[Buildroot] [PATCH 1/2] pkg-autotools: use --disable-dependency-tracking
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Fri Aug 29 07:21:50 UTC 2014
Dear Peter Korsgaard,
On Fri, 29 Aug 2014 09:18:15 +0200, Peter Korsgaard wrote:
> >>>>> "Thomas" == Thomas Petazzoni <thomas.petazzoni at free-electrons.com> writes:
>
> > By default, automake does "dependency tracking", which allows the
> > generated Makefile to contain the necessary dependencies to
> > automatically rebuild the appropriate C files when included header
> > files are changed. This dependency tracking is nice when doing active
> > development on the package, but not really useful when doing a
> > one-time build of the package. According to automake's
> > documentation[1], disabling the dependency tracking provides a small
> > speed-up.
>
> > In some very unscientific measurements (i.e repeated only once), we
> > have noticed a ~3.6% reduction of the total build time of a Buildroot
> > toolchain after applying this patch.
>
> > [1] http://www.gnu.org/software/automake/manual/html_node/Dependency-Tracking.html
>
> 3% isn't much, but OK - Committed both to next, thanks.
Well, I was indeed a bit disappointed by the small difference. But I
believe it anyway makes more sense than having a few random packages
pass --disable-dependency-tracking.
Also, as we say in French, "les petits ruisseaux font les grandes
rivières", which could roughly be translated as "the small streams make
the big rivers". Everything counts :-)
Thomas
--
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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