Linux 4.0 To Linux 4.15 Kernel Benchmarks

When looking at the FS-Mark and CompileBench performance that were impaired by the KPTI/Retpoline overhead, its impact in the grand scheme of things compared to the past few years of kernel releases is down but not too bad, at least for this particular Haswell system. On Skylake the 4.15 impact may be greater, but unfortunately the newer CPUs weren't as well supported if going quite far back in kernel history.

PostMark does take a more noticeable hit with Linux 4.15 and is at its lowest point since at least Linux 4.0.

With heavy user-space workloads that don't interact with the kernel much, the performance is largely flat going back to Linux 4.0 that was released in April 2015.