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Subject: Re: [OMPI devel] mpirun oddity w/ PBS on an SGI UV
From: Ralph Castain (rhc_at_[hidden])
Date: 2014-01-31 18:20:29


On Jan 31, 2014, at 3:13 PM, Paul Hargrove <phhargrove_at_[hidden]> wrote:

> Ralph,
>
> As I said this is NOT a cluster - it is a 4k-core shared memory machine.

I understood - that wasn't the nature of my question

> TORQUE is allocating cpus (time-shared mode, IIRC), not nodes.
> So, there is always exactly one line in $PBS_NODESFILE.

Interesting - because that isn't the standard way Torque behaves. It is supposed to put one line/slot in the nodefile, each line containing the name of the node. Clearly, SGI has reconfigured Torque to do something different.

>
> The system runs as 2 partitions of 2k-cores each.
> So, the contents odf$PBS_NODESFILE has exactly 2 possible values, each 1 line.
>
> The values of PBS_PPN and PBS_NCPUS both reflect the size of the allocation.
>
> At a minimum, shouldn't Open MPI be multiplying the lines in $PBS_NODESFILE by the value of $PBS_PPN?

No, as above, that isn't the way Torque generally behaves. It would appear that we need a "switch" here to handle SGI's modifications. Should be doable - just haven't had anyone using an SGI machine before :-)

>
> Additionally, when I try "mpirun -npernode 16 ./ring_c" I am still told there are not enough slots.
> Shouldn't that be working with 1 line is $PBS_NODESFILE?
>
> -Paul
>
>
>
>
> On Fri, Jan 31, 2014 at 2:47 PM, Ralph Castain <rhc_at_[hidden]> wrote:
> We read the nodes from the PBS_NODEFILE, Paul - can you pass that along?
>
> On Jan 31, 2014, at 2:33 PM, Paul Hargrove <phhargrove_at_[hidden]> wrote:
>
>> I am trying to test the trunk on an SGI UV (to validate Nathan's port of btl:vader to SGI's variant of xpmem).
>>
>> At configure time, PBS's TM support was correctly located.
>>
>> My PBS batch script includes
>> #PBS -l ncpus=16
>> because that is what this installation requires (not nodes, mppnodes, or anything like that).
>> One is allocating cpus on a large shared-memory machine, not a set of nodes in a cluster.
>>
>> However, this appears to be causing mpirun to think I have just 1 slot:
>>
>> + mpirun -np 2 ./ring_c
>> --------------------------------------------------------------------------
>> There are not enough slots available in the system to satisfy the 2 slots
>> that were requested by the application:
>> ./ring_c
>>
>> Either request fewer slots for your application, or make more slots available
>> for use.
>> --------------------------------------------------------------------------
>>
>> In case they contain useful info, here are the PBS env vars in the job:
>>
>> PBS_HT_NCPUS=32
>> PBS_VERSION=TORQUE-2.3.13
>> PBS_JOBNAME=qs
>> PBS_ENVIRONMENT=PBS_BATCH
>> PBS_HOME=/var/spool/torque
>> PBS_O_WORKDIR=/usr/users/6/hargrove/SCRATCH/OMPI/openmpi-trunk-linux-x86_64-uv-trunk/BLD/examples
>> PBS_PPN=16
>> PBS_TASKNUM=1
>> PBS_O_HOME=/usr/users/6/hargrove
>> PBS_MOMPORT=15003
>> PBS_O_QUEUE=debug
>> PBS_O_LOGNAME=hargrove
>> PBS_O_LANG=en_US.UTF-8
>> PBS_JOBCOOKIE=9EEF5DF75FA705A241FEF66EDFE01C5B
>> PBS_NODENUM=0
>> PBS_O_SHELL=/usr/psc/shells/bash
>> PBS_SERVER=tg-login1.blacklight.psc.teragrid.org
>> PBS_JOBID=314827.tg-login1.blacklight.psc.teragrid.org
>> PBS_NCPUS=16
>> PBS_O_HOST=tg-login1.blacklight.psc.teragrid.org
>> PBS_VNODENUM=0
>> PBS_QUEUE=debug_r1
>> PBS_O_MAIL=/var/mail/hargrove
>> PBS_NODEFILE=/var/spool/torque/aux//314827.tg-login1.blacklight.psc.teragrid.org
>> PBS_O_PATH=[...removed...]
>>
>> If any additional info is needed to help make mpirun "just work", please let me know.
>>
>> However, at this point I am mostly interested in any work-arounds that will let me run something other than a singleton on this system.
>>
>> -Paul
>>
>> --
>> Paul H. Hargrove PHHargrove_at_[hidden]
>> Future Technologies Group
>> Computer and Data Sciences Department Tel: +1-510-495-2352
>> Lawrence Berkeley National Laboratory Fax: +1-510-486-6900
>> _______________________________________________
>> devel mailing list
>> devel_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/devel
>
>
> _______________________________________________
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>
>
> --
> Paul H. Hargrove PHHargrove_at_[hidden]
> Future Technologies Group
> Computer and Data Sciences Department Tel: +1-510-495-2352
> Lawrence Berkeley National Laboratory Fax: +1-510-486-6900
> _______________________________________________
> devel mailing list
> devel_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/devel