ascend: mm: add an owner for mm_struct

ascend inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4EUVI
CVE: NA

-------------------------------------------------

The mm->owner is only used for MEMCG currently, but the ascend share
pool features will use it later, so make it to a general features and
select it for CONFIG_MEMCG.
Signed-off-by: NTang Yizhou <tangyizhou@huawei.com>
Signed-off-by: NDing Tianhong <dingtianhong@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

include/linux/mm_types.h

@@ -455,7 +455,7 @@ struct mm_struct {
 		spinlock_t			ioctx_lock;
 		struct kioctx_table __rcu	*ioctx_table;
 #endif
-#ifdef CONFIG_MEMCG
+#ifdef CONFIG_MM_OWNER
 		/*
 		 * "owner" points to a task that is regarded as the canonical
 		 * user/owner of this mm. All of the following must be true in

init/Kconfig

@@ -704,6 +704,7 @@ config MEMCG
 	bool "Memory controller"
 	select PAGE_COUNTER
 	select EVENTFD
+	select MM_OWNER
 	help
 	  Provides control over the memory footprint of tasks in a cgroup.
 

kernel/exit.c

@@ -330,7 +330,7 @@ kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
 	}
 }
 
-#ifdef CONFIG_MEMCG
+#ifdef CONFIG_MM_OWNER
 /*
  * A task is exiting.   If it owned this mm, find a new owner for the mm.
  */
@@ -416,7 +416,7 @@ void mm_update_next_owner(struct mm_struct *mm)
 	task_unlock(c);
 	put_task_struct(c);
 }
-#endif /* CONFIG_MEMCG */
+#endif /* CONFIG_MM_OWNER */
 
 /*
  * Turn us into a lazy TLB process if we

kernel/fork.c

@@ -962,7 +962,7 @@ static void mm_init_aio(struct mm_struct *mm)
 static __always_inline void mm_clear_owner(struct mm_struct *mm,
 					   struct task_struct *p)
 {
-#ifdef CONFIG_MEMCG
+#ifdef CONFIG_MM_OWNER
 	if (mm->owner == p)
 		WRITE_ONCE(mm->owner, NULL);
 #endif
@@ -970,7 +970,7 @@ static __always_inline void mm_clear_owner(struct mm_struct *mm,
 
 static void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
 {
-#ifdef CONFIG_MEMCG
+#ifdef CONFIG_MM_OWNER
 	mm->owner = p;
 #endif
 }

mm/Kconfig

@@ -299,6 +299,10 @@ config VIRT_TO_BUS
 	  deprecated interface virt_to_bus().  All new architectures
 	  should probably not select this.
 
+config MM_OWNER
+	bool "Enable the ownership the mm owner"
+	help
+	  This option enables mm_struct's to have an owner.
 
 config MMU_NOTIFIER
 	bool

mm/debug.c

@@ -129,7 +129,7 @@ void dump_mm(const struct mm_struct *mm)
 #ifdef CONFIG_AIO
 		"ioctx_table %px\n"
 #endif
-#ifdef CONFIG_MEMCG
+#ifdef CONFIG_MM_OWNER
 		"owner %px "
 #endif
 		"exe_file %px\n"