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civilinfrastructureplatform:cipkernelmaintenance [2018/05/28 11:07] Agustin Benito Bethencourt [CIP kernel - SLTS kernel] |
civilinfrastructureplatform:cipkernelmaintenance [2024/05/07 08:55] nobuhiro.iwamatsu [Kernel maintenance team] |
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===== Kernel maintenance team ===== | ===== Kernel maintenance team ===== | ||
- | Ben Hutchings, from Codethink Ltd. is the initial CIP kernel maintainer. Daniel Wagner, from Siemens AG, joined the kernel maintenance team in 2017 as maintainer of an -rt branch of the CIP kernel. More developers will join in future. | + | |
+ | Nobuhiro Iwamatsu, from Toshiba Corporation. and Pavel Machek, from DENX Software Engineering GmbH are the current CIP kernel maintainer. More developers will join in future. | ||
+ | And when we release the CIP kernel, we will sign it with GnuPG by the maintainers. Each public key can be obtained from the following. | ||
+ | * Nobuhiro Iwamatsu ([[https://keys.openpgp.org/search?q=5E629EE5232197357B84CF4332247FBB40AD1FA6]]) | ||
+ | * Pavel Machek ([[http://keys.gnupg.net/pks/lookup?op=get&search=0x30E7F06A95DBFAF2|0x4F7CF3BBAF478086 4D35D2FD30E7F06A95DBFAF2]]) | ||
===== CIP kernel maintenance policies ===== | ===== CIP kernel maintenance policies ===== | ||
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CIP will measure the effort involved in maintaining the kernel branch we already labelled as SLTS (4.4) and study the technical implications of this work during 2018 in order to define when the next SLTS branch should be started. | CIP will measure the effort involved in maintaining the kernel branch we already labelled as SLTS (4.4) and study the technical implications of this work during 2018 in order to define when the next SLTS branch should be started. | ||
- | === How long will 4.4 SLTS branch be maintained? === | + | === How long will SLTS branches be maintained? === |
- | The use cases CIP project is targeting have a life cycle of between 25 and 50 years. In theory, this is the time in which products shipped with the CIP kernel will be under maintenance. However, identifying and backporting relevant fixes becomes increasingly difficult as upstream kernel development diverges further from a stable branch. Any given SLTS branch is unlikely to be maintainable for more than 10-20 years. | + | The use cases CIP project is targeting have a life cycle of between 25 and 50 years. In theory, this is the time in which products shipped with the CIP kernel will be under maintenance. However, identifying and backporting relevant fixes becomes increasingly difficult as upstream kernel development diverges further from a stable branch. Any given SLTS branch is unlikely to be economically maintainable for much more than 10 years. |
The Linux kernel 4.4 was [[http://lkml.iu.edu/hypermail/linux/kernel/1601.1/01592.html|released on January 10th 2016]]. It was [[https://kernel.org/releases.html|declared LTS (Long Term Support) by the stable team]] which means Greg Kroah-Hartman was supposed to maintain it for two years (Feb 2018) following the kernel LTS process. In September 2017 it was announced that the 4.4 LTS branch will be maintained during 6 years. Another stable maintainer could extend LTS maintenance for some time beyond that. After that period, CIP will maintain it. | The Linux kernel 4.4 was [[http://lkml.iu.edu/hypermail/linux/kernel/1601.1/01592.html|released on January 10th 2016]]. It was [[https://kernel.org/releases.html|declared LTS (Long Term Support) by the stable team]] which means Greg Kroah-Hartman was supposed to maintain it for two years (Feb 2018) following the kernel LTS process. In September 2017 it was announced that the 4.4 LTS branch will be maintained during 6 years. Another stable maintainer could extend LTS maintenance for some time beyond that. After that period, CIP will maintain it. | ||
+ | |||
+ | The Linux kernel 4.19 was released on October 22nd, 2018. | ||
==== Suitable changes ==== | ==== Suitable changes ==== | ||
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As we will be backporting fixes from mainline, which [[https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/stable-api-nonsense.rst|may change in-kernel APIs]], we will not guarantee API or ABI stability within an SLTS branch. It is the responsibility of members to update any out-of-tree components they use in case they are affected by such a change. However, incompatible changes to user-space APIs or ABIs will not be acceptable. | As we will be backporting fixes from mainline, which [[https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/stable-api-nonsense.rst|may change in-kernel APIs]], we will not guarantee API or ABI stability within an SLTS branch. It is the responsibility of members to update any out-of-tree components they use in case they are affected by such a change. However, incompatible changes to user-space APIs or ABIs will not be acceptable. | ||
- | Initially, CIP will release a new CIP minor kernel version approximately once a month. You can find the [[https://gitlab.com/cip-project/linux-cip|latest CIP kernel]] version in gitlab. Each release will be announced in the cip-dev mailing list and occasionally on the new section of the [[https://www.cip-project.org/news|CIP project]] website. | + | CIP has released new CIP minor kernel version. This depends on the kernel version and flavor. linux-4.4.y is scheduled to be released once a month, linux-4.19.y is scheduled to be released twice a month, and the RT kernel is scheduled to be released once every two months. |
+ | You can find the [[https://git.kernel.org/pub/scm/linux/kernel/git/cip/linux-cip.git/|latest CIP kernel]] version in [[https://git.kernel.org|git.kernel.org]]. Each release will be announced in the cip-dev mailing list and occasionally on the new section of the [[https://www.cip-project.org/news|CIP project]] website. | ||
==== Maintenance Scope ==== | ==== Maintenance Scope ==== | ||
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The embedded systems that CIP will be used in will also often require out-of-tree drivers and will sometimes include other changes of unknown quality to their kernel. These modifications are in general unsupported. If a bug is found in such a modified kernel, Members will first demonstrate that it exists in the CIP source release in order for the CIP maintainers to act on it. | The embedded systems that CIP will be used in will also often require out-of-tree drivers and will sometimes include other changes of unknown quality to their kernel. These modifications are in general unsupported. If a bug is found in such a modified kernel, Members will first demonstrate that it exists in the CIP source release in order for the CIP maintainers to act on it. | ||
- | For specific CIP applied patches, the default communication channel will be the [[https://lists.cip-project.org/mailman/listinfo/cip-dev|CIP-dev]] mailing list. | + | For specific CIP applied patches, the default communication channel will be the [[https://lists.cip-project.org/mailman/listinfo/cip-dev|CIP-dev]] mailing list. Patches sent to the cip-dev mailing list are tracked on [[https://patchwork.kernel.org/project/cip-dev/list/|patchwork]] since October 12th, 2018. |
+ | |||
+ | [[https://gitlab.com/cip-project/cip-kernel/cip-kernel-config|Kernel configuration files]] provided by Members will be used as a reference to limit the maintenance scope. Here is a list of recommendations related to kernel configuration for long-term support: | ||
+ | * [[https://lists.cip-project.org/pipermail/cip-dev/2017-May/000263.html]] | ||
+ | * [[https://lists.cip-project.org/pipermail/cip-dev/2017-July/000387.html]] | ||
+ | * [[https://lists.cip-project.org/pipermail/cip-dev/2018-October/001578.html]] | ||
==== Security fixes ==== | ==== Security fixes ==== | ||
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Although this goal may be achievable for CIP, its members may take much longer to release and deploy binary updates, maybe due to valid concerns about the risk of regression or limited opportunities to deploy updates. In the worst case, they may use CIP as an advertising/compliance point - please don't do that! | Although this goal may be achievable for CIP, its members may take much longer to release and deploy binary updates, maybe due to valid concerns about the risk of regression or limited opportunities to deploy updates. In the worst case, they may use CIP as an advertising/compliance point - please don't do that! | ||
- | To track [[https://cve.mitre.org/about/|CVE]] status in each branch and provide this information either to members or publicly some scripts has been [[https://gitlab.com/cip-project/cip-kernel-sec|developed and published]] by Ben Hutchings. | + | To track [[https://cve.mitre.org/about/|CVE]] status in each branch and provide this information either to members or publicly some scripts has been [[https://gitlab.com/cip-project/cip-kernel/cip-kernel-sec|developed and published]] by Masami Ichikawa. |
===== Patch review howto ===== | ===== Patch review howto ===== | ||
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Pending patches for stable can be found at: | Pending patches for stable can be found at: | ||
- | * Ben Hutchings [[https://git.kernel.org/pub/scm/linux/kernel/git/bwh/linux-stable-queue.git/|queue]]. | ||
* Greg Kroah-Hartman [[https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/|queue]]. | * Greg Kroah-Hartman [[https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/|queue]]. | ||
- | * Alexander Levin [[https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git/|queue]]. | + | * Alexander (Sasha) Levin [[https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git/|queue]]. |
- | * Willy Tarreau [[https://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/linux-stable.git/|queue]]. | + | |
==== Filter the patches ==== | ==== Filter the patches ==== | ||
- | Does the patch touch code that's maintained in the CIP branch? (This should be scripted. If not, ignore it and move on. | + | Does the patch touch code that's maintained in the CIP branch? (This should be scripted. If not, ignore it and move on.) |
==== Read the commit message ==== | ==== Read the commit message ==== | ||
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* If there is already a fix in Linus's git repository, ask for it to be included in a stable update straight away. | * If there is already a fix in Linus's git repository, ask for it to be included in a stable update straight away. | ||
* Otherwise, if the patch that introduces the regression hasn't yet been applied then you should ask for it to be deferred (or never applied, if it was reverted upstream). | * Otherwise, if the patch that introduces the regression hasn't yet been applied then you should ask for it to be deferred (or never applied, if it was reverted upstream). | ||
+ | |||
+ | ==== CIP kernel maintenance status ==== | ||
+ | * [[linux-4.4.y| linux-4.4.y review]] | ||
+ | * new reviews are done in lts-commit-list repository | ||
+ | * [[linux-4.4-failed-patches| linux-4.4.y failed patches]] | ||
+ | |||
+ | ==== CIP kernel release tutorial ==== | ||
+ | * [[civilinfrastructureplatform:cipkernelmaintenance_release_tutorial|CIP kernel release tutorial]] | ||
[[start|Back to the parent page]] | [[start|Back to the parent page]] | ||