Supporting Task Migration in Multi-Processor Systems-on-Chip: a Feasibility Study

With the advent of multi-processor systems-on-chip, the interest in process migration is again on the rise both in research and in product development. New challenges associated with the new scenario include increased sensitivity to implementation complexity, tight power budgets, requirements on execution predictability, the lack of virtual memory support in many low-end MPSoCs. As a consequence, effectiveness and applicability of traditional transparent migration mechanisms are put in discussion in this context. Our paper proposes a task management software infrastructure that is well suited for the constraints of single chip multiprocessors with distributed operating systems. Load balancing in the system is maintained by means of intelligent initial placement and task migration. We propose a user-managed migration scheme based on code checkpointing and user-level middleware support as an effective solution for many MPSoC application domains. In order to prove the practical viability of this scheme, we also propose a characterization methodology for task migration overhead. We derive the minimum execution time following a task migration event during which the system configuration should be frozen to make up for the migration cost