Re: [PATCH] mm/mmap: introduce vma_range_init()

From: Andrew Morton
Date: Mon Jan 22 2024 - 18:40:43 EST


On Mon, 22 Jan 2024 17:00:31 -0500 "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> wrote:

> * Yajun Deng <yajun.deng@xxxxxxxxx> [240110 21:15]:
> > There is a lot of code needs to set the range of vma, introduce
> > vma_range_init() to initialize the range of vma.
> >
> > Signed-off-by: Yajun Deng <yajun.deng@xxxxxxxxx>
> > ---
> > include/linux/mm.h | 9 +++++++++
> > mm/mmap.c | 29 +++++++----------------------
> > 2 files changed, 16 insertions(+), 22 deletions(-)
>
> This isn't a whole lot of code, are there others? We're losing code
> clarity in favour of saving 6 lines?
>

Oh. I thought it was a nice cleanup which made things more clear.

> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index f5a97dec5169..abb4534be3cc 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -3516,6 +3516,15 @@ static inline bool range_in_vma(struct vm_area_struct *vma,
> > return (vma && vma->vm_start <= start && end <= vma->vm_end);
> > }
> >
> > +static inline void vma_range_init(struct vm_area_struct *vma,
>
> Any reason this can't be in mm/internal.h ?

That would be good.

> vma_range_set(), vma_set_range(), or just vma_range() might be a better
> name? My thinking is that some of these are actually modifying the vma
> and not just initializing it, right?

I'd vote for vma_set_range().