Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: Re: [OMPI users] Sharing (not copying) data with OpenMPI?
From: Brian Austin (brianmaustin_at_[hidden])
Date: 2012-04-16 17:16:45


Maybe you meant to search for OpenMP instead of Open-MPI.
You can achieve something close to what you want by using OpenMP for
on-node parallelism and MPI for inter-node communication.
-Brian

On Mon, Apr 16, 2012 at 11:02 AM, George Bosilca <bosilca_at_[hidden]>wrote:

> No currently there is no way in MPI (and subsequently in Open MPI) to
> achieve this. However, in the next version of the MPI standard there will
> be a function allowing processes to shared a memory segment (
> https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/284).
>
> If you like living on the bleeding edge, you can try Brian's branch
> implementing the MPI 3.0 RMA operations (including the shared memory
> segment) from http://svn.open-mpi.org/svn/ompi/tmp-public/mpi3-onesided/.
>
> george.
>
> On Apr 16, 2012, at 09:52 , jody wrote:
>
> > Hi
> >
> > In my application i have to generate a large block of data (several
> > gigs) which subsequently has to be accessed by all processes (read
> > only),
> > Because of its size, it would take quite some time to serialize and
> > send the data to the different processes. Furthermore, i risk
> > running out of memory if this data is instantiated more than once on
> > one machine.
> >
> > Does OpenMPI offer some way of sharing data between processes (on the
> > same machine) without needing to send (and therefore copy) it?
> >
> > Or would i have to do this by means of creating shared memory, writing
> > to it, and then make it accessible for reading by the processes?
> >
> > Thank You
> > Jody
> > _______________________________________________
> > users mailing list
> > users_at_[hidden]
> > http://www.open-mpi.org/mailman/listinfo.cgi/users
>
>
> _______________________________________________
> users mailing list
> users_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/users
>