[PATCH v2 15/46] mm/memcg: Add folio_uncharge_cgroup()

From: Matthew Wilcox (Oracle)
Date: Tue Jun 22 2021 - 08:28:49 EST


Reimplement mem_cgroup_uncharge() as a wrapper around
folio_uncharge_cgroup().

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 5 +++++
mm/folio-compat.c | 5 +++++
mm/memcontrol.c | 14 +++++++-------
3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index a50e5cee6d2c..d4b2bc939eee 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -705,6 +705,7 @@ static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg)
}

int folio_charge_cgroup(struct folio *, struct mm_struct *, gfp_t);
+void folio_uncharge_cgroup(struct folio *);

int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask);
int mem_cgroup_swapin_charge_page(struct page *page, struct mm_struct *mm,
@@ -1224,6 +1225,10 @@ static inline int folio_charge_cgroup(struct folio *folio,
return 0;
}

+static inline void folio_uncharge_cgroup(struct folio *folio)
+{
+}
+
static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask)
{
diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 1d71b8b587f8..d229b979b00d 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -54,4 +54,9 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp)
{
return folio_charge_cgroup(page_folio(page), mm, gfp);
}
+
+void mem_cgroup_uncharge(struct page *page)
+{
+ folio_uncharge_cgroup(page_folio(page));
+}
#endif
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 69638f84d11b..a6befc0843e7 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6717,24 +6717,24 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
}

/**
- * mem_cgroup_uncharge - uncharge a page
- * @page: page to uncharge
+ * folio_uncharge_cgroup - Uncharge a folio.
+ * @folio: Folio to uncharge.
*
- * Uncharge a page previously charged with mem_cgroup_charge().
+ * Uncharge a folio previously charged with folio_charge_cgroup().
*/
-void mem_cgroup_uncharge(struct page *page)
+void folio_uncharge_cgroup(struct folio *folio)
{
struct uncharge_gather ug;

if (mem_cgroup_disabled())
return;

- /* Don't touch page->lru of any random page, pre-check: */
- if (!page_memcg(page))
+ /* Don't touch folio->lru of any random page, pre-check: */
+ if (!folio_memcg(folio))
return;

uncharge_gather_clear(&ug);
- uncharge_page(page, &ug);
+ uncharge_page(&folio->page, &ug);
uncharge_batch(&ug);
}

--
2.30.2