Pros and Cons of Paged Virtual Memory
Demand paging gives the OS flexibility to manage memory...
- programs may run with pages missing
unused or “cold” pages do not consume real memory
improves degree of multiprogramming
- program size is not limited by physical memory
program size may grow (e.g., stack and heap)
…but VM takes control away from the application.
- With traditional interfaces, the application cannot tell how much memory it has or how much a given reference costs.
- Fetching pages on demand may force the application to incur I/O stalls for many of its references.