MSMPI Buffer size issue ( Message truncated )


While executing my application using 2 processes (mpiexec -np 2 ****.exe), I am getting the following error:

[0] fatal error

Fatal error in MPI_Reduce: Message truncated, error stack:

MPI_Reduce(804)…: MPI_Reduce(sbuf=0x0000000141121C00,
rbuf=0x000000000012F978, count=1, MPI_DOUBLE_PRECISION, MPI_MAX, root=0, MPI_COMM_WORLD) failed



MPIDI_CH3U_Request_unpack_uebuf(599): Message truncated; 64 bytes received but buffer size is 8

It works fine with just 1 process. I am using PGI compilers to compile the code (in cygwin environment on Windows platform) and adding the MSMPI library through the -Mmpi=msmpi flag.

I suppose the msmpi.dll being used is version 2.0.1551.0 and the OS is Windows Server 2008, HPC Edition Service Pack 2

Kindly let me know if you have any suggestions to resolve this.

Thanks & Regards,

Hi Kunal,

The PGI debugger, pgdbg, supports MPI debugging, including MSMPI, and should be able to help you identify the issue. Please see Chapter 6 of the PGI Tool’s guide, for details.

  • Mat