Exposing GPU information for userspace processes

[Dave Airlie]

On Wed, Jul 10, 2013 at 7:45 AM, Rhyland Klein <rklein at nvidia.com> wrote:
> We are currently looking into exporting some information from the linux
> kernel to userspace about the GPU. This information is specific per
> board as the data can vary depending on the fuses burnt on the board.
>
> Right now we are leaning towards adding sysfs properties to our existing
> nodes to share this information.
>
> Before we write up the patches and update our userspace apps to check
> the new locations, we wanted to make sure there wasn't a more
> accepted/proper way to export information already.
>
> Right now for instance we want to export a property to say how many
> pixel pipes there are. This could then be exported in something like:
>
> /sys/bus/platform/drivers/gr3d/54180000.gr3d/num_pixel_pipes
>
> Is this the best approach to take right now or is there another way we
> should export this and similar HW specific information?

All the x86 GPU drivers use gpu specific get param ioctls for this so far.

e.g. drivers/gpu/drm/radeon/radeon_kms.c:radeon_info_ioctl

Dave.

Dave.