Comment # 47 on bug 1028575 from Mircea Kitsune

After months of careful testing and experimentation, I have discovered what
seems to be the primary trigger of this freeze at last. It's not what triggers
it per say, but what "rigs" the system and causes it to crash within the course
of the next hours... the actual trigger is alt-tab switching between windows,
or certain desktop effects playing.

The freeze is mined into the system when you disable and re-enable KDE desktop
compositing. If I hit Alt + Shift + F12 to turn off desktop effects, then hit
the key combo to turn them back on... there is a great chance that within a few
hours the crash occurs. If I don't toggle compositing on the run and just leave
it enabled after the system has started, I seem to be fine... this only happens
if I turn it off and back on during runtime. It's uncertain whether anything
else mines the system, but this is almost always what seems to do it for me.

Notice: I use OpenGL 3.1 for desktop compositing. I remember selecting OpenGL
2.0 long ago, but that still caused the freeze at that time. I can't use
Xrender on a daily basis as many effects don't work with it. No other
compositor options seem to affect the problem either.

It would be highly appreciated if at least after this information, the
developers and maintainers could finally look at this issue! It has taken me
months to confirm this as a cause, and I really hope this information
(alongside dozens of comments and logs I have posted) can finally be put to
use.