Hi, Processes are not spawned by MPI_Init. They are spawned before by some applications between your mpirun call and when your program starts. When it does, you already have all MPI processes (you can check by adding a sleep or something like that), but they are not synchronized and do not know each other. This is what MPI_Init is used for.
Matthieu Brucher 2011/12/14 Dmitry N. Mikushin <maemar...@gmail.com> > Dear colleagues, > > For GPU Winter School powered by Moscow State University cluster > "Lomonosov", the OpenMPI 1.7 was built to test and popularize CUDA > capabilities of MPI. There is one strange warning I cannot understand: > OpenMPI runtime suggests to initialize CUDA prior to MPI_Init. Sorry, > but how could it be? I thought processes are spawned during MPI_Init, > and such context will be created on the very first root process. Why > do we need existing CUDA context before MPI_Init? I think there was no > such error in previous versions. > > Thanks, > - D. > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users > -- Information System Engineer, Ph.D. Blog: http://matt.eifelle.com LinkedIn: http://www.linkedin.com/in/matthieubrucher
