https://bugs.freedesktop.org/show_bug.cgi?id=43655
--- Comment #5 from Michel Dänzer michel@daenzer.net 2011-12-15 10:18:01 UTC --- It sounds like the problem may happen or not with a certain probability with any given kernel. You should probably test each kernel a certain number of times before declaring it as good, or the bisection may not work correctly.