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Who wrote - and approved - 2.6.22
The 2.6.22 kernel is getting closer to its final state with its official
release likely to happen near the end of this month. Patches are still
being added to the mainline repository, but things have stabilized enough
that it makes sense to take a look at where the code came from this time
around. Accordingly, your editor has fixed up his scripts and cranked
through the changesets added in this kernel development cycle.
As of this writing, just over 6,000 changesets have been accepted for 2.6.22. Those patches were contributed by 885 different developers, added 494,000 lines, and deleted 241,000 other lines (without counting renames, which would otherwise increase both numbers by about 60,000 lines). That makes 2.6.22 a large change relative to its immediate predecessors:
Here's the top contributors of those changes:
Bryan Wu makes it to the top of the list of contributors (by lines changed) by virtue of being the person to contribute support for the Blackfin architecture. David Howells contributed the AF_RXRPC and AFS filesystem work; Marcelo Tosatti wrote the OLPC "Libertas" wireless driver, and Jiri Benc's name appears on the mac80211 stack. When broken down by employer, the (approximate, as always) numbers come out like this:
One thing which jumps out here is that the amount of code contributed by developers known to be working on their own time has dropped; 2.6.22 will be one of the most corporate kernels yet. Looking at the developers who put Signed-off-by lines onto patches yields some interesting results. If one tabulates all 12,678 signoffs in 2.6.22, the results look like this:
All authors must sign off on their code. Additionally, any maintainer who passes a patch up toward the mainline adds a signoff indicating that he or she believes the code is legitimate and suitable for inclusion. If one excludes signoffs by the author of each patch, the remaining 7,000 signoffs are (almost) all by people through whom the code has passed (a few of them are by additional authors of the patch). Those adding non-author signoffs can thus be thought of as the gatekeepers through whom each patch must pass. Non-author signoffs break down like this:
In summary, 80% of the patches merged into the mainline kernel passed through the twenty developers listed above. One can take another step, and look at the number of non-author signoffs by employer:
The bottom line: while Linux kernel development is a highly distributed activity, the work of several hundred developers is channeled through a surprisingly small number of individuals, and an even smaller number of companies on its way into the mainline. (Log in to post comments)
Who wrote - and approved - 2.6.22 Posted Jun 14, 2007 2:45 UTC (Thu) by pr1268 (subscriber, #24648) [Link] A positive perspective I see is that the 'corporate' bias in the recent kernels (and a list of the very companies supporting this development) as a sign that Linux is indeed a valid, viable, and stable alternative to proprietary operating system (and related) software. Either that, or (as I've stated before) the companies who throw resources1 at Linux are the same companies who have the most to gain from its continued development. 1Perhaps "throw resources" sounds a little harsh, but I mean it in the nicest sense of the term.
Who wrote - and approved - 2.6.22 Posted Jun 14, 2007 8:37 UTC (Thu) by xav (subscriber, #18536) [Link] I think having a lot of "corporate" reviewers is a good thing. Doing codereview isn't always the most interesting thing to do, just developing is far more fun. So having a lot of people payed by corps to do the tedious work of reviewing code, while independant developers continue to write their crappy drivers is IMHO a very good equilibrium point.
Xav
Who wrote - and approved - 2.6.22 Posted Jun 14, 2007 20:48 UTC (Thu) by elanthis (guest, #6227) [Link] Silly question, but how do 20% of patches get into mainline without passing through Linux (or even Andrew) ?
Is it just that Linus doesn't sign-off when he merges patches, so the sign-offs from him are those he reviewed personally versus those reviewed by some other "trusted lieutenant" not on that top 20 list?
Who wrote - and approved - 2.6.22 Posted Jun 15, 2007 0:23 UTC (Fri) by aegl (subscriber, #37581) [Link] Yes. When Linus does a "pull" from a subsystem maintainer's tree, none of the changesets get his sign-off.
Who wrote - and approved - 2.6.22 Posted Jun 15, 2007 16:25 UTC (Fri) by aegl (subscriber, #37581) [Link] It isn't a sure bet that a change-set with a sign-off from Linus has actually been reviewed by him either ... when Andrew Morton sends a "patch-bomb" with several hundred e-mail messages moving code from -mm to Linus, chances are that Linus does not sit down and read each and every one of them. But they will all get a "Signed-off-by" from Linus because the GIT tool that applies patches from a mailbox adds a sign-off to each commit that is applied that way.If Andrew started using a GIT tree to transfer to Linus, then many of those "Signed-off-by: Linus" commits would just end the trail-of-blame with Andrew's sign-off. This is sort of documented in Documentation/SubmittingPatches: "The Signed-off-by: tag indicates that the signer was involved in the development of the patch, or that he/she was in the patch's delivery path.". "In the patches delivery path" does not necessarily mean "Reviewed by". So some care is needed when interpreting this data since some quite large parts are affected by the mechanisms used to move changes around.
Who wrote - and approved - 2.6.22 Posted Jun 16, 2007 13:05 UTC (Sat) by hingo (guest, #14792) [Link] Surely Andrew Morton uses GIT to transfer code to Linus?If the opposite was true, then we would have just uncovered a major scoop, that Linus doesn't really do anything at all anymore, just sits around taking credit for not coding anything, not approving anything.
Who wrote - and approved - 2.6.22 Posted Jun 16, 2007 18:02 UTC (Sat) by dlang (✭ supporter ✭, #313) [Link] the facts are in between these two.
as I understand it, Andrew doesn't normally use git to send patches to Linus, but at the same time signed off by indicates that the person is vouching for the patch. I don't think that it's done automaticaly by the git scripts (remember, they are used by projects that don't do 'signed off by' lines)
Linus has said many times that his job is more to be a gatekeeper then a coder nowdays, but he still writes and modifies code.
David Lang
Who wrote - and approved - 2.6.22 Posted Jun 17, 2007 9:25 UTC (Sun) by hingo (guest, #14792) [Link] Ok. What I was really wondering was that Andrew Signs off 0.8% more patches than Linus, so mathematically it's impossible to claim that some script by Linux automatically signs off everything Andrew has signed?
Who wrote - and approved - 2.6.22 Posted Jun 15, 2007 21:23 UTC (Fri) by jkm (guest, #14176) [Link] It's fairly misleading to see Google listed at the top of non-author signoffs by employer, considering only two of the signoffs came from someone other than Andrew.
Who wrote - and approved - 2.6.22 Posted Jun 20, 2007 21:53 UTC (Wed) by roelofs (guest, #2599) [Link] It's fairly misleading to see Google listed at the top of non-author signoffs by employer, considering only two of the signoffs came from someone other than Andrew.It's hardly any different for Linus/Linux Foundation, is it? Keep in mind that there is at least a vague correlation between number of signoffs performed and (paid) effort expended. Red Hat just spreads theirs around a bit more. ;-) Greg
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