[PATCH 1/2] mm, memcontrol: Add memcg_iterate_all()

Waiman Long
2019-06-24T17:42:18Z

Add a memcg_iterate_all() function for iterating all the available
memory cgroups and call the given callback function for each of the
memory cgruops.

Signed-off-by: Waiman Long <longman@redhat.com>
---
include/linux/memcontrol.h | 3 +++
mm/memcontrol.c | 13 +++++++++++++
2 files changed, 16 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 1dcb763bb610..0e31418e5a47 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1268,6 +1268,9 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep);
void memcg_kmem_put_cache(struct kmem_cache *cachep);

+extern void memcg_iterate_all(void (*callback)(struct mem_cgroup *memcg,
+ void *arg), void *arg);
+
#ifdef CONFIG_MEMCG_KMEM
int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
void __memcg_kmem_uncharge(struct page *page, int order);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ba9138a4a1de..c1c4706f7696 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -443,6 +443,19 @@ static int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg)
static void memcg_free_shrinker_maps(struct mem_cgroup *memcg) { }
#endif /* CONFIG_MEMCG_KMEM */

+/*
+ * Iterate all the memory cgroups and call the given callback function
+ * for each of the memory cgroups.
+ */
+void memcg_iterate_all(void (*callback)(struct mem_cgroup *memcg, void *arg),
+ void *arg)
+{
+ struct mem_cgroup *memcg;
+
+ for_each_mem_cgroup(memcg)
+ callback(memcg, arg);
+}
+
/**
* mem_cgroup_css_from_page - css of the memcg associated with a page
* @page: page of interest
--
2.18.1