On Mon, Feb 27, 2023 at 10:06:32AM -0800, Eric Biggers wrote:
On Mon, Feb 27, 2023 at 09:47:48AM -0800, Eric Biggers wrote:
Of course, it's not just me that AUTOSEL isn't working for. So, you'll still continue backporting random commits that I have to spend hours bisecting, e.g. https://lore.kernel.org/stable/20220921155332.234913-7-sashal@kernel.org.
But at least I won't have to deal with this garbage for my own commits.
Now, I'm not sure I'll get a response to this --- I received no response to my last AUTOSEL question at https://lore.kernel.org/stable/Y1DTFiP12ws04eOM@sol.localdomain. So to hopefully entice you to actually do something, I'm also letting you know that I won't be reviewing any AUTOSEL mails for my commits anymore.
The really annoying thing is that someone even replied to your AUTOSEL email for that broken patch and told you it is broken (https://lore.kernel.org/stable/d91aaff1-470f-cfdf-41cf-031eea9d6aca@mailbox....), and ***you ignored it and applied the patch anyway***.
Why are you even sending these emails if you are ignoring feedback anyway?
I obviously didn't ignore it on purpose, right?
I don't know, is it obvious? You've said in the past that sometimes you'd like to backport a commit even if the maintainer objects and/or it is known buggy. https://lore.kernel.org/stable/d91aaff1-470f-cfdf-41cf-031eea9d6aca@mailbox.... also didn't explicitly say "Don't backport this" but instead "This patch has issues", so maybe that made a difference?
From what I gather I missed the reply - I would not blindly ignore a maintainer.
Anyway, the fact is that it happened. And if it happened in the one bug that I happened to look at because it personally affected me and I spent hours bisecting, it probably is happening in lots of other cases too. So it seems the process is not working...
This one is tricky, becuase we also end up taking a lot of commits that do fix real bugs, and were never tagged for stable or even had a fixes tag.
Maybe I should run the numbers again, but when we compared regression rates of stable tagged releases and AUTOSEL ones, it was fairly identical.
Separately from responses to the AUTOSEL email, it also seems that you aren't checking for any reported regressions or pending fixes for a commit before backporting it. Simply searching lore for the commit title https://lore.kernel.org/all/?q=%22drm%2Famdgpu%3A+use+dirty+framebuffer+help... would have turned up the bug report https://lore.kernel.org/dri-devel/20220918120926.10322-1-user@am64/ that bisected a regression to that commit, as well as a patch that Fixes that commit: https://lore.kernel.org/all/20220920130832.2214101-1-alexander.deucher@amd.c... Both of these existed before you even sent the AUTOSEL email!
I would love to have a way to automatically grep lore for reported issues that are pinpointed to a given commit. I'm hoping that Thorsten's regression tracker could be used that way soon enough.
So to summarize, that buggy commit was backported even though:
- There were no indications that it was a bug fix (and thus potentially suitable for stable) in the first place.
- On the AUTOSEL thread, someone told you the commit is broken.
- There was already a thread that reported a regression caused by the commit. Easily findable via lore search.
- There was also already a pending patch that Fixes the commit. Again easily findable via lore search.
So it seems a *lot* of things went wrong, no? Why? If so many things can go wrong, it's not just a "mistake" but rather the process is the problem...
BTW, another cause of this is that the commit (66f99628eb24) was AUTOSEL'd after only being in mainline for 4 days, and *released* in all LTS kernels after only being in mainline for 12 days. Surely that's a timeline befitting a critical security vulnerability, not some random neural-network-selected commit that wasn't even fixing anything?
I would love to have a mechanism that tells me with 100% confidence if a given commit fixes a bug or not, could you provide me with one?
w.r.t timelines, this is something that was discussed on the mailing list a few years ago where we decided that giving AUTOSEL commits 7 days of soaking time is sufficient, if anything changed we can have this discussion again.
Note, however, that it's not enough to keep pointing at a tiny set and using it to suggest that the entire process is broken. How many AUTOSEL commits introduced a regression? How many -stable tagged ones did? How many bugs did AUTOSEL commits fix?