[mpich-discuss] mpiexec and -n option

[Jain, Rohit]

Hi Pavan,

How is default value determined? 
I am running my application in 2 different environment: shell and grid.
It is working fine in shell, but taking default value of 4 in grid.

I am using hydra.

Regards,
Rohit


-----Original Message-----
From: Pavan Balaji [mailto:balaji at mcs.anl.gov] 
Sent: Monday, August 15, 2011 12:18 PM
To: mpich-discuss at mcs.anl.gov
Cc: Jain, Rohit
Subject: Re: [mpich-discuss] mpiexec and -n option


The default value is the total number of processes specified by the user 
(in the host file) or by the resource manager. In this case, it looks 
like that's 4.

  -- Pavan

On 08/15/2011 01:52 PM, Jain, Rohit wrote:
> I am running mpiexec in following format without any binding:
>
> mpiexec a1.out : a2.out : a3.out
>
> I was expecting that hydra would launch only 3 processes. But, I am
> seeing it is launching 12 processes (4 each). Isn't default value of -n
> is 1?
>
> -verbose option shows following output which confirms my suspicion:
>
> # --version 1.5a1 --iface-ip-env-name MPICH_INTERFACE_HOSTNAME
> --hostname dxyv117 --global-core-map 0,4,0 --filler-process-map 0,4,0
> --global-process-count 12 --auto-cleanup 1 --pmi-rank -1 --pmi-kvsname
> kvs_61149_0 --pmi-process-mapping (vector,(0,1,4)) --ckpoint-num -1
>
> What is causing this behavior?
>
> Regards,
>
> Rohit
>
>
>
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-- 
Pavan Balaji
http://www.mcs.anl.gov/~balaji