The rest of the 6.3 merge window

Indeed, I only changed whitespace and basic formatting to please scripts/checkpatch.pl, to avoid impact on the measurements:
https://git.kernel.org/pub/scm/linux/kernel/git/geert/ren...
In theory, a synthetic benchmark can be optimized away entirely by a sufficiently smart compiler. That's also why the benchmark is split in two source files.

The figures cannot be compared accurately, as they depend heavily on compiler version and compiler options (some dictated by the kernel build system). They do work fine for my intended usage (verifying CPU core clock speeds), as DMIPS/MHz is reliable.

Typically, on e.g. arm32, I get 25% less DMIPS with the in-kernel version than with the userspace version (https://github.com/qris/dhrystone-deb.git).
Even with the latter, I saw differences up to 19% using gcc-4.9/6.3/7.4/8.3/9.3/10.2 (6.3 was worst, 10.2 was best).