From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753237AbZCTEQf (ORCPT ); Fri, 20 Mar 2009 00:16:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750820AbZCTEQY (ORCPT ); Fri, 20 Mar 2009 00:16:24 -0400 Received: from g5t0007.atlanta.hp.com ([15.192.0.44]:47939 "EHLO g5t0007.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750703AbZCTEQX (ORCPT ); Fri, 20 Mar 2009 00:16:23 -0400 Date: Thu, 19 Mar 2009 22:15:00 -0600 From: Alex Chiang To: Kenji Kaneshige Cc: jbarnes@virtuousgeek.org, shimada-yxb@necst.nec.co.jp, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 00/12] PCI core learns hotplug Message-ID: <20090320041500.GB26595@ldl.fc.hp.com> References: <20090318222426.887.1008.stgit@bob.kio> <49C1FE8A.9000401@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49C1FE8A.9000401@jp.fujitsu.com> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Kenji Kaneshige : > Alex Chiang wrote: >> We're getting close to the new merge window, and I _think_ this >> patch series is ready for consideration. Notably: >> >> - multiple rescans/removes of devices with and without bridges >> - verified that resource allocation after multiple remove/rescan >> cycles is the same as what we had during initial boot >> - fixes the complete suckage of fakephp (that I created) >> - doesn't affect existing hotplug drivers >> - tested on x86 and ia64 platforms >> >> Please review, and consider testing. For testing ease, you can pull >> from my git branch: >> >> git://git.kernel.org/pub/scm/linux/kernel/git/achiang/pci-hotplug.git >> branch 'test-20090318' is what you want >> > > I got the following oops when I did > > # echo 1 > remove > > on the bridge device. > > [ 6639.239164] ============================================= > [ 6639.239191] [ INFO: possible recursive locking detected ] > [ 6639.239212] 2.6.29-rc8-kk #1 > [ 6639.239227] --------------------------------------------- > [ 6639.239243] events/8/60 is trying to acquire lock: > [ 6639.239252] (events){--..}, at: [] flush_workqueue+0x0/0xa0 > [ 6639.239252] > [ 6639.239252] but task is already holding lock: > [ 6639.239252] (events){--..}, at: [] run_workqueue+0x108/0x230 > [ 6639.239252] > [ 6639.239252] other info that might help us debug this: > [ 6639.239252] 3 locks held by events/8/60: > [ 6639.239252] #0: (events){--..}, at: [] run_workqueue+0x108/0x230 > [ 6639.239252] #1: (&ss->work){--..}, at: [] run_workqueue+0x108/0x230 > [ 6639.239252] #2: (pci_remove_rescan_mutex){--..}, at: [] remove_callback+0x29/0x80 > [ 6639.239252] > [ 6639.239252] stack backtrace: > [ 6639.239252] Pid: 60, comm: events/8 Not tainted 2.6.29-rc8-kk #1 > [ 6639.239252] Call Trace: > [ 6639.239252] [] validate_chain+0xb7d/0x1260 > [ 6639.239252] [] __lock_acquire+0x42e/0xa40 > [ 6639.239252] [] lock_acquire+0x58/0x80 > [ 6639.239252] [] ? flush_workqueue+0x0/0xa0 > [ 6639.239252] [] flush_workqueue+0x4d/0xa0 > [ 6639.239252] [] ? flush_workqueue+0x0/0xa0 > [ 6639.239252] [] flush_scheduled_work+0x10/0x20 > [ 6639.239252] [] e1000_remove+0x55/0xfe [e1000e] > [ 6639.239252] [] ? sysfs_schedule_callback_work+0x0/0x50 > [ 6639.239252] [] pci_device_remove+0x32/0x70 > [ 6639.239252] [] __device_release_driver+0x59/0x90 > [ 6639.241006] [] device_release_driver+0x2b/0x40 > [ 6639.241006] [] bus_remove_device+0xa6/0x120 > [ 6639.241006] [] device_del+0x12b/0x190 > [ 6639.241006] [] device_unregister+0x26/0x70 > [ 6639.241006] [] pci_stop_dev+0x49/0x60 > [ 6639.241006] [] pci_remove_bus_device+0x40/0xc0 > [ 6639.241006] [] pci_remove_behind_bridge+0x2d/0x50 > [ 6639.241006] [] pci_remove_bus_device+0x1e/0xc0 > [ 6639.241006] [] remove_callback+0x38/0x80 > [ 6639.241006] [] sysfs_schedule_callback_work+0x1f/0x50 > [ 6639.241006] [] run_workqueue+0x15a/0x230 > [ 6639.241006] [] ? run_workqueue+0x108/0x230 > [ 6639.241006] [] worker_thread+0x9f/0x100 > [ 6639.241006] [] ? autoremove_wake_function+0x0/0x40 > [ 6639.241006] [] ? worker_thread+0x0/0x100 > [ 6639.241006] [] kthread+0x4d/0x80 > [ 6639.241006] [] child_rip+0xa/0x20 > [ 6639.241006] [] ? restore_args+0x0/0x30 > [ 6639.241006] [] ? kthread+0x0/0x80 > [ 6639.241006] [] ? child_rip+0x0/0x20 > [ 6639.283330] e1000e 0000:40:00.0: PCI INT A disabled > [ 6639.324332] e1000e 0000:40:00.1: PCI INT B disabled > [ 6639.325031] aer 0000:2f:04.0:pcie22: unloading service driver aer pci_device_remove() calls the driver's ->remove method directly; it shouldn't be messing around with that sysfs callback. Does this only happen with e1000e devices? Or does it happen on any bridge device? I am stumped; I've never seen this locking issue before... Will continue to look, thanks. /ac