cgroup: remove cgroup_subsys argument from callbacks

The argument is not used at all, and it's not necessary, because
a specific callback handler of course knows which subsys it
belongs to.

Now only ->pupulate() takes this argument, because the handlers of
this callback always call cgroup_add_file()/cgroup_add_files().

So we reduce a few lines of code, though the shrinking of object size
is minimal.

 16 files changed, 113 insertions(+), 162 deletions(-)

   text    data     bss     dec     hex filename
5486240  656987 7039960 13183187         c928d3 vmlinux.o.orig
5486170  656987 7039960 13183117         c9288d vmlinux.o

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 19 insertions, 29 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3dbff4dcde35..ae2f0a8ab761 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4580,10 +4580,9 @@ static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
         return mem_cgroup_sockets_init(cont, ss);
 };
 
-static void kmem_cgroup_destroy(struct cgroup_subsys *ss,
-                                struct cgroup *cont)
+static void kmem_cgroup_destroy(struct cgroup *cont)
 {
-        mem_cgroup_sockets_destroy(cont, ss);
+        mem_cgroup_sockets_destroy(cont);
 }
 #else
 static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
@@ -4591,8 +4590,7 @@ static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
         return 0;
 }
 
-static void kmem_cgroup_destroy(struct cgroup_subsys *ss,
-                                struct cgroup *cont)
+static void kmem_cgroup_destroy(struct cgroup *cont)
 {
 }
 #endif
@@ -4884,7 +4882,7 @@ err_cleanup:
 }
 
 static struct cgroup_subsys_state * __ref
-mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
+mem_cgroup_create(struct cgroup *cont)
 {
         struct mem_cgroup *memcg, *parent;
         long error = -ENOMEM;
@@ -4946,20 +4944,18 @@ free_out:
         return ERR_PTR(error);
 }
 
-static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss,
-                                        struct cgroup *cont)
+static int mem_cgroup_pre_destroy(struct cgroup *cont)
 {
         struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 
         return mem_cgroup_force_empty(memcg, false);
 }
 
-static void mem_cgroup_destroy(struct cgroup_subsys *ss,
-                                struct cgroup *cont)
+static void mem_cgroup_destroy(struct cgroup *cont)
 {
         struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 
-        kmem_cgroup_destroy(ss, cont);
+        kmem_cgroup_destroy(cont);
 
         mem_cgroup_put(memcg);
 }
@@ -5296,9 +5292,8 @@ static void mem_cgroup_clear_mc(void)
         mem_cgroup_end_move(from);
 }
 
-static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
-                                struct cgroup *cgroup,
-                                struct cgroup_taskset *tset)
+static int mem_cgroup_can_attach(struct cgroup *cgroup,
+                                 struct cgroup_taskset *tset)
 {
         struct task_struct *p = cgroup_taskset_first(tset);
         int ret = 0;
@@ -5336,9 +5331,8 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
         return ret;
 }
 
-static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
-                                struct cgroup *cgroup,
-                                struct cgroup_taskset *tset)
+static void mem_cgroup_cancel_attach(struct cgroup *cgroup,
+                                     struct cgroup_taskset *tset)
 {
         mem_cgroup_clear_mc();
 }
@@ -5453,9 +5447,8 @@ retry:
         up_read(&mm->mmap_sem);
 }
 
-static void mem_cgroup_move_task(struct cgroup_subsys *ss,
-                                struct cgroup *cont,
-                                struct cgroup_taskset *tset)
+static void mem_cgroup_move_task(struct cgroup *cont,
+                                 struct cgroup_taskset *tset)
 {
         struct task_struct *p = cgroup_taskset_first(tset);
         struct mm_struct *mm = get_task_mm(p);
@@ -5470,20 +5463,17 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss,
                 mem_cgroup_clear_mc();
 }
 #else   /* !CONFIG_MMU */
-static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
-                                struct cgroup *cgroup,
-                                struct cgroup_taskset *tset)
+static int mem_cgroup_can_attach(struct cgroup *cgroup,
+                                 struct cgroup_taskset *tset)
 {
         return 0;
 }
-static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
-                                struct cgroup *cgroup,
-                                struct cgroup_taskset *tset)
+static void mem_cgroup_cancel_attach(struct cgroup *cgroup,
+                                     struct cgroup_taskset *tset)
 {
 }
-static void mem_cgroup_move_task(struct cgroup_subsys *ss,
-                                struct cgroup *cont,
-                                struct cgroup_taskset *tset)
+static void mem_cgroup_move_task(struct cgroup *cont,
+                                 struct cgroup_taskset *tset)
 {
 }
 #endif