Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757706AbZIPPrP (ORCPT ); Wed, 16 Sep 2009 11:47:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753657AbZIPPrO (ORCPT ); Wed, 16 Sep 2009 11:47:14 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:48588 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753283AbZIPPrO (ORCPT ); Wed, 16 Sep 2009 11:47:14 -0400 Date: Wed, 16 Sep 2009 08:47:16 -0700 From: "Paul E. McKenney" To: Catalin Marinas Cc: Eric Sesterhenn , linux-kernel Subject: Re: RCU callbacks and TREE_PREEMPT_RCU Message-ID: <20090916154716.GC6737@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1253110641.31751.92.camel@pc1117.cambridge.arm.com> <20090916152929.GA6737@linux.vnet.ibm.com> <1253115255.31751.96.camel@pc1117.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1253115255.31751.96.camel@pc1117.cambridge.arm.com> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1269 Lines: 28 On Wed, Sep 16, 2009 at 04:34:15PM +0100, Catalin Marinas wrote: > On Wed, 2009-09-16 at 08:29 -0700, Paul E. McKenney wrote: > > On Wed, Sep 16, 2009 at 03:17:21PM +0100, Catalin Marinas wrote: > > > When TREE_PREEMPT_RCU is enabled, the rcu list traversing above fails > > > with access to 0x6b6b6b6b but it is fine with TREE_PREEMPT_RCU=n and > > > TREE_RCU=y. During clean-up, kmemleak objects should no longer be freed > > > by other means since kmemleak was disabled and all callbacks are > > > ignored. The system is a 900Mhz P3, 256MB RAM, CONFIG_SMP=n. > > > > > > Is there something I'm doing wrong in kmemleak or a bug with RCU > > > preemption? The kernel oops looks like this: > > > > From your description and the code above, I must suspect a bug with > > RCU preemption. A new one, as the only bugs I am currently chasing > > involve NR_CPUS>32 (>64 on 64-bit systems). > > > > CONFIG_SMP=n implies NR_CPUS==1 in your build, correct? > > CONFIG_NR_CPUS=1. I was afraid of that. ;-) Thanx, Paul -- 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/