Re: Tearing and Composite
OK. Those log files (unfortunately I suppose) contain exactly what I'd expect.
Note that GL_SYNC_DISPLAY_DEVICE won't affect VDPAU. I just wanted to confirm that you tried looking at both screens when trying the VDPAU_NVIDIA_SYNC_DISPLAY_DEVICE=DFP-0/1 settings.
Finally, you mentioned that the tear lines moves down the screen. Does it always move smoothly (at a constant rate) down the screen, then flip back to the top, and keep looping, or is it randomly jumping all over the place. Are you running any other graphics-intensive applications alongside the VDPAU app?
Thanks. Sorry this isn't a quick and simple fix!