> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Bruce Richardson > Sent: Wednesday, June 7, 2017 11:48 AM > To: dev@dpdk.org > Cc: Richardson, Bruce <bruce.richard...@intel.com> > Subject: [dpdk-dev] [RFC PATCH] replace DPDK config and build system > > Hi all, > > following on from the pressing need to add support in DPDK for detecting > and managing external dependencies, I undertook to see what options we had. > However, unrelated to this, over time, I have become increasingly > frustrated by the complexity of the DPDK configuration and build system. As > such, I feel that looking at some of the newer build tools that are out > there might give us the additional functionality we want, along with other > benefits. As such, I undertook a prototype using "meson"[1] for > configuration, which uses "ninja" as a backend for doing the actual build. > > With these tools we get the following benefits (not a complete list): > * support for detecting dependencies on the system > * support for detecting compiler features, including functions, defines > * improved maintainability through a high-level language, which gives > decent error messages including line numbers (!!) > * co-existence with the existing makefile system without making any changes > to it > * faster builds using ninja - on my many-core system, the builds seem > significantly faster than with our existing system. Especially in the > nothing-has-changed case, builds with my prototype return instantly, > compared to taking a few seconds to recursively check each directory with > the current build system > * the ability to switch to using a standard "ninja" + "ninja install" setup > * the chance to rework our existing build-config files, and hopefully > pretty much remove them. > * pkg-config support. > * we get to move away from our bespoke build system > * dependencies in each lib can be moved back to being tracked in the libs > files themselves, not up a level > > > Of course, it's not a panacea, but having spent hours on the prototype thus > far, I find working with meson and ninja far more user-friendly than > working on our makefiles, and again the build speed is a really nice > improvment too. > > The prototype is incomplete, but it does build a reasonable number of our > libraries, some unit tests, the i40e PMD and the testpmd binary, and I have > successfully passed traffic using testpmd from the build. Some things are > not fully correct, e.g. static builds aren't working right now, as I haven't > correctly done all the dependency tracking, I think, and the cpu flag > detection has issues. It also has only been tried on x86_64 linux, on a > couple of systems, so YMMV. However, I feel it's a reasonable enough start > point to show what we might be able to achieve. > > Please take the prototype and test it out. I think it's a better > alternative to trying to bolt on additional functionality to our existing > config and build system.
Test drive done; here are my experiences / thoughts: 1) Understanding the Meson build files is much easier for me than the current build-files. I'll admit that bash scripting is not my forte, with the caveat that if my basic bash scripting doesn't suffice, others in the community are probably in a similar position. 2) I see huge value in pkg-config integration - linking made easy. From a developer usability POV, a project should provide a pkg-config file, and configure itself based on the pkg-config files available on the system. 3) The speed of ninja is impressive - particularly in the small-amounts-of-work case. Try it on your own machine if you don't believe me :) 4) "build variants" are super easy, meson build && meson build_variant will create two directories, with .o files contained under it (same as one possible usage of the current system - just calling out that that feature remains). 5) Vim users, there is a "mesonic" plugin[1] which provides syntax highlighting for Meson files, the Meson Options file, and Meson integration to the Vim compiler hooks. Aka typing :make will cause Ninja to be invoked and compile. There are more fancy features, check the script page. 6) Ninja uninstall will reverse a previous installation, and returns a clean system. Nice for testing and integrating DPDK with applications that expect DPDK to be installed system-wide. Of course no build system is perfect - and I'd guess Meson also has a few gritty details that are not ideal - but to me this test-drive has shown promise. Opinions from non-developers may be of particular interest.. @DPDK Packagers, do you have experience with Meson? Does it integrate well with (your) existing infrastructure? Hope you don't mind me adding you to CC :) -Harry [1] http://www.vim.org/scripts/script.php?script_id=5378
