As discussed with Carsten Bauer on the Julia Slack, I try to follow the tutorial https://github.com/RRZE-HPC/likwid/wiki/Tutorial%3A-Empirical-Roofline-Model in Julia. However, operational intensities vary significantly between several runs.
I followed the Julia setup at https://juliaperf.github.io/LIKWID.jl/stable/marker/#Example. A slightly modified version below serves as MWE.