Subject: CHANGES to MPI standard are damaging

From: Barry Smith <[email-masked]>
Date: Tue, 25 Jun 1996 15:28:10 -0500

As a parallel library writer (using MPI) whose software has been
downloaded, installed, and used at 100s of sites around the world, I
urge the MPI 2 participants to strongly resist the urge to make
ANY syntactical changes in the MPI 1.1 standard.

  Any change in calling sequences (no matter how trivial or well
intentioned) causes havoc for libraries. People installing libraries on
older MPI releases or older library releases on newer MPI releases
cannot build. And most do not have the time or skills to track down
the problem. Just the minor changes to the calling sequences for the
attributes in going from MPI 1.0 to 1.1 meant that the PETSc libraries
could not be installed without change and headaches. Library users
cannot tolerate having to muck around in source figuring how to update
some library due to a trivial, cosmetic change to the standard.

  MPI already has a solid base of thousands of users and one of its
great advantages over PVM is its stability. Large MPI using libraries, 10s of
thousands of lines of code, have already been written and it is not
realistic to expect those to track changes in MPI 1.? calling sequences.
It is far better to accept MPI 1.1 with its blemishes then to make any
further changes in its syntax. MPI 2.0 may add to MPI 1.1 but it should 
not change. Otherwise I fear for the future of MPI.

        Barry Smith

  A concerned MPI user and fan

---

From: "Eric Salo" <[email-masked]>
Date: Tue, 25 Jun 1996 15:10:31 -0700

Barry, is there anything specific in the current MPI-2 chapters that concerns
you? I am unaware of any proposals to change MPI-1.1 semantics, and am quite
certain that the MPI Forum would resoundingly vote down anything of the sort.

-- 
Eric Salo         Silicon Graphics Inc.             "Do you know what the
(415)933-2998     2011 N. Shoreline Blvd, 8U-808     last Xon said, just
[email-masked]      Mountain View, CA   94043-1389     before he died?"