From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Fri, 29 Aug 2014 09:21:50 +0200 Subject: [Buildroot] [PATCH 1/2] pkg-autotools: use --disable-dependency-tracking In-Reply-To: <87tx4vrcg8.fsf@dell.be.48ers.dk> References: <1409259825-619-1-git-send-email-thomas.petazzoni@free-electrons.com> <87tx4vrcg8.fsf@dell.be.48ers.dk> Message-ID: <20140829092150.04986069@free-electrons.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Dear Peter Korsgaard, On Fri, 29 Aug 2014 09:18:15 +0200, Peter Korsgaard wrote: > >>>>> "Thomas" == Thomas Petazzoni 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 rivi?res", 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