Hi,

I have a situation when a process my start up and execute MPI_Comm_accept(), while waiting for others to join, which may take some time.

I have observed that all processes that wait in MPI_Comm_accept(), pin 1 cpu core exactly 100%.

Which is unfortunate in my situation since if i launch enough processes, i pin the entire machine node very quickly -- and it does do other things that run into a crawl.

Is this a known problem? is there a workaround for this?

I tried on ubuntu 14-04 LTS which installs mpich 3.0.4 by default but i also tested 3.2 Nov/2015 and they both exhibit this very behavior.

Thank you very much in advance.

-Dmitriy