Correlation Analysis Techniques for Refining Execution Time Estimates of Real-Time Applications

Scheduling techniques based upon worst case execution times, as are commonly used in real-time applications, often result in severe underutilization of the processor resources since most tasks finish in much less time than their anticipated worst-case execution times. In this paper we describe techniques for identifying correlation among the executions of various statements within a program. We demonstrate how this information can be used to refine the estimate of remaining worst case execution time of a real-time task as the execution of the task progresses. Refined estimates can be used at run-time to achieve better utilization of the system and early failure detection and recovery. 1 Introduction The success of real-time application software depends on its ability to produce a functionally correct result within definite timing constraints. Hard realtime applications, especially embedded applications, interact with and influence the environment in which they execute. Consequently, ..