CIS343|510
Chapter Nine Review(1-9) Identify these types of scheduling.
1. The decision to add to the number of processes that are partially or fully
in memory.
2. The decision as to which process’s pending I/O request shall be handled
by an available I/O device.
3. The decision as to which available process will be executed by the
processor.
4. The decision to add to the pool of processes to be executed.
5.
Job movement between Blocked, Suspend and Blocked.6.
Job movement between New and Ready, Suspend.7.
Job movement between Ready and Running.8.
Job movement between New and Ready.9.
Job movement between Ready, Suspend and Ready.10. The long-term scheduler controls the degree of ...
11. There are two decisions involved in long term scheduling. First, _____ to take on more processes.
12. Second, _____ processes to take on.
13. The short-term scheduler is also known as the _____.
14. The short-term scheduler is invoked whenever an event occurs that may
a.
b.
15. Give 4 examples of such events.
(16-22) Identify these short-term scheduling criteria.
16. The time from the submission of a request until the response begins to be
received.
17. The interval of time between the submission of a process and its
completion.
18. A given job should run in about the same amount of time and at about the
same cost regardless of the load on the system.
19. The scheduling policy should attempt to maximize the number of processes complete per unit of time.
20. The percentage of time that the processor is busy.
21. Processes should be treated the same and no process should suffer
starvation.
22. The scheduling policy should keep the resources of the system busy.
23. Which of these criteria are user-oriented?
24. Which of these criteria are system-oriented?
(25-31) Identify these scheduling policies.
25. Clock interrupts are generated at periodic intervals. When the interrupt
occurs the currently running process is placed in the ready queue and the
next ready job is selected on a first-come first-serve basis.
26. A non-preemptive policy in which the process with the shortest expected
processing time is selected next.
27. When the currently running process ceases to execute, the oldest process
in the ready queue is selected for running.
28. Use levels of FCFS queues (except that the lowest level one is Round
Robin). Each time a process returns to the Ready state, it is placed into
a lower level queue.
29. Choose the ready process with the greatest value of RR, where
RR = (w + s)/s, where
w = time spent waiting for the processor
s = expected service time
30. A preemptive version of SPN.
31. Without preempting the current process, choose that process which has
the shortest expected remaining processing time.
32. The ratio of turnaround time to actual service time is ...
(33-39) Which of the above scheduling policies...
33. ... are preemptive?
34. ... are non-preemptive?
35. ... penalizes short processes?
36. ... penalize long processes?
37. ... penalizes I/O bound processes?
38. ... may favor I/O bound processes?
39. ... may starve some processes?
40. What is time-slicing?
41.
Most scheduling algorithms treat the collection of ready processes as asingle pool from which to select the next running process. Alternatively,
processes could be viewed as being a set belonging to one or another
user. Then each user is assigned a weighting of some sort that defines
the user’s share of the system resources as a fraction of the total usage
of those resources. In particular each user is assigned a share of the
processor. This is known as ...