I'm supporting a friend running Ubuntu 14.04 LTS. After initial installation, we used tasksel
to convert to Ubuntu GNOME.
He has since encountered a perplexing issue where after opening a particular application, the X session absorbs two CPUs and cannot be killed.
This particular application utilizes OpenGL rendering. This unit has an NVIDIA graphics card, and the proprietary driver is installed.
From his account, it appears that the lockup happens after an arbitrary amount of time after opening the application (not dependent upon closing that application).
I had him run through his steps in front of me so I could see it myself. The following occurred:
- Boot system
- Log in via GDM
- Start 3 instances of Thunar
- Launch application
- Advance through menu and initialize OpenGL rendering
- Screen flickers to black a few times, and rendering starts
- Application suffers internal error (unrelated to the issue)
- Close application after receiving error message
- Wait less than 15 seconds
- X session becomes unresponsive except to mouse movement input
- SSH remote login from my machine
- Attempt to kill X; no result
- Attempt to restart GDM:
sudo service gdm restart
; successful, but X session still not dead - Attempt to kill system:
sudo shutdown -r now
- Connection closes in preparation to shutdown
- Machine does not power off
- Attempt to reconnect; connection refused (OpenSSH no longer running)
- Force kill machine (hardware power button)
What information is needed in order to diagnose this issue? I've never run into anything like it. This unit previously ran Arch with the same version of GNOME 3 with no issues, using the same driver (though probably different versions).
EDIT: We attempted reinstalling with Unity, and after installing the proprietary driver (nvidia-current
), the issue appears to be persistent. An interesting occurrence was when a similar freeze occurred on the login prompt, before even launching any applications.