three nodes with 3 ranks.and number is the size of the array ?? int*a=(int*)malloc(sizeof(int)*number); MPI_Send(a,number, MPI_INT, 1, 1,MPI_COMM_WORLD);
int*b=(int*)malloc(sizeof(int)*number); MPI_Recv(b, number, MPI_INT, 0, MPI_ANY_TAG, MPI_COMM_WORLD, &status); why???? is the limite of the speed between MPI_Send and MPI_Recv?????? ------------------ ???????? ------------------ ??????: "Ralph Castain";<r...@open-mpi.org>; ????????: 2013??12??5??(??????) ????6:52 ??????: "Open MPI Users"<us...@open-mpi.org>; ????: Re: [OMPI users] can you help me please ?thanks You are running 15000 ranks on two nodes?? My best guess is that you are swapping like crazy as your memory footprint problem exceeds available physical memory. On Thu, Dec 5, 2013 at 1:04 AM, ???? <781578...@qq.com> wrote: My ROCKS cluster includes one frontend and two compute nodes.In my program,I have use the openmpi API such as MPI_Send and MPI_Recv . but when I run the progam with 3 processors . one processor send a message ,other receive message .here are some code. int*a=(int*)malloc(sizeof(int)*number); MPI_Send(a,number, MPI_INT, 1, 1,MPI_COMM_WORLD); int*b=(int*)malloc(sizeof(int)*number); MPI_Recv(b, number, MPI_INT, 0, MPI_ANY_TAG, MPI_COMM_WORLD, &status); when number is least than 10000,it runs fast. but number is more than 15000,it runs slowly why?? becesue openmpi API ?? or other problems? ------------------ ???????? ------------------ ??????: "Ralph Castain";<r...@open-mpi.org>; ????????: 2013??12??3??(??????) ????1:39 ??????: "Open MPI Users"<us...@open-mpi.org>; ????: Re: [OMPI users] can you help me please ?thanks On Mon, Dec 2, 2013 at 9:23 PM, ???? <781578...@qq.com> wrote: A simple program at my 4-node ROCKS cluster runs fine with command: /opt/openmpi/bin/mpirun -np 4 -machinefile machines ./sort_mpi6 Another bigger programs runs fine on the head node only with command: cd ./sphere; /opt/openmpi/bin/mpirun -np 4 ../bin/sort_mpi6 But with the command: cd /sphere; /opt/openmpi/bin/mpirun -np 4 -machinefile ../machines ../bin/sort_mpi6 It gives output that: ../bin/sort_mpi6: error while loading shared libraries: libgdal.so.1: cannot open shared object file: No such file or directory ../bin/sort_mpi6: error while loading shared libraries: libgdal.so.1: cannot open shared object file: No such file or directory ../bin/sort_mpi6: error while loading shared libraries: libgdal.so.1: cannot open shared object file: No such file or directory _______________________________________________ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users _______________________________________________ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users
