OS & Hardware
What is the role of a page table?
- AMapping virtual page numbers to physical page numbers
- BStoring a copy of the data in physical memory, page by page
- CManaging the priorities of running processes in page order
Show answer and explanation
Answer: A. Mapping virtual page numbers to physical page numbers
With virtual memory, the virtual addresses programs use are translated into actual physical memory addresses. A page table records, for each virtual page number, the corresponding physical page number and protection information such as read/write permissions; the OS builds one per process and the CPU's MMU walks it. Frequently used translations are cached in the TLB. It neither copies data contents nor manages process priorities.
- A. Correct. It maps virtual pages to physical pages.
- B. It does not store copies of data.
- C. Process priorities are managed by the scheduler.