Abstract
By allowing users to specify multiple execution versions of a task with different amounts of worst-case execution time and costs, this paper explores how to minimize of the overall system cost under the timing constraints for sporadic real-time tasks. One specific application is to minimize the requirement scratchpad memory size (system cost) to meet the timing constraint, while the worst-case execution time of a task depends on its allocated scratchpad memory size. This paper shows that the problem is NP-hard for approximation, if speed augmentation is not allowed.