Abe-san, MPI_Isend followed by MPI_Wait is equivalent to MPI_Send
Depending on message size and inflight messages, that can deadlock if two tasks send to each other and no recv has been posted. Cheers, Gilles ABE Hiroshi <hab...@gmail.com> wrote: >Dear All, > >Installed openmpi 1.10.0 and gcc-5.2 using Fink (http://www.finkproject.org) >but nothing is changed with my code. > >Regarding the MPI_Finalize error in my previous mail, it should be my fault. I >had removed all mpi stuff in /usr/local/ manually and the openmpi-1.10.0 had >been installed then the error message didn’t appear now. Maybe some old >version of openmpi stuff still remained there. > >Anyway, I found the reason of my problem. The code is : > >void >Block::MPISendEqualInterChangeData( DIRECTION dir, int rank, int id ) { > > GetEqualInterChangeData( dir, cf[0] ); > > int N = GetNumGrid(); > int nb = 6*N*N*1; > nb = 1010; >// float *buf = new float[ nb ]; > float *buf = (float *)malloc( sizeof(float)*nb); > for( int i = 0; i < nb; i++ ) buf[i] = 0.0; > > MPI_Request req; > MPI_Status status; > > int tag = 100 * id + (int)dir; > > MPI_Isend( buf, nb, MPI_REAL4, rank, tag, MPI_COMM_WORLD, &req ); > MPI_Wait( &req, &status ); > >// delete [] buf; > free( buf ); >} > >This works. If the “nb” value changes to more than “1010”, MPI_Wait will stall. >This means the upper limit of MPI_Isend would be 4 x 1010 = 4040 bytes. > >If this is true, is there any way to increase this?. I guess this should be >wrong and there should be something wrong with my system. > >Any idea and suggestions are really appreciated. > >Thank you. > >2015/11/03 8:05、Jeff Squyres (jsquyres) <jsquy...@cisco.com> のメール： > >> On Oct 29, 2015, at 10:24 PM, ABE Hiroshi <hab...@gmail.com> wrote: >>> >>> Regarding my code I mentioned in my original mail, the behaviour is very >>> weird. MPI_Isend is called from the different named function, it works. >>> And I wrote a sample program to try to reproduce my problem but it works >>> fine, except the problem of MPI_Finalize. >>> >>> So I decided to make gcc-5.2 and make openmpi on it, which seems to be a >>> recommendation of the FINK project. >> >> Ok. Per the prior mail, if you can make a small reproducer, that would be >> most helpful in tracking down the issue. >> >> Thanks! > >ABE Hiroshi > from Tokorozawa, JAPAN > >_______________________________________________ >users mailing list >us...@open-mpi.org >Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users >Link to this post: >http://www.open-mpi.org/community/lists/users/2015/11/27985.php
