Re: [PATCH v4 0/4] mm/userfaultfd: modulize memory types

From: David Hildenbrand (Red Hat)
Date: Mon Nov 03 2025 - 15:01:20 EST


I have an extremely heavy workload at the moment anyway, but honestly
interactions like this have seriously put me off being involved in this review
personally.

Do we really want this to be how review in mm or the kernel is?

Is that really the culture we want to have here?

Gosh.. Seriously?

I'm ok if this needs to be audited. I have all the previous discussions in
the cover letter as links.

I'm late to the party (or whatever this here is called. ah right, drama), and I haven't yet dug through all the emails and certainly not through all the of involved code changes.

Peter, I was a bit surprised by your messages here indeed, not what I expected.

The "Your code allows to operate on pmd* in a module??? That's too risky and mm can explode! Isn't it?" definitely was absolutely unnecessary ... or telling Liam that "he want almost mad".

Again, not what I would have expected from you, and I would assume that you had a bad day and would at least apologize now that some time passed.

I understand that you were upset by the previous feedback on the earlier series.

There were some heated arguments in the last discussions, but most of them were based on misunderstandings. I would have thought that once they were resolved that we could continue focusing on discussing the technical details again.

From what I can see you asked for actual code and when Liam came back with some code that looks like *a lot of work* to me.

He really seems to care (which I highly appreciate) and went the extra mile to show us how the uffd code could evolve.

We've all (well okay, some of us) been crying for some proper userfaultfd cleanups for years.

So is there a way we can move forward with this without thinking in binary? Is there some middle-ground to be had? Can some reworks come on top of your series? Can so reworks be integrated in this series?

I agree that what Liam proposes here is on the larger side, and probably does a lot of things in a single rework. That doesn't mean that we couldn't move into that direction in smaller steps.


(I really don't think we should be thinking in terms of a CoC war like: show them what I did and I will show them what they did. We are all working on the same bigger goal here after all ...)

--
Cheers

David