From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752730AbZHJTvj (ORCPT ); Mon, 10 Aug 2009 15:51:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751862AbZHJTvi (ORCPT ); Mon, 10 Aug 2009 15:51:38 -0400 Received: from mx2.redhat.com ([66.187.237.31]:37171 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751665AbZHJTvh (ORCPT ); Mon, 10 Aug 2009 15:51:37 -0400 Subject: Re: kmemcheck in linux-next causes NULL pointer dereference at task_rq_lock From: Eric Paris To: Vegard Nossum Cc: linux-kernel@vger.kernel.org, penberg@cs.helsinki.fi, mingo@elte.hu In-Reply-To: <19f34abd0908101156x2bc92b22ud1748abb153800fb@mail.gmail.com> References: <1249925740.2501.9.camel@dhcp231-106.rdu.redhat.com> <19f34abd0908101156x2bc92b22ud1748abb153800fb@mail.gmail.com> Content-Type: text/plain Date: Mon, 10 Aug 2009 15:51:27 -0400 Message-Id: <1249933887.2501.62.camel@dhcp231-106.rdu.redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2009-08-10 at 20:56 +0200, Vegard Nossum wrote: > 2009/8/10 Eric Paris : > > I'm using 2.6.31-rc5-next-20090810 on a vmware server. Originally I saw > > messages about setting to one cpu, so I booted with maxcpu=1. I get > > this same panic with and without maxpu. Booting with kmemcheck=0 boots > > just fine. > > > > I have not tested kmemcheck in linus' tree but will start looking for a > > working version now. Any suggestions or things I should try? > > Hi, thanks for the report, and for trying it out. > > Does it crash with "kmemcheck=0 maxcpus=1" (it should be maxcpus, not > maxcpu). This should be a simple way of determining whether it was > kmemcheck or the existing maxcpus code, which we use, that broke. I boots fine with kmemcheck=0 I did get the command line right. maxcpus=1 kmemcheck=1 was the panic I showed in the last message. > If you can send config (off-list, probably), I will try to reproduce > and investigate more tomorrow. Will send it now. Thanks. -Eric