Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision		 Previous revision
doku:multimpi [2021/04/01 07:03] – markusdoku:multimpi [2023/03/14 12:53] (current) – [VSC-3] goldenberg
Line 5: Line 5:
 ==== VSC-4 ===== ==== VSC-4 =====
  
-Sample Job when for running multiple mpi jobs on a VSC-4 node. Note:+Sample Job when for running multiple mpi jobs on a VSC-4 node.  
 + 
 +Note: The "mem_per_task" should be set such that
  
 <code> <code>
-#!/bin/bash +mem_per_task * mytasks < mem_per_node - 2Gb
-#SBATCH -J many +
-#SBATCH -N 1 +
- +
-export SLURM_STEP_GRES=none +
- +
-mytasks=4 +
-cmd="stress -c 24" +
-mem_per_task=10G +
- +
-for i in `seq 1 $mytasks` +
-do +
-        srun --mem=$mem_per_task --cpus-per-task=2 --ntasks=1 $cmd & +
-done +
-wait +
 </code> </code>
  
-==== VSC-3 =====+The approx 2Gb reduction in available memory is due to operating system stored in memory. For a standard node with 96 Gb of Memory this would be eg.:
  
-=== With srun: === 
 <code> <code>
-#!/bin/bash +23 Gb * 4 = 92 Gb < 94 Gb
-#SBATCH -J test +
-#SBATCH -N 1 +
-#SBATCH --ntasks-per-core=1 +
-#SBATCH --ntasks-per-node=2 +
- +
-export SLURM_STEP_GRES=none +
- +
-module load intel/18 intel-mpi/2018 +
- +
-for i in 0 8 +
-do +
-  j=$(($i+1)) +
-  srun -n 2 --cpu_bind=map_cpu:$i,$j ./hello_world_intelmpi2018 & +
-done +
-wait +
- +
-exit 0+
 </code> </code>
- 
-=== With mpirun (Intel MPI): === 
  
 <code> <code>
 #!/bin/bash #!/bin/bash
-#SBATCH -J test+#SBATCH -J many
 #SBATCH -N 1 #SBATCH -N 1
-#SBATCH --ntasks-per-core=1 
-#SBATCH --ntasks-per-node=2 
  
 export SLURM_STEP_GRES=none export SLURM_STEP_GRES=none
  
-module load intel/18 intel-mpi/2018+mytasks=4 
 +cmd="stress -c 24" 
 +mem_per_task=10G
  
-for i in 0 8+for i in `seq 1 $mytasks`
 do do
-  j=$(($i+1)) +        srun --mem=$mem_per_task --cpus-per-task=2 --ntasks=1 $cmd &
-  mpirun -env I_MPI_PIN_PROCESSOR_LIST $i,$j -np 2 ./hello_world_intelmpi2018 &+
 done done
 wait wait
  
-exit 0 
-</code> 
- 
-You can download the C code example here: {{ :doku:hello_world.c |hello_world.c}} 
- 
-Compile it e.g. with: 
- 
-<code> 
-# module load intel/18 intel-mpi/2018 
-# mpiicc -lhwloc hello_world.c -o hello_world_intelmpi2018 
 </code> </code>
  
  
  • doku/multimpi.1617260607.txt.gz
  • Last modified: 2021/04/01 07:03
  • by markus