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Subject: Re: [OMPI users] Option to use only 7 cores out of 8 on each node
From: Addepalli, Srirangam V (srirangam.v.addepalli_at_[hidden])
Date: 2010-03-02 13:10:21


Correct, i was not clear. It spawns more than 7 processes per node. (It spawns 8 of them).
Rangam

________________________________________
From: users-bounces_at_[hidden] [users-bounces_at_[hidden]] On Behalf Of Ralph Castain [rhc_at_[hidden]]
Sent: Tuesday, March 02, 2010 11:55 AM
To: Open MPI Users
Subject: Re: [OMPI users] Option to use only 7 cores out of 8 on each node

When you say "it fails", what do you mean? That it doesn't run at all, or that it still fills each node, or...?

On Tue, Mar 2, 2010 at 9:49 AM, Addepalli, Srirangam V <srirangam.v.addepalli_at_[hidden]<mailto:srirangam.v.addepalli_at_[hidden]>> wrote:
Hello All.
I am trying to run a parallel application that should use one core less than the no of cores that are available on the system. Are there any flags that i can use to specify this.

i tried using the following syntax with machinefile

openmpi-1.4-BM/bin/mpirun -np 14 -npernode 7 -machinefile machinefile ven_nw.e <coll.dt5. This fails. Is there any other way around this. When i get two nodes (with 16 cores) allocated from SGE
and we want to use only 14 cores out of the 16 allocated.

Rangam

My machine file has

compute-9-8.local
compute-9-8.local
compute-9-8.local
compute-9-8.local
compute-9-8.local
compute-9-8.local
compute-9-8.local
compute-9-6.local
compute-9-6.local
compute-9-6.local
compute-9-6.local
compute-9-6.local
compute-9-6.local
compute-9-6.local

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