Processen/Planning/assignments/Opgave1

Problem 3.5

Consider the state transition diagram of Figure 3.9b. Suppose that it is time for the OS to dispatch a process and that there are processes in both the Ready state and the Ready/Suspend state, and that at least one process in the Ready/Suspend state has higher scheduling priority than any of the processes in the Ready state.Two extreme policies are as follows: (1) Always dispatch from a process in the Ready state, to minimize swapping, and (2) always give preference to the highest-priority process, even though that may mean swapping when swapping is not necessary. Suggest an intermediate policy that tries to balance the concerns of priority and performance.

Problem 3.9

Figure 3.8b suggests that a process can only be in one Event queue at a time.

a. Is it possible that you would want to allow a process to wait on more than one event at the same time? Provide an example.

b. In that case, how would you modify the queuing structure of the figure to support this new feature?