Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751432AbZKDFtJ (ORCPT ); Wed, 4 Nov 2009 00:49:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751151AbZKDFtI (ORCPT ); Wed, 4 Nov 2009 00:49:08 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:35139 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751004AbZKDFtH (ORCPT ); Wed, 4 Nov 2009 00:49:07 -0500 Date: Tue, 3 Nov 2009 21:48:45 -0800 From: Andrew Morton To: Jiri Slaby Cc: linux-kernel@vger.kernel.org, mm-commits@vger.kernel.org, Benjamin Herrenschmidt , Tiago Vignatti , Dave Airlie , kvm@vger.kernel.org, Greg KH , Kay Sievers Subject: Re: vga_arb warning [was: mmotm 2009-11-01-10-01 uploaded] Message-Id: <20091103214845.9660895d.akpm@linux-foundation.org> In-Reply-To: <4AEE01D9.8040902@gmail.com> References: <200911011807.nA1I7o95016136@imap1.linux-foundation.org> <4AEE01D9.8040902@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: 2641 Lines: 71 Please cc me on mmotm bug reports! On Sun, 01 Nov 2009 22:47:05 +0100 Jiri Slaby wrote: > On 11/01/2009 07:07 PM, akpm@linux-foundation.org wrote: > > The mm-of-the-moment snapshot 2009-11-01-10-01 has been uploaded to > > Hi, I got the following warning while booting an image in qemu-kvm: > > WARNING: at fs/attr.c:158 notify_change+0x2da/0x310() > Hardware name: > Modules linked in: > Pid: 1, comm: swapper Not tainted 2.6.32-rc5-mm1_64 #862 > Call Trace: > [] warn_slowpath_common+0x78/0xb0 > [] warn_slowpath_null+0xf/0x20 > [] notify_change+0x2da/0x310 > [] ? fsnotify_create+0x48/0x60 > [] ? vfs_mknod+0xbb/0xe0 > [] devtmpfs_create_node+0x1e6/0x270 > [] ? sysfs_addrm_finish+0x20/0x280 > [] ? __sysfs_add_one+0x26/0xf0 > [] ? sysfs_do_create_link+0xcc/0x160 > [] device_add+0x1e0/0x5b0 > [] ? pm_runtime_init+0xa1/0xb0 > [] ? device_pm_init+0x65/0x70 > [] device_register+0x19/0x20 > [] device_create_vargs+0xf0/0x120 > [] device_create+0x2c/0x30 > [] ? __register_chrdev+0x86/0xf0 > [] ? __class_create+0x69/0xa0 > [] ? mutex_lock+0x19/0x50 > [] misc_register+0x93/0x170 > [] ? vga_arb_device_init+0x0/0x77 > [] vga_arb_device_init+0x13/0x77 > [] ? vga_arb_device_init+0x0/0x77 > [] do_one_initcall+0x37/0x190 > [] kernel_init+0x172/0x1c8 > [] child_rip+0xa/0x20 > [] ? kernel_init+0x0/0x1c8 > [] ? child_rip+0x0/0x20 There's a -mm-only debug patch: http://userweb.kernel.org/~akpm/mmotm/broken-out/notify_change-callers-must-hold-i_mutex.patch --- a/fs/attr.c~notify_change-callers-must-hold-i_mutex +++ a/fs/attr.c @@ -155,6 +155,8 @@ int notify_change(struct dentry * dentry return -EPERM; } + WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex)); + now = current_fs_time(inode->i_sb); attr->ia_ctime = now; _ I forget why it was added. It looks like it's blaming the open-coded notify_change() call in devtmpfs_create_node(). -- 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/