There are costs to this, because you may dereference things that are not valid pointers either. The kernel used to have software prefetch code for linked list t

There are costs to this, because you may dereference things that are not valid pointers either. The kernel used to have software prefetch code for linked list traversal. On each access it would prefetch the subsequent access. Which sounds like a huge win. However, in practice the most common list size was just a few elements and there was a huge penalty for fetching the final, invalid null pointer. They ended up taking out the prefetching recently (and I think they saw a small speedup as a result!) Now maybe someone could invent a hardware prefetcher that does this in a way that's a net gain, but the fact that Intel hasn't done it yet suggests that it maybe it doesn't help much or that the situation isn't all that common.