[理工] 一題OS
Consider a system running ten I/O-bound tasks and one CPU-bound task.
Assume that the I/O-bound tasks issue an I/O operation once for every
millisecond of CPU computing and that each I/O operation takes 10 millisecond
to compute.Also assume that the context-switching overhead is 0.1 millisecond
and that all processes are long-running tasks.
Describe the CPU utilization for a round-robin scheduler when:
(a)The time quantum is 1 millisecond
(b)The time quantum is 10 milliseconds
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sol:
(a) 1.0/(1.0+0.1) = 1/1.1 = 91%
(b) 20/((10*1.1)+10.1) = 20/21.1 = 94%
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這題考滿多次的，可是就是沒有很了解怎麼解這題...
可以請高手詳細說明一下嗎?(尤其是(b)小題)
謝謝!!
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◆ From: 114.39.13.219
※ 編輯: boy5548 來自: 114.39.13.219 (01/28 13:29)
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