Enhancing the performance of malleable MPI applications by using performance-aware dynamic reconfiguration

• We present Flex-MPI, an MPI extension which supports malleability for MPI programs.
• We introduce a performance-aware dynamic reconfiguring technique for malleability.
• We implement a prediction model to estimate the performance of MPI programs.
• We present a simple API to access Flex-MPI functionalities from MPI applications.
• We demonstrate Flex-MPI capabilities to enhance performance via malleability.

The work in this paper focuses on providing malleability to MPI applications by using a novel performance-aware dynamic reconfiguration technique. This paper describes the design and implementation of Flex-MPI, an MPI library extension which can automatically monitor and predict the performance of applications, balance and redistribute the workload, and reconfigure the application at runtime by changing the number of processes. Unlike existent approaches, our reconfiguring policy is guided by user-defined performance criteria. We focus on iterative SPMD programs, a class of applications with critical mass within the scientific community. Extensive experiments show that Flex-MPI can improve the performance, parallel efficiency, and cost-efficiency of MPI programs with a minimal effort from the programmer.