Operating Systems · CS Fundamentals
Operating Systems Notes for Interviews
OS interviews open with fundamentals — process vs thread, the four deadlock conditions, paging vs segmentation — then move into memory management (paging, virtual memory, page faults), process scheduling, deadlock detection and avoidance (Banker's Algorithm), and concurrency. The strongest signal an interviewer looks for beyond the opening definitions is whether you can reason about a concrete failure — why access pattern changes performance on a memory-mapped file, why a resource request should or shouldn't be granted — not whether you can recite one more definition. OS is Ediky's largest CS Fundamentals topic by question count for exactly that reason.
What to actually study
- Virtual memory & paging — demand paging, thrashing, and why access pattern changes performance
- Deadlocks — detection, avoidance (Banker's Algorithm), and whether a given resource state is safe
- CPU scheduling algorithms and their tradeoffs
- Memory hierarchy — cache levels and average memory access time calculations
- Classic anomalies — Belady's Anomaly and why "more resources" doesn't always mean "better"
Real questions from Ediky's OS bank
Actual question titles from Ediky's CS Fundamentals bank:
- "Sorting a 10GB File Through a 4GB RAM Window with mmap"
- "GATE-Style Banker's Safety Check — 5 Processes, 3 Resource Types"
- "Diagnosing a Page-Fault Regression After a FIFO Switch"
- "Compute the Average Memory Access Time After Adding an L2 [Cache]"
Two ways to study on Ediky
OS is Ediky's largest single topic in CS Fundamentals: 211 questions spanning beginner definitions through scenario and debugging style, plus a 32-lecture video course for the structured first pass through the material.
Practice OS scenario questions
211 Operating Systems questions in Ediky's CS Fundamentals bank — Ediky's largest single CS topic.
Open CS Fundamentals