Parallel builds of glibc / PARALLELMFLAGS

[Carlos O'Donell]

On 09/24/2014 12:18 PM, Steve Ellcey wrote:
> 
> I have a question about parallel builds of glibc.  Someone asked me about 
> PARALLELMFLAGS and I was trying to understand what the current situation
> is.  It looks like you need to set this to something like "-j 4" to do
> parallel builds but in manual/install.texi there is this statement that
> seems to contradict that idea:
> 
> | If you want to run a parallel make, simply pass the @samp{-j} option
> | with an appropriate numeric parameter to @code{make}.  You need a recent
> | GNU @code{make} version, though.
> 
> So, is using PARALLELMFLAGS the 'correct' way to do parallel builds (in which
> case I will submit a patch to update install.texi) or should -j flags be
> getting automatically passed down to sub-makes, in which case I think there is
> a bug in the makefiles that is preventing this and we should figure out
> how to fix it.

There is indeed a bug.

Using PARALLELMFLAGS is just a kludge that makes it work.
I've already whispered the magic incantations to Brooks
and Konstantin to get them running in parallel, and would
like not to have tell it to anyone else.

>From a first principles perspective the library should 
"just work" (tm) without needing expert guidance on how
to build it in parallel.

Please fix it :-}

Cheers,
Carlos.