Re: [PATCH v2 3/9] mm/hugetlb: make pud_huge() and huge_pud() aware of non-present pud entry

From: HORIGUCHI NAOYA(堀口 直也)
Date: Fri Jun 24 2022 - 04:40:49 EST


Sorry, I found that $SUBJECT mentions wrong function name (I meant
follow_huge_pud(), not huge_pud()), this will be fixed in the later version.

On Fri, Jun 24, 2022 at 08:51:47AM +0900, Naoya Horiguchi wrote:
> From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
>
> follow_pud_mask() does not support non-present pud entry now. As long as
> I tested on x86_64 server, follow_pud_mask() still simply returns
> no_page_table() for non-present_pud_entry() due to pud_bad(), so no severe
> user-visible effect should happen. But generally we should call
> follow_huge_pud() for non-present pud entry for 1GB hugetlb page.
>
> Update pud_huge() and huge_pud() to handle non-present pud entries. The

here the same typo, too.

- Naoya Horiguchi

> changes are similar to previous works for pud entries commit e66f17ff7177
> ("mm/hugetlb: take page table lock in follow_huge_pmd()") and commit
> cbef8478bee5 ("mm/hugetlb: pmd_huge() returns true for non-present hugepage").
>
> Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
> ---