george.
On Feb 4, 2008, at 1:29 PM, Edgar Gabriel wrote:
well, but the point is, that the requirement I listed is explicitly mentioned in the chapter about MPI_Reduce. So I would claim, that it trumps (at least) the second citation. (BTW: I am pretty sure that I remember having this discussion early in Open MPI days already :-) ) But maybe that's something for 2.1? Thanks edgar George Bosilca wrote:Well, well, well ... There is really no way to make everybody happy ...When I did the previous commit (where I added the check), Tim Prins pointed out the following 2 paragraphs from the MPI standard.MPI-1.1 s4.9.1 (p113, line 28) says the recvbuf is "significant onlyat root". MPI-1.1 s2.2 (p7, line 7-9) and MPI-2 s2.3 (p7 line 1-3) have the identical text: "Another frequent situation arises when an argument value is needed only by a subset of the processes. When an argument is not significant at a process then an arbitrary value can be passed as argument."As you can see on the second paragraph, the standard claims that an arbitrary value can be passed. george. On Feb 4, 2008, at 8:17 AM, Edgar Gabriel wrote:George,I hate to say this, but I don't think that this is correct. Page 114 inMPI 1 says (in the section about MPI_Reduce) "Thus, all processes provide input buffers and output buffers of the same length, with elements of the same time".The content is only significant at the root, but all processes have toprovide the buffer according to my understanding... Thanks Edgar [email protected] wrote:Author: bosilca Date: 2008-02-03 20:44:41 EST (Sun, 03 Feb 2008) New Revision: 17366 URL: https://svn.open-mpi.org/trac/ompi/changeset/17366 Log: As the receive buffer is only significant at root, limit the check only where it makes sense. Text files modified: trunk/ompi/mpi/c/reduce.c | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) Modified: trunk/ompi/mpi/c/reduce.c= = = = = = = = = = = ===================================================================--- trunk/ompi/mpi/c/reduce.c (original)+++ trunk/ompi/mpi/c/reduce.c 2008-02-03 20:44:41 EST (Sun, 03 Feb2008) @@ -59,9 +59,7 @@ free(msg); return ret; } else if ((ompi_comm_rank(comm) != root && MPI_IN_PLACE == sendbuf) ||- (ompi_comm_rank(comm) == root && MPI_IN_PLACE ==recvbuf)) { - err = MPI_ERR_ARG; - } else if( sendbuf == recvbuf ) { + (ompi_comm_rank(comm) == root && ((MPI_IN_PLACE == recvbuf) || (sendbuf == recvbuf)))) { err = MPI_ERR_ARG; } else { OMPI_CHECK_DATATYPE_FOR_SEND(err, datatype, count); _______________________________________________ svn mailing list [email protected] http://www.open-mpi.org/mailman/listinfo.cgi/svn-- Edgar Gabriel Assistant Professor Parallel Software Technologies Lab http://pstl.cs.uh.edu Department of Computer Science University of Houston Philip G. Hoffman Hall, Room 524 Houston, TX-77204, USA Tel: +1 (713) 743-3857 Fax: +1 (713) 743-3335 _______________________________________________ devel mailing list [email protected] http://www.open-mpi.org/mailman/listinfo.cgi/devel------------------------------------------------------------------------ _______________________________________________ devel mailing list [email protected] http://www.open-mpi.org/mailman/listinfo.cgi/devel-- Edgar Gabriel Assistant Professor Parallel Software Technologies Lab http://pstl.cs.uh.edu Department of Computer Science University of Houston Philip G. Hoffman Hall, Room 524 Houston, TX-77204, USA Tel: +1 (713) 743-3857 Fax: +1 (713) 743-3335 _______________________________________________ devel mailing list [email protected] http://www.open-mpi.org/mailman/listinfo.cgi/devel
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