Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760689AbYBBLqU (ORCPT ); Sat, 2 Feb 2008 06:46:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759607AbYBBLqD (ORCPT ); Sat, 2 Feb 2008 06:46:03 -0500 Received: from mailgw.cvut.cz ([147.32.3.235]:43580 "EHLO mailgw.cvut.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756543AbYBBLqA (ORCPT ); Sat, 2 Feb 2008 06:46:00 -0500 X-Greylist: delayed 1480 seconds by postgrey-1.27 at vger.kernel.org; Sat, 02 Feb 2008 06:46:00 EST Message-ID: <47A4522C.8090403@vc.cvut.cz> Date: Sat, 02 Feb 2008 03:21:16 -0800 From: Petr Vandrovec User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.8.1.11) Gecko/20071119 Iceape/1.1.7 (Debian-1.1.7-1) MIME-Version: 1.0 To: Linux Kernel Mailing List CC: linux-hotplug@vger.kernel.org Subject: udevd induced deadlock in loading kernel modules? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4135 Lines: 96 Mailer on sf.net says that email address in udev's README is obsolete. Oops... Petr -------- Original Message -------- Subject: udevd induced deadlock in loading kernel modules? Date: Sat, 2 Feb 2008 12:07:19 +0100 From: Petr Vandrovec To: linux-kernel@vger.kernel.org CC: linux-hotplug-devel@lists.sourceforge.net Hello, today my system hung during boot, while loading ftdi_sio & loop - I have two ftdi serial ports, and apparently this tricked udevd to start two concurrent modprobes for them - so I ended up with strance "ftdi_sio: gave up waiting for init of module usbserial." for each symbol it tried to import, until I kill-9 process 3137 (see below). After that loop got loaded, and second ftdi's load finished as well. Unfortunately I do not have stacktraces of hung modprobe processes. Maybe next time, but it does not look very reproducible. Kernel is current git (2.6.24, ed50d6cbc394cd0966469d3e249353c9dd1d38b9), udev is Debian's 0.114-2, and module-init-tools are Debian's 3.3-pre11-4. Kernel is 64bit amd64 with almost all debugging enabled, userspace is 32bit. Thanks, Petr Vandrovec usbcore: registered new interface driver usbserial /usr/src/git/libata-pv/drivers/usb/serial/usb-serial.c: USB Serial support registered for generic usbcore: registered new interface driver usbserial_generic /usr/src/git/libata-pv/drivers/usb/serial/usb-serial.c: USB Serial Driver core ftdi_sio: gave up waiting for init of module usbserial. ftdi_sio: Unknown symbol usb_serial_port_softint ftdi_sio: gave up waiting for init of module usbserial. ftdi_sio: Unknown symbol usb_serial_disconnect ftdi_sio: gave up waiting for init of module usbserial. ftdi_sio: Unknown symbol usb_serial_probe ftdi_sio: gave up waiting for init of module usbserial. ftdi_sio: Unknown symbol usb_serial_register ftdi_sio: gave up waiting for init of module usbserial. ftdi_sio: Unknown symbol usb_serial_deregister loop: module loaded /usr/src/git/libata-pv/drivers/usb/serial/usb-serial.c: USB Serial support registered for FTDI USB Serial Device ftdi_sio 4-2:1.0: FTDI USB Serial Device converter detected /usr/src/git/libata-pv/drivers/usb/serial/ftdi_sio.c: Detected FT8U232AM usb 4-2: FTDI USB Serial Device converter now attached to ttyUSB0 ftdi_sio 5-1:1.0: FTDI USB Serial Device converter detected /usr/src/git/libata-pv/drivers/usb/serial/ftdi_sio.c: Detected FT8U232AM usb 5-1: FTDI USB Serial Device converter now attached to ttyUSB1 usbcore: registered new interface driver ftdi_sio /usr/src/git/libata-pv/drivers/usb/serial/ftdi_sio.c: v1.4.3:USB FTDI Serial Converters Driver fuse init (API version 7.9) 1042 tty1 Ss+ 0:00 init boot 1045 tty1 S+ 0:00 \_ /bin/sh /etc/init.d/rc S 3954 tty1 S+ 0:00 \_ /bin/sh -e /etc/rcS.d/S20module-init-tools start 3957 tty1 S+ 0:00 \_ /bin/sh -e /etc/rcS.d/S20module-init-tools start 3958 tty1 D+ 0:00 \_ modprobe loop 1048 tty1 S+ 0:00 /bin/bash -i -m 4074 tty1 R+ 0:00 \_ ps axf 1136 ? S