WUCC: Joint WCET and Update Conscious Compilation for cyber-physical systems

The cyber-physical system (CPS) is a desirable computing platform for many industrial and scientific applications. However, the application of CPSs has two challenges: First, CPSs often include a number of sensor nodes. Update of preloaded code on remote sensor nodes powered by batteries is extremely energy-consuming. The code update issue in the energy sensitive CPS must be carefully considered; Second, CPSs are often real-time embedded systems with real-time properties. Worst-Case Execution Time (WCET) is one of the most important metrics in real-time system design. While existing works only consider one of these two challenges at a time, in this paper, a compiler-level optimization, Joint WCET and Update Conscious Compilation (WUCC), is proposed to jointly consider WCET and code update for cyber-physical systems. The novelty of the proposed approach is that the WCET problem and code update problem are considered concurrently such that a balanced solution with minimal WCET and minimal code difference can be achieved. The experimental results show that the proposed technique can minimize WCET and code difference effectively.