AMD's Marek Olšák Lands Even More OpenGL Threading Improvements Into Mesa 20.1

One month ago to the day I was writing about OpenGL threading improvements for Mesa 20.1 and since then more "GLTHREAD" work has materialized and successfully landed for improving the Mesa OpenGL driver performance.

Longtime AMD open-source developer Marek Olšák has been leading this recent work on GLTHREAD. Over the past month he has landed various GLTHREAD optimizations and whitelisting more games to flip on "mesa_glthread" by default.

Today another patch series as "part one" was merged providing "many optimizations" to GLTHREAD.

In digging through the round of just-merged patches, avoiding the previous null buffer object in code turned out to be a big performance win. The TORCS game is running about 5% faster as a result of those changes.

Another optimization merged this morning is optimizing initialization of new VAOs. This optimized initialization of OpenGL vertex array objects should help out as up to now Marek noticed VAO creation was representing "substantial" CPU overhead. No numbers though on the exact benefits for these other patches.

As part of this broader merge request with more patches yet to land, compared to Mesa Git his GLTHREAD optimizations are yielding a 16% improvement for TORCS or a 40% increase in comparison to Mesa Git without GLTHREAD. TORCS is The Open Racing Car Simulator open-source software.

Hopefully the rest of this GLTHREAD work can land ahead of the Mesa 20.1 feature freeze happening later this month while the first Mesa 20.1 stable release is expected around the end of May.