diff options
Diffstat (limited to 'include/linux/sched.h')
| -rw-r--r-- | include/linux/sched.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 451e241f32c5..7cfa5546c840 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2904,6 +2904,28 @@ static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig) */ extern struct mm_struct * mm_alloc(void); +/** + * mmgrab() - Pin a &struct mm_struct. + * @mm: The &struct mm_struct to pin. + * + * Make sure that @mm will not get freed even after the owning task + * exits. This doesn't guarantee that the associated address space + * will still exist later on and mmget_not_zero() has to be used before + * accessing it. + * + * This is a preferred way to to pin @mm for a longer/unbounded amount + * of time. + * + * Use mmdrop() to release the reference acquired by mmgrab(). + * + * See also <Documentation/vm/active_mm.txt> for an in-depth explanation + * of &mm_struct.mm_count vs &mm_struct.mm_users. + */ +static inline void mmgrab(struct mm_struct *mm) +{ + atomic_inc(&mm->mm_count); +} + /* mmdrop drops the mm and the page tables */ extern void __mmdrop(struct mm_struct *); static inline void mmdrop(struct mm_struct *mm) |