Program partitioning and deadlock analysis for MPI based on logical clocks

Abstract

The message passing interface (MPI) has become a standard for programming models in the field of high performance computing. It is of great importance to ensure the reliability of MPI programs by detecting whether there exist errors in them. However, as one of the most common errors in MPI programs, deadlock is difficult to detect due to the non-determinism and the asynchronous communication supported by MPI. Existing approaches mainly focus on detecting deadlocks by traversing all possible execution paths in an MPI program. But in this way the detection efficiency is always limited since the number of execution paths increases exponentially with the number of wildcard receives and processes in the program.

In order to alleviate the path explosion problem for single-path MPI programs, we propose a program partitioning approach based on logical clocks to detecting deadlocks. In the approach, the program is first divided into several preliminary partitions based on the matching detection rule. Then to obtain the dependency relationships of partitions, the Binary Lazy Clocks algorithm is raised to mark clocks for communication operations. Based on the clocks, the completion orders of communication operations in each process of the program are tracked. Further, we get the dependency relationships of the preliminary partitions by analyzing these completion orders and merge the preliminary partitions with the dependency relationships for generating the final partitions. Finally, deadlocks are detected by traversing all possible execution paths of each final partition. We have implemented our method in a tool called PDMPI and performed experimental evaluation on 14 programs. The experimental results indicate that PDMPI is more effective for detecting deadlocks in MPI programs than two most related tools ISP and SAMPI, especially in programs with numerous interleavings.