Workshop on Reconciling Performance with Predictability (RePP)

Offline guarantees for the satisfaction of critical constraints have to be derived by appropriate methods. The difficulty of deriving guarantees strongly depends on the predictability properties of the systems, in particular of the employed processor architecture, the software design discipline, the operating system including the scheduling strategy, the communication mechanism, and the used middleware. However, at the same time, system efficiency is measured by means of average-case behaviour under different criteria such as performance, utilization of resources, and power consumption.

Unfortunately, it can be observed that in computer system design the gap between average-case and worst-case behaviour increases rapidly. The technical reasons for the limited time-predictability are well known, for example the variation and non-determinism of the system environment and the interference caused by the use of shared resources.

The workshop will discuss approaches that atttack the combination of the two goals, the improvements of worst-case predictability and of average-case performance, on all system layers and in the layering principle itself. Predictable architectures, resource-aware compilers, scheduling considering worst-case and average-case performance will be considered. Of particular importance will be the abstraction mechanism used for structuring systems, which has to consider resources as first-class citizens.

Goals:

• Capture requirements of relevant application domains.
• Clarify the notion of Timing Predictability.
• Present existing approaches to reconciling predictability and performance.
• Investigate hardware and software design recommendations to allow for predictable multicore processors and timing predictable parallel software.

Participants:

• Researchers in safety-critical embedded systems.
• Safety-critical industry, e.g. aeronautics, automotive, defence.

Responsible: Lothar Thiele, Reinhard Wilhelm, Theo Ungerer, Bengt Jonsson, Jian-Jia Chen.

Supported by ARTISTDesign, PREDATOR, and MERASA.

The workshop is sponsored by the European Network of Excellence, ARTIST DESIGN, European projects PREDATOR and MERASA. The workshop will have presentations from invited experts in the related fields as well as contributions selected from submitted extended abstracts.

Your contribution should relate to the main subject of the workshop and the following list of questions:

• Which concepts and metrics do you see for characterizing Predictability?
• Computer science has been successful in removing resource interactions from interfaces. Does it make sense to enrich interfaces with resource-related information. If yes, on which level of abstraction (instruction set, software components, ...).
• Are there examples, where resource interactions have an influence accross abstraction layers? In particular, improvements on one layer lead to degradation on another.
• Are predictable systems only for a decreasing niche market?
• Will there be special hardware available in the future?
• Should one also follow main stream software development?
• Where are the applications where one needs to guarantee deadlines AND average performance is of interest?
• How can embedded multicore processors be designed in a time predictable fashion?
• How can embedded control algorithms that require a higher performance than sequential processors can deliver be parallelized and allow for time predictability of the parallel task?
• Is the execution of mixed real-time and non-real-time applications on an embedded multicore processor feasible?

No format is prescribed for the submission of abstract, but should be at most 4 pages. If accepted, you will have 20 minutes for presentation in the workshop and should provide a 6 page contribution in LLNCS style 3 weeks before the workshop so that we can prepare a condensation for the participants. The detail of paper submission will be announced later.

The above list of questions will be the base of a discussion forum among the invited participants. We expect you to prepare answers and present them at the workshop.

The collected contributions will be distributed at the workshop and possibly put online afterwards. We also intend to organize a special issue in one of the renowned journals in the field.

More information about the workshop can be found in RePP homepage http://www.tik.ee.ethz.ch/~jchen/RePP.

Important Dates:

• Submission of Abstract: 1st July, 15th July, 31rd July 2009
• Notification of Acceptance: 1st August 15th August 2009

Yours sincerely,

Lothar Thiele, Reinhard Wilhelm, Theo Ungerer, Bengt Jonsson, Jian-Jia Chen.

• Submission of Abstract: 1st July 15th July 2009
• Notification of Acceptance: 1st August 15th August 2009