diff mbox series

[v4,1/7] mm/memcg: use order instead of nr in split_page_memcg()

Message ID 20240213215520.1048625-2-zi.yan@sent.com
State New
Headers
Series Split a folio to any lower order folios |

Commit Message

Zi Yan Feb. 13, 2024, 9:55 p.m. UTC 
  From: Zi Yan <ziy@nvidia.com>

We do not have non power of two pages, using nr is error prone if nr
is not power-of-two. Use page order instead.

Signed-off-by: Zi Yan <ziy@nvidia.com>
---
 include/linux/memcontrol.h | 4 ++--
 mm/huge_memory.c           | 3 ++-
 mm/memcontrol.c            | 3 ++-
 mm/page_alloc.c            | 4 ++--
 4 files changed, 8 insertions(+), 6 deletions(-)

Comments

David Hildenbrand Feb. 14, 2024, 9:12 a.m. UTC | #1 
On 13.02.24 22:55, Zi Yan wrote:
> From: Zi Yan <ziy@nvidia.com>
> 
> We do not have non power of two pages, using nr is error prone if nr
> is not power-of-two. Use page order instead.
> 
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> ---
>   include/linux/memcontrol.h | 4 ++--
>   mm/huge_memory.c           | 3 ++-
>   mm/memcontrol.c            | 3 ++-
>   mm/page_alloc.c            | 4 ++--
>   4 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 4e4caeaea404..173bbb53c1ec 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -1163,7 +1163,7 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm,
>   	rcu_read_unlock();
>   }
>   
> -void split_page_memcg(struct page *head, unsigned int nr);
> +void split_page_memcg(struct page *head, int order);
>   
>   unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
>   						gfp_t gfp_mask,
> @@ -1621,7 +1621,7 @@ void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
>   {
>   }
>   
> -static inline void split_page_memcg(struct page *head, unsigned int nr)
> +static inline void split_page_memcg(struct page *head, int order)
>   {
>   }
>   
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 016e20bd813e..0cd5fba0923c 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2877,9 +2877,10 @@ static void __split_huge_page(struct page *page, struct list_head *list,
>   	unsigned long offset = 0;
>   	unsigned int nr = thp_nr_pages(head);
>   	int i, nr_dropped = 0;
> +	int order = folio_order(folio);

You could calculate "nr" from "order" here, removing the usage of 
thp_nr_pages().

>   
>   	/* complete memcg works before add pages to LRU */
> -	split_page_memcg(head, nr);
> +	split_page_memcg(head, order);
>   
>   	if (folio_test_anon(folio) && folio_test_swapcache(folio)) {

Acked-by: David Hildenbrand <david@redhat.com>
Zi Yan Feb. 14, 2024, 3:19 p.m. UTC | #2 
On 14 Feb 2024, at 4:12, David Hildenbrand wrote:

> On 13.02.24 22:55, Zi Yan wrote:
>> From: Zi Yan <ziy@nvidia.com>
>>
>> We do not have non power of two pages, using nr is error prone if nr
>> is not power-of-two. Use page order instead.
>>
>> Signed-off-by: Zi Yan <ziy@nvidia.com>
>> ---
>>   include/linux/memcontrol.h | 4 ++--
>>   mm/huge_memory.c           | 3 ++-
>>   mm/memcontrol.c            | 3 ++-
>>   mm/page_alloc.c            | 4 ++--
>>   4 files changed, 8 insertions(+), 6 deletions(-)
>>
>> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
>> index 4e4caeaea404..173bbb53c1ec 100644
>> --- a/include/linux/memcontrol.h
>> +++ b/include/linux/memcontrol.h
>> @@ -1163,7 +1163,7 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm,
>>   	rcu_read_unlock();
>>   }
>>  -void split_page_memcg(struct page *head, unsigned int nr);
>> +void split_page_memcg(struct page *head, int order);
>>    unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
>>   						gfp_t gfp_mask,
>> @@ -1621,7 +1621,7 @@ void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
>>   {
>>   }
>>  -static inline void split_page_memcg(struct page *head, unsigned int nr)
>> +static inline void split_page_memcg(struct page *head, int order)
>>   {
>>   }
>>  diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>> index 016e20bd813e..0cd5fba0923c 100644
>> --- a/mm/huge_memory.c
>> +++ b/mm/huge_memory.c
>> @@ -2877,9 +2877,10 @@ static void __split_huge_page(struct page *page, struct list_head *list,
>>   	unsigned long offset = 0;
>>   	unsigned int nr = thp_nr_pages(head);
>>   	int i, nr_dropped = 0;
>> +	int order = folio_order(folio);
>
> You could calculate "nr" from "order" here, removing the usage of thp_nr_pages().

Sure.

>
>>    	/* complete memcg works before add pages to LRU */
>> -	split_page_memcg(head, nr);
>> +	split_page_memcg(head, order);
>>    	if (folio_test_anon(folio) && folio_test_swapcache(folio)) {
>
> Acked-by: David Hildenbrand <david@redhat.com>

Thanks.

--
Best Regards,
Yan, Zi
diff mbox series

Patch

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 4e4caeaea404..173bbb53c1ec 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1163,7 +1163,7 @@  static inline void memcg_memory_event_mm(struct mm_struct *mm,
 	rcu_read_unlock();
 }
 
-void split_page_memcg(struct page *head, unsigned int nr);
+void split_page_memcg(struct page *head, int order);
 
 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
 						gfp_t gfp_mask,
@@ -1621,7 +1621,7 @@  void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
 {
 }
 
-static inline void split_page_memcg(struct page *head, unsigned int nr)
+static inline void split_page_memcg(struct page *head, int order)
 {
 }
 
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 016e20bd813e..0cd5fba0923c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2877,9 +2877,10 @@  static void __split_huge_page(struct page *page, struct list_head *list,
 	unsigned long offset = 0;
 	unsigned int nr = thp_nr_pages(head);
 	int i, nr_dropped = 0;
+	int order = folio_order(folio);
 
 	/* complete memcg works before add pages to LRU */
-	split_page_memcg(head, nr);
+	split_page_memcg(head, order);
 
 	if (folio_test_anon(folio) && folio_test_swapcache(folio)) {
 		offset = swp_offset(folio->swap);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 93ad8640b741..404e529644c0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3608,11 +3608,12 @@  void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size)
 /*
  * Because page_memcg(head) is not set on tails, set it now.
  */
-void split_page_memcg(struct page *head, unsigned int nr)
+void split_page_memcg(struct page *head, int order)
 {
 	struct folio *folio = page_folio(head);
 	struct mem_cgroup *memcg = folio_memcg(folio);
 	int i;
+	unsigned int nr = 1 << order;
 
 	if (mem_cgroup_disabled() || !memcg)
 		return;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7ae4b74c9e5c..7c927b84e16c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2653,7 +2653,7 @@  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_memcg(page, 1 << order);
+	split_page_memcg(page, order);
 }
 EXPORT_SYMBOL_GPL(split_page);
 
@@ -4838,7 +4838,7 @@  static void *make_alloc_exact(unsigned long addr, unsigned int order,
 		struct page *last = page + nr;
 
 		split_page_owner(page, 1 << order);
-		split_page_memcg(page, 1 << order);
+		split_page_memcg(page, order);
 		while (page < --last)
 			set_page_refcounted(last);