Operating System - B.Tech 4th Semester Examination, 2024

A _____ process is moved to the ready state when its time quantum expires.

1. Blocked
2. New
3. Running
4. Suspended

Which of the following is also called job scheduler?

1. DMA controller
2. Short-term scheduler
3. CPU scheduler
4. Long-term scheduler

Compaction is used to solve the problem of

1. External fragmentation
2. Internal fragmentation
3. both (i) and (ii)
4. None of these

Which process can be affected by other processes executing in the system?

1. Independent process
2. Co-operative process
3. Dependent Process
4. child process

What is the drawback of banker's algorithm?

1. in advance processes rarely know how much resource they will need
2. the number of processes changes as time progresses
3. resource once available can disappear
4. all of the mentioned

An I/O port typically consists of four registers- status, control, _____ and _____ registers.

1. system in, system out
2. flow in, flow out
3. data in, data out
4. input, output

The address loaded into the memory address register of the memory is referred to as

1. Physical address
2. IP address
3. Port address
4. Logical address

Consider a disk queue with requests for I/O to blocks on cylinders: 98, 183, 37, 122, 14, 124, 65, 67. Considering FCFS (first cum first served) scheduling, the total number of head movements is, if the disk head is initially at 53 is?

1. 600
2. 630
3. 620
4. 640

The Trap mode bit changes from 0 to 1 when _____ mode switches to _____ mode.

1. Kernel, User
2. User, User
3. Kernel, Kernel
4. User, Kernel

Waiting Time is calculated as

1. Turnaround Time - Burst Time
2. Turnaround Time - Arrival Time
3. Completion Time - Arrival Time
4. Completion Time - Burst Time

Define Thread? List some of the benefits of multithreading. Demonstrate the three methods to implement Threads.

Assume the following workload in a system:

Illustrating the execution of these job using Round Robin Scheduling algorithm calculate when given Time Quantum = 3:
(i) Average Turn Around Time
(ii) Average Waiting Time

Differentiate between:
(i) User level Thread and Kernel level Thread
(ii) Contiguous and Indexed allocation method
(iii) Preemptive scheduling and Non-preemptive scheduling

How is a process different from a program? With an example explain why Process synchronization is necessary in multiprocessing operating system?

Describe the techniques for recovery from deadlock? Explain briefly resource allocation graph with examples.

Consider a disk queue with requests for I/O to blocks on cylinders: 98, 183, 37, 122, 14, 124, 65, 67. Considering SSTF (shortest seek time first) scheduling, the total number of head movements is, if the disk head is initially at 53 is?

What is the difference between fixed partition and variable partition also explains the need of compaction.

What is virtual memory? How is it implemented? Explain TLB in virtual memory with neat diagram.

What is Reader-Writer problem? Explain how Semaphore is used to resolve the problem of process synchronization.

What is Belady's Anomaly? Why LRU and Optimal Page Replacement algorithm doesn't suffer from this problem.

Compare and contrast Deadlock Prevention and Deadlock Avoidance. Can a system be in a state that is neither deadlock nor safe? If so, give an example. If not, prove that all states are either deadlock or safe.

Consider the following page reference string: 3, 4, 2, 1, 5, 5, 6, 2, 1, 2, 3, 7, 6, 3, 3, 2, 1, 2, 3, 6. Compare the page faults occur for the following replacement algorithms using four frames? Assume, initially all the frames are empty.
(i) LRU replacement
(ii) FIFO Replacement