Comment # 24 on bug 99275 from Reimar Imhof

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).