From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756654AbaD1UNK (ORCPT ); Mon, 28 Apr 2014 16:13:10 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39333 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756320AbaD1UNI (ORCPT ); Mon, 28 Apr 2014 16:13:08 -0400 Date: Mon, 28 Apr 2014 22:13:05 +0200 From: Jan Kara To: Steven Rostedt Cc: Jan Kara , Peter Zijlstra , "Shevchenko, Andriy" , Andrew Morton , "linux-kernel@vger.kernel.org" , Ingo Molnar Subject: Re: lockdep warning after recent cleanup in console code Message-ID: <20140428201305.GG9091@quack.suse.cz> References: <1398702925.11914.292.camel@smile.fi.intel.com> <20140428134331.68771bf7@gandalf.local.home> <20140428175139.GD9091@quack.suse.cz> <20140428141439.3580dce9@gandalf.local.home> <20140428192416.GE9091@quack.suse.cz> <20140428153642.413ec8e8@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140428153642.413ec8e8@gandalf.local.home> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 28-04-14 15:36:42, Steven Rostedt wrote: > On Mon, 28 Apr 2014 21:24:16 +0200 > Jan Kara wrote: > > > > So I had a look and we are missing mutex_release() in > > console_trylock_for_printk() if we don't have a console to print to. > > Attached patch should fix the problem. > > > > Note, your patch changes the logic a bit. It causes the > mutex_acquire(&console_lock_dep_map) to happen on console_suspend, > which the original code never did. Yes, I know. That's actually intentional and also fixes a lockdep warning - there was a separate patch doing exactly that flying around because otherwise when you suspend-resume & CPU hotplug, lockdep complains because of some cpu hotplug locks. Maybe I should note that in a changelog. Honza -- Jan Kara SUSE Labs, CR