ABSTRACT
Response Time Analysis (RTA) is an exact schedulability test for any fixed-priority assignment scheme on single-processor systems. It allows prediction of the worst-case response time of each task, which depends on the interference due to the execution of higher-priority tasks. The worst-case execution time can be obtained by two distinct methods often used in combination: measurement and analysis. On the other side, analysis may produce a tight estimate of the worst-case execution time, but is more difficult to perform. It requires, in fact, an effective model of the processor (including pipelines, caches, memory, etc.) and sophisticated code analysis techniques. The chapter introduces RTA, a check for schedulability that allows a finer resolution in respect of the other utilization-based checks. It is worth noting that, even when RTA fails, the task set may be schedulable because RTA assumes that all the tasks are released at the same critical instant.
