Development statistics for 6.8
Of the developers contributing to 6.8, 245 appeared for the first time. The most active developers in this cycle were:
Most active 6.8 developers
By changesets Uwe Kleine-König 368 2.6% Kent Overstreet 317 2.2% Lucas De Marchi 189 1.3% Krzysztof Kozlowski 182 1.3% Dmitry Baryshkov 148 1.0% Matt Roper 135 0.9% Andy Shevchenko 133 0.9% Andrii Nakryiko 129 0.9% Matthew Brost 115 0.8% Matthew Wilcox 113 0.8% David Howells 108 0.7% Arnd Bergmann 104 0.7% Matthew Auld 102 0.7% Randy Dunlap 102 0.7% Jakub Kicinski 94 0.7% Neil Armstrong 90 0.6% Alexander Viro 90 0.6% Thomas Zimmermann 83 0.6% Christoph Hellwig 80 0.6% Konrad Dybcio 79 0.5%
By changed lines Arnd Bergmann 59205 7.3% Matthew Brost 46142 5.7% Jakub Kicinski 37553 4.6% Sarah Walker 29771 3.7% Neil Armstrong 21336 2.6% Rajendra Nayak 16235 2.0% Thomas Zimmermann 14881 1.8% Andrii Nakryiko 12938 1.6% Kent Overstreet 12617 1.6% Darrick J. Wong 12403 1.5% David Howells 10224 1.3% Nas Chung 10207 1.3% Ping-Ke Shih 8007 1.0% Shinas Rasheed 8006 1.0% Dmitry Safonov 7938 1.0% Lucas De Marchi 7324 0.9% Vlastimil Babka 5377 0.7% Peter Griffin 5263 0.7% Donald Robson 4911 0.6% Dmitry Baryshkov 4873 0.6%
In the changesets column, Uwe Kleine-König once again ends up on top, mostly for ongoing work refactoring platform drivers. Kent Overstreet is not far behind, though, as he works to stabilize bcachefs (and also did a bit of include-file rationalization). Lucas De Marchi worked on the new Intel Xe graphics driver, Krzysztof Kozlowski worked mostly with devicetree files, and Dmitry Baryshkov worked extensively with Qualcomm drivers.
Arnd Bergmann, as usual, worked all over the kernel tree; he landed at the top of the "changed lines" column by removing a number of old and unloved WiFi drivers. Matthew Brost did a lot of work with the Xe driver. Jakub Kicinski removed a bunch of machine-generated, netlink-related code, Sarah Walker added the PowerVR/IMG GPU driver, and Neil Armstrong added a number of Qualcomm clock-controller drivers.
The top testers and reviewers this time around were:
Test and review credits in 6.8
Tested-by Daniel Wheeler 151 14.0% Pucha Himasekhar Reddy 51 4.7% Hyeonggon Yoo 31 2.9% Fuad Tabba 23 2.1% Arnaldo Carvalho de Melo 23 2.1% Philipp Hortmann 23 2.1% David Rientjes 21 1.9% Andrew Halaney 19 1.8% Hans de Goede 16 1.5% Jeremi Piotrowski 16 1.5% Randy Dunlap 15 1.4% Neil Armstrong 14 1.3%
Reviewed-by Krzysztof Kozlowski 226 2.4% Matt Roper 214 2.3% Simon Horman 210 2.2% Konrad Dybcio 204 2.1% Christoph Hellwig 195 2.1% Matthew Brost 189 2.0% Rodrigo Vivi 176 1.9% Lucas De Marchi 167 1.8% Dmitry Baryshkov 121 1.3% AngeloGioacchino Del Regno 115 1.2% Hans de Goede 107 1.1% Jan Kara 98 1.0%
As usual, Daniel Wheeler tests many of the driver patches coming out of AMD, while Pucha Himasekhar Reddy performs a similar function within Intel. Hyeonggon Yoo, instead, has made a habit of testing memory-management patches coming from a number of developers. On the review side, Krzysztof Kozlowski reviewed large numbers of devicetree patches; Matt Roper's review was focused mostly on Xe patches. Konrad Dybcio also reviewed devicetree patches, Simon Horman worked in the networking subsystem, and Christoph Hellwig looked at a lot of block-layer patches.
Looking at Signed-off-by tags applied by developers other than the author of a patch reveals who handled the patch after it was posted; it shows who the first-level maintainers are. In 6.8, the pattern of non-author signoffs was a bit different than usual:
Non-author signoffs in 6.8
Individuals Rodrigo Vivi 955 7.1% Greg Kroah-Hartman 797 6.0% Andrew Morton 601 4.5% Jakub Kicinski 565 4.2% David S. Miller 537 4.0% Alex Deucher 500 3.7% Mark Brown 485 3.6% Bjorn Andersson 443 3.3% Alexei Starovoitov 279 2.1% Hans Verkuil 260 1.9% Kalle Valo 214 1.6% Arnaldo Carvalho de Melo 177 1.3% Martin K. Petersen 164 1.2% Paolo Abeni 153 1.1% Takashi Iwai 149 1.1% Herbert Xu 147 1.1% Shawn Guo 131 1.0% Palmer Dabbelt 130 1.0% Mauro Carvalho Chehab 128 1.0% Vinod Koul 127 0.9%
Employers Intel 2260 16.9% Red Hat 1434 10.7% Linaro 1337 10.0% 1326 9.9% Meta 1048 7.8% Linux Foundation 860 6.4% Qualcomm 740 5.5% AMD 653 4.9% SUSE 409 3.1% (Unknown) 377 2.8% (None) 278 2.1% Cisco 260 1.9% NVIDIA 249 1.9% Oracle 203 1.5% Microsoft 200 1.5% Huawei Technologies 171 1.3% IBM 150 1.1% Collabora 147 1.1% Rivos 132 1.0% (Consultant) 124 0.9%
Rodrigo Vivi is not a name that comes quickly to mind when thinking about kernel maintainers (even for those of us who think about such things). In what is getting to be a common theme, the reason for his presence at the top of this list is that he is the maintainer who manages patches for the new Xe driver. Other than that, the busiest maintainers are the usual crowd that one would expect to see on that list. The Xe work also put Intel at the top of the signoffs list — though the Xe patches account for less than half of the total handled by Intel maintainers.
As has been the case for years, over half of the patches going into the kernel pass through the hands of developers working for just five companies.
Speaking of companies, 219 companies were identified as supporting work on the 6.8 kernel; the most active of those were:
Most active 6.8 employers
By changesets Intel 2527 17.5% (Unknown) 1087 7.5% Linaro 1084 7.5% 878 6.1% Red Hat 871 6.0% (None) 757 5.3% AMD 657 4.6% Pengutronix 416 2.9% SUSE 372 2.6% Meta 368 2.6% Oracle 346 2.4% NVIDIA 266 1.8% Qualcomm 261 1.8% Huawei Technologies 237 1.6% IBM 224 1.6% Collabora 167 1.2% Broadcom 142 1.0% Arm 141 1.0% Bootlin 135 0.9% Renesas Electronics 132 0.9%
By lines changed Intel 151009 18.7% Linaro 115647 14.3% Meta 59065 7.3% (Unknown) 52084 6.4% Red Hat 43378 5.4% Imagination Technologies 34692 4.3% Qualcomm 30115 3.7% SUSE 27574 3.4% (None) 22259 2.8% 22067 2.7% AMD 21853 2.7% Oracle 19462 2.4% Realtek 12587 1.6% Marvell 10869 1.3% Bootlin 8978 1.1% MediaTek 8449 1.0% NVIDIA 8163 1.0% Arista Networks 7955 1.0% Ideas on Board 7429 0.9% ST Microelectronics 7057 0.9%
Intel dominates the by-changesets list — and would be at the top even without the Xe contribution. The 6.7 kernel showed a spike in contributions from unaffiliated developers; that number has reverted to something close to its long-term mean in 6.8, though. Otherwise, these numbers are about the same as they usually are.
Fixes
Commits fixing a bug should contain a Fixes tag identifying the commit that introduced the bug; that practice helps in the understanding of the problem and informs the backporting effort for the stable releases. In 6.8, 2,582 commits contained a total of 2732 Fixes tags identifying 2,292 commits in 90 releases. Of those tags, 533 identified other 6.8 commits, and thus do not refer to bugs that made it into a released kernel.
The distribution of the remaining tags is shown in the following table. The "Fixed" column indicates the number of commits in the named release that were fixed by commits in 6.8, while "By" gives the number of commits in 6.8 fixing that release.
Releases fixed in v6.8 Release Commits Fixed By v6.7 241 282 282 v6.6 137 164 164 v6.5 125 146 146 v6.4 84 103 103 v6.3 83 91 91 v6.2 74 82 82 v6.1 50 51 51 v6.0 70 73 73 v5.19 53 54 54 v5.18 45 45 45 v5.17 27 28 28 v5.16 43 43 43 v5.15 32 35 35 v5.14 22 26 26 v5.13 33 35 35 v5.12 27 31 31 v5.11 30 35 35 v5.10 23 26 26 v5.9 25 27 27 v5.8 26 29 29 v5.7 26 30 30 v5.6 31 34 34 v5.5 16 16 16 v5.4 15 25 25 v5.3 25 25 25 v5.2 11 11 11 v5.1 12 19 19 v5.0 11 12 12 v4.20 25 30 30 v4.19 18 21 21 v4.18 13 13 13 v4.17 11 10 10 v4.16 14 16 16 v4.15 11 11 11 v4.14 9 10 10 v4.13 5 5 5 v4.12 7 8 8 v4.11 11 11 11 v4.10 14 14 14 v4.9 7 7 7 v4.8 14 14 14 v4.7 8 9 9 v4.6 7 7 7 v4.5 4 4 4 v4.4 6 6 6 v4.3 9 9 9 v4.2 9 10 10 v4.1 6 7 7 v4.0 1 1 1 v3.19 4 9 9 v3.18 9 9 9 v3.17 7 7 7 v3.16 13 13 13 v3.15 6 6 6 v3.14 4 5 5 v3.13 3 6 6 v3.12 6 6 6 v3.11 6 6 6 v3.10 11 16 16 v3.9 4 4 4 v3.8 4 4 4 v3.7 4 4 4 v3.6 2 2 2 v3.5 4 4 4 v3.4 3 3 3 v3.3 5 6 6 v3.2 5 5 5 v3.1 3 3 3 v3.0 4 4 4 v2.6.39 6 6 6 v2.6.38 4 6 6 v2.6.37 3 3 3 v2.6.36 2 2 2 v2.6.35 2 2 2 v2.6.34 4 4 4 v2.6.33 2 2 2 v2.6.31 1 1 1 v2.6.30 3 3 3 v2.6.29 2 3 3 v2.6.28 2 2 2 v2.6.27 2 2 2 v2.6.26 2 2 2 v2.6.25 2 2 2 v2.6.23 1 1 1 v2.6.22 3 5 5 v2.6.18 1 1 1 v2.6.17 2 2 2 v2.6.13 1 1 1 v2.6.12 1 23 23
Thus, 6.8 contained 23 commits with fixes tags identifying a single commit in 2.6.12 that needed a lot of fixing; that is, of course, the initial commit made at the beginning of the Git era. It has been almost 19 years, but we're still fixing bugs that went in prior to the adoption of Git.
The pattern shown above is typical for a kernel release; while a lot of the bugs fixed were introduced within the last year, there are also vast numbers of bugs that have lurked in the kernel for far longer.
In conclusion
As a final note: the Xe driver, first merged for 6.8, figures strongly in the statistics for this cycle; it is worth looking just a bit more at this work to see what is involved in adding a new graphics driver to the kernel. The Xe driver accounted for 1,041 changesets in this development cycle. Those commits were contributed by 70 developers, 66 of whom work for Intel (with a few still sticking to their Habana Labs email addresses). Their work added about 60,000 lines of code to the kernel.
Once upon a time, such a code contribution would have been huge news;
in 2024, it draws little attention outside of the community that is
interested in graphics drivers. Such is the nature of contemporary kernel
development, where the addition of major new code components is a routine
event. As of this writing, there are over 11,600 changesets waiting
in linux-next for the 6.9 merge window to open, so it seems that the flow
will not be stopping soon; keep your eyes on LWN to see what those commits
bring.
| Index entries for this article | |
|---|---|
| Kernel | Releases/6.8 |
Posted Mar 11, 2024 21:06 UTC (Mon)
by narmstrong (subscriber, #107272)
[Link]
Posted Mar 22, 2024 4:07 UTC (Fri)
by Shabbyx (guest, #104730)
[Link]
Development statistics for 6.8
Development statistics for 6.8