On Thu, Apr 21, 2022 at 01:02:25PM -0700, Andrew Morton wrote:
> On Thu, 21 Apr 2022 15:51:03 -0400 Peter Xu <peterx@redhat.com> wrote:
> 
> > > - * file-backed memory.  This should only be specified when we will completely
> > > - * drop the page in the mm, either by truncation or unmapping of the vma.  By
> > > - * default, the flag is not set.
> > > - */
> > > -#define  ZAP_FLAG_DROP_MARKER        ((__force zap_flags_t) BIT(0))
> > > -
> > >  #endif /* _LINUX_MM_H */
> > > _
> > > 
> > 
> > Andrew,
> > 
> > It may work, but I have worry that zap_flags_t should still be a common
> > struct for mm not hugetlb specific, let's say it's still legal some .c file
> > wants to reference it without hugetlb knowledge?
> > 
> > >From that POV, could we perhaps move these chunk into mm_types.h (which
> > hugetlb.h includes anyway)?
> > 
> 
> Sure.  ZAP_FLAG_DROP_MARKER isn't a type so how about we leave that in
> mm.h?

Sounds good, thanks!

> 
> 
> --- a/include/linux/mm.h~mm-hugetlb-only-drop-uffd-wp-special-pte-if-required-fix-fix
> +++ a/include/linux/mm.h
> @@ -3431,8 +3431,6 @@ madvise_set_anon_name(struct mm_struct *
>  }
>  #endif
>  
> -typedef unsigned int __bitwise zap_flags_t;
> -
>  /*
>   * Whether to drop the pte markers, for example, the uffd-wp information for
>   * file-backed memory.  This should only be specified when we will completely
> --- a/include/linux/mm_types.h~mm-hugetlb-only-drop-uffd-wp-special-pte-if-required-fix-fix
> +++ a/include/linux/mm_types.h
> @@ -850,4 +850,6 @@ enum fault_flag {
>  	FAULT_FLAG_ORIG_PTE_VALID =	1 << 11,
>  };
>  
> +typedef unsigned int __bitwise zap_flags_t;
> +
>  #endif /* _LINUX_MM_TYPES_H */
> _
> 

-- 
Peter Xu