Hi, Am 21.09.2010 um 10:54 schrieb Mikael Lavoie:
> Sorry, but i get lost in what i wanna do, i have build a small home cluster > with Pelican_HPC, that user openMPI, and i was trying to find a way to get a > multithreaded program work in a multiprocess way without taking the time to > learn MPI. And my vision was a sort of wrapper that take C posix app src > code, and convert it from pthread to a multiprocessMPI app. But the problem > is the remote memory access, that will only be implemented in MPI 3.0(for > what i've read of it). > > So, after 12 hour of intensive reading about MPI and POSIX, the best way to > deal with my problem(running a C pthreaded app in my cluster) is to convert > the src in a SPMD way. > I didn't mentionned that basicly, my prog open huge text file, take each > string and process it through lot's of cryptographic iteration and then save > the result in an output.out like file. > So i will need to make the master process split the input file and then send > them as input for the worker process. > > But if you or someone else know a kind of interpretor like program to run a > multithreaded C program and convert it logically to a master/worker > multiprocess MPI that will be sended by ssh to the interpreter on the worker > side and then lunched. what about taking a step back and use PVM? Of course you have no shared memory access, but it will allow you to transfer information between nodes and start worker processes: http://www.netlib.org/pvm3/book/node17.html Looks like PVM is no longer included in Pelican_HPC by default, but you can compile it on your own. -- Reuti > This is what i've tried to explain in the last msg. A dream for the hobyist > that want to get the full power of a night-time cluster, without having to > learn all the MPI syntax and structure. > > If it doesn't exist, this would be a really great tool i think. > > Thank you for your reply, but i think i have answered my question alone... No > Pain, No Gain... > > On 20 Sep 2010, at 22:24, Mikael Lavoie wrote: > > I wanna know if it exist a implementation that permit to run a single host > > process on the master of the cluster, that will then spawn 1 process per > > -np X defined thread at the host specified in the host list. The host will > > then act as a syncronized sender/collecter of the work done. > > I don't fully understand you explanation either but I may be able to help > clear up what you are asking for: > > If you mean "pthreads" or "linux threads" then no, you cannot have different > threads on different nodes under any programming paradigm. > > However if you mean "execution threads" or in MPI parlance "ranks" then yes, > under OpenMPI each "rank" will be a separate process on one of the nodes in > the host list, as Jody says look at MPI_Comm_Spawn for this. > > Ashley, > > -- > > Ashley Pittman, Bath, UK. > > Padb - A parallel job inspection tool for cluster computing > http://padb.pittman.org.uk > > > _______________________________________________ > 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
