Preparation

2. Use your username to connect to MeluXina¶

2.1 For example the below example shows the user of u100490

$ ssh u100490@login.lxp.lu -p 8822
### or
$ ssh meluxina

3. Once you have logged in¶

3.1 Once you have logged in, you will be in a default home directory
```
[u100490@login02 ~]$ pwd
/home/users/u100490
```

3.2 After that, go to the project directory.

[u100490@login02 ~]$ cd /project/home/p200117
[u100490@login02 p200117]$ pwd
/project/home/p200117

4. And please create your own working folder under the project directory¶

4.1 For example, here is the user with u100490:

[u100490@login02 p200117]$ mkdir $USER
### or 
[u100490@login02 p200117]$ mkdir u100490

5. Now it is time to move into your home directory¶

5.1 For example, with user home directory u100490
```
[u100490@login02 p200117]$cd u100490
```

6. Now it is time to copy the folder which has examples and source files to your home directory¶

6.1 For example, with user home directory u100490

[u100490@login03 u100490]$ cp -r /project/home/p200117/OpenMP .
[u100490@login03 u100490]$ cd OpenMP/
[u100490@login03 OpenMP]$ pwd
/project/home/p200117/u100490/OpenMP
[u100490@login03 OpenMP]$ ls -lthr
drwxr-s---. 2 u100490 p200117 4.0K May 27 21:42 Data-Sharing-Attribute
drwxr-s---. 2 u100490 p200117 4.0K May 28 00:35 Parallel-Region
drwxr-s---. 2 u100490 p200117 4.0K May 30 18:26 Dry-run-test
...
...

7.1 Reserve the interactive node for running/testing OpenMP applications

$ salloc -A p200117 --res intro_openmp --partition=cpu --qos default -N 1 -t 01:00:00

check if your reservation is allocated

[u100490@login03 ~]$ salloc -A p200117 --res intro_openmp --partition=cpu --qos default -N 1 -t 01:00:00
salloc: Pending job allocation 296848
salloc: job 296848 queued and waiting for resources
salloc: job 296848 has been allocated resources
salloc: Granted job allocation 296848
salloc: Waiting for resource configuration
salloc: Nodes mel2131 are ready for job

7.2 You can also check if you got the interactive node for your computations, for example, here with the user u100490:

[u100490@mel2131 ~]$ squeue -u u100490
            JOBID PARTITION     NAME     USER    ACCOUNT    STATE       TIME   TIME_LIMIT  NODES NODELIST(REASON)
           304381       cpu interact  u100490    p200117  RUNNING       0:37     01:00:00      1 mel2131

8. Now we need to check simple OpenMP application, if that is going to work for you:¶

8.1 Go to folder Dry-run-test

[u100490@login03 OpenMP]$ cd Dry-run-test/
[u100490@login03 Dry-run-test]$ ls 
source.sh  Test.cc  Test.f90

9. Finally, we need to load the compiler to test the our OpenMP codes¶

9.1 We will work with GNU compiler

$ source module.sh

check if the module is loaded properly

[u100490@mel2131 ~]$ module list

currently Loaded Modules:
1) env/release/2022.1                (S)  19) libpciaccess/0.16-GCCcore-11.3.0    37) jbigkit/2.1-GCCcore-11.3.0        55) VTune/2022.3.0                          73) NSS/3.79-GCCcore-11.3.0
2) lxp-tools/myquota/0.3.1           (S)  20) X11/20220504-GCCcore-11.3.0         38) gzip/1.12-GCCcore-11.3.0          56) numactl/2.0.14-GCCcore-11.3.0           74) snappy/1.1.9-GCCcore-11.3.0
3) GCCcore/11.3.0                         21) Arm-Forge/22.0.4-GCC-11.3.0         39) lz4/1.9.3-GCCcore-11.3.0          57) hwloc/2.7.1-GCCcore-11.3.0              75) JasPer/2.0.33-GCCcore-11.3.0
4) zlib/1.2.12-GCCcore-11.3.0             22) libglvnd/1.4.0-GCCcore-11.3.0       40) zstd/1.5.2-GCCcore-11.3.0         58) OpenSSL/1.1                             76) nodejs/16.15.1-GCCcore-11.3.0
5) binutils/2.38-GCCcore-11.3.0           23) AMD-uProf/3.6.449                   41) libdeflate/1.10-GCCcore-11.3.0    59) libevent/2.1.12-GCCcore-11.3.0          77) Qt5/5.15.5-GCCcore-11.3.0
6) ncurses/6.3-GCCcore-11.3.0             24) Advisor/2022.1.0                    42) LibTIFF/4.3.0-GCCcore-11.3.0      60) UCX/1.13.1-GCCcore-11.3.0               78) CubeGUI/4.7-GCCcore-11.3.0
Where:
    S:  Module is Sticky, requires --force to unload or purge

10. Please compile and test your OpenMP application¶

10.1 For example, Dry-run-test

// compilation (C/C++)
$ g++ Test.cc -fopenmp

// compilation (FORTRAN)
$ gfortran Test.f90 -fopenmp

// execution
$ ./a.out

// output
$ Hello world from master thread 
  Hello world from thread id Hello world from thread id Hello world from thread 
  id Hello world from thread id Hello world from thread id 4 from the team size of 
  1 from the team size of 20 from the team size of  from the team size of 555

11. Similarly for the hands-on session, we need to do the node reservation:¶

11.1 For example, reservation

$ salloc -A p200117 --res intro_openmp --partition=cpu --qos default -N 1 -t 02:30:00