Fade plugin together with trailfocus causes high CPU usage

[Petteri Aimonen]

To reproduce:

1. Enable the Fade and Trailfocus plugins. Set Trailfocus "Saturation Level of Unfocused Windows" to 80.

2. Open a few windows and close one of them.

3. Observe that compiz uses a lot more CPU (30% for me) than usual.

Steps I have used to debug:

1. In gdb, set breakpoint to CompositeScreen::handlePaintTimeout and check 'scheduled' at the end of the function. Observe that it repaints constantly.

2. Set breakpoint to PrivateCompositeScreen::scheduleRepaint. Observe that calls come from FadeWindow::glPaint.

3. In FadeWindow::glPaint, the new saturation value seems to always be different than the value in fAttrib. Both values remain constant from call to call.

My hunch is that the two plugins are competing to set the saturation value. However I haven't studied the source code in depth so I can't be sure if that is a correct guess.

[Petteri Aimonen (jpa-lp)]

Oh well, was going to add information with apport bug apparently it crashes due to some unicode bug. Well, here is the stuff manually:

Release: 12.10
package 'compiz' version: 1:0.9.8.4+bzr3412-0ubuntu0.1

[Sami Jaktholm (sjakthol)]

I'm marking this bug as a duplicate of bug 1159054 that covers this problem. Thanks for reporting and debugging this one!