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/p200301
[u100490@login02 p200301]$ pwd
/project/home/p200301

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

4.1 For example, here is the user with u100490:

[u100490@login02 p200301]$ mkdir $USER
### or 
[u100490@login02 p200301]$ mkdir u100490

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

5.1 For example, with user home directory u100490
```
[u100490@login02 p200301]$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/p200301/OpenMP .
[u100490@login03 u100490]$ cd OpenMP/
[u100490@login03 OpenMP]$ pwd
/project/home/p200301/u100490/OpenMP
[u100490@login03 OpenMP]$ ls -lthr
drwxr-s---. 2 u100490 p200301 4.0K May 27 21:42 Data-Sharing-Attribute
drwxr-s---. 2 u100490 p200301 4.0K May 28 00:35 Parallel-Region
drwxr-s---. 2 u100490 p200301 4.0K May 30 18:26 Dry-run-test
...
...

7.1 Reserve the interactive node for running/testing OpenMP applications

$ salloc -A p200301 --res eurocc2-cpu-course-morning --partition=cpu --qos default -N 1 -t 01:00:00

check if your reservation is allocated

[u100490@login03 ~]$ salloc -A p200301 --res eurocc2-cpu-course-morning --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    p200301  RUNNING       0:37     01:00:00      1 mel2131

8. Now we need to check a 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 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 the 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 p200301 --res eurocc2-cpu-course-afternoon --partition=cpu --qos default -N 1 -t 02:30:00