Optimized process placement for collective I/O operations

Mapping of MPI processes to the available resources is an increasingly complex but important task on modern parallel systems. This paper presents a new approach to optimize the process placement of a parallel application based on its I/O access pattern. The paper introduces the SetMatch process mapping algorithm, which significantly reduces the cost of the communication occurring in collective I/O operations. The effectiveness of the approach has been evaluated for multiple scenarios on a PVFS2 file system. Our results demonstrate significant improvements in the communication time of collective I/O operations as well as improvements in the overall application execution time with our mapping strategy. The generalized SetMatch algorithm was the only mapping strategy that was able to provide adequate performance for all scenarios used in this paper.