SOLUTIONS TO THE EXERCISES - Hard Real-Time Computing Systems: Predictable Scheduling Algorithms and Applications - page 462

A B

C D

E F G

Figure 13.3 Precedence graph for Exercise 3.5.

C i r i r ∗ i d i d ∗ i

A

2 0 0 25 20

B 3 0 0 25 15

C 3 0 3 25 23

D 5 0 3 25 20

E 1 0 6 25 25

F 2 0 8 25 25

G 5 0 8 25 25

Table 13.3 Task set parameters modified by the Chetto and Chetto's algorithm.

SOLUTIONS FOR CHAPTER 4

4.1 The processor utilization factor of the task set is

2

6 + 2 8 + 2 12 =0 . 75

and considering that for three tasks the utilization least upper bound is

U =

U lub (3) = 3(2 1 / 3

− 1) 0 . 78

from the Liu and Layland test, since U U lub , we can conclude that the task

set is schedulable by RM, as shown in Figure 13.4.

≤