Comment by psykotic

I've only profiled fd on Windows but one thing that stood out was that it performed 2 stat syscalls per file via NtQueryInformationFile (that number should be 0 per file on Windows since stat metadata comes for free with NtQueryDirectoryFile from the directory enumeration). When I mentioned this finding on Twitter, someone confirmed that it's also doubling up the stat syscalls on Linux. But if the OP is actually trying to benchmark raw directory enumeration speed vs git ls-files, they should make sure they're benchmarking against something that's not making per-file stat calls at all.