[account42]

Not only are linked lists rare, they are also mainly useful exactly in situations where you cannot guarantee a (even mostly) linear allocation order.

[gpderetta]

the optimization could be vaguely interesting if you are implementing a lisp (or some other list heavy language) and don't want to perform too aggressive non-local optimizations to optimize the layout of lists.

[twoodfin]

As I recall, at least one of the Lisp machine Lisps used a bit in the cons pair to declare if the cdr (tail element) was immediately following.

EDIT: https://en.wikipedia.org/wiki/CDR_coding

[kevin_thibedeau]

Memory pools are commonly allocated in a contiguous block and sliced into nodes placed onto a free list. They will be sequential until the pattern of allocations mixes them up.

[kazinator]

Garbage collection is good at consolidating swaths of adjacent free objects into ordered allocation.

[saagarjha]

The point here is that this isn't guaranteed, it's that it is likely. And as the other commenters mention, it's likelier than you think.

[kazinator]

The Linux kernel is full of links, and so are many (probably most) C programs in the GNU/Linux userland.