Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757084AbZCOJrt (ORCPT ); Sun, 15 Mar 2009 05:47:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753399AbZCOJrj (ORCPT ); Sun, 15 Mar 2009 05:47:39 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:40073 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752767AbZCOJri (ORCPT ); Sun, 15 Mar 2009 05:47:38 -0400 Date: Sun, 15 Mar 2009 10:47:04 +0100 From: Ingo Molnar To: Nick Piggin , Thomas Gleixner Cc: linux-tip-commits@vger.kernel.org, Nick Piggin , Peter Zijlstra , Pekka Enberg , Matt Mackall , linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com Subject: Re: SLOB lockup (was: Re: [tip:core/locking] lockdep: annotate reclaim context (__GFP_NOFS), fix SLOB) Message-ID: <20090315094704.GA21169@elte.hu> References: <20090128135457.350751756@chello.nl> <20090315064818.GA1193@elte.hu> <200903152006.21160.nickpiggin@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200903152006.21160.nickpiggin@yahoo.com.au> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean 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=3.2.3 -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: 1137 Lines: 32 * Nick Piggin wrote: > On Sunday 15 March 2009 17:48:18 Ingo Molnar wrote: > > > > Cc: Nick Piggin > > > Cc: Peter Zijlstra > > > LKML-Reference: <20090128135457.350751756@chello.nl> > > > Signed-off-by: Ingo Molnar > > > > and with this fixed, and with SLOB now being tested in -tip, the > > new lockdep assert attached below (followed by a real lockup) > > pops up. > > > > Seems like a genuine SLOB bug, probably present upstream as > > well. > > Hmmf. debugobjects calls back into the slab allocator from the > page allocator. The following patch would improve SLOB, but I > think it would be a good idea to avoid a dependency in that > direction. Can debugobjects defer this freeing? dunno - that's a question for Thomas. this lockup does not trigger under any of the other allocators. 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/