> However, the AGP code will call bus_dmamem_alloc
> when triggered by a request via an ioctl call (it's hard to
> change this, unless you want to allocate the entire AGP aperture
> upfront, which can be 256M in size..). 

I never see the AGP code yet, but is it also hard for the AGP code to
pool a small number of pages?

If the AGP code can split ioctl request into a repetation of pieces
which only requires given few pages, allocation of the pages in attach
would be reasonable.
If the AGP code requires 256MB memory at once, it's hopeless, anyway.

Atsushi Onoe