This is a proposal for MPI 2.1, Ballot 4. I'm asking especially Greg Lindahl, the participants of the email-discussion in 2007, to review this proposal. This is a follow up to: Which thread is the funneled thread? in http://www.cs.uiuc.edu/homes/wgropp/projects/parallel/MPI/mpi-errata/index.h... with mail discussion in http://www.cs.uiuc.edu/homes/wgropp/projects/parallel/MPI/mpi-errata/discuss... ___________________________________ Proposal: MPI-2.0 Sect. 8.7.3, MPI_Init_thread, page 196, lines 25-26 read: MPI_THREAD_FUNNELED The process may be multi-threaded, but only the main thread will make MPI calls (all MPI calls are "funneled" to the main thread). but should read: MPI_THREAD_FUNNELED The process may be multi-threaded, but only the main thread will make MPI calls (all MPI calls are "funneled" to the main thread, e.g., by using the OpenMP directive "master" in the application program). ___________________________________ Rationale for this clarification from the email from Greg Lindahl: The existing document doesn't make it clear that the MPI user has to funnel the calls to the main thread; it's not the job of the MPI library. I have seen multiple MPI users confused by this issue, and when I first read this section, I was confused by it, too. ___________________________________ Best regards Rolf Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner_at_[hidden] High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner Nobelstr. 19, D-70550 Stuttgart, Germany . (Office: Allmandring 30)