Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: Re: [OMPI users] OpenMPI runtime-specific environment variable?
From: Adams, Brian M (briadam_at_[hidden])
Date: 2008-10-24 19:01:50

> -----Original Message-----
> From: users-bounces_at_[hidden]
> [mailto:users-bounces_at_[hidden]] On Behalf Of Ralph Castain
> Sent: Wednesday, October 22, 2008 8:02 AM
> To: Open MPI Users
> Subject: Re: [OMPI users] OpenMPI runtime-specific
> environment variable?
> What I think Brian is trying to do is detect that his code
> was not launched by mpirun -prior- to calling MPI_Init so he
> can decide if he wants to do that at all. Checking for the
> enviro params I suggested is a good way to do it - I'm not
> sure that adding another one really helps. The key issue is
> having something he can rely on, and I think the ones I
> suggested are probably his best bet for OMPI.

Just closing the loop on this thread -- again thanks for all the good discussion. Ralph's comment here is exactly right. On some platforms, e.g., AIX/Poe/IBM MPI, we've historically been bitten as it's not safe to call MPI_Init when not running inside a job submitted to the queue and running in an MPI environment. I realize it's our (perhaps stubborn) choice to distribute MPI-linked binaries that have to work correctly in both serial (not just mpirun -np 1) and MPI-parallel mdoes, and that complicates things.