@article{DeubzerMottokMargulletal., author = {Deubzer, Michael and Mottok, J{\"u}rgen and Margull, Ulrich and Niemetz, Michael and Wirrer, Gerhard}, title = {Efficient Scheduling of Reliable Automotive Multi-core Systems with PD² by Weakening ERfair Task System Requirements}, series = {Automotive Safety and Security}, journal = {Automotive Safety and Security}, pages = {53 -- 67}, abstract = {Partly Proportionate fair (Partly-Pfair) scheduling, which allows task migration at runtime and assigns each task processing time with regard to its weight, makes it possible to build highly efficient embedded multi-core systems. Due to its non-work-conserving behavior, which might leave the CPU idle even when tasks are ready to execute, tasks finish only shortly before their deadlines are reached. Benefits are lower task jitter, but additional workload, e.g. through interrupts, can lead to deadline violations. In this paper we present a work-conserving extension of Partly-Pfair scheduling, called PERfair scheduling and the algorithm P-ERfair-PD2 which applies Pfair modifications used for Partly-Pfair on the concept of ERfairness and PD2 policies. With a simulation based schedulability examination we show for multiple time base (MTB) task sets that P-ERfair- PD2 has the same performance as Partly-Pfair-PD2. Additionally, we show that P-ERfair- PD2 has a much higher robustness against perturbations, and therefore it is well suited for embedded domains, especially for the Automotive domain.}, language = {en} } @inproceedings{DeubzerMargullMottoketal., author = {Deubzer, Michael and Margull, Ulrich and Mottok, J{\"u}rgen and Niemetz, Michael and Wirrer, Gerhard}, title = {Partly Proportionate Fair Multiprocessor Scheduling of Heterogeneous Task Systems}, series = {5th Embedded Real Time Software and Systems Conference, May 2010}, booktitle = {5th Embedded Real Time Software and Systems Conference, May 2010}, abstract = {Proportionate fair (Pfair) scheduling, which allows task migration at runtime and assigns each task processing time with regard to its weight, is one of the most efficient group of SMP multiprocessor scheduling algorithms known up to now. Drawbacks are tight requirements to the task system, namely the restriction to periodic task systems with synchronized task activation, quantized task execution time, and implicit task deadline. Most likely, a typical embedded real-time system does not fulfill these requirements. In this paper we address violations of these requirements. For heterogeneous task systems, we define the multiple time base (MTB) task system, which is a less pessimistic model than sporadic task systems and is used for automotive systems. We apply the concept of Pfair scheduling to MTB task systems, called partly proportionate fair (Partly-Pfair) scheduling. The restrictions on MTB task systems required for Partly-Pfair ness are weaker than restrictions on periodic task systems required for Pfair ness. In a simulation based study we examined the performance of Partly-Pfair-PD and found it capable to schedule feasible MTB task sets causing a load of up to 100\% of the system capacity.}, language = {en} } @inproceedings{DeubzerMargullMottoketal., author = {Deubzer, Michael and Margull, Ulrich and Mottok, J{\"u}rgen and Niemetz, Michael and Wirrer, Gerhard}, title = {Partitionierungs-Scheduling von Automotive Restricted Tasksystemen auf Multiprozessorplattformen}, series = {Proceedings of the 2nd Embedded Software Engineering Congress, 8. bis 10. Dezember 2009, Sindelfingen}, booktitle = {Proceedings of the 2nd Embedded Software Engineering Congress, 8. bis 10. Dezember 2009, Sindelfingen}, pages = {536 -- 542}, language = {de} } @inproceedings{DeubzerHobelsbergerMottoketal., author = {Deubzer, Michael and Hobelsberger, Martin and Mottok, J{\"u}rgen and Schiller, Frank and Dumke, Reiner and Siegle, Markus and Margull, Ulrich and Niemetz, Michael and Wirrer, Gerhard}, title = {Modeling and Simulation of Embedded Real-Time Multi-Core Systems}, series = {Proceedings of the 3rd Embedded Software Engineering Congress, 7. bis 9. Dezember 2010, Sindelfingen}, booktitle = {Proceedings of the 3rd Embedded Software Engineering Congress, 7. bis 9. Dezember 2010, Sindelfingen}, language = {en} } @inproceedings{HobelsbergerDumkeMottoketal., author = {Hobelsberger, Martin and Dumke, Reiner and Mottok, J{\"u}rgen and Niemetz, Michael and Wirrer, Gerhard}, title = {An Experience-Based Repository of Reusable Components for an Component-Based Automotive Software System}, series = {Applied Software Measurement, proceedings of the joined International Conferences on Software Measurement IWSM/MetriKon/Mensura 2010, 10.-12. November 2010, Stuttgart, Germany}, booktitle = {Applied Software Measurement, proceedings of the joined International Conferences on Software Measurement IWSM/MetriKon/Mensura 2010, 10.-12. November 2010, Stuttgart, Germany}, pages = {218 -- 240}, language = {en} }