mpich

Super EDIT: Adding the broadcast step, will result in ncols to get printed by the two processes by the master node (from which I can check the output). But why? I mean, all variables that are broadcast have already a value in the line of their declaration!!! (off-topic image ). I have some code based on this example . I checked that cluster configuration is OK, with this simple program, which also printed the IP of the machine that it would run onto: int main (int argc, char *argv[]) { int rank, size; MPI_Init (&argc, &argv); /* starts MPI */ MPI_Comm_rank (MPI_COMM_WORLD, &rank); /* get

I am trying to get a hybrid OpenMP / MPI job to run so that OpenMP threads are separated by core (only one thread per core). I have seen other answers which use numa-ctl and bash scripts to set environment variables, and I don't want to do this. I would like to be able to do this only by setting OMP_NUM_THREADS and or OMP_PROC_BIND and mpiexec options on the command line. I have tried the following - let's say I want 2 MPI processes that each have 2 OpenMP threads, and each of the threads are run on separate cores, so I want 4 cores total. OMP_PROC_BIND=true OMP_PLACES=cores OMP_NUM_THREADS=2

I have an executable on my Linux box which I know has been compiled either with OpenMPI or MPICH libraries. Question: how to determine which one? The following diagnostic procedure assumes that MPICH/MPICH2 and Open MPI are the only possible MPI implementations that you may have linked with. Other (especially commercial) MPI implementations do exist and may have different library names and/or library symbols. First determine if you linked dynamically: % ldd my_executable linux-vdso.so.1 => (0x00007ffff972c000) libm.so.6 => /lib/libm.so.6 (0x00007f1f3c6cd000) librt.so.1 => /lib/librt.so.1

As per my little knowledge mpirun and mpiexec both are launcher. Can anybody tell the exact difference between mpiexec and mpirun ? mpiexec is defined in the MPI standard (well, the recent versions at least) and I refer you to those (your favourite search engine will find them for you) for details. mpirun is a command implemented by many MPI implementations. It has never, however, been standardised and there have always been, often subtle, differences between implementations. For details see the documentation of the implementation(s) of your choice. And yes, they are both used to launch MPI

I don't understand the error message. I am trying to do is to run a MPICH2 application after I installed mpich2 version 1.4 or 1.5 to /opt/mpich2 (both version failed with the same error). My MPI application was compiled with 1.3 but I am able to run it with mpi 1.4 on another workstation. I am testing it on Ubuntu 12.04. Fatal error in PMPI_Init_thread: Other MPI error, error stack: MPIR_Init_thread(467)..............: MPID_Init(177).....................: channel initialization failed MPIDI_CH3_Init(70).................: MPID_nem_init(319).................: MPID_nem_tcp_init(171).............