memcg: add mem_cgroup_uncharge_folios()

Almost identical to mem_cgroup_uncharge_list(), except it takes a
folio_batch instead of a list_head.

Link: https://lkml.kernel.org/r/20240227174254.710559-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 9a2dea92be0e85967d580a7089600ed7b2186c38..35a0d7a851f039b1202401f3854981b144c837e0 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -721,10 +721,16 @@ static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
        __mem_cgroup_uncharge_list(page_list);
 }
 
-void mem_cgroup_cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages);
+void __mem_cgroup_uncharge_folios(struct folio_batch *folios);
+static inline void mem_cgroup_uncharge_folios(struct folio_batch *folios)
+{
+       if (mem_cgroup_disabled())
+               return;
+       __mem_cgroup_uncharge_folios(folios);
+}
 
+void mem_cgroup_cancel_charge(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);
 
 /**
@@ -1299,6 +1305,10 @@ static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
 {
 }
 
+static inline void mem_cgroup_uncharge_folios(struct folio_batch *folios)
+{
+}
+
 static inline void mem_cgroup_cancel_charge(struct mem_cgroup *memcg,
                unsigned int nr_pages)
 {

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e4864e2729e6be13e8c67db1796028f1f256443f..2edb250d131b61c683a59685dedada51924fcce9 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -33,6 +33,7 @@
 #include <linux/shmem_fs.h>
 #include <linux/hugetlb.h>
 #include <linux/pagemap.h>
+#include <linux/pagevec.h>
 #include <linux/vm_event_item.h>
 #include <linux/smp.h>
 #include <linux/page-flags.h>
@@ -7531,6 +7532,18 @@ void __mem_cgroup_uncharge_list(struct list_head *page_list)
                uncharge_batch(&ug);
 }
 
+void __mem_cgroup_uncharge_folios(struct folio_batch *folios)
+{
+       struct uncharge_gather ug;
+       unsigned int i;
+
+       uncharge_gather_clear(&ug);
+       for (i = 0; i < folios->nr; i++)
+               uncharge_folio(folios->folios[i], &ug);
+       if (ug.memcg)
+               uncharge_batch(&ug);
+}
+
 /**
  * mem_cgroup_replace_folio - Charge a folio's replacement.
  * @old: Currently circulating folio.