Statistics from the 4.7 development cycle
The 4.7 development cycle saw the merging of 12,283 changesets from 1,582 developers; 232 of those developers appeared in the kernel changelog for the first time. Those changes added just under 300,000 lines to the kernel source and 740 new files to the kernel tree. Of those developers, the most active were:
Most active 4.7 developers
By changesets H Hartley Sweeten 208 1.7% Boris Brezillon 132 1.1% Al Viro 127 1.0% Linus Walleij 121 1.0% Geert Uytterhoeven 120 1.0% Arnaldo Carvalho de Melo 110 0.9% Ville Syrjälä 105 0.9% Laxman Dewangan 101 0.8% Arnd Bergmann 97 0.8% Jes Sorensen 97 0.8% Eric Dumazet 91 0.7% Dan Carpenter 88 0.7% Aneesh Kumar K.V 79 0.6% Michal Hocko 74 0.6% Chris Wilson 71 0.6% Wolfram Sang 68 0.6% Florian Westphal 66 0.5% James Hogan 66 0.5% Daniel Vetter 64 0.5% Imre Deak 62 0.5%
By changed lines Alex Deucher 37185 6.4% Rex Zhu 19912 3.4% Paul E. McKenney 14004 2.4% Thierry Reding 9170 1.6% Jinshan Xiong 8828 1.5% Yuval Mintz 8419 1.4% Jes Sorensen 6982 1.2% Chanwoo Choi 5742 1.0% H Hartley Sweeten 5705 1.0% Varun Prakash 5703 1.0% Boris Brezillon 5347 0.9% Aneesh Kumar K.V 5230 0.9% Tom Zanussi 5116 0.9% CK Hu 5072 0.9% Ilya Dryomov 4764 0.8% Linus Walleij 4738 0.8% Maxime Ripard 4631 0.8% Mathieu Poirier 4559 0.8% Christoph Hellwig 4232 0.7% Finn Thain 4024 0.7%
By this point it should come as no surprise that H Hartley Sweeten made it to the top of the "by changesets" list with continued work on the Comedi drivers in the staging tree; nearly 8,400 patches have gone into that subsystem since it was merged. Boris Brezillon's work was mostly focused on the memory-technology devices subsystem (and NAND controllers in particular), Al Viro made a number of fundamental changes (including parallel lookups) to the virtual filesystem layer and followed the implications of those changes through many filesystems, Linus Walleij has been reworking the GPIO subsystem, and Geert Uytterhoeven worked all over the tree, with an emphasis on various ARM-related subsystems.
In the "lines changed" column, Alex Deucher continues to work on the massive amdgpu graphics driver; Rex Zhu is also working primarily on that driver. Paul McKenney works with the read-copy-update subsystem, of course; the elevated line count this time around results from some large documentation changes. Thierry Reding works with the NVIDIA Tegra ARM subarchitecture, and Jinshan Xiong made some extensive changes to the Lustre filesystem in the staging tree.
Often work in the staging tree tends to overshadow everything else when it comes to these lists, but, this time around, only two developers who appear in the top ten on either side were working on staging code.
There were 222 companies (that we know about) that supported work merged in the 4.7 development cycle — a fairly average figure for recent years. The most active companies this time around were:
Most active 4.7 employers
By changesets Intel 1786 14.5% (None) 968 7.9% Red Hat 967 7.9% (Unknown) 861 7.0% Linaro 633 5.2% SUSE 470 3.8% IBM 378 3.1% AMD 302 2.5% Samsung 276 2.2% 244 2.0% Renesas Electronics 244 2.0% NVIDIA 231 1.9% Mellanox 227 1.8% Free Electrons 222 1.8% ARM 217 1.8% Vision Engraving Systems 208 1.7% Oracle 200 1.6% Imagination Technologies 193 1.6% Texas Instruments 185 1.5% Broadcom 141 1.1%
By lines changed Intel 86056 14.8% AMD 69065 11.8% (None) 35035 6.0% Red Hat 33887 5.8% IBM 28102 4.8% Linaro 23396 4.0% (Unknown) 23287 4.0% NVIDIA 18023 3.1% Mellanox 14011 2.4% Samsung 12918 2.2% SUSE 12810 2.2% Free Electrons 12637 2.2% QLogic 11731 2.0% ARM 9000 1.5% Rockchip 8938 1.5% Renesas Electronics 8734 1.5% Texas Instruments 7462 1.3% (Consultant) 6964 1.2% Chelsio 6868 1.2% Broadcom 6564 1.1%
This table looks as it has for some time, no real surprises here. The percentage of changes from developers working on their own time, at 7.9%, is up from 4.6, but still remains low by historical standards. Once upon a time, volunteer developers were our primary source of new contributors to the kernel. In 4.7, of the 232 first-time contributors, 132 were known to be employed at the time, 38 were known to be working on their own time, and 62 are in the "unknown" column. Even if all the unknowns are volunteers (most of them probably are), we still have more new contributors arriving via companies.
Contributing to the kernel used to be a fairly reliable way to get a job, and it probably still is. But, in 2016, it seems that many of our new developers get the job first, and it is the job that brings them to the kernel community.
The table above shows the changes contributed by the most active companies. One last question one might ask is: how many developers does each company have working on Linux? For the 4.7 development cycle, the answer looks like this:
# of developers/company Company Count Percent (Unknown) 238 14.5% Intel 198 12.1% (None) 172 10.5% Red Hat 91 5.6% IBM 64 3.9% 48 2.9% Linaro 43 2.6% Mellanox 38 2.3% SUSE 37 2.3% AMD 30 1.8% Samsung 27 1.6% Huawei Technologies 27 1.6% ARM 25 1.5% Texas Instruments 23 1.4% Broadcom 22 1.3% Oracle 21 1.3% NXP 20 1.2% Qualcomm 17 1.0% MediaTek 13 0.8% Imagination Technologies 12 0.7% Renesas Electronics 12 0.7% 11 0.7% NVIDIA 11 0.7% Code Aurora Forum 10 0.6% (Consultant) 10 0.6% Rockchip 10 0.6% Canonical 10 0.6% Free Electrons 9 0.5% Pengutronix 9 0.5% Synopsys 8 0.5%
Intel, it seems, has far more developers working on the kernel than any other company — nearly 12% of the total in 4.7. Volunteer developers may not contribute a lot of code, but there are quite a few of them; given that many (if not most) of the unknown developers probably fall into this category, developers working on their own time are still the biggest group.
The kernel community as a whole is a big group indeed, and it continues to
produce kernels in a disciplined and predictable way. The relative lack of
surprises may make for relatively boring statistics articles, but it is
certainly welcome to users of the kernel.
| Index entries for this article | |
|---|---|
| Kernel | Releases/4.7 |
