ubuntu-multiseat team mailing list archive

[Greg Hood <ghood@xxxxxxx>]

We've been having trouble getting a greeter screen to reliably appear on
all seats of our 6-seat configuration.   After a reboot usually only 3 to 5
seats will have a greeter running.  Seat 0 always does, but which of the
other 5 seats have greeters varies from one boot to the next.  After
enabling lightdm debugging output with -d in /etc/init/lightdm.conf, it
seems that the problem is that lightdm does not receive a signal back from
all of the X servers.  In /var/log/lightdm/lightdm.log we always have six
"Waiting for ready signal" lines, but a smaller number of "Got signal from
X server" lines.  The complete lightdm.log file is attached.  All six X
server processes are running, and their /var/log/Xorg.*.log files are
identical except for very slight timing differences and, of course, video
card IDs and PCI addresses.

Someone else mentioned on their blog at
https://cedarandthistle.wordpress.com/2015/01/31/multiseat-and-anaconda-bugs/
that "Occasionally lightdm starts the X server, but never gets a signal
back saying that it’s ready, so they both sit there waiting for the other
process."  Although that was for a 4-seat Fedora installation, that seems
to be the same problem that we're seeing on Ubuntu.

Does anyone have any idea why these signals are getting lost, or how to go
about fixing things?
Thanks.
--Greg

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.10.3, UID=0 PID=3309
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-greeter-wrapper.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/50-xserver-command.conf
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/90-nvidia.conf
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf.d/99-multiseat.conf
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: Registered seat module xlocal
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Registered seat module unity
[+0.00s] DEBUG: Registered seat module surfaceflinger
[+0.01s] DEBUG: Monitoring logind for seats
[+0.01s] DEBUG: New seat added from logind: seat0
[+0.01s] DEBUG: Seat: Starting
[+0.01s] DEBUG: Seat: Creating greeter session
[+0.01s] DEBUG: Seat: Creating display server of type x
[+0.01s] DEBUG: Quitting Plymouth
[+0.03s] DEBUG: Using VT 7
[+0.03s] DEBUG: Seat: Starting local X display on VT 7
[+0.03s] DEBUG: DisplayServer x-0: Logging to /var/log/lightdm/x-0.log
[+0.03s] DEBUG: DisplayServer x-0: Writing X server authority to /var/run/lightdm/root/:0
[+0.03s] DEBUG: DisplayServer x-0: Launching X Server
[+0.03s] DEBUG: Launching process 3320: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.03s] DEBUG: DisplayServer x-0: Waiting for ready signal from X server :0
[+0.03s] DEBUG: New seat added from logind: seat-2
[+0.03s] DEBUG: Seat seat-2 has property CanMultiSession=no
[+0.03s] DEBUG: Seat: Starting
[+0.03s] DEBUG: Seat: Creating greeter session
[+0.03s] DEBUG: Seat: Creating display server of type x
[+0.03s] DEBUG: Seat: Starting local X display
[+0.03s] DEBUG: DisplayServer x-1: Logging to /var/log/lightdm/x-1.log
[+0.03s] DEBUG: DisplayServer x-1: Writing X server authority to /var/run/lightdm/root/:1
[+0.03s] DEBUG: DisplayServer x-1: Launching X Server
[+0.03s] DEBUG: Launching process 3322: /usr/bin/X -core :1 -seat seat-2 -sharevts -auth /var/run/lightdm/root/:1 -nolisten tcp
[+0.03s] DEBUG: DisplayServer x-1: Waiting for ready signal from X server :1
[+0.03s] DEBUG: New seat added from logind: seat-5
[+0.03s] DEBUG: Seat seat-5 has property CanMultiSession=no
[+0.03s] DEBUG: Seat: Starting
[+0.03s] DEBUG: Seat: Creating greeter session
[+0.03s] DEBUG: Seat: Creating display server of type x
[+0.03s] DEBUG: Seat: Starting local X display
[+0.03s] DEBUG: DisplayServer x-2: Logging to /var/log/lightdm/x-2.log
[+0.03s] DEBUG: DisplayServer x-2: Writing X server authority to /var/run/lightdm/root/:2
[+0.03s] DEBUG: DisplayServer x-2: Launching X Server
[+0.03s] DEBUG: Launching process 3323: /usr/bin/X -core :2 -seat seat-5 -sharevts -auth /var/run/lightdm/root/:2 -nolisten tcp
[+0.03s] DEBUG: DisplayServer x-2: Waiting for ready signal from X server :2
[+0.03s] DEBUG: New seat added from logind: seat-3
[+0.03s] DEBUG: Seat seat-3 has property CanMultiSession=no
[+0.03s] DEBUG: Seat: Starting
[+0.03s] DEBUG: Seat: Creating greeter session
[+0.03s] DEBUG: Seat: Creating display server of type x
[+0.03s] DEBUG: Seat: Starting local X display
[+0.03s] DEBUG: DisplayServer x-3: Logging to /var/log/lightdm/x-3.log
[+0.03s] DEBUG: DisplayServer x-3: Writing X server authority to /var/run/lightdm/root/:3
[+0.03s] DEBUG: DisplayServer x-3: Launching X Server
[+0.03s] DEBUG: Launching process 3325: /usr/bin/X -core :3 -seat seat-3 -sharevts -auth /var/run/lightdm/root/:3 -nolisten tcp
[+0.03s] DEBUG: DisplayServer x-3: Waiting for ready signal from X server :3
[+0.03s] DEBUG: New seat added from logind: seat-1
[+0.03s] DEBUG: Seat seat-1 has property CanMultiSession=no
[+0.03s] DEBUG: Seat: Starting
[+0.03s] DEBUG: Seat: Creating greeter session
[+0.03s] DEBUG: Seat: Creating display server of type x
[+0.03s] DEBUG: Seat: Starting local X display
[+0.03s] DEBUG: DisplayServer x-4: Logging to /var/log/lightdm/x-4.log
[+0.03s] DEBUG: DisplayServer x-4: Writing X server authority to /var/run/lightdm/root/:4
[+0.03s] DEBUG: DisplayServer x-4: Launching X Server
[+0.03s] DEBUG: Launching process 3326: /usr/bin/X -core :4 -seat seat-1 -sharevts -auth /var/run/lightdm/root/:4 -nolisten tcp
[+0.03s] DEBUG: DisplayServer x-4: Waiting for ready signal from X server :4
[+0.03s] DEBUG: New seat added from logind: seat-4
[+0.03s] DEBUG: Seat seat-4 has property CanMultiSession=no
[+0.03s] DEBUG: Seat: Starting
[+0.03s] DEBUG: Seat: Creating greeter session
[+0.03s] DEBUG: Seat: Creating display server of type x
[+0.03s] DEBUG: Seat: Starting local X display
[+0.03s] DEBUG: DisplayServer x-5: Logging to /var/log/lightdm/x-5.log
[+0.03s] DEBUG: DisplayServer x-5: Writing X server authority to /var/run/lightdm/root/:5
[+0.03s] DEBUG: DisplayServer x-5: Launching X Server
[+0.03s] DEBUG: Launching process 3328: /usr/bin/X -core :5 -seat seat-4 -sharevts -auth /var/run/lightdm/root/:5 -nolisten tcp
[+0.03s] DEBUG: DisplayServer x-5: Waiting for ready signal from X server :5
[+0.03s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.03s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.03s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat1
[+0.03s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat2
[+0.03s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat3
[+0.03s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat4
[+0.03s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat5
[+0.05s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.05s] DEBUG: User /org/freedesktop/Accounts/User22643 added
[+0.07s] DEBUG: User /org/freedesktop/Accounts/User6341 added
[+0.07s] DEBUG: User /org/freedesktop/Accounts/User12670 added
[+0.08s] DEBUG: User /org/freedesktop/Accounts/User19087 added
[+0.09s] DEBUG: User /org/freedesktop/Accounts/User12906 added
[+0.10s] DEBUG: User /org/freedesktop/Accounts/User20033 added
[+0.10s] DEBUG: User /org/freedesktop/Accounts/User18475 added
[+4.62s] DEBUG: Got signal 10 from process 3328
[+4.62s] DEBUG: DisplayServer x-5: Got signal from X server :5
[+4.62s] DEBUG: DisplayServer x-5: Connecting to XServer :5
[+4.62s] DEBUG: Launching process 3878: /sbin/prime-offload
[+4.62s] DEBUG: Process 3878 exited with return value 0
[+4.62s] DEBUG: Seat: Exit status of /sbin/prime-offload: 0
[+4.62s] DEBUG: Seat: Display server ready, starting session authentication
[+4.62s] DEBUG: Session: Not setting XDG_VTNR
[+4.62s] DEBUG: Session pid=3884: Started with service 'lightdm-greeter', username 'lightdm'
[+4.67s] DEBUG: Got signal 10 from process 3323
[+4.67s] DEBUG: DisplayServer x-2: Got signal from X server :2
[+4.67s] DEBUG: DisplayServer x-2: Connecting to XServer :2
[+4.67s] DEBUG: Launching process 3907: /sbin/prime-offload
[+4.68s] DEBUG: Process 3907 exited with return value 0
[+4.68s] DEBUG: Seat: Exit status of /sbin/prime-offload: 0
[+4.68s] DEBUG: Seat: Display server ready, starting session authentication
[+4.68s] DEBUG: Session: Not setting XDG_VTNR
[+4.68s] DEBUG: Session pid=3915: Started with service 'lightdm-greeter', username 'lightdm'
[+4.68s] DEBUG: Got signal 10 from process 3326
[+4.68s] DEBUG: DisplayServer x-4: Got signal from X server :4
[+4.68s] DEBUG: DisplayServer x-4: Connecting to XServer :4
[+4.68s] DEBUG: Launching process 3916: /sbin/prime-offload
[+4.68s] DEBUG: Process 3916 exited with return value 0
[+4.68s] DEBUG: Seat: Exit status of /sbin/prime-offload: 0
[+4.68s] DEBUG: Seat: Display server ready, starting session authentication
[+4.68s] DEBUG: Session: Not setting XDG_VTNR
[+4.68s] DEBUG: Session pid=3925: Started with service 'lightdm-greeter', username 'lightdm'
[+4.69s] DEBUG: Got signal 10 from process 3320
[+4.69s] DEBUG: DisplayServer x-0: Got signal from X server :0
[+4.69s] DEBUG: DisplayServer x-0: Connecting to XServer :0
[+4.69s] DEBUG: Launching process 3931: /sbin/prime-offload
[+4.69s] DEBUG: Process 3931 exited with return value 0
[+4.69s] DEBUG: Seat: Exit status of /sbin/prime-offload: 0
[+4.69s] DEBUG: Seat: Display server ready, starting session authentication
[+4.69s] DEBUG: Session pid=3940: Started with service 'lightdm-greeter', username 'lightdm'
[+4.71s] DEBUG: Session pid=3884: Authentication complete with return value 0: Success
[+4.71s] DEBUG: Seat: Session authenticated, running command
[+4.71s] DEBUG: Session pid=3884: Not setting XDG_VTNR
[+4.71s] DEBUG: Session pid=3884: Running command /usr/lib/lightdm/lightdm-greeter-session /usr/sbin/unity-greeter
[+4.71s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+4.71s] DEBUG: Session pid=3884: Logging to /var/log/lightdm/x-5-greeter.log
[+4.72s] DEBUG: Activating login1 session c1
[+4.83s] DEBUG: Session pid=3915: Authentication complete with return value 0: Success
[+4.83s] DEBUG: Seat: Session authenticated, running command
[+4.83s] DEBUG: Session pid=3915: Not setting XDG_VTNR
[+4.83s] DEBUG: Session pid=3915: Running command /usr/lib/lightdm/lightdm-greeter-session /usr/sbin/unity-greeter
[+4.83s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+4.83s] DEBUG: Session pid=3915: Logging to /var/log/lightdm/x-2-greeter.log
[+4.84s] DEBUG: Activating login1 session c2
[+4.84s] DEBUG: Session pid=3925: Authentication complete with return value 0: Success
[+4.84s] DEBUG: Seat: Session authenticated, running command
[+4.84s] DEBUG: Session pid=3925: Not setting XDG_VTNR
[+4.84s] DEBUG: Session pid=3925: Running command /usr/lib/lightdm/lightdm-greeter-session /usr/sbin/unity-greeter
[+4.84s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+4.84s] DEBUG: Session pid=3925: Logging to /var/log/lightdm/x-4-greeter.log
[+4.86s] DEBUG: Activating login1 session c3
[+4.86s] DEBUG: Session pid=3940: Authentication complete with return value 0: Success
[+4.86s] DEBUG: Seat: Session authenticated, running command
[+4.86s] DEBUG: Session pid=3940: Running command /usr/lib/lightdm/lightdm-greeter-session /usr/sbin/unity-greeter
[+4.86s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+4.86s] DEBUG: Session pid=3940: Logging to /var/log/lightdm/x-0-greeter.log
[+4.87s] DEBUG: Activating VT 7
[+4.87s] WARNING: Error using VT_ACTIVATE 7 on /dev/console: Inappropriate ioctl for device
[+4.87s] WARNING: Error using VT_WAITACTIVE 7 on /dev/console: Inappropriate ioctl for device
[+4.87s] DEBUG: Activating login1 session c4
[+4.88s] DEBUG: Session pid=3884: Greeter connected version=1.10.3
[+4.94s] DEBUG: Session pid=3915: Greeter connected version=1.10.3
[+4.94s] DEBUG: Session pid=3925: Greeter connected version=1.10.3
[+4.97s] DEBUG: Session pid=3940: Greeter connected version=1.10.3
[+5.29s] DEBUG: Session pid=3940: Greeter start authentication for ghood
[+5.29s] DEBUG: Session pid=4369: Started with service 'lightdm', username 'ghood'
[+5.29s] DEBUG: Session pid=3884: Greeter start authentication for ghood
[+5.29s] DEBUG: Session: Not setting XDG_VTNR
[+5.29s] DEBUG: Session pid=4370: Started with service 'lightdm', username 'ghood'
[+5.29s] DEBUG: Session pid=3915: Greeter start authentication for awetzel
[+5.29s] DEBUG: Session: Not setting XDG_VTNR
[+5.29s] DEBUG: Session pid=4371: Started with service 'lightdm', username 'awetzel'
[+5.29s] DEBUG: Session pid=3925: Greeter start authentication for dittrich
[+5.29s] DEBUG: Session: Not setting XDG_VTNR
[+5.29s] DEBUG: Session pid=4372: Started with service 'lightdm', username 'dittrich'
[+5.30s] DEBUG: Session pid=4369: Got 1 message(s) from PAM
[+5.30s] DEBUG: Session pid=3940: Prompt greeter with 1 message(s)
[+5.30s] DEBUG: Session pid=4370: Got 1 message(s) from PAM
[+5.30s] DEBUG: Session pid=3884: Prompt greeter with 1 message(s)
[+5.30s] DEBUG: Session pid=4371: Got 1 message(s) from PAM
[+5.30s] DEBUG: Session pid=3915: Prompt greeter with 1 message(s)
[+5.30s] DEBUG: Session pid=4372: Got 1 message(s) from PAM
[+5.30s] DEBUG: Session pid=3925: Prompt greeter with 1 message(s)
[+14.27s] DEBUG: User /org/freedesktop/Accounts/User6341 changed
[+14.44s] DEBUG: User /org/freedesktop/Accounts/User22643 changed
[+14.60s] DEBUG: User /org/freedesktop/Accounts/User12670 changed
[+14.65s] DEBUG: User /org/freedesktop/Accounts/User19087 changed
[+14.73s] DEBUG: User /org/freedesktop/Accounts/User12906 changed
[+72.89s] DEBUG: User /org/freedesktop/Accounts/User6341 changed
[+73.18s] DEBUG: User /org/freedesktop/Accounts/User22643 changed
[+73.49s] DEBUG: User /org/freedesktop/Accounts/User12670 changed
[+73.60s] DEBUG: User /org/freedesktop/Accounts/User19087 changed
[+73.76s] DEBUG: User /org/freedesktop/Accounts/User12906 changed
...