Linux 5.11 Is Regressing Hard For AMD Performance With Schedutil

Separately I fired off more Linux 5.10 vs. 5.11 tests on the AMD Ryzen 9 5900X with more desktop focused workloads while testing not only the schedutil and performance governors but also "ondemand" as what at least on older kernels is still the common default.

For the open-source first person shooter game Xonotic, Schedutil on Linux 5.11 led to an immediate drop in performance... Meanwhile even Ondemand was in better shape on Linux 5.11 than Schedutil and close to the performance offered by the performance governor.

Basemark's OpenGL benchmark was another case seeing a smaller but still measurable and reproducible hit to the performance on Linux 5.11 only under Schedutil.

With other Linux games and graphics tests on the AMD Ryzen 9 5900X, in all of the cases Schedutil was seeing sizable hits to the performance under Linux 5.11 while the performance and ondemand governor performance was stable.