I am trying to submit a job using salloc, i.e., 64 MPI process and each process has 4 openmp threads:

salloc --nodes=8 --ntasks-per-node=8 --cpus-per-task=4 --exclusive mpirun --mca mtl psm --bind-to none ./test 

I always got the error :

salloc: error: CPU count per node can not be satisfied

Is there any way to decide how many nodes are needed and how many mpi process can run at each node, and how many openmp threads can run on each mpi process?