ok. Thx for your answer. The documentation was not clear on this subject. Cheers Guillaume
Le 29/04/2013 17:49, George Bosilca a écrit : > No, the root processor can be different for every broadcast, but for a same > broadcast every process involved must know who the root is. That's the only > condition MPI imposes. > > George. > > On Apr 29, 2013, at 13:15 , giggzounet <giggzou...@gmail.com> wrote: > >> Hi, >> >> I'm new on this list. I'm using MPI for years but I don't have written a >> lot of code with MPI. Therefore is my question perhaps ridiculous: >> >> I'm using a Computational Fluid Mechanics (CFD) Solver. This Solver uses >> MPI to exchange the data between the different partitions. In this >> solver the "root processor" is always the processor 1. So this proc >> reads the input, broadcast a lot of things and writes the output. >> >> During a time step the solver computes the reference pressure at a >> point. This computation is done on a processor, which may not be the >> root processor. Therefore after the computation a broadcast of the value >> is necessary. For the moment in the code the broadcast is done with the >> processor, where the reference pressure is computed, as root processor >> (and not with the standard "root processor"). >> >> Is it false ? Must the root processor be the same during a computation >> for all broadcasts ? >> >> Best regards, >> Guillaume >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users
