From: Eric Biggers <ebigg...@google.com>
Switch the DO_ONCE() macro from the deprecated jump label API to the new
one. The new one is more readable, and for DO_ONCE() it also makes the
generated code more icache-friendly: now the one-time initialization
code is placed out-of-line at the jump target, rather than at the inline
fallthrough case.
Acked-by: Hannes Frederic Sowa <han...@stressinduktion.org>
Signed-off-by: Eric Biggers <ebigg...@google.com>
---
include/linux/once.h | 6 +++---
lib/once.c | 8 ++++----
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/include/linux/once.h b/include/linux/once.h
index 9c98aaa87cbc..724724918e8b 100644
--- a/include/linux/once.h
+++ b/include/linux/once.h
@@ -5,7 +5,7 @@
#include <linux/jump_label.h>
bool __do_once_start(bool *done, unsigned long *flags);
-void __do_once_done(bool *done, struct static_key *once_key,
+void __do_once_done(bool *done, struct static_key_true *once_key,
unsigned long *flags);
/* Call a function exactly once. The idea of DO_ONCE() is to perform
@@ -38,8 +38,8 @@ void __do_once_done(bool *done, struct static_key *once_key,
({ \
bool ___ret = false; \
static bool ___done = false; \
- static struct static_key ___once_key = STATIC_KEY_INIT_TRUE; \
- if (static_key_true(&___once_key)) { \
+ static DEFINE_STATIC_KEY_TRUE(___once_key); \
+ if (static_branch_unlikely(&___once_key)) { \
unsigned long ___flags; \
___ret = __do_once_start(&___done, &___flags); \
if (unlikely(___ret)) { \
diff --git a/lib/once.c b/lib/once.c
index 05c8604627eb..831c5a6b0bb2 100644
--- a/lib/once.c
+++ b/lib/once.c
@@ -5,7 +5,7 @@
struct once_work {
struct work_struct work;
- struct static_key *key;
+ struct static_key_true *key;
};
static void once_deferred(struct work_struct *w)
@@ -14,11 +14,11 @@ static void once_deferred(struct work_struct *w)
work = container_of(w, struct once_work, work);
BUG_ON(!static_key_enabled(work->key));
- static_key_slow_dec(work->key);
+ static_branch_disable(work->key);
kfree(work);
}
-static void once_disable_jump(struct static_key *key)
+static void once_disable_jump(struct static_key_true *key)
{
struct once_work *w;
@@ -51,7 +51,7 @@ bool __do_once_start(bool *done, unsigned long *flags)
}
EXPORT_SYMBOL(__do_once_start);
-void __do_once_done(bool *done, struct static_key *once_key,
+void __do_once_done(bool *done, struct static_key_true *once_key,
unsigned long *flags)
__releases(once_lock)
{
--
2.14.2.920.gcf0c67979c-goog
