I agree with this solution, for the machinefile. Using mpiexec or a spawn command, you can add the cpu number attached to the hostname : mpiexec -host [hostname]:[cpu number] -n 1 mpi_test or, for MPI_Comm_spawn : MPI_Info_set( mpi_info, "host", "[hostname]:[cpu number]" );
Cheers, Laurent. > > In the machinefile, add for each node with M cpus: > myhost@mydomain slots=N cpus_allowed=<set>, > <set> being the subset of 0..M-1 in some yours-to-decide format and > with yours-to-decide default values. > > Best Regards, > Alexander Shaposhnikov > > On Wednesday 29 November 2006 06:16, Jeff Squyres wrote: > > There is not, right now. However, this is mainly because > back when I > > implemented the processor affinity stuff in OMPI (well over a year > > ago), no one had any opinions on exactly what interface to expose to > > the use. :-) > > > > So right now there's only this lame control: > > > > http://www.open-mpi.org/faq/?category=tuning#using-paffinity > > > > I am not opposed to implementing more flexible processor affinity > > controls, but the Big Discussion over the past few months is exactly > > how to expose it to the end user. There have been several formats > > proposed (e.g., mpirun command line parameters, magic MPI > attributes, > > MCA parameters, etc.), but nothing that has been "good" and "right". > > So here's the time to chime in -- anyone have any opinions on this? > > > > On Nov 25, 2006, at 9:31 AM, shap...@isp.nsc.ru wrote: > > > Hello, > > > i cant figure out, is there a way with open-mpi to bind all > > > threads on a given node to a specified subset of CPUs. > > > For example, on a multi-socket multi-core machine, i want to use > > > only a single core on each CPU. > > > Thank You. > > > > > > Best Regards, > > > Alexander Shaposhnikov