Comment 82 for bug 1072206

I seem to be reproducing this bug or similar on Ubuntu 14.04, using gnome-panel (gnome classic) + compiz, gtx 600 (driver: nvidia-352.63). The comments in #80 and #79 hit close to home.

I can reproduce it easily by running 'mplayer video' and pressing alt-tab. This renders compiz unusable and cpu usage for compiz goes to 100% usage and stays as such until killed. Occasionally compiz will crash instead of hanging, but I think there may be some specific interactions/key presses, part of my futile attempts at recovering the session while not fully unusable (even if it's already going berzerk by then) that causes it to end up crashing rather than hanging.

FWIW, I've Attached gdb backtrace of all threads. I also recorded the perf events for compiz after reproducing the issue using mplayer.

Alternatively, I have noticed that this started to happen more frequently when I began to use more than one firefox window open (I don't think tab count matters much as I've always been a tab hoarder and I have reduced substantially now). I did experience similar behavior with flash based multimedia content in full screen and alt-tab to switch back to the browser. It does not reproduce easily tough.

This behavior started to be noticed about 3 months ago (could be less, could be more, I can't be any more precise, I'm afraid)

Would be great to root cause it and I am happy to help.