Re: [PATCH v3 mm 2/2] mm: vm_insert_pages() checks if pte_index defined.

[Soheil Hassas Yeganeh <soheil@google.com>]

On Fri, Feb 28, 2020 at 8:38 AM Jason Gunthorpe <jgg@ziepe.ca> wrote:
>
> On Thu, Feb 27, 2020 at 09:47:14PM -0800, Arjun Roy wrote:
> > diff --git a/mm/memory.c b/mm/memory.c
> > index d6f834f7d145..47b28fcc73c2 100644
> > +++ b/mm/memory.c
> > @@ -1460,18 +1460,6 @@ static int insert_page_into_pte_locked(struct mm_struct *mm, pte_t *pte,
> >       return 0;
> >  }
> >
> > -static int insert_page_in_batch_locked(struct mm_struct *mm, pmd_t *pmd,
> > -                     unsigned long addr, struct page *page, pgprot_t prot)
> > -{
> > -     int err;
> > -
> > -     if (!page_count(page))
> > -             return -EINVAL;
> > -     err = validate_page_before_insert(page);
> > -     return err ? err : insert_page_into_pte_locked(
> > -             mm, pte_offset_map(pmd, addr), addr, page, prot);
> > -}
> > -
> >  /*
> >   * This is the old fallback for page remapping.
> >   *
> > @@ -1500,8 +1488,21 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr,
> >       return retval;
> >  }
> >
> > +#ifdef pte_index
>
> It seems a bit weird like this, don't we usually do this kind of stuff
> with some CONFIG_ARCH_HAS_XX thing?
>
> IMHO all arches should implement pte_index as the static inline, that
> has been the general direction lately.

Based on a comment from Stephen Rothwell, we found out that "static
inline" functions are only used in tile and x86.  That's why Arjun
opted for this method to create a smaller patch-series to fix the
build breakage.

Thanks,
Soheil

> Jason