Multicore in Real-Time Systems – Temporal Isolation Challenges due to Shared Resources

Abstract

Recent advent of multicore platforms, along withassociated desire for porting of aerospace applications to suchplatforms, pose a significant challenge for real-time execution.Sharing the on-chip resources introduces lowlevel temporaleffects that impact the execution time determinism by a multitudeof mechanisms. We discuss such mechanisms in this paperand we outline possible approaches to mitigate them or boundtheir temporal impact. We assume a mixed-criticality real-timeenvironment, as is typical in aerospace applications; it is howeveralso applicable to similar use cases in automotive and industrialcontrol. © CISTER Research Center www.cister.isep.ipp.pt 1 Multicore In Real-Time Systems – Temporal Isolation Challenges Due To Shared Resources Ondřej Kotaba∗, Jan Nowotsch†, Michael Paulitsch†, Stefan M. Petters‡ and Henrik Theiling§ ∗Honeywell International, s.r.o., Aerospace Advanced Technologies, Czech Republic, [e-mail] †EADS Innovation Works, Germany, [jan.nowotsch,michael.paulitsch]@eads.net ‡ISEP, Polytechnic Institute of Porto, Portugal, [e-mail] §SYSGO AG, Germany, [e-mail] Abstract— Recent advent of multicore platforms, along with associated desire for porting of aerospace applications to such platforms, pose a significant challenge for real-time execution. Sharing the on-chip resources introduces low-level temporal effects that impact the execution time determinism by a multitude of mechanisms. We discuss such mechanisms in this paper and we outline possible approaches to mitigate them or bound their temporal impact. We assume a mixed-criticality real-time environment, as is typical in aerospace applications; it is however also applicable to similar use cases in automotive and industrial control. Recent advent of multicore platforms, along with associated desire for porting of aerospace applications to such platforms, pose a significant challenge for real-time execution. Sharing the on-chip resources introduces low-level temporal effects that impact the execution time determinism by a multitude of mechanisms. We discuss such mechanisms in this paper and we outline possible approaches to mitigate them or bound their temporal impact. We assume a mixed-criticality real-time environment, as is typical in aerospace applications; it is however also applicable to similar use cases in automotive and industrial control.