21CS44 Dayananda Sagar University • Computer Science & Engineering (Semester 4)

Operating Systems

💡 DSU Exam Strategy & Guidance

CPU Scheduling (Round Robin, SRTF), Process Synchronization (Semaphores, Dining Philosophers), Deadlock (Banker’s Algorithm), and Virtual Memory (Page replacement: FIFO, LRU, Optimal).

High-Yield Passing Strategy: Banker’s Safety algorithm calculations and Gantt chart scheduling numericals are guaranteed.
Most Repeated Question Topics:
Banker’s Deadlock Avoidance AlgorithmLRU and Optimal Page Replacement CalculationsClassical IPC Problems (Producer-Consumer, Reader-Writer)Process State Transition Diagram & PCB

🔥 Most Predictable Exam Questions (2)

Guaranteed Every Year 8 Marks Module 3: Deadlocks

Q1. Consider 5 processes P0 to P4 with Allocation, Max matrices, and Available resources [3, 3, 2] for resources (A, B, C). Compute the Need Matrix and verify if the system is in a Safe State using Banker’s Algorithm. List the safe sequence.

Key Points: Need = Max - Allocation. Check process where Need <= Available, allocate and reclaim: Available += Allocation. Valid safe sequence: .

95% Probability 8 Marks Module 4: Virtual Memory Management

Q2. For the reference string: [7, 0, 1, 2, 0, 3, 0, 4, 2, 3, 0, 3, 2, 1, 2, 0, 1, 7, 0, 1] with 3 physical frames, compute the number of page faults using: (i) FIFO, (ii) LRU, and (iii) Optimal Page Replacement.

Key Points: Draw frame allocation table at each memory access. FIFO faults = 15, LRU faults = 12, Optimal faults = 9.

🎓 Open Source Courses & Video Playlists (3)

YouTube (Gate Smashers)

Gate Smashers: Operating Systems Full Course

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MIT OpenCourseWare

MIT 6.S081: Operating System Engineering

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YouTube (Neso Academy)

Neso Academy: Operating Systems Concepts

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📄 Previous Year Question Papers (2)

END_SEM • 2024

End Semester Exam 2024

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END_SEM • 2023

End Semester Exam 2023

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