memcg: kill CONFIG_MM_OWNER

CONFIG_MM_OWNER makes no sense.  It is not user-selectable, it is only
selected by CONFIG_MEMCG automatically.  So we can kill this option in
init/Kconfig and do s/CONFIG_MM_OWNER/CONFIG_MEMCG/ globally.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 7 insertions, 14 deletions

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 8967e20cbe57..de1627232af0 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -406,7 +406,7 @@ struct mm_struct {
         spinlock_t                      ioctx_lock;
         struct kioctx_table __rcu       *ioctx_table;
 #endif
-#ifdef CONFIG_MM_OWNER
+#ifdef CONFIG_MEMCG
         /*
          * "owner" points to a task that is regarded as the canonical
          * user/owner of this mm. All of the following must be true in
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 70f67e4e6156..2f2dd7d932a2 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2967,7 +2967,7 @@ static inline void inc_syscw(struct task_struct *tsk)
 #define TASK_SIZE_OF(tsk)       TASK_SIZE
 #endif
 
-#ifdef CONFIG_MM_OWNER
+#ifdef CONFIG_MEMCG
 extern void mm_update_next_owner(struct mm_struct *mm);
 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
 #else
@@ -2978,7 +2978,7 @@ static inline void mm_update_next_owner(struct mm_struct *mm)
 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
 {
 }
-#endif /* CONFIG_MM_OWNER */
+#endif /* CONFIG_MEMCG */
 
 static inline unsigned long task_rlimit(const struct task_struct *tsk,
                 unsigned int limit)
diff --git a/init/Kconfig b/init/Kconfig
index 4a1822a1a680..0a2f09a80e90 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -933,7 +933,6 @@ config RESOURCE_COUNTERS
 config MEMCG
         bool "Memory Resource Controller for Control Groups"
         depends on RESOURCE_COUNTERS
-        select MM_OWNER
         select EVENTFD
         help
           Provides a memory resource controller that manages both anonymous
@@ -951,9 +950,6 @@ config MEMCG
           disable memory resource controller and you can avoid overheads.
           (and lose benefits of memory resource controller)
 
-          This config option also selects MM_OWNER config option, which
-          could in turn add some fork/exit overhead.
-
 config MEMCG_SWAP
         bool "Memory Resource Controller Swap Extension"
         depends on MEMCG && SWAP
@@ -1179,9 +1175,6 @@ config SCHED_AUTOGROUP
           desktop applications.  Task group autogeneration is currently based
           upon task session.
 
-config MM_OWNER
-        bool
-
 config SYSFS_DEPRECATED
         bool "Enable deprecated sysfs features to support old userspace tools"
         depends on SYSFS
diff --git a/kernel/exit.c b/kernel/exit.c
index 6ed6a1d552b5..da1b838de8a6 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -352,7 +352,7 @@ int disallow_signal(int sig)
 
 EXPORT_SYMBOL(disallow_signal);
 
-#ifdef CONFIG_MM_OWNER
+#ifdef CONFIG_MEMCG
 /*
  * A task is exiting.   If it owned this mm, find a new owner for the mm.
  */
@@ -434,7 +434,7 @@ assign_new_owner:
         task_unlock(c);
         put_task_struct(c);
 }
-#endif /* CONFIG_MM_OWNER */
+#endif /* CONFIG_MEMCG */
 
 /*
  * Turn us into a lazy TLB process if we
diff --git a/kernel/fork.c b/kernel/fork.c
index 59e3dcc5b8f2..0d53eb0dfb6f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1099,12 +1099,12 @@ static void rt_mutex_init_task(struct task_struct *p)
 #endif
 }
 
-#ifdef CONFIG_MM_OWNER
+#ifdef CONFIG_MEMCG
 void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
 {
         mm->owner = p;
 }
-#endif /* CONFIG_MM_OWNER */
+#endif /* CONFIG_MEMCG */
 
 /*
  * Initialize POSIX timer handling for a single task.