In an xfce4 panel, add an "action buttons" plugin, then configure its appearance as "buttons" in its properties (right click contextual menu on the icon in the panel).
Then if you left click to make the buttons appear, it takes a very long time for the window to appear.
The window manager compositor is disabled.
On radeon southern island, it takes more time than on radeon evergreen with glamor accelmethod enabled.
Running up-to-date fedora rawhide.
update: it's way faster now. But still, there is a lag of a few seconds on a quad-core 2.7 GHz...
*** Bug 82141 has been marked as a duplicate of this bug. ***
(In reply to comment #2)
> But still, there is a lag of a few seconds on a quad-core 2.7 GHz...
With glamor from current xserver Git, it's about 2s with the compositor disabled and about 1s with the compositor enabled. I take it that's still not acceptable for resolving this report?
Solving this for good probably requires identifying the software rendering fallback path(s) hit by the Xfce logout dialog, and implementing hardware accelerated paths for them.
Fix posted for review: http://lists.x.org/archives/xorg-devel/2014-August/043445.html
Author: Michel Dänzer <email@example.com>
Date: Wed Aug 6 10:30:25 2014 +0900
glamor: Add glamor_copy_fbo_cpu() for CopyArea to non-GPU destination
This provides a speedup e.g. when the destination is an SHM pixmap.