Charm++ parallel programming system

[Phil Miller <mille121 AT illinois.edu>]

Two notes:

First, charm++, the runtime system used by namd, is not related to charmm, the force field or the md package built around it. The name similarity is an unfortunate accident of history.

Second, one of my colleagues here at llnl does experimental development directly on ibverbs on lab clusters, so it's definitely doable.

> On Sep 8, 2011 10:22 AM, "Bennion, Brian" <Bennion1 AT llnl.gov> wrote:
>
>
>
>
> Hello,
>
> Compilation of all the suggested versions of charm++ have been completed.
> They were:
> mpi-linux-x86_64
> mpi-linux-x86_64 smp
> net-linux-x86_64 ivberbs
> net-linux-x86_64 ibverbs smp
>
> It appears that the first charmm build is the best for namd2.8.  I saw a 25% speedup on my regular jobs using the same processor counts.  No extra tricks were employed in compiling charm++ or namd2.8.
>
> The ibverbs version did compile for charm++ and namd2.8 and was even able to start.  however, sockets closed prematurely on some node and the whole things burns to the ground.
>
> Two quick thoughts here.  First, looking at the charm.XXXXX files that are created, they look for some /tmp/charm.XXXX directories that are not going to be available.  The tmp filesystem goes by username it /tmp/bennion1/XXXXX
>
> Second, I will check with our admins to see if using ib layer is even permissible.
>
> Brian
>
> _______________________________________________
> charm mailing list
> charm AT cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/charm
> _______________________________________________
> ppl mailing list
> ppl AT cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/ppl