Page 80 - DCAP608_REAL TIME SYSTEMS

Unit 7: Commonly used Algorithm to Real-time Scheduling

Notes
Figure 7.6: EDF Algorithm

Source: ansari.szabist-isb.edu.pk/RTS/RTS0508.ppt

!
Caution LST is not optimal for scheduling jobs on more than one processor.

Self Assessment

State whether the following statements are True or False:
7. Effective Deadline with a successor is equal to its given deadline.
8. Priorities cannot be assigned to jobs according to their deadlines.

9. The later the deadline, the higher the priority. Such scheduling algorithm is called the
Earliest-Deadline-First (EDF) algorithms.
10. The priorities are based on the release times of jobs; the later the release time, the higher
the priority.
11. The EDF algorithm can produces a feasible schedule of a set J of jobs with arbitrary release
times and deadlines on a processor if and only if J has feasible schedules.
12. Any feasible schedule of J can be systematically transformed into an EDF schedule.



Case Study Real-Time Dynamic Voltage Scaling

his case study concerns the performance of real-time embedded systems under
dynamic voltage scaling schedulers. Dynamic voltage scaling is a technique used
Tto address the trade-off between the battery life and the performance of battery
powered processors.
Contd...

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