On 16.06.20 06:08, Anshuman Khandual wrote:
> zero_pfn variable is required whether __HAVE_COLOR_ZERO_PAGE is enabled
Why is that relevant for this patch?
> or not. Also it should not really be declared individually in all functions
> where it gets used. Just move the declaration outside, which also makes it
> available for other potential users.
So, all you're essentially doing is exposing zero_pfn in pgtable.h now.
If everybody should just use my_zero_pfn(), I don't really see the
benefit of this patch, sorry.
>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: linux-arch@xxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
> Applies on 5.8-rc1. If the earlier motivation was to hide zero_pfn from
> general visibility, we could just put in a comment and update the commit
> message that my_zero_pfn() should always be used rather than zero_pfn.
> Build tested on many platforms and boot tested on arm64, x86.
>
> include/linux/pgtable.h | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> index 32b6c52d41b9..078e9864abca 100644
> --- a/include/linux/pgtable.h
> +++ b/include/linux/pgtable.h
> @@ -1020,10 +1020,11 @@ extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
> extern void untrack_pfn_moved(struct vm_area_struct *vma);
> #endif
>
> +extern unsigned long zero_pfn;
> +
> #ifdef __HAVE_COLOR_ZERO_PAGE
> static inline int is_zero_pfn(unsigned long pfn)
> {
> - extern unsigned long zero_pfn;
> unsigned long offset_from_zero_pfn = pfn - zero_pfn;
> return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
> }
> @@ -1033,13 +1034,11 @@ static inline int is_zero_pfn(unsigned long pfn)
> #else
> static inline int is_zero_pfn(unsigned long pfn)
> {
> - extern unsigned long zero_pfn;
> return pfn == zero_pfn;
> }
>
> static inline unsigned long my_zero_pfn(unsigned long addr)
> {
> - extern unsigned long zero_pfn;
> return zero_pfn;
> }
> #endif
>
--
Thanks,
David / dhildenb
