Lavapipe performance question during interactive drawing

[Dave Airlie]

On Fri, 5 May 2023 at 21:30, George Karpathios <gkarpa1 at gmail.com> wrote:
>
> Hi list,
>
> I'm using Lavapipe for Vulkan software rendering support in a modeling application. I notice a large performance hit (with any Mesa version) in the following scenario: The user clicks & drags the mouse in order to create a simple shape (e.g. plane, cube, sphere) dynamically and the result is being rendered (basic gray shading) in real-time alongside the movement of the mouse. Lavapipe seems to be struggling a bit to keep up with this action as the frame time goes up to over 1 second. On the other hand, on a more "static" scene I can get great fps (30-60) while panning/rotating a scene, after Mike Blumenkrantz's recent improvements (many thanks for those again!).
>
> I've uploaded a screenshot of the VS profiler showing the hot path at https://imgur.com/a/qZBkB51  and I'd appreciate hearing your thoughts on this. Thanks once more for your time.

That's a lot of fragment shader recompiles in llvmpipe_update_fs,
LP_DEBUG=fs might give some more info if you have a debug build of
mes.

Dave.