Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760057AbZA3BUi (ORCPT ); Thu, 29 Jan 2009 20:20:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754669AbZA3BUa (ORCPT ); Thu, 29 Jan 2009 20:20:30 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:56693 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754525AbZA3BU3 (ORCPT ); Thu, 29 Jan 2009 20:20:29 -0500 Date: Thu, 29 Jan 2009 17:20:10 -0800 From: Andrew Morton To: Dave Airlie Cc: kerolasa@gmail.com, kerolasa@iki.fi, linux-kernel@vger.kernel.org, dri-devel@lists.sourceforge.net, Dave Airlie , Laurent Pinchart Subject: Re: PROBLEM: kernel BUG at drivers/gpu/drm/drm_fops.c:146! Message-Id: <20090129172010.f25fe0ad.akpm@linux-foundation.org> In-Reply-To: <21d7e9970901291706t17fc3d9aq753f90db75396639@mail.gmail.com> References: <20090129163032.f97901c5.akpm@linux-foundation.org> <21d7e9970901291706t17fc3d9aq753f90db75396639@mail.gmail.com> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2159 Lines: 52 On Fri, 30 Jan 2009 11:06:47 +1000 Dave Airlie wrote: > On Fri, Jan 30, 2009 at 10:30 AM, Andrew Morton > wrote: > > (cc's added) > > > > On Wed, 21 Jan 2009 13:27:48 +0100 > > Sami Kerola wrote: > > > >> I compiled the Torvalds git kernel 2.6.29-rc2-00013 and I got an oops. > >> The oops happens when ever X starts. Initially I was booting with run > >> level 5 and it hung. I tried to use run level to 3 and an operating > >> system started just fine. When I type startx the hung happen again. > >> Please let me know if you need some more information besides oops from > >> messages file and lspci output. > >> > >> > >> Jan 21 08:53:58 lelux kernel: ------------[ cut here ]------------ > >> Jan 21 08:53:58 lelux kernel: kernel BUG at drivers/gpu/drm/drm_fops.c:146! > > > > I assume that 2.6.28 didn't do this? > > This is a userspace race between udev and libdrm, I'm not sure we can do > anything in the kernel other than BUG, maybe we should just WARN instead. > > Basically, libdrm creates devices nodes, the initial drm opening gets that, udev > comes along when the module is loaded and re-creates the device node, > when AIGLX opens the device > it can't figure out wtf just happened, as the inode->i_mapping we use > to store the GEM device mmap ranges is different. > > I think building libdrm with --enable-udev is the correct answer, and > maybe switching this to a WARN so it doesn't blow up. > > maybe we shouldn't be storing the inode mapping like this? anyone any > better idea? > hm, I'm a bit surprised to see the drm code using `struct address_space' and read_mapping_page() and unmap_mapping_range() and such. I thought those only worked with regular files and pagecache :) Is it possible to briefly explain what's going on there? What instance of address_space_operations does ->dev_mapping actually point at? -- 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/