Re: [PATCH] MAINTAINERS: group all VMA-related files into the VMA section

[David Hildenbrand <david@redhat.com>]

On 09.12.24 15:38, Jann Horn wrote:
> On Mon, Dec 9, 2024 at 3:11 PM Lorenzo Stoakes
> <lorenzo.stoakes@oracle.com> wrote:
>> On Mon, Dec 09, 2024 at 03:00:08PM +0100, David Hildenbrand wrote:
>>> On 09.12.24 14:25, Vlastimil Babka wrote:
>>>> On 12/9/24 10:16, David Hildenbrand wrote:
>>>>> On 06.12.24 20:16, Lorenzo Stoakes wrote:
>>>>>> There are a number of means of interacting with VMA operations within mm,
>>>>>> and we have on occasion not been made aware of impactful changes due to
>>>>>> these sitting in different files, most recently in [0].
>>>>>>
>>>>>> Correct this by bringing all VMA operations under the same section in
>>>>>> MAINTAINERS. Additionally take the opportunity to combine MEMORY MAPPING
>>>>>> with VMA as there needn't be two entries as they amount to the same thing.
>>>>>>
>>>>>> [0]:https://lore.kernel.org/linux-mm/CAG48ez0siYGB8GP5+Szgj2ovBZAkL6Zi4n6GUAjzzjFV9LTkRQ@mail.gmail.com/
>>>>>>
>>>>>> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
>>>>>> ---
>>>>>>     MAINTAINERS | 19 +++++++------------
>>>>>>     1 file changed, 7 insertions(+), 12 deletions(-)
>>>>>>
>>>>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>>>>> index 1e930c7a58b1..95db20c26f5f 100644
>>>>>> --- a/MAINTAINERS
>>>>>> +++ b/MAINTAINERS
>>>>>> @@ -15060,18 +15060,6 @@ F:     tools/mm/
>>>>>>     F:   tools/testing/selftests/mm/
>>>>>>     N:   include/linux/page[-_]*
>>>>>>
>>>>>> -MEMORY MAPPING
>>>>>> -M:     Andrew Morton <akpm@linux-foundation.org>
>>>>>> -M:     Liam R. Howlett <Liam.Howlett@oracle.com>
>>>>>> -M:     Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
>>>>>> -R:     Vlastimil Babka <vbabka@suse.cz>
>>>>>> -R:     Jann Horn <jannh@google.com>
>>>>>> -L:     linux-mm@kvack.org
>>>>>> -S:     Maintained
>>>>>> -W:     http://www.linux-mm.org
>>>>>> -T:     git git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
>>>>>> -F:     mm/mmap.c
>>>>>> -
>>>>>>     MEMORY TECHNOLOGY DEVICES (MTD)
>>>>>>     M:   Miquel Raynal <miquel.raynal@bootlin.com>
>>>>>>     M:   Richard Weinberger <richard@nod.at>
>>>>>> @@ -25028,6 +25016,13 @@ L:     linux-mm@kvack.org
>>>>>>     S:   Maintained
>>>>>>     W:   https://www.linux-mm.org
>>>>>>     T:   git git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
>>>>>> +F:     mm/madvise.c
>>>>>> +F:     mm/mlock.c
>>>>>> +F:     mm/mmap.c
>>>>>> +F:     mm/mprotect.c
>>>>>> +F:     mm/mremap.c
>>>>>> +F:     mm/mseal.c
>>>>>> +F:     mm/msync.c
>>>>>
>>>>> Not sure about mprotect.c, mlock.c and madvise.c, though. I'd claim that
>>>>> the real "magic" they perform is in page table handling and not
>>>>> primarily VMA handling (yes, both do VMA changes, but they are the
>>>>> "easy" part ;) ).
>>>>
>>>> I'd think that moving vma files into MEMORY MAPPING (and not the other way)
>>>> would result in a better overal name, that would be a better fit for the
>>>> newly added files too?
>>>
>>> Maybe. I think vma.c should likely have a different set of maintainers than
>>> madvise.c and mprotect.c. (again, the magic is in page table modifications)
>>
>> The bulk of the logic in mremap.c is related to page tables so by this
>> logic then, that is out too, right?
> 
> FWIW, I think technically you can have multiple entries in MAINTAINERS
> that cover the same file, maybe that would make sense for files that
> belong to multiple parts of the kernel?

I was asking myself the same question. But then ...

> Or maybe I'm making things too
> complicated and it'd be simpler to have some kind of more generic
> "core MM for userspace mappings" entry or such.

... this sound cleaner than having files as part of every section with 
which they partially overlap.

-- 
Cheers,

David / dhildenb