@caronte Let's try some more VFS benchmarks. This time with a hot cache, so filesystem shouldn't matter much. Still btrfs on the Linux side:

ls -alR linux-6.3.3 > /dev/null
Linux: 0.26, macOS 1.00

Linux is 4 times faster at enumerating/stat()ing files.

time tar cf /dev/null linux-6.3.3
Linux 0.55, macOS 2.7

Linux is 5 times faster than macOS at reading a full Linux kernel tree from page cache.

Seriously, the difference is that huge. And I had to use a tmpfs on Linux instead of /dev/null since otherwise GNU tar is smart enough to optimize the actual data copy away.