Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755326AbZJNR7f (ORCPT ); Wed, 14 Oct 2009 13:59:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751771AbZJNR7e (ORCPT ); Wed, 14 Oct 2009 13:59:34 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:48149 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751457AbZJNR7d (ORCPT ); Wed, 14 Oct 2009 13:59:33 -0400 Date: Wed, 14 Oct 2009 19:58:46 +0200 From: Ingo Molnar To: Alan Cox Cc: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, gregkh@suse.de, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:bkl/drivers] drivers: Remove BKL from misc_open Message-ID: <20091014175846.GA3537@elte.hu> References: <20091010153349.237173041@linutronix.de> <20091014171249.57dcdcfc@lxorguk.ukuu.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091014171249.57dcdcfc@lxorguk.ukuu.org.uk> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1240 Lines: 36 * Alan Cox wrote: > On Wed, 14 Oct 2009 15:47:39 GMT > tip-bot for Thomas Gleixner wrote: > > > Commit-ID: 40b798efe3460797a4ac928ee2e038774e2758eb > > Gitweb: http://git.kernel.org/tip/40b798efe3460797a4ac928ee2e038774e2758eb > > Author: Thomas Gleixner > > AuthorDate: Sat, 10 Oct 2009 15:35:43 +0000 > > Committer: Thomas Gleixner > > CommitDate: Wed, 14 Oct 2009 17:33:32 +0200 > > > > drivers: Remove BKL from misc_open > > > > misc_open() is already serialized with misc_mtx. Remove the BKL > > locking which got there via the BKL pushdown. > > NAK. > > You can't simply assume the mutex is enough - you have to either push > it down or review *every* possible called point below the lock_kernel > take. > > In this case the open method of the misc devices below sometimes uses > the BKL. We did that and it's safe in nvram.c. If you know an unsafe please let us know. Ingo -- 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/