A Fix Is Pending For That Linux 5.15 Performance Regression

First up are some benchmarks of the Intel Core i9 11900K "Rocket Lake" system with Linux 5.14 stable, Linux 5.15-rc1 when first noticing the regression, and then Linux 5.15 with this new patch (the "flush-in-the-ref" run).

Indeed the Linux 5.15 performance is back to where it was with Linux 5.14...

Code compilation was one of the areas where Linux 5.15 was regressing on multiple systems in my tests. Fortunately, that's now cleared up with this patched kernel.