[Octopus-devel] [Octopus-notify] svn commit: r3861 - trunk/src/h_sys by xavier

[Florian Lorenzen]

Hi Xavier,

I don't know if your commit already helps with that because I know too
little about the pseudo-part of the code, but the the main bottleneck
of domain paralellization is not the all-to-all communication in the
kinetic energy but the allreduce in the application of the
pseudo-potentials. For 1.2 Million inner points and calculating the
ground state of a LiH chain the allreduces are 18 % of the entire run
time and the all-to-all is just 6 %. So, if we want to improve the
scalabality, the projector code has to be rewritten, ideally just one
alreduce per Hpsi operation or, even better, just one allreduce per
block of Kohn-Sham states, but I don't know if that is possible. As
you seem to be working on that now, perhaps you want to have a look at
this issue.

Best regards,

Florian

At Mon, 10 Mar 2008 23:13:12 GMT,
octopus-notify at tddft.org wrote:
>
>       Author: xavier
>         Date: Mon Mar 10 23:13:06 2008
> New Revision: 3861
>    Changeset: http://www.tddft.org/trac/octopus/changeset/3861
>
> Modified:
>    trunk/src/h_sys/kb_projector.F90
>    trunk/src/h_sys/kb_projector_inc.F90
>    trunk/src/h_sys/projector.F90
>    trunk/src/h_sys/projector_inc.F90
>
> Log:
> Implemented a new scheme to apply pseudo potentials, for the moment is
> only for KB.
>
>
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> Octopus-notify mailing list
> Octopus-notify at tddft.org
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