From Prof. Anthony D. Joseph

  1. Which of the following instructions should be allowed only in kernel mode?
    1. Disable all interrupts
    2. Read the time-of-day clock
    3. Set the time-of-day clock
  2. Five jobs are waiting to be run. Their expected running times are 9, 6, 3, 5, and X. In what order should they be run to minimize average response time? State the scheduling algorithm that should be used AND the order in which the jobs should be run. (Your answer will depend on X)
  3. Consider a system that starts with a total of 150 units of memory, which is then allocated to three processes as shown in the following table of processes, their maximum resource requirements, and their current allocations:
    Process    Max Demand    Currently Holds
    P1           70                  45
    P2           60                  40
    P3           60                  15
    P4           60

    Determine whether it would be safe to grant each ofthe following requests. If YES, give an execution order that could be guaranteed possible. If NO, show the resulting allocation table.

  4. Evaluate the Banker’s algorithm for its usefulness in real life. Give at least two reasons to justify your choice.