From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752061AbbE1DpY (ORCPT ); Wed, 27 May 2015 23:45:24 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39488 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751659AbbE1DpV (ORCPT ); Wed, 27 May 2015 23:45:21 -0400 Date: Thu, 28 May 2015 13:45:11 +1000 From: NeilBrown To: Jens Axboe Cc: Keith Busch , lkml Subject: Re: LOCKDEP warning due to ext_devt_lock Message-ID: <20150528134511.27f9bdbc@notabene.brown> In-Reply-To: <55668C45.3060700@fb.com> References: <20150528123233.3df8ff55@notabene.brown> <55668C45.3060700@fb.com> X-Mailer: Claws Mail 3.10.1-162-g4d0ed6 (GTK+ 2.24.25; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/K0cQLDFRwoeT9C9kcbxMiSw"; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Sig_/K0cQLDFRwoeT9C9kcbxMiSw Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Wed, 27 May 2015 21:32:21 -0600 Jens Axboe wrote: > On 05/27/2015 08:32 PM, NeilBrown wrote: > > > > Hi Keith, > > I'm getting lockdep warning around use of ext_devt_lock. > > > > [11428.266019] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. > > > > As you say in > > 2da78092dda1 ("block: Fix dev_t minor allocation lifetime") > > ext_devt_lock can be taken from call_rcu's soft-irq. > > I think that means it should always use the _irq verion of spinlock. >=20 > Wouldn't spin_lock_bh() and friends suffice then? >=20 Quite possibly. I've never actually used those so I don't tend to think about them. But only reflection I think they would be exactly right. I'll modify my patch for future testing. BTW, did you get my: [PATCH v2] block: discard bdi_unregister() in favour of bdi_destroy() ?? I haven't seen it appear in your 'block' tree. Thanks, NeilBrown --Sig_/K0cQLDFRwoeT9C9kcbxMiSw Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIVAwUBVWaPSDnsnt1WYoG5AQIi2BAAta2QzJG0k6CnECMI9+aJGfX/lxs/+y0c 6isS7FMHYGVaE49oA+T14YPnzwUHVshHF0I456qgXITR+uCE63tc9SAp9KjnCrle pT8OgKh7V2CgeL03Wn2eT6zACPKIUrKMwmczCRDeCNyPdaeehy5P7EquF3ta4kPh MIAUEbFlwYZ4qxYa8kDekk+Wz23LYlDxwpyti46g/nH7q4n9SYXruoXZhrZoZMN8 BgWnWwZqSqcsFrMv6ewUvsXaDqiz/1oLY7FcHDH7wq9zrDMXVFT/Y2M6YAhbSbfQ YXNOKDPSpgka+WHHqWqBWhob2GYLQNaatDFi/LtlSowiKcurdr+KLh9qDccBiJB2 /XXMCUDhaUxHMdfD8I1lDfSiWSOQJXCZYuAx6UUMrCUQPwG0A2oG/81hj1G4RZuM +nbKQwl2/azECPCIE4Mor8Ukvai5w9K4QYzz8XBBmTaaNw0BWXJndKf5Kc6oj+KM wI9N9CzHg/MwzO09kImD8HqOf0OXnjwtNimxP3CjQDAXoR6Gj7mMErff2spaaHr3 FfDTrTTgFjVr3T2ztVy9q5tHxEgBndiLPQu6vPMwYReTBCX2p7OMUEQo1rykFf/p AYIfvmI1Tf7o2wIcoHvHYopE7mvO9qs3mvvbGkDVJkAC45YkvO9OSoh5YPHQ4eDb ju0y2ymikiU= =cgDf -----END PGP SIGNATURE----- --Sig_/K0cQLDFRwoeT9C9kcbxMiSw--