Do you know if there is a limit to the number of MPI_Comm_spawn we can use in
order to launch a program?
I want to start and stop a program several times (with the function
MPI_Comm_spawn) but every time after 31 MPI_Comm_spawn, I get a "segmentation
fault".
Could you give me your point of you to solve this problem?
Thanks
/*file .c : spawned the file Exe*/
#include <stdio.h>
#include <malloc.h>
#include <unistd.h>
#include "mpi.h"
#include <pthread.h>
#include <signal.h>
#include <sys/time.h>
#include <errno.h>
#define EXE_TEST "/home/workspace/test_spaw1/src/Exe"
int main( int argc, char **argv ) {
long *lpBufferMpi;
MPI_Comm lIntercom;
int lErrcode;
MPI_Comm lCommunicateur;
int lRangMain,lRangExe,lMessageEnvoi,lIter,NiveauThreadVoulu,
NiveauThreadObtenu,lTailleBuffer;
int *lpMessageEnvoi=&lMessageEnvoi;
MPI_Status lStatus; /*status de reception*/
lIter=0;
/* MPI environnement */
printf("main*******************************\n");
printf("main : Lancement MPI*\n");
NiveauThreadVoulu = MPI_THREAD_MULTIPLE;
MPI_Init_thread( &argc, &argv, NiveauThreadVoulu, &NiveauThreadObtenu );
lpBufferMpi = calloc( 10000, sizeof(long));
MPI_Buffer_attach( (void*)lpBufferMpi, 10000 * sizeof(long) );
while (lIter<1000){
lIter ++;
lIntercom=(MPI_Comm)-1 ;
MPI_Comm_spawn( EXE_TEST, NULL, 1, MPI_INFO_NULL,
0, MPI_COMM_WORLD, &lIntercom, &lErrcode );
printf( "%i main***MPI_Comm_spawn return : %d\n",lIter, lErrcode );
if(lIntercom == (MPI_Comm)-1 ){
printf("%i Intercom null\n",lIter);
return 0;
}
MPI_Intercomm_merge(lIntercom, 0,&lCommunicateur );
MPI_Comm_rank( lCommunicateur, &lRangMain);
lRangExe=1-lRangMain;
printf("%i main***Rang main : %i Rang exe : %i
\n",lIter,(int)lRangMain,(int)lRangExe);
sleep(2);
}
/* Arret de l'environnement MPI */
lTailleBuffer=10000* sizeof(long);
MPI_Buffer_detach( (void*)lpBufferMpi, &lTailleBuffer );
MPI_Comm_free( &lCommunicateur );
MPI_Finalize( );
free( lpBufferMpi );
printf( "Main = End .\n" );
return 0;
}
/************************************************************************************************/
Exe:
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <malloc.h>
#include <unistd.h> /* pour sleep() */
#include <pthread.h>
#include <semaphore.h>
#include "mpi.h"
int main( int argc, char **argv ) {
/*1)pour communiaction MPI*/
MPI_Comm lCommunicateur; /*communicateur du process*/
MPI_Comm CommParent; /*Communiacteur parent à récupérer*/
int lRank; /*rang du communicateur du process*/
int lRangMain; /*rang du séquenceur si lancé en mode normal*/
int lTailleCommunicateur; /*taille du communicateur;*/
long *lpBufferMpi; /*buffer pour message*/
int lBufferSize; /*taille du buffer*/
/*2) pour les thread*/
int NiveauThreadVoulu, NiveauThreadObtenu;
lCommunicateur = (MPI_Comm)-1;
NiveauThreadVoulu = MPI_THREAD_MULTIPLE;
int erreur = MPI_Init_thread( &argc, &argv, NiveauThreadVoulu,
&NiveauThreadObtenu );
if (erreur!=0){
printf("erreur\n");
free( lpBufferMpi );
return -1;
}
/*2) Attachement à un buffer pour le message*/
lBufferSize=10000 * sizeof(long);
lpBufferMpi = calloc( 10000, sizeof(long));
erreur = MPI_Buffer_attach( (void*)lpBufferMpi, lBufferSize );
if (erreur!=0){
printf("erreur\n");
free( lpBufferMpi );
return -1;
}
printf( "Exe : Lance \n" );
MPI_Comm_get_parent(&CommParent);
MPI_Intercomm_merge( CommParent, 1, &lCommunicateur );
MPI_Comm_rank( lCommunicateur, &lRank );
MPI_Comm_size( lCommunicateur, &lTailleCommunicateur );
lRangMain =1-lRank;
printf( "Exe: lRankExe = %d lRankMain = %d\n", lRank , lRangMain,
lTailleCommunicateur);
sleep(1);
MPI_Buffer_detach( (void*)lpBufferMpi, &lBufferSize );
MPI_Comm_free( &lCommunicateur );
MPI_Finalize( );
free( lpBufferMpi );
printf( "Exe: Fin.\n\n\n" );
}
/************************************************************************************************/
result :
main*******************************
main : Lancement MPI*
1 main***MPI_Comm_spawn return : 0
Exe : Lance
1 main***Rang main : 0 Rang exe : 1
Exe: lRankExe = 1 lRankMain = 0
Exe: Fin.
2 main***MPI_Comm_spawn return : 0
Exe : Lance
2 main***Rang main : 0 Rang exe : 1
Exe: lRankExe = 1 lRankMain = 0
Exe: Fin.
3 main***MPI_Comm_spawn return : 0
Exe : Lance
3 main***Rang main : 0 Rang exe : 1
Exe: lRankExe = 1 lRankMain = 0
Exe: Fin.
....
30 main***MPI_Comm_spawn return : 0
Exe : Lance
30 main***Rang main : 0 Rang exe : 1
Exe: lRankExe = 1 lRankMain = 0
Exe: Fin.
31 main***MPI_Comm_spawn return : 0
Exe : Lance
31 main***Rang main : 0 Rang exe : 1
Exe: lRankExe = 1 lRankMain = 0
Erreur de segmentation
