@misc{RueckBierlLechneretal., author = {R{\"u}ck, Thomas and Bierl, Rudolf and Lechner, Alfred and Graf, Antonia and Dams, Florian and Schreiner, Rupert and Auchter, Eberhard and Kriz, Willy and Deubzer, MIchael and Schiller, Frank and Mottok, J{\"u}rgen and Niemetz, Michael and Margull, Ulrich and Hagel, Georg and Utesch, Matthias and Waldherr, Franz and B{\"o}hm, Matthias and Fraunhoffer, Judith and Gardeia, Armin and Schneider, Ralph and Streubel, Janet and Landes, Dieter and Studt, Reimer and Peuker, Dominik and Scharfenberg, Georg and Hook, Christian and Schuster, Dietwald and Ehrlich, Ingo and Dinnebier, Heinrich and Briem, Ulrich and L{\"a}mmlein, Stephan and Koder, Alexander and Bialek, Adam and Genewsky, Axel and Neumeier, Michael and Schlosser, Philipp and Rabl, Hans-Peter and Paule, Matthias and Galster, Christoph and Schiedermeier, Michael and Zwickel, Andreas and Hobmeier, Christoph and Bischoff, Tobias and Rill, Georg and Schaeffer, Thomas and Arbesmeier, Martin and Groß, Andreas and Schlegl, Thomas and Becker, Mark and Senn, Konrad and Schliekmann, Claus and Scholz, Peter and Sippl, Christian and Grill, Martin}, title = {Forschungsbericht 2011 / Hochschule f{\"u}r Angewandte Wissenschaften - Fachhochschule Regensburg}, editor = {Eckstein, Josef}, address = {Regensburg}, organization = {Hochschule f{\"u}r Angewandte Wissenschaften Regensburg}, issn = {1868-3533}, doi = {10.35096/othr/pub-732}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7321}, language = {de} } @misc{ScharfenbergMottokArtmannetal., author = {Scharfenberg, Georg and Mottok, J{\"u}rgen and Artmann, Christina and Hobelsberger, Martin and Paric, Ivan and Großmann, Benjamin and Pohlt, Clemens and Wackerbarth, Alena and Pausch, Uli and Heidrich, Christiane and Fadanelli, Martin and Elsner, Michael and P{\"o}cher, Daniel and Pittroff, Lenz and Beer, Stefan and Br{\"u}ckl, Oliver and Haslbeck, Matthias and Sterner, Michael and Thema, Martin and Muggenthaler, Nicole and Lenck, Thorsten and G{\"o}tz, Philipp and Eckert, Fabian and Deubzer, Michael and Stingl, Armin and Simsek, Erol and Kr{\"a}mer, Stefan and Großmann, Benjamin and Schlegl, Thomas and Niedersteiner, Sascha and Berlehner, Thomas and Joblin, Mitchell and Mauerer, Wolfgang and Apel, Sven and Siegmund, Janet and Riehle, Dirk and Weber, Joachim and Palm, Christoph and Zobel, Martin and Al-Falouji, Ghassan and Prestel, Dietmar and Scharfenberg, Georg and Mandl, Roland and Deinzer, Arnulf and Halang, W. and Margraf-Stiksrud, Jutta and Sick, Bernhard and Deinzer, Renate and Scherzinger, Stefanie and Klettke, Meike and St{\"o}rl, Uta and Wiech, Katharina and Kubata, Christoph and Sindersberger, Dirk and Monkman, Gareth J. and Dollinger, Markus and Dembianny, Sven and K{\"o}lbl, Andreas and Welker, Franz and Meier, Matthias and Thumann, Philipp and Swidergal, Krzysztof and Wagner, Marcus and Haug, Sonja and Vernim, Matthias and Seidenst{\"u}cker, Barbara and Weber, Karsten and Arsan, Christian and Schone, Reinhold and M{\"u}nder, Johannes and Schroll-Decker, Irmgard and Dillinger, Andrea Elisabeth and Fuchshofer, Rudolf and Monkman, Gareth J. and Shamonin (Chamonine), Mikhail and Geith, Markus A. and Koch, Fabian and {\"U}hlin, Christian and Schratzenstaller, Thomas and Saßmannshausen, Sean Patrick and Auchter, Eberhard and Kriz, Willy and Springer, Othmar and Thumann, Maria and Kusterle, Wolfgang and Obermeier, Andreas and Udalzow, Anton and Schmailzl, Anton and Hierl, Stefan and Langer, Christoph and Schreiner, Rupert}, title = {Forschungsbericht / Ostbayerische Technische Hochschule Regensburg}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-00-048589-3}, doi = {10.35096/othr/pub-1386}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-13867}, language = {de} } @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} } @article{DeubzerSchillerMottoketal., author = {Deubzer, Michael and Schiller, Frank and Mottok, J{\"u}rgen and Niemetz, Michael and Margull, Ulrich}, title = {Effizientes Multicore-Scheduling in Eingebetteten Systemen - Teil 2: Ein simulationsbasierter Ansatz zum Vergleich von Scheduling-Algorithmen}, series = {atp - Automatisierungstechnische Praxis}, volume = {52}, journal = {atp - Automatisierungstechnische Praxis}, number = {10}, abstract = {Eingebettete Systeme unterliegen neben den funktionalen Anforderungen besonders nichtfunktionalen Qualit{\"a}tsanforderungen wie Effizienz, Zuverl{\"a}ssigkeit und Echtzeitf{\"a}higkeit. Mit steigendem Bedarf an Rechenkapazit{\"a}t k{\"o}nnen bisherige Konzepte zur Leistungssteigerung von Singlecore-Systemen jedoch nicht mehr eingesetzt werden - der Umstieg auf Multicore-Systeme wird erforderlich. Im zweiten Teil dieser Arbeit wird ein simulationsbasierter Ansatz zum Vergleich von Multicore-Scheduling-Algorithmen vorgestellt, mit dem Algorithmen f{\"u}r Multicore-Systeme mit voller Migration und dynamischer Task-Priorit{\"a}t untersucht werden. Wir erweitern diesen Ansatz um ein Verfahren zur Untersuchung einer Tasksetmenge mit stochastisch beschriebenen Eigenschaften und vergleichen ihn mit den im Teil 1 beschriebenen Algorithmen BinPacking-EDF und P-ERfair-PD² f{\"u}r eine Gruppe von Automotive Powertrain Systemen.}, language = {de} } @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} } @article{DeubzerSchillerMottoketal., author = {Deubzer, Michael and Schiller, Frank and Mottok, J{\"u}rgen and Niemetz, Michael and Margull, Ulrich}, title = {Effizientes Multicore-Scheduling in Eingebetteten Systemen - Teil 1: Algorithmen f{\"u}r zuverl{\"a}ssige Echtzeitsysteme}, series = {atp - Automatisierungstechnische Praxis}, journal = {atp - Automatisierungstechnische Praxis}, number = {9}, pages = {60 -- 67}, abstract = {Eingebettete Systeme unterliegen neben den funktionalen Anforderungen besonders nicht funktionalen Qualit{\"a}tsanforderungen wie Effizienz, Zuverl{\"a}ssigkeit und Echtzeitf{\"a}higkeit. Mit steigendem Bedarf an Rechenkapazit{\"a}t k{\"o}nnen bisherige Konzepte zur Leistungssteigerung von Singlecore-Systemen jedoch nicht mehr eingesetzt werden - der Umstieg auf Multicore-Systeme wird erforderlich. Im ersten Teil dieser Arbeit werden eine m{\"o}gliche Prozessorarchitektur f{\"u}r zuk{\"u}nftige Automotive Multicore-Systeme und die Abstraktion der Software f{\"u}r diese Systeme vorgestellt. Nach einer Klassifkation von Multicore-Scheduling-Algorithmen pr{\"a}sentieren wir exemplarisch einen Algorithmus mit statischer Taskallokation und einen Algorithmus mit dynamischer Taskallokation. Bei beiden Algorithmen handelt es sich um eine {\"U}berf{\"u}hrung theoretisch behandelter Algorithmen auf Automotive Systeme.}, 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{SchmidhuberDeubzerMaderetal., author = {Schmidhuber, Stefan and Deubzer, Michael and Mader, Ralph and Niemetz, Michael and Mottok, J{\"u}rgen}, title = {Towards the Derivation of Guidelines for the Deployment of Real-Time Tasks on a Multicore Processor}, series = {4th International Symposium on Model-Based Safety and Assessment (IMBSA 2014), Munich, Germany, October 27-29, 2014, Proceedings}, booktitle = {4th International Symposium on Model-Based Safety and Assessment (IMBSA 2014), Munich, Germany, October 27-29, 2014, Proceedings}, publisher = {Springer}, address = {Munich}, isbn = {978-3-319-12213-7}, doi = {10.1007/978-3-319-12214-4_12}, pages = {152 -- 165}, abstract = {The deployment of automotive software on a multicore processor includes the task of mapping executables to cores. Given the number of possible solutions, integrators have to solve a complex problem. Considering multiple, often conflicting goals like minimizing task response times and memory consumption, complexity further increased with the advent of multicore processors. We present a model-based approach for deriving design rules supporting integrators with statically mapping tasks to a multicore ECU. First, an evolutionary algorithm is used to sample the design space. For each sample, a model-based analysis is performed, resulting in the required fitness values according to the system metric objectives. Finally, subsets of the sample population are used to derive deployment guidelines by evaluating similarities between highly ranked solutions. This reduces the number of solutions to be considered by the integrators by orders of magnitude. In a case-study, we demonstrate the developed approach on an artificial automotive engine management system.}, language = {en} } @inproceedings{DeubzerMottokFlugetal., author = {Deubzer, Michael and Mottok, J{\"u}rgen and Flug, Christian and Zeitler, Thomas}, title = {Profiling Performance Analyse von Embedded Real-Time System Architekturen}, series = {Embedded Software Engineering Kongress, Tagungsband ; 8. bis 10. Dezember 2008, Sindelfingen}, booktitle = {Embedded Software Engineering Kongress, Tagungsband ; 8. bis 10. Dezember 2008, Sindelfingen}, pages = {155 -- 167}, language = {en} } @inproceedings{LaloDeubzerSchmidhuberetal., author = {Lalo, Erjola and Deubzer, Michael and Schmidhuber, Stefan and Oklapi, Erna and Mottok, J{\"u}rgen}, title = {Task Priority Optimization in Real-Time Multi-Core Embedded Systems}, series = {4. Landshuter Symposium Mikrosystemtechnik, Mikrosystemtechnik als Schl{\"u}sseltechnologie der Systemintegration, Tagungsband zum Symposium 12./13. M{\"a}rz 2014, Hochschule Landshut}, booktitle = {4. Landshuter Symposium Mikrosystemtechnik, Mikrosystemtechnik als Schl{\"u}sseltechnologie der Systemintegration, Tagungsband zum Symposium 12./13. M{\"a}rz 2014, Hochschule Landshut}, address = {Landshut}, isbn = {978-3-9812696-5-9}, pages = {96 -- 109}, abstract = {The shift from single-core to multi-core processors in real-time embedded systems leads to communication based effects on timing such as inter-core communication delays and blocking times. Moreover, the complexity of the scheduling problem increases when multi-core processors are used. In priority-based-scheduling, a fixed priority assignment is used in order to enable predictable behavior of the system. Predictability means that the system has to be analyzable which allows the detection of problems coming from scheduling decisions. For fixed priority scheduling in multi-core real-time embedded systems, a proper task priority assignment has to be done in a way that the system has minimal effects on timing. In this paper, we present an approach for finding near-optimal solutions for task priority assignment and the preemption/cooperation problem. A genetic algorithm is hereby used to create priority assignment solutions. A timing simulator is used for evaluation of each solution regarding real-time properties, memory consumption and communication overhead. In a case study we demonstrate that the proposed approach performs better than well known and single-core optimal heuristics for relatively complex systems.}, language = {de} } @inproceedings{AlfransederDeubzerJustusetal., author = {Alfranseder, Martin and Deubzer, Michael and Justus, Benjamin and Mottok, J{\"u}rgen and Siemers, Christian}, title = {An Efficient Spin-Lock Based Multi-Core Resource Sharing Protocol}, series = {33rd IEEE International Performance, Computing, and Communications Conference (IPCCC), Austin (TX), USA, 5-7 December 2014}, booktitle = {33rd IEEE International Performance, Computing, and Communications Conference (IPCCC), Austin (TX), USA, 5-7 December 2014}, doi = {10.1109/PCCC.2014.7017090}, abstract = {We present in this paper a new lock-based resource sharing protocol PWLP (Preemptable Waiting Locking Protocol) for embedded multi-core processors. It is based on the busy-wait model and works with non-preemptive critical sections while task may be preempted by tasks with a higher priority when waiting for resources. Our protocol can be applied in partitioned as well as global scheduling scenarios, in which task-fix, job-fix or dynamically assigned priorities may be used. Furthermore, the PWLP permits nested requests to shared resources. Finally, we present a case study based on event-based simulations in which the FMLP (Flexible Multiprocessor Locking Protocol) and the proposed PWLP are compared.}, language = {en} } @inproceedings{HelmDeubzerMottok, author = {Helm, C. and Deubzer, Michael and Mottok, J{\"u}rgen}, title = {Analyse der Echtzeiteigenschaften von Multicore Speicherarchitekturen in Eingebetteten Systemen mittels einer konfigurierbaren Simulationssoftware}, series = {4. Landshuter Symposium Mikrosystemtechnik : Mikrosystemtechnik als Schl{\"u}sseltechnologie der Systemintegration, Tagungsband zum Symposium 12./13. M{\"a}rz 2014, Hochschule Landshut}, booktitle = {4. Landshuter Symposium Mikrosystemtechnik : Mikrosystemtechnik als Schl{\"u}sseltechnologie der Systemintegration, Tagungsband zum Symposium 12./13. M{\"a}rz 2014, Hochschule Landshut}, editor = {Ivanov, Artem and Bicker, Marc and Patzelt, Peter}, address = {Landshut}, isbn = {978-3-9812696-5-9}, pages = {109 -- 117}, language = {de} } @inproceedings{LaloSchmidhuberDeubzeretal., author = {Lalo, Erjola and Schmidhuber, Stefan and Deubzer, Michael and Mottok, J{\"u}rgen}, title = {Extended Task Priority and Preemptability Optimization in Real-Time Multi-Core Embedded Systems}, series = {4th Applied Research Conference, 5th July 2014, Ingolstadt}, booktitle = {4th Applied Research Conference, 5th July 2014, Ingolstadt}, address = {Ingolstadt}, isbn = {978-3-8440-2875-1}, pages = {90 -- 95}, language = {en} } @inproceedings{MottokKraemerDeubzeretal., author = {Mottok, J{\"u}rgen and Kr{\"a}mer, Stefan and Deubzer, Michael and Hobelsberger, Martin and Martin, Felix}, title = {Hardware Based Tracing of Embedded Multi-Core Systems}, series = {4th Applied Research Conference, 5th July 2014, Ingolstadt}, booktitle = {4th Applied Research Conference, 5th July 2014, Ingolstadt}, isbn = {978-3-8440-2875-1}, language = {en} } @inproceedings{SailerSchmidhuberDeubzeretal., author = {Sailer, Andreas and Schmidhuber, Stefan and Deubzer, Michael and Alfranseder, Martin and Mucha, Matthias and Mottok, J{\"u}rgen}, title = {Optimizing the task allocation step for multi-core processors within autosar}, series = {2013 International Conference on Applied Electronics, IEEE, Pilsen, Czech Republic}, booktitle = {2013 International Conference on Applied Electronics, IEEE, Pilsen, Czech Republic}, abstract = {We present a model-based optimization approach for the task allocation problem in embedded multi-core systems. The information therefore is obtained from a system description in AUTOSAR and runtime measurements of the runnables in hardware traces. Based on this an initial software partitioning of runnables to tasks is created. We then use a genetic algorithm to create and evaluate solutions to the task allocation problem. Each solution is hereby evaluated using a discrete event-based simulation, which allows the evaluation with regard to real-time properties, resource consumption and data-communication overhead. The significance of our approach is then shown in a case-study. There, we optimize the task allocation of an embedded system, whose complexity is comparable to that of an actual system, on a multi-core processor. Finally, the results of the optimization are transferred to an ECU Configuration Description to enable further development in compliance with the AUTOSAR methodology.}, language = {en} } @inproceedings{SailerSchmidhuberDeubzeretal., author = {Sailer, Andreas and Schmidhuber, Stefan and Deubzer, Michael and Mottok, J{\"u}rgen}, title = {Amalthea - Plattform f{\"u}r kontinuierliche, modellbasierte Entwicklung}, series = {Tagungsband, 6th Embedded Software Engineering, Kongress 2013, 2. bis 6. Dezember 2013, Sindelfingen}, booktitle = {Tagungsband, 6th Embedded Software Engineering, Kongress 2013, 2. bis 6. Dezember 2013, Sindelfingen}, pages = {538 -- 544}, language = {de} } @inproceedings{MuchaMottokDeubzer, author = {Mucha, Matthias and Mottok, J{\"u}rgen and Deubzer, Michael}, title = {Probabilistic worst case response time estimation for multi-core real-time systems}, series = {2015 4th Mediterranean Conference on Embedded Computing (MECO), 14-18 June 2015, Budva, Montenegro}, booktitle = {2015 4th Mediterranean Conference on Embedded Computing (MECO), 14-18 June 2015, Budva, Montenegro}, pages = {31 -- 36}, abstract = {Traditional methods rely on Static Timing Analysis techniques to compute the Worst Case Response Time for tasks in real-time systems. Multi-Core real-time systems are faced up with concurrent task executions, semaphore accesses, and task migrations where it may be difficult to obtain the worst case upper bound. A new three staged probabilistic estimation concept is presented. Worst Case Response Times are estimated for tasksets which consist of tasks with multiple time bases. The concept involves data generation with sample classification and sample size equalization, model fit and Worst Case Response Time estimation on the basis of extreme value distribution models. A Generalized Pareto Distribution model fit method which includes threshold detection and parameter estimation is also presented. Sample classification in combination with the new Generalized Pareto Distribution model fit method allows to estimate Worst Case Response Times with low pessimism ranges compared to estimation methods that uses the Generalized Pareto or the Gumbel max distribution without sample classification.}, language = {en} } @inproceedings{SailerDeubzerLuettgenetal., author = {Sailer, Andreas and Deubzer, Michael and L{\"u}ttgen, Gerald and Mottok, J{\"u}rgen}, title = {CoreTAna: A Trace Analyzer for Reverse Engineering Real-Time Software}, series = {IEEE 23rd International Conference on Software Analysis, Evolution, and Reengineering (SANER), March 14 to March 18 2016, Suita, Osaka, Japan}, booktitle = {IEEE 23rd International Conference on Software Analysis, Evolution, and Reengineering (SANER), March 14 to March 18 2016, Suita, Osaka, Japan}, doi = {10.1109/SANER.2016.36}, abstract = {With the availability of the AUTOSAR standard, model-driven methodologies are becoming established in theautomotive domain. However, the process of creating models ofexisting system components is often difficult and time consuming, especially when legacy code has to be re-used or informationabout the exact timing behavior is needed. In order to tackle thisreverse engineering problem, we present CoreTAna, a novel toolthat derives an AUTOSAR compliant model of a real-time systemfrom a dynamic analysis of its trace recordings. This paper givesan overview of CoreTAna's current features and discusses itsbenefits for reverse engineering.}, language = {en} } @article{DeubzerMottokBaerwald, author = {Deubzer, Michael and Mottok, J{\"u}rgen and B{\"a}rwald, Andreas}, title = {Dependability-Betrachtung von Multicore-Scheduling}, series = {HANSER Automotive}, journal = {HANSER Automotive}, number = {11}, pages = {24 -- 27}, abstract = {Der Embedded Markt stellt sich auf eine neue Herausforderung ein: denUmstieg von Singlecore- auf Multicore-Prozessorsysteme. Dabei soll dieUmsetzung der Norm ISO 26262 die Funktionale Sicherheit der elektri-schen und elektronischen Systeme im Kraftfahrzeug gew{\"a}hrleisten. In diesem Beitrag betrachten die Hochschule Regensburg und die T{\"U}V S{\"u}dAutomotive GmbH das Scheduling eines Echtzeitsystems als ein sicher-heitsrelevantes Sub-System.}, language = {de} }