A TLB miss could happen when executing the next statement in your program. It's not something you have a lot of control over, and doesn't change the fact that allocating from the stack (when an option) is going to be faster than allocating from the heap.

So you don't allocate left and right, be it stack or heap.

It's all useless though unless you control the hardware. If you don't, you might as well prlimit --stack=unlimited and have at it.