Efficient Timing Isolation for Mixed-Criticality Communication Stacks in Performance Architectures

The high complexity of a network stack as found in Linux leads to unpredictable timing behavior and interference that is incompatible to safety standards. Inspired by the microkernel approach, a filter stack separates critical from non-critical traffic using a heterogeneous architecture. Such separation likely leads to performance inefficiencies or limitations in functionality. In this paper we improve a filter architecture by hardware supported temporal and spatial isolation. We show that this approach provides near optimum performance even when applied to a commercial Ethernet interface. Hardware support simplifies the stack architecture, guaranteeing high predictability for critical traffic.