The responsible programmer for this code has conceded the point and we will be replacing all offending examples with the MPI_IN_PLACE solution. Thanks for the input.
T. Rosmond On Thu, 2010-09-16 at 13:56 -0700, Tim Prince wrote: > On 9/16/2010 9:58 AM, David Zhang wrote: > > It's compiler specific I think. I've done this with OpenMPI no > > problem, however on one another cluster with ifort I've gotten error > > messages about not using MPI_IN_PLACE. So I think if it compiles, > > it should work fine. > > > > On Thu, Sep 16, 2010 at 10:01 AM, Tom Rosmond <rosm...@reachone.com> > > wrote: > > I am working with a Fortran 90 code with many MPI calls like > > this: > > > > call mpi_gatherv(x,nsize(rank+1), > > > > mpi_real,x,nsize,nstep,mpi_real,root,mpi_comm_world,mstat) > > > Compiler can't affect what happens here (unless maybe you use x again > somewhere). Maybe you mean MPI library? Intel MPI probably checks > this at run time and issues an error. > I've dealt with run-time errors (which surfaced along with an ifort > upgrade) which caused silent failure (incorrect numerics) on openmpi > but a fatal diagnostic from Intel MPI run-time, due to multiple uses > of the same buffer. Moral: even if it works for you now with > openmpi, you could be setting up for unexpected failure in the future. > -- > Tim Prince > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
