多级反馈队列调度算法

1.'quantum length' defines the length of time slice for queue2.(You'd better read the 'README-mlfq' before you try your best to finish this assignment of OS. In fact, the file has illustrated nearly anything.)
2.It's necessary to handle the starvation, which refers to the condition that excessive interactive jobs consume all the CPU time and long-running jobs will never receive CPU time. So 'boost' is introduced, which means all the jobs are moved to the topmost queue after some specific periods.
Reference:http://pages.cs.wisc.edu/~remzi/OSTEP/cpu-sched-mlfq.pdf
The PDF file showed above would be a good tutorial for you to understand MLFQ(multi-level feedback queue) better.

个队列（Q1,Q2....QN），其中各个队列对于处理机的优先级是不一样的，也就是说位于各个队列中的作业(进程)的优先级也是不一样的。一般来说，优先级Priority(Q1) > Priority(Q2) > ... > Priority(QN)。怎么讲，位于Q1中的任何一个作业(进程)都要比Q2中的任何一个作业(进程)相对于CPU的优先级要高（也就是说，Q1中的作业一定要比Q2中的作业先被处理机调度），依次类推其它的队列。
2、对于某个特定的队列来说，里

options quantum length for queue 2：设置两个调度序列
options boost 0：目前的优先队列为队列0
options stayAfterIO False:设置IO操作结束后不停留在队列中
options iobumpfalse:设置IO碰撞为非
priority N:优先等级
ticksleft M:借用信号
timeleft Q:执行的剩余时间