[mvapich-discuss] process limits

[amith rajith mamidala]

Hi Mark,

Can you check if you get this error by setting the environment variable:
VIADEV_USE_SHMEM_COLL to 0 e.g. mpirun_rsh -np N VIADEV_USE_SHMEM_COLL=0
./a.out

-thanks,
Amith

On Tue, 28 Aug 2007, Mark Potts wrote:

> Hi,
>     Is there an effective or hard limit on the number of MVAPICH
>     processes that can be run on a single node?
>
>     Given N cpus, each having M cores, on a single node, I've been told
>     that one can not run more than N*M MVAPICH processes on a single
>     node.  In fact, I observe that if I try to even approach this number
>     with "-np 16" (for a node with N=8 and M=4), I observe a "unable to
>     find child nnnn!" or "Child died" message.  Is this a configuration
>     problem with this system or somehow an expected behavior?
>
>     More pointedly, should oversubscription of cores, np > N*M, on a
>     single node work in MVAPICH?  How about in MVAPICH2?
>
>             regards,
> --
> ***********************************
>  >> Mark J. Potts, PhD
>  >>
>  >> HPC Applications Inc.
>  >> phone: 410-992-8360 Bus
>  >>        410-313-9318 Home
>  >>        443-418-4375 Cell
>  >> email: potts at hpcapplications.com
>  >>        potts at excray.com
> ***********************************
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