its possible. but Not a novel idea. hehe. Its a form of HYBRID programming (distributed shared programming). But it needs to be ensured that whether it is beneficial for a given case/problem/code.
On Thu, Jul 22, 2010 at 5:52 PM, Cristobal Navarro <axisch...@gmail.com>wrote: > yes, > i was aware of the big difference hehe. > > now that openMP and openMPI is in talk, i've alwyas wondered if its a > good idea to model a solution on the following way, using both openMP > and openMPI. > suppose you have n nodes, each node has a quadcore, (so you have n*4 > processors) > launch n proceses acorrding to the n nodes available. > set a resource manager like SGE to fill the n*4 slots using round robin. > on each process, make use of the other cores available on the node, > with openMP. > > if this is possible, then on each one could make use fo the shared > memory model locally at each node, evading unnecesary I/O through the > nwetwork, what do you think? > > > > On Thu, Jul 22, 2010 at 5:27 PM, amjad ali <amja...@gmail.com> wrote: > > Hi Cristobal, > > > > Note that the pic in http://dl.dropbox.com/u/6380744/clusterLibs.png > > shows that Scalapack is based on what; it only shows which packages > > Scalapack uses; hence no OpenMP is there. > > > > Also be clear about the difference: > > "OpenMP" is for shared memory parallel programming, while > > "OpenMPI" is an implantation of MPI standard (this list is about OpenMPI > > obviously). > > > > best > > AA. > > > > On Thu, Jul 22, 2010 at 5:06 PM, Cristobal Navarro <axisch...@gmail.com> > > wrote: > >> > >> Thanks > >> > >> im looking at the manual, seems good. > >> i think now the picture is more clear. > >> > >> i have a very custom algorithm, local problem of research, > >> paralelizable, thats where openMPI enters. > >> then, at some point on the program, all the computation traduces to > >> numeric (double) matrix operations, eigenvalues and derivatives. thats > >> where a library like PETSc makes its appearance. or a lower level > >> solution would be GSL and manually implement paralelism with MPI. > >> > >> in case someone chooses, a highlevel library like PETSc and some low > >> level openMPI for its custom algorithms, is there a race for MPI > >> problem? > >> > >> On Thu, Jul 22, 2010 at 3:42 PM, Gus Correa <g...@ldeo.columbia.edu> > wrote: > >> > Hi Cristobal > >> > > >> > You may want to take a look at PETSc, > >> > which has all the machinery for linear algebra that > >> > you need, can easily attach a variety of Linear Algebra packages, > >> > including those in the diagram you sent and more, > >> > builds on top of MPI, and can even build MPI for you, if you prefer. > >> > It has C and Fortran interfaces, and if I remember right, > >> > you can build it alternatively with a C++ interface. > >> > You can choose from real or complex scalars, > >> > depending on your target problem (e.g. if you are going to do > >> > signal/image processing with FFTs, you want complex scalars). > >> > I don't know if it has high level commands to deal with > >> > data structures (like trees that you mentioned), but it may. > >> > > >> > http://www.mcs.anl.gov/petsc/petsc-as/ > >> > > >> > My $0.02 > >> > Gus Correa > >> > --------------------------------------------------------------------- > >> > Gustavo Correa > >> > Lamont-Doherty Earth Observatory - Columbia University > >> > Palisades, NY, 10964-8000 - USA > >> > --------------------------------------------------------------------- > >> > > >> > Cristobal Navarro wrote: > >> >> > >> >> Hello, > >> >> > >> >> i am designing a solution to one of my programs, which mixes some > tree > >> >> generation, matrix operatons, eigenvaluies, among other tasks. > >> >> i have to paralellize all of this for a cluster of 4 nodes (32 > cores), > >> >> and what i first thought was MPI as a blind choice, but after looking > >> >> at this picture > >> >> > >> >> http://dl.dropbox.com/u/6380744/clusterLibs.png ( On the picture, > >> >> openMP is missing.) > >> >> > >> >> i decided to take a break and sit down, think what best suits to my > >> >> needs. > >> >> Adittionally, i am not familiar with Fortran, so i search for C/C++ > >> >> libraries. > >> >> > >> >> what are your experiences, what aspects of your proyect do you > >> >> consider when choosing, is a good practice to mix these libraries in > >> >> one same proyect? > >> >> _______________________________________________ > >> >> 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 > > > > > > _______________________________________________ > > 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 >
