cgroup: get rid of populate for memcg
The last man standing justifying the need for populate() is the
sock memcg initialization functions. Now that we are able to pass
a struct mem_cgroup instead of a struct cgroup to the socket
initialization, there is nothing that stops us from initializing
everything in create().
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
CC: Li Zefan <lizefan@huawei.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Michal Hocko <mhocko@suse.cz>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 785c323..901bb03 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4640,7 +4640,7 @@
#endif /* CONFIG_NUMA */
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
-static int register_kmem_files(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
+static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
return mem_cgroup_sockets_init(memcg, ss);
};
@@ -4650,7 +4650,7 @@
mem_cgroup_sockets_destroy(memcg);
}
#else
-static int register_kmem_files(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
+static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
return 0;
}
@@ -5010,6 +5010,17 @@
memcg->move_charge_at_immigrate = 0;
mutex_init(&memcg->thresholds_lock);
spin_lock_init(&memcg->move_lock);
+
+ error = memcg_init_kmem(memcg, &mem_cgroup_subsys);
+ if (error) {
+ /*
+ * We call put now because our (and parent's) refcnts
+ * are already in place. mem_cgroup_put() will internally
+ * call __mem_cgroup_free, so return directly
+ */
+ mem_cgroup_put(memcg);
+ return ERR_PTR(error);
+ }
return &memcg->css;
free_out:
__mem_cgroup_free(memcg);
@@ -5032,13 +5043,6 @@
mem_cgroup_put(memcg);
}
-static int mem_cgroup_populate(struct cgroup_subsys *ss,
- struct cgroup *cont)
-{
- struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
- return register_kmem_files(memcg, ss);
-}
-
#ifdef CONFIG_MMU
/* Handlers for move charge at task migration. */
#define PRECHARGE_COUNT_AT_ONCE 256
@@ -5622,7 +5626,6 @@
.create = mem_cgroup_create,
.pre_destroy = mem_cgroup_pre_destroy,
.destroy = mem_cgroup_destroy,
- .populate = mem_cgroup_populate,
.can_attach = mem_cgroup_can_attach,
.cancel_attach = mem_cgroup_cancel_attach,
.attach = mem_cgroup_move_task,