On Tue, Apr 20, 2021, 09:25 Marek Olšák <maraeo@gmail.com> wrote:

> Daniel, imagine hardware that can only do what Windows does: future fences
> signalled by userspace whenever userspace wants, and no kernel queues like
> we have today.
>

Hmm, that sounds kinda like what we're trying to do for Libre-SOC's gpu
which is basically where the cpu (exactly the same cores as the gpu) runs a
user-space software renderer with extra instructions to make it go fast, so
the kernel only gets involved for futex-wait or for video scan-out. This
causes problems when figuring out how to interact with dma-fences for
interoperability...

Jacob Lifshay