首页 > 试题广场 >

Under what circumstances is th

[问答题]

Under what circumstances is the rate monotonic scheduling inferior to earliest deadline first scheduling in meeting the deadlines associated

with processes?

推荐

Answer:Consider two processes P, and P2 where pi=50,lh=25and p2=75,f2=30.If I were assigned a higher priority than Pi,then the

following scheduling events happen under rate monotonic scheduling.P1 is scheduled att=0,P2is scheduled att=25,Ph is scheduled at

t=50,and P2 is scheduled att=75.P2 is not scheduled early enoughto meet its deadline.The earliest deadline schedule performs the fol-

lowing scheduling events:Pi is scheduled att=0,a is scheduled atf=25,P,is scheduled att=55,and so on.This schedule actually meets the deadlines and therefore earliest deadline first scheduling is more effective than the rate monotonic scheduler.


发表于 2018-05-05 21:01:22 回复(0)