Dr. rer. nat. Simon Schwarzer

Alumnus/Alumna

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Research Interests

Performance Engineering [2004- ]

The increasing complexity of modern communication systems and devices as well as the shorter product cycles force system developers to consider the performance of their products as early as possible. Therefore, performance aspects become more and more important in today's system design and should be considered during the whole development cycle.

 

Performance Engineering is a wholistic approach towards product design keeping performance issues to the front throughout the development cycle. In general, the developers add non-functional requirements to the functional system model. From experience and measurements of previous systems, the developers try to model the expected performance and demand of each individual system component after which the system can be analysed and compared to the requirements.

 

We look at this topic from two different sides. On the one hand, the performance aware modelling helps the developers to understand the impact of design choices already during the design phase. On the other hand, it is also necessary to be able to predict the run time of systems on future platforms. This holds especially for embedded devices where special purpose processors are tailored according to the developer's needs. Thus, the developers have to be aware which particular feature they would like to have in future platforms. In this case, it is helpful to see how new features behave before real hardware is produced.

 

As an industry-wide standard design language, the Unified Modelling Language (UML) provides means for annotating models with performance measures using the UML Profile for Schedulability, Performance, and Time (SPT-profile) and the new MARTE-profile. From those annotated system models, a performance model may be generated which is then used to analyse the system in order to identify performance bottlenecks as early as possible. Common performance models used for this purpose include queueing networks, Petri nets, or event-driven simulation, depending on the level of detail requested and available. Additionally, measurements using prototype implementations provide further insight that complements the analytical estimates gained from the earlier development steps.

 

SysML, Model-Driven-Architecture, and the upcoming UML profile for "Modeling and Analysis of Real-Time and Embedded systems" (MARTE) are going to introduce a significant help for the developers on this field.

 

On the platform side, we focused our research on trying to predict changes of widely used embedded platforms. The ARM microprocessor is the core of Texas Instruments' OMAP boards and as such used in many embedded systems (e.g. mobile phones, DVD players, routers etc.). In order to evaluate new hardware designs already during early stages of the product development process when prototype hardware is not yet available, it is important to understand the performance characteristics of ARM processors and of the whole platform on different levels of abstraction. One approach to achieve this is to use the execution trace of an existing application on an existing hardware platform and analyse the run time of this code trace on a model of a target hardware platform. If the application itself is well understood, i.e. timing and resource requirements are known, the processor model may focus on the mere timing of instructions, avoiding the need for a detailed functional emulation of the hardware platform. This greatly simplifies the implementation of the hardware model since an interpretation of the application code is not required. By allowing for a parametrisation of the model, new features or whole platform modifications can be analysed and their impact on the application can be understood.

List of Publications

2011

2009

  • Lukas Pustina, Simon Schwarzer, Michael Gerharz, Peter Martini, Volker Deichmann
    "A Practical Approach for Performance-Driven UML Modelling of Handheld Devices - A Case Study"
    Journal of Systems and Software, Volume 82, Issue 1, Special Issue: Software Performance - Modeling and Analysis January 2009
2008

  • Lukas Pustina, Simon Schwarzer, Peter Martini
    "Using Representative Intervals for Trace-Based Performance Analysis of Mobile Phone Use Cases "
    Proceedings of the 24th UK Performance Engineering Workshop
    UKPEW 2008, London, UK, July 3-4, 2008

  • Lukas Pustina, Simon Schwarzer, Peter Martini
    "A Methodology for Performance Predictions of Future ARM Systems Modelled in UML"
    Proceedings of the 2nd Annual IEEE International Systems Conference
    Syscon 2008, Montreal, Canada, April 7-10, 2008

  • Edmund Coersmeier, Sven Jaborek, Patrick Paul, Martin Bucker, Marc Hoffmann, Lukas Pustina, Simon Schwarzer, Felix Leder, Peter Martini
    "Multicore Processing for Object Recognition in Mobile Devices"
    Proceedings of the embedded world Conference 2008
    embedded world Conference 2008, Nürnberg, Germany, February 26-27, 2008

2007

  • Lukas Pustina, Simon Schwarzer, Michael Gerharz, Peter Martini, Volker Deichmann
    "Performance Evaluation of a DVB-H Enabled Mobile Device System Model"
    Proceedings of the 6th International Workshop on Software and Performance
    WOSP 2007, Buenos Aires, Argentina, February 5-8, 2007, pp. 164-171

2006

  • Lukas Pustina, Michael Gerharz, Peter Martini, Simon Schwarzer, Volker Deichmann
    "Performance Aware Design of Communication Systems"
    Proceedings of the 31st IEEE Conference on Local Computer Networks
    LCN 2006, Tampa, Florida, November 14-16, 2006, pp. 39-46