Re: [PATCH v2 2/2] mm: madvise: no-op for MADV_NOHUGEPAGE if THP is disabled

["Liam R. Howlett" <Liam.Howlett@oracle.com>]

* Ignacio Moreno Gonzalez via B4 Relay <devnull+Ignacio.MorenoGonzalez.kuka.com@kernel.org> [250506 09:44]:
> From: Ignacio Moreno Gonzalez <Ignacio.MorenoGonzalez@kuka.com>
> 
> VM_NOHUGEPAGE is a no-op in a kernel without THP. So it makes no sense
> to return an error when calling madvise() with MADV_NOHUGEPAGE.
> 
> Suggested-by: Matthew Wilcox <willy@infradead.org>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> Reviewed-by: Yang Shi <yang@os.amperecomputing.com>
> Signed-off-by: Ignacio Moreno Gonzalez <Ignacio.MorenoGonzalez@kuka.com>

Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>

> ---
>  include/linux/huge_mm.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index e893d546a49f464f7586db639fe216231f03651a..cdb991f9be918182f94003394cf793654a080224 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -7,6 +7,10 @@
>  #include <linux/fs.h> /* only for vma_is_dax() */
>  #include <linux/kobject.h>
>  
> +#ifndef CONFIG_TRANSPARENT_HUGEPAGE
> +#include <uapi/asm-generic/mman-common.h>
> +#endif
> +
>  vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf);
>  int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
>  		  pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
> @@ -598,6 +602,8 @@ static inline bool unmap_huge_pmd_locked(struct vm_area_struct *vma,
>  static inline int hugepage_madvise(struct vm_area_struct *vma,
>  				   unsigned long *vm_flags, int advice)
>  {
> +	if (advice == MADV_NOHUGEPAGE)
> +		return 0;
>  	return -EINVAL;
>  }
>  
> 
> -- 
> 2.39.5
> 
>