Question 1)a) What are the essential conditions for deadlocks to occur? Describe different protocols to prevent deadlocks by ensuring that the Hold and Wait condition never occur.
b) Consider the following snapshot of a system:
Using the banker’s algorithm, If the request from process P1 arrives for (0,4,2,0), can the request be granted immediately ? Show all the calculations.
c) Differentiate the logical and physical address space.
d) What is external fragmentation? Discuss different ways of handling the problem of external fragmentation.
Question 2)a) Give the structure of a typical inverted page table and List out the advantages and disadvantages of Inverted page table structures.
b) Explain the paging in the Pentium architecture.
c) Explain the following page replacement algorithms:
i) Enhanced second chance
ii) LFU
d) what is meant by thrashing ? Explain the methods of controlling thrashing.
Question 3)a) Write a note on tree-structured directories.
b) on a disk with 1000 cylinders numbers 0 to 999, compute the number of tracks the disk arm must move to satisfy all the requests in the disk queue. Assume the last request serviced was at track 756 and the head is moving towards track 0. The queue in FIFO order contains requests for the following tracks:
811, 348, 153, 968, 407, 500. Perform the computation for the following disk scheduling algorithm.
i) SSTF
ii) SCAN
c) Write a note on program and system threats.
d) Describe the process scheduling in Linux operating system.