I am running IMB (Intel MPI Benchmarks), the MPI-1 benchmarks, which was built with Intel 12.1 compiler suite and OpenMPI 1.6.5 (and running w/ OMPI 1.6.5). I decided to use the following for the mca parameters:
--mca btl openib,tcp,self --mca btl_openib_receive_queues X,9216,256,128,32:X,65536,256,128,32
where before, I always used "--mca btl openib,tcp,self". This is for performance analysis. On the SendRecv benchmark at 32 processes, IMB hangs. I then tried:
--mca btl_openib_receive_queues X,128,256,192,128:X,2048,256,128,32:X,12288,256,128,32:X,65536,256,128,32
and IMB also hangs on the SendRecv benchmark, though at 64 processes.
No errors have been recorded, not even in any system log files but 'top' shows the MPI tasks running. How can I go about troubleshooting this hang, as well as figuring out what (If any) MCA XRC-related parameters in btl_openib_receive_queues I have to specify to get IMB running properly? I did verify the IB cards are ConnectX.