Re: [PATCH v3 3/4] mm/damon/ops-common: Refactor to use {pte|pmd}p_clear_young_notify()

[SeongJae Park]

Hi Ryan,

On Fri, 2 Jun 2023 10:29:48 +0100 Ryan Roberts <ryan.roberts@xxxxxxx> wrote:

> With the fix in place to atomically test and clear young on ptes and
> pmds, simplify the code to handle the clearing for both the primary mmu
> and the mmu notifier with a single API call.
> 
> Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx>

Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>


Thanks,
SJ

> ---
>  mm/damon/ops-common.c | 22 ++--------------------
>  1 file changed, 2 insertions(+), 20 deletions(-)
> 
> diff --git a/mm/damon/ops-common.c b/mm/damon/ops-common.c
> index acc264b97903..d4ab81229136 100644
> --- a/mm/damon/ops-common.c
> +++ b/mm/damon/ops-common.c
> @@ -39,21 +39,12 @@ struct folio *damon_get_folio(unsigned long pfn)
>  
>  void damon_ptep_mkold(pte_t *pte, struct vm_area_struct *vma, unsigned long addr)
>  {
> -	bool referenced = false;
>  	struct folio *folio = damon_get_folio(pte_pfn(*pte));
>  
>  	if (!folio)
>  		return;
>  
> -	if (ptep_test_and_clear_young(vma, addr, pte))
> -		referenced = true;
> -
> -#ifdef CONFIG_MMU_NOTIFIER
> -	if (mmu_notifier_clear_young(vma->vm_mm, addr, addr + PAGE_SIZE))
> -		referenced = true;
> -#endif /* CONFIG_MMU_NOTIFIER */
> -
> -	if (referenced)
> +	if (ptep_clear_young_notify(vma, addr, pte))
>  		folio_set_young(folio);
>  
>  	folio_set_idle(folio);
> @@ -63,21 +54,12 @@ void damon_ptep_mkold(pte_t *pte, struct vm_area_struct *vma, unsigned long addr
>  void damon_pmdp_mkold(pmd_t *pmd, struct vm_area_struct *vma, unsigned long addr)
>  {
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> -	bool referenced = false;
>  	struct folio *folio = damon_get_folio(pmd_pfn(*pmd));
>  
>  	if (!folio)
>  		return;
>  
> -	if (pmdp_test_and_clear_young(vma, addr, pmd))
> -		referenced = true;
> -
> -#ifdef CONFIG_MMU_NOTIFIER
> -	if (mmu_notifier_clear_young(vma->vm_mm, addr, addr + HPAGE_PMD_SIZE))
> -		referenced = true;
> -#endif /* CONFIG_MMU_NOTIFIER */
> -
> -	if (referenced)
> +	if (pmdp_clear_young_notify(vma, addr, pmd))
>  		folio_set_young(folio);
>  
>  	folio_set_idle(folio);
> -- 
> 2.25.1
> 
>