PROCESSSES AND THREADS
1. What is an operating system?
2. What are the main purposes of an operating system?
3. What is the kernel?
4. What are batch systems/
5. What is graceful degradation?
6. What is the advantage of Multiprogramming?
7. What is an Interactive computer
8. Discuss the differences between symmetric and asymmetric multiprocessing.
9. What is spooling?
10. Differentiate tightly coupled systems and loosely coupled systems?
11. What is real time system?
12. Specify the critical factor to be strictly followed in real time systems.
13. What are multiprocessor systems & give their advantages?
14. What do you mean by Time
15. What is the purpose of system programs?
16. What are privileged instructions?
17. What do you mean by system calls?
18. Why is the Operating System viewed as a resource allocator & contro
19. What is a process?
20. What is process control block?
21. What is a process state and mention the various states of a process?
22. What are schedulers?
23. What are the use of job queues, ready queues and device queues?
24. Differentiate Long term scheduler from short term scheduler.
25. What is meant by context switch?
26. What is the use of inter process communication.
27. What is a thread?
28. What are the benefits of multithreaded programming?
29. Compare user threads and kernel threads.
30. What is the use of fork and exec system calls?
1. Explain the various types of computer systems.
2. Explain how protection is provided for the hardware resources by the
3. What are the system components of an operating system and explain
4. Explain how parameters can be passed to system calls?
5. Explain process state diagram and process control block.
6. List and discuss the various services provided by the operating System.
7. What are the various process scheduling concepts
8. Explain about interprocess communication.
9. Give an overview about threads.
10. Explain in detail about the threading issues
11. Explain in detail about virtual machine?
12. Briefly discuss about Pthread
PROCESS SCHEDULING AND SYNCHRONIZATION
1. Define CPU scheduling.
2. What is preemptive and nonpreemptive scheduling?
3. What is a Dispatcher?
4. What is dispatch latency?
5. What are the various scheduling criteria for CPU scheduling?
6. Define throughput?
7. What is turnaround time?
8. Define race condition.
9. What is critical section problem?
10. What are the requirements that a solution to the critical section
11. What is bounded waiting in critical section?
12. Define entry section and exit section.
13. Give two hardware instructions and their definitions which can be
14. What is semaphores?
15. Define busy waiting and spinlock.
16. Define deadlock.
17. What is the sequence in which resources may be utilized?
18. What are conditions under which a deadlock situation may arise?
19. What is a resource-allocation graph?
20. Define request edge and assignment edge.
21. What are the methods for handling deadlocks?
22. Define deadlock prevention.
23. Define deadlock avoidance.
24. What are a safe state and an unsafe state?
25. What is safe state ?Give the use of safe state in deadlock avoidance
26. What is banker’s algorithm?
1. Write about the various CPU scheduling algorithms.
2. What is critical section problem and explain two process solutions and multiple
3. Explain what semaphores are, their usage, implementation given to avoid busy
waiting and binary semaphores.
4. Write about critical regions and monitors.
5. Give a detailed description about deadlocks and its characterization
6. Explain about the methods used to prevent deadlocks
7. Explain the Banker’s algorithm for deadlock avoidance.
8. .Consider the following Snapshot of a system?
9. Allocation Max Available
A B C D A B C D A B C D
Po 0 0 1 2 0 0 1 2 1 5 2 0
P1 1 0 0 0 1 7 5 0
P2 1 3 5 4 2 3 5 6
P3 0 6 3 2 0 6 5 2
P4 0 0 1 4 0 6 5 6
Answer the following questions using the banker’s Algorithm:
a. What is the content of the matrix need?
b. Is the system is in safe state?
c. If the request from process P1 arrives for (0,4,2,0) can the request
be granted immediately?
10. Explain briefly about Readers/Writers problem in classical Synchronization
implement using critical section.
11. What is the use of monitors for resource allocation.
12. Write detailed explanation about Multiprocessor scheduling and Real Time
13. Consider the following set of processes ,with the length of the CPU-burst time
and the arrival time given milliseconds.
Process CPU Burst time Arrival time Priority
P1 6 0 2
P2 2 1 2
P3 3 1 4
P4 1 2 1
P5 2 2 3
1. Define logical address and physical address.
2. What is logical address space and physical address space?
3. What is the main function of the memory-management unit?
4. Define dynamic loading.
5. Define dynamic linking.
6. What are overlays?
7. Define swapping.
8. What do you mean by best fit and first fit?
9. What is virtual memory?
10. What is Demand paging?
11. Define lazy swapper.
12. Define effective access time.
13. Define secondary memory.
14. What are the advantages of having an inverted page table?
15. What is the translation look aside buffer?
16. What is the purpose of paging the page table?
17. What is thrashing?
18. Why paging is used?
19. What is segmentation ?
20. Why should we use virtual memory?
21. What is the basic approach of page replacement?
22. What are the various page replacement algorithms used for page replacement?
23. Define Page fault rate.
24. What are the major problems to implement demand paging?
25. What is a reference string?
26. How does the system detect thrashing?
1 .Given memory partitions of 100KB, 500KB, 200KB, 300KB, and 600KB.(in
order),how would each of the first-fit, best –fit, worst fit algorithms place
processes of 212KB,417KB,112KB, and 426KB(in order). Which
algorithm makethe most efficient use of memory
2. Explain about contiguous memory allocation. 3. Give the basic concepts about
4. Write about the techniques for structuring the page table.
5. Explain the basic concepts of segmentation.
6. Explain the various page replacement strategies.
7. Compare paging with segmentation.
8. Explain Demand paging.
9. i)Consider the following memory allocation at a point of time ‘t’: Assume the
total memory available is 2000K,out of which 400K is occupied by the
resident part of the OS.At this point of time a process P4 with a memory
requirement of 300K arrives.Can memory be allocated to the arriving process
if a contiguous memory allocation scheme is adopted? If yes discuss how?If
no,discuss the reasons and then state what technique can be adopted to
allocate memory t process P4?
10 .Explain the hardware support of the paging system.
1. What is a file?
2. List the various file attributes.
3. What are the various file operations?
4. What are the information associated with an open file?
5. What are the different accessing methods of a file?
6. What is Directory?
7. What are the operations that can be performed on a directory?
8. What are the most common schemes for defining the logical structure of a
9. Define UFD and MFD.
10. What is a path name?
11. What are the various layers of a file system?
12. What are the structures used in file-system implementation?
13. What are the functions of virtual file system (VFS)?
14. Define seek time and latency time.
15. What are the allocation methods of a disk space?
16. What are the advantages of Contiguous allocation?
17. What are the drawbacks of contiguous allocation of disk space?
18. What are the advantages of Linked allocation?
19. What are the disadvantages of linked allocation?
20. What are the advantages of Indexed allocation?
21. How can the index blocks be implemented in the indexed allocation scheme?
1. What are files and explain the access methods for files?
2. Explain the schemes for defining the logical structure of a directory.
3. Write notes about the protection strategies provided for files.
4. Explain the various file allocation technique.
5. Consider the following page reference string:
Calculate the number of page faults would occur for the following page
replacement algorithm with frame size of 4 and 5 .Remember that all frames are
Initially empty, so your first unique pages will all cost one fault each.
i) LRU ii) FIFO iii)Optimal
6. i) State the reasons for page fault .Then, discuss the various techniques for
handling page faults.
ii) What is the cause of thrashing, what can the system detect thrashing?
Once it detects thrashing, what can the system do to eliminate this problem?
7. i) Discuss in detail the following LRU approximation page replacement
algorithms with suitable illustration.
a) Additional reference bits algorithm
b) Second chance algorithm
c) Enhanced second chance algorithm
8. Explain the schemes for defining the logical structure of a directory.
1. Define rotational latency and disk bandwidth.
2. How free-space is managed using bit vector implementation?
3. Define buffering.
4. Define caching.
5. Define spooling.
6. What are the various disk-scheduling algorithms?
7. What is low-level formatting?
8. What is the use of boot block?
9. What is sector sparing?
1. Write about the kernel I/O subsystem.
2. Explain the various disk scheduling techniques
3. Explain the file system in Linux.
4. .Explain DMA mode of data transfer.
5. Explain the various access methods for files.
6. Discuss in detail about the following Disk scheduling algorithm FCFS,
SSTF, SCAN, C-SCAN, C-Look
7. Explain in detail about disk management.
8. Explain in detail about swap space management.
9. Suppose that the 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 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
i)FCFS ii)C-SCAN iii)C-LOOK iv)Compare the results and give
10. Explain various RAID levels.(16)