L5

Question 1

Deadline Monotonic

Answer 1

• shortest deadline has the highest priority
• ## D = T => Rate Monotonic is optimal

Question 2

EDF, Earliest Deadline First Scheduling

Answer 2

Configuration
- none, all scheduling desicions are made online

• task priority given by its relative deadline
• the task with the shortest deadline left executes first

Assumption similar to RM
- indipendent tasks
- deadline = period
- releasetime = start of period

Schedulability Condition
- IF D= T => U<=1
- IF D<T => Processor utilisation demand analysis

Question 3

Offline Scheduling

Answer 3

• created before system run-time
• can be pre-emptive or non-pre-emptive
• “ned-to-end” communication described by precedence graph
• non periodic events taken care of by periodic tasks