GA

Overview

Global Arrays (GA) is a Partitioned Global Address Space (PGAS) programming model. It provides primitives for one-sided communication (Get, Put, Accumulate) and Atomic Operations (read increment). It supports blocking and non-blocking primtives, and supports location consistency.

More information is available on the GA web site: https://hpc.pnl.gov/globalarrays/

It is used on Gadi to build OpenMolcas and NWChem.

GA starting with v5.7.2 is build with different MPI flavors and with Intel and GNU compilers. Separate MPI based options (mpi-mt, mpi-pr, mpi-ts, mpi3, ofa, openib).

Usage

The directory structure is 3 layer, so you need to specify the library path exactly, for example:

# Load module, always specify version number.
$ module load ga/5.7.2

$ EXTERNAL_GA_PATH=$GA_BASE/mpi-ts/ompi3/Intel