Comme=
nt # 81
on bug 10617=
5
from Nicholas Kazlauskas<=
/a>
(In reply to tempel.julian from comment #80)
> It seems like the issue is actually not 100% res=
olved (linux 5.0-rc1).
> The moving of windows is free of stutter now, but moving of windows can
> still negatively affect performance of other windows as long as fullsc=
reen
> vsync is enabled (not necessarily via compositor, can also be done via
> TearFree without a compositor).
> Again, this is best seen on h=
ttps://www.vsynctester.com/ . This seems to
> happen mostly when mouse clicks occur, but sometimes also apart from t=
his.
> It can also happen when just moving the mouse cursor repeatedly on top=
of
> shell elements which trigger pop ups, like the system tray of KDE Plas=
ma.
> As expected, setting amdgpu.dc=3D0 completely "fixes" the is=
sue.
I'm not sure how much of this is actually amdgpu or Plasma.
I can reproduce what you're reporting - red lines and spikes in the graph on
vsynctester.com. This happens whenever I do something like open the dock or
volume widgets in the tray on Plasma with the compositor tearing prevention=
set
to automatic.
However, moving the cursor or moving windows doesn't really seem to affect =
this
and you can verify that in Plasma and other compositors.
As for the difference between dc=3D1 and dc=3D0, that might just be a diffe=
rence in
behavior on the DRM level for atomic vs non-atomic drivers. Or a difference=
in
userspace if they make a distinction there. It affects more than just amdgp=
u at
least.