Re: [Ksummit-discuss] bug-introducing patches

[Justin Forbes <jmforbes@linuxtx.org>]

On Mon, May 7, 2018 at 9:34 PM, Sasha Levin
<Alexander.Levin@microsoft.com> wrote:
> On Thu, May 03, 2018 at 04:09:05PM -0700, Tony Lindgren wrote:
>>* Mark Brown <broonie@kernel.org> [180503 22:44]:
>>> On Wed, May 02, 2018 at 08:52:29PM -0700, Guenter Roeck wrote:
>>>
>>> > As for -next, me and others stopped reporting bugs in it, because when we do
>>> > we tend to get flamed for the "noise". Is anyone aware (or cares) that mips
>>> > and nds32 images don't build ? Soaking clothes in an empty bathtub won't make
>>> > them wet, and bugs in code which no one builds, much less tests or uses, won't
>>> > be found.
>>>
>>> You've been flamed for testing -next?  That's not been my experience and
>>> frankly it's pretty horrifying that it's happening.  Testing is pretty
>>> much the whole point of -next existing in the first place so you have to
>>> wonder why people are putting their trees there if they don't want
>>> testing.  I have seen a few issues with people reporting bugs on old
>>> versions of -next but otherwise...
>>
>>Yes I agree testing Linux next is very important. That's the best way for
>>maintainers to ensure a usable -rc1 after a merge window. And then for
>>the -rc cycle, there not much of need for chasing bugs to get things working.
>>
>>Bugs reported for Linux next often seem to get fixed or reverted faster
>>compared to the -rc cycle too. I think that's because people realize that
>>their code will not get merged until it's been fixed.
>>
>>So some daily testing of Linux next can save a lot scrambling after the
>>merge window :)
>>
>>Users don't usually upgrade kernels until after later -rc releases or only
>>after major releases so that probably explains some of the -rc cycle fixes.
>
> Tony, I'm curious, how many users are you aware of who actually run
> Linus's tree? All the users I've encountered so far on Azure seem to be
> running something based on -stable.

I couldn't tell you the number of users we have running rawhide
kernels (daily builds of Linus's tree), but it is a positive integer.
We do get bug reports on things, sometimes a day after Linus commits
them.

>
> I can't really get any solid statistics about that on my end both
> because I don't have visibility inside user VMs (I don't actually have
> prod access believe it or not), and even if I had it would probably be
> confidential, so I'm just basing this on reports from user's I've seen
> so far.
>
> I think that a question we should be asking ourselves is whether we
> should be basing our decisions here on the assumption that (pretty much)
> no one runs Linus's tree anymore?