Measurement-based cache representativeness on multipath programs

Abstract

Autonomous vehicles in embedded real-time systems increase critical-software size and complexity whose performance needs are covered with high-performance hardware features like caches, which however hampers obtaining WCET estimates that hold valid for all program execution paths. This requires assessing that all cache layouts have been properly factored in the WCET process. For measurement-based timing analysis, the most common analysis method, we provide a solution to achieve cache representativeness and full path coverage: we create a modified program for analysis purposes where cache impact is upper-bounded across any path, and derive the minimum number of runs required to capture in the test campaign cache layouts resulting in high execution times.