Hi Thank You all for your replies. I'll certainly look into the MPI 3.0 RMA link (out of pure interest) but i am afraid i can't go bleeding edge, because my application will also have to run on an other machine.
As to OpenMP: i already make use of OpenMP in some places (for instance for the creation of the large data block), but unfortunately my main application is not well suited for OpenMP parallelization.. I guess i'll have to take more detailed look at my problem to see if i can restructure it in a good way... Thank You Jody On Mon, Apr 16, 2012 at 11:16 PM, Brian Austin <brianmaus...@gmail.com> wrote: > 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 <bosi...@eecs.utk.edu> > 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 >> > us...@open-mpi.org >> > http://www.open-mpi.org/mailman/listinfo.cgi/users >> >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users > > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
