One unusual alternative in resource constrained systems is to segment stacks per region of code, not directly per thread. This allows threads with very small i

One unusual alternative in resource constrained systems is to segment stacks per region of code, not directly per thread. This allows threads with very small initial stacks to take turns temporarily reserving a larger stack for doing a rare complex operation. Outside of reserving the stack, it takes a handful of instructions to call and then return from the temporary stack.