What is Demand Paging in Operating Systems?

Technical
Medium
Flipkart
54.3K views

This question explores a memory management technique where pages are loaded only when needed. It tests advanced OS knowledge.

Why Interviewers Ask This

Demand paging optimizes memory usage significantly. Interviewers want to ensure you understand page faults and lazy loading. This is critical for performance tuning.

How to Answer This Question

Define demand paging as loading pages into memory only when referenced. Explain the role of page faults. Discuss the benefit of not loading unused pages. Mention copy-on-write and swapping. Connect to virtual memory concepts.

Key Points to Cover

  • Lazy loading concept
  • Page fault handling
  • Efficiency benefits
  • Copy-on-write relation

Sample Answer

Demand paging is a memory management scheme where pages are loaded into physical memory only when a process references them. If a page is missing, a page fault occurs, triggering the OS to fetch it from disk. This approach avoids wasting memory on unused pages, improving efficiency. Copy-on-write further optimizes this by delaying copying until modification. It is a cornerstone of modern virtual memory systems.

Common Mistakes to Avoid

  • Confusing with pre-paging
  • Ignoring page faults
  • No efficiency discussion

Practice This Question with AI

Answer this question orally or via text and get instant AI-powered feedback on your response quality, structure, and delivery.

Start Practicing

Related Interview Questions

Browse all 118 Technical questionsBrowse all 81 Flipkart questions