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author | Dave Airlie <airlied@redhat.com> | 2018-03-28 14:30:41 +1000 |
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committer | Dave Airlie <airlied@redhat.com> | 2018-03-28 14:30:41 +1000 |
commit | 2b4f44eec2be2688511c2b617d0e1b4f94c45ba4 (patch) | |
tree | 533c03602f4ae6d6404db6fa56c88e6f83e1bebe /include/linux/sched/mm.h | |
parent | 33d009cd889490838c5db9b9339856c9e3d3facc (diff) | |
parent | 3eb2ce825ea1ad89d20f7a3b5780df850e4be274 (diff) |
Backmerge tag 'v4.16-rc7' into drm-next
Linux 4.16-rc7
This was requested by Daniel, and things were getting
a bit hard to reconcile, most of the conflicts were
trivial though.
Diffstat (limited to 'include/linux/sched/mm.h')
-rw-r--r-- | include/linux/sched/mm.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index 1149533aa2fa..9806184bb3d5 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -36,7 +36,18 @@ static inline void mmgrab(struct mm_struct *mm) atomic_inc(&mm->mm_count); } -extern void mmdrop(struct mm_struct *mm); +extern void __mmdrop(struct mm_struct *mm); + +static inline void mmdrop(struct mm_struct *mm) +{ + /* + * The implicit full barrier implied by atomic_dec_and_test() is + * required by the membarrier system call before returning to + * user-space, after storing to rq->curr. + */ + if (unlikely(atomic_dec_and_test(&mm->mm_count))) + __mmdrop(mm); +} /** * mmget() - Pin the address space associated with a &struct mm_struct. |