Thanks Pavan and Wesley for your answers.
Matthieu
----- Mail original -----
> De: "Wesley Bland" <wbland(a)mcs.anl.gov>
> À: discuss(a)mpich.org
> Envoyé: Vendredi 2 Août 2013 17:27:44
> Objet: Re: [mpich-discuss] MPI_Comm_spawn info argument
> To answer your second question since Pavan covered #1, once the
> parent application spawns the child process(es), it gets back a new
> communicator called an intercommunicator. You can do communication
> on that communicator similarly to a normal communicator including an
> MPI_BARRIER. So when your child is done, you can call a barrier on
> both ends and be sure that you're done.
> Wesley
> On Friday, August 2, 2013 at 4:03 PM, Matthieu Dorier wrote:
> > Hi,
>
> > Using MPI_Comm_spawn I'd like to know how to specify the list of
> > hosts on which to spawn the new processes. The standard
> > http://www.mpi-forum.org/docs/mpi-3.0/mpi30-report.pdf ) says that
> > the info field have some reserved keys, but nothing to actually
> > give
> > the list of hostnames. The closest key is "host" but it seems to
> > designate a single host, not a set, and not even the number of
> > process per host.
>
> > What would be the keys for that in mpich and would they be
> > understood
> > my other implementation (e.g. OpenMPI)?
>
> > Also another question related to MPI_Comm_spawn: how can a parent
> > application be aware that the application it spawned terminated?
>
> > And what happens when the parent application exits before the
> > spawned
> > one?
>
> > Thanks,
>
> > Matthieu Dorier
>
> > PhD student at ENS Cachan Brittany and IRISA
>
> > http://people.irisa.fr/Matthieu.Dorier
>
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>
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To answer your second question since Pavan covered #1, once the parent application spawns the child process(es), it gets back a new communicator called an intercommunicator. You can do communication on that communicator similarly to a normal communicator including an MPI_BARRIER. So when your child is done, you can call a barrier on both ends and be sure that you're done.
Wesley
On Friday, August 2, 2013 at 4:03 PM, Matthieu Dorier wrote:
> Hi,
>
> Using MPI_Comm_spawn I'd like to know how to specify the list of hosts on which to spawn the new processes. The standard http://www.mpi-forum.org/docs/mpi-3.0/mpi30-report.pdf) says that the info field have some reserved keys, but nothing to actually give the list of hostnames. The closest key is "host" but it seems to designate a single host, not a set, and not even the number of process per host.
>
> What would be the keys for that in mpich and would they be understood my other implementation (e.g. OpenMPI)?
>
> Also another question related to MPI_Comm_spawn: how can a parent application be aware that the application it spawned terminated?
> And what happens when the parent application exits before the spawned one?
>
> Thanks,
>
> Matthieu Dorier
> PhD student at ENS Cachan Brittany and IRISA
> http://people.irisa.fr/Matthieu.Dorier
> _______________________________________________
> discuss mailing list discuss(a)mpich.org (mailto:[email protected])
> To manage subscription options or unsubscribe:
> https://lists.mpich.org/mailman/listinfo/discuss
>
>
Matthieu,
MPICH's default process manager also supports the "hostfile" and "hosts"
options, but that's not a part of the MPI standard, so there's no
guarantee that other MPI implementations (or even other process managers
within mpich) will support it.
-- Pavan
On 08/02/2013 04:03 PM, Matthieu Dorier wrote:
> Hi,
>
> Using MPI_Comm_spawn I'd like to know how to specify the list of hosts
> on which to spawn the new processes. The standard
> http://www.mpi-forum.org/docs/mpi-3.0/mpi30-report.pdf) says that the
> info field have some reserved keys, but nothing to actually give the
> list of hostnames. The closest key is "host" but it seems to designate a
> single host, not a set, and not even the number of process per host.
>
> What would be the keys for that in mpich and would they be understood my
> other implementation (e.g. OpenMPI)?
>
> Also another question related to MPI_Comm_spawn: how can a parent
> application be aware that the application it spawned terminated?
> And what happens when the parent application exits before the spawned one?
>
> Thanks,
>
> Matthieu Dorier
> PhD student at ENS Cachan Brittany and IRISA
> http://people.irisa.fr/Matthieu.Dorier
>
>
> _______________________________________________
> discuss mailing list discuss(a)mpich.org
> To manage subscription options or unsubscribe:
> https://lists.mpich.org/mailman/listinfo/discuss
>
--
Pavan Balaji
http://www.mcs.anl.gov/~balaji
Hi,
Using MPI_Comm_spawn I'd like to know how to specify the list of hosts on which to spawn the new processes. The standard http://www.mpi-forum.org/docs/mpi-3.0/mpi30-report.pdf) says that the info field have some reserved keys, but nothing to actually give the list of hostnames. The closest key is "host" but it seems to designate a single host, not a set, and not even the number of process per host.
What would be the keys for that in mpich and would they be understood my other implementation (e.g. OpenMPI)?
Also another question related to MPI_Comm_spawn: how can a parent application be aware that the application it spawned terminated?
And what happens when the parent application exits before the spawned one?
Thanks,
Matthieu Dorier
PhD student at ENS Cachan Brittany and IRISA
http://people.irisa.fr/Matthieu.Dorier
