Re: [PATCH] mm/thp: make set_huge_zero_page() return void
From: Kirill A. Shutemov
Date: Tue Oct 01 2019 - 07:52:43 EST
On Mon, Sep 30, 2019 at 12:55:28PM -0700, Ralph Campbell wrote:
> The return value from set_huge_zero_page() is never checked so simplify
> the code by making it return void.
>
> Signed-off-by: Ralph Campbell <rcampbell@xxxxxxxxxx>
> ---
> mm/huge_memory.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index c5cb6dcd6c69..6cf0ee65538d 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -686,20 +686,18 @@ static inline gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma)
> }
>
> /* Caller must hold page table lock. */
> -static bool set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
> +static void set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
> struct vm_area_struct *vma, unsigned long haddr, pmd_t *pmd,
> struct page *zero_page)
> {
> pmd_t entry;
> - if (!pmd_none(*pmd))
> - return false;
> +
Wat? So you just bindly overwrite whatever is there?
NAK.
> entry = mk_pmd(zero_page, vma->vm_page_prot);
> entry = pmd_mkhuge(entry);
> if (pgtable)
> pgtable_trans_huge_deposit(mm, pmd, pgtable);
> set_pmd_at(mm, haddr, pmd, entry);
> mm_inc_nr_ptes(mm);
> - return true;
> }
>
> vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf)
> --
> 2.20.1
>
>
--
Kirill A. Shutemov