As another poster reported a few months ago, DRI on amd64 works if one
changes the type of 'off' in uvm_device.c to vsize_t from off_t, as it
needs to hold a 64-bit value.  What would be the proper way of fixing
this?

Also, I got MesaLib 6.5.3 to build with the x86_64 assembly by
building it with -fvisibility=hidden to avoid relocation issues.  It's
actually _MORE_ stable than it was on i386; the PageFlip option
doesn't cause screen corruption, for instance.  Strange (my video
card, an R423, does have 64-bit PCIE BARs).

I'd like to fix this in the kernel, but I do not know what the
underlying problem is (if there is one, but I suspect there is).

Regards,

--Blair