Re: linus-next: improving functional testing for to-be-merged pull requests

Geert Uytterhoeven
2024-10-29T08:20:35Z

Hi Sasha,

On Mon, Oct 28, 2024 at 11:46 PM Sasha Levin <sashal@kernel.org> wrote:
> On Mon, Oct 21, 2024 at 11:48:34PM -0700, Christoph Hellwig wrote:
> >On Mon, Oct 21, 2024 at 09:54:53PM -0700, Kees Cook wrote:
> >> For example, for a given PR, the bot can report:
> >>
> >> - Were the patches CCed to a mailing list?
> >> - A histogram of how long the patches were in next (to show bake times)
> >> - Are any patches associated with test failures? (0day and many other
> >> CIs are already running tests against -next; parse those reports)
> >>
> >> We could have a real pre-submit checker! :)
> >
> >That would be very useful. Items 1 and 2 should be trivial, 3 would
> >require a bit of work but would still be very useful.
>
> If you've been following so far, there is a bot that is capable of doing
> most of the above
> (https://git.kernel.org/pub/scm/linux/kernel/git/sashal/next-analysis.git/).
>
> Here's a histogram that describes v6.12-rc4..v6.12-rc5 as far as how
> long commits spent in -next:
>
> Days in linux-next:
> ----------------------------------------
> 0 | +++++++++++++++++++++++++++++++++++++++++++++++++ (89)
> <1 | +++++++++++ (21)
> 1 | +++++++++++ (21)
> 2 | +++++++++++++++++++++++++ (45)
> 3 | ++++++++++++++ (25)
> 4 | +++++ (10)
> 5 |
> 6 | + (2)
> 7 |
> 8 | + (3)
> 9 | ++ (4)
> 10 |
> 11 | +++ (6)
> 12 |
> 13 |
> 14+| ++++++++ (15)
>
> This is where I think the value of linus-next comes during the -rc
> cycles: the (89 + 21) commits that haven't gone through the -next
> workflow before being pulled. I'm not looking to delay the process and
> add latency, I'm looking to plug a hole where code would flow directly
> to Linus's tree bypassing -next.
>
> With linus-next, we can at least squeeze in build tests as well as some
> rudimentary testing if we get a few hours before Linus pulls (and we
> usually do).

[Oops, I misread "linus-next"-with-an-S in the last two paragraphs,
and only noticed _after_ I wrote my comments below. Anyway, I am
still sending them as they (partly) explain the histogram's shape.]

Linux-next releases are not created automatically.
The last linux-next release happens on Friday (AU time), while Linus
creates the -rc on Sunday (US time), so most PRs sent during the second
half of the week would miss linux-next until Monday...

"Release early" still matters...

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds