Subject: the gathering

From: Tony Skjellum <[email-masked]>
Date: Fri, 2 Apr 93 00:50:53 CST

Dear Context sub-committee members (and observers from collcomm, etc),

	The meeting this week underscored the need for convergence
to a unifying proposal that captures the features of Proposal I, VIII, and
III+VII=X.  The following work will be accomplished before May 12 to
that end, while respecting the current separateness of I and VIII.  I
regret having to leave current MPI meeting early, but the context
discussions were quite sufficient to put me in a higher gear on the
problems before us...

	.  Rik Littlefield agrees to organize a set of test cases to be coded
		for each proposal; proposers including codings in their
		proposals.  Deadline for such examples is April 21, 8pm EST.
		This will be discussed on mpi-context over next three weeks.
	.  I will develop a unified proposal X (with sensible names, and
		rationale, details, performance discussion, and examples). 
	.  I will ask for help, as needed, from Lyndon/Mark/Marc etc, on
		understanding nuances of their proposals,
	.  Marc Snir / Lyndon Clarke 
		will discuss changes/enhancements (if any) to Proposal I
	.  Mark Sears will complete (presumably) a full proposal VIII

(Tacit in this discussion is the accepted merger of III+VII as X,
despite its incomplete state, so we have eliminated some proposals
from consideration this round).  To be considered for a straw vote
(before next meeting), all proposals must be complete in that they
must

	.  Address their interactions with the first-reading of pt2pt, and
		current status of collcomm, including needed changes if any

	.  Provide specific syntax/semantics, as needed for pt2pt & collcomm
		chapters

	.  Describe any known flaws in syntax / semantics

	.  Describe logical subsets, if any, for MPI1

	.  Implement the examples that Rik organizes, and upon which we
		agree together (including those from Wednesday night 
		 discussion session)

	.  Include discussions of how starting works, and what the spawning
	   semantics must provide them (or through an initial message)
	   so that they can work. 

	.  The meaning of the MPI_ALL group in the proposal, if any, or
	   weaker substitutes for same.

	.  The existence/non-existence/requirement for servers or
	   shared-memory locations to effect some features

	.  Include expectations for performance of key operations
	   (eg, how much does it cost to get a new context?, can this
		be done outside of loops and cached?)

	.  Describe their use of a "cacheing facility," if any

	.  Describe their syntax/semantics of a "cacheing facility"

	.  Describe their reliance on any other MPI1 features not specifically
		part of context/group/tag/pid nature

		-	-	-	-	-

Presumably Proposals I, VIII, and X will fill all requirements to
reach the next straw poll deadline.  Whichever do make this Straw poll
deadline, (May 10, 1993, 5pm EST), can be considered by the voting
subcommittee.  A ranking will be developed, with the bottom N-2
proposals dropped.  We will meet on the evening of Wednesday, May 12,
8:00pm CST, for as long as it takes to choose the final proposal,
possibly by further merger of the remaining strong proposals.  On
Thursday, May 13, we will present our first reading of the Context
subcommittee (with possible spill over to Friday, May 14).  Actual
context sub-committee members will vote, only, in all cases.  Please
recall the two-sub-committee voting limit of the MPIF (as well as
sub-committee membership; observers are always welcome).

I will strive not to send fine-grain changes to proposal X's around,
but will wait to circulate my product in complete form, prior to May
10, so there is a lower e-mail burden for next weeks; perhaps others
will like to keep their updates coarse grain, but share important
things with everyone, for sure.  If agreements/compromises occur
between proposals and/or proposers, please share this with me and the
sub-committee in a timely fashion; I do not desire surprises at the
next meeting.  For instance, if Marc Snir were willing to consider a
separate context feature (separate from group) in Proposal I, a lot of
effort could be averted, because his proposal is pretty good otherwise
(except in re inter-group issues).  I think Lyndon will be talking to
Marc about making inter-group communication easier in Proposal I,
also.  If any breakthroughs are made, please let me know.

- Tony

PS Please copy mpi-collcomm on context-related matters for the
duration of MPIF. 

.	.	.	.	.	.	.	.	.      .
"There is no lifeguard at the gene pool." - C. H. Baldwin
"In the end ... there can be only one." - Ramirez (Sean Connery) in <Highlander>

Anthony Skjellum, MSU/ERC, (601)325-8435; FAX: 325-8997; [email-masked]

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From: Tony Skjellum <[email-masked]>
Date: Mon, 12 Apr 93 16:52:04 CDT

Mark,

You should explain what your model implies about the starting of
processes.  If you assume that processes have been started by MPI, that
is OK (generally a tacit assumption of MPI1), but in any event you
should tell us what the process is told at the moment of spawning (eg,
about ALL groups, or its name, etc), that will help it become part of
MPI-based communication.  We need to see how "safe"/"unsafe" it will
be to start MPI in every model.  If it is extremely difficult/simple
to get from the "just-spawned" state to the "MPI-up-and-running" sate,
that should be made clear.

I am happy to answer more questions!  Please shoot away.

- Tony
PS Because this is of general interest to all readers, I am echoing to
	the reflector.  I hope that is OK with you.

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From: [email-masked]
Date: Mon, 12 Apr 93 14:10:36 MST

Tony, I need a little clarification of what you mean by

"Include discussion of how starting works and what the spawning
semantics must provide them (or through an initial message)
so that they can work."

Starting and spawning what?

mark

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