Efficient and truly passive MPI-3 RMA using InfiniBand atomics
Mengzhu Li, Sreeram Potluri, Khaled Hamidouche, Jithin Jose, Dhabaleswar K. DK Panda · 2013
Multi/many-core architectures offer high compute density on modern supercomputing clusters. It is critical for applications to minimize communication and synchronization overheads to achieve peak performance. MPI offers one-sided communication semantics that are aimed at enabling this. In this paper, we propose a novel design for implementing truly passive shared and exclusive MPI_Win_lock/unlock using InfiniBand atomics. We address limitations in designs published earlier. We also present the impact of our design on MPI_Win_lock all introduced in MPI-3. We demonstrate superior overlap compared to existing two-sided implementations. Using Splash LU kernel, proposed design delivers upto 49% performance improvement compared to existing designs.