OpenMP job example

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In this exercise user should obtain prepared openmp job, extract archive, list content of files, submit job on PARADOX cluster, monitor his progress with information from queue and when job is done list resaults file.

1. Login on

$ ssh

2. Navigate to your folder in nfs filesystem.

$ cd /nfs/ngrkic

3. Download tgz archive with example files.


4. Extract archive :

$ tar xvzf openmp.tgz

5. Enter openmp folder

$ cd openmp

6. List content of folder:

$ ll

7. List content of job.pbs and job.c files:

$ cat job.pbs
#PBS -q hpsee
#PBS -l nodes=1:ppn=6
#PBS -l walltime=10:00:00
#PBS -e ${PBS_JOBID}.err
#PBS -o ${PBS_JOBID}.out

chmod +x job
$ cat job.c
#include <omp.h>
#include <stdio.h>
#include <stdlib.h>

int main (int argc, char *argv[]) 
int nthreads, tid;

/* Fork a team of threads giving them their own copies of variables */
#pragma omp parallel private(nthreads, tid)

  /* Obtain thread number */
  tid = omp_get_thread_num();
  printf("Hello World from thread = %d\n", tid);

  /* Only master thread does this */
  if (tid == 0) 
    nthreads = omp_get_num_threads();
    printf("Number of threads = %d\n", nthreads);

  }  /* All threads join master thread and disband */


8. Submit job :

qsub job.pbs

qsub will print output :


9. Monitor your job :

qstat <jobID>

10.When job is done list content of <jobID> file :

cat <jobID>
Hello World from thread = 0
Number of threads = 6
Hello World from thread = 1
Hello World from thread = 3
Hello World from thread = 2
Hello World from thread = 4
Hello World from thread = 5
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