> I assume you mean have them exit without calling MPI_Finalize ...
Yes, thats my idea, exit some processes while the others continue. I am trying
to
use the "orte_allowed_exit_without_sync" flag in the next code (note that the
code
is different):
int main( int argc, char *argv[] )
{
MPI_Init(&argc, &argv);
int myid;
MPI_Comm_rank(MPI_COMM_WORLD, &myid);
if (myid == 0)
{
printf("Exit P0 ...\n");
//With "--mca orte_allowed_exit_without_sync 1" this
//process should die, but not P1, P2 ... , is ok?
exit(0);
}
//Imagine some important job here
sleep(20);
printf("Calling MPI_Finalize() ...\n");
// Process 0 maintain load at 100%.
MPI_Finalize();
return 0;
}
and the cmd:
mpirun --mca orte_allowed_exit_without_sync 1 -hostfile ./hostfile -np 2
--prefix /share/apps/openmpi/gcc/ib/1.7.2 ./a.out
But it does not work, all job fails in the "exit(0)" call. Maybe I don't
undertand your response...
Sorry for not response in order, I have some problems with my
e-mail receiving the Open-MPI mails.
> In my codes, I am using MPI_Send and MPI_Recv functions to notify P0 that
> every other process have finished their own calculations. Maybe you cal
> also use the same method and keep P0 in waiting until it receives some data
> from other processes?
This solution was my first idea, but I can't do it. I use spawned processes and
different communicators for manage "groups" of processes, so the ideal behaviour
is that processes finished and died (or at least don't stay at 100% load) when
their finish their work. Its a bit hard to explain.
----- Mensaje original -----
De: "Ralph Castain" <r...@open-mpi.org>
Para: "Open MPI Users" <us...@open-mpi.org>
Enviados: Viernes, 23 de Mayo 2014 16:39:34
Asunto: Re: [OMPI users] MPI_Finalize() maintains load at 100%.
On May 23, 2014, at 7:21 AM, Iván Cores González <ivan.cor...@udc.es> wrote:
> Hi Ralph,
> Thanks for your response.
> I see your point, I try to change the algorithm but some processes finish
> while the others are still calling MPI functions. I can't avoid this
> behaviour.
> The ideal behavior is the processes go to sleep (or don't use the 100% of
> load) when the MPI_Finalize is called.
>
> For the time being maybe the fastest solution is instert a "manual" sleep
> before the MPI_Finalize.
>
> Another question, Could be possible kill some MPI processes and avoid that
> the mpirun fails? Or this behaviuor is impossible?
I assume you mean have them exit without calling MPI_Finalize, so they don't
block? Technically, yes, though we wouldn't recommend that behavior. You can
add "-mca orte_allowed_exit_without_sync 1" to your cmd line (or set the mca
param in your environment, etc.) and mpirun won't terminate you if a proc exits
without calling MPI_Finalize. We will still, however, terminate the job if (a)
a proc dies by signal (e.g., segfaults), or (b) a proc exits with a non-zero
status, so you'll still have some protection from hangs.
>
> Thanks,
> Ivan Cores
> _______________________________________________
> users mailing list
> us...@open-mpi.org
> http://www.open-mpi.org/mailman/listinfo.cgi/users
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