Expose functions to charge/uncharge memcg with a number of pages instead
of a folio.

Signed-off-by: Eric Chanudet <echanude@redhat.com>
---
 include/linux/memcontrol.h |  4 ++++
 mm/memcontrol.c            | 24 ++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 70b685a85bf4cd0e830c9c0253e4d48f75957fe4..32f03890f13e06551fc910515eb478597c1235d8 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -642,6 +642,8 @@ static inline bool mem_cgroup_below_min(struct mem_cgroup *target,
 
 int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp);
 
+int mem_cgroup_try_charge_pages(struct mem_cgroup *memcg, gfp_t gfp_mask,
+				unsigned int nr_pages);
 /**
  * mem_cgroup_charge - Charge a newly allocated folio to a cgroup.
  * @folio: Folio to charge.
@@ -692,6 +694,8 @@ static inline void mem_cgroup_uncharge_folios(struct folio_batch *folios)
 	__mem_cgroup_uncharge_folios(folios);
 }
 
+void mem_cgroup_uncharge_pages(struct mem_cgroup *memcg, unsigned int nr_pages);
+
 void mem_cgroup_replace_folio(struct folio *old, struct folio *new);
 void mem_cgroup_migrate(struct folio *old, struct folio *new);
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 772bac21d15584ce495cba6ad2eebfa7f693677f..49ed069a2dafd5d26d77e6737dffe7e64ba5118c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4764,6 +4764,24 @@ int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp)
 	return ret;
 }
 
+/**
+ * mem_cgroup_try_charge_pages - charge pages to a memory cgroup
+ * @memcg: memory cgroup to charge
+ * @gfp_mask: reclaim mode
+ * @nr_pages: number of pages to charge
+ *
+ * Try to charge @nr_pages to @memcg through try_charge_memcg.
+ *
+ * Returns 0 on success, an error code on failure.
+ */
+int mem_cgroup_try_charge_pages(struct mem_cgroup *memcg, gfp_t gfp_mask,
+				unsigned int nr_pages)
+{
+	return try_charge(memcg, gfp_mask, nr_pages);
+}
+EXPORT_SYMBOL_GPL(mem_cgroup_try_charge_pages);
+
+
 /**
  * mem_cgroup_charge_hugetlb - charge the memcg for a hugetlb folio
  * @folio: folio being charged
@@ -4948,6 +4966,12 @@ void __mem_cgroup_uncharge_folios(struct folio_batch *folios)
 		uncharge_batch(&ug);
 }
 
+void mem_cgroup_uncharge_pages(struct mem_cgroup *memcg, unsigned int nr_pages)
+{
+	memcg_uncharge(memcg, nr_pages);
+}
+EXPORT_SYMBOL_GPL(mem_cgroup_uncharge_pages);
+
 /**
  * mem_cgroup_replace_folio - Charge a folio's replacement.
  * @old: Currently circulating folio.

-- 
2.52.0

On Fri, Apr 03, 2026 at 10:08:35AM -0400, Eric Chanudet wrote:
> Expose functions to charge/uncharge memcg with a number of pages instead
> of a folio.
> 
> Signed-off-by: Eric Chanudet <echanude@redhat.com>

No naked number accounting, please. The reason existing charge paths
require you to pass an object is because there are other memory
attributes we need to track (such as NUMA node location).