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

[Takashi Iwai <tiwai@suse.de>]

On Wed, 05 Sep 2018 14:24:18 +0200,
James Bottomley wrote:
> 
> On September 5, 2018 11:47:00 AM GMT+01:00, Mark Brown <broonie@kernel.org> wrote:
> >On Wed, Sep 05, 2018 at 10:58:45AM +0100, James Bottomley wrote:
> >
> >> This really shouldn't be an issue: stable trees are backported from
> >> upstream.  The patch (should) work in upstream, so it should work in
> >> stable.  There are only a few real cases you need to worry about:
> >
> >>    1. Buggy patch in upstream backported to stable. (will be caught
> >and
> >>       the fix backported soon)
> >>    2. Missing precursor causing issues in stable alone.
> >>    3. Bug introduced when hand applying.
> >
> >> The chances of one of these happening is non-zero, but the criteria
> >for
> >> stable should mean its still better odds than the odds of hitting the
> >> bug it was fixing.
> >
> >Some of those are substantial enough to be worth worrying about,
> >especially the missing precursor issues.  It's rarely an issue with the
> >human generated backports but the automated ones don't have a sense of
> >context in the selection.
> >
> >There's also a risk/reward tradeoff to consider with more minor issues,
> >especially performance related ones.  We want people to be enthusiastic
> >about taking stable updates and every time they find a problem with a
> >backport that works against them doing that.
> 
> I absolutely agree.  That's why I said our process is expediency
> based:  you have to trade off the value of applying the patch vs the
> probability of introducing bugs.  However the maintainers are mostly
> considering this which is why stable is largely free from trivial
> but pointless patches.  The rule should be: if it doesn't fix a user
> visible bug, it doesn't go into stable.

Right, and here the current AUTOSEL (and some other not-stable-marked)
patches coming to a gray zone.  The picked-up patches are often right
as "some" fixes, but they are not necessarily qualified as "stable
fixes".

How about allowing to change the choice of AUTOSEL to be opt-in and
opt-out, depending on the tree?  In my case, usually the patches
caught by AUTOSEL aren't really the patches with forgotten stable
marker, but rather left intentionally by various reasons.  Most of
them are fine to apply in anyway, but it was uncertain whether they
are really needed / qualifying as stable fixes.  So, I'd be happy to
see them as opt-in, i.e. applied only via manual approval.

Meanwhile, some trees have no stable-maintenance, and AUTOSEL would
help for them.  They can be opt-out, i.e. kept until someone rejects.


thanks,

Takashi