BCS303 – OPERATING SYSTEMS (3rd SEM VTU) IMPORTANT NOTES FOR EXAM 1. CPU SCHEDULING • Preemptive vs Non-preemptive • Algorithms: - FCFS - SJF (Preemptive & Non-preemptive) - Priority - Round Robin • Gantt chart, Waiting time, Turnaround time. 2. PROCESS MANAGEMENT • Process states: New, Ready, Running, Waiting, Terminated • PCB includes: PID, PC, registers, memory info • Types of schedulers: Long-term, Medium-term, Short-term 3. PROCESS SYNCHRONIZATION • Critical section problem • Requirements: Mutual exclusion, Progress, Bounded waiting • Peterson’s solution • Semaphores: Binary & Counting • Producer–Consumer problem 4. DEADLOCK • Necessary conditions: Mutual exclusion, Hold & wait, No preemption, Circular wait • Methods: Prevention, Avoidance, Detection • Banker’s Algorithm 5. MEMORY MANAGEMENT • Paging (with diagram) • Segmentation • Logical → Physical address mapping • Page replacement algorithms: FIFO, LRU, Optimal 6. FILE SYSTEM • File allocation methods: - Contiguous - Linked - Indexed • Directory structures: Single, Two-level, Tree 7. DISK SCHEDULING • FCFS, SSTF, SCAN, CSCAN • Terms: Seek time, Latency, Transfer time STUDY THESE TOPICS TO GUARANTEE PASS.