[mpich-discuss] Running an mpi program that needs to access /dev/mem

[Lee, Eibhlin]

Pavan,

Normally I start smpd when I'm the normal user. This time I did it in root. It then prompted me for a smpd phrase (This happened the first time I ever started it in normal user but the first time it had appeared in root.) The uid=0 now.

However, when I try to execute the program now, in root, it just hangs. With no messages at all! I checked and the cpi example does work when in root.

Eibhlin
________________________________________
From: Pavan Balaji [balaji at mcs.anl.gov]
Sent: 15 June 2013 17:02
To: discuss at mpich.org
Cc: Lee, Eibhlin
Subject: Re: [mpich-discuss] Running an mpi program that needs to access        /dev/mem

On 06/14/2013 04:43 PM, Lee, Eibhlin wrote:
> sorry when I do run mpiexec id the output is
> uid=1000(pi) gid=1000(pi)
> groups=1000(pi),4(adm),20(dialout),24(cdrom),27(sudo),29(audio),44(video),46(plugdev),60(games),100(users),105(netdev),999(input)

This is the crux of the problem.  Your application processes are being
launched as the regular user (uid=1000) instead of as root (uid=0).  I
assume this is how you ran the program; can you confirm?

/* Login as root */
% su

% mpiexec [whatever_options] id

  -- Pavan

--
Pavan Balaji
http://www.mcs.anl.gov/~balaji