From: Qi Zheng <zhengqi.arch@bytedance.com>
Refactor the memcg_reparent_objcgs() to facilitate subsequent reparenting
LRU folios here.
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
mm/memcontrol.c | 29 ++++++++++++++++++++++++-----
1 file changed, 24 insertions(+), 5 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a1573600d4188..70583394f421f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -208,15 +208,12 @@ static struct obj_cgroup *obj_cgroup_alloc(void)
return objcg;
}
-static void memcg_reparent_objcgs(struct mem_cgroup *memcg)
+static inline struct obj_cgroup *__memcg_reparent_objcgs(struct mem_cgroup *memcg,
+ struct mem_cgroup *parent)
{
struct obj_cgroup *objcg, *iter;
- struct mem_cgroup *parent = parent_mem_cgroup(memcg);
objcg = rcu_replace_pointer(memcg->objcg, NULL, true);
-
- spin_lock_irq(&objcg_lock);
-
/* 1) Ready to reparent active objcg. */
list_add(&objcg->list, &memcg->objcg_list);
/* 2) Reparent active objcg and already reparented objcgs to parent. */
@@ -225,7 +222,29 @@ static void memcg_reparent_objcgs(struct mem_cgroup *memcg)
/* 3) Move already reparented objcgs to the parent's list */
list_splice(&memcg->objcg_list, &parent->objcg_list);
+ return objcg;
+}
+
+static inline void reparent_locks(struct mem_cgroup *memcg, struct mem_cgroup *parent)
+{
+ spin_lock_irq(&objcg_lock);
+}
+
+static inline void reparent_unlocks(struct mem_cgroup *memcg, struct mem_cgroup *parent)
+{
spin_unlock_irq(&objcg_lock);
+}
+
+static void memcg_reparent_objcgs(struct mem_cgroup *memcg)
+{
+ struct obj_cgroup *objcg;
+ struct mem_cgroup *parent = parent_mem_cgroup(memcg);
+
+ reparent_locks(memcg, parent);
+
+ objcg = __memcg_reparent_objcgs(memcg, parent);
+
+ reparent_unlocks(memcg, parent);
percpu_ref_kill(&objcg->refcnt);
}
--
2.20.1