Re: [Caml-list] Accelerating compilation

[Wojciech Meyer <wojciech.meyer@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 2638 bytes --]

What are you trying to prove here? Makefiles will be always faster as
mentioned before, however there is still space for vast improvement, the
biggest elephant here being slow scanning. Patches welcome.

Also, it does not show the convenience of using ocamlbuild, in particular
dynamic dependency resolver, nice language for specyfing complex rules,
tags, and VPATH build that just works (does your makefile VPATH at all?)



On Wed, Sep 11, 2013 at 2:00 PM, Francois Berenger <berenger@riken.jp>wrote:

> On 9/7/13 5:51 AM, Fabrice Le Fessant wrote:
>
>> On Fri, Sep 6, 2013 at 5:20 PM, Romain Bardou <romain.bardou@inria.fr>
>> wrote:
>>
>>> 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.
>>>>>
>>>>
>>>> I'm not sure what you are referring to, OCamlBuild does already
>>>> support parallel builds.
>>>>
>>>
>>> Does it? I actually thought the -j option was ignored.
>>>
>>> I just did a quick test and I gain about 5 seconds with -j on a 1min15
>>> build (I had cleaned, recompiled and recleaned before so that caching by
>>> the file system would not impact the result too much), so it does seem
>>> to be a *little* faster :)
>>>
>>
>> FWIW, I recently compiled Merlin with both ocamlbuild and ocp-build,
>> on a quad-core with "-j 10" for both (the link to the ocp-build
>> description file is in the latest OCamlPro's report), ocamlbuild needs
>> 13s where ocp-build only needs 4s to compile everything.
>>
>
> This morning, I played with a Makefile and ocamlbuild
> to build batteries-included from a clean source tree.
>
> The Makefile was provided by Cedric Cellier.
>
> Here follows the wallclock times to build on my eight cores machine.
>
> #You can plot them like this:
> cat <<EOF > make_Vs_ocamlbuild.data
> #nprocs Makefile ocamlbuild
> 1 14.52 21.43
> 2 6.84 17.57
> 3 4.95 16.44
> 4 4.18 15.95
> 5 3.70 15.67
> 6 3.36 15.62
> 7 3.12 15.54
> 8 3.03 15.292
> EOF
> gnuplot -persist <<EOF
> set title 'make Vs ocamlbuild'
> set xlabel 'nprocs'
> set ylabel 'wallclock time(s)'
> plot 'make_Vs_ocamlbuild.data' u 1:2 w lines title 'time -p make fast -j
> np', \
>                             '' u 1:3 w lines title 'ocamlbuild -j np'
> EOF
>
>
>
> --
> Caml-list mailing list.  Subscription management and archives:
> https://sympa.inria.fr/sympa/**arc/caml-list<https://sympa.inria.fr/sympa/arc/caml-list>
> Beginner's list: http://groups.yahoo.com/group/**ocaml_beginners<http://groups.yahoo.com/group/ocaml_beginners>
> Bug reports: http://caml.inria.fr/bin/caml-**bugs<http://caml.inria.fr/bin/caml-bugs>
>

[-- Attachment #2: Type: text/html, Size: 3889 bytes --]