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Subject: Re: [OMPI users] Core ids not coming properly
From: Brice Goglin (Brice.Goglin_at_[hidden])
Date: 2013-02-15 11:46:25


IntelMPI binds processes by default, while OMPI doesn't. What's your
mpiexec/mpirun command-line?

Brice

Le 15/02/2013 17:34, Kranthi Kumar a écrit :
> Hello Sir
>
> Here below is the code which I wrote using hwloc for getting the
> bindings of the processes.
> I tested this code on SDSC Gordon Super Computer which has Open MPI
> 1.4.3 and on TACC Stampede which uses intel's MPI library IMPI.
> With Open MPI I get all the core ids for all the processes as 0. Using
> Intel MPI library I get different coreids. I tried even binding the
> processes
> in the command line using taskset. Open MPI gives me core id 0 for all
> the processes whereas IMPI gives me correct bindings.
> Please look into this
>
>
> #include <stdio.h>
> #include <sched.h>
> #include <math.h>
> #include "mpi.h"
> #include <hwloc.h>
> int main(int argc, char* argv[])
> {
> int rank, size;
> cpu_set_t mask;
> long num;
> int proc_num(long num);
>
> hwloc_topology_t topology;
> hwloc_cpuset_t cpuset;
> hwloc_obj_t obj;
>
> MPI_Init(&argc, &argv);
> MPI_Comm_rank(MPI_COMM_WORLD, &rank);
> MPI_Comm_size(MPI_COMM_WORLD, &size);
>
> hwloc_topology_init ( &topology);
> hwloc_topology_load ( topology);
>
> hwloc_bitmap_t set = hwloc_bitmap_alloc();
> hwloc_obj_t pu;
> int err;
>
> err = hwloc_get_proc_cpubind(topology, getpid(), set,
> HWLOC_CPUBIND_PROCESS);
> if (err) {
> printf ("Error Cannot find\n"), exit(1);
> }
>
> pu = hwloc_get_pu_obj_by_os_index(topology, hwloc_bitmap_first(set));
> printf ("Hello World, I am %d and pid: %d
> coreid:%d\n",rank,getpid(),hwloc_bitmap_first(set));
>
> hwloc_bitmap_free(set);
> MPI_Finalize();
> fclose(stdout);
> return 0;
> }
> Thank You
> --
> Kranthi
>
>
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