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Chris Pollock
Asked: 2015-05-20 07:26:22 +0800 CST

How to troubleshoot a video freeze

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System information:

  • Ubuntu 14.04.2 LTS
  • Gnome 3.12.2
  • kernel 4.0.0-997-generic #201503310205 SMP Tue Mar 31 02:07:04 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux (this is an updated drm/intel-next kernel from here)
  • Module intel:
    • vendor="X.Org Foundation compiled for 1.15.1
    • version = 2.99.917.

The above kernel and driver were suggested by the intel-gfx mailing list. The box itself is a Dell Optiplex 780.

The problem that I've been experiencing since December of last year is periodically the video will lockup for no known reason.

I had submitted a bug report #1402331 and also contributed information to the one at freedesktop.org #75394

The last time the Hangcheck...error showed up was 19 March of this year however since then there have been numerous occasions where I would notice a black screen with just a movable mouse cursor. Other times the video would freeze when browsing using Firefox. In both instances I'd be able to CTRL>ALT>F1 into a console and reboot. The below was suggested by the intel-gfx list:

That's unfortunate. Not a GPU hang then. The next task is then to
inspect each process and see who is stuck talking to X: either going to
be unity (or compiz, gnome-shell etc) or the xscreensaver. And then try
and figure out the best way to postmortem it given that we are looking
for a missing piece of chatter.

A stacktrace (both user/kernel just in case) for X, unity would probably
be the next step.

I have gone here https://wiki.ubuntu.com/X/Backtracing and attempted to use the first option after a freeze happens.

Here is my kern.log from two freezes that happened on 10 May and 13 May. I don't know if any information there will be helpful or not - http://paste.ubuntu.com/11226544/.

Here is the output of sudo lshw - http://paste.ubuntu.com/11226588/.

My /var/log/Xorg.0.log - http://paste.ubuntu.com/11226839/.

So, my question after all of the above is just how do I further troubleshoot this problem? I can replicate it just by turning on X-Screensaver again.

kernel

1 Answers

  1. I do get this as well from time to time. Using the console not to reboot, but to find out what is happening revealed that it was a problem with compiz for me.

    The solution was to kill compiz and then return to the graphical console. Compiz would be restarted and everything was back to normal.

    To kill compiz via the console, type the following on the commandline:

    killall -KILL compiz

    After that use Ctrl-Alt-F7 to return to your graphical session wich will automatically restart compiz for you and you can continue without reboot.

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