CAROL-FI: An efficient fault-injection tool for vulnerability evaluation of modern HPC parallel accelerators

Transient faults are a major problem for large scale HPC systems, and the mitigation of adverse fault effects need to be highly efficient as we approach exascale. We developed a fault injection tool (CAROL-FI) to identify the potential sources of adverse fault effects. With a deeper understanding of such effects, we provide useful insights to design efficient mitigation techniques, like selective hardening of critical portions of the code. We performed a fault injection campaign injecting more than 67, 000 faults into an Intel Xeon Phi executing six repre-sentative HPC programs. We show that selective hardening can be successfully applied to DGEMM and Hotspot while LavaMD and NW may require a complete code hardening.