[理工] OS: CPU utilization和response time冲突

楼主: clonsey1314 (Clonsey)   2017-04-14 22:38:04
Discuss how the following pairs of scheduling criteria conflict in certain
settings.
(a) CPU utilization and response time
官方解答说:
"CPU utilization is increased if the overheads associatedwith context switching isminimized. The context switching
overheads could be lowered by performing context switches infrequently. This
could, however, result in increasing the response time for processes."
我知道context switch减少,CPU utilization会上升;
但不懂为何context switch减少会导致response time变长?
context switch减少,resonse time不是也会减少吗?
作者: kyuudonut (善良老百姓)   2017-04-14 22:49:00
"performing context switches infrequently"当然别人轮到的时间就久了
作者: krusnoopy (push)   2017-04-15 12:09:00
假设P1,P2,P3同时到,1ms跟2ms做一次context switching当然后者的utilization高,但response time长囉你可能以为是降低context swithing的时间吧但是题目假设context switching时间一样,只讨论频率
作者: s89162504 (阿本)   2017-04-15 16:42:00
先搞清楚response time的定义
作者: ken52011219 (呱)   2017-04-16 10:57:00
K大必推
楼主: clonsey1314 (Clonsey)   2017-04-16 16:22:00
谢谢大家的解释!

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