This bug had the opportunity to appear in all collectives supporting intercommunicators where we check the receive buffer(s) consistency. In addition to what Jeff fixed already, I fix it in ALLTOALLV, ALLTOALLW and GATHER.
george. On May 24, 2012, at 09:37 , Jeff Squyres wrote: > On May 24, 2012, at 9:28 AM, Jeff Squyres wrote: > >> So I checked them all, and I found SCATTERV, GATHERV, and REDUCE_SCATTER all >> had the issue. Now fixed on the trunk, and will be in 1.6.1. > > > I forgot to mention -- this issue exists waaay back in the Open MPI code > base. I spot-checked Open MPI 1.2.0 and see it there, too. > > To be clear: this particular bug only shows itself when you invoke > ALLGATHERV, GATHERV, SCATTERV, or REDUCE_SCATTER on an intercommunicator > where the sizes of the two groups are unequal. Whether the problem shows > itself or not is rather random (i.e., it depends on how "safe" the memory is > after the recvcounts array). FWIW, you can workaround this bug by setting > the MCA parameter "mpi_param_check" to 0, which disables all MPI function > parameter checking. That may not be attractive in some cases, of course. > > More specifically: since this problem has been in the OMPI code base for > *years* (possibly since 1.0 -- but I'm not going to bother to check), it > shows how little real-world applications actually use this specific > functionality. Don't get me wrong -- I'm *very* thankful to the mpi4py > community for raising this issue, and I'm glad to get it fixed! But it does > show that there are dark, dusty corners in MPI functionality where few bother > to tread. :-) > > -- > Jeff Squyres > jsquy...@cisco.com > For corporate legal information go to: > http://www.cisco.com/web/about/doing_business/legal/cri/ > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
