Approximation of Worst-Case Execution Time for Preemptive Multitasking Systems

The control system of many complex mechatronic products requires for each task the Worst Case Execution Time (WCET), which is needed for the scheduler's admission tests and subsequently limits a task's execution time during operation. If a task exceeds the WCET, this situation is detected and either a handler is invoked or control is transferred to a human operator. Such control systems usually support preemptive multitasking, and if an object-oriented programming language (e.g., Java, C++, Oberon) is used, then the system may also provide dynamic loading and unloading of software components (modules). Only modern, state-of-the art microprocessors can provide the necessary compute cycles, but this combination of features (preemption, dynamic un/loading of modules, advanced processors) creates unique challenges when estimating the WCET. Preemption makes it difficult to take the state of the caches and pipelines into account when determining the WCET, yet for modern processors,...

• Type: Conference
• Year: 2000
• Where: LCTRTS
• Authors: Matteo Corti, Roberto Brega, Thomas R. Gross
• Keywords: Control Systems, LCTRTS 2000, System Software, Task's Execution Time, Worst Case Execution Time