[RFC] drm/ttm: add minimum residency constraint for bo eviction

[Thomas Hellstrom]

On 11/28/2012 10:51 PM, Marek Olšák wrote:
> I think the problem with Radeon/TTM is much deeper. Let me demonstrate
> it on the following example.
>
> Unigine Heaven needs about 385MB of space for static resources, that's
> only 75% of my 512MB card. Yet, TTM is not capable of getting all of
> that into VRAM. If I allow GTT placements, I get 20 fps, which is the
> old Mesa behavior. If I force VRAM placements, I get 3 fps, because we
> validate buffers 10 times per frame and there's probably a lot of
> buffer evictions during each validation.
>

Marek,
Did you look at the total amount of referenced buffers in the ring 
including vertex buffers?

Depending on how hard you throttle, I guess vertex / index buffer data 
referenced by the
ring commands may well exceed the VRAM limitation.

/Thomas