Hi: I am using openmpi-1.2.8 to run a 2 processor job on an Intel Quad-core cpu. Opsys is Debian etch. I am reaonably sure that, most of the time, one process is waiting for results from the other. The code is fortran 90, and uses mpi_send and mpi_recv. Yet "gnome-system-monitor" shows 2 cpus at 100%.
So I read, and re-read, the FAQs, and found the mpi_yield_when_idle flag, and tried it: mpirun --host localhost,localhost,localhost,localhost --mca btl sm,self --mca mpi_yield_when_idle 1 --byslot -np 2 /home/dguptill/software/sopale_nested_2008-10-24/bin/sopale_nested_openmpi-intel-noopt And still get, for each run, two cpus are at 100%. My goal is to get the system to a minimum usage state, where only one cpu is being used, if one process is waiting for results from the other. Can anyone suggest if this is possible, and if so, how? Thanks, Douglas. -- Douglas Guptill Research Assistant, LSC 4640 email: douglas.gupt...@dal.ca Oceanography Department fax: 902-494-3877 Dalhousie University Halifax, NS, B3H 4J1, Canada
