I have a server with 12 cores.when I run mpi program with 10 processors.only three processors works.Here are a picture about the problem
why?Is the problem with process schedule?? ------------------ ???????? ------------------ ??????: "Bruno Coutinho";<couti...@dcc.ufmg.br>; ????????: 2013??12??6??(??????) ????11:14 ??????: "Open MPI Users"<us...@open-mpi.org>; ????: Re: [OMPI users]?????? can you help me please ?thanks Probably it was the changing from eager to rendezvous protocols as Jeff said. If you don't know what are these, read this: https://computing.llnl.gov/tutorials/mpi_performance/#Protocols http://blogs.cisco.com/performance/what-is-an-mpi-eager-limit/ http://blogs.cisco.com/performance/eager-limits-part-2/ You can tune eager limit chaning mca parameters btl_tcp_eager_limit (for tcp), btl_self_eager_limit (comunication fron one process to itself), btl_sm_eager_limit (shared memory) and btl_udapl_eager_limit or btl_openib_eager_limit (if you use infiniband). 2013/12/6 Jeff Squyres (jsquyres) <jsquy...@cisco.com> I sent you some further questions yesterday: http://www.open-mpi.org/community/lists/users/2013/12/23158.php On Dec 6, 2013, at 1:35 AM, ???? <781578...@qq.com> wrote: > Here is my 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); > > number here is the size of my array(eg,a or b). > I have try it on my local compute and my rocks cluster.On rocks cluster, one > processor on one frontend node use "MPI_Send" send a message ,other > processors on compute nodes use "MPI_Recv" receive message . > when number is least than 10000,other processors can receive message fast; > but when number is more than 15000,other processors can receive message > slowly > why?? becesue openmpi API ?? or other problems? > > it spends me a few days , I want your help,thanks for all readers. good luck > for you > > > > > ------------------ ???????? ------------------ > ??????: "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 > > _______________________________________________ > 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/ _______________________________________________ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users
