Exploring and Understanding Multicore Interference from Observable Factors

Multi-core processors bring a wide variety of challenges to the development, maintenance and certification of safety-critical systems. One of the key challenges is to understand how tasks sharing the processing resource affect one another, and to build an understanding of existing or new platforms. Industry reports that interference can lead to large variations in execution times which can lead to a wide variety of problems including timing overruns. To support performance improvements, debugging and timing analysis, a framework is presented in this paper for reliably establishing the interference patterns of tasks using simple contenders. These contenders systematically manipulate the shared resources so the effect on interferences can be understood and analysed. The approach relies on guided exploration of the interference space and existing performance monitoring infrastructure. It has been implemented on a Tricore AURIX platform to analyse the behaviour of multiple real and kernel applications.