Re: [Starpu-devel] mpi_isend_detached / mpi_irecv_detached with starpu-trunk with tag

[Jean-Marie Couteyen <jean-marie.couteyen@inria.fr>]

> How long have you been using the trunk? I recently modified the engine
> to properly implement synchronous communications, it may have broken the
> tag matching system.

This week (r14553 with a patch not related to mpi), but I am just trying the 
distributed version of my application.
After your message, I tried a patched r14459 without more success.

Regards,
Jean-Marie

----- Mail original -----
> De: "Nathalie Furmento" <nathalie.furmento@labri.fr>
> À: "Jean-Marie Couteyen" <jean-marie.couteyen@inria.fr>, 
> starpu-devel@lists.gforge.inria.fr
> Envoyé: Jeudi 26 Février 2015 10:36:32
> Objet: Re: [Starpu-devel] mpi_isend_detached / mpi_irecv_detached with 
> starpu-trunk with tag
> 
> On 26/02/2015 10:08, Jean-Marie Couteyen wrote:
> > Hello,
> >
> > it seems that tag are no longer taken into account for communication
> > when calling "starpu_mpi_isend_detached" / "starpu_mpi_irecv_detached"
> > with the trunk version.
> > A magical value (_STARPU_MPI_TAG_DATA) replace the tag given when
> > StarPU calls Isend (_starpu_mpi_isend_data_func:327)
> >
> > I do rely on tags to make my communications on my application
> > (multiple isend_detached/irecv_detached identified by tags) and I
> > can't see a way to do them without it.
> > Is there a good reason to override the given tag ?
> >
> > Regards,
> > Jean-Marie Couteyen
> > _______________________________________________
> > Starpu-devel mailing list
> > Starpu-devel@lists.gforge.inria.fr
> > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/starpu-devel
> 
> The communication engine in the trunk has been completely rewritten
> compared to the 1.1 version. We found out that implementations of MPI
> were not efficient when using too many different tags.
> 
> Thus the new engine sends all data using the same tag. However the tags
> given by the application should be matched properly. It might not be
> tested though by our testcases. I will have a look.
> 

> Cheers,
> 
> Nathalie
> 
>