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| author |   Andrew Morton <akpm@linux-foundation.org> | 2018-02-21 14:45:17 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-21 15:35:42 -0800 |
| commit | d34bc48f8275b6ce0da44f639d68344891268ee9 (patch) | |
| tree | 4004ff5aceb19f3bbfb5c395e9a5df0f13a7f376 /include/linux/sched | |
| parent | tools: fix cross-compile var clobbering (diff) | |
| download | linux-dev-d34bc48f8275b6ce0da44f639d68344891268ee9.tar.xz linux-dev-d34bc48f8275b6ce0da44f639d68344891268ee9.zip | |
include/linux/sched/mm.h: re-inline mmdrop()
As Peter points out, Doing a CALL+RET for just the decrement is a bit silly.
Fixes: d70f2a14b72a4bc ("include/linux/sched/mm.h: uninline mmdrop_async(), etc")
Acked-by: Peter Zijlstra (Intel) <peterz@infraded.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/sched')
| -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. |