[Mesa-dev] [PATCH v2 13/14] radeonsi: Process multiple patches per threadgroup.

[Marek Olšák]

On Fri, May 13, 2016 at 3:37 AM, Bas Nieuwenhuizen
<bas at basnieuwenhuizen.nl> wrote:
> Using more than 1 wave per threadgroup does increase performance
> generally.  Not using too many patches per threadgroup also
> increases performance. Both catalyst and amdgpu-pro seem to
> use 40 patches as their maximum, but I haven't really seen
> any performance increase from limiting the number of patches
> to 40 instead of 64.

40 may be optimal for existing OpenGL apps on some chips.

Vulkan doesn't set more than 16.

Let's set either 40 or 16 with a comment where the value comes from.

>
> Note that the trick where we overlap the input and output LDS
> does not work anymore as the insertion of the tess factors
> changes the patch stride.

I don't understand this. Can you explain it more?

Marek