Gus, I believe your first assumption is correct. Unfortunately it just seemed to hang. I think this might be because each one is being made to have the same rank... It may already be obvious but this is the first time I am using Linux. I had tried sudo $(which mpiexec ....) and sudo $(which mpiexec) ... both without success. Is putting the full path to it similar to/is a symlink? (This still doesn't make main have super user privileges though.) Eibhlin ________________________________________ From: [email protected] [[email protected]] on behalf of Gus Correa [[email protected]] Sent: 13 June 2013 15:37 To: Discuss Mpich Subject: Re: [mpich-discuss] Running an mpi program that needs to access /dev/mem Hi Lee How about replacing "~/main" in the mpiexec command line by one-liner script? Say, "sudo_main.sh", something like this: #! /bin/bash sudo ~/main After all, it is "main" that accesses /dev/mem, and needs "sudo" permissions, not mpiexec, right? [Or do the mpiexec-launched processes inherit the "sudo" stuff from mpiexec?] Not related, but, instead of putting mpiexec in /usr/bin, can't you just use the full path to it? I hope this helps, Gus Correa On 06/13/2013 10:09 AM, Lee, Eibhlin wrote:

Pavan, I had a lot of trouble getting hydra to work without having to enter a password/passphrase. I saw the option to pass a phrase in the mpich installers guide. I eventually found that for that command you needed to use the smpd process manager. That's the only reason I chose smpd over hydra. As to your other suggestion. I ran ./main and the same error (Can't open /dev/mem...) appeared. sudo ./main works but of course without multiple processes. Eibhlin ________________________________________ From: [email protected] [[email protected]] on behalf of Pavan Balaji [[email protected]] Sent: 13 June 2013 14:34 To: [email protected] Subject: Re: [mpich-discuss] Running an mpi program that needs to access /dev/mem

I just saw your older email. Why are you using smpd instead of the default process manager (hydra)?

-- Pavan

On 06/13/2013 08:05 AM, Pavan Balaji wrote:

...

What's "-phrase"? That's not a recognized option. I'm not sure where the /dev/mem check is coming from. Try running ~/main without mpiexec first.

-- Pavan

On 06/13/2013 06:56 AM, Lee, Eibhlin wrote:

...

Hello all,

I am trying to use two raspberry-pi to sample and then process some data. The first process samples while the second processes and vice versa. To do this I use gpio and also mpich-3.0.4 with the process manager smpd. I have successfully run cpi on both machines (from the master machine). I have also managed to run a similar program but without the MPI, this involved compiling with gcc and when running putting sudo in front of the binary file.

When I combine these two processes I get various error messages. For input: mpiexec -phrase cat -machinefile machinefile -n 2 ~/main the error is: Can't open /dev/mem Did you forget to use 'sudo .. ?'

For input: sudo mpiexec -phrase cat -machinefile machinefile -n 2 ~/main the error is: sudo: mpiexec: Command not found

I therefore put mpiexec into /usr/bin

now for input: sudo mpiexec -phrase cat -machinefile machinefile -n 2 ~/main the error is: Can't open /dev/mem Did you forget to use 'sudo .. ?'

Does anyone know how I can work around this? Thanks, Eibhlin

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-- Pavan Balaji http://www.mcs.anl.gov/~balaji _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss

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