AMD INVLPGB Linux Patches Updated For Broadcast TLB Invalidation

Right before Christmas Meta engineer Rik van Riel posted Linux kernel patches to make use of the AMD INVLPGB instruction for broadcast TLB invalidation. INVLPGB is present in AMD Ryzen and EPYC processors since Zen 3 and early data showed by Rik indicated nice improvement. A third iteration of those patches have already been posted as this AMD INLVPGB usage works its way to the mainline kernel.

The Linux patches for using the INVLPGB instruction for AMD broadcast TLB invalidation have been further cleaned up with the patches posted on Monday. Code cleanups and change-log fixes suggested during the prior round of review are now in place for the v3 patches. Last week also saw the v2 patches that weren't specifically called out on Phoronix but brought some minor bug fixes and other updates.

The metrics shown with the prior patch versions still apply:

Those wanting to try out these patches for some New Year fun can find them on the Linux kernel mailing list where they continue undergoing review.

In case you missed it over the weekend I also posted some AMD INVLPGB benchmarks showing up to a few percent gain in various real-world workloads, besides the crazier numbers in the more synthetic benchmarks. More AMD INVLPGB benchmarks to come on Phoronix with more hardware and more workloads as my time allows. Hopefully these AMD INVLPGB benchmarks manage to make it to the mainline Linux kernel in the near future.