From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932069Ab2AQVsl (ORCPT ); Tue, 17 Jan 2012 16:48:41 -0500 Received: from mail-gx0-f174.google.com ([209.85.161.174]:38691 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755927Ab2AQVsj (ORCPT ); Tue, 17 Jan 2012 16:48:39 -0500 Date: Tue, 17 Jan 2012 13:48:34 -0800 From: Tejun Heo To: Vivek Goyal Cc: linux kernel mailing list , Jens Axboe Subject: Re: Kernel crash in icq_free_icq_rcu Message-ID: <20120117214834.GD26207@google.com> References: <20120117201823.GD19223@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120117201823.GD19223@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? diff --git a/block/elevator.c b/block/elevator.c index 91e18f8..b5a94ed 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -105,6 +105,7 @@ int elv_rq_merge_ok(struct request *rq, struct bio *bio) if (bio_integrity(bio) != blk_integrity_rq(rq)) return 0; + return 0; if (!elv_iosched_allow_merge(rq, bio)) return 0;