Den 19.04.2018 kl. 18:57, skrev Greg KH:
On Thu, Apr 19, 2018 at 06:16:26PM +0300, Thomas Backlund wrote:
Den 19.04.2018 kl. 17:22, skrev Greg KH:
On Thu, Apr 19, 2018 at 04:05:45PM +0200, Jan Kara wrote:
On Thu 19-04-18 15:59:43, Greg KH wrote:
On Thu, Apr 19, 2018 at 02:41:33PM +0300, Thomas Backlund wrote:
Den 16-04-2018 kl. 19:19, skrev Sasha Levin:
On Mon, Apr 16, 2018 at 12:12:24PM -0400, Steven Rostedt wrote:
On Mon, 16 Apr 2018 16:02:03 +0000
Sasha Levin <Alexander.Levin@xxxxxxxxxxxxx> wrote:
One of the things Greg is pushing strongly for is "bug compatibility":
we want the kernel to behave the same way between mainline and stable.
If the code is broken, it should be broken in the same way.
Wait! What does that mean? What's the purpose of stable if it is as
broken as mainline?
This just means that if there is a fix that went in mainline, and the
fix is broken somehow, we'd rather take the broken fix than not.
In this scenario, *something* will be broken, it's just a matter of
what. We'd rather have the same thing broken between mainline and
stable.
Yeah, but _intentionally_ breaking existing setups to stay "bug compatible"
_is_ a _regression_ you _really_ _dont_ want in a stable
supported distro. Because end-users dont care about upstream breaking
stuff... its the distro that takes the heat for that...
Something "already broken" is not a regression...
As distro maintainer that means one now have to review _every_ patch that
carries "AUTOSEL", follow all the mail threads that comes up about it, then
track if it landed in -stable queue, and read every response and possible
objection to all patches in the -stable queue a second time around... then
check if it still got included in final stable point relase and then either
revert them in distro kernel or go track down all the follow-up fixes
needed...
Just to avoid being "bug compatible with master"
I've done this "bug compatible" "breakage" more than the AUTOSEL stuff
has in the past, so you had better also be reviewing all of my normal
commits as well :)
Anyway, we are trying not to do this, but it does, and will,
occasionally happen.
Sure, that's understood. So this was just misunderstanding. Sasha's
original comment really sounded like "bug compatibility" with current
master is desirable and that made me go "Are you serious?" as well...
As I said before in this thread, yes, sometimes I do this on purpose.
And I guess this is the one that gets people the feeling that
"stable is not as stable as it used to be" ...
It's always been this way, it's just that no one noticed :)
:)
As an specific example, see a recent bluetooth patch that caused a
regression on some chromebook devices. The chromeos developers
rightfully complainied, and I left the commit in there to provide the
needed "leverage" on the upstream developers to fix this properly.
Otherwise if I had reverted the stable patch, when people move to a
newer kernel version, things break, and no one remembers why.
I do understand what you are trying to do...
But from my distro hat on I have to treat things differently (and I dont
think I'm alone doing it this way...)
Known breakages gets reverted even before it hits QA, so endusers wont see
the issue at all...
So the only ones to see the issue are those building with latest upstream
without own patches applied...
I also wrote a long response as to _why_ I do this, and even though it
does happen, why it still is worth taking the stable updates. Please
see the archives for the full details. I don't want to duplicate this
again here.
And we do use latest stable (with some delay as I dont want to overload QA &
endusers with a new kernel every week :))
You need to automate your QA :)
Yeah, some can be automated... but that means having a lot of different
hw to test on... emulators/vms can only test so much...
users part of QA test on a variety of hw with various installs/setups
that exposes fun things with some hw :)
We just revert known broken (or add known fixes) before releasing them to
our users
That's great, and is what you should be doing, nothing wrong there.
thanks,
greg k-h
--
Thomas