Benchmarking The Performance Impact To AMD Inception Mitigations
For some of the web browser benchmarks there were some small performance penalties incurred with this new mitigation.
Overall it comes down to what workloads you are engaged in whether you may notice any performance difference when upgrading your Linux kernel (or otherwise being patched for Inception on your given OS) on an AMD Zen desktop or server. For the most part users are unlikely to notice anything drastic, aside from some sizable database performance hits in a few cases. It's unfortunate seeing some of these regressions due to the Inception mitigation but ultimately is unlikely to really change the competitive standing of AMD's latest wares on Linux. Most of the prior AMD CPU security mitigations have also not resulted in any performance degradation, so this Inception mitigation difference is a bit rare. It also was announced on the same day as Intel Downfall where there was again a sizable hit to Intel CPU performance. For those wanting to avoid the new mitigation, there is always the "mitigations=off" route or the "spec_rstack_overflow=off" as used in this round of testing (the "off" metrics) for only disabling the Inception/SRSO and leaving all other CPU security mitigations at their respective defaults. I continue to run more AMD Inception and Intel Downfall benchmarks in looking to uncover any other performance differences worth mentioning.
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