rcu: Introduce kfree_rcu() single-argument macro
authorUladzislau Rezki (Sony) <urezki@gmail.com>
Fri, 20 Nov 2020 11:49:16 +0000 (12:49 +0100)
committerPaul E. McKenney <paulmck@kernel.org>
Mon, 4 Jan 2021 21:42:04 +0000 (13:42 -0800)
There is a kvfree_rcu() single argument macro that handles pointers
returned by kvmalloc(). Even though it also handles pointer returned by
kmalloc(), readability suffers.

This commit therefore updates the kfree_rcu() macro to explicitly pair
with kmalloc(), thus improving readability.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
include/linux/rcupdate.h

index de08264..b95373e 100644 (file)
@@ -851,8 +851,9 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
 
 /**
  * kfree_rcu() - kfree an object after a grace period.
- * @ptr:       pointer to kfree
- * @rhf:       the name of the struct rcu_head within the type of @ptr.
+ * @ptr: pointer to kfree for both single- and double-argument invocations.
+ * @rhf: the name of the struct rcu_head within the type of @ptr,
+ *       but only for double-argument invocations.
  *
  * Many rcu callbacks functions just call kfree() on the base structure.
  * These functions are trivial, but their size adds up, and furthermore
@@ -875,13 +876,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
  * The BUILD_BUG_ON check must not involve any function calls, hence the
  * checks are done in macros here.
  */
-#define kfree_rcu(ptr, rhf)                                            \
-do {                                                                   \
-       typeof (ptr) ___p = (ptr);                                      \
-                                                                       \
-       if (___p)                                                       \
-               __kvfree_rcu(&((___p)->rhf), offsetof(typeof(*(ptr)), rhf)); \
-} while (0)
+#define kfree_rcu kvfree_rcu
 
 /**
  * kvfree_rcu() - kvfree an object after a grace period.
@@ -913,7 +908,14 @@ do {                                                                       \
        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_2(ptr, rhf)                                     \
+do {                                                                   \
+       typeof (ptr) ___p = (ptr);                                      \
+                                                                       \
+       if (___p)                                                       \
+               __kvfree_rcu(&((___p)->rhf), offsetof(typeof(*(ptr)), rhf)); \
+} while (0)
+
 #define kvfree_rcu_arg_1(ptr)                                  \
 do {                                                           \
        typeof(ptr) ___p = (ptr);                               \