From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754013Ab2ARBBD (ORCPT ); Tue, 17 Jan 2012 20:01:03 -0500 Received: from mail-qy0-f174.google.com ([209.85.216.174]:45469 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753852Ab2ARBBC (ORCPT ); Tue, 17 Jan 2012 20:01:02 -0500 MIME-Version: 1.0 In-Reply-To: <20120117220715.GB23527@redhat.com> References: <20120117201823.GD19223@redhat.com> <20120117214834.GD26207@google.com> <20120117220715.GB23527@redhat.com> Date: Wed, 18 Jan 2012 09:01:00 +0800 X-Google-Sender-Auth: 8xPeF0zQdlzK7qPoDBp65YKWTLg Message-ID: Subject: Re: Kernel crash in icq_free_icq_rcu From: Shaohua Li To: Vivek Goyal Cc: Tejun Heo , linux kernel mailing list , Jens Axboe Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2012/1/18 Vivek Goyal : > On Tue, Jan 17, 2012 at 01:48:34PM -0800, Tejun Heo wrote: >> On Tue, Jan 17, 2012 at 03:18:23PM -0500, Vivek Goyal wrote: >> > Hi Tejun, >> > >> > With latest linus kernel, I see following crash. I was running some >> > scripts which create cgroups and launch fio jobs in those groups. In >> > a separate window I wrote a script to change the IO scheduler on the >> > device in a loop while IO was happening on the device. After few >> > seconds I see following. So far I tried it twice and reproduced it >> > both the times in first few seconds. >> >> Does the following patch make any difference? > > Nope. Still can reproduce the issue. I had similar issue too. Looks ioc_create_icq finds an icq (in ioc_lookup_icq) the icq is in rcu free (it has __rcu_icq_cache set)