CINECA slurm update to 22.05.8 version – IMPORTANT NOTE for hybrid runs

Dear Users,
as announced at the end of Marconi maintenance on February 14, we updated the slurm scheduler to version 22.05.8; please, find the release notes at the link
https://slurm.schedmd.com/news.html
Please note a major modification, reported in the Highlights of the release notes:
srun will no longer read in SLURM_CPUS_PER_TASK. This means you will explicitly have to specify –cpus-per-task on your srun calls, or set the new SRUN_CPUS_PER_TASK env var to accomplish the same thing.Such modification affects hybrid (MPI/OpenMP) jobs launched with srun, since the consequent mapping of the multithreaded tasks will result in an overallocation of the cpus. As reported in the slurm Highlights, you can

define the SRUN_CPUS_PER_TASK env var in your scripts:

export SRUN_CPUS_PER_TASK=$SLURM_CPUS_PER_TASKsrun your_exe
or your can repeat the –cpus-per-task directive as option of srun:

srun –cpus-per-task=$SLURM_CPUS_PER_TASK your_exeBest regards,
HPC User Support @ CINECA