On 4/28/07, Eric Van Hensbergen <ericvh@gmail.com> wrote:

On 4/28/07, Lucio De Re < lucio@proxima.alt.za> wrote:
> > No, but you're not going to like the reason. AFAIK nobody misses it,
> > because there may not be a single HPC app in widespread use that could
> > be run on Plan 9 today. We've been looking. Roman knows more than I do
> > on this issue.
>
> But the question would be whether those applications do use complex
> types and thus adding them to KenCC would bring them closer to porting
> to Plan 9.  At least, that seems a legitimate question.
>

What Ron is saying is that the problem with making most HPC apps work
on Plan 9 are not C language features -- its the lack of support for
popular languages for doing HPC work.  Fortran is the 1000 lbs gorilla
here, although there are quite a few C++ codes as well.  The second
problem is the lack of support for certain libraries -- like OpenMP
and MPI -- which are heavily reliant on POSIX features that are the
least compatible with Plan 9 (posix threads, BSD sockets, signals,
mmap, etc.)

>
> Or are you saying that no HPC app comes even remotely close to being
> portable?
>

There are multiple degrees of portability.  Most of the world
considers POSIX the portability layer (and APE won't cut it on our end
for the reasons stated above).  But even then, HPC apps are large and
complex beasts -- most take a few weeks to a month to figure out how
to compile and tune even on a "standard" system.  The problem is there
is increasingly less diversity on the UNIX OS space, so the "standard"
is rapidly moving from POSIX to Linux/X11.

                 -eric