Thank you! I’ll see if this is an option … would be nice. I’ll see if we can try this.
Best wishes Volker > On Feb 25, 2021, at 11:07 PM, Angelos Ching <angelosch...@clustertech.com> > wrote: > > I think it's related to the job step launch semantic change introduced at > 20.11.0, which has been reverted since 20.11.3, see > https://www.schedmd.com/news.php For details. > > Cheers, > Angelos > (Sent from mobile, please pardon me for typos and cursoriness.) > >> 26/2/2021 9:07、Volker Blum <volker.b...@duke.edu>のメール: >> >> Hi, >> >> I am testing slurm 20.11.2 on a local cluster together with Intel MPI >> 2018.4.274 . >> >> >> 1) On a single node (20 physical cores) and executed manually (no slurm), a >> particular application runs fine using Intel’s mpirun, execution time for >> this example: 8.505 s (wall clock). >> >> (this is a straight MPI application, no complications) >> >> >> 2) Using slurm and Intel’s mpirun through a queue / batch script, >> >> #SBATCH --ntasks-per-node=20 >> >> >> … >> mpirun -n 20 $bin > file.out >> >> the same job runs correcty but takes 121.735 s (wall clock!) >> >> >> 3) After some considerable searching, a partial fix is >> >> #SBATCH --ntasks-per-node=20 >> >> >> ... >> export I_MPI_PMI_LIBRARY=/usr/lib64/libpmi.so.0 >> srun --cpu-bind=cores -n 20 $bin > file.out >> >> can bring down the execution time to 13.482 s >> >> >> 4) After changing >> >> #SBATCH --ntasks-per-node=20 >> >> >> #SBATCH --cpus-per-task=2 >> >> >> ... >> export I_MPI_PMI_LIBRARY=/usr/lib64/libpmi.so.0 >> srun --cpu-bind=cores -n 20 $bin > file.out >> >> finally, the time is: 8.480 s >> >> This timing is as it should be, but at the price of pretending that an >> application is multithreaded when it is, in fact, not multithreaded. >> >> *** >> >> Is it possible to just keep Intel MPI defaults intact when using its mpirun >> in a slurm batch script? >> >> Best wishes >> Volker >> >> Volker Blum >> Associate Professor >> Ab Initio Materials Simulations >> Thomas Lord Department of Mechanical Engineering and Materials Science >> Duke University >> https://aims.pratt.duke.edu >> >> volker.b...@duke.edu >> Twitter: Aimsduke >> >> Office: 4308 Chesterfield Building >> >> >> >> >> >> >> >> >> Volker Blum Associate Professor Ab Initio Materials Simulations Thomas Lord Department of Mechanical Engineering and Materials Science Duke University https://aims.pratt.duke.edu volker.b...@duke.edu Twitter: Aimsduke Office: 4308 Chesterfield Building
