Thanks - yes I meant to mention, that statically linked (and stripped of symbols) I get 745k for the C hello world with gcc 7.2, so the gap isn't as big as all

Thanks - yes I meant to mention, that statically linked (and stripped of symbols) I get 745k for the C hello world with gcc 7.2, so the gap isn't as big as all that. I understand that shared libraries/dynamic linking is still a WIP for rust so it's not exactly a fair comparison yet. With a shared standard library you also get the benefit of having the RAM shared across multiple processes. The 145 byte example also not being a fair comparison, since you've left out the standard library! Obviously C can do that too, but it's pretty neat to see the progress rust is making. (anyway, I'm going off topic since we're discussing kernel programming here).