source: udev/README.debug @ 3e15056

clfs-1.2clfs-2.1clfs-3.0.0-systemdclfs-3.0.0-sysvinitsystemdsysvinit
Last change on this file since 3e15056 was a6cd72e, checked in by Jim Gifford <clfs@…>, 18 years ago

r861@server (orig r859): jim | 2005-12-06 22:41:11 -0800

r994@server: jim | 2005-12-06 22:39:42 -0800
Updates from 077 OpenSuse? Package


  • Property mode set to 100644
File size: 2.8 KB
Line 
1Debugging the udev event processing
2===================================
3
4To visualize the driver core events and the udev event processes, use:
5  udevmonitor
6
7it prints:
8  UEVENT[1132632714.285362] add@/devices/pci0000:00/0000:00:1d.1/usb2/2-2
9  UEVENT[1132632714.288166] add@/devices/pci0000:00/0000:00:1d.1/usb2/2-2/2-2:1.0
10  UEVENT[1132632714.309485] add@/class/input/input6
11  UEVENT[1132632714.309511] add@/class/input/input6/mouse2
12  UEVENT[1132632714.309524] add@/class/usb_device/usbdev2.12
13  UDEV  [1132632714.348966] add@/devices/pci0000:00/0000:00:1d.1/usb2/2-2
14  UDEV  [1132632714.420947] add@/devices/pci0000:00/0000:00:1d.1/usb2/2-2/2-2:1.0
15  UDEV  [1132632714.427298] add@/class/input/input6
16  UDEV  [1132632714.434223] add@/class/usb_device/usbdev2.12
17  UDEV  [1132632714.439934] add@/class/input/input6/mouse2
18
19UEVENT lines show the events the kernel sends over netlink, the UDEV lines
20show the finished udev event handlers. The timing is printed in microseconds.
21The time between UEVENT and UDEV is the time udev took to process this event
22or was queued to synchronize it with other events.
23
24If called with:
25  udevmonitor --env
26
27it prints the whole event environment:
28  UDEV  [1132633002.937243] add@/class/input/input7
29  UDEV_LOG=3
30  ACTION=add
31  DEVPATH=/class/input/input7
32  SUBSYSTEM=input
33  SEQNUM=1043
34  PHYSDEVPATH=/devices/pci0000:00/0000:00:1d.1/usb2/2-2/2-2:1.0
35  PHYSDEVBUS=usb
36  PHYSDEVDRIVER=usbhid
37  PRODUCT=3/46d/c03e/2000
38  NAME="Logitech USB-PS/2 Optical Mouse"
39
40
41Udev also sends messages to syslog according to the configured debugging
42level. Udev specific tools which are called, also respect the setting
43of udev_log. But there might be some which need special actions to make
44them verbose.
45
46Set  udevs loglevel in the damon at runtime with:
47  udevcontrol log_priority=<level>
48
49Enable logging permanently, set (it may make udev _very_ slow):
50  udev_log=info in /etc/udev/udev.conf.
51
52
53For further processing of the logging output you should get a clean logfile at
54next boot. Just move the old logfile away. (Syslog will still use the moved file
55until it's restarted).
56
57The script 'show_event_log' provided along with this file, can be used to
58extract info out of /var/log/messages. Call it:
59  show_event_log <first> [<last> [<list of event types>] ]
60<first> is the sequence number of the first event you are interested in.
61<last>  is the number of the last event. You may write 'last' literally. It may
62        also be omitted if you want to see a single event.
63<list>  is a list of event types you like to see. If you omit it, you get most
64        events, not all. Some are exclude by default. Use " " as list if you
65        want to see really all. Or edit the list of skipped events in the first
66        lines of the script
67
68If you don't use /var/log/messages as the logfile you may set the environment
69variable MESSAGES=<logfile>.
70
Note: See TracBrowser for help on using the repository browser.