You should look at these two FAQ entries: http://www.open-mpi.org/faq/?category=running#oversubscribing http://www.open-mpi.org/faq/?category=running#force-aggressive-degraded
To get what you want, you need to force Open MPI to yield the processor rather than be aggressively waiting for a message. On 10/23/07, Murat Knecht <murat.kne...@student.hpi.uni-potsdam.de> wrote: > Hi, > Testing a distributed system locally, I couldn't help but notice that a > blocking MPI_Recv causes 100% CPU load. I deactivated (at both compile- > and run-time) the shared memory bt-layer, and specified "tcp, self" to > be used. Still one core busy. Even on a distributed system I intend to > perform work, while waiting for incoming requests. For this purpose > having one core busy waiting for requests is uncomfortable to say the > least. Does OpenMPI not use some blocking system call to a tcp port > internally? Since i deactivated the understandably costly shared-memory > waits, this seems weird to me. > Someone has an explanation or even better a fix / workaround / solution ? > thanks, > Murat > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users > -- Tim Mattox, Ph.D. - http://homepage.mac.com/tmattox/ tmat...@gmail.com || timat...@open-mpi.org I'm a bright... http://www.the-brights.net/
