Created attachment 122428 [details]
DDX: xf86-video-ati, 7.6.1
Since updating from xorg-server 1.18.1 to 1.18.2, Xorg will use 100% of one CPU constantly.
bisecting the issue led to the commit
Author: Michel Dänzer
Date: Wed Feb 24 16:52:58 2016 +0900
present: Requeue if flip driver hook fails and target MSC not reached
For flipping, we wait for the MSC before the target MSC and then call
the driver flip hook. If the latter fails, we have to wait for the
target MSC before falling back to a copy, or else it's executed too
Fixes glxgears running at unbounded framerate (not synchronized to the
refresh rate) in fullscreen if the driver flip hook fails.
Reviewed-by: Chris Wilson
Signed-off-by: Michel Dänzer
(cherry picked from commit e7a35b9e16aa12970908f5d55371bb1b862f8f24)
The Xorg.0.log looks clean, but I'll attach it anyway for further info.
I tried with PageFlip (and TearFree) disabled, but that didn't change the outcome.
Reverting the commit on top of 1.18.2 leads to normal behaviour.
Dupe of bug 94596 ?
Yes, certainly looks like it, thanks for the pointer.
I did perform a search, but didn't find that one.
*** This bug has been marked as a duplicate of bug 94596 ***