Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756840Ab3J1PQm (ORCPT ); Mon, 28 Oct 2013 11:16:42 -0400 Received: from mail-ea0-f171.google.com ([209.85.215.171]:45409 "EHLO mail-ea0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754442Ab3J1PQl (ORCPT ); Mon, 28 Oct 2013 11:16:41 -0400 Date: Mon, 28 Oct 2013 16:16:37 +0100 From: Ingo Molnar To: Knut Petersen Cc: Linus Torvalds , Thomas Gleixner , Paul McKenney , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Greg KH , linux-kernel Subject: Re: [BUG 3.12.rc4] Oops: unable to handle kernel paging request during shutdown Message-ID: <20131028151637.GA13251@gmail.com> References: <525BD08C.2080101@t-online.de> <20131026114303.GA24067@gmail.com> <526E79A2.9080303@t-online.de> <20131028150114.GA12905@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131028150114.GA12905@gmail.com> 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 Content-Length: 1502 Lines: 50 * Ingo Molnar wrote: > > I tried that patch, together with all the kobj debug options > > enabled. With that kernel configuration I was unable to > > reproduce the problem during 500 typical workload / reboot > > cycles. Without the debug options I was able to reproduce the > > last reported panic after 91 cycles. The debug options seem to > > change timing sufficiently to mask the bug ;-( > > Could you send me the kernel config please? I got your .config off-list, thanks Knut! It has all DEBUG_OBJECT options enabled: CONFIG_DEBUG_OBJECTS=y # CONFIG_DEBUG_OBJECTS_SELFTEST is not set CONFIG_DEBUG_OBJECTS_FREE=y CONFIG_DEBUG_OBJECTS_TIMERS=y CONFIG_DEBUG_OBJECTS_WORK=y CONFIG_DEBUG_OBJECTS_RCU_HEAD=y CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER=y CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT=1 but it also has DEBUG_PAGEALLOC enabled: CONFIG_DEBUG_PAGEALLOC=y I'd suggest disabling that one - it kind of overlaps debugobjects and it will definitely be a big slowdown. I'd also suggest turning off lockdep for now: CONFIG_PROVE_LOCKING=y because we know it does not trigger any useful warning. This too should speed up things a bit. Whether this would make the crash reproducable again I don't know :-/ Thanks, 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/