diff options
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 6df0ae19781..f409529ff35 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -484,6 +484,13 @@ static inline void rcu_preempt_sleep_check(void) * NULL. Although rcu_access_pointer() may also be used in cases where * update-side locks prevent the value of the pointer from changing, you * should instead use rcu_dereference_protected() for this use case. + * + * It is also permissible to use rcu_access_pointer() when read-side + * access to the pointer was removed at least one grace period ago, as + * is the case in the context of the RCU callback that is freeing up + * the data, or after a synchronize_rcu() returns. This can be useful + * when tearing down multi-linked structures after a grace period + * has elapsed. */ #define rcu_access_pointer(p) __rcu_access_pointer((p), __rcu) |