Fault-aware task re-mapping for throughput constrained multimedia applications on NoC-based MPSoCs

Abstract

Shrinking transistor geometry and aggressive voltage scaling are leading to growing concerns on the reliability of multiprocessor systems. Majority of streaming multimedia applications are characterized by fixed throughput requirements; violation of which directly impacts user experience. None of the prior research considers joint treatment of throughput and task-migration overhead, both of which are essential for fault-tolerance of throughput-constrained multimedia multiprocessor systems. In this paper, we propose to remap tasks from faulty processors with the objective of minimizing the migration overhead while satisfying throughput constraints. The proposed technique is based on extensive design-time analysis of different fault scenarios to determine optimal mappings from the throughput-migration overhead Pareto space. These mappings are stored in a table and are looked-up at run-time to migrate tasks as and when faults occur. Applications are modeled using Synchronous Data Flow graphs (SDFG) to consider cyclic dependencies of tasks, typically found in multimedia systems. Experiments performed with synthetic and real application graphs demonstrate that the migration overhead can be reduced by 26% on average while still meeting throughput constraints. Moreover, by selecting an appropriate initial processor-task mapping, migration overhead can be further reduced by 15% on average.