1. Describe demand paging and how it affects system performance.
Difficulty: HardType: SubjectiveTopic: Virtual Memory
Demand paging is a technique where the operating system loads a page into physical memory only when it is needed (that is, when a page fault occurs). This reduces the initial load time of processes and lowers memory usage because only required pages are brought in. However frequent page faults can degrade performance significantly, because loading pages from disk is slow. Too many page faults may lead to thrashing. When designing systems and answering interview questions you should mention trade-offs: reduced memory footprint vs potential high page-fault overhead. :contentReference[oaicite:5]{index=5}