Evaluating the Impact of Cache Coherency Interference on Multi-Core Safetycritical Applications

Cache coherency mechanisms are essential in multicore architectures to maintain consistency across distributed caches. However, in safety-critical systems-where predictable timing is paramount, these mechanisms can introduce unpredictable delays that undermine reliable performance. Central to this issue are snoop requests, generated as part of coherence traffic, which can stall task execution on individual cores. This paper investigates how snoop requests lead to observable interference, manifesting in heightened worst-case execution times (WCET) and average-case execution times (ACET). Our findings highlight the importance of recognizing coherence-induced delays when consolidating multiple safety-relevant functions on a single multi-core processor.