That's odd. What version of Open MPI are you using?
> On Oct 13, 2020, at 6:34 AM, Diego Zuccato via users
> <users@lists.open-mpi.org> wrote:
>
> Hello all.
>
> I have a problem on a server: launching a job with mpirun fails if I
> request all 32 CPUs (threads, since HT is enabled) but succeeds if I
> only request 30.
>
> The test code is really minimal:
> -8<--
> #include "mpi.h"
> #include <stdio.h>
> #include <stdlib.h>
> #define MASTER 0
>
> int main (int argc, char *argv[])
> {
> int numtasks, taskid, len;
> char hostname[MPI_MAX_PROCESSOR_NAME];
> MPI_Init(&argc, &argv);
> // int provided=0;
> // MPI_Init_thread(&argc, &argv, MPI_THREAD_MULTIPLE, &provided);
> //printf("MPI provided threads: %d\n", provided);
> MPI_Comm_size(MPI_COMM_WORLD, &numtasks);
> MPI_Comm_rank(MPI_COMM_WORLD,&taskid);
>
> if (taskid == MASTER)
> printf("This is an MPI parallel code for Hello World with no
> communication\n");
> //MPI_Barrier(MPI_COMM_WORLD);
>
>
> MPI_Get_processor_name(hostname, &len);
>
> printf ("Hello from task %d on %s!\n", taskid, hostname);
>
> if (taskid == MASTER)
> printf("MASTER: Number of MPI tasks is: %d\n",numtasks);
>
> MPI_Finalize();
>
> printf("END OF CODE from task %d\n", taskid);
> }
> -8<--
> (the commented section is a leftover of one of the tests).
>
> The error is :
> -8<--
> [str957-bl0-03:19637] *** Process received signal ***
> [str957-bl0-03:19637] Signal: Segmentation fault (11)
> [str957-bl0-03:19637] Signal code: Address not mapped (1)
> [str957-bl0-03:19637] Failing at address: 0x7ffff7fac008
> [str957-bl0-03:19637] [ 0]
> /lib/x86_64-linux-gnu/libpthread.so.0(+0x12730)[0x7ffff7e92730]
> [str957-bl0-03:19637] [ 1]
> /usr/lib/x86_64-linux-gnu/pmix/lib/pmix/mca_gds_ds21.so(+0x2936)[0x7ffff646d936]
> [str957-bl0-03:19637] [ 2]
> /usr/lib/x86_64-linux-gnu/libmca_common_dstore.so.1(pmix_common_dstor_init+0x9d3)[0x7ffff6444733]
> [str957-bl0-03:19637] [ 3]
> /usr/lib/x86_64-linux-gnu/pmix/lib/pmix/mca_gds_ds21.so(+0x25b4)[0x7ffff646d5b4]
> [str957-bl0-03:19637] [ 4]
> /usr/lib/x86_64-linux-gnu/libpmix.so.2(pmix_gds_base_select+0x12e)[0x7ffff659346e]
> [str957-bl0-03:19637] [ 5]
> /usr/lib/x86_64-linux-gnu/libpmix.so.2(pmix_rte_init+0x8cd)[0x7ffff654b88d]
> [str957-bl0-03:19637] [ 6]
> /usr/lib/x86_64-linux-gnu/libpmix.so.2(PMIx_Init+0xdc)[0x7ffff6507d7c]
> [str957-bl0-03:19637] [ 7]
> /usr/lib/x86_64-linux-gnu/openmpi/lib/openmpi3/mca_pmix_ext2x.so(ext2x_client_init+0xc4)[0x7ffff6603fe4]
> [str957-bl0-03:19637] [ 8]
> /usr/lib/x86_64-linux-gnu/openmpi/lib/openmpi3/mca_ess_pmi.so(+0x2656)[0x7ffff7fb1656]
> [str957-bl0-03:19637] [ 9]
> /usr/lib/x86_64-linux-gnu/libopen-rte.so.40(orte_init+0x29a)[0x7ffff7c1c11a]
> [str957-bl0-03:19637] [10]
> /usr/lib/x86_64-linux-gnu/libmpi.so.40(ompi_mpi_init+0x252)[0x7ffff7eece62]
> [str957-bl0-03:19637] [11]
> /usr/lib/x86_64-linux-gnu/libmpi.so.40(MPI_Init+0x6e)[0x7ffff7f1b17e]
> [str957-bl0-03:19637] [12] ./mpitest-debug(+0x11c6)[0x5555555551c6]
> [str957-bl0-03:19637] [13]
> /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xeb)[0x7ffff7ce309b]
> [str957-bl0-03:19637] [14] ./mpitest-debug(+0x10da)[0x5555555550da]
> [str957-bl0-03:19637] *** End of error message ***
> -8<--
>
> I'm using Debian stable packages. On other servers there is no problem
> (but there was in the past, and it got "solved" by just installing gdb).
>
> Any hints?
>
> TIA
>
> --
> Diego Zuccato
> DIFA - Dip. di Fisica e Astronomia
> Servizi Informatici
> Alma Mater Studiorum - Università di Bologna
> V.le Berti-Pichat 6/2 - 40127 Bologna - Italy
> tel.: +39 051 20 95786
--
Jeff Squyres
jsquy...@cisco.com
