Re: [PATCH 3/6] mm/page_owner: Constify dump_page_owner

From: Anshuman Khandual
Date: Mon Apr 26 2021 - 23:30:33 EST



On 4/17/21 4:45 AM, Matthew Wilcox (Oracle) wrote:
> dump_page_owner() only uses struct page to find the page_ext, and
> lookup_page_ext() already takes a const argument.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> include/linux/page_owner.h | 6 +++---
> mm/page_owner.c | 2 +-
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h
> index 3468794f83d2..719bfe5108c5 100644
> --- a/include/linux/page_owner.h
> +++ b/include/linux/page_owner.h
> @@ -14,7 +14,7 @@ extern void __set_page_owner(struct page *page,
> extern void __split_page_owner(struct page *page, unsigned int nr);
> extern void __copy_page_owner(struct page *oldpage, struct page *newpage);
> extern void __set_page_owner_migrate_reason(struct page *page, int reason);
> -extern void __dump_page_owner(struct page *page);
> +extern void __dump_page_owner(const struct page *page);
> extern void pagetypeinfo_showmixedcount_print(struct seq_file *m,
> pg_data_t *pgdat, struct zone *zone);
>
> @@ -46,7 +46,7 @@ static inline void set_page_owner_migrate_reason(struct page *page, int reason)
> if (static_branch_unlikely(&page_owner_inited))
> __set_page_owner_migrate_reason(page, reason);
> }
> -static inline void dump_page_owner(struct page *page)
> +static inline void dump_page_owner(const struct page *page)
> {
> if (static_branch_unlikely(&page_owner_inited))
> __dump_page_owner(page);
> @@ -69,7 +69,7 @@ static inline void copy_page_owner(struct page *oldpage, struct page *newpage)
> static inline void set_page_owner_migrate_reason(struct page *page, int reason)
> {
> }
> -static inline void dump_page_owner(struct page *page)
> +static inline void dump_page_owner(const struct page *page)
> {
> }
> #endif /* CONFIG_PAGE_OWNER */
> diff --git a/mm/page_owner.c b/mm/page_owner.c
> index adfabb560eb9..f51a57e92aa3 100644
> --- a/mm/page_owner.c
> +++ b/mm/page_owner.c
> @@ -392,7 +392,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn,
> return -ENOMEM;
> }
>
> -void __dump_page_owner(struct page *page)
> +void __dump_page_owner(const struct page *page)
> {
> struct page_ext *page_ext = lookup_page_ext(page);
> struct page_owner *page_owner;
>

Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>