An OpenMP-only Linear Algebra Library for Distributed Architectures

This paper presents a dense linear algebra library for distributed memory systems called OMPC PLASMA. It leverages the OpenMP Cluster (OMPC) programming model to enable the execution of the PLASMA library using task parallelism on a distributed cluster architecture. OpenMP Cluster model is used to define the task regions that are then distribute across the cluster nodes by the OMPC runtime that automatically manages task scheduling, communications between nodes, and fault tolerance. The OMPC PLASMA library modifies various PLASMA functions to distribute the matrix across the nodes and perform the calculation using threads of the node. Experimental results show that OMPC PLASMA achieves 4.00x with 4 worker nodes, 7.00x with 8 worker nodes, and 12.00x with 16 worker nodes acceleration over its original implementation for a single node. A 3.00x speedup is achieved when comparing OMPC PLASMA execution to ScaLAPACK, for 4 worker nodes, and a matrix size of 90k×90k.