Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: Re: [OMPI users] Mimicking timeout for MPI_Wait
From: Douglas Guptill (douglas.guptill_at_[hidden])
Date: 2009-12-06 08:52:51

On Sun, Dec 06, 2009 at 02:29:01PM +0200, Katz, Jacob wrote:

> Thanks.
> Yes, I meant in the question that I was looking for something creative, both fast responding and not using 100% CPU all the time.
> I guess I’m not the first one to face this question. Have anyone done anything “better” than the simple solution?

My MPI application is a two-process thing, in which data is thrown
back and forth. For the most part, one process is calculating, and
the other is waiting.

I got tired of seeing both cpus at 100% load, and based on suggestions
from Jeff Squyres and Eugene Loh, wrote MPI_Recv.c and MPI_Send.c. I
load these with my application, and bingo! Only one cpu busy at any
given time.

They use a graduated sleep; the first sleep is short, the second is
twice as long, and so on, up to a maximum sleep time.

I sent the code along with my last message on the subject (December
2008, or later) so it should be in the archives. Failing that, I
could post it again, if anyone wants it.