Subject: Re: linux-next: manual merge of the vfs-brauner tree with the mm tree

From: Stephen Rothwell <[email-masked]>
Date: Wed, 18 Sep 2024 10:34:12 +1000

Hi all,

On Mon, 2 Sep 2024 11:21:01 +1000 Stephen Rothwell <[email-masked]> wrote:
>
> Today's linux-next merge of the fs-next tree got a conflict in:
> 
>   include/linux/huge_mm.h
> 
> between commit:
> 
>   bc47772ebe8b ("mm: introduce a pageflag for partially mapped folios")
> 
> from the mm-unstable branch of the mm tree and commit:
> 
>   fd031210c9ce ("mm: split a folio in minimum folio order chunks")
> 
> from the vfs-brauner tree.
> 
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging.  You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
> 
> diff --cc include/linux/huge_mm.h
> index 0b0539f4ee1a,7c50aeed0522..000000000000
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@@ -326,14 -316,15 +328,15 @@@ unsigned long thp_get_unmapped_area_vmf
>   		unsigned long len, unsigned long pgoff, unsigned long flags,
>   		vm_flags_t vm_flags);
>   
>  -bool can_split_folio(struct folio *folio, int *pextra_pins);
>  +bool can_split_folio(struct folio *folio, int caller_pins, int *pextra_pins);
>   int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
>   		unsigned int new_order);
> + int split_folio_to_list(struct folio *folio, struct list_head *list);
>   static inline int split_huge_page(struct page *page)
>   {
> - 	return split_huge_page_to_list_to_order(page, NULL, 0);
> + 	return split_folio(page_folio(page));
>   }
>  -void deferred_split_folio(struct folio *folio);
>  +void deferred_split_folio(struct folio *folio, bool partially_mapped);
>   
>   void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
>   		unsigned long address, bool freeze, struct folio *folio);
> @@@ -502,7 -487,13 +505,13 @@@ static inline int split_huge_page(struc
>   {
>   	return 0;
>   }
> + 
> + static inline int split_folio_to_list(struct folio *folio, struct list_head *list)
> + {
> + 	return 0;
> + }
> + 
>  -static inline void deferred_split_folio(struct folio *folio) {}
>  +static inline void deferred_split_folio(struct folio *folio, bool partially_mapped) {}
>   #define split_huge_pmd(__vma, __pmd, __address)	\
>   	do { } while (0)
>   

This is now a conflict between the vfs-brauner tree and the mm-stable
tree.

-- 
Cheers,
Stephen Rothwell