Hardware Reference
In-Depth Information
τ
1
τ
2
0
2 4
6
8 0
12
4 6
18
0 2 4
(a)
delay(1)
τ
1
deadline
miss
τ
2
0
2
4
6
8
10
12
14
16
18
20
22
24
(b)
Figure 2.27
Scheduling anomaly in the presence of a delay: two tasks are feasible without
delays (a), but a delay in
τ
1
causes a deadline miss in
τ
2
(b).
Exercises
2.1
Give the formal definition of a schedule, explaining the difference between
preemptive and non-preemptive scheduling.
2.2
Explain the difference between periodic and aperiodic tasks, and describe the
main timing parameters that can be defined for a real-time activity.
2.3
Describe a real-time application as a number of tasks with precedence relations,
and draw the corresponding precedence graph.
2.4
Discuss the difference between static and dynamic, online and off-line, optimal,
and heuristic scheduling algorithms.
Provide an example of domino effect, caused by the arrival of a task
J
∗
,ina
feasible set of three tasks.
2.5
Search WWH ::
Custom Search