Archives


- Beowulf
- Beowulf Announce
- Scyld-users
- Beowulf on Debian

MPI/Beowulf vs. SM Programming/OpenMP

Many of your questions may have already been answered in earlier discussions or in the FAQ. The search results page will indicate current discussions as well as past list serves, articles, and papers.

Search

Craig Tierney ctierney at hpti.com
Fri Mar 30 12:47:55 PST 2001


I guess I am confused now.  Are you saying you want to be able
to startup a.out on 3 processors and b.out on 2 processors and
have them talk to each other over MPI (mpich)?

Mpich can do this (I think it is with the -p4pg option).  I use
gm over mpich and I do this as well.  I have to modify the mpirun
script (Myricom's verison doesn't support it) but I have users
that do this now on the system.

Craig

On Fri, Mar 30, 2001 at 11:44:57AM -0800, Mattson, Timothy G wrote:
> Rusty,
> 
> I guess my post wasn't clear enough.  
> 
> I am working with a software vendor.  They need to launch several different
> programs that interact through MPI.  You can do this in PVM, you can do this
> with LAM/MPI, but you can't do this with MPIch.  Or I should say, I don't
> think it can be done with MPIch.  The folks at this company looked into the
> matter and independently reached the same conclustion.
> 
> As I see it, with MPIch, I must have everything in a single program.  Yes,
> the programs can execite readically different pathways so in most cases,
> this doesn't restrict the algorithms I can work with.  There are other
> engineering issues, however, that sometimes force  me to run completely
> different programs that cooperate through MPI.  This is the situation the
> un-named software vendor is faced with.
> 
> So that is is what I meant by my general Multiple Program Multiple Data (or
> MPMD) comment.
> 
> Does this make sense?  Did I get something wrong and it is indeed the case
> that MPIch can handle this situation?  I'd love to be wrong as it would make
> my life simpler if I could do everything with only one version of MPI.
> 
> --Tim  
> 
> -----Original Message-----
> From: Rusty Lusk [mailto:lusk at mcs.anl.gov]
> Sent: Thursday, March 29, 2001 11:15 AM
> To: Mattson, Timothy G
> Cc: 'Chris Richard Adams'; Beowulf (E-mail)
> Subject: Re: MPI/Beowulf vs. SM Programming/OpenMP 
> 
> 
> | A general MPMD algorithm with lots of assynchronous events would be hard
> to
> | do with OpenMP.  (actually, it can be hard with MPIch as well, but then
> you
> | can go with MPI-LAM or PVM).
> 
> Hi Tim,
> 
> I am curious as to what you are referring to with regard to MPICH.  
> 
> Rusty
> 
> 
> _______________________________________________
> Beowulf mailing list, Beowulf at beowulf.org
> To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf

-- 
Craig Tierney (ctierney at hpti.com)
phone: 303-497-3112




More information about the Beowulf mailing list