[Haowang]

Hello everyone,
I'll read a paper http://web.stanford.edu/~economon/do...-2015-1949.pdf about maximizing parallelism. I noticed that SU2-5.0 surpports hybridization to MPI+OpenMP. The author found that for a specified case the best performance is obtained for 6 MPI ranks (with 8 OMP threads attached to each rank).

But i don't know how to set the hybridization settings, for example, excuting SU2_CFD in 6 MPI ranks (with 8 OMP threads attached to each rank). The command for parallelization of SU2 is "mpirun -n 6 SU2_CFD config.cfg" or "parallel_computation.py -n 6 -f config.cfg" ,and there is nothing to do with the hybridization settings, or it is automatic internal SU2 ? Could anyone help me with this? Thank you very much!
By the way, I have made some attempts on a cluster (the job-submittal environment is slurm):
#!/bin/bash
export OMP_NUM_THREADS=6
yhrun -N 1 -n 2 -c 6 -p debug SU2_CFD opt_crm.cfg
where 'N' is the number of nodes （there are 12 physical cores）, 'n' is the number of ranks, 'c' is the number of threads. But it seems that SU2_CFD runs on only 2 cores.
I also tried:
#!/bin/bash
export OMP_NUM_THREADS=6
yhrun -n 2 -c 6 -p debug finite_differences.py -n 12 -f opt_crm.cfg
then SU2 returns this message "srun: error: Unable to create job step: More processors requested than permitted"

ps: When i built the code with:
./configure --prefix=/vol6/home/zhhan/wh/SU-5TEST CXXFLAGS="-O3" --enable-mpi
make -j 12
It returns many warnings like:
"Gklib/csr.c(1574):warning #161: unrecognized #pragma #pragma omp parallel if (rowptr[nrows] >OMPMINOPS)"

[talbring]

Hi Haowang,

SU2 currently does not support hybrid parallelization using MPI+OpenMP. The modifications regarding this in the linked paper were done in a special version of the code.

Tim

[Haowang]

Originally Posted by talbring

Hi Haowang,

SU2 currently does not support hybrid parallelization using MPI+OpenMP. The modifications regarding this in the linked paper were done in a special version of the code.

Tim

Thanks Tim, it helps a lot!