When using PBOs to upload texture data, which call triggers the actual DMA operation?

[Clemens Eisserer]

Hi Marek,

Thanks a lot for the detailed explanation. I asked it here, because I
was not sure whether the details I asked are driver specific.

> All GPU operations are asynchronous and don't
> cause any stalls on the CPU side.

And what about GPU stalls? From what I read it seems currently DMA can
not operate concurrently with the 3D engine, so would it be benefitial
for upload performance to instead use SSBOs located in GTT accessed by
a shader, so the 3D engine does perform the copy itself?

Thanks, Clemens