Charm++ parallel programming system

[Jim Phillips <jim AT ks.uiuc.edu>]

Try "charmrun ++mpiexec +p32 ./hello" which will use mpiexec internally to 
launch across nodes.

Jim


On Fri, 13 Feb 2015, Jozsef Bakosi wrote:

> Hi folks,
>
> I'm wondering what is the best way to run Charm++ applications on clusters
> with Infiniband interconnects. So far I've been successfully building and
> running my app using Charm++, built by the following command, which uses
> MPI:
>
> ./build AMPI mpi-linux-x86_64 mpicxx
>
> But now I'm wondering if the "ibverbs" build option provides better
> performance on Infiniband clusters. We have Qlogic and Mellanox Infiniband
> Fat-Tree interconnets. To experiment with this, I have successfully built
> Charm++ using the following command:
>
> ./build AMPI net-linux-x86_64 ibverbs
>
> But when I try to
> run net-linux-x86_64-ibverbs/tests/charm++/simplearrayhello on two compute
> nodes, I get
>
> $ ./charmrun +p32 ./hello
> Charmrun> IBVERBS version of charmrun
> mcmd: connect failed: Connection refused (32x)
> Charmrun> Error 1 returned from rsh (localhost:0)
>
> So my questions are:
>
> 1. Can I expect better performance on Infiniband clusters using build
> options other than MPI?
> 2. Do I also have to contact our system admins to allow access to lower
> (than MPI) level software layers for the interconnect so Charm++ code (I
> assume ibverbs) can use it?
> 3. Am I missing something else?
> 4. Are the best ways to build Charm++ for specific hardware documented
> somewhere?
>
> Thanks in advance, and please let me know if I you need more information on
> the clusters.
> Jozsef