openmpi

I want to run a program with mpirun on different sets of machines (All linux machines with Open Mpi 1.5). Right now I have machines where I can log on with username A , and another set of machines where I use the username B . All machines are accessible via ssh, but I can't figure out how to achieve this. My hosts file would be like this : localhost #username local machine_set_A_1 #username A machine_set_A_2 #username A ... machine_set_B_1 #username B machine_set_B_2 #username B ... Is it possible to achieve this. Thank you. The OpenSSH client supports per-host configurations, something

Usually when I use mpirun, I can "overload" it, using more processors than there acctually are on my computer. For example, on my four-core mac, I can run mpirun -np 29 python -c "print 'hey'" no problem. I'm on another machine now, which is throwing the following error: $ mpirun -np 25 python -c "print 'hey'" -------------------------------------------------------------------------- There are not enough slots available in the system to satisfy the 25 slots that were requested by the application: python Either request fewer slots for your application, or make more slots available for use. ----

I have a bit of research related question. Currently I have finished implementation of structure skeleton frame work based on MPI (specifically using openmpi 6.3 ). the frame work is supposed to be used on single machine. now, I am comparing it with other previous skeleton implementations (such as scandium , fast-flow , ..) One thing I have noticed is that the performance of my implementation is not as good as the other implementations. I think this is because, my implementation is based on MPI (thus a two sided communication that require the match of send and receive operation) while the

I wonder when do I need to use barrier? Do I need it before/after a scatter/gather for example? Or should OMPI ensure all processes have reached that point before scatter/gather-ing? Similarly, after a broadcast can I expect all processes to already receive the message? Markus Mayr All collective operations in MPI before MPI-3.0 are blocking, which means that it is safe to use all buffers passed to them after they return. In particular, this means that all data was received when one of these functions returns. (However, it does not imply that all data was sent!) So MPI_Barrier is not necessary

When I'm trying to make CUDA 5.0 samples an error appears: Makefile:79: * MPI not found, not building simpleMPI.. Stop. I've tried to download and build the latest version of Open MPI reffering to Open MPI "FAQ / Platforms / OS X / 6. How do I not use the OS X-bundled Open MPI ?" page and it did not solve the error. make -j 4 2>&1 | tee make.out [ lots of output ] make[2]: *** [mpi/man/man3/MPI_Comm_disconnect.3] Error 127 make[2]: *** Waiting for unfinished jobs.... make[1]: *** [all-recursive] Error 1 make: *** [all-recursive] Error 1 I'm realy confused for now I have no idea what to do. As