[mpich-discuss] Problem with RMA && MPI_Type_vector when stride value is relatively large

Victor Vysotskiy victor.vysotskiy at teokem.lu.se
Thu Oct 16 06:34:11 CDT 2014


Hi,

I am straggling with a simple MPI program when a vector derived datatype is used as origin/remote datatypes in the MPI_Put RMA operation.  The underlying idea is quite simple: a contiguous  piece of memory is interpreted as a 2D array and only its certain slice is going to be updated via MPI_Put. To this end, I am using a  MPI_Type_vector call. Everything works fine when the stride value <= 24000, regardless count and blocklength. However, if stride is greater than 24000 then program simply hangs.  The source code is attached and you can simply verify the issue by compiling and running it with the following parameters:

mpicc mpi_tvec_rma.c

mpirun -np 2 ./a.out 10000 2000

Ok

mpirun -np 2 ./a.out 20000 2000

Ok

mpirun -np 2 ./a.out 30000 2000

Hangs

Is there any internal/known limits to the size of MPI_TYPE_VECTOR datatypes?

So, I am really puzzled what is happening here and any help will be greatly appreciated!

With best regards,

Victor.

P.S. The attached code is perfectly runs with the OpenMPI v1.8.2.

P.P.S. Below are given some details about hardware and software setups used:

MPICH2 Version:         1.5

MPICH2 Release date:    Mon Oct  8 14:00:48 CDT 2012

MPICH2 Device:          ch3:nemesis

MPICH2 configure:       --prefix=/opt/mpi/mpich2/ --disable-weak-symbols

MPICH2 CC:      gcc    -O2

MPICH2 CXX:     c++   -O2

MPICH2 F77:     gfortran   -O2

MPICH2 FC:      gfortran   -O2

GCC version 4.7.3


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mpich.org/pipermail/discuss/attachments/20141016/e59532f4/attachment.html>
-------------- next part --------------
_______________________________________________
discuss mailing list     discuss at mpich.org
To manage subscription options or unsubscribe:
https://lists.mpich.org/mailman/listinfo/discuss


More information about the discuss mailing list