Re: [RFC PATCH 2/5] mm: page_owner: add support for splitting to any order in split page_owner.

From: Zi Yan
Date: Mon Mar 21 2022 - 15:08:29 EST


On 21 Mar 2022, at 15:02, Roman Gushchin wrote:

> On Mon, Mar 21, 2022 at 10:21:25AM -0400, Zi Yan wrote:
>> From: Zi Yan <ziy@xxxxxxxxxx>
>>
>> It adds a new_order parameter to set new page order in page owner and
>> uses old_order instead of nr to make the parameters look consistent.
>> It prepares for upcoming changes to support split huge page to any
>> lower order.
>>
>> Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
>> ---
>> include/linux/page_owner.h | 12 +++++++-----
>> mm/huge_memory.c | 3 ++-
>> mm/page_alloc.c | 2 +-
>> mm/page_owner.c | 13 +++++++------
>> 4 files changed, 17 insertions(+), 13 deletions(-)
>>
>> diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h
>> index 119a0c9d2a8b..16050cc89274 100644
>> --- a/include/linux/page_owner.h
>> +++ b/include/linux/page_owner.h
>> @@ -11,7 +11,8 @@ extern struct page_ext_operations page_owner_ops;
>> extern void __reset_page_owner(struct page *page, unsigned short order);
>> extern void __set_page_owner(struct page *page,
>> unsigned short order, gfp_t gfp_mask);
>> -extern void __split_page_owner(struct page *page, unsigned int nr);
>> +extern void __split_page_owner(struct page *page, unsigned short old_order,
>> + unsigned short new_order);
>
> Unsigned short here,
>
>> extern void __folio_copy_owner(struct folio *newfolio, struct folio *old);
>> extern void __set_page_owner_migrate_reason(struct page *page, int reason);
>> extern void __dump_page_owner(const struct page *page);
>> @@ -31,10 +32,11 @@ static inline void set_page_owner(struct page *page,
>> __set_page_owner(page, order, gfp_mask);
>> }
>>
>> -static inline void split_page_owner(struct page *page, unsigned int nr)
>> +static inline void split_page_owner(struct page *page, unsigned int old_order,
>> + unsigned int new_order)
>
> but unsigned int here.
>
>> {
>> if (static_branch_unlikely(&page_owner_inited))
>> - __split_page_owner(page, nr);
>> + __split_page_owner(page, old_order, new_order);
>> }
>> static inline void folio_copy_owner(struct folio *newfolio, struct folio *old)
>> {
>> @@ -56,11 +58,11 @@ static inline void reset_page_owner(struct page *page, unsigned short order)
>> {
>> }
>> static inline void set_page_owner(struct page *page,
>> - unsigned int order, gfp_t gfp_mask)
>> + unsigned short order, gfp_t gfp_mask)
>> {
>> }
>> static inline void split_page_owner(struct page *page,
>> - unsigned short order)
>> + unsigned short old_order, unsigned short new_order)
>> {
>> }
>> static inline void folio_copy_owner(struct folio *newfolio, struct folio *folio)
>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>> index 640040c386f0..fcfa46af6c4c 100644
>> --- a/mm/huge_memory.c
>> +++ b/mm/huge_memory.c
>> @@ -2367,6 +2367,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
>> struct lruvec *lruvec;
>> struct address_space *swap_cache = NULL;
>> unsigned long offset = 0;
>> + unsigned int order = thp_order(head);
>> unsigned int nr = thp_nr_pages(head);
>> int i;
>>
>> @@ -2408,7 +2409,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
>> unlock_page_lruvec(lruvec);
>> /* Caller disabled irqs, so they are still disabled here */
>>
>> - split_page_owner(head, nr);
>> + split_page_owner(head, order, 0);
>>
>> /* See comment in __split_huge_page_tail() */
>> if (PageAnon(head)) {
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index d982919b9e51..9cac40c26c58 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -3514,7 +3514,7 @@ void split_page(struct page *page, unsigned int order)
>>
>> for (i = 1; i < (1 << order); i++)
>> set_page_refcounted(page + i);
>> - split_page_owner(page, 1 << order);
>> + split_page_owner(page, order, 0);
>> split_page_memcg(page, 1 << order, 0);
>> }
>> EXPORT_SYMBOL_GPL(split_page);
>> diff --git a/mm/page_owner.c b/mm/page_owner.c
>> index 0a9588506571..52013c846d19 100644
>> --- a/mm/page_owner.c
>> +++ b/mm/page_owner.c
>> @@ -202,19 +202,20 @@ void __set_page_owner_migrate_reason(struct page *page, int reason)
>> page_owner->last_migrate_reason = reason;
>> }
>>
>> -void __split_page_owner(struct page *page, unsigned int nr)
>> +void __split_page_owner(struct page *page, unsigned short old_order,
>> + unsigned short new_order)
>
> And short again here. Please, make it consistent.
>
> Other than that, looks good to me. Please, feel free to add
> Reviewed-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
> after fixing the type inconsistency.

Sure. Will fix all the inconsistent types. Thanks.


--
Best Regards,
Yan, Zi

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