Hardware Reference
In-Depth Information
τ
1
τ
2
0
2
4
6
8
10
12
14
16
18
20
22
24
3
1
1
ape
PS
0
2
4
6
8
10
12
14
16
18
20
22
24
Figure 13.10
Schedule produced by Rate Monotonic and Polling Server for the task set
of Exercise 5.3.
τ
1
τ
2
0
2
4
6
8
10
12
14
16
18
20
22
24
3
1
1
ape
+2
+2
+1
SS
0
2
4
6
8
10
12
14
16
18
20
22
24
Figure 13.11
Schedule produced by Rate Monotonic and Sporadic Server for the task set
of Exercise 5.4.
5.4
A Sporadic Server can be guaranteed with the same method used for the Polling
Server. So, using the same parameters computed before (
C
s
=2and
T
s
=6)
we have the schedule shown in Figure 13.11.
5.5
Applying Equation (5.15) to the considered task set, we see that the maximum
utilization that can be assigned to a Deferrable Server to guarantee the periodic
task set is
U
s
max
=1
/
4. So, by setting
T
s
=4(maximum priority) and
C
s
=1, we satisfy the constraints.
The resulting schedule is illustrated in
Figure 13.12.
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