[cairo] Xlib : SHMPixmaps not allowed by default in NVIdia drivers.

[ed44]

NVidia users have to add an option in xorg.conf like :
Option "AllowSHMPixmaps" "1"

...to be able to use fast xlib surfaces.

Is there a reason why shm-images are not used in cairo ?
If not, is it planned ?

Thanks