Sorry for the super-late reply. :-\ Yes, ERR_TRUNCATE means that the receiver didn't have a large enough buffer.
Have you tried upgrading to a newer version of Open MPI? 1.4.3 is the current stable release (I have a very dim and not guaranteed to be correct recollection that we fixed something in the internals of collectives somewhere with regards to ERR_TRUNCATE...?). On Apr 25, 2011, at 4:44 PM, Wei Hao wrote: > Hi: > > I'm running openmpi 1.2.8. I'm working on a project where one part involves > communicating an integer, representing the number of data points I'm keeping > track of, to all the processors. The line is simple: > > MPI_Allreduce(&np,&geo_N,1,MPI_INT,MPI_MAX,MPI_COMM_WORLD); > > where np and geo_N are integers, np is the result of a local calculation, and > geo_N has been declared on all the processors. geo_N is nondecreasing. This > line works the first time I call it (geo_N goes from 0 to some other > integer), but if I call it later in the program, I get the following error: > > > [woodhen-039:26189] *** An error occurred in MPI_Allreduce > [woodhen-039:26189] *** on communicator MPI_COMM_WORLD > [woodhen-039:26189] *** MPI_ERR_TRUNCATE: message truncated > [woodhen-039:26189] *** MPI_ERRORS_ARE_FATAL (goodbye) > > > As I understand it, MPI_ERR_TRUNCATE means that the output buffer is too > small, but I'm not sure where I've made a mistake. It's particularly > frustrating because it seems to work fine the first time. Does anyone have > any thoughts? > > Thanks > Wei > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/