On Nov 30, 2005, at 11:47 AM, Leslie Watter wrote:
> I'm trying to create a new SSI RPI transport protocol inside LAM-MPI.
> I have a new implementation on the LLC protocol in Linux, and want to
> compare both, LLC and TCP/IP performance.
>
> Anyone can give me the guidelines to make this new "port" ?
There is a basic design document for writing a new RPI component
available at:
http://www.lam-mpi.org/using/docs/
In particular, you should probably start with the "The System
Services Interface to LAM/MPI" document for an overview of our
component system. The entire RPI interface is documented in "Request
Progression Interface (RPI) System Services Interface (SSI) Modules
for LAM/MPI". The TCP RPI is pretty complex code - some friends of
LAM put together a very nice document on it's inner workings that is
also linked from the documentation page. That should get you started
working with LAM/MPI's transport engine.
You might want to take a look at Open MPI instead of LAM/MPI. Open
MPI is the successor to LAM/MPI, developed by the LAM/MPI, FT-MPI, LA-
MPI, and PAC-X MPI development teams. It has many of the great
features of LAM/MPI (the component system, run-time selectable device
support, etc.), as well as a bunch of new features (real multi-device
support, better performance, good datatype support, etc.). The
communication architecture is slightly different - there are two
component layers under the MPI interface - the PML, which handles MPI
semantics, message fragmenting, etc. and the BTL, which handles
moving packets of data (and not much else).
For your research, you would have to implement a BTL using the LLC
protocol, which could then be compared to the TCP BTL. The BTL
interface is quite small - only 11 functions (3 of which are optional
to implement). Unfortunately, there is not as much documentation
available for the BTL interface as there is for LAM's RPI interface.
However, I think you will find the reduction in complication more
than offsets the lack of documentation.
If you are interested in using Open MPI, I'd suggest looking at some
of the papers available here:
http://www.open-mpi.org/papers/
Note that references to the TEG PML are out of date - we've
redesigned the lower layers and no longer actively support the TEG
PML. (instead using the OB1 PML and the BTL interface). If you have
any questions, there is a very responsive mailing list available -
I'd recommend subscribing to the devel mailing list - more
information is found here:
http://www.open-mpi.org/community/lists/
Hope this helps,
Brian
--
Brian Barrett
LAM/MPI developer and all around nice guy
Have a LAM/MPI day: http://www.lam-mpi.org/
|
