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ECE Back to Basics Colloquium with Björn Andersson, CISTER

ECE Back to Basics Colloquium
Wednesday November 11 by Björn Andersson, CISTER.

Title: Real-Time Scheduling on Multicores

This talk will start at 13:00 in I-105, FEUP. Lunch will start at 12:30.

Embedded computer systems is an important scientific area today as witnessed by three facts. First, 99% of all processors sold are used in embedded computer systems. Second, we, humans, interact with embedded computer systems daily and they are present in most business processes/operations. Embedded computer systems are already used in all moderns cars and aircrafts and they are routinely used in manufacturing systems and process industry. Third, the number of engineers working on embedded systems in Europe exceeds the number of lawyers in Europe.

The design of an embedded computer system typically requires domain knowledge (for example designing software for controlling a combustion engine requires knowledge of combustion engines) and knowledge about computers in general (programming, algorithms and data structures, computer architecture, etc.). But embedded computers tend to also bring their own special challenges. One of them, is to ensure that the computer does its thing at the right time (for example, take a sample at the right time or start the ignition in an engine at the right time or decompressing a video frame at the right time.). The scientific community has created algorithms and theories for scheduling programs to perform actions at the right time. These theories have been successful; they are taught in undergraduate classes in real-time systems at most major universities world-wide (FEUP included) and they have the remarkable feature that under certain assumptions, timing guarantees can be given although the exact time when a program requests to execute is unknown. But most of these results do not extend to computers with more than one processor. This is unfortunate since multicores are today becoming standard building blocks in system design. In fact, it is expected that 40% of all embedded computer systems will use multicore processors in 2011.

Therefore, real-time scheduling on multicores is currently the hot topic in the scientific area of real-time systems. I will sketch some results that have been obtained in this area and in particular some of my contributions. I will present a few important and simple equations and a few observations on scheduling algorithms and their performance but I will omit most of the details.

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