Hardware Reference
In-Depth Information
SOLUTIONS FOR CHAPTER 6
6.1
For any dynamic server we must have
U
p
+
U
s
≤
1; hence, considering that
U
p
=2
/
3, the maximum server utilization that can be assigned to a Dynamic
Sporadic Server is
U
s
=1
−
U
p
=1
/
3
.
The deadlines computed by the server for the aperiodic jobs result:
d
1
=
a
1
+
T
s
=7,
d
2
=
d
1
+
T
s
=13, and
d
3
=
a
3
+
T
s
=21. The resulting schedule
produced by EDF + DSS is illustrated in Figure 13.14.
6.2
τ
1
τ
2
0
2
4
6
8
10
12
14
16
18
20
22
24
3
1
1
d1
d2
d3
ape
+2
+2
+1
DSS
0
2
4
6
8
10
12
14
16
18
20
22
24
Figure 13.14
Schedule produced by EDF + DDS for the task set of Exercise 6.2.
6.3
The deadlines computed by the server for the aperiodic jobs are
d
1
=
a
1
+
C
1
/U
s
=10,
d
2
=
d
1
+
C
2
/U
s
=13, and
d
3
=
a
3
+
C
3
/U
s
=18. The
resulting schedule produced by EDF + TBS is illustrated in Figure 13.15.
τ
1
τ
2
0
2
4
6
8
10
12
14
16
18
20
22
24
TBS
3
1
1
d1
d2
d3
U = 1/3
0
2
4
6
8
10
12
14
16
18
20
22
24
Figure 13.15
Schedule produced by EDF + TBS for the task set of Exercise 6.3.
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