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| author | Peter Zijlstra <peterz@infradead.org> | 2016-11-14 18:03:11 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-01-18 10:03:29 +0100 |
| commit | 0a13cd1a05e7a549259d4f803d2ec2efda07ed7c (patch) | |
| tree | 8d8799d8a46d827a689e9939d472654b307e16c8 /include/linux/kref.h | |
| parent | 23b19ec3377924eb8f303880102e056e9214ba72 (diff) | |
| download | linux-0a13cd1a05e7a549259d4f803d2ec2efda07ed7c.tar.gz linux-0a13cd1a05e7a549259d4f803d2ec2efda07ed7c.tar.bz2 linux-0a13cd1a05e7a549259d4f803d2ec2efda07ed7c.zip | |
locking/atomic, kref: Implement kref_put_lock()
Because home-rolling your own is _awesome_, stop doing it. Provide
kref_put_lock(), just like kref_put_mutex() but for a spinlock.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/kref.h')
| -rw-r--r-- | include/linux/kref.h | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/include/linux/kref.h b/include/linux/kref.h index 31c49a64cdf9..9db9685fed84 100644 --- a/include/linux/kref.h +++ b/include/linux/kref.h @@ -19,6 +19,7 @@ #include <linux/atomic.h> #include <linux/kernel.h> #include <linux/mutex.h> +#include <linux/spinlock.h> struct kref { atomic_t refcount; @@ -86,12 +87,21 @@ static inline int kref_put_mutex(struct kref *kref, struct mutex *lock) { WARN_ON(release == NULL); - if (unlikely(!atomic_add_unless(&kref->refcount, -1, 1))) { - mutex_lock(lock); - if (unlikely(!atomic_dec_and_test(&kref->refcount))) { - mutex_unlock(lock); - return 0; - } + + if (atomic_dec_and_mutex_lock(&kref->refcount, lock)) { + release(kref); + return 1; + } + return 0; +} + +static inline int kref_put_lock(struct kref *kref, + void (*release)(struct kref *kref), + spinlock_t *lock) +{ + WARN_ON(release == NULL); + + if (atomic_dec_and_lock(&kref->refcount, lock)) { release(kref); return 1; } |