diff options
| 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 | |
| parent | 7ed1c1901fe52e6c5828deb155920b44b0adabb1 (diff) | |
| download | linux-d34bc48f8275b6ce0da44f639d68344891268ee9.tar.gz | |
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>
| -rw-r--r-- | include/linux/sched/mm.h | 13 | ||||
| -rw-r--r-- | kernel/fork.c | 15 |
2 files changed, 14 insertions, 14 deletions
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index 1149533aa2fa2..9806184bb3d54 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. diff --git a/kernel/fork.c b/kernel/fork.c index be8aa5b986662..e5d9d405ae4e5 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -592,7 +592,7 @@ static void check_mm(struct mm_struct *mm) * is dropped: either by a lazy thread or by * mmput. Free the page directory and the mm. */ -static void __mmdrop(struct mm_struct *mm) +void __mmdrop(struct mm_struct *mm) { BUG_ON(mm == &init_mm); mm_free_pgd(mm); @@ -603,18 +603,7 @@ static void __mmdrop(struct mm_struct *mm) put_user_ns(mm->user_ns); free_mm(mm); } - -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); -} -EXPORT_SYMBOL_GPL(mmdrop); +EXPORT_SYMBOL_GPL(__mmdrop); static void mmdrop_async_fn(struct work_struct *work) { |