Mpiexec release 0.74, blame Myricom

[Pete Wyckoff]

Changes from 0.73 only affect users of MPICH/GM, and in particular an
upgrade is necessary only if you plan to use versions >= 1.2.5..10 of
MPICH/GM from Myricom.

In particular, Myricom has released yet another new version of their
startup code with 1.2.5..10. There are now three different
initialization procedures among the various releases of MPICH/GM from
Myricom. The New and Old models, embodied in releases 1.2.5..10 and
1.2.4..8, respectively, are managed by mpiexec version 0.74 and later by
dynamically choosing which one to use depending on output from the
spawned compute processes. The third model, labelled Older below, is so
different that only old versions of mpiexec can deal with
it---preserving compatibily there was too hard.

This table maps MPICH/GM version to compatible mpiexec version.
Quick note: if you have upgraded MPICH/GM since 26 Aug 2002,
the latest mpiexec is the right choice.

            mpich-gm      mpiexec
    New     >= 1.2.5..10  >= 0.74
    Old     >= 1.2.4..8   >= 0.70
    Older   <  1.2.4..8   <= 0.69

Thanks to Christopher Maestas for discovering that Myricom changed the
way they handle process startup in recent releases of their MPICH/GM.


Full changelog and downloads at:  http://www.osc.edu/~pw/mpiexec/
Do respond to the list with bug reports, comments, suggestions,
and complaints.

		-- Pete