[Beowulf] cluster softwares supporting parallel CFD computing
hahn at physics.mcmaster.ca
Sat Sep 9 07:40:34 PDT 2006
> overlapped. Alas, people use blocking calls in general because they are lazy
> (50%), they don't know (40%) or they don't care (10%). There is also the
> chicken and egg problem: nobody really tried to overlap, so MPI
> implementations didn't bother to support it, so you could not really overlap,
> so nobody really tried. However, some MPI implementations can overlap today
> and some applications can leverage it.
all these points are accurate to some degree, but give a sad impression
of the typical MPI programmer. how many MPI programmers are professionals,
rather than profs or grad students just trying to finish a calculation?
I don't know, since I only see the academic side.
for academics, time-to-publish is the main criterion, which doesn't
necessarily mean well-designed or tuned code. taking a significant
piece of code and experimenting with ways of using async messaging
(or 1-sided, for that matter) is a significant investment of time,
with no obvious promise of a payback. yes, one might joke about grad
student time being free, the expertise might not also be there.
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