Hardware Reference
In-Depth Information
by Equation (8.8). So we have
S
1
=
B
1
=3
R
1
=
S
1
+
C
1
=3+2=5
≤
D
1
S
(0)
2
=
B
2
+
C
1
=5
B
2
+
5
T
1
+1
C
1
=5
S
(1)
2
=
R
2
=
S
2
+
C
2
=7
>D
2
.
Hence, the task set is not schedulable by non-preemptive RM, since
τ
2
misses
its deadline.
8.2
We first note that the task set is not feasible in fully preemptive mode, since
R
(0)
3
=
C
1
+
C
2
+
C
3
=9
C
3
+
9
T
1
C
1
+
9
T
2
C
2
=12
R
(1)
3
=
C
3
+
12
T
1
C
1
+
12
T
2
C
2
=15
>D
3
.
R
(2)
3
=
Therefore, the response time of a task
τ
i
cannot be restricted to its first job, but
has to be extended up to job
K
i
=
L
i
, where
L
i
is the longest Level-
i
Active
Period. Using Equations (8.1), (8.2), and (8.3), we get the following results:
T
i
B
i
L
i
K
i
τ
1
2
5
1
τ
2
2
8
1
τ
3
1
37
3
τ
4
0
38
1
For task
τ
1
we have
s
1
,
1
=
B
1
=2
f
1
,
1
=
s
1
,
1
+
C
1
=2+3=5
R
1
=
f
1
,
1
=5
≤
D
1
.
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