Dear MPI users, I am struggling against the bad behaviour of a MPI code. These are the basic informations:
a) fortran intel11 or intel 12 and OpenMPI 1.4.1 and 1.4.3 give the same problem. activating -traceback compiler option, I see the program stops at MPI_Waitany. MPI_Waitany waits for the completion of an array of MPI_IRecv: looping for the number of array components at the end all receives should be completed. The programs stops at unpredictable points (after 1 or 5 or 24 hours of computation). Sometimes I have sigsegv: mca_btl_openib.so 00002BA74D29D181 Unknown Unknown Unknown mca_btl_openib.so 00002BA74D29C6FF Unknown Unknown Unknown mca_btl_openib.so 00002BA74D29C033 Unknown Unknown Unknown libopen-pal.so.0 00002BA74835C3E6 Unknown Unknown Unknown libmpi.so.0 00002BA747E485AD Unknown Unknown Unknown libmpi.so.0 00002BA747E7857D Unknown Unknown Unknown libmpi_f77.so.0 00002BA747C047C4 Unknown Unknown Unknown cosa.mpi 00000000004F856B waitanymessages_ 1292 parallelutils.f cosa.mpi 00000000004C8044 cutman_q_ 2084 bc.f cosa.mpi 0000000000413369 smooth_ 2029 cosa.f cosa.mpi 0000000000410782 mg_ 810 cosa.f cosa.mpi 000000000040FB78 MAIN__ 537 cosa.f cosa.mpi 000000000040C1FC Unknown Unknown Unknown libc.so.6 00002BA7490AE994 Unknown Unknown Unknown cosa.mpi 000000000040C109 Unknown Unknown Unknown -------------------------------------------------------------------------- mpirun has exited due to process rank 34 with PID 10335 on node neo251 exiting without calling "finalize". This may have caused other processes in the application to be terminated by signals sent by mpirun (as reported here). -------------------------------------------------------------------------- Waitanymessages is just a wrapper of MPI_Waitany. Sometimes, the run stops writing anything on screen and I do not know what is happening (probably MPI_Waitany hangs). Before reaching segafault or hanging, results are always correct, as checked using the serial version of the code. b) The problem occurs only using openib (using TCP/IP it works) and only using more than one node on our main cluster . Trying many possibile workarounds, I found that running using: -mca btl_openib_use_eager_rdma 0 -mca btl_openib_max_eager_rdma 0 -mca btl_openib_flags 1 the problems seems not to occur. I would be very thankful to anyone which can help me to make us sure there is no bug in the code and, anyway, to discover the reason of such a "dangerous" behaviour. I can give any further information if needed, and I apologize if the post is not enough clear or complete. regards, Francesco
