Durga Choudhury wrote:
A follow-up question (and pardon if this sounds stupid) is this: If I want to make my process multithreaded, BUT only one thread has anything to do with MPI (for example, using OpenMP inside MPI), then the results will be correct EVEN IF #1 or #2 of Eugene holds true. Is this correct? I believe this is thoroughly covered by the standard (though I suppose the same could have been said about my question). In any case, for your situation, initialize MPI with MPI_Init_thread(). Ask for thread level MPI_THREAD_FUNNELED and check that that level is provided. That should cover your case. See the man page for MPI_Init_thread(). My question should not have anything to do with your case. On Tue, Mar 8, 2011 at 12:34 PM, Eugene Loh <eugene....@oracle.com> wrote:Let's say you have multi-threaded MPI processes, you request MPI_THREAD_MULTIPLE and get MPI_THREAD_MULTIPLE, and you use the self,sm,tcp BTLs (which have some degree of threading support). Is it okay to have an [MPI_Isend|MPI_Irecv] on one thread be completed by an MPI_Wait on another thread? I'm assuming some sort of synchronization and memory barrier/flush in between to protect against funny race conditions.If it makes things any easier on you, we can do this multiple-choice style: 1) Forbidden by the MPI standard. 2) Not forbidden by the MPI standard, but will not work with OMPI (not even with the BTLs that claim to be multi-threaded). 3) Works well with OMPI (provided you use a BTL that's multi-threaded). It's looking like #2 to me, but I'm not sure. _______________________________________________ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users_______________________________________________ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users |
- [OMPI users] multi-threaded programming Eugene Loh
- Re: [OMPI users] multi-threaded programming Durga Choudhury
- Re: [OMPI users] multi-threaded programming Eugene Loh
- Re: [OMPI users] multi-threaded programming Jeff Squyres