Shrinker debugfs requires a way to represent memory cgroups without
using full paths, both for displaying information and getting input
from a user.
Cgroup inode number is a perfect way, already used by bpf.
This commit adds a couple of helper functions which will be used
to handle memcg-aware shrinkers.
Signed-off-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
---
include/linux/memcontrol.h | 21 +++++++++++++++++++++
mm/memcontrol.c | 23 +++++++++++++++++++++++
2 files changed, 44 insertions(+)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index fe580cb96683..a6de9e5c1549 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -831,6 +831,15 @@ static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
}
struct mem_cgroup *mem_cgroup_from_id(unsigned short id);
+#ifdef CONFIG_SHRINKER_DEBUG
+static inline unsigned long mem_cgroup_ino(struct mem_cgroup *memcg)
+{
+ return memcg ? cgroup_ino(memcg->css.cgroup) : 0;
+}
+
+struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino);
+#endif
+
static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
{
return mem_cgroup_from_css(seq_css(m));
@@ -1324,6 +1333,18 @@ static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
return NULL;
}
+#ifdef CONFIG_SHRINKER_DEBUG
+static inline unsigned long mem_cgroup_ino(struct mem_cgroup *memcg)
+{
+ return 0;
+}
+
+static inline struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino)
+{
+ return NULL;
+}
+#endif
+
static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
{
return NULL;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 04cea4fa362a..e6472728fa66 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5018,6 +5018,29 @@ struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
return idr_find(&mem_cgroup_idr, id);
}
+#ifdef CONFIG_SHRINKER_DEBUG
+struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino)
+{
+ struct cgroup *cgrp;
+ struct cgroup_subsys_state *css;
+ struct mem_cgroup *memcg;
+
+ cgrp = cgroup_get_from_id(ino);
+ if (!cgrp)
+ return ERR_PTR(-ENOENT);
+
+ css = cgroup_get_e_css(cgrp, &memory_cgrp_subsys);
+ if (css)
+ memcg = container_of(css, struct mem_cgroup, css);
+ else
+ memcg = ERR_PTR(-ENOENT);
+
+ cgroup_put(cgrp);
+
+ return memcg;
+}
+#endif
+
static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
{
struct mem_cgroup_per_node *pn;
--
2.35.3
