Hi all - I just ran a small test to find out the overhead of an MPI_Recv call when no communication is occurring. It seems quite high. I noticed during my google excursions that openmpi does busy waiting. I also noticed that the option to -mca mpi_yield_when_idle seems not to help much (in fact, turning on the yield seems only to slow down the program). What is the best way to reduce this polling cost during low-communication invervals? Should I write my own recv loop that sleeps for short periods? I don't want to go write someone that is possibly already done much better in the library :)
Thanks, Brian
