Re: bug-introducing patches

[Geert Uytterhoeven]

On Tue, May 1, 2018 at 10:00 PM, Sasha Levin
<Alexander.Levin@xxxxxxxxxxxxx> wrote:
> On Tue, May 01, 2018 at 03:44:50PM -0400, Theodore Y. Ts'o wrote:
>>On Tue, May 01, 2018 at 04:38:21PM +0000, Sasha Levin wrote:
>>>  - A merge window commit spent 50% more days, on average, in -next than a -rc
>>>    commit.
>>
>>So it *used* to be the case that after the merge window, I would queue
>>up bug fixes for the next merge window.  Greg K-H pushed for me to
>>send them to Linus sooner, instead of waiting for the next merge
>>window.  TBH, it's actually easier for me to just wait until the next
>>merge window, but please understand that there are multiple pressures
>>on maintainers going on here, and the latest efforts to try to use
>>AUTOSEL is just the most recent pressure placed on maintainers.
>>
>>The other thing is that when there is a regression users who are
>>testing linux-next want it fixed *fast*.  That's considered more
>>important to them than waiting for one, perfect patch, just to keep
>>AUTOSEL happy.
>>
>>So please understand that when you say that maintainers *need* to do X
>>or Y, that there you are not the only one standing in line putting
>>pressures on maintainers saying they *need* to do something.  And
>>quite frankly, I consider keeping people who are nice enough to test
>>linux-next happy to be **far** more important than AUTOSEL.
>
> Ted,
>
> I'm not at all asking to wait before adding the patches to your tree,
> or to -next. I'm asking to hold on to them a bit longer before you
> push them to Linus because I can show that patches that don't spend
> enough time in -next are more likely to introduce bugs.
>
> Yes, linux-next users want it fixed *now* and I completely agree it
> should be done that way, but the fix should not be immediately pushed to
> Linus as well.
>
> I've just finished reading an interesting article on LWN about the
> PostgreSQL fsync issues (https://lwn.net/Articles/752952/). If you
> look at Willy's commit, he wrote the final version of it about 5 days
> ago, Jeff merged it in 3 days ago, and Linus merged it in the tree
> today. Did it spend any time getting -next testing? nope.
>
> What's worse is that that commit is tagged for stable, which means
> that (given Greg's schedule) it may find it's way to -stable users
> even before some -next users/bots had a chance to test it out.

I just noticed a case where a commit was picked up for stable, while a
bot had flagged it as a build regression 18 hours earlier (with a CC to
lkml).

So it looks like the script for backporting commits should be enhanced to
check for this (searching for the commit ID in my email archive found the
bot report).

Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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