Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753069AbYAXNhn (ORCPT ); Thu, 24 Jan 2008 08:37:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751793AbYAXNgx (ORCPT ); Thu, 24 Jan 2008 08:36:53 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:58653 "EHLO amd.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751608AbYAXNgw (ORCPT ); Thu, 24 Jan 2008 08:36:52 -0500 Date: Thu, 24 Jan 2008 11:35:50 +0100 From: Pavel Machek To: Mathieu Desnoyers Cc: Daniel Walker , Steven Rostedt , LKML , Ingo Molnar , Linus Torvalds , Andrew Morton , Peter Zijlstra , Christoph Hellwig , Gregory Haskins , Arnaldo Carvalho de Melo , Thomas Gleixner , Tim Bird , Sam Ravnborg , "Frank Ch. Eigler" , Jan Kiszka , John Stultz , Arjan van de Ven , Steven Rostedt Subject: Re: [PATCH 01/20 -v5] printk - dont wakeup klogd with interrupts disabled Message-ID: <20080124103550.GA3433@elf.ucw.cz> References: <20080123160236.969334052@goodmis.org> <20080123160441.236562634@goodmis.org> <1201107978.13596.16.camel@imap.mvista.com> <20080123172509.GC22229@Krystal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080123172509.GC22229@Krystal> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1449 Lines: 39 On Wed 2008-01-23 12:25:09, Mathieu Desnoyers wrote: > * Daniel Walker (dwalker@mvista.com) wrote: > > > > On Wed, 2008-01-23 at 11:02 -0500, Steven Rostedt wrote: > > > > > + if (!irqs_disabled() && wake_klogd) > > > wake_up_klogd(); > > > > This causes a regression .. When printk is called during an OOPS in > > kernels without this change then the OOPS will get logged, since the > > logging process (klogd) is woken to handle the messages.. If you apply > > this change klogd doesn't wakeup, and hence doesn't log the oops.. So if > > you remove the wakeup here you have to add it someplace else to maintain > > the logging .. > > > > (I'm not theorizing here, I have defects logged against this specific > > piece of code..) > > > > Can we change this for : > if (!(irqs_disabled() && !oops_in_progress) && wake_klogd) > wake_up_klogd(); > > ? That's wrong, too. Just make wake_up_klogd do trylock, if it finds that it can't get neccessary locks, printk(KERN_ALERT) so at least console gets the message, but proceed without the lock. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/