MC-CChecker
Thanh-Dang Diep, Karl Fürlinger, Nam Thoai · 2018
MPI one-sided communication decouples data movement from synchronization, which eliminates overhead from unneeded synchronization and allows for greater concurrency. On the one hand this fact is the great advantage of MPI one-sided communication, but on the other, it poses enormous challenges for programmers in preserving the reliability of programs. Memory consistency errors are notorious for degrading reliability as well as performance of MPI one-sided applications. Even an MPI expert can easily make these mistakes. The lockopts bug occurred in an RMA test case that is part of MPICH MPI implementation is an example for this situation. Hence, detecting memory consistency errors is extremely challenging. MC-Checker is the most cutting-edge debugger to address these errors effectively. MC-Checker tackles the memory consistency errors based on the happened-before relation. Taking full advantage of the relation makes DN-Analyzer of MC-Checker difficult to scale well. For that reason, MC-Checker does ignore the transitive ordering of the happened-before relation to retain scalability of DN-Analyzer. Consequently, MC-Checker is highly able to impose a potential source of false positives.