Patchwork [RFC] Documentation: add documentation for rc-series and merge window

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Submitter Luis R. Rodriguez
Date June 16, 2009, 6:17 p.m.
Message ID <20090616181705.GB31506@tesla>
Download mbox | patch
Permalink /patch/28737/
State RFC
Delegated to: David Miller
Headers show

Comments

Luis R. Rodriguez - June 16, 2009, 6:17 p.m.
On Tue, Jun 16, 2009 at 02:34:01AM -0700, Jouni Malinen wrote:
> On Mon, Jun 15, 2009 at 09:21:14PM -0700, Luis R. Rodriguez wrote:
> 
> > +2.0.2: RC-SERIES RULES
> > +
> > +Rules on what kind of patches are accepted after the merge window closes.
> > +These are patches targeted for the kernel rc-series of a kernel prior
> > +to its release.
> > +
> > + - it must fix a reported regression
> > + - if must fix a reported security hole
> > + - if must fix a reported oops/kernel hang
> 
> 
> s/if/it/ twice..

Thanks, fixed.

> Is there a good reason for documenting different rules for rc-series and
> -stable releases? These three rules look stricter than the ones
> described in stable_kernel_rules.txt:
> 
>  - It must fix a problem that causes a build error (but not for things
>    marked CONFIG_BROKEN), an oops, a hang, data corruption, a real
>    security issue, or some "oh, that's not good" issue.  In short, something
>    critical.

The rc-series rules this patch adds are a summary, so they do indeed appear to be
stricter but I do think new vendor/device ids should be welcomed as well AFAICT,
for instance.

What may be best is to merge these two somehow and refer to the common rules for
both and try to differentiate between them in their respective documentation
section.

But I also think good judgement can be applied, good judgement being defined as
that of a subsystem maintainer, which allows us to simply tell developers to
focus on development and send patches up and the respective maintainer routes
the fixes accordingly.

The spirit of writig this summary is to be clear that rules do exist and that
we cannot simply suggest to read stable_kernel_rules.txt as there are items there
which do not apply.

Reason for trying to add more documentation for this is today there are a lot
companies are working upstream and a better sense of what can get into specific
kernel releases becomes more important and you also have more responsible
developers looking out to ensure their fixes get propagated to the right trees.
So leaving some of these things undocumented, implied or in the dark can turn
out to not be as healthy and IMHO is what lead to the original issue from which
I extracted information to create this summary.

> For example, a fix for data corruption that users can hit relatively
> easily sounds like a good example of something that should really be
> accepted during the rc-phase even if it is not really a regression or
> does not cause a kernel oops/hang.

Agreed.

> "oh, that's not good" issue is somewhat more difficult to comment on,
> but I would expect that there could be some critical issues that really
> would benefit from an exception. What exactly would qualify is something
> that may be not be easily described in a sentence or two, though.
> 
> 
> The main problem I see with having a very hard line on not allowing
> critical fixes (however that would be defined) during the rc-phase is
> that it will take quite a long time to get the fix eventually out. As an
> example, a driver could have a bug that prevents it from working with
> certain subset of devices, but this is noticed only couple of kernel
> releases after the initial driver merge (e.g., for hardware that was not
> yet available for end users at the time the driver was initially
> submitted).

I believe it makes sense to send fixes for new hardware on an old
driver if it is known the fix cannot regress as it does not affect older
hardware.

> In other words, the issue would not be a regression, not a
> security hole, and not an oops/kernel hang. However, it could make the
> driver unusable to large number of users (once the affected hardware
> model becomes available; say in a new laptop).

Agreed. But I think that would fall under the new driver category.

> If an issue is fixed just before a start of the next merge window the
> patch may not have had enough time to go through the maintainers and end
> up in linux-2.6.git in time before the merge window closes. If it
> weren't now allowed in during the rc-phase, it may not go into a stable
> release either (assuming the rc/stable rules are more or less the same)
> and we would be looking something like five month time until the fix
> would actually be released in a proper kernel release. Sure,
> users/distros could take in some additional patches to fix issues they
> care about, but worst case scenarios of close to half a year to fix an
> issue in a kernel release does not sound quite ideal.

Agreed. In the end it seems to come down to the specifics of the patch and
only the maintainer can really be a good judge of whether it should go in
or not. Of course properly documenting each patch helps, and I believe that
in itself may be good enough to address the grey areas.

Here's a new patch with the fix you noted. Also added a little stub about
maintainers judgement, etc.

From: Luis R. Rodriguez <lrodriguez@atheros.com>
Subject: [PATCH] Documentation: add documentation summary for rc-series and merge window

This is losely based on previous discussions on linux-kernel [1][2].
Lets also refer people reading the stable rules to
Documentation/development-process/.

Also add the number of days it has taken between releases,
and provide the average for the last 10 releases: 86.0 days.

[1] http://marc.info/?l=linux-kernel&m=122048427801324&w=2
[2] http://marc.info/?l=linux-netdev&m=122048757705315&w=2

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
---
 Documentation/development-process/2.Process |   96 ++++++++++++++++++++++++---
 Documentation/stable_kernel_rules.txt       |    5 ++
 2 files changed, 91 insertions(+), 10 deletions(-)
Pavel Machek - June 19, 2009, 3 p.m.
On Tue 2009-06-16 11:17:05, Luis R. Rodriguez wrote:
> On Tue, Jun 16, 2009 at 02:34:01AM -0700, Jouni Malinen wrote:
> > On Mon, Jun 15, 2009 at 09:21:14PM -0700, Luis R. Rodriguez wrote:
> > 
> > > +2.0.2: RC-SERIES RULES
> > > +
> > > +Rules on what kind of patches are accepted after the merge window closes.
> > > +These are patches targeted for the kernel rc-series of a kernel prior
> > > +to its release.
> > > +
> > > + - it must fix a reported regression
> > > + - if must fix a reported security hole
> > > + - if must fix a reported oops/kernel hang
> > 
> > 
> > s/if/it/ twice..
> 
> Thanks, fixed.
> 
> > Is there a good reason for documenting different rules for rc-series and
> > -stable releases? These three rules look stricter than the ones
> > described in stable_kernel_rules.txt:
> > 
> >  - It must fix a problem that causes a build error (but not for things
> >    marked CONFIG_BROKEN), an oops, a hang, data corruption, a real
> >    security issue, or some "oh, that's not good" issue.  In short, something
> >    critical.
> 
> The rc-series rules this patch adds are a summary, so they do indeed appear to be
> stricter but I do think new vendor/device ids should be welcomed as well AFAICT,
> for instance.
> 
> What may be best is to merge these two somehow and refer to the common rules for
> both and try to differentiate between them in their respective documentation
> section.
> 
> But I also think good judgement can be applied, good judgement being defined as
> that of a subsystem maintainer, which allows us to simply tell developers to
> focus on development and send patches up and the respective maintainer routes
> the fixes accordingly.
> 
> The spirit of writig this summary is to be clear that rules do exist and that
> we cannot simply suggest to read stable_kernel_rules.txt as there are items there
> which do not apply.
> 
> Reason for trying to add more documentation for this is today there are a lot
> companies are working upstream and a better sense of what can get into specific
> kernel releases becomes more important and you also have more responsible
> developers looking out to ensure their fixes get propagated to the right trees.
> So leaving some of these things undocumented, implied or in the dark can turn
> out to not be as healthy and IMHO is what lead to the original issue from which
> I extracted information to create this summary.
> 
> > For example, a fix for data corruption that users can hit relatively
> > easily sounds like a good example of something that should really be
> > accepted during the rc-phase even if it is not really a regression or
> > does not cause a kernel oops/hang.
> 
> Agreed.
> 
> > "oh, that's not good" issue is somewhat more difficult to comment on,
> > but I would expect that there could be some critical issues that really
> > would benefit from an exception. What exactly would qualify is something
> > that may be not be easily described in a sentence or two, though.
> > 
> > 
> > The main problem I see with having a very hard line on not allowing
> > critical fixes (however that would be defined) during the rc-phase is
> > that it will take quite a long time to get the fix eventually out. As an
> > example, a driver could have a bug that prevents it from working with
> > certain subset of devices, but this is noticed only couple of kernel
> > releases after the initial driver merge (e.g., for hardware that was not
> > yet available for end users at the time the driver was initially
> > submitted).
> 
> I believe it makes sense to send fixes for new hardware on an old
> driver if it is known the fix cannot regress as it does not affect older
> hardware.
> 
> > In other words, the issue would not be a regression, not a
> > security hole, and not an oops/kernel hang. However, it could make the
> > driver unusable to large number of users (once the affected hardware
> > model becomes available; say in a new laptop).
> 
> Agreed. But I think that would fall under the new driver category.
> 
> > If an issue is fixed just before a start of the next merge window the
> > patch may not have had enough time to go through the maintainers and end
> > up in linux-2.6.git in time before the merge window closes. If it
> > weren't now allowed in during the rc-phase, it may not go into a stable
> > release either (assuming the rc/stable rules are more or less the same)
> > and we would be looking something like five month time until the fix
> > would actually be released in a proper kernel release. Sure,
> > users/distros could take in some additional patches to fix issues they
> > care about, but worst case scenarios of close to half a year to fix an
> > issue in a kernel release does not sound quite ideal.
> 
> Agreed. In the end it seems to come down to the specifics of the patch and
> only the maintainer can really be a good judge of whether it should go in
> or not. Of course properly documenting each patch helps, and I believe that
> in itself may be good enough to address the grey areas.
> 
> Here's a new patch with the fix you noted. Also added a little stub about
> maintainers judgement, etc.
> 
> From: Luis R. Rodriguez <lrodriguez@atheros.com>
> Subject: [PATCH] Documentation: add documentation summary for rc-series and merge window
> 
> This is losely based on previous discussions on linux-kernel [1][2].
> Lets also refer people reading the stable rules to
> Documentation/development-process/.
> 
> Also add the number of days it has taken between releases,
> and provide the average for the last 10 releases: 86.0 days.
> 
> [1] http://marc.info/?l=linux-kernel&m=122048427801324&w=2
> [2] http://marc.info/?l=linux-netdev&m=122048757705315&w=2
> 
> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
> ---
>  Documentation/development-process/2.Process |   96 ++++++++++++++++++++++++---
>  Documentation/stable_kernel_rules.txt       |    5 ++
>  2 files changed, 91 insertions(+), 10 deletions(-)
> 
> diff --git a/Documentation/development-process/2.Process b/Documentation/development-process/2.Process
> index d750321..c220646 100644
> --- a/Documentation/development-process/2.Process
> +++ b/Documentation/development-process/2.Process
> @@ -7,20 +7,96 @@ 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.
>  
> +2.0:SUMMARY
> +
> +This section provides a brief summary of the kernel release rules.
> +
> +2.0.0: KERNEL RELEASE RULES
> +
> +Stable kernels are released when they are ready! This means there are
> +absolutely no strict guidelines for sticking to specific dates for a
> +kernel release.
> +
> +2.0.1: MERGE WINDOW
> +
> +The merge window opens up after the next stable kernel is released.
> +The merge window is when maintainers of different subsystem send pull
> +requests to Linus for code they have been queuing up for the next
> +stable kernel. This is typically now done through respective
> +foo-next-2.6.git trees where foo is your subsystem. Each maintainer
> +queues up patches for the next kernel cycle in this foo-next-2.6.git
> +tree. After the merge window the kernel is worked on through the
> +rc-series of the kernel release. The merge window closes at the first
> +rc-series release.
> +
> +After a maintainer has sent his pull request to Linus during the merge
> +window no further new development will be accepted for that tree and
> +as such it marks the closure of development for that subsystem for that
> +kernel cycle. Developers wishing to target deadlines should simply work
> +on their development without regards or consideration for inclusion to
> +a specific kernel release. Once development is done it should simply be
> +posted. If you insist on targeting a kernel release for deadlines you can
> +try to be aware of the current rc cycle development and how soon it seems
> +the next stable kernel release will be made. When Linus notes the last rc
> +cycle released may be the last -- that is a good sign you should already
> +have all your development done and merged in the respective development
> +tree. If your code is not ready and merged into the respective maintainers
> +tree prior to the announced last potential rc kernel release chances are
> +you missed getting your code in for the next kernel merge window.
> +Exemptions here are new drivers, covered below.
> +
> +2.0.2: RC-SERIES RULES
> +
> +Rules on what kind of patches are accepted after the merge window closes.
> +These are patches targeted for the kernel rc-series of a kernel prior
> +to its release.
> +
> + - it must fix a reported regression
> + - it must fix a reported security hole
> + - it must fix a reported oops/kernel hang

- it must fix a bug.

I do not think the 'reported' requirement is there in -rc, and yes,
compile-fixes etc are welcome. Non-intrusive bugfixes too, afaict.
Luis R. Rodriguez - June 19, 2009, 5:10 p.m.
On Fri, Jun 19, 2009 at 8:00 AM, Pavel Machek<pavel@ucw.cz> wrote:
> On Tue 2009-06-16 11:17:05, Luis R. Rodriguez wrote:
>> On Tue, Jun 16, 2009 at 02:34:01AM -0700, Jouni Malinen wrote:
>> > On Mon, Jun 15, 2009 at 09:21:14PM -0700, Luis R. Rodriguez wrote:
>> >
>> > > +2.0.2: RC-SERIES RULES
>> > > +
>> > > +Rules on what kind of patches are accepted after the merge window closes.
>> > > +These are patches targeted for the kernel rc-series of a kernel prior
>> > > +to its release.
>> > > +
>> > > + - it must fix a reported regression
>> > > + - if must fix a reported security hole
>> > > + - if must fix a reported oops/kernel hang
>> >
>> >
>> > s/if/it/ twice..
>>
>> Thanks, fixed.
>>
>> > Is there a good reason for documenting different rules for rc-series and
>> > -stable releases? These three rules look stricter than the ones
>> > described in stable_kernel_rules.txt:
>> >
>> >  - It must fix a problem that causes a build error (but not for things
>> >    marked CONFIG_BROKEN), an oops, a hang, data corruption, a real
>> >    security issue, or some "oh, that's not good" issue.  In short, something
>> >    critical.
>>
>> The rc-series rules this patch adds are a summary, so they do indeed appear to be
>> stricter but I do think new vendor/device ids should be welcomed as well AFAICT,
>> for instance.
>>
>> What may be best is to merge these two somehow and refer to the common rules for
>> both and try to differentiate between them in their respective documentation
>> section.
>>
>> But I also think good judgement can be applied, good judgement being defined as
>> that of a subsystem maintainer, which allows us to simply tell developers to
>> focus on development and send patches up and the respective maintainer routes
>> the fixes accordingly.
>>
>> The spirit of writig this summary is to be clear that rules do exist and that
>> we cannot simply suggest to read stable_kernel_rules.txt as there are items there
>> which do not apply.
>>
>> Reason for trying to add more documentation for this is today there are a lot
>> companies are working upstream and a better sense of what can get into specific
>> kernel releases becomes more important and you also have more responsible
>> developers looking out to ensure their fixes get propagated to the right trees.
>> So leaving some of these things undocumented, implied or in the dark can turn
>> out to not be as healthy and IMHO is what lead to the original issue from which
>> I extracted information to create this summary.
>>
>> > For example, a fix for data corruption that users can hit relatively
>> > easily sounds like a good example of something that should really be
>> > accepted during the rc-phase even if it is not really a regression or
>> > does not cause a kernel oops/hang.
>>
>> Agreed.
>>
>> > "oh, that's not good" issue is somewhat more difficult to comment on,
>> > but I would expect that there could be some critical issues that really
>> > would benefit from an exception. What exactly would qualify is something
>> > that may be not be easily described in a sentence or two, though.
>> >
>> >
>> > The main problem I see with having a very hard line on not allowing
>> > critical fixes (however that would be defined) during the rc-phase is
>> > that it will take quite a long time to get the fix eventually out. As an
>> > example, a driver could have a bug that prevents it from working with
>> > certain subset of devices, but this is noticed only couple of kernel
>> > releases after the initial driver merge (e.g., for hardware that was not
>> > yet available for end users at the time the driver was initially
>> > submitted).
>>
>> I believe it makes sense to send fixes for new hardware on an old
>> driver if it is known the fix cannot regress as it does not affect older
>> hardware.
>>
>> > In other words, the issue would not be a regression, not a
>> > security hole, and not an oops/kernel hang. However, it could make the
>> > driver unusable to large number of users (once the affected hardware
>> > model becomes available; say in a new laptop).
>>
>> Agreed. But I think that would fall under the new driver category.
>>
>> > If an issue is fixed just before a start of the next merge window the
>> > patch may not have had enough time to go through the maintainers and end
>> > up in linux-2.6.git in time before the merge window closes. If it
>> > weren't now allowed in during the rc-phase, it may not go into a stable
>> > release either (assuming the rc/stable rules are more or less the same)
>> > and we would be looking something like five month time until the fix
>> > would actually be released in a proper kernel release. Sure,
>> > users/distros could take in some additional patches to fix issues they
>> > care about, but worst case scenarios of close to half a year to fix an
>> > issue in a kernel release does not sound quite ideal.
>>
>> Agreed. In the end it seems to come down to the specifics of the patch and
>> only the maintainer can really be a good judge of whether it should go in
>> or not. Of course properly documenting each patch helps, and I believe that
>> in itself may be good enough to address the grey areas.
>>
>> Here's a new patch with the fix you noted. Also added a little stub about
>> maintainers judgement, etc.
>>
>> From: Luis R. Rodriguez <lrodriguez@atheros.com>
>> Subject: [PATCH] Documentation: add documentation summary for rc-series and merge window
>>
>> This is losely based on previous discussions on linux-kernel [1][2].
>> Lets also refer people reading the stable rules to
>> Documentation/development-process/.
>>
>> Also add the number of days it has taken between releases,
>> and provide the average for the last 10 releases: 86.0 days.
>>
>> [1] http://marc.info/?l=linux-kernel&m=122048427801324&w=2
>> [2] http://marc.info/?l=linux-netdev&m=122048757705315&w=2
>>
>> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
>> ---
>>  Documentation/development-process/2.Process |   96 ++++++++++++++++++++++++---
>>  Documentation/stable_kernel_rules.txt       |    5 ++
>>  2 files changed, 91 insertions(+), 10 deletions(-)
>>
>> diff --git a/Documentation/development-process/2.Process b/Documentation/development-process/2.Process
>> index d750321..c220646 100644
>> --- a/Documentation/development-process/2.Process
>> +++ b/Documentation/development-process/2.Process
>> @@ -7,20 +7,96 @@ 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.
>>
>> +2.0:SUMMARY
>> +
>> +This section provides a brief summary of the kernel release rules.
>> +
>> +2.0.0: KERNEL RELEASE RULES
>> +
>> +Stable kernels are released when they are ready! This means there are
>> +absolutely no strict guidelines for sticking to specific dates for a
>> +kernel release.
>> +
>> +2.0.1: MERGE WINDOW
>> +
>> +The merge window opens up after the next stable kernel is released.
>> +The merge window is when maintainers of different subsystem send pull
>> +requests to Linus for code they have been queuing up for the next
>> +stable kernel. This is typically now done through respective
>> +foo-next-2.6.git trees where foo is your subsystem. Each maintainer
>> +queues up patches for the next kernel cycle in this foo-next-2.6.git
>> +tree. After the merge window the kernel is worked on through the
>> +rc-series of the kernel release. The merge window closes at the first
>> +rc-series release.
>> +
>> +After a maintainer has sent his pull request to Linus during the merge
>> +window no further new development will be accepted for that tree and
>> +as such it marks the closure of development for that subsystem for that
>> +kernel cycle. Developers wishing to target deadlines should simply work
>> +on their development without regards or consideration for inclusion to
>> +a specific kernel release. Once development is done it should simply be
>> +posted. If you insist on targeting a kernel release for deadlines you can
>> +try to be aware of the current rc cycle development and how soon it seems
>> +the next stable kernel release will be made. When Linus notes the last rc
>> +cycle released may be the last -- that is a good sign you should already
>> +have all your development done and merged in the respective development
>> +tree. If your code is not ready and merged into the respective maintainers
>> +tree prior to the announced last potential rc kernel release chances are
>> +you missed getting your code in for the next kernel merge window.
>> +Exemptions here are new drivers, covered below.
>> +
>> +2.0.2: RC-SERIES RULES
>> +
>> +Rules on what kind of patches are accepted after the merge window closes.
>> +These are patches targeted for the kernel rc-series of a kernel prior
>> +to its release.
>> +
>> + - it must fix a reported regression
>> + - it must fix a reported security hole
>> + - it must fix a reported oops/kernel hang
>
> - it must fix a bug.

Well that's for certain, but there is a difference between a general
notion of a bug and the type of bug fixes that should go in during the
rc-series. This documentation patch highlights the difference.

> I do not think the 'reported' requirement is there in -rc,

Well if its not reported how else would you find out about it during
the rc-series? And if its something easily triggerable that should
have been fixed earlier, not late in the rc-series.

> and yes,
> compile-fixes etc are welcome.

Sure, but what are these doing so late in the rc-series?

> Non-intrusive bugfixes too, afaict.

It really depends on what you mean but generally no, and this is why I
think this clarification is important.

  Luis
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Justin Mattock - June 19, 2009, 5:41 p.m.
On Fri, Jun 19, 2009 at 10:10 AM, Luis R.
Rodriguez<lrodriguez@atheros.com> wrote:
> On Fri, Jun 19, 2009 at 8:00 AM, Pavel Machek<pavel@ucw.cz> wrote:
>> On Tue 2009-06-16 11:17:05, Luis R. Rodriguez wrote:
>>> On Tue, Jun 16, 2009 at 02:34:01AM -0700, Jouni Malinen wrote:
>>> > On Mon, Jun 15, 2009 at 09:21:14PM -0700, Luis R. Rodriguez wrote:
>>> >
>>> > > +2.0.2: RC-SERIES RULES
>>> > > +
>>> > > +Rules on what kind of patches are accepted after the merge window closes.
>>> > > +These are patches targeted for the kernel rc-series of a kernel prior
>>> > > +to its release.
>>> > > +
>>> > > + - it must fix a reported regression
>>> > > + - if must fix a reported security hole
>>> > > + - if must fix a reported oops/kernel hang
>>> >
>>> >
>>> > s/if/it/ twice..
>>>
>>> Thanks, fixed.
>>>
>>> > Is there a good reason for documenting different rules for rc-series and
>>> > -stable releases? These three rules look stricter than the ones
>>> > described in stable_kernel_rules.txt:
>>> >
>>> >  - It must fix a problem that causes a build error (but not for things
>>> >    marked CONFIG_BROKEN), an oops, a hang, data corruption, a real
>>> >    security issue, or some "oh, that's not good" issue.  In short, something
>>> >    critical.
>>>
>>> The rc-series rules this patch adds are a summary, so they do indeed appear to be
>>> stricter but I do think new vendor/device ids should be welcomed as well AFAICT,
>>> for instance.
>>>
>>> What may be best is to merge these two somehow and refer to the common rules for
>>> both and try to differentiate between them in their respective documentation
>>> section.
>>>
>>> But I also think good judgement can be applied, good judgement being defined as
>>> that of a subsystem maintainer, which allows us to simply tell developers to
>>> focus on development and send patches up and the respective maintainer routes
>>> the fixes accordingly.
>>>
>>> The spirit of writig this summary is to be clear that rules do exist and that
>>> we cannot simply suggest to read stable_kernel_rules.txt as there are items there
>>> which do not apply.
>>>
>>> Reason for trying to add more documentation for this is today there are a lot
>>> companies are working upstream and a better sense of what can get into specific
>>> kernel releases becomes more important and you also have more responsible
>>> developers looking out to ensure their fixes get propagated to the right trees.
>>> So leaving some of these things undocumented, implied or in the dark can turn
>>> out to not be as healthy and IMHO is what lead to the original issue from which
>>> I extracted information to create this summary.
>>>
>>> > For example, a fix for data corruption that users can hit relatively
>>> > easily sounds like a good example of something that should really be
>>> > accepted during the rc-phase even if it is not really a regression or
>>> > does not cause a kernel oops/hang.
>>>
>>> Agreed.
>>>
>>> > "oh, that's not good" issue is somewhat more difficult to comment on,
>>> > but I would expect that there could be some critical issues that really
>>> > would benefit from an exception. What exactly would qualify is something
>>> > that may be not be easily described in a sentence or two, though.
>>> >
>>> >
>>> > The main problem I see with having a very hard line on not allowing
>>> > critical fixes (however that would be defined) during the rc-phase is
>>> > that it will take quite a long time to get the fix eventually out. As an
>>> > example, a driver could have a bug that prevents it from working with
>>> > certain subset of devices, but this is noticed only couple of kernel
>>> > releases after the initial driver merge (e.g., for hardware that was not
>>> > yet available for end users at the time the driver was initially
>>> > submitted).
>>>
>>> I believe it makes sense to send fixes for new hardware on an old
>>> driver if it is known the fix cannot regress as it does not affect older
>>> hardware.
>>>
>>> > In other words, the issue would not be a regression, not a
>>> > security hole, and not an oops/kernel hang. However, it could make the
>>> > driver unusable to large number of users (once the affected hardware
>>> > model becomes available; say in a new laptop).
>>>
>>> Agreed. But I think that would fall under the new driver category.
>>>
>>> > If an issue is fixed just before a start of the next merge window the
>>> > patch may not have had enough time to go through the maintainers and end
>>> > up in linux-2.6.git in time before the merge window closes. If it
>>> > weren't now allowed in during the rc-phase, it may not go into a stable
>>> > release either (assuming the rc/stable rules are more or less the same)
>>> > and we would be looking something like five month time until the fix
>>> > would actually be released in a proper kernel release. Sure,
>>> > users/distros could take in some additional patches to fix issues they
>>> > care about, but worst case scenarios of close to half a year to fix an
>>> > issue in a kernel release does not sound quite ideal.
>>>
>>> Agreed. In the end it seems to come down to the specifics of the patch and
>>> only the maintainer can really be a good judge of whether it should go in
>>> or not. Of course properly documenting each patch helps, and I believe that
>>> in itself may be good enough to address the grey areas.
>>>
>>> Here's a new patch with the fix you noted. Also added a little stub about
>>> maintainers judgement, etc.
>>>
>>> From: Luis R. Rodriguez <lrodriguez@atheros.com>
>>> Subject: [PATCH] Documentation: add documentation summary for rc-series and merge window
>>>
>>> This is losely based on previous discussions on linux-kernel [1][2].
>>> Lets also refer people reading the stable rules to
>>> Documentation/development-process/.
>>>
>>> Also add the number of days it has taken between releases,
>>> and provide the average for the last 10 releases: 86.0 days.
>>>
>>> [1] http://marc.info/?l=linux-kernel&m=122048427801324&w=2
>>> [2] http://marc.info/?l=linux-netdev&m=122048757705315&w=2
>>>
>>> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
>>> ---
>>>  Documentation/development-process/2.Process |   96 ++++++++++++++++++++++++---
>>>  Documentation/stable_kernel_rules.txt       |    5 ++
>>>  2 files changed, 91 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/Documentation/development-process/2.Process b/Documentation/development-process/2.Process
>>> index d750321..c220646 100644
>>> --- a/Documentation/development-process/2.Process
>>> +++ b/Documentation/development-process/2.Process
>>> @@ -7,20 +7,96 @@ 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.
>>>
>>> +2.0:SUMMARY
>>> +
>>> +This section provides a brief summary of the kernel release rules.
>>> +
>>> +2.0.0: KERNEL RELEASE RULES
>>> +
>>> +Stable kernels are released when they are ready! This means there are
>>> +absolutely no strict guidelines for sticking to specific dates for a
>>> +kernel release.
>>> +
>>> +2.0.1: MERGE WINDOW
>>> +
>>> +The merge window opens up after the next stable kernel is released.
>>> +The merge window is when maintainers of different subsystem send pull
>>> +requests to Linus for code they have been queuing up for the next
>>> +stable kernel. This is typically now done through respective
>>> +foo-next-2.6.git trees where foo is your subsystem. Each maintainer
>>> +queues up patches for the next kernel cycle in this foo-next-2.6.git
>>> +tree. After the merge window the kernel is worked on through the
>>> +rc-series of the kernel release. The merge window closes at the first
>>> +rc-series release.
>>> +
>>> +After a maintainer has sent his pull request to Linus during the merge
>>> +window no further new development will be accepted for that tree and
>>> +as such it marks the closure of development for that subsystem for that
>>> +kernel cycle. Developers wishing to target deadlines should simply work
>>> +on their development without regards or consideration for inclusion to
>>> +a specific kernel release. Once development is done it should simply be
>>> +posted. If you insist on targeting a kernel release for deadlines you can
>>> +try to be aware of the current rc cycle development and how soon it seems
>>> +the next stable kernel release will be made. When Linus notes the last rc
>>> +cycle released may be the last -- that is a good sign you should already
>>> +have all your development done and merged in the respective development
>>> +tree. If your code is not ready and merged into the respective maintainers
>>> +tree prior to the announced last potential rc kernel release chances are
>>> +you missed getting your code in for the next kernel merge window.
>>> +Exemptions here are new drivers, covered below.
>>> +
>>> +2.0.2: RC-SERIES RULES
>>> +
>>> +Rules on what kind of patches are accepted after the merge window closes.
>>> +These are patches targeted for the kernel rc-series of a kernel prior
>>> +to its release.
>>> +
>>> + - it must fix a reported regression
>>> + - it must fix a reported security hole
>>> + - it must fix a reported oops/kernel hang
>>
>> - it must fix a bug.
>
> Well that's for certain, but there is a difference between a general
> notion of a bug and the type of bug fixes that should go in during the
> rc-series. This documentation patch highlights the difference.
>
>> I do not think the 'reported' requirement is there in -rc,
>
> Well if its not reported how else would you find out about it during
> the rc-series? And if its something easily triggerable that should
> have been fixed earlier, not late in the rc-series.
>
>> and yes,
>> compile-fixes etc are welcome.
>
> Sure, but what are these doing so late in the rc-series?
>
>> Non-intrusive bugfixes too, afaict.
>
> It really depends on what you mean but generally no, and this is why I
> think this clarification is important.
>
>  Luis
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>

well, this answers my question about merge window
times and, what types of patches belong where.
Pavel Machek - June 19, 2009, 10:19 p.m.
> >> +2.0.2: RC-SERIES RULES
> >> +
> >> +Rules on what kind of patches are accepted after the merge window closes.
> >> +These are patches targeted for the kernel rc-series of a kernel prior
> >> +to its release.
> >> +
> >> + - it must fix a reported regression
> >> + - it must fix a reported security hole
> >> + - it must fix a reported oops/kernel hang
> >
> > - it must fix a bug.
> 
> Well that's for certain, but there is a difference between a general
> notion of a bug and the type of bug fixes that should go in during the
> rc-series. This documentation patch highlights the difference.

Yes, and I'm trying to tell you that this documentation patch is
wrong.

Non-intrusive bugfixes _are_ welcome after -rc1.

> > I do not think the 'reported' requirement is there in -rc,
> 
> Well if its not reported how else would you find out about it during
> the rc-series? And if its something easily triggerable that should
> have been fixed earlier, not late in the rc-series.

'reported' means 'someone is hitting that bug' in that context. If you
do code inspection on drivers/foo/bar.c and find that it will hang on
may 13, 2017; then that's a bug but not "reported" one -- users are
not hitting it. Such bug may be uninteresting for -stable, but would
probably be ok for -rc.

> > and yes,
> > compile-fixes etc are welcome.
> 
> Sure, but what are these doing so late in the rc-series?

Bugs happen :-).

> > Non-intrusive bugfixes too, afaict.
> 
> It really depends on what you mean but generally no, and this is why I
> think this clarification is important.

I believe you are wrong.
									Pavel
Krzysztof Halasa - June 19, 2009, 10:49 p.m.
Pavel Machek <pavel@ucw.cz> writes:

> Non-intrusive bugfixes _are_ welcome after -rc1.

I'm under impression that the merge window is for new features, and past
rc1 only fixes are accepted. It may be different past maybe rc6, and
obviously the fixes must be sane enough (even in merge window).

Do they have to fix a bug? I don't know, I guess they can also fix "an
issue" :-)
Luis R. Rodriguez - June 19, 2009, 10:51 p.m.
On Fri, Jun 19, 2009 at 3:19 PM, Pavel Machek<pavel@ucw.cz> wrote:
>
>> >> +2.0.2: RC-SERIES RULES
>> >> +
>> >> +Rules on what kind of patches are accepted after the merge window closes.
>> >> +These are patches targeted for the kernel rc-series of a kernel prior
>> >> +to its release.
>> >> +
>> >> + - it must fix a reported regression
>> >> + - it must fix a reported security hole
>> >> + - it must fix a reported oops/kernel hang
>> >
>> > - it must fix a bug.
>>
>> Well that's for certain, but there is a difference between a general
>> notion of a bug and the type of bug fixes that should go in during the
>> rc-series. This documentation patch highlights the difference.
>
> Yes, and I'm trying to tell you that this documentation patch is
> wrong.

This mean you might be able to help correct this.

> Non-intrusive bugfixes _are_ welcome after -rc1.

That's great news to me.

I think it would really help to get a clarification on what is meant
by "non-intrusive bugfixes" though. Can you elaborate on that?

>> > Non-intrusive bugfixes too, afaict.
>>
>> It really depends on what you mean but generally no, and this is why I
>> think this clarification is important.
>
> I believe you are wrong.

I was actually hoping I would be. But I'd like some confirmation that I am.

For example, based on your feedback we have a series of fixes we'd
like to try to get merged for 2.6.31-rc2 for ath9k. I have been under
the impression that since those fixes do not meet the criteria
clarified by my original patch on documentation for the rc-series that
they would not get merged and our only option to get users to get
these patches is to wait for 2.6.32 or use some sort of bleeding edge
backport package. We try hard to get out our patches in time prior to
the merge window but sometimes some patches don't manage hit that
timeline so if you tell me we can certainly send "non-intrusive bug
fixes" post rc1 then that is what we will try to do. I just do not
want to get bitch slapped about it when we do.

  Luis
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Linus Torvalds - June 19, 2009, 10:56 p.m.
On Sat, 20 Jun 2009, Pavel Machek wrote:
> 
> Non-intrusive bugfixes _are_ welcome after -rc1.

After -rc1, yes.

After something like -rc5? No.

They had better be _really_ important things, and _really_ obvious and 
non-intrusive.  Not just "any bug".

		Linus
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Luis R. Rodriguez - June 21, 2009, 12:47 a.m.
On Fri, Jun 19, 2009 at 3:56 PM, Linus
Torvalds<torvalds@linux-foundation.org> wrote:
>
>
> On Sat, 20 Jun 2009, Pavel Machek wrote:
>>
>> Non-intrusive bugfixes _are_ welcome after -rc1.
>
> After -rc1, yes.
>
> After something like -rc5? No.
>
> They had better be _really_ important things, and _really_ obvious and
> non-intrusive.  Not just "any bug".

For the sake of documentation and to help developers better understand
this it would be nice if we could be a little more clear here. I can
think of patches which may not be obvious but yet very important, for
example. Can we simply document that the patches must be important,
non-intrusive, and must have a very clear commit log entry of what it
is fixing. Judgment for the degree of importance of the patch can be
left up to the subsystem maintainer.

Is it reasonable to document this as I describe above?

  Luis
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Pavel Machek - June 21, 2009, 6:24 a.m.
> > Non-intrusive bugfixes _are_ welcome after -rc1.
> 
> That's great news to me.
> 
> I think it would really help to get a clarification on what is meant
> by "non-intrusive bugfixes" though. Can you elaborate on that?

Typo fix in printk() is non-intrusive, 'apply this series' is
borderline; if issue is bad enough it may be ok. I guess only Linus
can clarify more.

> >> > Non-intrusive bugfixes too, afaict.
> >>
> >> It really depends on what you mean but generally no, and this is why I
> >> think this clarification is important.
> >
> > I believe you are wrong.
> 
> I was actually hoping I would be. But I'd like some confirmation that I am.
> 
> For example, based on your feedback we have a series of fixes we'd
> like to try to get merged for 2.6.31-rc2 for ath9k. I have been under
> the impression that since those fixes do not meet the criteria
> clarified by my original patch on documentation for the rc-series that
> they would not get merged and our only option to get users to get
> these patches is to wait for 2.6.32 or use some sort of bleeding edge
> backport package. We try hard to get out our patches in time prior

I believe 'no git merges after rc1' is one of rules.
									Pavel

Patch

diff --git a/Documentation/development-process/2.Process b/Documentation/development-process/2.Process
index d750321..c220646 100644
--- a/Documentation/development-process/2.Process
+++ b/Documentation/development-process/2.Process
@@ -7,20 +7,96 @@  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.
 
+2.0:SUMMARY
+
+This section provides a brief summary of the kernel release rules.
+
+2.0.0: KERNEL RELEASE RULES
+
+Stable kernels are released when they are ready! This means there are
+absolutely no strict guidelines for sticking to specific dates for a
+kernel release.
+
+2.0.1: MERGE WINDOW
+
+The merge window opens up after the next stable kernel is released.
+The merge window is when maintainers of different subsystem send pull
+requests to Linus for code they have been queuing up for the next
+stable kernel. This is typically now done through respective
+foo-next-2.6.git trees where foo is your subsystem. Each maintainer
+queues up patches for the next kernel cycle in this foo-next-2.6.git
+tree. After the merge window the kernel is worked on through the
+rc-series of the kernel release. The merge window closes at the first
+rc-series release.
+
+After a maintainer has sent his pull request to Linus during the merge
+window no further new development will be accepted for that tree and
+as such it marks the closure of development for that subsystem for that
+kernel cycle. Developers wishing to target deadlines should simply work
+on their development without regards or consideration for inclusion to
+a specific kernel release. Once development is done it should simply be
+posted. If you insist on targeting a kernel release for deadlines you can
+try to be aware of the current rc cycle development and how soon it seems
+the next stable kernel release will be made. When Linus notes the last rc
+cycle released may be the last -- that is a good sign you should already
+have all your development done and merged in the respective development
+tree. If your code is not ready and merged into the respective maintainers
+tree prior to the announced last potential rc kernel release chances are
+you missed getting your code in for the next kernel merge window.
+Exemptions here are new drivers, covered below.
+
+2.0.2: RC-SERIES RULES
+
+Rules on what kind of patches are accepted after the merge window closes.
+These are patches targeted for the kernel rc-series of a kernel prior
+to its release.
+
+ - it must fix a reported regression
+ - it must fix a reported security hole
+ - it must fix a reported oops/kernel hang
+
+This means any small-non-fix code changes, although they might fix an issue,
+will not be accepted. If the patch in question is for a driver that has been
+around for more than a kernel release, then "small fixes" really can't be
+worth all that much. And "small fixes" may be small and "obvious" they
+definitely can regress.
+
+When in doubt consult with your subsystem maintainer or just allow him to
+do the judging of where the patches deserves to go to, a proper commit log
+should help with this effort.
+
+2.0.3 RC-SERIES NEW DRIVER EXEMPTION RULE
+
+The very first release a new driver (or filesystem) is special. New drivers
+are accepted during the rc series. Patches for the same driver then are
+also accepted during the same rc series of a kernel as well as fixes as it
+cannot regress as no previous kernels exists with it.
+
+Once drivers are upstream for one kernel release (say on 2.6.29) the target
+*goal* after the merge window of the next kernel (respectively this would be
+the 2.6.30 rc-series) is to address regressions. Kernel oops/hangs and security
+issues are obviously accepted but the point is these should have also been
+caught earlier as a general development goal. The rc-series focus should really
+be to address regressions.
 
 2.1: THE BIG PICTURE
 
 The kernel developers use a loosely time-based release process, with a new
-major kernel release happening every two or three months.  The recent
-release history looks like this:
-
-	2.6.26	July 13, 2008
-	2.6.25	April 16, 2008
-	2.6.24	January 24, 2008
-	2.6.23	October 9, 2007
-	2.6.22	July 8, 2007
-	2.6.21	April 25, 2007
-	2.6.20	February 4, 2007
+major kernel release happening about every two or three months. The current
+average time based on the last 10 releases is 86.0 days. The recent release
+history along with the number of days between each release looks like this:
+
+	2.6.30	June 10, 2009 - 78 days
+	2.6.29  March 23, 2009 - 89 days
+	2.6.28	December 29, 2008 - 76 days
+	2.6.27	October 8, 2008 - 88 days
+	2.6.26	July 13, 2008 - 88 days
+	2.6.25	April 16, 2008 - 83 days
+	2.6.24	January 24, 2008 - 108 days
+	2.6.23	October 9, 2007 - 94 days
+	2.6.22	July 8, 2007 - 75 days
+	2.6.21	April 25, 2007 - 81 days
+	2.6.20	February 4, 2007 - 68
 
 Every 2.6.x release is a major kernel release with new features, internal
 API changes, and more.  A typical 2.6 release can contain over 10,000
diff --git a/Documentation/stable_kernel_rules.txt b/Documentation/stable_kernel_rules.txt
index a452227..113e8c8 100644
--- a/Documentation/stable_kernel_rules.txt
+++ b/Documentation/stable_kernel_rules.txt
@@ -1,5 +1,10 @@ 
 Everything you ever wanted to know about Linux 2.6 -stable releases.
 
+For further details, such as stable kernel release schedules, rc-series
+policies and process of development please refer to:
+
+Documentation/development-process/
+
 Rules on what kind of patches are accepted, and which ones are not, into the
 "-stable" tree: