Re: singleton MPI_Init

Raja Daoud (raja@tbag.rsn.hp.com)
Mon, 24 Jun 1996 10:24:21 CDT

> Bill Saphir afterwards was that some folks thought the semantics would
> be unclear if the implementation uses a daemon:

This could be clarified by stating that implementations may auto-start
the daemon(s) in the singleton case, or may require that the daemon(s)
to be started independently. I think this is acceptable. The issue
we're hitting on here is: what is the MPI environment? Is the LAM/PVM
daemon part of it or part of MPI? I think they're not part of MPI, they
both do more than just run MPI jobs. Just as the MPI-singleton wouldn't
be required to boot UNIX, I think it's acceptable not to require it to
boot other non-MPI environments it may depend on. With this, we can
then leave it up to the implementations to decide which part they
consider "MPI environment" (and thus auto-start with the singleton) and
which parts they exclude. This doesn't just apply to LAM/PVM, it also
applies to resource managers. If it helps, just consider LAM/PVM daemons
to be "resource manager"-like.

--Raja

-=-
Raja Daoud Hewlett-Packard Co.
raja@rsn.hp.com Convex Division