From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759902Ab0HEIK5 (ORCPT ); Thu, 5 Aug 2010 04:10:57 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:52927 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759708Ab0HEIKz convert rfc822-to-8bit (ORCPT ); Thu, 5 Aug 2010 04:10:55 -0400 Subject: Re: lockdep and oops_in_progress From: Peter Zijlstra To: Dave Airlie Cc: Ingo Molnar , Jesse Barnes , LKML In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Thu, 05 Aug 2010 10:10:49 +0200 Message-ID: <1280995849.1923.1515.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2010-08-05 at 16:21 +1000, Dave Airlie wrote: > Hi guys, > > I was debugging a wierd issue with suspend/resume and fbcon/X with > some recent work Jesse and myself did to try and make sure a pinned > fbcon always gets the text on it with a panic or oops occurs. > > It does this by testing the oops_in_progress flag, however once any > lockdep issue occurs it looks to me that we leave this flag set > forever, in most places I can see in oops code etc they call > bust_spinlocks(1) then bust_spinlocks(0) to balance the > oops_in_progress value, but lockdep never seems to reset it. > > I'm wondering if there is an inherent reason for this or if I whip up > a patch to reset once the lockdep is printed if this would cause any > issues? That's debug_locks_off(), right? I don't think there's a particular reason we keep it set, cleaning that up might take a bit of work but shouldn't be too hard. Ingo, do you remember anything about that?, I think that bit comes from before my time.