FluidCheck: A Redundant Threading-Based Approach for Reliable Execution in Manycore Processors

Soft errors have become a serious cause of concern with reducing feature sizes. The ability to accommodate complex, Simultaneous Multithreading (SMT) cores on a single chip presents a unique opportunity to achieve reliable execution, safe from soft errors, with low performance penalties. In this context, we present FluidCheck, a checker architecture that allows highly flexible assignment and migration of checking duties across cores. In this article, we present a mechanism to dynamically use the resources of SMT cores for checking the results of other threads, and propose a variety of heuristics for migration of such checker threads across cores. Secondly, to make the process of checking more efficient, we propose a set of architectural enhancements that reduce power consumption, decrease the length of the critical path, and reduce the load on the Network-on-Chip (NoC). Based on our observations, we design a 16 core system for running SPEC2006 based bag-of-tasks applications. Our experiments demonstrate that fully reliable execution can be attained with a mere 27p slowdown, surpassing traditional redundant threading based techniques by roughly 42p.