Towards a Cache-aware Development of High Integrity Real-TimeSystems

The job description of caches is to speed up memory accesses in the average case. Their intrinsic unpredictability however can seriously hamper the practicality and trustworthiness of system analysis and validation. In effect, this conflict asks system designers to take side between best average-case performance and maximum assurance, since both can't be had. In this paper we study the I-cache predictability problem from a system-level perspective. We identify some sources of cache-related variability that can be addressed whilst considering the architectural specification of the system and thus at an early stage of development. We discuss an example of what we call a "cache-aware" software architecture and experimentally evaluate its effectiveness on a representative application.