WARNING: It appears that your OpenFabrics subsystem is configured to only allow registering part of your physical memory. This can cause MPI jobs to run with erratic performance, hang, and/or crash. This may be caused by your OpenFabrics vendor limiting the amount of physical memory that can be registered. You should investigate the relevant Linux kernel module parameters that control how much physical memory can be registered, and increase them to allow registering all physical memory on your machine. See this Open MPI FAQ item for more information on these Linux kernel module parameters: http://www.open-mpi.org/faq/?category=openfabrics#ib-locked-pages Local host: node02 Registerable memory: 32768 MiB Total memory: 65476 MiB Your MPI job will continue, but may be behave poorly and/or hang.The explanation solution can be found at How to increase MTT Size in Mellanox HCA.
In summary, the error occurred when applications which consumed a large amount of memory, application might fail when not enough memory can be registered with RDMA. There is a need to increase MTT size. But increasing MTT size hasve the downside of increasing the number of "cache misses" and increases latency.
For a more details writeup. See Registering sufficent memory for OpenIB when using Mellanox HCA (linuxcluster.wordpress.com)