[mpich-devel] mpi is dying?

[Jeff Hammond]

www.hammond.us/programming-model-discourse-is-dying-and-false-dichotomies-are-killing-it/

Let's look at http://on-demand.gputechconf.com/gtc/2014/webinar/gtc-express-acoates-webinar.pdf.
The author works for Baidu's Silicon Valley AI Lab.  Baidu is the
Chinese Google.  About as Silicon Valley as it gets.

Slide 30 says:

OTS HPC Sotware Infrastructure
•  Infiniband (“IB”): Use MPI
 –  MPI = Message Passing Interface
  •  Standard mid-level API usually supporing IB.

Slide 32 says "Enables message passing, but this is pretty unnatural."
 I guess Dursi is right.  MPI sucks so hard.  And it's definitely MPI
alone that uses send-recv semantics.  It's not like the Internet is
based upon that or anything.  And one definitely must switch to UPC to
get one-sided semantics.

Oh, but then - <bam> - we see on slide 33, "Hide communication inside
"distributed array".  OMG it's a high-level abstraction layer on top
of MPI that hides the supposed assembly language of parallel
programming and makes the programmer productive.

But maybe Baidu is exceptional and most HPC programmers who deal with
array are doomed to tedious MPI programming.  Let's see if there any
distributed array abstraction layers out there that hide MPI.  It took
me about 42 microseconds to find http://libelemental.org/ and
https://www.emsl.pnl.gov/docs/global/, and those are just the ones
that I have a personal relationship with.  And that is just the tip of
the MPI library iceberg.

So yeah, most people that criticize MPI do so in a manner that is
logically equivalent to "Linux is way better than Fortran".

http://arxiv.org/abs/cs/0109017 is a must-read, for anyone that hasn't already.

Jeff


On Thu, Apr 9, 2015 at 7:16 AM, Rob Latham <robl at mcs.anl.gov> wrote:
> I (and it seems quite a few others) found this yesterday:
>
> http://www.dursi.ca/hpc-is-dying-and-mpi-is-killing-it/
>
> The premise is a couple things:
> - spark, hadoop, and the "silicon valley stack" has tremendous mindshare
> - MPI is too hard for application writers
> - and too challenging for library writers
> - and HPC has "not invented here" blinders keeping it from adopting new
> techonolgy
>
> now, when someone writes "X is dying" it's more of an opening position
> statement for a discussion than a statement of fact.    But it does bother
> me immensely that there is an "HPC stack" and a "silicon valley stack".
> Convergence is happening, but not fast enough.
>
> ==rob
>
> --
> Rob Latham
> Mathematics and Computer Science Division
> Argonne National Lab, IL USA
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-- 
Jeff Hammond
jeff.science at gmail.com
http://jeffhammond.github.io/