回复: [RFC V2] Create supported branch from edk2-stable* tag (Required to address critical bug BZ3111)

["gaoliming" <gaoliming@byosoft.com.cn>]

Mike:

> -----邮件原件-----
> 发件人: Kinney, Michael D <michael.d.kinney@intel.com>
> 发送时间: 2020年12月16日 10:52
> 收件人: gaoliming <gaoliming@byosoft.com.cn>; devel@edk2.groups.io;
> rfc@edk2.groups.io; 'Andrew Fish' <afish@apple.com>; 'Leif Lindholm'
> <leif@nuviainc.com>; lersek@redhat.com; 'Sean Brogan'
> <sean.brogan@microsoft.com>; 'Bret Barkelew'
> <Bret.Barkelew@microsoft.com>; Kinney, Michael D
> <michael.d.kinney@intel.com>
> 主题: RE: [RFC V2] Create supported branch from edk2-stable* tag (Required
> to address critical bug BZ3111)
> 
> > -----Original Message-----
> > From: gaoliming <gaoliming@byosoft.com.cn>
> > Sent: Tuesday, December 15, 2020 5:19 PM
> > To: Kinney, Michael D <michael.d.kinney@intel.com>;
> devel@edk2.groups.io; rfc@edk2.groups.io; 'Andrew Fish'
> > <afish@apple.com>; 'Leif Lindholm' <leif@nuviainc.com>;
> lersek@redhat.com; 'Sean Brogan' <sean.brogan@microsoft.com>;
> > 'Bret Barkelew' <Bret.Barkelew@microsoft.com>
> > Subject: 回复: [RFC V2] Create supported branch from edk2-stable* tag
> (Required to address critical bug BZ3111)
> >
> > Mike:
> >
> > > -----邮件原件-----
> > > 发件人: Kinney, Michael D <michael.d.kinney@intel.com>
> > > 发送时间: 2020年12月16日 8:25
> > > 收件人: devel@edk2.groups.io; rfc@edk2.groups.io;
> > > gaoliming@byosoft.com.cn; Andrew Fish (afish@apple.com)
> > > <afish@apple.com>; Leif Lindholm <leif@nuviainc.com>; Laszlo Ersek
> > > <lersek@redhat.com> (lersek@redhat.com) <lersek@redhat.com>; 'Sean
> > > Brogan' <sean.brogan@microsoft.com>; 'Bret Barkelew'
> > > <Bret.Barkelew@microsoft.com>; Kinney, Michael D
> > > <michael.d.kinney@intel.com>
> > > 主题: [RFC V2] Create supported branch from edk2-stable* tag (Required
> to
> > > address critical bug BZ3111)
> > >
> > > Hello,
> > >
> > > The following bug has been fixed on edk2/master
> > >
> > >     https://bugzilla.tianocore.org/show_bug.cgi?id=3111
> > >     https://github.com/tianocore/edk2/pull/1226
> > >
> > > This bug is also considered a critical bug against edk2-stable202011.  The
> > > behavior
> > > of the Variable Lock Protocol was changed in a non-backwards compatible
> > > manner in
> > > edk2-stable202011 and this is impacting some downstream platforms.
> The
> > > following
> > > 2 commits on edk2/master restore the original behavior of the Variable
> Lock
> > > Protocol.
> > >
> > >
> > >
> https://github.com/tianocore/edk2/pull/1226/commits/893cfe2847b83da74f
> > > 53858d6acaa15a348bad7c
> > >
> > >
> https://github.com/tianocore/edk2/pull/1226/commits/16491ba6a6e9a91ce
> > > deeed45bc0fbdfde49f7968
> > >
> > [Liming] This one is for unit test. It is not critical fix. I don't think it is
> required.
> 
> 
> I agree it is not strictly required for functionality, but the bug fix that is
> required
> was reviewed and submitted in a PR as a patch series.  I think critical bug
> fixes should
> be applied to a supported branch at the same granularity they were
> submitted to the
> trunk.  Since the EDK II CI system does not evaluate the stability of each
> patch in
> a patch series, there is a risk to take portions of a patch series.
> 
> I suggest when a critical bug fix is identified, that we start with cherry-picking
> all the patches in the patch series.  If there is a specific concern about taking
> the entire patch series, then that can be discussed and potentially a different
> patch series can be applied to the supported branch.  This would require CI
> on
> supported branch to make sure the quality and functionality are the same.
> 

This case is clear. One commit is for the bug fix, another is for the unit test. 
If the unit test is also important for this fix, it can be cherry-pick. I understand the critical bug fix is for the functionality only.

> >
> > > The request here is to create a supported branch from edk2-stable202011
> tag
> > > and apply
> > > these 2 commits as critical bug fixes on the supported branch.
> > >
> > > Since we started using the edk2-stable* tag process, there has not been a
> > > request to create
> > > a supported branch from one of those tags.  As a result, there are a
> couple
> > > opens that
> > > need to be addressed:
> > >
> > > 1) Supported branch naming convention.
> > >
> > >     Proposal: stable/<YYYY><MM>
> > >     Example:  stable/202011
> > Here is my suggestion on the live period of the stable tag branch.
> > The stable tag branch will be created only when the critical issue is found in
> this stable tag. By default, no stable tag
> > branch is created.
> > Now, the quarterly stable tag will be created every three months. So, this
> branch will exist for at most three months.
> > Once next stable tag is created, new stable tag will be used. Previous stable
> tag branch will not be maintained.
> > That means only latest stable tag branch will be maintained if it is created.
> 
> It is hard to predict how downstream platforms use a stable tag or a
> supported branch.
> If a downstream consumer identifies a critical bug in a previous stable tag or
> a supported branch, then that bug report needs to be evaluated and
> determine if
> the bug fix needs to be applied to a stable branch or not.  I do not think we
> should
> reject all requests just because there is a more recent stable tag.  We need
> to evaluate each request.
> 
If stable branch requires long term maintain, the stable branches will become more and more,
the branch maintain effort will be more and more. It may not be workable in open source edk2 community
unless there is the dedicated branch maintainers.

So, I suggest that downstream consumers maintain their downstream branch to include the hot fix. 
Edk2 stable branch is the reference for the downstream users.

Thanks
Liming
> We do want to encourage all platforms under development to use the latest
> stable
> tag.  But once a platform is released as a product using a specific stable tag
> they may prefer to continue to use that stable tag for long term maintenance
> of that platform.
> 
> >
> > >
> > > 2) CI requirements for supported branches.
> > >
> > >     Proposal: Update .azurepipelines yml files to also trigger on stable/*
> > > branches
> > >     and update GitHub settings so stable/* branches are protected
> > > branches.
> > >
> > The patch has been verified in master. CI test may not be necessary.
> 
> In the general case where more than one critical bug may be fixed in a
> stable branch, CI will help make sure that the combination of fixes
> work together.  For this first case, I agree that CI may not be required.
> 
> >
> > > 3) Release requirements for supported branches.
> > >
> > >    Proposal: If there are a significant number of critical fixes applied to
> > >    a stable/edk2-stable* branch, then a request for a release can be
> made
> > > that
> > >    would trigger focused testing of the supported branch and creation of
> a
> > > new
> > >    release.  If all testing passes, then a tag is created on the
> > > stable/edk2-stable*
> > >    branch and a release is created on GitHub that summarizes the set of
> > > critical
> > >    fixes and the testing performed.
> > >
> > >    Proposal: edk2-stable<YYYY><MM>.<XX>
> > >    Example : edk2-stable201111.01
> > >
> > It is OK to create new stable tag per the request. The platform can use
> stable branch.
> 
> Thank you.  I will start work on a patch for review.
> 
> >
> > Besides, there are few new issues. I have cancelled the bug triage meeting.
> >
> > Thanks
> > Liming
> > > Please let me know if you have any feedback or comments on this
> proposal.
> > > The goal
> > > is to close on this topic this week.
> > >
> > > Thank you,
> > >
> > > Mike
> >