diff options
| -rw-r--r-- | include/linux/rcupdate.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 6c3ceceb6148..587eb057e2fa 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -813,6 +813,28 @@ static inline void rcu_preempt_sleep_check(void) #define rcu_dereference_sched(p) rcu_dereference_sched_check(p, 0) /** + * rcu_pointer_handoff() - Hand off a pointer from RCU to other mechanism + * @p: The pointer to hand off + * + * This is simply an identity function, but it documents where a pointer + * is handed off from RCU to some other synchronization mechanism, for + * example, reference counting or locking. In C11, it would map to + * kill_dependency(). It could be used as follows: + * + * rcu_read_lock(); + * p = rcu_dereference(gp); + * long_lived = is_long_lived(p); + * if (long_lived) { + * if (!atomic_inc_not_zero(p->refcnt)) + * long_lived = false; + * else + * p = rcu_pointer_handoff(p); + * } + * rcu_read_unlock(); + */ +#define rcu_pointer_handoff(p) (p) + +/** * rcu_read_lock() - mark the beginning of an RCU read-side critical section * * When synchronize_rcu() is invoked on one CPU while other CPUs |