AMD's OpenGL Linux Driver Already Scored A Nice Performance Win For 2024

While much of the focus by graphics vendors these days is on their Vulkan driver support/performance and less so about OpenGL in 2024, AMD's open-source RadeonSI Gallium3D driver for Linux systems is still showing no signs of slowing down and still scoring more performance victories.

Prolific Radeon Mesa developer Marek Olšák has landed his first significant performance optimization patch series of 2024. The 32 patches refactor various RadeonSI Gallium3D and AMDGPU winsys code for Mesa 24.0. They "radically" optimize the AMDGPU winsys that is between the AMD Mesa drivers and the AMDGPU kernel driver.

A complete rewrite of the buffer object (BO) fence tracking code decreases the command submission (CS) thread overhead by 46% and "massively decreases" the CPU cache footprint for buffer object fences. In one CPU-bound benchmark the performance goes up by 12%.

With a 1-level slab allocator that is also added, another CPU bound benchmark sees 10~18% higher performance. The code was merged for Mesa 24.0.

For those wondering, while this benefits CPU-bound OpenGL workloads, it seems one of AMD's main incentives and interests for continuing to optimize their open-source OpenGL driver in 2024 is around the continued OpenGL workstation use by apps. In paricular, the 12% win is racked up for SPECViewPerf:

"This decreases the time spent in amdgpu_cs_submit_ib from 15.4% to 8.3% in VP2020/Catia1, which is a decrease of CPU load for that thread by 46%. Overall, it increases performance by a small number in CPU-bound benchmarks. The biggest improvement I have seen is VP2020/Catia2, where it increases FPS by 12%."

Nice job to Marek and a great way to kick off 2024.