Problem Background Motivation Design a task and bus scheduling tool that works with the automotive design process and captures the constraints that the automotive domain has. This project will explore metrics which can characterize the scalability and reusability of the distributed embedded system, and through solving a mixed integer quadratic programming to schedule functionality on a given architecture so that certain design constraints are satisfied. Problem Description Reusability and Scalability Problem Formulation Notation, Parameters and Variables Objective Function Constraints Initial Results November 18, 2004 Simple Case Study Wei Zheng Mentor ： Claudio Pinello Sri Kanajan Advisor ： Alberto Sangiovanni-Vincentelli Reusability and Scalability Time Triggered Scheduling of WCTT Left Slack Right Slack Starting time Finishing time Message: 5-tuple parameter variable Vector Message: 5-tuple parameter variable Vector WCET Release Time Period Idle time Starting time Finishing time Task: 6-tuple parameter variable Vector Task: 6-tuple parameter variable Vector Tasks data Dependency Hard Deadline must be satisfied Deadline is equal to Period Legacy tasks can be taken into account Multi-Rate System Allow preemption for Tasks Bus is modeled as a non- preemptive node Sw-Hw mapping is given Assumptions D 12_2D 34 D 12_1 T2_1 T2_2 T4 T1_2T3T1_1 Time Bus ECU2 ECU1 T5_1 T5_2 Idle [ ECU1, T5_2] Idle Time Data Slacks Slack[ D12_2, T2_2] Reusability Tolerate changes of Tasks’ WCET Tolerate changes of Data’ WCTT Maintains Bus Schedule Maintains non-involved ECU schedules Maintains involved ECU schedules without re-configuration Message left & Right slack Max Sum of all slacks Min Variance of all slacks Motivation Scalability Accommodate NEW tasks on legacy system Provide blocks of computation time for future computation intensive tasks Provide porosity in schedules to allow for future tasks with tight deadlines idle time distribution on ECU Evenly distribute idle time Implementation Approach The set of Tasks The set of ECU Task pair with data dependency running on the same ECU Task pair with data dependency running on different ECU Non-reachable task pair running on the same ECU The set of task pair running on the same ECU The set of task allocation for ECU otherwise if task i is not preempted by task j otherwise Data from i to task j precedes data from task k to l otherwise Idle time for task i Idle time for ECU k before the super period Reusability Scalability Jointly Reusability & Scalability T1 T4T3 functionality ECU2 ECU1 FlexRay architecture Mapping T5T5 T6T6 T2 Task graph expansion (in a SUPERperiod) T1 T3 T2 T1 T2 T4 T5T5 T5T5 T6 D 34 D 12_2 T2_2 T1_2 T4 T3 T2_1 T1_1 T5_1 D 12_1 Time Bus ECU2 ECU1 Scalable Schedule: Add New Task T5_2 T2_2 D 12_2 T1_2 T5_2 T4 T3 D 12_1 T2_1 T1_1 Time Bus ECU2 ECU1 T5_1 D 34 Minimize End to End Latency T2_2 D 12_2 T5_2 D 34 T4 T3 D 12_1 T2_1 T1_1 Time Bus ECU2 ECU1 T5_1 T1_2 Checking Schedulability D 34 D 12_2 T2_2 T1_2 T4 T3 T2_1 T1_1 Time Bus ECU2 ECU1 T5_1T5_2 D 12_1 Scalable Schedule D 34 T5_2 D 12_2 T2_2 T1_2 T4 T5_1 T3 T2_1 T1_1 Time Bus ECU2 ECU1 D 12_1 Reusable Schedule--- WCET Changes WCET Increase D 34 T5_2 D 12_2 T2_2 T1_2 T4 T5_1 T3 T2_1 T1_1 Time Bus ECU2 ECU1 D 12_1 Reusable Schedule D 34D 12_2 T2_2 T4 T1_2 T2_1 D 12_1 T3T1_1 Time Bus ECU2 ECU1 T5_1 T5_2 Jointly Considering Reusable and Scalable Describe the Metric Formula cost fn in AMPL Get Scheduling Result Evaluate Result w.r.t. Metrics Case study Automatic AMPL data file generation AMPL model with cost function and constraints AMPL solver Automatic Gant graph generation T2_2 D 12_2 T1_2 T5_2 T4 T3 D 12_1 T2_1 T1_1 Time Bus ECU2 ECU1 T5_1 D 34. Self-developed project infrastructure. Off-the-shelf project infrastructure Tool Infrastructure Release and Deadline Constraints Execution Time/Transmission Constraints Precedence Constraints Mutual Exclusion Constraints Idle Time Constraints