Suppose that two processes A and B share a page that is not in memory. If process A faults on the shared page, the page table entry for process A must be updated once the page is read into memory.
(a) Under what conditions should the page table update for process B be delayed even though the handling of process A's page fault will bring the shared page into memory? Explain.
(b) What is the potential cost of delaying the page table update?