Project build speed importance

December 12, 2014 by
Filed under: Configuration Management, Development, Linux 

I began writing this several years ago but never published it for various reasons. I think some of the thoughts are still really interesting, I joined a company named Pelagicore some months ago and we do some rather large builds at this company, similar in build times in the project I refer to in this text, but with some major differences. This build is based on yocto and it actually works really well once you get through the first build (currently a scratch dev image build is up to 4 hours in time, but after that it’s able to rebuild only changed software and recipes as necessary. The scratch build is heavy admittedly, but we are working on some ways to improve that as well, such as sstate caches, icecc distributed build systems, and so forth. I think with modifications we could get those 4 hours down to under an hour, which would be really sweet. Anyways, I thought I’d post this text as is, even though it’s not finished, just because and since I re-read it right now 😉 .

Original text


Again, I’m struck by the importance of a proper build process in projects. No matter how small or big the project is, the build must be kept fast and working from get go to the end — which means its end of life cycle. I am currently working in a large project with a huge code base where the build system is, in my opinion, next to completely collapsed. Build time is in excess of 1-4 hours, and the automated test-suites take from 3 hours to 7 hours to complete, depending on how thorough a test-suite you choose. A gigantic heap of time is spent just…. waiting… waiting…. waiting. Just to make a simple one line edit and then compile to see if it compiles can take up to 4 hours. I’ve previously been a bit spoiled with good and simple build systems, only occasionally running into really crappy build systems — for some reason, a lot of scientific open source software seem to be stuck in this category.

This time, I think I hit pay-dirt on “how not to do it”. Instead of focusing on the bad parts, I will try to focus on the things to do and to keep in mind. Nobody seems to like a grumpy person anyways, which I really am sometimes.

1. Keep the build system simple and manageable. Try to maintain the build system in a logical fashion and in a single language/system (scons/python, Makefiles, etc).
2. Expandable (new directories, files, etc)
3. Scalable (multiple CPU’s, machines, threads, etc)
4. Try to use as few frontends as possible (a single top makefile for example, with targets depending on what you want to do), and keep people informed of changes. Wiki with history via RSS is _perfect_ for this. This doesn’t mean you can create a script to build something, then 2 months down the road delete it because it is no longer needed, it causes a lot of stress for developers who just barely had a chance to find the script.
5. The programmers are (most likely) your customers.

Comments

Tell me what you're thinking...
and oh, if you want a pic to show with your comment, go get a gravatar!