What is the primary purpose of multi-level paging?

• A. To speed up memory access by caching entire page tables.
• B. To eliminate the need for a TLB.
• C. To allow unlimited address space.
• D. To reduce the memory overhead of page tables by using a hierarchical structure.

Answer: (D)

Multi-level paging uses a hierarchy of page tables to map virtual addresses. Instead of one gigantic page table that lists every possible virtual page, the memory manager splits the mapping into levels: a directory points to page tables, which then point to the actual frames. This lets the system allocate page tables only for parts of the address space that are actually used, so the memory spent on page tables grows with real usage rather than with the size of the entire address space. That reduces the memory overhead needed to manage mappings, which is especially important for large or sparse address spaces. In practice, the TLB caches recent translations to keep lookups fast, so most accesses don’t require walking the full hierarchy. The other ideas don’t fit because caching entire page tables would still consume a lot of memory, the TLB is still needed, and multi-level paging doesn’t create unlimited address space.