Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754254Ab1DUOjY (ORCPT ); Thu, 21 Apr 2011 10:39:24 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:42874 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753863Ab1DUOjX (ORCPT ); Thu, 21 Apr 2011 10:39:23 -0400 MIME-Version: 1.0 In-Reply-To: <5F35AAD2-8277-44BD-86B6-B1D7B816071E@kernel.dk> References: <20110420125824.GA3507@tiehlicka.suse.cz> <4DAEDBEB.7060904@fusionio.com> <20110420132903.GA13554@tiehlicka.suse.cz> <4DAF18DF.9080205@fusionio.com> <20110421071642.GA3556@tiehlicka.suse.cz> <5F35AAD2-8277-44BD-86B6-B1D7B816071E@kernel.dk> From: Linus Torvalds Date: Thu, 21 Apr 2011 07:38:57 -0700 Message-ID: Subject: Re: 2.6.39-rc4 BUG: unable to handle kernel NULL pointer dereference at 0000000c IP: cfq_insert_request+0x1d/0x3f5 To: Jens Axboe Cc: Michal Hocko , Jens Axboe , LKML 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 Content-Length: 708 Lines: 19 On Thu, Apr 21, 2011 at 12:25 AM, Jens Axboe wrote: >> >> I am going to bisect, let's see if I can find anything. > > Thanks, that would be great! I'd expect it to be very timing-dependent, and thus could easily be triggered (or hidden) by unrelated changes. Just happening to have a request added to the elevator at _just_ the same moment that another CPU is changing it and getting rid of the data structures for the old one. Linus -- 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/