Pushing image transport logic down the stack

[Alan Cox]

Ar Sul, 2006-09-03 am 17:16 -0400, ysgrifennodd Owen Taylor:
>  - A copy from and format conversion from your own data to the 
>    shm buffer
>  - A copy from the shm buffer onto the destination drawable

That's an X implementation limitation. Given kernel support it is
perfectly possible to pin those pages and a kernel drive let a video
card DMA those shm buffer pages.