Re: [PATCH v11 1/8] mm: rust: add abstraction for struct mm_struct

[Lorenzo Stoakes <lorenzo.stoakes@oracle.com>]

On Tue, Jan 14, 2025 at 05:54:15PM -0800, John Hubbard wrote:
> On 1/14/25 7:48 AM, Lorenzo Stoakes wrote:
> > On Mon, Jan 13, 2025 at 10:53:33AM +0100, Alice Ryhl wrote:
> > > On Mon, Dec 16, 2024 at 3:50 PM Andreas Hindborg <a.hindborg@kernel.org> wrote:
> > > > "Alice Ryhl" <aliceryhl@google.com> writes:
> ...
> > > > > +/// [`mmget_not_zero`]: Mm::mmget_not_zero
> > > > > +#[repr(transparent)]
> > > > > +pub struct Mm {
> > > >
> > > > Could we come up with a better name? `MemoryMap` or `MemoryMapping`?. You
> > > > use `MMapReadGuard` later.
> > >
> > > Those names seem really confusing to me. The mmap syscall creates a
> > > new VMA, but MemoryMap sounds like it's the thing that mmap creates.
> > >
> > > Lorenzo, what do you think? I'm inclined to just call it Mm since
> > > that's what C calls it.
> >
> > I think Mm is better just for aligment with the C stuff, I mean the alternative
> > is MmStruct or something and... yuck.
>
> For what it's worth, I think using the C naming here is a very good approach.
> Because if you come up with a "good" name that is different than what C has
> been calling it for 30+ years, then we have to be very thorough in associating
> that new name with the C name. And it's hard.

100% agree!

>
> And "mm struct" goes waaay back. Just use that name and everyone will know
> what it means.
>
> For less well-established areas, with fewer callers, there is much more
> freedom to come up with new, better names.
>
> >
> > And like, here I am TOTALLY onboard with Andreas here, because this naming
> > SUCKS. But it sucks on the C side too (we're experts at bad naming :). So for
> > consistency, let's suck everywhere...
> >
> > Feel free to put a comment about this being a bad name if you like
> > though... (not obligatory :)
>
> For mm struct? Maybe let's not! Explanation without the criticism seems
> more appropriate imho. :)

;) Well one could phrase this in a relatifvely benign way for instance 'while
 this name may seem a little unclear, historically it has been used as a
 shorthand within the kernel for time immemorial' or such.

>
> btw, I'm very excited to see all of this Rust for Linux progress, it is
> wonderful! Thank you for this!

+1 to this sentiment, am very happy to try to do my best to add value to get
this series in as - from my perspective - I want the compiler to tell me when I
make mistakes nice and early :))

Thanks Alice, Andreas and all involved!

>
>
> thanks,
> --
> John Hubbard
>