> The stack is definitely faster than anything else

I have seen it mentioned everywhere, but is this actually true?

I mean, of course it is faster than random cold memory, but is it actually faster than a hot, in-cache part of the heap? It is not special in any other way, AFAIK.

And for what it's worth, what pron mentioned, Java uses a pretty similar structure for initial allocation, a thread local buffer where you just pointer bump. Another thread can then in the background copy still alive objects from this "arena" and then reset the whole thing.