ProRace: Practical data race detection for production use

This paper presents PRORACE, a dynamic data race detector practical for production runs. It is lightweight, but still offers high race detection capability. To track memory accesses, PRORACE leverages instruction sampling using the performance monitoring unit (PMU) in commodity processors. Our PMU driver enables PRORACE to sample more memory accesses at a lower cost compared to the state-of-the-art Linux driver. Moreover, PRORACE uses PMU-provided execution contexts including register states and program path, and reconstructs unsampled memory accesses offline. This technique allows PRORACE to overcome inherent limitations of sampling and improve the detection coverage by performing data race detection on the trace with not only sampled but also reconstructed memory accesses. Experiments using racy production software including apache and mysql shows that, with a reasonable offline cost, PRORACE incurs only 2.6% overhead at runtime with 27.5% detection probability with a sampling period of 10,000.