€•ó      Œsphinx.addnodes”Œdocument”“”)”}”(Œ	rawsource”Œ ”Œchildren”]”(Œtranslations”ŒLanguagesNode”“”)”}”(hhh]”(h Œpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ%/translations/zh_CN/process/2.Process”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/zh_TW/process/2.Process”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/it_IT/process/2.Process”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/ja_JP/process/2.Process”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/ko_KR/process/2.Process”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒPortuguese (Brazilian)”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/pt_BR/process/2.Process”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh–sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/sp_SP/process/2.Process”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒtarget”“”)”}”(hŒ.. _development_process:”h]”h}”(h]”h ]”h"]”h$]”h&]”Œrefid”Œdevelopment-process”uh1hµh´Khhh²hh³Œ?/var/lib/git/docbuild/linux/Documentation/process/2.Process.rst”ubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒ!How the development process works”h]”hŒ!How the development process works”…””}”(hhËh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhhÆh²hh³hÃh´KubhŒ	paragraph”“”)”}”(hX²  Linux kernel development in the early 1990s was a pretty loose affair,
with relatively small numbers of users and developers involved.  With a
user base in the millions and with some 2,000 developers involved over the
course of one year, the kernel has since had to evolve a number of
processes to keep development happening smoothly.  A solid understanding of
how the process works is required in order to be an effective part of it.”h]”hX²  Linux kernel development in the early 1990s was a pretty loose affair,
with relatively small numbers of users and developers involved.  With a
user base in the millions and with some 2,000 developers involved over the
course of one year, the kernel has since had to evolve a number of
processes to keep development happening smoothly.  A solid understanding of
how the process works is required in order to be an effective part of it.”…””}”(hhÛh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KhhÆh²hubhÅ)”}”(hhh]”(hÊ)”}”(hŒThe big picture”h]”hŒThe big picture”…””}”(hhìh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhhéh²hh³hÃh´KubhÚ)”}”(hXì  The Linux kernel uses a loosely time-based, rolling release development
model.  A new major kernel release (which we will call, as an example, 9.x)
[1]_ happens every two or three months, which comes with new features,
internal API changes, and more. A typical release can contain about 13,000
changesets with changes to several hundred thousand lines of code. Recent
releases, along with their dates, can be found at `Wikipedia
<https://en.wikipedia.org/wiki/Linux_kernel_version_history>`_.”h]”(hŒ”The Linux kernel uses a loosely time-based, rolling release development
model.  A new major kernel release (which we will call, as an example, 9.x)
”…””}”(hhúh²hh³Nh´NubhŒfootnote_reference”“”)”}”(hŒ[1]_”h]”hŒ1”…””}”(hj  h²hh³Nh´Nubah}”(h]”Œid1”ah ]”h"]”h$]”h&]”hÁŒid2”Œdocname”Œprocess/2.Process”uh1j  hhúŒresolved”KubhX
   happens every two or three months, which comes with new features,
internal API changes, and more. A typical release can contain about 13,000
changesets with changes to several hundred thousand lines of code. Recent
releases, along with their dates, can be found at ”…””}”(hhúh²hh³Nh´NubhŒ	reference”“”)”}”(hŒI`Wikipedia
<https://en.wikipedia.org/wiki/Linux_kernel_version_history>`_”h]”hŒ	Wikipedia”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œname”Œ	Wikipedia”Œrefuri”Œ:https://en.wikipedia.org/wiki/Linux_kernel_version_history”uh1j  hhúubh¶)”}”(hŒ=
<https://en.wikipedia.org/wiki/Linux_kernel_version_history>”h]”h}”(h]”Œ	wikipedia”ah ]”h"]”Œ	wikipedia”ah$]”h&]”Œrefuri”j.  uh1hµŒ
referenced”KhhúubhŒ.”…””}”(hhúh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Khhéh²hubhŒfootnote”“”)”}”(hX-  Strictly speaking, the Linux kernel does not use semantic versioning
number scheme, but rather the 9.x pair identifies major release
version as a whole number. For each release, x is incremented,
but 9 is incremented only if x is deemed large enough (e.g.
Linux 5.0 is released following Linux 4.20).
”h]”(hŒlabel”“”)”}”(hŒ1”h]”hŒ1”…””}”(hjO  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jM  hjI  ubhÚ)”}”(hX,  Strictly speaking, the Linux kernel does not use semantic versioning
number scheme, but rather the 9.x pair identifies major release
version as a whole number. For each release, x is incremented,
but 9 is incremented only if x is deemed large enough (e.g.
Linux 5.0 is released following Linux 4.20).”h]”hX,  Strictly speaking, the Linux kernel does not use semantic versioning
number scheme, but rather the 9.x pair identifies major release
version as a whole number. For each release, x is incremented,
but 9 is incremented only if x is deemed large enough (e.g.
Linux 5.0 is released following Linux 4.20).”…””}”(hj]  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KhjI  ubeh}”(h]”j  ah ]”h"]”Œ1”ah$]”h&]”j  aj  j  uh1jG  h³hÃh´Khhéh²hj  KubhÚ)”}”(hX  A relatively straightforward discipline is followed with regard to the
merging of patches for each release.  At the beginning of each development
cycle, the "merge window" is said to be open.  At that time, code which is
deemed to be sufficiently stable (and which is accepted by the development
community) is merged into the mainline kernel.  The bulk of changes for a
new development cycle (and all of the major changes) will be merged during
this time, at a rate approaching 1,000 changes ("patches," or "changesets")
per day.”h]”hX  A relatively straightforward discipline is followed with regard to the
merging of patches for each release.  At the beginning of each development
cycle, the â€œmerge windowâ€ is said to be open.  At that time, code which is
deemed to be sufficiently stable (and which is accepted by the development
community) is merged into the mainline kernel.  The bulk of changes for a
new development cycle (and all of the major changes) will be merged during
this time, at a rate approaching 1,000 changes (â€œpatches,â€ or â€œchangesetsâ€)
per day.”…””}”(hjr  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Khhéh²hubhÚ)”}”(hŒì(As an aside, it is worth noting that the changes integrated during the
merge window do not come out of thin air; they have been collected, tested,
and staged ahead of time.  How that process works will be described in
detail later on).”h]”hŒì(As an aside, it is worth noting that the changes integrated during the
merge window do not come out of thin air; they have been collected, tested,
and staged ahead of time.  How that process works will be described in
detail later on).”…””}”(hj€  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K'hhéh²hubhÚ)”}”(hXÃ  The merge window lasts for approximately two weeks.  At the end of this
time, Linus Torvalds will declare that the window is closed and release the
first of the "rc" kernels.  For the kernel which is destined to be 9.x,
for example, the release which happens at the end of the merge window will
be called 9.x-rc1.  The -rc1 release is the signal that the time to
merge new features has passed, and that the time to stabilize the next
kernel has begun.”h]”hXÇ  The merge window lasts for approximately two weeks.  At the end of this
time, Linus Torvalds will declare that the window is closed and release the
first of the â€œrcâ€ kernels.  For the kernel which is destined to be 9.x,
for example, the release which happens at the end of the merge window will
be called 9.x-rc1.  The -rc1 release is the signal that the time to
merge new features has passed, and that the time to stabilize the next
kernel has begun.”…””}”(hjŽ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K,hhéh²hubhÚ)”}”(hX`  Over the next six to ten weeks, only patches which fix problems should be
submitted to the mainline.  On occasion a more significant change will be
allowed, but such occasions are rare; developers who try to merge new
features outside of the merge window tend to get an unfriendly reception.
As a general rule, if you miss the merge window for a given feature, the
best thing to do is to wait for the next development cycle.  (An occasional
exception is made for drivers for previously-unsupported hardware; if they
touch no in-tree code, they cannot cause regressions and should be safe to
add at any time).”h]”hX`  Over the next six to ten weeks, only patches which fix problems should be
submitted to the mainline.  On occasion a more significant change will be
allowed, but such occasions are rare; developers who try to merge new
features outside of the merge window tend to get an unfriendly reception.
As a general rule, if you miss the merge window for a given feature, the
best thing to do is to wait for the next development cycle.  (An occasional
exception is made for drivers for previously-unsupported hardware; if they
touch no in-tree code, they cannot cause regressions and should be safe to
add at any time).”…””}”(hjœ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K4hhéh²hubhÚ)”}”(hXL  As fixes make their way into the mainline, the patch rate will slow over
time.  Linus releases new -rc kernels about once a week; a normal series
will get up to somewhere between -rc6 and -rc9 before the kernel is
considered to be sufficiently stable and the final release is made.
At that point the whole process starts over again.”h]”hXL  As fixes make their way into the mainline, the patch rate will slow over
time.  Linus releases new -rc kernels about once a week; a normal series
will get up to somewhere between -rc6 and -rc9 before the kernel is
considered to be sufficiently stable and the final release is made.
At that point the whole process starts over again.”…””}”(hjª  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K>hhéh²hubhÚ)”}”(hŒNAs an example, here is how the 5.4 development cycle went (all dates in
2019):”h]”hŒNAs an example, here is how the 5.4 development cycle went (all dates in
2019):”…””}”(hj¸  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KDhhéh²hubhŒblock_quote”“”)”}”(hX{  ==============  ===============================
September 15    5.3 stable release
September 30    5.4-rc1, merge window closes
October 6       5.4-rc2
October 13      5.4-rc3
October 20      5.4-rc4
October 27      5.4-rc5
November 3      5.4-rc6
November 10     5.4-rc7
November 17     5.4-rc8
November 24     5.4 stable release
==============  ===============================
”h]”hŒtable”“”)”}”(hhh]”hŒtgroup”“”)”}”(hhh]”(hŒcolspec”“”)”}”(hhh]”h}”(h]”h ]”h"]”h$]”h&]”Œcolwidth”Kuh1jÖ  hjÓ  ubj×  )”}”(hhh]”h}”(h]”h ]”h"]”h$]”h&]”Œcolwidth”Kuh1jÖ  hjÓ  ubhŒtbody”“”)”}”(hhh]”(hŒrow”“”)”}”(hhh]”(hŒentry”“”)”}”(hhh]”hÚ)”}”(hŒSeptember 15”h]”hŒSeptember 15”…””}”(hjû  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KHhjø  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjó  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.3 stable release”h]”hŒ5.3 stable release”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KHhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjó  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjî  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒSeptember 30”h]”hŒSeptember 30”…””}”(hj2  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KIhj/  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj,  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.4-rc1, merge window closes”h]”hŒ5.4-rc1, merge window closes”…””}”(hjI  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KIhjF  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj,  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjî  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒ	October 6”h]”hŒ	October 6”…””}”(hji  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KJhjf  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjc  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.4-rc2”h]”hŒ5.4-rc2”…””}”(hj€  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KJhj}  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjc  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjî  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒ
October 13”h]”hŒ
October 13”…””}”(hj   h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KKhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjš  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.4-rc3”h]”hŒ5.4-rc3”…””}”(hj·  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KKhj´  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjš  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjî  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒ
October 20”h]”hŒ
October 20”…””}”(hj×  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KLhjÔ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjÑ  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.4-rc4”h]”hŒ5.4-rc4”…””}”(hjî  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KLhjë  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjÑ  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjî  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒ
October 27”h]”hŒ
October 27”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KMhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.4-rc5”h]”hŒ5.4-rc5”…””}”(hj%  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KMhj"  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjî  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒ
November 3”h]”hŒ
November 3”…””}”(hjE  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KNhjB  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj?  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.4-rc6”h]”hŒ5.4-rc6”…””}”(hj\  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KNhjY  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj?  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjî  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒNovember 10”h]”hŒNovember 10”…””}”(hj|  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KOhjy  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjv  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.4-rc7”h]”hŒ5.4-rc7”…””}”(hj“  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KOhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjv  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjî  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒNovember 17”h]”hŒNovember 17”…””}”(hj³  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KPhj°  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj­  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.4-rc8”h]”hŒ5.4-rc8”…””}”(hjÊ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KPhjÇ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj­  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjî  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒNovember 24”h]”hŒNovember 24”…””}”(hjê  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KQhjç  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjä  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.4 stable release”h]”hŒ5.4 stable release”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KQhjþ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjä  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjî  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jì  hjÓ  ubeh}”(h]”h ]”h"]”h$]”h&]”Œcols”Kuh1jÑ  hjÎ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÌ  hjÈ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´KGhhéh²hubhÚ)”}”(hX½  How do the developers decide when to close the development cycle and create
the stable release?  The most significant metric used is the list of
regressions from previous releases.  No bugs are welcome, but those which
break systems which worked in the past are considered to be especially
serious.  For this reason, patches which cause regressions are looked upon
unfavorably and are quite likely to be reverted during the stabilization
period.”h]”hX½  How do the developers decide when to close the development cycle and create
the stable release?  The most significant metric used is the list of
regressions from previous releases.  No bugs are welcome, but those which
break systems which worked in the past are considered to be especially
serious.  For this reason, patches which cause regressions are looked upon
unfavorably and are quite likely to be reverted during the stabilization
period.”…””}”(hj4  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KThhéh²hubhÚ)”}”(hX  The developers' goal is to fix all known regressions before the stable
release is made.  In the real world, this kind of perfection is hard to
achieve; there are just too many variables in a project of this size.
There comes a point where delaying the final release just makes the problem
worse; the pile of changes waiting for the next merge window will grow
larger, creating even more regressions the next time around.  So most kernels
go out with a handful of known regressions, though, hopefully, none of them
are serious.”h]”hX  The developersâ€™ goal is to fix all known regressions before the stable
release is made.  In the real world, this kind of perfection is hard to
achieve; there are just too many variables in a project of this size.
There comes a point where delaying the final release just makes the problem
worse; the pile of changes waiting for the next merge window will grow
larger, creating even more regressions the next time around.  So most kernels
go out with a handful of known regressions, though, hopefully, none of them
are serious.”…””}”(hjB  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K\hhéh²hubhÚ)”}”(hŒüOnce a stable release is made, its ongoing maintenance is passed off to the
"stable team," currently consists of Greg Kroah-Hartman and Sasha Levin. The
stable team will release occasional updates to the stable release using the
9.x.y numbering scheme.”h]”hX   Once a stable release is made, its ongoing maintenance is passed off to the
â€œstable team,â€ currently consists of Greg Kroah-Hartman and Sasha Levin. The
stable team will release occasional updates to the stable release using the
9.x.y numbering scheme.”…””}”(hjP  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kehhéh²hubhÚ)”}”(hXc  To be considered for an update release, a patch must (1) fix a significant
bug, and (2) already be merged into the mainline for the next development
kernel. Kernels will typically receive stable updates for a little more
than one development cycle past their initial release. So, for example, the
5.2 kernel's history looked like this (all dates in 2019):”h]”hXe  To be considered for an update release, a patch must (1) fix a significant
bug, and (2) already be merged into the mainline for the next development
kernel. Kernels will typically receive stable updates for a little more
than one development cycle past their initial release. So, for example, the
5.2 kernelâ€™s history looked like this (all dates in 2019):”…””}”(hj^  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kjhhéh²hubjÇ  )”}”(hX  ==============  ===============================
July 7          5.2 stable release
July 14         5.2.1
July 21         5.2.2
July 26         5.2.3
July 28         5.2.4
July 31         5.2.5
...             ...
October 11      5.2.21
==============  ===============================
”h]”jÍ  )”}”(hhh]”jÒ  )”}”(hhh]”(j×  )”}”(hhh]”h}”(h]”h ]”h"]”h$]”h&]”Œcolwidth”Kuh1jÖ  hjs  ubj×  )”}”(hhh]”h}”(h]”h ]”h"]”h$]”h&]”Œcolwidth”Kuh1jÖ  hjs  ubjí  )”}”(hhh]”(jò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒJuly 7”h]”hŒJuly 7”…””}”(hj“  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kqhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.2 stable release”h]”hŒ5.2 stable release”…””}”(hjª  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kqhj§  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjŠ  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒJuly 14”h]”hŒJuly 14”…””}”(hjÊ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KrhjÇ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjÄ  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.2.1”h]”hŒ5.2.1”…””}”(hjá  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KrhjÞ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjÄ  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjŠ  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒJuly 21”h]”hŒJuly 21”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kshjþ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjû  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.2.2”h]”hŒ5.2.2”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kshj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjû  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjŠ  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒJuly 26”h]”hŒJuly 26”…””}”(hj8  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kthj5  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj2  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.2.3”h]”hŒ5.2.3”…””}”(hjO  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KthjL  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj2  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjŠ  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒJuly 28”h]”hŒJuly 28”…””}”(hjo  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kuhjl  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hji  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.2.4”h]”hŒ5.2.4”…””}”(hj†  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kuhjƒ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hji  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjŠ  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒJuly 31”h]”hŒJuly 31”…””}”(hj¦  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kvhj£  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj   ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.2.5”h]”hŒ5.2.5”…””}”(hj½  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kvhjº  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj   ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjŠ  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒ...”h]”hŒ...”…””}”(hjÝ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KwhjÚ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj×  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ...”h]”hŒ...”…””}”(hjô  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kwhjñ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj×  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjŠ  ubjò  )”}”(hhh]”(j÷  )”}”(hhh]”hÚ)”}”(hŒ
October 11”h]”hŒ
October 11”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kxhj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj  ubj÷  )”}”(hhh]”hÚ)”}”(hŒ5.2.21”h]”hŒ5.2.21”…””}”(hj+  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kxhj(  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jñ  hjŠ  ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jì  hjs  ubeh}”(h]”h ]”h"]”h$]”h&]”Œcols”Kuh1jÑ  hjp  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÌ  hjl  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´Kphhéh²hubhÚ)”}”(hŒ65.2.21 was the final stable update of the 5.2 release.”h]”hŒ65.2.21 was the final stable update of the 5.2 release.”…””}”(hj^  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K{hhéh²hubhÚ)”}”(hŒËSome kernels are designated "long term" kernels; they will receive support
for a longer period.  Please refer to the following link for the list of active
long term kernel versions and their maintainers:”h]”hŒÏSome kernels are designated â€œlong termâ€ kernels; they will receive support
for a longer period.  Please refer to the following link for the list of active
long term kernel versions and their maintainers:”…””}”(hjl  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K}hhéh²hubjÇ  )”}”(hŒ.https://www.kernel.org/category/releases.html
”h]”hÚ)”}”(hŒ-https://www.kernel.org/category/releases.html”h]”j  )”}”(hj€  h]”hŒ-https://www.kernel.org/category/releases.html”…””}”(hj‚  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”j€  uh1j  hj~  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Khjz  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´Khhéh²hubhÚ)”}”(hŒÜThe selection of a kernel for long-term support is purely a matter of a
maintainer having the need and the time to maintain that release.  There
are no known plans for long-term support for any specific upcoming
release.”h]”hŒÜThe selection of a kernel for long-term support is purely a matter of a
maintainer having the need and the time to maintain that release.  There
are no known plans for long-term support for any specific upcoming
release.”…””}”(hjœ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kƒhhéh²hubeh}”(h]”Œthe-big-picture”ah ]”h"]”Œthe big picture”ah$]”h&]”uh1hÄhhÆh²hh³hÃh´KubhÅ)”}”(hhh]”(hÊ)”}”(hŒThe lifecycle of a patch”h]”hŒThe lifecycle of a patch”…””}”(hjµ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhj²  h²hh³hÃh´KŠubhÚ)”}”(hX  Patches do not go directly from the developer's keyboard into the mainline
kernel.  There is, instead, a somewhat involved (if somewhat informal)
process designed to ensure that each patch is reviewed for quality and that
each patch implements a change which is desirable to have in the mainline.
This process can happen quickly for minor fixes, or, in the case of large
and controversial changes, go on for years.  Much developer frustration
comes from a lack of understanding of this process or from attempts to
circumvent it.”h]”hX  Patches do not go directly from the developerâ€™s keyboard into the mainline
kernel.  There is, instead, a somewhat involved (if somewhat informal)
process designed to ensure that each patch is reviewed for quality and that
each patch implements a change which is desirable to have in the mainline.
This process can happen quickly for minor fixes, or, in the case of large
and controversial changes, go on for years.  Much developer frustration
comes from a lack of understanding of this process or from attempts to
circumvent it.”…””}”(hjÃ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KŒhj²  h²hubhÚ)”}”(hX  In the hopes of reducing that frustration, this document will describe how
a patch gets into the kernel.  What follows below is an introduction which
describes the process in a somewhat idealized way.  A much more detailed
treatment will come in later sections.”h]”hX  In the hopes of reducing that frustration, this document will describe how
a patch gets into the kernel.  What follows below is an introduction which
describes the process in a somewhat idealized way.  A much more detailed
treatment will come in later sections.”…””}”(hjÑ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K•hj²  h²hubhÚ)”}”(hŒ4The stages that a patch goes through are, generally:”h]”hŒ4The stages that a patch goes through are, generally:”…””}”(hjß  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kšhj²  h²hubjÇ  )”}”(hX2  - Design.  This is where the real requirements for the patch - and the way
  those requirements will be met - are laid out.  Design work is often
  done without involving the community, but it is better to do this work
  in the open if at all possible; it can save a lot of time redesigning
  things later.

- Early review.  Patches are posted to the relevant mailing list, and
  developers on that list reply with any comments they may have.  This
  process should turn up any major problems with a patch if all goes
  well.

- Wider review.  When the patch is getting close to ready for mainline
  inclusion, it should be accepted by a relevant subsystem maintainer -
  though this acceptance is not a guarantee that the patch will make it
  all the way to the mainline.  The patch will show up in the maintainer's
  subsystem tree and into the -next trees (described below).  When the
  process works, this step leads to more extensive review of the patch and
  the discovery of any problems resulting from the integration of this
  patch with work being done by others.
”h]”hŒbullet_list”“”)”}”(hhh]”(hŒ	list_item”“”)”}”(hX)  Design.  This is where the real requirements for the patch - and the way
those requirements will be met - are laid out.  Design work is often
done without involving the community, but it is better to do this work
in the open if at all possible; it can save a lot of time redesigning
things later.
”h]”hÚ)”}”(hX(  Design.  This is where the real requirements for the patch - and the way
those requirements will be met - are laid out.  Design work is often
done without involving the community, but it is better to do this work
in the open if at all possible; it can save a lot of time redesigning
things later.”h]”hX(  Design.  This is where the real requirements for the patch - and the way
those requirements will be met - are laid out.  Design work is often
done without involving the community, but it is better to do this work
in the open if at all possible; it can save a lot of time redesigning
things later.”…””}”(hjü  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kœhjø  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjó  ubj÷  )”}”(hŒÒEarly review.  Patches are posted to the relevant mailing list, and
developers on that list reply with any comments they may have.  This
process should turn up any major problems with a patch if all goes
well.
”h]”hÚ)”}”(hŒÑEarly review.  Patches are posted to the relevant mailing list, and
developers on that list reply with any comments they may have.  This
process should turn up any major problems with a patch if all goes
well.”h]”hŒÑEarly review.  Patches are posted to the relevant mailing list, and
developers on that list reply with any comments they may have.  This
process should turn up any major problems with a patch if all goes
well.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K¢hj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjó  ubj÷  )”}”(hX  Wider review.  When the patch is getting close to ready for mainline
inclusion, it should be accepted by a relevant subsystem maintainer -
though this acceptance is not a guarantee that the patch will make it
all the way to the mainline.  The patch will show up in the maintainer's
subsystem tree and into the -next trees (described below).  When the
process works, this step leads to more extensive review of the patch and
the discovery of any problems resulting from the integration of this
patch with work being done by others.
”h]”hÚ)”}”(hX  Wider review.  When the patch is getting close to ready for mainline
inclusion, it should be accepted by a relevant subsystem maintainer -
though this acceptance is not a guarantee that the patch will make it
all the way to the mainline.  The patch will show up in the maintainer's
subsystem tree and into the -next trees (described below).  When the
process works, this step leads to more extensive review of the patch and
the discovery of any problems resulting from the integration of this
patch with work being done by others.”h]”hX  Wider review.  When the patch is getting close to ready for mainline
inclusion, it should be accepted by a relevant subsystem maintainer -
though this acceptance is not a guarantee that the patch will make it
all the way to the mainline.  The patch will show up in the maintainerâ€™s
subsystem tree and into the -next trees (described below).  When the
process works, this step leads to more extensive review of the patch and
the discovery of any problems resulting from the integration of this
patch with work being done by others.”…””}”(hj,  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K§hj(  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjó  ubeh}”(h]”h ]”h"]”h$]”h&]”Œbullet”Œ-”uh1jñ  h³hÃh´Kœhjí  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´Kœhj²  h²hubjò  )”}”(hhh]”j÷  )”}”(hXý  Please note that most maintainers also have day jobs, so merging
your patch may not be their highest priority.  If your patch is
getting feedback about changes that are needed, you should either
make those changes or justify why they should not be made.  If your
patch has no review complaints but is not being merged by its
appropriate subsystem or driver maintainer, you should be persistent
in updating the patch to the current kernel so that it applies cleanly
and keep sending it for review and merging.
”h]”hÚ)”}”(hXü  Please note that most maintainers also have day jobs, so merging
your patch may not be their highest priority.  If your patch is
getting feedback about changes that are needed, you should either
make those changes or justify why they should not be made.  If your
patch has no review complaints but is not being merged by its
appropriate subsystem or driver maintainer, you should be persistent
in updating the patch to the current kernel so that it applies cleanly
and keep sending it for review and merging.”h]”hXü  Please note that most maintainers also have day jobs, so merging
your patch may not be their highest priority.  If your patch is
getting feedback about changes that are needed, you should either
make those changes or justify why they should not be made.  If your
patch has no review complaints but is not being merged by its
appropriate subsystem or driver maintainer, you should be persistent
in updating the patch to the current kernel so that it applies cleanly
and keep sending it for review and merging.”…””}”(hjU  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K°hjQ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjN  h²hh³hÃh´Nubah}”(h]”h ]”h"]”h$]”h&]”jF  jG  uh1jñ  h³hÃh´K°hj²  h²hubjÇ  )”}”(hX`  - Merging into the mainline.  Eventually, a successful patch will be
  merged into the mainline repository managed by Linus Torvalds.  More
  comments and/or problems may surface at this time; it is important that
  the developer be responsive to these and fix any issues which arise.

- Stable release.  The number of users potentially affected by the patch
  is now large, so, once again, new problems may arise.

- Long-term maintenance.  While it is certainly possible for a developer
  to forget about code after merging it, that sort of behavior tends to
  leave a poor impression in the development community.  Merging code
  eliminates some of the maintenance burden, in that others will fix
  problems caused by API changes.  But the original developer should
  continue to take responsibility for the code if it is to remain useful
  in the longer term.
”h]”jò  )”}”(hhh]”(j÷  )”}”(hX  Merging into the mainline.  Eventually, a successful patch will be
merged into the mainline repository managed by Linus Torvalds.  More
comments and/or problems may surface at this time; it is important that
the developer be responsive to these and fix any issues which arise.
”h]”hÚ)”}”(hX  Merging into the mainline.  Eventually, a successful patch will be
merged into the mainline repository managed by Linus Torvalds.  More
comments and/or problems may surface at this time; it is important that
the developer be responsive to these and fix any issues which arise.”h]”hX  Merging into the mainline.  Eventually, a successful patch will be
merged into the mainline repository managed by Linus Torvalds.  More
comments and/or problems may surface at this time; it is important that
the developer be responsive to these and fix any issues which arise.”…””}”(hjz  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K¹hjv  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjs  ubj÷  )”}”(hŒ}Stable release.  The number of users potentially affected by the patch
is now large, so, once again, new problems may arise.
”h]”hÚ)”}”(hŒ|Stable release.  The number of users potentially affected by the patch
is now large, so, once again, new problems may arise.”h]”hŒ|Stable release.  The number of users potentially affected by the patch
is now large, so, once again, new problems may arise.”…””}”(hj’  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´K¾hjŽ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjs  ubj÷  )”}”(hX²  Long-term maintenance.  While it is certainly possible for a developer
to forget about code after merging it, that sort of behavior tends to
leave a poor impression in the development community.  Merging code
eliminates some of the maintenance burden, in that others will fix
problems caused by API changes.  But the original developer should
continue to take responsibility for the code if it is to remain useful
in the longer term.
”h]”hÚ)”}”(hX±  Long-term maintenance.  While it is certainly possible for a developer
to forget about code after merging it, that sort of behavior tends to
leave a poor impression in the development community.  Merging code
eliminates some of the maintenance burden, in that others will fix
problems caused by API changes.  But the original developer should
continue to take responsibility for the code if it is to remain useful
in the longer term.”h]”hX±  Long-term maintenance.  While it is certainly possible for a developer
to forget about code after merging it, that sort of behavior tends to
leave a poor impression in the development community.  Merging code
eliminates some of the maintenance burden, in that others will fix
problems caused by API changes.  But the original developer should
continue to take responsibility for the code if it is to remain useful
in the longer term.”…””}”(hjª  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KÁhj¦  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hjs  ubeh}”(h]”h ]”h"]”h$]”h&]”jF  jG  uh1jñ  h³hÃh´K¹hjo  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´K¹hj²  h²hubhÚ)”}”(hŒáOne of the largest mistakes made by kernel developers (or their employers)
is to try to cut the process down to a single "merging into the mainline"
step.  This approach invariably leads to frustration for everybody
involved.”h]”hŒåOne of the largest mistakes made by kernel developers (or their employers)
is to try to cut the process down to a single â€œmerging into the mainlineâ€
step.  This approach invariably leads to frustration for everybody
involved.”…””}”(hjÊ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KÉhj²  h²hubeh}”(h]”Œthe-lifecycle-of-a-patch”ah ]”h"]”Œthe lifecycle of a patch”ah$]”h&]”uh1hÄhhÆh²hh³hÃh´KŠubhÅ)”}”(hhh]”(hÊ)”}”(hŒHow patches get into the Kernel”h]”hŒHow patches get into the Kernel”…””}”(hjã  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhjà  h²hh³hÃh´KÏubhÚ)”}”(hXû  There is exactly one person who can merge patches into the mainline kernel
repository: Linus Torvalds. But, for example, of the over 9,500 patches
which went into the 2.6.38 kernel, only 112 (around 1.3%) were directly
chosen by Linus himself. The kernel project has long since grown to a size
where no single developer could possibly inspect and select every patch
unassisted. The way the kernel developers have addressed this growth is
through the use of a lieutenant system built around a chain of trust.”h]”hXû  There is exactly one person who can merge patches into the mainline kernel
repository: Linus Torvalds. But, for example, of the over 9,500 patches
which went into the 2.6.38 kernel, only 112 (around 1.3%) were directly
chosen by Linus himself. The kernel project has long since grown to a size
where no single developer could possibly inspect and select every patch
unassisted. The way the kernel developers have addressed this growth is
through the use of a lieutenant system built around a chain of trust.”…””}”(hjñ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KÑhjà  h²hubhÚ)”}”(hXà  The kernel code base is logically broken down into a set of subsystems:
networking, specific architecture support, memory management, video
devices, etc.  Most subsystems have a designated maintainer, a developer
who has overall responsibility for the code within that subsystem.  These
subsystem maintainers are the gatekeepers (in a loose way) for the portion
of the kernel they manage; they are the ones who will (usually) accept a
patch for inclusion into the mainline kernel.”h]”hXà  The kernel code base is logically broken down into a set of subsystems:
networking, specific architecture support, memory management, video
devices, etc.  Most subsystems have a designated maintainer, a developer
who has overall responsibility for the code within that subsystem.  These
subsystem maintainers are the gatekeepers (in a loose way) for the portion
of the kernel they manage; they are the ones who will (usually) accept a
patch for inclusion into the mainline kernel.”…””}”(hjÿ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´KÙhjà  h²hubhÚ)”}”(hX¬  Subsystem maintainers each manage their own version of the kernel source
tree, usually (but certainly not always) using the git source management
tool.  Tools like git (and related tools like quilt or mercurial) allow
maintainers to track a list of patches, including authorship information
and other metadata.  At any given time, the maintainer can identify which
patches in his or her repository are not found in the mainline.”h]”hX¬  Subsystem maintainers each manage their own version of the kernel source
tree, usually (but certainly not always) using the git source management
tool.  Tools like git (and related tools like quilt or mercurial) allow
maintainers to track a list of patches, including authorship information
and other metadata.  At any given time, the maintainer can identify which
patches in his or her repository are not found in the mainline.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Káhjà  h²hubhÚ)”}”(hXù  When the merge window opens, top-level maintainers will ask Linus to "pull"
the patches they have selected for merging from their repositories.  If
Linus agrees, the stream of patches will flow up into his repository,
becoming part of the mainline kernel.  The amount of attention that Linus
pays to specific patches received in a pull operation varies.  It is clear
that, sometimes, he looks quite closely.  But, as a general rule, Linus
trusts the subsystem maintainers to not send bad patches upstream.”h]”hXý  When the merge window opens, top-level maintainers will ask Linus to â€œpullâ€
the patches they have selected for merging from their repositories.  If
Linus agrees, the stream of patches will flow up into his repository,
becoming part of the mainline kernel.  The amount of attention that Linus
pays to specific patches received in a pull operation varies.  It is clear
that, sometimes, he looks quite closely.  But, as a general rule, Linus
trusts the subsystem maintainers to not send bad patches upstream.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kèhjà  h²hubhÚ)”}”(hX½  Subsystem maintainers, in turn, can pull patches from other maintainers.
For example, the networking tree is built from patches which accumulated
first in trees dedicated to network device drivers, wireless networking,
etc.  This chain of repositories can be arbitrarily long, though it rarely
exceeds two or three links.  Since each maintainer in the chain trusts
those managing lower-level trees, this process is known as the "chain of
trust."”h]”hXÁ  Subsystem maintainers, in turn, can pull patches from other maintainers.
For example, the networking tree is built from patches which accumulated
first in trees dedicated to network device drivers, wireless networking,
etc.  This chain of repositories can be arbitrarily long, though it rarely
exceeds two or three links.  Since each maintainer in the chain trusts
those managing lower-level trees, this process is known as the â€œchain of
trust.â€”…””}”(hj)  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Kðhjà  h²hubhÚ)”}”(hŒ°Clearly, in a system like this, getting patches into the kernel depends on
finding the right maintainer.  Sending patches directly to Linus is not
normally the right way to go.”h]”hŒ°Clearly, in a system like this, getting patches into the kernel depends on
finding the right maintainer.  Sending patches directly to Linus is not
normally the right way to go.”…””}”(hj7  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Køhjà  h²hubeh}”(h]”Œhow-patches-get-into-the-kernel”ah ]”h"]”Œhow patches get into the kernel”ah$]”h&]”uh1hÄhhÆh²hh³hÃh´KÏubhÅ)”}”(hhh]”(hÊ)”}”(hŒ
Next trees”h]”hŒ
Next trees”…””}”(hjP  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhjM  h²hh³hÃh´KþubhÚ)”}”(hXß  The chain of subsystem trees guides the flow of patches into the kernel,
but it also raises an interesting question: what if somebody wants to look
at all of the patches which are being prepared for the next merge window?
Developers will be interested in what other changes are pending to see
whether there are any conflicts to worry about; a patch which changes a
core kernel function prototype, for example, will conflict with any other
patches which use the older form of that function.  Reviewers and testers
want access to the changes in their integrated form before all of those
changes land in the mainline kernel.  One could pull changes from all of
the interesting subsystem trees, but that would be a big and error-prone
job.”h]”hXß  The chain of subsystem trees guides the flow of patches into the kernel,
but it also raises an interesting question: what if somebody wants to look
at all of the patches which are being prepared for the next merge window?
Developers will be interested in what other changes are pending to see
whether there are any conflicts to worry about; a patch which changes a
core kernel function prototype, for example, will conflict with any other
patches which use the older form of that function.  Reviewers and testers
want access to the changes in their integrated form before all of those
changes land in the mainline kernel.  One could pull changes from all of
the interesting subsystem trees, but that would be a big and error-prone
job.”…””}”(hj^  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M hjM  h²hubhÚ)”}”(hXf  The answer comes in the form of -next trees, where subsystem trees are
collected for testing and review.  The older of these trees, maintained by
Andrew Morton, is called "-mm" (for memory management, which is how it got
started).  The -mm tree integrates patches from a long list of subsystem
trees; it also has some patches aimed at helping with debugging.”h]”hXj  The answer comes in the form of -next trees, where subsystem trees are
collected for testing and review.  The older of these trees, maintained by
Andrew Morton, is called â€œ-mmâ€ (for memory management, which is how it got
started).  The -mm tree integrates patches from a long list of subsystem
trees; it also has some patches aimed at helping with debugging.”…””}”(hjl  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MhjM  h²hubhÚ)”}”(hX§  Beyond that, -mm contains a significant collection of patches which have
been selected by Andrew directly.  These patches may have been posted on a
mailing list, or they may apply to a part of the kernel for which there is
no designated subsystem tree.  As a result, -mm operates as a sort of
subsystem tree of last resort; if there is no other obvious path for a
patch into the mainline, it is likely to end up in -mm.  Miscellaneous
patches which accumulate in -mm will eventually either be forwarded on to
an appropriate subsystem tree or be sent directly to Linus.  In a typical
development cycle, approximately 5-10% of the patches going into the
mainline get there via -mm.”h]”hX§  Beyond that, -mm contains a significant collection of patches which have
been selected by Andrew directly.  These patches may have been posted on a
mailing list, or they may apply to a part of the kernel for which there is
no designated subsystem tree.  As a result, -mm operates as a sort of
subsystem tree of last resort; if there is no other obvious path for a
patch into the mainline, it is likely to end up in -mm.  Miscellaneous
patches which accumulate in -mm will eventually either be forwarded on to
an appropriate subsystem tree or be sent directly to Linus.  In a typical
development cycle, approximately 5-10% of the patches going into the
mainline get there via -mm.”…””}”(hjz  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MhjM  h²hubhÚ)”}”(hŒSThe current -mm patch is available in the "mmotm" (-mm of the moment)
directory at:”h]”hŒWThe current -mm patch is available in the â€œmmotmâ€ (-mm of the moment)
directory at:”…””}”(hjˆ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MhjM  h²hubjÇ  )”}”(hŒ$https://www.ozlabs.org/~akpm/mmotm/
”h]”hÚ)”}”(hŒ#https://www.ozlabs.org/~akpm/mmotm/”h]”j  )”}”(hjœ  h]”hŒ#https://www.ozlabs.org/~akpm/mmotm/”…””}”(hjž  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jœ  uh1j  hjš  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M hj–  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´M hjM  h²hubhÚ)”}”(hŒUse of the MMOTM tree is likely to be a frustrating experience, though;
there is a definite chance that it will not even compile.”h]”hŒUse of the MMOTM tree is likely to be a frustrating experience, though;
there is a definite chance that it will not even compile.”…””}”(hj¸  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M"hjM  h²hubhÚ)”}”(hX]  The primary tree for next-cycle patch merging is linux-next, maintained by
Mark Brown.  The linux-next tree is, by design, a snapshot of what
the mainline is expected to look like after the next merge window closes.
Linux-next trees are announced on the linux-kernel and linux-next mailing
lists when they are assembled; they can be downloaded from:”h]”hX]  The primary tree for next-cycle patch merging is linux-next, maintained by
Mark Brown.  The linux-next tree is, by design, a snapshot of what
the mainline is expected to look like after the next merge window closes.
Linux-next trees are announced on the linux-kernel and linux-next mailing
lists when they are assembled; they can be downloaded from:”…””}”(hjÆ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M%hjM  h²hubjÇ  )”}”(hŒ.https://www.kernel.org/pub/linux/kernel/next/
”h]”hÚ)”}”(hŒ-https://www.kernel.org/pub/linux/kernel/next/”h]”j  )”}”(hjÚ  h]”hŒ-https://www.kernel.org/pub/linux/kernel/next/”…””}”(hjÜ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jÚ  uh1j  hjØ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M+hjÔ  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´M+hjM  h²hubhÚ)”}”(hŒÔLinux-next has become an integral part of the kernel development process;
all patches merged during a given merge window should really have found
their way into linux-next some time before the merge window opens.”h]”hŒÔLinux-next has become an integral part of the kernel development process;
all patches merged during a given merge window should really have found
their way into linux-next some time before the merge window opens.”…””}”(hjö  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M-hjM  h²hubeh}”(h]”Œ
next-trees”ah ]”h"]”Œ
next trees”ah$]”h&]”uh1hÄhhÆh²hh³hÃh´KþubhÅ)”}”(hhh]”(hÊ)”}”(hŒStaging trees”h]”hŒStaging trees”…””}”(hj	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhj	  h²hh³hÃh´M3ubhÚ)”}”(hXÈ  The kernel source tree contains the drivers/staging/ directory, where
many sub-directories for drivers or filesystems that are on their way to
being added to the kernel tree live.  They remain in drivers/staging while
they still need more work; once complete, they can be moved into the
kernel proper.  This is a way to keep track of drivers that aren't
up to Linux kernel coding or quality standards, but people may want to use
them and track development.”h]”hXÊ  The kernel source tree contains the drivers/staging/ directory, where
many sub-directories for drivers or filesystems that are on their way to
being added to the kernel tree live.  They remain in drivers/staging while
they still need more work; once complete, they can be moved into the
kernel proper.  This is a way to keep track of drivers that arenâ€™t
up to Linux kernel coding or quality standards, but people may want to use
them and track development.”…””}”(hj	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M5hj	  h²hubhÚ)”}”(hX  Greg Kroah-Hartman currently maintains the staging tree.  Drivers that
still need work are sent to him, with each driver having its own
subdirectory in drivers/staging/.  Along with the driver source files, a
TODO file should be present in the directory as well.  The TODO file lists
the pending work that the driver needs for acceptance into the kernel
proper, as well as a list of people that should be Cc'd for any patches to
the driver.  Current rules require that drivers contributed to staging
must, at a minimum, compile properly.”h]”hX  Greg Kroah-Hartman currently maintains the staging tree.  Drivers that
still need work are sent to him, with each driver having its own
subdirectory in drivers/staging/.  Along with the driver source files, a
TODO file should be present in the directory as well.  The TODO file lists
the pending work that the driver needs for acceptance into the kernel
proper, as well as a list of people that should be Ccâ€™d for any patches to
the driver.  Current rules require that drivers contributed to staging
must, at a minimum, compile properly.”…””}”(hj+	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M=hj	  h²hubhÚ)”}”(hXÑ  Staging can be a relatively easy way to get new drivers into the mainline
where, with luck, they will come to the attention of other developers and
improve quickly.  Entry into staging is not the end of the story, though;
code in staging which is not seeing regular progress will eventually be
removed.  Distributors also tend to be relatively reluctant to enable
staging drivers.  So staging is, at best, a stop on the way toward becoming
a proper mainline driver.”h]”hXÑ  Staging can be a relatively easy way to get new drivers into the mainline
where, with luck, they will come to the attention of other developers and
improve quickly.  Entry into staging is not the end of the story, though;
code in staging which is not seeing regular progress will eventually be
removed.  Distributors also tend to be relatively reluctant to enable
staging drivers.  So staging is, at best, a stop on the way toward becoming
a proper mainline driver.”…””}”(hj9	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MFhj	  h²hubeh}”(h]”Œstaging-trees”ah ]”h"]”Œstaging trees”ah$]”h&]”uh1hÄhhÆh²hh³hÃh´M3ubhÅ)”}”(hhh]”(hÊ)”}”(hŒTools”h]”hŒTools”…””}”(hjR	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhjO	  h²hh³hÃh´MPubhÚ)”}”(hXq  As can be seen from the above text, the kernel development process depends
heavily on the ability to herd collections of patches in various
directions.  The whole thing would not work anywhere near as well as it
does without suitably powerful tools.  Tutorials on how to use these tools
are well beyond the scope of this document, but there is space for a few
pointers.”h]”hXq  As can be seen from the above text, the kernel development process depends
heavily on the ability to herd collections of patches in various
directions.  The whole thing would not work anywhere near as well as it
does without suitably powerful tools.  Tutorials on how to use these tools
are well beyond the scope of this document, but there is space for a few
pointers.”…””}”(hj`	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MRhjO	  h²hubhÚ)”}”(hXŽ  By far the dominant source code management system used by the kernel
community is git.  Git is one of a number of distributed version control
systems being developed in the free software community.  It is well tuned
for kernel development, in that it performs quite well when dealing with
large repositories and large numbers of patches.  It also has a reputation
for being difficult to learn and use, though it has gotten better over
time.  Some sort of familiarity with git is almost a requirement for kernel
developers; even if they do not use it for their own work, they'll need git
to keep up with what other developers (and the mainline) are doing.”h]”hX  By far the dominant source code management system used by the kernel
community is git.  Git is one of a number of distributed version control
systems being developed in the free software community.  It is well tuned
for kernel development, in that it performs quite well when dealing with
large repositories and large numbers of patches.  It also has a reputation
for being difficult to learn and use, though it has gotten better over
time.  Some sort of familiarity with git is almost a requirement for kernel
developers; even if they do not use it for their own work, theyâ€™ll need git
to keep up with what other developers (and the mainline) are doing.”…””}”(hjn	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MYhjO	  h²hubhÚ)”}”(hŒPGit is now packaged by almost all Linux distributions.  There is a home
page at:”h]”hŒPGit is now packaged by almost all Linux distributions.  There is a home
page at:”…””}”(hj|	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MchjO	  h²hubjÇ  )”}”(hŒhttps://git-scm.com/
”h]”hÚ)”}”(hŒhttps://git-scm.com/”h]”j  )”}”(hj	  h]”hŒhttps://git-scm.com/”…””}”(hj’	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”j	  uh1j  hjŽ	  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MfhjŠ	  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´MfhjO	  h²hubhÚ)”}”(hŒ6That page has pointers to documentation and tutorials.”h]”hŒ6That page has pointers to documentation and tutorials.”…””}”(hj¬	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MhhjO	  h²hubhÚ)”}”(hŒfAmong the kernel developers who do not use git, the most popular choice is
almost certainly Mercurial:”h]”hŒfAmong the kernel developers who do not use git, the most popular choice is
almost certainly Mercurial:”…””}”(hjº	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MjhjO	  h²hubjÇ  )”}”(hŒ#https://www.selenic.com/mercurial/
”h]”hÚ)”}”(hŒ"https://www.selenic.com/mercurial/”h]”j  )”}”(hjÎ	  h]”hŒ"https://www.selenic.com/mercurial/”…””}”(hjÐ	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jÎ	  uh1j  hjÌ	  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MmhjÈ	  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´MmhjO	  h²hubhÚ)”}”(hŒdMercurial shares many features with git, but it provides an interface which
many find easier to use.”h]”hŒdMercurial shares many features with git, but it provides an interface which
many find easier to use.”…””}”(hjê	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MohjO	  h²hubhÚ)”}”(hŒ,The other tool worth knowing about is Quilt:”h]”hŒ,The other tool worth knowing about is Quilt:”…””}”(hjø	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MrhjO	  h²hubjÇ  )”}”(hŒ,https://savannah.nongnu.org/projects/quilt/
”h]”hÚ)”}”(hŒ+https://savannah.nongnu.org/projects/quilt/”h]”j  )”}”(hj
  h]”hŒ+https://savannah.nongnu.org/projects/quilt/”…””}”(hj
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”j
  uh1j  hj

  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Mthj
  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´MthjO	  h²hubhÚ)”}”(hX”  Quilt is a patch management system, rather than a source code management
system.  It does not track history over time; it is, instead, oriented
toward tracking a specific set of changes against an evolving code base.
Some major subsystem maintainers use quilt to manage patches intended to go
upstream.  For the management of certain kinds of trees (-mm, for example),
quilt is the best tool for the job.”h]”hX”  Quilt is a patch management system, rather than a source code management
system.  It does not track history over time; it is, instead, oriented
toward tracking a specific set of changes against an evolving code base.
Some major subsystem maintainers use quilt to manage patches intended to go
upstream.  For the management of certain kinds of trees (-mm, for example),
quilt is the best tool for the job.”…””}”(hj(
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MvhjO	  h²hubeh}”(h]”Œtools”ah ]”h"]”Œtools”ah$]”h&]”uh1hÄhhÆh²hh³hÃh´MPubhÅ)”}”(hhh]”(hÊ)”}”(hŒMailing lists”h]”hŒMailing lists”…””}”(hjA
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhj>
  h²hh³hÃh´MubhÚ)”}”(hX  A great deal of Linux kernel development work is done by way of mailing
lists.  It is hard to be a fully-functioning member of the community
without joining at least one list somewhere.  But Linux mailing lists also
represent a potential hazard to developers, who risk getting buried under a
load of electronic mail, running afoul of the conventions used on the Linux
lists, or both.”h]”hX  A great deal of Linux kernel development work is done by way of mailing
lists.  It is hard to be a fully-functioning member of the community
without joining at least one list somewhere.  But Linux mailing lists also
represent a potential hazard to developers, who risk getting buried under a
load of electronic mail, running afoul of the conventions used on the Linux
lists, or both.”…””}”(hjO
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Mhj>
  h²hubhÚ)”}”(hŒTMost kernel mailing lists are hosted at kernel.org; the master list can
be found at:”h]”hŒTMost kernel mailing lists are hosted at kernel.org; the master list can
be found at:”…””}”(hj]
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Mˆhj>
  h²hubjÇ  )”}”(hŒhttps://subspace.kernel.org
”h]”hÚ)”}”(hŒhttps://subspace.kernel.org”h]”j  )”}”(hjq
  h]”hŒhttps://subspace.kernel.org”…””}”(hjs
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jq
  uh1j  hjo
  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M‹hjk
  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆ  h³hÃh´M‹hj>
  h²hubhÚ)”}”(hŒwThere are lists hosted elsewhere; please check the MAINTAINERS file for
the list relevant for any particular subsystem.”h]”hŒwThere are lists hosted elsewhere; please check the MAINTAINERS file for
the list relevant for any particular subsystem.”…””}”(hj
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Mhj>
  h²hubhÚ)”}”(hXÖ  The core mailing list for kernel development is, of course, linux-kernel.
This list is an intimidating place to be; volume can reach 500 messages per
day, the amount of noise is high, the conversation can be severely
technical, and participants are not always concerned with showing a high
degree of politeness.  But there is no other place where the kernel
development community comes together as a whole; developers who avoid this
list will miss important information.”h]”hXÖ  The core mailing list for kernel development is, of course, linux-kernel.
This list is an intimidating place to be; volume can reach 500 messages per
day, the amount of noise is high, the conversation can be severely
technical, and participants are not always concerned with showing a high
degree of politeness.  But there is no other place where the kernel
development community comes together as a whole; developers who avoid this
list will miss important information.”…””}”(hj›
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Mhj>
  h²hubhÚ)”}”(hŒ@There are a few hints which can help with linux-kernel survival:”h]”hŒ@There are a few hints which can help with linux-kernel survival:”…””}”(hj©
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M˜hj>
  h²hubjò  )”}”(hhh]”(j÷  )”}”(hŒ“Have the list delivered to a separate folder, rather than your main
mailbox.  One must be able to ignore the stream for sustained periods of
time.
”h]”hÚ)”}”(hŒ’Have the list delivered to a separate folder, rather than your main
mailbox.  One must be able to ignore the stream for sustained periods of
time.”h]”hŒ’Have the list delivered to a separate folder, rather than your main
mailbox.  One must be able to ignore the stream for sustained periods of
time.”…””}”(hj¾
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Mšhjº
  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj·
  h²hh³hÃh´Nubj÷  )”}”(hX  Do not try to follow every conversation - nobody else does.  It is
important to filter on both the topic of interest (though note that
long-running conversations can drift away from the original subject
without changing the email subject line) and the people who are
participating.
”h]”hÚ)”}”(hX  Do not try to follow every conversation - nobody else does.  It is
important to filter on both the topic of interest (though note that
long-running conversations can drift away from the original subject
without changing the email subject line) and the people who are
participating.”h]”hX  Do not try to follow every conversation - nobody else does.  It is
important to filter on both the topic of interest (though note that
long-running conversations can drift away from the original subject
without changing the email subject line) and the people who are
participating.”…””•ï:      }”(hjÖ
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MžhjÒ
  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj·
  h²hh³hÃh´Nubj÷  )”}”(hŒZDo not feed the trolls.  If somebody is trying to stir up an angry
response, ignore them.
”h]”hÚ)”}”(hŒYDo not feed the trolls.  If somebody is trying to stir up an angry
response, ignore them.”h]”hŒYDo not feed the trolls.  If somebody is trying to stir up an angry
response, ignore them.”…””}”(hjî
  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M¤hjê
  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj·
  h²hh³hÃh´Nubj÷  )”}”(hX‚  When responding to linux-kernel email (or that on other lists) preserve
the Cc: header for all involved.  In the absence of a strong reason (such
as an explicit request), you should never remove recipients.  Always make
sure that the person you are responding to is in the Cc: list.  This
convention also makes it unnecessary to explicitly ask to be copied on
replies to your postings.
”h]”hÚ)”}”(hX  When responding to linux-kernel email (or that on other lists) preserve
the Cc: header for all involved.  In the absence of a strong reason (such
as an explicit request), you should never remove recipients.  Always make
sure that the person you are responding to is in the Cc: list.  This
convention also makes it unnecessary to explicitly ask to be copied on
replies to your postings.”h]”hX  When responding to linux-kernel email (or that on other lists) preserve
the Cc: header for all involved.  In the absence of a strong reason (such
as an explicit request), you should never remove recipients.  Always make
sure that the person you are responding to is in the Cc: list.  This
convention also makes it unnecessary to explicitly ask to be copied on
replies to your postings.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M§hj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj·
  h²hh³hÃh´Nubj÷  )”}”(hŒ¤Search the list archives (and the net as a whole) before asking
questions.  Some developers can get impatient with people who clearly
have not done their homework.
”h]”hÚ)”}”(hŒ£Search the list archives (and the net as a whole) before asking
questions.  Some developers can get impatient with people who clearly
have not done their homework.”h]”hŒ£Search the list archives (and the net as a whole) before asking
questions.  Some developers can get impatient with people who clearly
have not done their homework.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M®hj  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj·
  h²hh³hÃh´Nubj÷  )”}”(hX  Use interleaved ("inline") replies, which makes your response easier to
read. (i.e. avoid top-posting -- the practice of putting your answer above
the quoted text you are responding to.) For more details, see
:ref:`Documentation/process/submitting-patches.rst <interleaved_replies>`.
”h]”hÚ)”}”(hX  Use interleaved ("inline") replies, which makes your response easier to
read. (i.e. avoid top-posting -- the practice of putting your answer above
the quoted text you are responding to.) For more details, see
:ref:`Documentation/process/submitting-patches.rst <interleaved_replies>`.”h]”(hŒÕUse interleaved (â€œinlineâ€) replies, which makes your response easier to
read. (i.e. avoid top-posting -- the practice of putting your answer above
the quoted text you are responding to.) For more details, see
”…””}”(hj6  h²hh³Nh´Nubh)”}”(hŒI:ref:`Documentation/process/submitting-patches.rst <interleaved_replies>`”h]”hŒinline”“”)”}”(hj@  h]”hŒ,Documentation/process/submitting-patches.rst”…””}”(hjD  h²hh³Nh´Nubah}”(h]”h ]”(Œxref”Œstd”Œstd-ref”eh"]”h$]”h&]”uh1jB  hj>  ubah}”(h]”h ]”h"]”h$]”h&]”Œrefdoc”j  Œ	refdomain”jO  Œreftype”Œref”Œrefexplicit”ˆŒrefwarn”ˆŒ	reftarget”Œinterleaved_replies”uh1hh³hÃh´M²hj6  ubhŒ.”…””}”(hj6  h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M²hj2  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj·
  h²hh³hÃh´Nubj÷  )”}”(hŒ–Ask on the correct mailing list.  Linux-kernel may be the general meeting
point, but it is not the best place to find developers from all
subsystems.
”h]”hÚ)”}”(hŒ•Ask on the correct mailing list.  Linux-kernel may be the general meeting
point, but it is not the best place to find developers from all
subsystems.”h]”hŒ•Ask on the correct mailing list.  Linux-kernel may be the general meeting
point, but it is not the best place to find developers from all
subsystems.”…””}”(hjv  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M·hjr  ubah}”(h]”h ]”h"]”h$]”h&]”uh1jö  hj·
  h²hh³hÃh´Nubeh}”(h]”h ]”h"]”h$]”h&]”jF  jG  uh1jñ  h³hÃh´Mšhj>
  h²hubhÚ)”}”(hXõ  The last point - finding the correct mailing list - is a common place for
beginning developers to go wrong.  Somebody who asks a networking-related
question on linux-kernel will almost certainly receive a polite suggestion
to ask on the netdev list instead, as that is the list frequented by most
networking developers.  Other lists exist for the SCSI, video4linux, IDE,
filesystem, etc. subsystems.  The best place to look for mailing lists is
in the MAINTAINERS file packaged with the kernel source.”h]”hXõ  The last point - finding the correct mailing list - is a common place for
beginning developers to go wrong.  Somebody who asks a networking-related
question on linux-kernel will almost certainly receive a polite suggestion
to ask on the netdev list instead, as that is the list frequented by most
networking developers.  Other lists exist for the SCSI, video4linux, IDE,
filesystem, etc. subsystems.  The best place to look for mailing lists is
in the MAINTAINERS file packaged with the kernel source.”…””}”(hj  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´M»hj>
  h²hubeh}”(h]”Œmailing-lists”ah ]”h"]”Œmailing lists”ah$]”h&]”uh1hÄhhÆh²hh³hÃh´MubhÅ)”}”(hhh]”(hÊ)”}”(hŒ'Getting started with Kernel development”h]”hŒ'Getting started with Kernel development”…””}”(hj©  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÉhj¦  h²hh³hÃh´MÅubhÚ)”}”(hŒÜQuestions about how to get started with the kernel development process are
common - from both individuals and companies.  Equally common are missteps
which make the beginning of the relationship harder than it has to be.”h]”hŒÜQuestions about how to get started with the kernel development process are
common - from both individuals and companies.  Equally common are missteps
which make the beginning of the relationship harder than it has to be.”…””}”(hj·  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MÇhj¦  h²hubhÚ)”}”(hXL  Companies often look to hire well-known developers to get a development
group started.  This can, in fact, be an effective technique.  But it also
tends to be expensive and does not do much to grow the pool of experienced
kernel developers.  It is possible to bring in-house developers up to speed
on Linux kernel development, given the investment of a bit of time.  Taking
this time can endow an employer with a group of developers who understand
the kernel and the company both, and who can help to train others as well.
Over the medium term, this is often the more profitable approach.”h]”hXL  Companies often look to hire well-known developers to get a development
group started.  This can, in fact, be an effective technique.  But it also
tends to be expensive and does not do much to grow the pool of experienced
kernel developers.  It is possible to bring in-house developers up to speed
on Linux kernel development, given the investment of a bit of time.  Taking
this time can endow an employer with a group of developers who understand
the kernel and the company both, and who can help to train others as well.
Over the medium term, this is often the more profitable approach.”…””}”(hjÅ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MËhj¦  h²hubhÚ)”}”(hXi  Individual developers are often, understandably, at a loss for a place to
start.  Beginning with a large project can be intimidating; one often wants
to test the waters with something smaller first.  This is the point where
some developers jump into the creation of patches fixing spelling errors or
minor coding style issues.  Unfortunately, such patches create a level of
noise which is distracting for the development community as a whole, so,
increasingly, they are looked down upon.  New developers wishing to
introduce themselves to the community will not get the sort of reception
they wish for by these means.”h]”hXi  Individual developers are often, understandably, at a loss for a place to
start.  Beginning with a large project can be intimidating; one often wants
to test the waters with something smaller first.  This is the point where
some developers jump into the creation of patches fixing spelling errors or
minor coding style issues.  Unfortunately, such patches create a level of
noise which is distracting for the development community as a whole, so,
increasingly, they are looked down upon.  New developers wishing to
introduce themselves to the community will not get the sort of reception
they wish for by these means.”…””}”(hjÓ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MÔhj¦  h²hubhÚ)”}”(hŒ>Andrew Morton gives this advice for aspiring kernel developers”h]”hŒ>Andrew Morton gives this advice for aspiring kernel developers”…””}”(hjá  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´MÞhj¦  h²hubhŒliteral_block”“”)”}”(hXD  The #1 project for all kernel beginners should surely be "make sure
that the kernel runs perfectly at all times on all machines which
you can lay your hands on".  Usually the way to do this is to work
with others on getting things fixed up (this can require
persistence!) but that's fine - it's a part of kernel development.”h]”hXD  The #1 project for all kernel beginners should surely be "make sure
that the kernel runs perfectly at all times on all machines which
you can lay your hands on".  Usually the way to do this is to work
with others on getting things fixed up (this can require
persistence!) but that's fine - it's a part of kernel development.”…””}”hjñ  sbah}”(h]”h ]”h"]”h$]”h&]”Œ	xml:space”Œpreserve”uh1jï  h³hÃh´Mâhj¦  h²hubhÚ)”}”(hŒ#(https://lwn.net/Articles/283982/).”h]”(hŒ(”…””}”(hj  h²hh³Nh´Nubj  )”}”(hŒ https://lwn.net/Articles/283982/”h]”hŒ https://lwn.net/Articles/283982/”…””}”(hj	  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”j  uh1j  hj  ubhŒ).”…””}”(hj  h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Mèhj¦  h²hubhÚ)”}”(hXd  In the absence of obvious problems to fix, developers are advised to look
at the current lists of regressions and open bugs in general.  There is
never any shortage of issues in need of fixing; by addressing these issues,
developers will gain experience with the process while, at the same time,
building respect with the rest of the development community.”h]”hXd  In the absence of obvious problems to fix, developers are advised to look
at the current lists of regressions and open bugs in general.  There is
never any shortage of issues in need of fixing; by addressing these issues,
developers will gain experience with the process while, at the same time,
building respect with the rest of the development community.”…””}”(hj"  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙh³hÃh´Mêhj¦  h²hubeh}”(h]”Œ'getting-started-with-kernel-development”ah ]”h"]”Œ'getting started with kernel development”ah$]”h&]”uh1hÄhhÆh²hh³hÃh´MÅubeh}”(h]”(Œ!how-the-development-process-works”hÂeh ]”h"]”(Œ!how the development process works”Œdevelopment_process”eh$]”h&]”uh1hÄhhh²hh³hÃh´KŒexpect_referenced_by_name”}”j>  h·sŒexpect_referenced_by_id”}”hÂh·subeh}”(h]”h ]”h"]”h$]”h&]”Œsource”hÃuh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(hÉNŒ	generator”NŒ	datestamp”NŒsource_link”NŒ
source_url”NŒtoc_backlinks”jö  Œfootnote_backlinks”KŒsectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒstrip_classes”NŒreport_level”KŒ
halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ	traceback”ˆŒinput_encoding”Œ	utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jg  Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œlanguage_code”Œen”Œrecord_dependencies”NŒconfig”NŒ	id_prefix”hŒauto_id_prefix”Œid”Œdump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”hÃŒ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ	tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œdocinfo_xform”KŒsectsubtitle_xform”‰Œimage_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œ1”]”j  asŒrefids”}”hÂ]”h·asŒnameids”}”(j>  hÂj=  j:  j¯  j¬  j8  j5  jo  j  jÝ  jÚ  jJ  jG  j		  j	  jL	  jI	  j;
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  j2  j¦  uŒfootnote_refs”}”j§  ]”j  asŒcitation_refs”}”Œautofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ	footnotes”]”jI  aŒ	citations”]”Œautofootnote_start”KŒsymbol_footnote_start”K Œ
id_counter”Œcollections”ŒCounter”“”}”ju  Ks…”R”Œparse_messages”]”(hŒsystem_message”“”)”}”(hhh]”hÚ)”}”(hŒeUnexpected possible title overline or transition.
Treating it as ordinary text because it's so short.”h]”hŒgUnexpected possible title overline or transition.
Treating it as ordinary text because itâ€™s so short.”…””}”(hjÒ  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙhjÏ  ubah}”(h]”h ]”h"]”h$]”h&]”Œlevel”KŒtype”ŒINFO”Œline”KxŒsource”hÃuh1jÍ  hjÚ  ubjÎ  )”}”(hhh]”hÚ)”}”(hŒeUnexpected possible title overline or transition.
Treating it as ordinary text because it's so short.”h]”hŒgUnexpected possible title overline or transition.
Treating it as ordinary text because itâ€™s so short.”…””}”(hjî  h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÙhjë  ubah}”(h]”h ]”h"]”h$]”h&]”Œlevel”KŒtype”jè  Œline”KxŒsource”hÃuh1jÍ  hjñ  ubeŒtransform_messages”]”jÎ  )”}”(hhh]”hÚ)”}”(hhh]”hŒ9Hyperlink target "development-process" is not referenced.”…””}”hj  sbah}”(h]”h ]”h"]”h$]”h&]”uh1hÙhj  ubah}”(h]”h ]”h"]”h$]”h&]”Œlevel”KŒtype”jè  Œsource”hÃŒline”Kuh1jÍ  ubaŒtransformer”NŒinclude_log”]”Œ
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