Please do not take the numbers below at face value. I still expect an actual reply to my initial comment.
Per-call overhead:
C (baseline) - ~30 ns
Rust (unsafe) - ~30 ns
C# (P/Invoke) - ~30-50 ns
LuaJIT - ~30-50 ns
Go (cgo) - ~40-60 ns
Java (22, FFM) - ~40-70 ns
Java (JNI) - ~300-1000 ns
Perl (XS) - ~500-1000 ns
Python (ctypes) - ~10,000-30,000 ns
Common Lisp (SBCL) - ~500-1500 ns
Seems like Go is still fast enough as opposed to other programming languages with GC, so I am not sure it is fair to Go.