From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Fri, 7 Feb 2014 16:29:34 +0100 Subject: [Buildroot] Antw: build speedup possible? In-Reply-To: References: <52F49E9D.2020506@andin.de> <52F4AEC7020000460004A4EE@gwia2.rz.hs-offenburg.de> Message-ID: <20140207162934.01acfe5a@skate> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Dear Fabio Porcedda, On Fri, 7 Feb 2014 15:48:35 +0100, Fabio Porcedda wrote: > The build can be reproduced even when building packages in parallel, > we just need to record the order of the steps and replay that order if > needed. And in practice, how do you achieve this? When building in parallel, how do you record the fact that the test for libfoo in package A configure script was run before or after the installation of libfoo in the global sysroot? It's not only about recording the order of the build of the package: it's knowing whether each specific test of a configure script was run before or after the corresponding library was installed in the global sysroot. > The sysroot copy is needed only to be sure that even if some package > has an unspecified optional dependency it generates every time the > same binary. Which is *the* very important thing. So saying it's needed "only to be sure" is quite minimizing the very important consequence of parallel build with a global sysroot, IMO. > I think that at least when doing development it will be useful to > build packages in parallel. > Maybe it will be best to avoid building packages in parallel just for releases. I don't agree. I do a lot of support on #buildroot, and I would *hate* to have people coming up with bug reports that are not reproducible because they depend on the specific scheduling of the build. I really don't want new comers to use this feature and then come back with bug reports that are basically unfixable because they cannot be reproduced. I think we should really not minimize the support problem that parallelization without per-package sysroot is going to cause. Best regards, Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com