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Subject: Re: [OMPI devel] MPI_Comm_spawn under Torque
From: Ralph Castain (rhc_at_[hidden])
Date: 2014-02-20 13:00:30


What OMPI version are you using?

On Feb 20, 2014, at 7:56 AM, Suraj Prabhakaran <suraj.prabhakaran_at_[hidden]> wrote:

> Hello!
>
> I am having problem using MPI_Comm_spawn under torque. It doesn't work when spawning more than 12 processes on various nodes. To be more precise, "sometimes" it works, and "sometimes" it doesn't!
>
> Here is my case. I obtain 5 nodes, 3 cores per node and my $PBS_NODEFILE looks like below.
>
> node1
> node1
> node1
> node2
> node2
> node2
> node3
> node3
> node3
> node4
> node4
> node4
> node5
> node5
> node5
>
> I started a hello program (which just spawns itself and of course, the children don't spawn), with
>
> mpiexec -np 3 ./hello
>
> Spawning 3 more processes (on node 2) - works!
> spawning 6 more processes (node 2 and 3) - works!
> spawning 9 processes (node 2,3,4) - "sometimes" OK, "sometimes" not!
> spawning 12 processes (node 2,3,4,5) - "mostly" not!
>
> I ideally want to spawn about 32 processes with large number of nodes, but this is at the moment impossible. I have attached my hello program to this email.
>
> I will be happy to provide any more info or verbose outputs if you could please tell me what exactly you would like to see.
>
> Best,
> Suraj
>
> <hello.c>_______________________________________________
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