Re: [gentoo-dev] Setting number of parallel builds for other build-systems than 'make'

[Brian Harring]

On Sun, Oct 01, 2006 at 09:52:14AM -0700, Donnie Berkholz wrote:
> Tiziano Müller wrote:
> >-----BEGIN PGP SIGNED MESSAGE-----
> >Hash: SHA1
> >
> >Hi everyone
> >
> >It seems that setting the number of parallel builds using '-jN' does not
> >only work for make, but also for scons and bjam (and maybe others as well).
> >Since it isn't save to assume that '-jN' is the only option in MAKEOPTS,
> >some filtering is needed.
> >Now, SCONSOPTS (BJAMOPTS respectively) could be added to make.conf and used
> >whenever one of those build-systems is being used. But we would probably
> >have to add a ...OPTS for every build-system.
> >
> >What do you think? Better ideas?
>
> I think adding it for each build system is probably a good idea,
> nobody's guaranteeing option-level compatibility with make. Optionally
> falling back to using the few valid MAKEOPTS might be a nice addition.

I might be daft (likely), but why not just introduce a var indicating 
max parallelization instead?  Tweak portage to push that setting into 
MAKEOPTS="${MAKEOPTS+${MAKEOPTS} } -j${PARALLELIZATION}".

Might sound daft, but -j is hardcoded parallelization; if you're 
trying to run 3 build processes, the original var of -j isn't all that 
useful, nor will the hardcoded -j# var set for 3 package build 
processes be useful if you're doing a single build.

Depending on number of seperate package build processes possible, the 
# of build processes allocated per build process needs to vary 
(essentially).

Now... that's a bit ahead of what portage is doing atm, but folks 
*will* parallelize portage building (see bug 147516 if in doubt), so 
its not too far out.

Getting back to the actual topic, set this var, it's a raw int that a 
scons/bjam eclass can use to easily set appropriate var with the 
parallelization requested, thus unifying this particular knob; more 
importantly, it gives them a way to do what they're after while 
exposing a knob that the pkg manager can easily fiddle with for global 
parallelization needs.

Only downside to it I see is that it requires mangling the pkg manager 
to translate the parallelization setting into MAKEOPTS+=-j#; can't 
really get around that however due to the fact MAKEOPTS is already 
forced in installed configuration though.

Thoughts?
~harring