You are right Dave, FUNNELED allows the application to have multiple threads but only the man thread calls MPI.
An OpenMP/MPI hybrid program that makes MPI calls only in between parallel sections is usually a FUNNELED user of MPI Thanks Dick Treumann - MPI Team IBM Systems & Technology Group Dept X2ZA / MS P963 -- 2455 South Road -- Poughkeepsie, NY 12601 Tele (845) 433-7846 Fax (845) 433-8363 From: Dave Goodell <good...@mcs.anl.gov> To: Open MPI Users <us...@open-mpi.org> Date: 03/03/2010 03:08 PM Subject: Re: [OMPI users] MPI_Init() and MPI_Init_thread() Sent by: users-boun...@open-mpi.org On Mar 3, 2010, at 11:35 AM, Richard Treumann wrote: > If the application will make MPI calls from multiple threads and > MPI_INIT_THREAD has returned FUNNELED, the application must be > willing to take the steps that ensure there will never be concurrent > calls to MPI from the threads. The threads will take turns - without > fail. > Minor nitpick: if the implementation returns FUNNELED, only the main thread (basically the thread that called MPI_INIT_THREAD, see MPI-2.2 pg 386 for def'n) may make MPI calls. Dick's paragraph above is correct if you replace FUNNELED with SERIALIZED. -Dave _______________________________________________ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users