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.

Change-Id: I07980d9557cef16a102ed293bc4a8ad1f9302777
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 e4aaca1c3..d55932761 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -394,7 +394,7 @@ struct mm_struct {
 	spinlock_t		ioctx_lock;
 	struct hlist_head	ioctx_list;
 #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 aa76cc2ae..e45c95c02 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2894,7 +2894,7 @@ static inline void inc_syscfs(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
@@ -2905,7 +2905,7 @@ 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 e212cc8ff..21dec5d1e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -888,7 +888,6 @@ config RESOURCE_COUNTERS
 config MEMCG
 	bool "Memory Resource Controller for Control Groups"
 	depends on RESOURCE_COUNTERS
-	select MM_OWNER
 	help
 	  Provides a memory resource controller that manages both anonymous
 	  memory and page cache. (See Documentation/cgroups/memory.txt)
@@ -905,9 +904,6 @@ 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
@@ -1152,9 +1148,6 @@ 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 102ec4376..5dc2ae8e8 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -368,7 +368,7 @@ 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.
  */
@@ -450,7 +450,7 @@ 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 b4fabfba6..b20585cca 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1179,12 +1179,12 @@ 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.