https://bugs.freedesktop.org/show_bug.cgi?id=99275
--- Comment #24 from Reimar Imhof tuxuser@quantentunnel.de --- I forgot to mention: When running the 4.8 kernel with high cpu load (about 100%) (for example building a kernel) the 4.8 kernel also produces flickering and shows artifacts from the background when re-sizing a window. But the 4.9 kernel shows this bug even with very low cpu load when the machine is idle (see comment#5).