Re: [PATCH 05/16] mm/huge_memory: use helper touch_pmd in huge_pmd_set_accessed

From: Muchun Song
Date: Thu Jun 23 2022 - 02:43:43 EST


On Thu, Jun 23, 2022 at 01:06:16AM +0800, Miaohe Lin wrote:
> Use helper touch_pmd to set pmd accessed to simplify the code and improve
> the readability. No functional change intended.
>
> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
> ---
> mm/huge_memory.c | 16 +++++-----------
> 1 file changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index a0c0e4bf9c1e..c6302fe6704b 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -1297,21 +1297,15 @@ void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
>
> void huge_pmd_set_accessed(struct vm_fault *vmf)
> {
> - pmd_t entry;
> - unsigned long haddr;
> - bool write = vmf->flags & FAULT_FLAG_WRITE;
> - pmd_t orig_pmd = vmf->orig_pmd;
> + int flags = 0;
>
> vmf->ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd);
> - if (unlikely(!pmd_same(*vmf->pmd, orig_pmd)))
> + if (unlikely(!pmd_same(*vmf->pmd, vmf->orig_pmd)))
> goto unlock;
>
> - entry = pmd_mkyoung(orig_pmd);
> - if (write)
> - entry = pmd_mkdirty(entry);
> - haddr = vmf->address & HPAGE_PMD_MASK;
> - if (pmdp_set_access_flags(vmf->vma, haddr, vmf->pmd, entry, write))
> - update_mmu_cache_pmd(vmf->vma, vmf->address, vmf->pmd);
> + if (vmf->flags & FAULT_FLAG_WRITE)
> + flags = FOLL_WRITE;

Same suggestion as mentioned in previous thread.

Thanks.

> + touch_pmd(vmf->vma, vmf->address, vmf->pmd, flags);
>
> unlock:
> spin_unlock(vmf->ptl);
> --
> 2.23.0
>
>