The swap partition is not organized like a filesystem; in particular, it allocates each
process memory segment as a contiguous set of blocks on the disk. Why
is this a good practice?
This is so the whole process can be swapped in and out via one (or at most two) disk requests. This reduces the time taken to swap the whole process in or out,
which improves performance.
One might ask why we can actually do this. The reason is that the swap partition is managed by the OS, and thus, can be itself defragmented to improve performance.