Comment by duped

> It links to a .so file which reads the executable header, allocates memory, loads the program, gets it ready to run, and starts it. The program loader runs in user space and is unprivileged. This is probably the right way to do it.

aiui this is what exec does, the problem outlined here is the split between process creation (expensive, kernel space, has to be done each time even if spawning the same process "template" repeatedly) and loading (cheap and in userspace).