Re: [PATCH v2 11/11] mm/memory-failure: Pass the folio to collect_procs_ksm()

[Jane Chu <jane.chu@xxxxxxxxxx>]

On 4/8/2024 12:42 PM, Matthew Wilcox (Oracle) wrote:

> We've already calculated it, so pass it in instead of recalculating it
> in collect_procs_ksm().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
>   include/linux/ksm.h | 14 +++-----------
>   mm/ksm.c            |  5 ++---
>   mm/memory-failure.c |  2 +-
>   3 files changed, 6 insertions(+), 15 deletions(-)
>
> diff --git a/include/linux/ksm.h b/include/linux/ksm.h
> index 358803cfd4d5..52c63a9c5a9c 100644
> --- a/include/linux/ksm.h
> +++ b/include/linux/ksm.h
> @@ -81,15 +81,9 @@ struct folio *ksm_might_need_to_copy(struct folio *folio,
>   
>   void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc);
>   void folio_migrate_ksm(struct folio *newfolio, struct folio *folio);
> -
> -#ifdef CONFIG_MEMORY_FAILURE
> -void collect_procs_ksm(struct page *page, struct list_head *to_kill,
> -		       int force_early);
> -#endif
> -
> -#ifdef CONFIG_PROC_FS
> +void collect_procs_ksm(struct folio *folio, struct page *page,
> +		struct list_head *to_kill, int force_early);
>   long ksm_process_profit(struct mm_struct *);
> -#endif /* CONFIG_PROC_FS */
Why is the #ifdef-#endif CONFIG_PROC_FS removed?  In ksm.c, 
ksm_process_profit() is defined within the config switch.
>   
>   #else  /* !CONFIG_KSM */
>   
> @@ -120,12 +114,10 @@ static inline void ksm_might_unmap_zero_page(struct mm_struct *mm, pte_t pte)
>   {
>   }
>   
> -#ifdef CONFIG_MEMORY_FAILURE
> -static inline void collect_procs_ksm(struct page *page,
> +static inline void collect_procs_ksm(struct folio *folio, struct page *page,
>   				     struct list_head *to_kill, int force_early)
>   {
>   }
> -#endif
>   
>   #ifdef CONFIG_MMU
>   static inline int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
> diff --git a/mm/ksm.c b/mm/ksm.c
> index 8c001819cf10..7d032b52002f 100644
> --- a/mm/ksm.c
> +++ b/mm/ksm.c
> @@ -3172,12 +3172,11 @@ void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc)
>   /*
>    * Collect processes when the error hit an ksm page.
>    */
> -void collect_procs_ksm(struct page *page, struct list_head *to_kill,
> -		       int force_early)
> +void collect_procs_ksm(struct folio *folio, struct page *page,
> +		struct list_head *to_kill, int force_early)
>   {
>   	struct ksm_stable_node *stable_node;
>   	struct ksm_rmap_item *rmap_item;
> -	struct folio *folio = page_folio(page);
>   	struct vm_area_struct *vma;
>   	struct task_struct *tsk;
>   
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 1c3cf1fe4964..0630e34b583b 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -713,7 +713,7 @@ static void collect_procs(struct folio *folio, struct page *page,
>   	if (!folio->mapping)
>   		return;
>   	if (unlikely(folio_test_ksm(folio)))
> -		collect_procs_ksm(page, tokill, force_early);
> +		collect_procs_ksm(folio, page, tokill, force_early);
>   	else if (folio_test_anon(folio))
>   		collect_procs_anon(folio, page, tokill, force_early);
>   	else

thanks,

-jane