Re: [Caml-list] Accelerating compilation

[Jacques-Pascal Deplaix <jp.deplaix@gmail.com>]

Personally, I'd prefer the second solution because the former will not 
do anything during the first build (if I'm not wrong) and this is quite 
problematic for end user (for installation).

On 09/07/2013 09:13 PM, Wojciech Meyer wrote:
> Xavier Leroy <Xavier.Leroy@inria.fr> writes:
>
>>> 3) Parallel compilation in Ocamlbuild
>>> Of course it would help but it is not easy to implement so I'm just
>>> putting it there to be exhaustive.
>> As others said, ocamlbuild has some support for parallelism, but
>> it's much less effective than "make -j".  One reason could be that
>> ocamlbuild discovers dependencies as it goes, so it's doing online
>> scheduling, in contrast with make's offline scheduling.  But within
>> the online scheduling approach, there is certainly room for
>> improvement.  Suggestions and patches welcome.
> That's exactly what happens and is described here:
>
>    http://caml.inria.fr/mantis/view.php?id=5754
>
> Unfortunately it's not that easy to fix. Possible solutions:
>
> - do the scheduling after the project was build for the first time and
>    then:
>    * for each of the targets note the products and store it in the
>      database
>    * when the target changes, re-build the database for this target and
>      it's products
>
> - provide simpler and less dynamic rules for ocamlbuild:
>    * that actually don't run the Caml code, but do only invoke shell
>      commands with some substitution
>    * try to convert existing rules to the static ones
>
> Both solutions guarantee perfect scheduling.
>
> Wojciech
>