进程调度算法典型问题练习

进程调度算法典型问题练习


题目:假设一个系统中有5个进程,它们的到达时间和服务时间如表所示,忽
略I/O以及其他开销时间,若分别按FCFS,SPF,SRTF,HRRN,RR,FB(第i
级队列时间片2i-1)以及Preemptive FB(第i级队列时间片2i-1)调度算法进
行CPU调度,请给出各个进程的完成时间、周转时间、带权周转时间、
平均周转时间和平均带权周转时间

进程 到达时间 服务时间
A 0 3
B 2 6
C 4 4
D 6 5
E 8 2

解:甘特图,可以使用 cmd markdown 解析下面的代码

1
2
3
4
5
6
7
8
dateFormat SSS
title
section FCFS
A :t11, 0s, 3s
B :t12, after t11, 6s
C :t13, after t12, 4s
D :t14, after t13, 5s
E :t15, after t14, 2s
1
2
3
4
5
6
7
8
dateFormat SSS
title
section SPF
A :t21, 0s, 3s
B :t22, after t21, 6s
E :t23, after t22, 2s
C :t24, after t23, 4s
D :t25, after t24, 5s
1
2
3
4
5
6
7
8
9
dateFormat SSS
title
section SRTF
A :t31, 0s, 3s
B :t32, after t31, 1s
C :t33, after t32, 4s
E :t34, after t33, 2s
B :t35, after t34, 5s
D :t36, after t35, 5s
1
2
3
4
5
6
7
8
dateFormat SSS
title
section HRRN
A :t41, 0s, 3s
B :t42, after t41, 6s
C :t43, after t42, 4s
E :t44, after t43, 2s
D :t45, after t44, 5s
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
dateFormat SSS
title
section RR(队首优先,q = 1)
A :t51, 0s, 2s
B :t52, after t51, 1s
A :t53, after t52, 1s
B :t54, after t53, 1s
C :t55, after t54, 1s
B :t56, after t55, 1s
D :t57, after t56, 1s
C :t58, after t57, 1s
B :t59, after t58, 1s
E :t510, after t59, 1s
D :t511, after t510, 1s
C :t512, after t511, 1s
B :t513, after t512, 1s
E :t514, after t513, 1s
D :t515, after t514, 1s
C :t516, after t515, 1s
B :t517, after t516, 1s
C :t518, after t517, 2s
1
2
3
4
5
6
7
8
9
10
dateFormat SSS
title
section RR(队首优先,q = 4)
A :t61, 0s, 3s
B :t62, after t61, 4s
C :t63, after t62, 4s
D :t64, after t63, 4s
B :t65, after t64, 2s
E :t66, after t65, 2s
D :t67, after t66, 1s
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
dateFormat SSS
title
section RR(刚进来的进程优先,q = 1)
A :t71, 0s, 2s
B :t72, after t71, 1s
A :t73, after t72, 1s
C :t74, after t73, 1s
B :t75, after t74, 1s
D :t76, after t75, 1s
C :t77, after t76, 1s
E :t78, after t77, 1s
B :t79, after t78, 1s
D :t710, after t79, 1s
C :t711, after t710, 1s
E :t712, after t711, 1s
B :t713, after t712, 1s
D :t714, after t713, 1s
C :t715, after t714, 1s
B :t716, after t715, 1s
D :t717, after t716, 1s
B :t718, after t717, 1s
D :t719, after t718, 1s
1
2
3
4
5
6
7
8
9
10
dateFormat SSS
title
section RR(刚进来的进程优先,q = 4)
A :t81, 0s, 3s
B :t82, after t81, 4s
C :t83, after t82, 4s
D :t84, after t83, 4s
E :t85, after t84, 2s
B :t86, after t85, 2s
D :t87, after t86, 1s
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
dateFormat SSS
title
section FB(非抢占)
A :t91, 0s, 3s
B :t92, after t91, 1s
C :t93, after t92, 1s
B :t94, after t93, 2s
D :t95, after t94, 1s
E :t96, after t95, 1s
C :t97, after t96, 2s
D :t98, after t97, 2s
E :t99, after t98, 1s
B :t910, after t99, 3s
C :t911, after t910, 1s
D :t912, after t911, 2s
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
dateFormat SSS
title
section FB(抢占)
A :t101, 0s, 2s
B :t102, after t101, 1s
A :t103, after t102, 1s
C :t104, after t103, 1s
B :t105, after t104, 1s
D :t106, after t105, 1s
C :t107, after t106, 1s
E :t108, after t107, 1s
B :t109, after t108, 2s
D :t1010, after t109, 2s
C :t1011, after t1010, 2s
E :t1012, after t1011, 1s
B :t1013, after t1012, 2s
D :t1014, after t1013, 2s