Who wrote 3.5
LWN.net needs you! Without subscribers, LWN would simply not exist. Please consider signing up for a subscription and helping to keep LWN publishing |
Now that the 3.5 Linux kernel has been released, it's time for the traditional look at who wrote it. Here we'll try to summarize who did all of the work that went into this release.
Fastest-changing kernel ever
The 3.5 kernel was released one day faster than the 3.4 kernel was, in 62 days. The last time a kernel was released this quickly was back in 2005 with the 2.6.14 kernel release (61 days).
In those 62 days, the kernel developers crammed in a record-breaking 176.73 changes per day (7.36 changes per hour.) This is the fastest-changing kernel that has been recorded since I started keeping track of this development metric back in the 2.5 kernel release series.
These changes resulted in the following overall changes:
Changes in 3.5 571987 lines added 358836 lines removed 135848 lines modified
The kernel is still increasing at a pretty constant 1.37% growth in the number of lines and files, which is similar to the growth rate of the past three kernel releases.
Individual contributions
1,195 different developers contributing patches to the 3.5 kernel; those developers worked for at least 194 different companies. The names of the contributing developers are pretty familiar to those who track these statistics:
Most active 3.5 developers
By changesets Greg Kroah-Hartman 239 2.2% Axel Lin 191 1.7% Mark Brown 187 1.7% H. Hartley Sweeten 135 1.2% David S. Miller 131 1.2% Daniel Vetter 130 1.2% Al Viro 128 1.2% Stephen Warren 121 1.1% Tejun Heo 112 1.0% Eric Dumazet 105 1.0% Hans Verkuil 102 0.9% Paul Mundt 102 0.9% Johannes Berg 102 0.9% Shawn Guo 102 0.9% Thomas Gleixner 98 0.9% Dan Carpenter 86 0.8% Sam Ravnborg 84 0.8% Chris Wilson 79 0.7% Trond Myklebust 74 0.7% Eric W. Biederman 73 0.7% Jiri Slaby 73 0.7% Arnaldo Carvalho de Melo 71 0.6% Artem Bityutskiy 68 0.6% Hans de Goede 68 0.6% Takashi Iwai 64 0.6%
By changed lines Paul Gortmaker 44000 5.7% Viresh Kumar 20425 2.7% Steven Rostedt 14615 1.9% H. Hartley Sweeten 13083 1.7% Dave Airlie 12217 1.6% Sakari Ailus 10835 1.4% Dong Aisheng 10574 1.4% Sonic Zhang 10494 1.4% Paul Walmsley 10084 1.3% Ben Skeggs 10000 1.3% Rob Herring 9886 1.3% Sascha Hauer 9602 1.3% Stephen Warren 9365 1.2% Parav Pandit 8846 1.2% Nicholas Bellinger 8704 1.1% Linus Walleij 8496 1.1% Shawn Guo 7797 1.0% David S. Miller 7445 1.0% Phil Edworthy 7189 0.9% Sam Ravnborg 6752 0.9% Hans Verkuil 6718 0.9% Alexander Shishkin 6668 0.9% Tejun Heo 6579 0.9% Greg Kroah-Hartman 6524 0.9% Vladimir Serbinenko 6451 0.8%
In the quantity category (remember, we don't judge quality), I did a large number of cleanup patches removing old USB logging macros from the system, which resulted in the majority of my changes in the 3.5 kernel. Axel contributed a great number of regulator driver fixes and enhancements, and Mark Brown did the majority of his work in the sound system-on-a-chip drivers area. H. Hartley Sweeten has been working on cleaning up the Comedi (data acquisition) drivers to get them ready to move out of the staging area of the kernel. This work has him showing up in these statistics for the first time. And rounding out the top five is David Miller with a large number of networking core and driver patches.
Along with H. Hartley Sweeten, Daniel Vetter is also a newcomer to the "top changesets" list. His contributions came from numerous changes and enhancements to the Intel graphics drivers. Although Hans Verkuil is also a name that might not be familiar to many, his contributions to the Video4Linux drivers and core code show he is a core contributor to a subsystem that many users rely on every day.
Considering the statistics in lines changed, Paul Gortmaker leads by virtue of the fact that he deleted all of the old Token Ring drivers from the kernel. Viresh Kumar did a lot of SPEAr processor and driver work, adding numerous new drivers for the platform. Steven Rostedt did a large amount of development on ftrace and ktest (a kernel-testing tool). H. Hartley Sweeten did the aforementioned Comedi driver cleanup work, and Dave Arlie made major changes in the area of graphics drivers.
Reviewing the work
All kernel patches are reviewed and "Signed-off-by" a subsystem maintainer before they are committed to the Linux kernel. The developers with the most sign-offs for the 3.5 kernel were as follows:
Developers with the most signoffs (total 20391) Greg Kroah-Hartman 1216 6.0% David S. Miller 922 4.5% Mauro Carvalho Chehab 605 3.0% Mark Brown 549 2.7% John W. Linville 493 2.4% Linus Torvalds 424 2.1% Andrew Morton 373 1.8% Daniel Vetter 268 1.3% Dave Airlie 255 1.3% Al Viro 197 1.0% Axel Lin 191 0.9% Trond Myklebust 173 0.8% Arnaldo Carvalho de Melo 165 0.8% James Bottomley 164 0.8% Artem Bityutskiy 157 0.8% Kyungmin Park 156 0.8% Samuel Ortiz 154 0.8% Linus Walleij 153 0.8% Ingo Molnar 150 0.7% Wey-Yi W Guy 146 0.7% Thomas Gleixner 139 0.7% Stephen Warren 136 0.7% H. Hartley Sweeten 135 0.7% Shawn Guo 131 0.6% Paul Mundt 128 0.6%
I ended up doing the most sign-offs for this kernel release because of many changes in the staging and USB subsystems. David Miller follows with his work in the networking and networking driver trees, as well as in the IDE drivers. Mauro is the maintainer of the Video4Linux subsystem, Mark Brown is the maintainer of the embedded sound drivers, and John Linville is the maintainer of the wireless driver subsystem.
These numbers reflect the picture of what has been happening in the past few kernel releases, with the majority of changes happening in the staging and networking areas of the kernel.
Who sponsored this work
Here is the list of the companies who sponsored the developers doing the work for this kernel release, and the number of changes attributed to them:
Top changeset contributors by employer (None) 1343 12.3% Red Hat 1123 10.2% Intel 1061 9.7% (Unknown) 860 7.8% Linaro 519 4.7% Novell 440 4.0% Texas Instruments 313 2.9% IBM 282 2.6% Linux Foundation 279 2.5% 265 2.4% Samsung 251 2.3% Oracle 204 1.9% Renesas Electronics 201 1.8% MiTAC 191 1.7% NVIDIA 188 1.7% Wolfson Microelectronics 187 1.7% (Consultant) 160 1.5% NetApp 153 1.4% Vision Engraving Systems 135 1.2% Qualcomm 121 1.1%
Longtime readers of this series of articles will notice that Linaro has appeared in the top 5 kernel developer companies by number of contributions for the first time. This is due to the increased number of patches Linaro has been contributing, as well as the organization's wish to have the member company employees' contributions be counted as coming from Linaro, instead of the member company itself, as we had previously been doing.
A newcomer to the top 20 companies is Vision Engraving Systems, thanks to the Comedi development work from H. Hartley Sweeten. With his work, hopefully this subsystem can move out of the staging area of the kernel in a future release.
Other than the large jump from Linaro, the other companies in the top 25 are well known. Even NVIDIA—despite Linus's well-publicized, and in my opinion well-deserved, criticism of its Linux graphics driver development efforts—continues to be a large contributor to the kernel in the area of embedded processor support for its products. Texas Instruments, Samsung, MiTAC, Wolfson Microelectronics, Qualcomm, Renesas, and Nokia are also primarily focused in the embedded Linux area, showing the wide range of ongoing company support for Linux in embedded systems.
Work continues as usual
With the 3.5 kernel release, the number of contributors remains as
high as previous releases, the rate of contributions is greater than
ever (as measured by number of patches per day), and the rate of increase
in the size of the kernel code remains the same as it has been for the past
year.
This shows that the kernel development community is still growing, and
maintaining its incredibly rapid development cycle, ensuring that
Linux remains the largest software engineering project ever.
Index entries for this article | |
---|---|
Kernel | Releases/3.5 |
GuestArticles | Kroah-Hartman, Greg |
(Log in to post comments)
Who wrote 3.5
Posted Jul 26, 2012 7:16 UTC (Thu) by viiru (subscriber, #53129) [Link]
> Renesas, and Nokia are also primarily focused in the embedded Linux area
Nokia? I can't see Nokia mentioned in employers list, was that a mistake? I'd also find it somewhat surprising if Nokia did appear on this list, considering that they no longer have any Linux-based devices in development, and that they have in my understanding laid off their Linux developers.
Who wrote 3.5
Posted Jul 26, 2012 13:11 UTC (Thu) by jake (editor, #205) [Link]
An earlier version of the article had a longer list of employers (25 instead of 20) and Nokia did appear at #23 (99 changesets, 0.9%) ... when we revised the list, we forgot to remove Nokia in the text (Renasas too for that matter). Sorry for the confusion.
jake
Who wrote 3.5
Posted Jul 26, 2012 13:13 UTC (Thu) by jake (editor, #205) [Link]
sigh, I shouldn't post comments before coffee ... Renasas is there in the list, of course ...
jake
Who wrote 3.5
Posted Aug 3, 2012 18:00 UTC (Fri) by jake (editor, #205) [Link]
heh, it's right in the article, just not in the comments ... i can't be responsible for editors misspelling things in the comments ... oh, wait :)
jake
Who wrote 3.5
Posted Jul 26, 2012 14:06 UTC (Thu) by intgr (subscriber, #39733) [Link]
Who wrote 3.5
Posted Jul 26, 2012 16:13 UTC (Thu) by iabervon (subscriber, #722) [Link]
Who wrote 3.5
Posted Jul 28, 2012 15:31 UTC (Sat) by jengelh (subscriber, #33263) [Link]
Requiring less code is indeed a wonderful thing.
AHCI is one of these masterpieces: a single driver driving many consumer-level disk chipsets at once. The sound club tried something similar with AC97 and HDA. Why can't we have a unified HW API like that for further types of silicon as well, like, network cards?
Who wrote 3.5
Posted Aug 6, 2012 14:48 UTC (Mon) by nhippi (guest, #34640) [Link]
The AMD GPU's would need more work. OTOH much that is on the MESA/Xorg side rather than in the kernel.
Who wrote 3.5
Posted Aug 23, 2012 13:37 UTC (Thu) by daenzer (subscriber, #7050) [Link]
Who wrote 3.5
Posted Aug 23, 2012 15:17 UTC (Thu) by intgr (subscriber, #39733) [Link]
Ok let's have a look at the numbers. Here are the stats for AMD in particular...
3.5 : missing
3.4 : changesets 1.2% #19, lines 1.5% #15
3.3 : missing
3.2 : missing
3.1 : missing
3.0 : changesets 1.8% #12
2.6.39: changesets 1.3% #16
2.6.38: changesets 2.0% #9 , lines 1.1% #19
2.6.37: changesets 1.5% #14
2.6.36: changesets 1.4% #14
2.6.35: changesets 1.7% #10
2.6.34: changesets 1.3% #17, lines 1.5% #19
2.6.33: changesets 1.6% #13, lines 0.8% #18
2.6.32: changesets 2.3% #9
2.6.31: changesets 1.2% #13
2.6.30: changesets N/A, lines 2.1% #10
I'm afraid you mistook an exception for the rule. AMD had significant presence in all releases between 2.6.30 - 3.0, but then suddenly disappeared (apart from one exception that is 3.4).
(I created an index of LWN development statistics articles for easier reference here:
http://kernelnewbies.org/DevelopmentStatistics)
Who wrote 3.5.x
Posted Jul 26, 2012 21:25 UTC (Thu) by ballombe (subscriber, #9523) [Link]
I am sure the article author will agree ;).
Who wrote 3.5.x
Posted Jul 26, 2012 22:31 UTC (Thu) by gregkh (subscriber, #8) [Link]
Who wrote 3.5
Posted Jul 31, 2012 7:25 UTC (Tue) by nab (guest, #34463) [Link]
Who wrote 3.5
Posted Aug 1, 2012 17:27 UTC (Wed) by nevets (subscriber, #11875) [Link]
Hmm, I got the top 3 spot for most lines changed due to my libtraceevents library finally making it into the kernel tools directory from trace-cmd and incorporated into perf.Should we really be posting changes to the tools directory as those that wrote 3.5 kernel?
Hey! I like being at #3, but really, it wasn't for my work in the kernel.
$ git log -p --author=rostedt v3.4..v3.5 tools |diffstat | tail -1 43 files changed, 13740 insertions(+), 6963 deletions(-) $ git log -p --author=rostedt v3.4..v3.5 arch include kernel |diffstat|tail -1 27 files changed, 875 insertions(+), 453 deletions(-)
Who wrote 3.5
Posted Aug 4, 2012 23:37 UTC (Sat) by mathstuf (subscriber, #69389) [Link]
Who wrote 3.5
Posted Aug 5, 2012 0:10 UTC (Sun) by nevets (subscriber, #11875) [Link]
Who wrote 3.5
Posted Aug 5, 2012 0:41 UTC (Sun) by mathstuf (subscriber, #69389) [Link]