Statistics of Linux Kernel development Tsugikazu SHIBATA NEC - - PowerPoint PPT Presentation

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Statistics of Linux Kernel development Tsugikazu SHIBATA NEC - - PowerPoint PPT Presentation

Aug 14, 2023 129 likes •406 views

Statistics of Linux Kernel development Tsugikazu SHIBATA NEC Oct.22 nd 2009 Japan Linux Symposium @Akihabara Convention Hall $ who am i Name : Tsugikazu SHIBATA Company: OSS promotion center NEC Job: Standing in between the

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Statistics of Linux Kernel development

Tsugikazu SHIBATA NEC Oct.22nd 2009 Japan Linux Symposium @Akihabara Convention Hall

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$ who am i

  • Name : Tsugikazu SHIBATA
  • Company: OSS promotion center NEC
  • Job: Standing in between the community and

industry, fostering industry's developer to work with community

  • Maintaining: Documentation/ja_JP/HOWTO etc
  • Japanese translated version of HOWTO and other

documents merged in 2.6.23

  • Providing Google calendar feed of Linux kernel

release history

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Source code growth of Linux

  • Now, Linux has 11.9ML with 409K files in 2.6.31.
  • Growing 18%, about 1.85ML in this year(=last 4 versions)
  • 4-5 releases per year
  • Over 10ML of codes since 2.6.28
  • 6 years since 2.6.0 (was released in 2003/12/18)

[2004] [2005] [2006] [2007] [2008] [2009]

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Development days for release

  • Average of last 4 releases: 83 days
  • Average of last 10 releases: 86 days
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Number of developers sent patch

  • Patches from 1291 developers were merged in 2.6.31
  • About twice compared with 2.6.15 (early 2006)
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Send patch and mailing list

  • 141 mailing lists in VGER.KERNEL.ORG.
  • Subscribers in Linux-kernel mailing list are 5491.
  • Lots of subsystem mailing lists are also there.
  • Total subscribers of 141 mailing lists are 31594.

Subsystem Mailing list ... Linux-kernel Mailing list Developers Subsystem Maintainers Linux release

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Number of MAINTAINERS

  • Number of Maintainers are increasing with the source code

growth.

  • 767 maintainers in 2.6.31
  • it is twice with 2.6.10 as same as source lines become twice
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Linux kernel development Community

1: Linus 10-15: Core maintainers 80-90: kernel Summit maintainers 760: MAINTAINERS 1300: Developers 5400: LKML subscribers 31000: Linux subsystem mailing lists subscribers

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Development Process

  • Merge window and Release candidates
  • 2 weeks of merge window just after kernel released
  • Each RC takes a week or 10 days, continue 8-9 times

2.6.N 2.6.N+1

  • rc1
  • rc3
  • rc..
  • rc2

Merge Window Week: 2 11-12 New features Stabilize Kernel 2.6.26 2.6.27 2.6.28 2.6.29 2.6.30 2.6.31 Max -RC

  • rc9
  • rc9
  • rc9
  • rc8
  • rc8
  • rc9
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Linux-next and stable releases

  • Linux-next:
  • Merging 144 of subsystem trees to prepare next merge

window

  • Do automated build test and maintainers get notification

about build problems on almost daily basis

2.6.N 2.6.N+1

  • rc1
  • rc..

Linux-next

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Linux-next and stable releases

  • Stable releases:
  • Stable version of Linux kernel
  • Including bug fixes and security fixes
  • 4 digits' name and started from 2.6.11.1
  • Continue until the next new version released (at least)

2.6.N 2.6.N+1

  • rc1
  • rc..

Linux-next Stable release

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Lines of Code Difference w/ prev. ver. % 2.6.11 6624076 128534 2.0% 2.6.12 6777860 153784 2.3% 2.6.13 6988800 210940 3.1% 2.6.14 7143233 154433 2.2% 2.6.15 7290070 146837 2.1% 2.6.16 7480062 189992 2.6% 2.6.17 7588014 107952 1.4% 2.6.18 7752846 164832 2.2% 2.6.19 7976221 223375 2.9% 2.6.20 8102533 126312 1.6% Lines of Code Difference w/ prev. ver. % 2.6.21 8246517 143984 1.8% 2.6.22 8499410 252893 3.1% 2.6.23 8566606 67196 0.8% 2.6.24 8859683 293077 3.4% 2.6.25 9232541 372858 4.2% 2.6.26 9411790 179249 1.9% 2.6.27 9630023 218233 2.3% 2.6.28 10115662 485639 5.0% 2.6.29 10930802 815140 8.1% 2.6.30 11557329 626527 5.7% 2.6.31 11966482 409153 3.5%

Source code growth

  • 2-5% growth of lines in version (average: 584KL)
  • 1.85ML grown in the total of the last 4 versions
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Patch example

  • Patch includes changes for lines
  • Remove and add with line by line basis
  • -- a/Documentation/ja_JP/HOWTO

+++ b/Documentation/ja_JP/HOWTO

@@ -412,13 +420,32 @@ Linux-kernel メーリングリストで収集された多数のパッチと同 bugzilla.kernel.org は Linux カーネル開発者がカーネルのバグを追跡する 場所です。ユーザは見つけたバグの全てをこのツールで報告すべきです。 どう kernel bugzilla を使うかの詳細は、以下を参照してください -

  • http://test.kernel.org/bugzilla/faq.html
  • + http://bugzilla.kernel.org/page.cgi?id=faq.html
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Lines of Code Patch add+del % 2.6.13 6988800 687287

10.1

2.6.14 7143233 565473

8.1

2.6.15 7290070 918325

12.9

2.6.16 7480062 657461

9.0

2.6.17 7588014 797260

10.7

2.6.18 7752846 656463

8.7

2.6.19 7976221 909700

11.7

2.6.20 8102533 446251

5.6

2.6.21 8246517 542521

6.7

2.6.22 8499410 885487

10.7

Lines of Code Patch add+del % 2.6.23 8566606 889418

10.5

2.6.24 8859683 1533400

17.9

2.6.25 9232541 1354956

15.3

2.6.26 9411790 1143004

12.4

2.6.27 9630023 2311242

24.6

2.6.28 10115662 1634825

17.0

2.6.29 10930802 2233640

22.1

2.6.30 11557329 1839720

16.8

2.6.31 11966482 1622731

14.0

Add and delete Lines by the patches

  • Add and delete lines by the patches are 1.6ML-2.2ML
  • It is about 10-20% of the source lines.
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Summary

  • Linux 2.6 development is now 6 years since

2004.

  • People sent patch are about 1300 and it is

twice compared with 3 years ago.

  • The number of maintainers becomes twice

and it's now 760.

  • 4-5 kernel version were released in a year,

with 18% growth rate(1.85ML added).

  • 5500 people are subscribing Linux-kernel

mailing list.

  • 140 of related mailing lists and total

subscribers are about 31000.

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Summary

  • Linux is now over 10ML of source code since

early this year.

  • 2.6.31, the latest kernel has 12ML of source

code in 409K of files.

  • Release cycle of Linux is about 83-86 days

with 8-9 times of release candidates.

  • 3-5% of source code, 580KL are growing in

each version.

  • 10-20% of source code,1.6ML – 2.2ML are

modified in each version by the patches.

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Does Linux bloated and huge?

In the discussion about performance drops on database benchmark, Linus said ”kernel is getting bloated and huge, yes it's problem”. Also “it's unavoidable due to the new features get added with each releases”.

$ pwd /home/ts/linux-2.6 $ ls COPYING Makefile crypto init net tools CREDITS README drivers ipc samples usr Documentation REPORTING-BUGS firmware kernel scripts virt Kbuild arch fs lib security MAINTAINERS block include mm sound From http://lwn.net/Articles/354835/

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Source line share of 2nd dirs.

  • Major 7 directories take 95%.
  • This mix has not been changed since 3 years ago.

2.6.20 2.6.21 2.6.22 2.6.23 2.6.24 2.6.25 2.6.26 2.6.27 2.6.28 2..6.29 2.6.30 2.6.31 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

45% 45% 45% 45% 46% 46% 46% 46% 47% 49% 50% 50% 20% 20% 20% 20% 20% 20% 20% 23% 24% 23% 23% 23%

9% 9% 8% 8% 8% 8% 8% 8% 8% 8% 8% 8% 6% 6% 6% 6% 6% 6% 6% 6% 5% 5% 5% 5% 5% 6% 5% 5% 5% 5% 5% 5% 5% 4% 4% 4% 9% 9% 10% 10% 9% 9% 9% 6% 4% 4% 3% 3% 3% 3% 3% 3% 3% 3% 3% 3% 3% 3% 2% 2%

usr samples virt init ipc . block lib firmware security crypto scripts mm kernel Documentation include sound net fs arch drivers

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Growth of configuration file

  • # of Kconfig files now 610 (2.6.31)
  • About 40 files were added in each of the last 4

versions.

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Growth of config items

  • Now, # of config items are 9200 in 2.6.31
  • Config items are growing 300-400 in each version
  • About 3-4% growth in each of the last 4 versions
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In between the Performance and Features

  • Seems no specific bloat in the level of

subsystem directories. Mix of source lines of directories were not changed.

  • Choosing good configuration option may be a

solution.

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Linux upstream and distros

  • Distros take 6-7 months from upstream Kernel

release to provide commercial products for it's integration and testing.

  • New versions releasing every 2-3 years.

2004 2005 2006 2007 2008 2009

2.6.9 Oct. Fedora3 Dec. RHEL4 Feb. 2.6.18 Sep. Fedora6 Oct. RHEL5 Mar. 2.6.16 Mar.

SUSELinux10.0 May.

SLES10 Jul. 2.6.27 Oct.

OpenSUSE11.1 Dec.

SLES11 Mar.

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My some suggestions to industry

  • Creating your own Linux will never be realized.
  • Your own feature will become obsolete. Similar

feature will be implemented by more excellent approach by the community.

  • Because of 1300 people VS your team
  • Adding your own feature to Linux for your

customer?

  • You will see the problem for bug/security fix in the

future.

  • Huge number of lines are changed (10-20% and 1.6-

2.2ML by the patches) in a year.

  • Having your own patch for your customer?
  • You should try to merge to upstream,
  • therwise you will have to make your own patch

forever.

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My other suggestions

  • If you need to decrease the QA engineering costs,
  • Assign someone to work for QA activity with the

community.

  • Better quality in earlier phase leads smaller cost in later

phase

  • If you need more knowledge of Linux for customer

support

  • Assign someone to work for the community.
  • He can create human network and get much information for

customer support.

  • If you need to educate your engineer,
  • Assign someone to work for the community
  • Your engineer will get good suggestions and much more

technical skills from many of great people in the community.

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Why don't you join the community?

  • Start from HOWTO document
  • It is in the Linux kernel, Japanese, Korean and

Chinese versions are also there

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Thank you. ありがとう