[mvapich-discuss] process limits

[Mark Potts]

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
***********************************