Re: [petsc-dev] thread communicator

[Falgout, Rob]

Thanks, Barry and Jeff!  I will pass the word on about MPI-4.  I was at the 
last FASTMath meeting and I do recall that you were at least wondering whether 
a shared memory model was needed, but I didn’t realize that you had ripped all 
of the threading code out of PETSc.  For what it’s worth, I am on board with 
you about the all “MPI” model.  I don’t see a compelling reason that MPI+X is 
needed (especially if you allow for MPI to evolve into “MPI”), but since we 
already support MPI+X in hypre, it’s not a huge deal for us to continue along 
that path with everybody else.

Thanks again.

-Rob

From: Jeff Hammond [mailto:jeff.scie...@gmail.com]
Sent: Tuesday, January 12, 2016 12:36 PM
To: Barry Smith
Cc: Falgout, Rob; Yang, Ulrike Meier; PETSc
Subject: Re: [petsc-dev] thread communicator

Rob:

You might be interested in the MPI-4 endpoints proposal.  It should allow MPI 
communicators to act as thread communicators.

Jeff

On Tue, Jan 12, 2016 at 12:33 PM, Barry Smith 
mailto:bsm...@mcs.anl.gov>> wrote:

  Rob,

I guess you missed the last FASTMath meeting. We have stopped all work on 
using threads a long time ago because we never saw an improvement in 
performance and it was a pain to maintain. We even ripped the thread code out 
of PETSc so currently we are back to being an all "MPI" model.

   Barry

So far we haven't lost all our funding :-)



> On Jan 11, 2016, at 12:28 PM, Falgout, Rob 
> mailto:falgo...@llnl.gov>> wrote:
>
> Hi Barry,
>
> What is the latest on the thread communicator idea you guys were working on?  
> We are having discussions here with a variety of folks (application and 
> library developers as well as vendors) about similar ideas, so I’d like to 
> bring your work into the mix.  Let me know.  Thanks!
>
> -Rob
>
> Robert D. Falgout
> Center for Applied Scientific Computing
> Lawrence Livermore National Laboratory
> P.O. Box 808, L-561, Livermore, CA  94551
> Phone - (925) 422-4377, Email - rfalg...@llnl.gov, 
> Web - http://people.llnl.gov/falgout2



--
Jeff Hammond
jeff.scie...@gmail.com
http://jeffhammond.github.io/

Re: [petsc-dev] thread communicator

[Barry Smith]

  Rob,

I guess you missed the last FASTMath meeting. We have stopped all work on 
using threads a long time ago because we never saw an improvement in 
performance and it was a pain to maintain. We even ripped the thread code out 
of PETSc so currently we are back to being an all "MPI" model.

   Barry

So far we haven't lost all our funding :-)


 
> On Jan 11, 2016, at 12:28 PM, Falgout, Rob  wrote:
> 
> Hi Barry,
>  
> What is the latest on the thread communicator idea you guys were working on?  
> We are having discussions here with a variety of folks (application and 
> library developers as well as vendors) about similar ideas, so I’d like to 
> bring your work into the mix.  Let me know.  Thanks!
>  
> -Rob
>  
> Robert D. Falgout
> Center for Applied Scientific Computing
> Lawrence Livermore National Laboratory
> P.O. Box 808, L-561, Livermore, CA  94551
> Phone - (925) 422-4377, Email - rfalg...@llnl.gov, Web - 
> http://people.llnl.gov/falgout2

Re: [petsc-dev] thread communicator

[Jeff Hammond]

Rob:

You might be interested in the MPI-4 endpoints proposal.  It should allow
MPI communicators to act as thread communicators.

Jeff

On Tue, Jan 12, 2016 at 12:33 PM, Barry Smith  wrote:

>
>   Rob,
>
> I guess you missed the last FASTMath meeting. We have stopped all work
> on using threads a long time ago because we never saw an improvement in
> performance and it was a pain to maintain. We even ripped the thread code
> out of PETSc so currently we are back to being an all "MPI" model.
>
>Barry
>
> So far we haven't lost all our funding :-)
>
>
>
> > On Jan 11, 2016, at 12:28 PM, Falgout, Rob  wrote:
> >
> > Hi Barry,
> >
> > What is the latest on the thread communicator idea you guys were working
> on?  We are having discussions here with a variety of folks (application
> and library developers as well as vendors) about similar ideas, so I’d like
> to bring your work into the mix.  Let me know.  Thanks!
> >
> > -Rob
> >
> > Robert D. Falgout
> > Center for Applied Scientific Computing
> > Lawrence Livermore National Laboratory
> > P.O. Box 808, L-561, Livermore, CA  94551
> > Phone - (925) 422-4377, Email - rfalg...@llnl.gov, Web -
> http://people.llnl.gov/falgout2
>
>


-- 
Jeff Hammond
jeff.scie...@gmail.com
http://jeffhammond.github.io/