diff options
Diffstat (limited to 'include/linux/rcupdate.h')
-rw-r--r-- | include/linux/rcupdate.h | 38 |
1 files changed, 34 insertions, 4 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 51b26ab02878..d15d46db61f7 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -877,12 +877,42 @@ do { \ /** * kvfree_rcu() - kvfree an object after a grace period. - * @ptr: pointer to kvfree - * @rhf: the name of the struct rcu_head within the type of @ptr. * - * Same as kfree_rcu(), just simple alias. + * This macro consists of one or two arguments and it is + * based on whether an object is head-less or not. If it + * has a head then a semantic stays the same as it used + * to be before: + * + * kvfree_rcu(ptr, rhf); + * + * where @ptr is a pointer to kvfree(), @rhf is the name + * of the rcu_head structure within the type of @ptr. + * + * When it comes to head-less variant, only one argument + * is passed and that is just a pointer which has to be + * freed after a grace period. Therefore the semantic is + * + * kvfree_rcu(ptr); + * + * where @ptr is a pointer to kvfree(). + * + * Please note, head-less way of freeing is permitted to + * use from a context that has to follow might_sleep() + * annotation. Otherwise, please switch and embed the + * rcu_head structure within the type of @ptr. */ -#define kvfree_rcu(ptr, rhf) kfree_rcu(ptr, rhf) +#define kvfree_rcu(...) KVFREE_GET_MACRO(__VA_ARGS__, \ + kvfree_rcu_arg_2, kvfree_rcu_arg_1)(__VA_ARGS__) + +#define KVFREE_GET_MACRO(_1, _2, NAME, ...) NAME +#define kvfree_rcu_arg_2(ptr, rhf) kfree_rcu(ptr, rhf) +#define kvfree_rcu_arg_1(ptr) \ +do { \ + typeof(ptr) ___p = (ptr); \ + \ + if (___p) \ + kvfree_call_rcu(NULL, (rcu_callback_t) (___p)); \ +} while (0) /* * Place this after a lock-acquisition primitive to guarantee that |