Yes, all the usual scaling issues, of course it assumes a compiler that doesn't spend all its time contending on one big lock or sitting in cache coherency beca

Yes, all the usual scaling issues, of course it assumes a compiler that doesn't spend all its time contending on one big lock or sitting in cache coherency because it's doing an atomic increment of a single shared counter. But once you have the hardware it becomes reasonable to spend time fixing those issues. They're not fundamentally hard, compilers are mostly semi-functional transforms over large data structures.