UNIVERSITY OF HYDERABAD

DEPARTMENT OF COMPUTER AND INFORMATION SCIENCES


OPERATING SYSTEMS – QUIZ 3


  1. State one disadvantage of compile time binding.

  2. In contiguous allocation, how do we ensure that a process does not access memory belonging to some other process?

  3. What is the advantage gained by having a translation look-aside buffer?

  4. Two processes – P1 and P2 – require memory of 5MB and 6.3MB respectively. They use two modules – m1 and m2 – with memory requirements of 2MB and 3.5MB. What is the overall memory allocated to these two processes if we use static allocation versus dynamic allocation?

  5. What is the difference between internal and external fragmentation?

  6. Name two disadvantages of contiguous memory allocation.

  7. If a system has a 24-bit processor and uses a page size of 2KB, how many entries does the page table have? (8192)

  8. If a system has 512MB RAM with a page size of 4KB and the OS occupies 4MB of RAM, how many frames does the system have? (130048)

  9. State one advantage of segmentation over paging.

  10. What is the purpose of paging the page tables?

  11. What is Belady's anomaly?

  12. What is the condition that results in the thrashing of a system? (sum of all WS > frames)

  13. Give two solutions to the problem of thrashing. (Increase RAM, reduce degree of multiprogramming)

  14. Why is proportional allocation better than equal allocation when allocating frames?

  15. What can we say about the number of frames allocated to a process if local replacement strategy alone is used? (remains constant)

  16. Name two advantages gained by using virtual memory management. (phy. mem < size of program, degree of multiprogramming can be increased)

  17. For a system with a 32-bit processor and 8KB page size, how many pages are needed to hold the page table entries, assuming that each entry consists of the page number and its frame start address?

  18. What is the difference between demand paging and pure demand paging?

  19. How is a logical address in segmentation converted into a physical address?

  20. What will happen if the estimated working set size is greater than the actual working set of the processes?

  21. What method can be used to determine if a system is thrashing?