Publications on WCET-Aware Compilation

Title: Building Timing Predictable Embedded Systems.
Written by: Philip Axer, Rolf Ernst, Heiko Falk, Alain Girault, Daniel Grund, Nan Guan, Bengt Jonsson, Peter Marwedel, Jan Reineke, Christine Rochange, Maurice Sebastian, Reinhard von Hanxleden, Reinhard Wilhelm and Wang Yi
in: July (2012).
Volume: Number: (#2012-013),
on pages:
Series: 20120703-report-2012-013-axer.pdf
Address: Uppsala / Sweden
how published: 12-45 AEF+12 Uppsala
School: Uppsala University
Institution: Department of Information Technology
Type: Technical Report

Note: hfalk, ESD, tacle, WCC

Abstract: A large class of embedded systems is distinguished from general purpose computing systems by the need to satisfy strict requirements on timing, often under constraints on available resources. Predictable system design is concerned with the challenge of building systems for which timing requirements can be guaranteed a priori. Perhaps paradoxically, this problem has become more difficult by the introduction of performance-enhancing architectural elements, such as caches, pipelines, and multithreading, which introduce a large degree of nondeterminism and make guarantees harder to provide. The intention of this paper is to summarize current state-of-the-art in research concerning how to build predictable yet performant systems. We suggest precise definitions for the concept of "predictability", and present predictability concerns at different abstractions levels in embedded software design. First, we consider timing predictability of processor instruction sets. Thereafter, we consider how programming languages can be equipped with predictable timing semantics, covering both a language-based approach based on the synchronous paradigm, as well as an environment that provides timing semantics for a mainstream programming language (in this case C). We present techniques for achieving timing predictability on multicores. Finally we discuss how to handle predictability at the level of networked embedded systems, where randomly occurring errors must be considered.