Scheduling

Assignment 1 Pnumber Arrival time Burst time P1 0 2 P2 2 1 P3 3 2 P4 4 3 P5 10 10 Answer the following questions (1 and 2) 1) What is the Schedule length of the following process.(used FCFS scheduling) a) 10 b) 16 c) 19 d) 20 2) With respect to the table given above, which of the following is False? a) The order of execution is same in FCFS and SRTF b) The average waiting time is same for FCFS and SJF c) The CPU idle time is 2 units d) None of these 3) Consider a set of process A, B, C, D arriving in the same order at time zero in the ready queue. Their burst times are 4, 1, 8, 1 respectively. Using Round Robin scheduling, with time slice of 1 unit. What is the time at which process A completes execution? a) 4 b) 5 c) 9 d) 12 4) The data structure best suitable for implementing Round Robin Scheduling is a) Stack b) Queue c) List d) Array 5) Consider three process P1, P2, and P3 with arrival time (0, 1, 3) and burst time (6 ,5,4) respectively, what is the order of completion in SJF and RR scheduling with time slice of 2 units a) SJF: P1 P3 P2 RR: P1 P2 P3 b) SJF: P1 P2 P3 RR: P1 P2 P3 c) SJF: P1 P2 P3 RR: P2 P1 P3 d) SJF: P1 P3 P2 RR: P1 P3 P2 6) What does Turn around time mean ? a) Time from the process enters the ready queue to the time it starts execution. b) The difference between the arrival time and the completion time of the process. c) Time taken from start to completion of I/O d) Time a process waits in the ready queue. 7) Let the base priority of a system be 130 and the nice value provided is -10. What is the time slice that the process gets in the O(1) scheduling algorithm? 8) Match the following a) O(n) scheduler 1)has 2 run queues to prevent starvation b) O(1) scheduler 2)Set based on priority of the process c) Time Slice of a process 3)is based on average sleeping time d) Dynamic Priority 4) Not scalable to large number of processes I. a-3, b-1 c-4, d-2 Ii a-3, b-4,c-1, d-3 Iii a-4, b-1, c-2, d-3 Iv a-4, b-3, c-2, d -1 9) A process is provided with a bonus of 4 in the O(1) scheduling algorithm. The dynamic priority of the process . 10) Which of the following scheduling algorithms is not preemptive? a) FCFS b) Round robin c) SRTF d) Ideal Fair scheduling 11) Consider 3 Process, arriving at time zero, with total execution time of 40, 50, 60 ms respectively. Each process spends the first 40% of execution time doing I/O operation and the next 60% time for computations. The scheduler uses FCFS scheduling. Assuming that all I/O operations are overlapped. How much time in ms the CPU is idle? a) 16 ms b) 24ms c) 60ms d) None of these 12) From the data given in Question 11, what is the average turn around time? a) 32 ms b) 48 ms c) 52 ms d) 72 ms 13) State if the following statement is True or False. A system can have more than one scheduling algorithm at a time 14) Preemption is i. forced deallocation of the CPU from a program which is executing on the CPU. ii. release of CPU by the program after completing its task. iii. forced allocation of CPU by a program to itself. iv. a program terminating itself due to detection of an error. 15) Shortest Remaining Time first algorithm is not practical a. Its time complexity is huge, which makes it unsuitable for real systems b. It requires knowledge of the burst time, which is not easy to predict a)True,True b)True,False c)False,True d)False,False