Re: SMP multithreading

[Sylvain Le Gall <sylvain@le-gall.net>]

Hi,

On 15-11-2010, Wolfgang Draxinger <wdraxinger.maillist@draxit.de> wrote:
> Hi,
>
> I've just read
> http://caml.inria.fr/pub/ml-archives/caml-list/2002/11/64c14acb90cb14bedb2cacb73338fb15.en.html
> in particular this paragraph:
>| What about hyperthreading?  Well, I believe it's the last convulsive
>| movement of SMP's corpse :-)  We'll see how it goes market-wise.  At
>| any rate, the speedups announced for hyperthreading in the Pentium 4
>| are below a factor of 1.5; probably not enough to offset the overhead
>| of making the OCaml runtime system thread-safe.
>
> This reads just like the "640k ought be enough for everyone". Multicore
> systems are the standard today. Even the cheapest consumer machines
> come with at least two cores. Once can easily get 6 core machines today.
>
> Still thinking SMP was a niche and was dying?
>

Hyperthreading was never remarkable about performance or whatever and is
probably not pure SMP (emulated SMP maybe?).

> So, what're the developments regarding SMP multithreading OCaml?
>

There are various development regarding this subject (most recent
first):
- Plasma (MapReduce in OCaml)
  http://plasma.camlcity.org/plasma/index.html
- OC4MC (OCaml for MultiCore)
  http://www.algo-prog.info/ocmc/web/
- ocamlp3l
  http://camlp3l.inria.fr/eng.htm
- jocaml 
  http://jocaml.inria.fr/
- ocamlmpi
  http://forge.ocamlcore.org/projects/ocamlmpi/

All these projects try to tackle the challenge of SMP from different
point of view. Maybe you'll find what your answer in one of them.

Regards,
Sylvain Le Gall