From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: 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@xxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/sched/mm.h | 13 ++++++++++++-
kernel/fork.c | 15 ++-------------
2 files changed, 14 insertions(+), 14 deletions(-)
diff -puN include/linux/sched/mm.h~include-linux-sched-mmh-re-inline-mmdrop include/linux/sched/mm.h
--- a/include/linux/sched/mm.h~include-linux-sched-mmh-re-inline-mmdrop
+++ a/include/linux/sched/mm.h
@@ -36,7 +36,18 @@ static inline void mmgrab(struct mm_stru
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 -puN kernel/fork.c~include-linux-sched-mmh-re-inline-mmdrop kernel/fork.c
--- a/kernel/fork.c~include-linux-sched-mmh-re-inline-mmdrop
+++ a/kernel/fork.c
@@ -592,7 +592,7 @@ static void check_mm(struct mm_struct *m
* 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 *m
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)
{
_
--
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