I have just found a bug in my
mpi code. On blues the
bug resulted in the following single stderr line
Fatal error in MPI_Recv: Message truncated
with no clue as to where it happened. Fortunately I had
noticed that in the latest production mpich that I installed
(with Ken's help) on my cluster I get more info. Indeed
there I got the following:
Fatal error in MPI_Recv: Message truncated, error stack:
MPI_Recv(184).......................: MPI_Recv(buf=0x4036510,
count=1, dtype=USER<contig>, src=MPI_ANY_SOURCE, tag=101,
comm=0x84000002, status=0xb3b920) failed
MPIDI_CH3U_Request_unpack_uebuf(605): Message truncated; 29292
bytes received but buffer size is 488
The tag=101 was enough in this case for me to locate the error.
But a little more info would be useful:
1) The rank of the process with the failing receive.
2) The actual rank of the sending process.
3) If at all possible, trigger a traceback and coredump of the
rank with the failing receive.
Steve
--
Steven C. Pieper: spieper@anl.gov
Argonne National Laboratory, Physics Division, Bldg. 203, Argonne, IL 60439
Phone: 630-252-4232 Fax -6008
Secretary, Debra Morrison, -4100