Re: [PATCH v3 1/4] mm: Introduce vm_uffd_ops API

David Hildenbrand
2025-10-06T13:38:12Z

Hi Peter,

>>
>> Agreed, while making the API cleaner. I don't easily see what's confusing
>> about that, though.
>
> It will introduce another set of userfaultfd features, making it hard to
> say what is the difference between the new set and UFFD_FEATURE_*.

That's why I suggested we use something like "BACKEND" as part of the name.

If we can come up with something better, like talking about capabilities
than features to better distinguish it, even better (UFFD_BACKEND_CAP_*
etc).

>
>>
>> I think it can be done with a handful of LOC and avoid having to use VM_
>> flags in this API.
>
> I waited for a few days, unfortunately we didn't get a second opinion.
>

We are currently in the merge window and many people are either out or
were attending kernel recipes and are on their way back.

I'd suggest waiting a couple of days for more feedback -- right now
there is no need to rush either way, we have the complete development
cycle starting in one week.

--
Cheers

David / dhildenb