Analysis and Optimisation of Distributed Embedded Systems with Heterogeneous Scheduling Policies
PhD Thesis No. 1089, Dept. of Computer and Information Science, Linköping University, June 2007 (Opponent: Prof. Luis Almeida, Universidade de Aveiro, Campo Universitario, Aveiro, Portugal).
Prof. Luis Almeida, Universidade de Aveiro, Campo Universitario, Aveiro, Portugal
The growing amount and diversity of functions to be implemented by the current and future embedded applications (like for example, in automotive electronics) have shown that, in many cases, time-triggered and event-triggered functions have to coexist on the computing nodes and to interact over the communication infrastructure.
When time-triggered and event-triggered activities have to share the same processing node, a natural way for the execution support can be provided through a hierarchical scheduler. Similarly, when such heterogeneous applications are mapped over a distributed architecture, the communication infrastructure should allow for the message exchange in both time-triggered and event-triggered manner, in order to ensure a straightforward interconnection of heterogeneous functnt scheduling policies. Moreover, due to the distributed nature of the architecture, message delays are also taken into consideration during the timing analysis. Once the schedulability analysis has been provide, the entire system can be optimised by adjusting its configuration parameters. The entire optimisation is directed by the results from the timing analysis, with the goal taht in the end the timing constraints of the application are satisfied.
The analysis and design methodology proposed in the first part of the thesis is applied next on the particular cathegory of distributed systems that use FlexRay as a communication protocol. We start by providing a schedulability analysis for messages transmitted over a FlexRay bus, and then by proposing a bus access optimisation algorithm that aims at improving the timing properties of the entire system.
For all the problems that we investigated, we have carried out extensive experiments in order to measure the efficiency of the proposed solutions. The results have confirmed both the importance of the addressed aspects during system level design, and the applicability of our techniques for analysing and optimising the studied systems.
[P07] Traian Pop, "Analysis and Optimisation of Distributed Embedded Systems with Heterogeneous Scheduling Policies", PhD Thesis No. 1089, Dept. of Computer and Information Science, Linköping University, June 2007 (Opponent: Prof. Luis Almeida, Universidade de Aveiro, Campo Universitario, Aveiro, Portugal).