Comment 371 for bug 1140716

I have, I think, a reliable way to trigger this behavior, if that helps. It requires a non-trivial setup, though.

I have gnome-shell running on dual monitors. The first is 1920x1200, the second is 1920x1080 (not sure if the resolution difference matters). If I run a full-screen game on The 1920x1200 monitor, I get freezes, and notes in the dmesg about hangcheck timers and kickrings ("stuck wait on blitter ring").

I believe OpenGL acceleration of the desktop is important, because the freezes are not triggered in fluxbox, for instance. I'm not sure if the game itself needs to be using OpenGL, or if the full-screen window is the triggering factor, or something else entirely. It is important that the game keep the monitors distinct, and only go full screen on one. I just tried it on Battle for Wesnoth, and full screen there sets the monitors to mirror, which doesn't trigger the problem.

This is on an i7 4770, if that matters.

I realize this is may be difficult to put together for a test setup, but I thought I'd mention it.