Re: [PATCH v3 2/2] mm: redefine VM_* flag constants with BIT()

[David Hildenbrand]

On 01.10.25 18:51, SeongJae Park wrote:
> On Wed, 1 Oct 2025 09:03:53 +0000 Jakub Acs <acsjakub@xxxxxxxxx> wrote:
>
> > Make VM_* flag constant definitions consistent - unify all to use BIT()
> > macro.
> >
> > This is a separete follow-up fix after we changed VM_MERGEABLE
> > separately to isolate bugfix for easier backporting. As suggested by
> > David in [1].
> >
> > [1]: https://lore.kernel.org/all/85f852f9-8577-4230-adc7-c52e7f479454@xxxxxxxxxx/
> >
> > Signed-off-by: Jakub Acs <acsjakub@xxxxxxxxx>
> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > Cc: David Hildenbrand <david@xxxxxxxxxx>
> > Cc: Xu Xin <xu.xin16@xxxxxxxxxx>
> > Cc: Chengming Zhou <chengming.zhou@xxxxxxxxx>
> > Cc: Peter Xu <peterx@xxxxxxxxxx>
> > Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
> > Cc: linux-mm@xxxxxxxxx
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > ---
> >   include/linux/mm.h | 66 +++++++++++++++++++++++-----------------------
> >   1 file changed, 33 insertions(+), 33 deletions(-)
> >
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index c6794d0e24eb..88cab3d7eea2 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -246,56 +246,56 @@ extern unsigned int kobjsize(const void *objp);
> >    * vm_flags in vm_area_struct, see mm_types.h.
> >    * When changing, update also include/trace/events/mmflags.h
> >    */
> > -#define VM_NONE		0x00000000
> > +#define VM_NONE		0
>
> I'm wondering if it could be more consistent to use 0UL instead.

Not really required, and if we're switching to BIT already there is not 
a lot of consistency to be had. Would be different if we were avoid 
BIT() is in patch v2.

--
Cheers

David / dhildenb