Instruction Cache locking for real-time embedded systems with multi-tasks

Modern processors often provide cache locking capability which can be applied statically and dynamically to manage cache in a predictable manner. The selection of instructions to be locked in the instruction cache (I-Cache) has dramatic influence on the performance of multi-task real-time embedded systems. This paper focuses on using cache locking techniques on a shared I-Cache in a real-time embedded system with multi-tasks to minimize its worst-case utilization (WCU) which is one of the most important criteria for designing realtime embedded systems. We analyze the static and dynamic strategies to perform I-Cache locking and propose different algorithms which utilize the foreknowing information of the real-time embedded applications. Experiments show that the proposed algorithms can reduce WCU further compared to previous techniques. Design suggestions on which strategy should be utilized under different situations are also induced from the experimental results.