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Subject: Re: [OMPI users] Shared memory
From: Andrei Fokau (andrei.fokau_at_[hidden])
Date: 2010-09-24 08:42:13


The data are read from a file and processed before calculations begin, so I
think that mapping will not work in our case.

Global Arrays look promising indeed. As I said, we need to put just a part
of data to the shared section. John, do you (or may be other users) have an
experience of working with GA?

http://www.emsl.pnl.gov/docs/global/um/build.html
*When GA runs with MPI:*

MPI_Init(..) ! start MPI
GA_Initialize() ! start global arrays
MA_Init(..) ! start memory allocator

   .... do work

GA_Terminate() ! tidy up global arrays
MPI_Finalize() ! tidy up MPI
                  ! exit program

On Fri, Sep 24, 2010 at 13:44, Reuti <reuti_at_[hidden]> wrote:

> Am 24.09.2010 um 13:26 schrieb John Hearns:
>
> > On 24 September 2010 08:46, Andrei Fokau <andrei.fokau_at_[hidden]>
> wrote:
> >> We use a C-program which consumes a lot of memory per process (up to few
> >> GB), 99% of the data being the same for each process. So for us it would
> be
> >> quite reasonable to put that part of data in a shared memory.
> >
> > http://www.emsl.pnl.gov/docs/global/
> >
> > Is this eny help? Apologies if I'm talking through my hat.
>
> I was also thinking of this when I read "data in a shared memory" (besides
> approaches like http://www.kerrighed.org/wiki/index.php/Main_Page). Wasn't
> this also one idea behind "High Performance Fortran" - running in parallel
> across nodes even without knowing that it's across nodes at all while
> programming and access all data like it's being local.
>
> -- Reuti
>
>