I recently noticed the following warning in OpenMC version 0.15.0 (Conda installation):
[ubuntu:13425] shmem: mmap: an error occurred while determining whether or not /tmp/ompi.ubuntu.1000/jf.0/2604400640/shared_mem_cuda_pool.ubuntu could be created.
[ubuntu:13425] create_and_attach: unable to create shared memory BTL coordinating structure :: size 134217728
I manually increased the shared memory by running:
sudo sysctl -w kernel.shmmax=34359738368
sudo sysctl -w kernel.shmall=8388608
But the warning persisted. I tried running OpenMC using:
mpirun --mca btl_smcuda_use_cuda 0 -np 8 openmc
This suppresses the warning. However, I wanted to add that setting permanently to OpenMPI parameters, so I added
btl_smcuda_use_cuda = 0
to:
~/miniconda3/envs/openmc-env/etc/openmpi-mca-params.conf
It did not work. I removed the Conda environment and reinstalled OpenMC v0.15.0, but the warning is still there. The warning has not caused any issues with functionality so far.
I also reinstalled OpenMC v0.14.0 in a different Conda environment to check if the same warning appears, but it does not.
I was wondering if anyone else has encountered this warning.
Thank you.