Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Development mailing list

Subject: Re: [OMPI devel] Threading
From: Ralph Castain (rhc_at_[hidden])
Date: 2010-10-12 11:00:50


Hmmm...I don't understand what you just said, but it definitely sounds -ugly-! :-)

I'll take your word for it - we may have to provide a lower performance version for such oddball purposes, and offer a higher capability version for everyone else. I'll see if I can keep a single version, though, assuming the code doesn't get too convoluted so as to become unmaintainable.

Otherwise, I'll branch it and "freeze" a non-threaded version for the unusual case.

Thanks!

On Oct 12, 2010, at 8:51 AM, Kenneth Lloyd wrote:

> In certain hybrid, heterogeneous HPC configurations, mpirun often cannot or
> should not be threaded through the OS under which OpenMPI runs. The primary
> OS and MPI can configure management nodes and topologies (even other MPI
> layers) that subsequently spawn various OSes and other lightweight kernels.
> These share memory spaces and indirectly access the program stacks in
> various devices.
>
> In short, yes, there are environments where this would cause a problem.
>
> ==================
> Kenneth A. Lloyd
> Watt Systems Technologies Inc.
>
>
> -----Original Message-----
> From: devel-bounces_at_[hidden] [mailto:devel-bounces_at_[hidden]] On
> Behalf Of Barrett, Brian W
> Sent: Tuesday, October 12, 2010 8:24 AM
> To: Open MPI Developers
> Subject: Re: [OMPI devel] Threading
>
> On Oct 11, 2010, at 11:41 PM, Ralph Castain wrote:
>
>> Does anyone know of a reason why mpirun can -not- be threaded, assuming
> that all threads block and do not continuously chew cpu? Is there an
> environment where this would cause a problem?
>
> We don't have any machines at Sandia where I could see this being a problem.
>
> Brian
>
> --
> Brian W. Barrett
> Dept. 1423: Scalable System Software
> Sandia National Laboratories
>
>
>
>
>
> _______________________________________________
> devel mailing list
> devel_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/devel
>
> _______________________________________________
> devel mailing list
> devel_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/devel