I just tried this with the mpich master and it seems to work correctly, and there are no zombie processes (though I reduced the number of iterations to 10000, instead of 200000). This was a problem in mpich once upon a time, but that was a few years ago. Are you using the latest version of mpich (3.0.2)? -- Pavan On 03/07/2013 09:44 AM US Central Time, Silvan Br�ndli wrote:

PS: The attached programs are a simplification of my code. They reproduce the zombie problem. Waiting for the 32k zombies takes a while... but I expect the same behaviour as with my original code.

Am I missing something when finishing the called program? I just use MPI_Comm_disconnect and MPI_Finalize.

Best regards Silvan

main.cpp

#include <mpi.h>;

int main(int argc, char *argv[]) { int myrank; int spawnerror; int value = 123; void *buf = &value; MPI_Comm child_comm;

if (MPI_Init(&argc,&argv)!=MPI_SUCCESS) { printf("MPI_Init failed"); }

MPI_Comm_rank(MPI_COMM_WORLD, &myrank);

char* hiargv[] = {"23",NULL}; for(int i = 1; i <= 200000; i++) { value = i; printf("Main before spawn %d\n",i); MPI_Comm_spawn("./hi",hiargv, 1, MPI_INFO_NULL, myrank, MPI_COMM_SELF, &child_comm, &spawnerror); MPI_Send(buf, 1, MPI_INTEGER, 0, 1, child_comm); MPI_Comm_disconnect(&child_comm); }

MPI_Finalize(); return 0; }

hi.cpp:

#include <mpi.h>;

int main(int argc, char** argv) { MPI_Comm parent; MPI_Status status; int err; int value = -1; void* buf= &value;

if (MPI_Init(&argc,&argv)!=MPI_SUCCESS) { printf("MPI_Init failed"); } MPI_Comm_get_parent(&parent); if (parent == MPI_COMM_NULL) printf("No parent!");

MPI_Recv(buf, 1, MPI_INTEGER, 0, MPI_ANY_TAG, parent, &status); MPI_Comm_disconnect(&parent); err = MPI_Finalize(); printf("hi finalized %d %d \n",err, value); return 0; }

On 07.03.2013 12:38, Silvan Br�ndli wrote:

...

Dear all,

again I have a question related to spawning processes. I understand the situation as follows:

My program A spawns program B. Program B spawns program C1, C2 ... C10000 ... Program Cx terminates correctly before Cx+1 is called, however returning 1 to mpiexec. To handle this I use the workaround as described in http://lists.mpich.org/pipermail/discuss/2013-February/000429.html

Now it looks like with every Spawn a "hydra_pmi_proxy" is started, the calling program is mpiexec. When the program Cx is finished this "hydra_pmi_proxy" remains as a zombie until the programs A, B and mpiexec are finished. When approx. 32k of those "hydra_pmi_proxy" exist I get some problems (too many processes or something similar).

What can I do to finish "hydra_pmi_proxy" while my programs A, B and mpiexec are still running?

I'm glad about every hint.

Best regards Silvan

_______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss

-- Pavan Balaji http://www.mcs.anl.gov/~balaji