[Ksummit-discuss] [MAINTAINER SUMMIT] Stable trees and release time

[Laura Abbott]

On 09/05/2018 07:42 AM, Greg KH wrote:
> On Tue, Sep 04, 2018 at 04:22:59PM -0500, Justin Forbes wrote:
>> On Tue, Sep 4, 2018 at 3:58 PM, Laura Abbott <labbott at redhat.com> wrote:
>>> I'd like to start a discussion about the stable release cycle.
>>>
>>> Fedora is a heavy user of the most recent stable trees and we
>>> generally do a pretty good job of keeping up to date. As we
>>> try and increase testing though, the stable release process
>>> gets to be a bit difficult. We often run into the problem where
>>> release .Z is officially released and then .Z+1 comes
>>> out as an -rc immediately after. Given Fedora release processes,
>>> we haven't always finished testing .Z by the time .Z+1 comes
>>> out. What to do in this situation really depends on what's in
>>> .Z and .Z+1 and how stable we think things are. This usually
>>> works out fine but a) sometimes we guess wrong and should have
>>> tested .Z more b) we're only looking to increase testing.
>>>
>>> What I'd like to see is stable updates that come on a regular
>>> schedule with a longer -rc interval, say Sunday with
>>> a one week -rc period. I understand that much of the current
>>> stable schedule is based on Greg's schedule. As a distro
>>> maintainer though, a regular release schedule with a longer
>>> testing window makes it much easier to plan and deliver something
>>> useful to our users. It's also a much easier sell for encouraging
>>> everyone to pick up every stable update if there's a known
>>> schedule. I also realize Greg is probably reading this with a very
>>> skeptical look on his face so I'd be interested to hear from
>>> other distro maintainers as well.
>>>
>>
>> This has been a fairly recent problem. There was a roughly weekly
>> cadence for a very long time and that was pretty easy to work with.  I
>> know that some of these updates do fix embargoed security issues that
>> we don't find out are actual fixes until later, but frequently in
>> those cases, the fixes are pushed well before embargo lifts, and they
>> could be fit into a weekly cadence.  Personally I don't have a problem
>> with the 3 day rc period, but pushing 2 kernels a week can be a
>> problem for users. (skipping a stable update is also a problem for
>> users.)  What I would prefer is 1 stable update per week with an
>> exception for *serious* security issues, where serious would mean
>> either real end user impact or high profile lots of press users are
>> going to be wondering where a fix is.
> 
> Laura, thanks for bringing this up.  I'll try to respond here given that
> Justin agrees with the issue of timing.
> 
> Honestly, this year has been a total shit-storm for stable due to the
> whole security mess we have been dealing with.  The number of
> totally-crazy-intrusive patches I have had to take is insane.  Combine
> that with a total lack of regard for the security issues for some arches
> (arm32 comes to mind), it's been a very rough year and I have been just
> trying to keep on top of everything.
> 
> Because of these issues (and it wasn't just spectre/meltdown, we have
> had other major fire drills in some subsystems), the release cycles have
> been quick and contain a lot of patches, sorry about that.  But that is
> reflected in Linus's tree as well, so maybe this is just the "new
> normal" that we all need to get used to.
> 

While the specdown stuff was bad, I was seeing this pattern well
before all that happened as well. I do agree this may be a new normal
which is why I brought up the discussion topic.

> I could do a "one release a week" cycle, which I would _love_ but that
> is not going to decrease the number of patches per release, it is only
> going to make them large (patch rate stays the same, and increases, no
> matter when I release)  So I had been thinking that to break the
> releases up into a "here's a hundred or so patches" per release, was a
> helpful thing to the reviewers.
I'm really not that concerned with the number of patches going in.
We'll be testing if there's 1 or 300 patches and trying to pick
and choose tests also doesn't work. Stable updates that contain
a headline making bug can be handled differently.

> If this assumption is incorrect, yes, I can go to one-per-week, if
> people agree that they can handle the large increase per release
> properly.  Can you all do that?
> 
> Are we going to do a "patch tuesday" like our friends in Redmond now? :)
> > Note, if we do pick a specific day-per-week, then anything outside of
> that cycle will cause people to look _very_ close at the release.  I
> don't know if that's a good thing or not, but be aware that it could
> cause unintended side-affects.  Personally I think the fact that we are
> _not_ regular is a good thing, no out-of-band information leakage
> happens that way.
> 

There's certainly trade offs to be made. A side-channel for our
side-channel patches could be bad but most people who are seriously
interested are looking already.

Thanks,
Laura

> thanks,
> 
> greg k-h
>