Re: [Ksummit-discuss] [CORE TOPIC] stable workflow

[Jani Nikula <jani.nikula@intel.com>]

On Wed, 03 Aug 2016, "Rafael J. Wysocki" <rjw@rjwysocki.net> wrote:
> On Tuesday, August 02, 2016 04:34:00 PM Mark Brown wrote:
>> On Tue, Aug 02, 2016 at 05:12:47PM +0300, Jani Nikula wrote:
>> 
>> > Generally adding cc: stable is like, this is clearly a fix to a bug that
>> > is present in stable kernels, and the bug should be fixed, but I have no
>> > idea nor resources to review or test if this is the right fix across all
>> > stable kernels. You end up relying on your gut feeling too much to be
>> > comfortable. You have to make the call too early in the process.
>> 
>> I think the problems here are more in the process of how things go from
>> being tagged stable to appearing in a stable release - the QA or lack
>> thereof and so on.  While I do share some of your misgivings here I do
>> also really like the fact that it's really easy for people to push
>> things out for the attention of those working on backports.  It's
>> essentially the same as the question I often find myself asking people
>> who don't upstream - "why would this fix not benefit other users?".
>
> Agreed, and I think that's exactly where the expectations don't match what's
> delivered in the long-term-stable trees.
>
> It should be made clear that "stable" doesn't mean "no regressions".  What
> it reall means is "hey, if you care about backports, this is the stuff to take
> into consideration in the first place".

I think this interpretation matches reality better than what
Documentation/stable_kernel_rules.txt leads you to believe about adding
cc: stable tag.

However, I presume maintainers don't add cc: stable lightly, even when
the fix could benefit stable kernel users, if there's any risk of the
backport coming back to haunt you. I believe maintainers assume some
degree of responsibility for the backport when they add cc: stable, even
when they don't have the means to do QA. (And with the plethora of
longterm kernels around these days, who does?)

But does being more liberal in adding cc: stable tags and shifting the
responsibility for backports towards stable kernel maintainers work
either? The bugs will anyway be reported to subsystem/driver
maintainers, not stable maintainers.

Side note, I think it would be helpful to be allowed to revert clearly
broken stable kernel backports even without an accompanying mainline
revert. The original commit might be perfectly fine upstream, while the
backport is bogus.


BR,
Jani.

-- 
Jani Nikula, Intel Open Source Technology Center