https://bugs.freedesktop.org/show_bug.cgi?id=36563
--- Comment #7 from Rune K. Svendsen runesvend@gmail.com 2011-05-26 12:35:15 PDT --- I have found a reliable way of reproducing this bug on this computer at least.
Compiz must be enabled. 1. Go to CompizConfig Settings Manager (ccsm) 2. Under "Window Management"->"Resize Window" in the "General" tab, choose "Normal" as the Default Resize Mode. This will cause windows to resize real-time, as they are dragged by their corners/sides. 3. Open up gnome-terminal and start resizing the window quickly, it will lag a lot and eventually hang compiz.
The output of gdb after attaching is similar to that of the "Second output" (https://bugs.freedesktop.org/attachment.cgi?id=47160) attached to this bug report. Ie. line #3 in Thread 1 is "radeon_bo_destroy" followed by "radeon_bo_reference" "r600_bo_destroy" "r600_bo_reference" etc.