Linux 3.9 To Linux 4.9 Kernel Benchmarks: Testing The 21 Last Kernels
The FFTW performance went up after Linux 3.12 and largely remained that way except for a regression on 4.7~4.8 that's corrected by Linux 4.9.
Barely any change for MAFFT.
Or John The Ripper wasn't impacted by the Linux kernel either.
For many computational workloads, the Linux kernel doesn't interfere.