Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer of the following (any seven question
only):
A _____ process is moved to the ready state when its time quantum expires.
Which of the following is also called job scheduler?
Compaction is used to solve the problem of
Which process can be affected by other processes executing in the system?
What is the drawback of banker's algorithm?
An I/O port typically consists of four registers- status, control, _____ and _____ registers.
The address loaded into the memory address register of the memory is referred to as
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?
The Trap mode bit changes from 0 to 1 when _____ mode switches to _____ mode.
Waiting Time is calculated as
Q.2 Solve both questions :
Define Thread? List some of the benefits of multithreading. Demonstrate the three methods to implement Threads.
Assume the following workload in a system:
| Process | Arrival Time | Burst Time |
|---|---|---|
| P0 | 1 | 3 |
| P1 | 0 | 6 |
| P2 | 3 | 2 |
| P3 | 4 | 7 |
| P4 | 2 | 8 |
| P5 | 6 | 5 |
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
Q.3 Solve both questions :
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?
Q.4 Solve both questions :
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?
Q.5 Solve both questions :
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.
Q.6 Solve both questions :
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.
Q.7 Solve both questions :
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.
Q.8 Solve this question :
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
Q.9 Write short notes on any two of the following:-
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Q.1 Choose the correct answer of the following (any seven question
only):
A _____ process is moved to the ready state when its time quantum expires.
Which of the following is also called job scheduler?
Compaction is used to solve the problem of
Which process can be affected by other processes executing in the system?
What is the drawback of banker's algorithm?
An I/O port typically consists of four registers- status, control, _____ and _____ registers.
The address loaded into the memory address register of the memory is referred to as
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?
The Trap mode bit changes from 0 to 1 when _____ mode switches to _____ mode.
Waiting Time is calculated as
Q.2 Solve both questions :
Define Thread? List some of the benefits of multithreading. Demonstrate the three methods to implement Threads.
Assume the following workload in a system:
| Process | Arrival Time | Burst Time |
|---|---|---|
| P0 | 1 | 3 |
| P1 | 0 | 6 |
| P2 | 3 | 2 |
| P3 | 4 | 7 |
| P4 | 2 | 8 |
| P5 | 6 | 5 |
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
Q.3 Solve both questions :
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?
Q.4 Solve both questions :
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?
Q.5 Solve both questions :
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.
Q.6 Solve both questions :
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.
Q.7 Solve both questions :
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.
Q.8 Solve this question :
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
Q.9 Write short notes on any two of the following:-
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Questions
Choose the correct answer for any seven of the following :
A direct method of deadlock prevention is to prevent the occurrences of __________
__________ is the time required to move the disk arm to the required track.
A process stack does not contain:
A set of processes is deadlock if
When high priority task is indirectly pre-empted by medium priority task effectively inverting the relative priority of the two tasks, the scenario is called?
Which module gives control of the CPU to the process selected by the short-term scheduler?
The circular wait condition can be prevented by:
Run time mapping from virtual to physical address is done by:
Which algorithm chooses the page that has not been used for the longest period of time whenever the page required to be replaced?
The heads of the magnetic disk are attached to a .... that moves all the heads as a unit.
Answer the following:
If FIFO page replacement algorithm is used with 4 page frames and 8 pages, how many page faults will occur with reference string 0124720347 if four page frames are initially empty? Solve the same problem for LRU page replacement algorithm.
Define a process. Explain the process state transition with a neat diagram.
Answer the following:
What is PCB? Discuss its major fields.
Explain IPC Problem-Readers & Writers Problem?
Answer the following:
What is deadlock? List the conditions that lead to deadlock. How deadlock can be prevented.
Explain the use of Banker's algorithm for multiple resources for deadlock avoidance with illustration.
Answer the following:
Explain Linux kernel and its functions in brief.
Define operating system. Explain the different views of operating system. Also explain types of operating system.
Answer the following:
What is Semaphore? How can we achieve the synchronization using semaphore for producer-consumer problem?
Establish the necessity for memory management. Explain the memory management with the use of Linked Lists.
Answer the following:
Explain the classical thread model with its implementation strategies.
Discuss the Peterson's solution for the race condition with algorithm.
Answer the following:
What is RAID? Explain in brief.
What is I-node? Explain in detail.
Answer the following:
Explain the structure of a page table entry. If a machine has 48 bit virtual addresses and 32-bit physical addresses and pages are of 8 KB, how many entries are needed for the page table?
Define and explain following terms : (i) Authentication (ii) Mutual Exclusion (iii) Monitor (iv) Segmentation.
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
Questions
Choose the correct answer (any seven) :
Which of the following is a non-preemptive OS?
The CPU utilization is low when the system is
Which of the following is a part of FAT?
The available routing schemes are
Which of the following CPU scheduling algorithms will prevent starvation problem?
The problem of thrashing may be reduced by
The purpose of virtual memory system is to
A file system uses the contiguous space allocation mechanism for disk space allocation. For better utilization of disk space, this file system must use
CPU performance is based on
Answer the following:
What are the main purposes of an operating system?
In a multiprogramming and time-sharing environment several users share the system simultaneously. This situation can result in various security problems. (i) Explain any two such problems. (ii) Can we ensure the same degree of security in a time-shared machine as we have in dedicated machine? Explain your answer.
Answer the following:
What are the differences between user-level threads and kernel-level threads? Under what circumstances is one type better than the other?
What resources are used when a thread is created? How do they differ from those used when a process is created?
Describe the actions taken by a kernel to context switch between kernel-level threads.
Answer the following:
What is critical-section problem? How are semaphores helpful in solving this problem?
What is race condition? Explain Peterson's solution to mutual exclusion problem.
Explain the concept of transaction atomicity.
Answer the following:
State and explain the necessary and sufficient conditions for a deadlock.
Explain the issues with deadlock detection and resolution.
Answer the following:
What are the various allocation policies in variable partition multiprogramming? Explain the differences between internal and external fragmentations.
Consider a main memory with the capacity of 4 page frames. Assume that the pages of a process are referenced in the order as given below : 1, 3, 4, 4, 3, 2, 1, 7, 5, 6, 4, 2, 1, 2 Which of FIFO or LRU would be better in the case as a page replacement policy and why?
Answer the following:
What is the cause of thrashing? How does the system detect thrashing, and once detected what can the system do to eliminate it?
Consider the following page reference string : 1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6 How many page faults would occur from the following replacement algorithms, assuming 1, 2, 3, 4, 5, 6 or 7 frames? (i) LRU (ii) FIFO (iii) Optimal
Answer the following:
Consider a system that supports the strategies of contiguous, linked and indexed allocation. What criteria should be the used in deciding which strategy is best utilized for a particular file?
What are the structures used in file-system implementation? Explain.
Answer the following:
Is disk scheduling, other than FCFS scheduling, useful in a single-user environment? Explain your answer.
Suppose that a disk drive has 5000 cylinders, numbered 0 to 4999. The drive is currently serving a request at cylinder 143 and the previous request was at cylinder 125. The queue of pending requests in FIFO order is 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130. Starting from the current head position, what is the total distance (in cylinders) that the disk arm moves to satisfy all the pending requests for each of the following disk-scheduling algorithms? (i) SSTF (ii) SCAN (iii) C-SCAN