Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755275AbYGSW1h (ORCPT ); Sat, 19 Jul 2008 18:27:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753382AbYGSW12 (ORCPT ); Sat, 19 Jul 2008 18:27:28 -0400 Received: from wf-out-1314.google.com ([209.85.200.172]:58346 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752273AbYGSW11 (ORCPT ); Sat, 19 Jul 2008 18:27:27 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=nzzaUMqgybR8nJyiITdE6MV/xzpSYv3kYK4AZPPsSTEJ2CP0h2uXi8JS55sA/JCBya 4q6JnG+9UAxfVacidDqdw0AZYfTvZLTke3wSuSRHoFPU+uuz90xMd2gKcyn6wrSDXt1D k0J6jUV6KU2LSiHdX3iiFl7ITkCnGCt+xxYdA= Message-ID: <19f34abd0807191527u61c5ed61kffe2279c8d46915d@mail.gmail.com> Date: Sun, 20 Jul 2008 00:27:26 +0200 From: "Vegard Nossum" To: "Greg KH" Subject: Re: linux-next: Tree for July 18: warning at kernel/lockdep.c:2068 trace_hardirqs_on_caller Cc: "Mariusz Kozlowski" , "Dave Hansen" , "Stephen Rothwell" , kernel-testers@vger.kernel.org, linux-next@vger.kernel.org, LKML , "Pekka Enberg" In-Reply-To: <20080719221723.GB5578@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080718195352.e562a00f.sfr@canb.auug.org.au> <200807190928.33978.m.kozlowski@tuxland.pl> <19f34abd0807190255x304173d4wf2bfabb2d5bce511@mail.gmail.com> <19f34abd0807190559y2fe5ebf9h7095793e82de3122@mail.gmail.com> <20080719221723.GB5578@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2176 Lines: 56 On Sun, Jul 20, 2008 at 12:17 AM, Greg KH wrote: > On Sat, Jul 19, 2008 at 02:59:12PM +0200, Vegard Nossum wrote: >> On Sat, Jul 19, 2008 at 11:55 AM, Vegard Nossum wrote: >> > What I don't get here is how SLUB can be used this early in the boot >> > process. Notice that this is still miles away from the >> > >> > SLUB: Genslabs=12, HWalign=128, Order=0-3, MinObjects=0, CPUs=1, Nodes=1 >> > >> > line, which comes much later. And that kobject_init() _is_ calling >> > kzalloc() via verify_dynamic_kobject_allocation(). Isn't this an >> > error? >> > >> > (Unfortunately, my "git log" doesn't turn up any recent changes for >> > any of the affected code paths here.) >> >> Ehe... and this is the reason why: The code was added by this patch: >> >> commit 0e3638d1e04040121af00195f7e4628078246489 >> Author: Dave Hansen >> Date: Thu Mar 16 17:30:16 2006 -0800 >> >> warn when statically-allocated kobjects are used >> >> ..which only exists in -next. Is that just a truly ancient patch, or >> did somebody forget to adjust their clock? > > It is truely a very old patch, that only lives in my tree, and currently > isn't planned to go to Linus any year soon. > > But it has a very long history of living in the -mm tree, and finding > real bugs, it's just not "safe" enough to go to Linus's tree. Unless > you think it is? Hm. In this case, the patch is not even reporting a problem, it is in fact in error itself. The problem is that it calls kzalloc() before the slab caches have been set up. (Yes, it's a wonder that nothing crashed.) I can only suggest the addendum if (!slab_is_available()) return; Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036 -- 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/