems like it's causing more problems than it's worth. I= =20 > mean, replacing ide-scsi with a simple 4-line driver would suffice... >=20 > int init_module(void) > { > printk(KERN_INFO "fix your app to use SG_IO\n"); > } >=20 > Since the major app, cdrecord, has already been fixed, that just leaves= =20 > a few IMO minor apps out there that (a) should be using SG IO and (b)=20 > are depending on an unmaintained and perpetually broken driver anyway. I've been completely unable to get cdrtools to compile... The version in debian is 2.0a19, which works with IDE-SCSI, and doesn't work without it. The RPM from the oss-dvd extension site doesn't work either without IDE-SCSI. Nor does dvd+rwtools. Anyone attempting to write DVDs will have real problems if IDE-SCSI is removed, judging by this experience. >=20 > Jeff >=20 >=20 > P.S. Yes, libata will probably (not definite) use the SCSI layer to=20 > drive ATAPI devices... but that's a long way off, and will not be using= =20 > the ide-scsi code. ide-scsi is basically a glue driver specifically for= =20 > drivers/ide. >=20 --=20 Matthew J Toseland - toad@amphibian.dyndns.org Freenet Project Official Codemonkey - http://freenetproject.org/ ICTHUS - Nothing is impossible. Our Boss says so. --82I3+IH0IqGh5yIs Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (GNU/Linux) iD8DBQE/3fQUr5e+zmpNTm8RAiVgAJ4wQBo240rlP6lGwB17ZK16UJvBIgCaA2SZ w1WDiUOPag7jc7H16oTzRjE= =A6pb -----END PGP SIGNATURE----- --82I3+IH0IqGh5yIs--