Benchmarking Clear Linux With KPTI + Retpoline Support

Yesterday Intel landed KPTI page table isolation and Retpoline support in their Clear Linux distribution. Given that one of the pillars of this Intel Open-Source Technology Center platform is on delivering optimal Linux performance, I was curious to see how its performance was impacted. Here are before/after benchmarks on seven different systems ranging from low-end Pentium hardware to Xeon servers.