High performance MPI library over SR-IOV enabled infiniband clusters

Virtualization has become a central role in HPC Cloud due to easy management and low cost of computation and communication. Recently, Single Root I/O Virtualization (SR-IOV) technology has been introduced for high-performance interconnects such as InfiniBand and can attain near to native performance for inter-node communication. However, the SR-IOV scheme lacks locality aware communication support, which leads to performance overheads for inter-VM communication within a same physical node. To address this issue, this paper first proposes a high performance design of MPI library over SR-IOV enabled InfiniBand clusters by dynamically detecting VM locality and coordinating data movements between SR-IOV and Inter-VM shared memory (IVShmem) channels. Through our proposed design, MPI applications running in virtualized mode can achieve efficient locality-aware communication on SR-IOV enabled InfiniBand clusters. In addition, we optimize communications in IVShmem and SR-IOV channels by analyzing the performance impact of core mechanisms and parameters inside MPI library to deliver better performance in virtual machines. Finally, we conduct comprehensive performance studies by using point-to-point and collective benchmarks, and HPC applications. Experimental evaluations show that our proposed MPI library design can significantly improve the performance for point-to-point and collective operations, and MPI applications with different InfiniBand transport protocols (RC and UD) by up to 158%, 76%, 43%, respectively, compared with SR-IOV. To the best of our knowledge, this is the first study to offer a high performance MPI library that supports efficient locality aware MPI communication over SR-IOV enabled InfiniBand clusters.