Response time in mixed-critical pervasive systems

Pervasive computing systems at large scale rely on real-time scheduling on the top of distributed and networked computing environments. From an user experience perspective, while the requirements on the response time for specific applications might be different, the mixed-criticality in real-time scheduling, which provide diverse response time guarantee for applications, is often required. In this paper, we study the real-time scheduling problem in mixed-critical pervasive computing systems. We first analyze the response time requirements for common networked pervasive computing systems, and model the mixed-criticality using the minimum response time Quality-of-Service (QoS) that should be guaranteed even in the worst-case. Then, we propose to leverage Fixed-Priority Rate-Monotonic (FPRM) Scheduler for real-time scheduling. We evaluate FPRM using synthetic workloads generated according to the real-world pervasive computing systems. Both simulation experiments and worst-case analytical results show that, when sufficient resources are given, all pervasive computing tasks can be completed subject to the response time requirements strictly with mixed-criticality guarantees ensured.