OpenCL/OpenGL contention on a device (was Re: x11/nvidia-driver-340 and OpenCL)

[Scott Bennett]

Arto Pekkanen <isoa at kapsi.fi> wrote:

> If the GPU driver is implemented properly there will be no stutter or
> other problems even when running OpenCL jobs.

     Really!  So an OpenCL work item that needs, say, nearly all the available
memory on a graphics device and a 3D shader that has similar memory
requirements will not interfere with each other?  That seems rather magical
somehow, even if the OpenGL stuff always has a higher priority inside the GPU
than the OpenCL stuff.
>
> In Windows there is no problem running OpenCL jobs on the same device
> that operates your display. Like running a crypto currency miner while
> browsing the web. Playing games won't work well, but basic stuff you can do.
>
     Is that partly because the memory requirements of the "basic stuff" are
typically tiny when compared to the capacity of today's graphics devices?

> TL;DR when the FreeBSD GPU driver and all the userland bits are up to
> date, I'd expect there to be no issues with stuttering.
>
     Do you know the driver well enough to explain to me how the scheduling
inside a graphics device works?  I've never seen a description of the
algorithm(s) anywhere.


                                  Scott Bennett, Comm. ASMELG, CFIAG
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