Re: [9fans] speaking of kenc - Plan9

This is a discussion on Re: [9fans] speaking of kenc - Plan9 ; On 4/28/07, Lucio De Re 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 ...

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Thread: Re: [9fans] speaking of kenc

  1. Re: [9fans] speaking of kenc

    On 4/28/07, Lucio De Re 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

  2. Re: [9fans] speaking of kenc

    > Fortran is the 1000 lbs gorilla
    I've often been curious about this. I did some F90 programming, & it wasn't
    too bad, but with F77, I could just feel the dust creeping in around the
    keyboard (python gives me the same feeling with all those spaces). Is the
    Fortran that's used in HPC something more modern like F95/03 (or even F--)?

    The rest of the letter is great; I was going to write a response, but your's
    hit every point I was going to make better.

    On 4/28/07, Eric Van Hensbergen wrote:
    >
    > On 4/28/07, Lucio De Re 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
    >




    --
    "No stranger to me is this wanderer: many years ago passed he by.
    Zarathustra he was called; but he hath altered.
    Then thou carriedst thine ashes into the mountains: wilt thou now
    carry thy fire into the valleys? Fearest thou not the incendiary's
    doom?
    Yea, I recognize Zarathustra. Pure is his eye, and no loathing
    lurketh about his mouth. Goeth he not along like a dancer?"
    -- The Saint, Also Sprach Zarathustra


  3. Re: [9fans] speaking of kenc

    On Sat, 2007-04-28 at 08:48 -0500, Eric Van Hensbergen wrote:
    > > 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.


    Being part of Sun's HPC community I've come to the conclusion that
    HPC market is really unique and different from the corporate/enteprise
    market in a couple of key areas. The HPC guys seem to be much more
    about in-house software development than enterprise guys. And this
    actually means that if you can offer them a real differentiator
    (even at the level of new programming languages) you have way better
    chance of winning them over than you would have with an enterprise
    account.

    I also see that computing in general is now on the brink of a new
    era where we would have to start exploiting parallelism and adapt
    our languages and models for that. And no, exploiting parallelism
    doesn't mean better OpenMP or better MPI. It means rethinking the
    way we do computing. And that, IMHO, means that Plan9 might just
    have another chance of entering mainstream computing. Mark my words,
    in 5-7 years -- POSIX threads and MPI are going to be as important
    as punch cards and COBOL are now.

    Just my 2c.

    Thanks,
    Roman.


  4. Re: [9fans] speaking of kenc

    On 4/28/07, Roman Shaposhnik wrote:

    > I also see that computing in general is now on the brink of a new
    > era where we would have to start exploiting parallelism and adapt
    > our languages and models for that. And no, exploiting parallelism
    > doesn't mean better OpenMP or better MPI. It means rethinking the
    > way we do computing. And that, IMHO, means that Plan9 might just
    > have another chance of entering mainstream computing. Mark my words,
    > in 5-7 years -- POSIX threads and MPI are going to be as important
    > as punch cards and COBOL are now.


    I'd like to hope this is true. I wish I had not been hearing this
    prediction for 10 years :-)

    True story: I once had a chance to speed up someone's runtime by a
    factor of 50, yes 50, and all they had to do was change one line in a
    shell script -- actually, one COMMAND in one LINE. No good -- I had to
    do it myself. HPC can be a frustrating business.

    But, let's hope it's true that we get to get rid of our old software
    baggage. I think it is criminal that people can get away with calling
    MPI a "programming model".

    Roman, let's plan to get together at a bar in 8 years -- 2015 -- and
    drink a toast to the demise of MPI, OpenMP, POSIX threads, and all the
    crazy stuff we do now :-)

    Actually, not a bar: I'll host the party at my house I just bought :-)

    BTW, just to whet appetites here -- assuming Usenix accepts our
    poster, we're going to have a pretty cool "Plan 9 and HPC" display at
    Usenix. You heard it here first. Hmm, I think I just joined the
    marketing dept.

    ron

  5. Re: [9fans] speaking of kenc

    For what its worth, my own brushes with HPC over the years have been
    Weather simulations written it C++ and MPI, tens of Mb of F77 Finite
    element alanysis run on mainframes (this occured twice), and video processing
    software consisting of tools connected by pipes - though nearly all the tools
    ran single threaded so parallelsim stops at the length of the pipe, say
    20 modules.

    Unfortunately none of these would have been applicable to plan9.

    I still live in hope though.

    -Steve

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