OPERATING SYSTEM
ASSIGNMENT # 01
Q1. What three issues must be considered in the case preemption and explain?
Q2. Explain the differences in the degree to which the following scheduling
algorithms discriminate in favour of short processes:
 FCFS
 RR
 Multilevel feedback queues
Q3. Consider the following set of processes, with the length of the CPU burst
given in milliseconds:
Process
Burst Time
Priority
P1
20
4
P2
5
3
P3
8
1
P4
6
2
P5
10
4
The processes are assumed to have arrived in the order p1, p2, p3, p4, p5 all at
time 0.
(a) Draw the Gantt chart that illustrate the execution of these processes
using the following scheduling algorithms:
 FCFS
 SJF
 Round Robin with quantum = 3
(b) What is the turnaround of each process for each of the scheduling
algorithm in part (a)?
Q4. How can a system detect that some of its processes are starving?
Q5. How do I/O bound and CPU bound programs differ? Explain?
Q6. Explain counting and binary semaphores?
Q7. Explain the purpose of the checkpoint mechanism. How often should
checkpoints be performed? How does the frequency of checkpoints affect:
 System performance when no failure occurs?
 The time it takes to recover from a system crash?
 The time it takes to recover from a disk crash?
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