操作系统选择题·四

1. Consider the following set of processes, the length of the CPU burst time given in milliseconds :

   Process	Burst time
   P1	6
   P2	8
   P3	7
   P4	3

   Assuming the above process being scheduled with the SJF scheduling algorithm :

   A. The waiting time for process P1 is 3ms

   B. The waiting time for process P1 is 0ms

   C. The waiting time for process P1 is 16ms

   D. The waiting time for process P1 is 9ms

   
   答案：A

2. Preemptive Shortest Job First scheduling is sometimes called :

   A. Fast SJF scheduling

   B. EDF scheduling – Earliest Deadline First

   C. HRRN scheduling – Highest Response Ratio Next

   D. SRTN scheduling – Shortest Remaining Time Next

   
   答案：D

3. An SJF algorithm is simply a priority algorithm where the priority is :

   A. the predicted next CPU burst

   B. the inverse of the predicted next CPU burst

   C. the current CPU burst

   D. anything the user wants

   
   答案：A

4. ‘Aging’ is :

   A. keeping track

   答案：D