[Wien] Support of 64-bit MPI addresses in LAPW0

[Oleg Rubel]

Dear Wien2k Users and Developers,

I would like to share my experience in resolving a problem with MPI_ADDRESS in LAPW0 on 64-bit Intel Xeon. I use WIEN2k_08.3 (Release 18/9/2008) compiled with Intel Fortran (version 11.0) and MVAPICH2 1.2.0 2008-11-06. The calculation aborts in LAPW0 saying that "MPI_ADDRESS does not fit in Fortran integer". It is known that MPI_ADDRESS supports 32-bit addresses and the error occurs on 64-bit machines once the address does not fit 32-bit (http://publib.boulder.ibm.com/infocenter/clresctr/vxrx/index.jsp?topic=/com.ibm.cluster.pe432.mpisub.doc/am107_igadd.html). It is proposed to use MPI_GET_ADDRESS instead, which is compatible with 64-bit.

In my case, I get the error not every time, usually for relatively large (> 40 processes) MPI calculation. The problem have gone completely after I changed all instances of MPI_ADDRESS in lapw0.F to MPI_GET_ADDRESS and recompiled the parallel version of LAPW0.

Why not to change to MPI_GET_ADDRESS in the next release?

Sincerely,

Oleg

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Oleg Rubel, PhD
Thunder Bay Regional Research Institute
290 Munro St
Thunder Bay, ON
P7A  7T1, Canada
Phone: +1-807-7663350
E-mail: rubelo at tbh.net
Homepage: http://www.staff.uni-marburg.de/~rubel/