Re: [PATCH v5 05/11] thp: change_huge_pmd(): keep huge zero page write-protected

David Rientjes
2012-11-14T23:12:57Z

On Wed, 7 Nov 2012, Kirill A. Shutemov wrote:

> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index d767a7c..05490b3 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -1259,6 +1259,8 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
> pmd_t entry;
> entry = pmdp_get_and_clear(mm, addr, pmd);
> entry = pmd_modify(entry, newprot);
> + if (is_huge_zero_pmd(entry))
> + entry = pmd_wrprotect(entry);
> set_pmd_at(mm, addr, pmd, entry);
> spin_unlock(&vma->vm_mm->page_table_lock);
> ret = 1;

Nack, this should be handled in pmd_modify().