https://bugs.freedesktop.org/show_bug.cgi?id=106175
--- Comment #43 from bmilreu@gmail.com --- (In reply to Brandon Wright from comment #42)
This is pretty serious. Just moving the mouse cursor around while something slightly GPU-heavy is running at 60hz can produce frame-skipping.
I switched the display core off with amdgpu.dc=0 and everything got significantly smoother and chromium doesn't chug on heavy pages any more.
I'm using 4.19.x. I haven't tried the drm-next-4.21-wip tree yet.
Dont need to try drm-next-4.21-wip, just did and it still has the issue
If devs want an easy test case, use these links for reproducing it in chromium:
https://www.vsynctester.com/ https://www.testufo.com/photo https://www.slither.io
move the cursor around, move/resize some windows. you will notice it
the vsync/cursor stutters and frame-skips are pretty noticeable with dc=1 on all three links
KWin, compton, TearFree, mutter, xfwm4 all have the same problems.