Operating Systems - Dec 2011

Computer Engineering (Semester 5)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks. 1 (a) Explain various system calls with appropriate syntaxes(10 marks) 1 (b) Explain mutual exclusion. Also write note on Peterson?s algorithm.(10 marks) 2 (a) Explain Demand Paging.(10 marks) 2 (b) What are various disk scheduling algorithms? Explain each one in brief.(10 marks) 3 (a) Explain the page replacement policies. Implement LRU, OPT, FIFO for the following sequence: 0, 1, 2, 4, 3, 7, 1, 4, 2, 3. Also calculate hits and faults(10 marks) 3 (b) Write note on Buffering Techniques. (10 marks) 4 (a) What are preemptive and non-preemptive algorithms?(10 marks) 4 (b) Explain DMA in terms of system concurrency. What is its implication on hardware design? (10 marks) 5 (a) Write a note on File Access Methods. (10 marks) 5 (b)

Consider the following snapshot.

Answer the following questions:

1. What is the content of matrix need?
2. Is the system in safe state?
3. If process P1 arrives with a request of (4, 5, 3) can the request be granted?

Write Short notes on

7 (a) Race Condition(7 marks) 7 (b) VM Ware(7 marks) 7 (c) Monolithic Vs Micro Kernels.(7 marks)