GATE CSE topic:operating-system PYQs & Answers — Page 7

Questions 61–65 of 65. Imported answers require independent review unless marked reviewed.

Consider the following CPU processes with arrival times (in milliseconds) and length of CPU bursts (in milliseconds) as given below:

Process	Arrival time	Burst time
P1	0	7
P2	3	3
P3	5	5
P4	6	2

If the pre-emptive shortest remaining time first scheduling algorithm is used to schedule the processes, then the average waiting time across all processes is __________ milliseconds.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A multithreaded program P executes with

number of threads and uses

number of locks for ensuring mutual exclusion while operating on shared memory locations. All locks in the program are non-reentrant, i.e., if a thread holds a lock

, then it cannot re-acquire lock

without releasing it. If a thread is unable to acquire a lock, it blocks until the lock becomes available. The minimum value of

and the minimum value of

together for which execution of P can result in a deadlock are:

Your answerChoose one option.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A system shares 9 tape drives. The current allocation and maximum requirement of tape drives for three processes are shown below:

Process	Current Allocation	Maximum Requirement
P1	3	7
P2	1	6
P3	3	5

Which of the following best describes current state of the system?

Your answerChoose one option.

Safe, Deadlocked

Safe, Not Deadlocked

Not Safe, Deadlocked

Not Safe, Not Deadlocked

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Recall that Belady’s anomaly is that the page-fault rate may increase as the number of allocated frames increases. Now, consider the following statements:

S1: Random page replacement algorithm (where a page chosen at random is replaced) suffers from Belady’s anomaly S2: LRU page replacement algorithm suffers from Belady’s anomaly

Which of the following is CORRECT?

Your answerChoose one option.

S1 is true, S2 is true

S1 is true, S2 is false

S1 is false, S2 is true

S1 is false, S2 is false

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Consider the set of processes with arrival time (in milliseconds), CPU burst time (in milliseconds), and priority (0 is the highest priority) shown below. None of the processes have I/O burst time.

Arrival Time	Burst Time	Priority
0	11	2
5	28	0
12	2	3
2	10	1
9	16	4

The average waiting time (in milliseconds) of all the processes using preemptive priority scheduling algorithm is __________.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

GATE CSE topic:operating-system PYQs

Question 24

Question 27

Question 33

Question 40

Question 51