Dear developers of MPICH,

I am running MPICH-3.0.4 with a Fortran95-code on a LINUX-cluster using the INTEL-14.0.1 Ftn-compiler.

In that code I employ the shared memory feature (using MPI_WIN_ALLOCATE_SHARED and MPI_WIN_SHARED_QUERY).

It works fine, but nevertheless I detected a little bug in  MPI_WIN_SHARED_QUERY:

     MPI_WIN_SHARED_QUERY(WIN, RANK, SIZE, DISP_UNIT, BASEPTR, IERROR)

The MPI-3.0 Standard document (chapter 11.2, on p. 410)  prescribes that the 4^th parameter  DISP_UNIT  is a result from the call of this sbr.

However, with MPICH no value is returned for DISP_UNIT.

You can easily test that, by setting  DISP_UNIT  to a control number ( e.g.  DISP_UNIT = -7777 )   just before the call of sbr MPI_WIN_SHARED_QUERY.

Just after that sbr-call   the variable  DISP_UNIT  still contains that control number, but should not.

Greetings

Michael Rachner