OpenMP

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Revision as of 16:09, 11 February 2013 by Shtsai (talk | contribs)
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Compiling OpenMP code on zcluster

The compilers installed on zcluster support shared memory applications using OpenMP. Here are the compiler options to include when using OpenMP:

Compiler Commands Option
PGI pgcc, pgCC, pgf90, etc. -mp
Intel icc, ifort -openmp
GNU gcc, gfortran, g++, gcc44, etc. -fopenmp

Defining number of OpenMP threads

The number of OpenMP threads can be specified using the environment variable OMP_NUM_THREADS. For example, to define 4 threads:

For bash/sh:

export OMP_NUM_THREADS=4

For csh/tcsh:

setenv OMP_NUM_THREADS 4

Sample script to run a shared memory job using OpenMP

Sample script to run a program that uses 4 OpenMP threads:

#!/bin/bash
cd working_directory
export OMP_NUM_THREADS=4
time ./myprog