Dynamic Detection and Mitigation of DMA Races in MPSoCs

Explicitly managed memories have emerged as a good alternative for multicore processors design in order to reduce energy and performance costs. Memory transfers then rely on Direct Memory Access (DMA) engines which provide a hardware support for accelerating data. However, programming explicit data transfers is very challenging for developers who must manually orchestrate data movements through the memory hierarchy. This is in practice very error-prone and can easily lead to memory inconsistency. In this paper, we propose a runtime approach for monitoring DMA races. The monitor acts as a safeguard for programmers and is able to enforce at runtime a correct behavior w.r.t the semantics of the program execution. We validate the approach using traces extracted from industrial benchmarks and executed on the multiprocessor system-onchip platform STHORM. Our experiments demonstrate that the monitoring algorithm has a low overhead (less than 1.5 KB) of on-chip memory consumption and an overhead of less than 2% of additional execution time.