Page 32 - slides.dvi

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•
•
•
If
–
If
–
–
–
–
Operating
First
i.e.
FCFS
Systems
case
—
Waiting
Waiting
Average
Average
three
processes
processes
First-Come
CPU
depends
P 1
poor
time
time
Process
times
on
arrive
arrive
waiting
waiting
for
for
due
Scheduling
in
in
as
0
0
to
order
Burst
the
the
time:
time:
25
P
3
P 1 =0;
good!
P 1 =11;
(0
First-Served
(11
Time
convoy
+
order
order
7
+
P
25
7
2
processes
P 3 ,
P 1 ,
P 2 =7;
P 2 =25;
P
1
+
+
11
P 2
effect.
P 2 ,
P 2 ,
Process
0)/3
arrive,
P 3 =0;
29)/3
P 3 :
P 1 :
P 3 =29;
=
Scheduling
=
e.g.
6.
Burst
4
18.
P
1
25
P
Time
2
29
P
3
P 3
Process
36
36
Burst
7
Time
28