Performance-Helping FSGSBASE Patches Spun For Linux A 13th Time
Linux kernel developer Sasha Levin of Microsoft has been overseeing these patches recently as even Microsoft has seen performance benefits to these kernel patches presumably for their Azure workloads. The FSGSBASE patches have the possibility of helping out various workloads particularly those like Java and software frequently performing context switching, one of the areas harmed in recent years by all of the CPU security mitigations.
Earlier this month I did run benchmarks of the recent FSGSBASE patches on Intel and AMD CPUs and indeed for some workloads these patches did enhance the performance.
With the v13 patches, some of the patches have been reformatted and some of the changes omitted. Unfortunately due to the timing of these patches and the Linux 5.8 merge window likely opening next week, we likely won't see this work merged until at least Linux 5.9 if later given other upstream developers don't see to be in a rush in supporting this years old instruction.