From: Mel Gorman <mgorman@xxxxxxx>
This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.
===============
commit ea5e9539abf1258f23e725cb9cb25aa74efa29eb upstream.
This patch exposes the jump_label reference count in preparation for the
next patch. cpusets cares about both the jump_label being enabled and how
many users of the cpusets there currently are.
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
include/linux/jump_label.h | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index a5079072da66..9216e465289a 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -62,6 +62,10 @@ struct static_key {
# include <asm/jump_label.h>
# define HAVE_JUMP_LABEL
+#else
+struct static_key {
+ atomic_t enabled;
+};
#endif /* CC_HAVE_ASM_GOTO && CONFIG_JUMP_LABEL */
enum jump_label_type {
@@ -72,6 +76,12 @@ enum jump_label_type {
struct module;
#include <linux/atomic.h>
+
+static inline int static_key_count(struct static_key *key)
+{
+ return atomic_read(&key->enabled);
+}
+
#ifdef HAVE_JUMP_LABEL
#define JUMP_LABEL_TRUE_BRANCH 1UL
@@ -122,24 +132,20 @@ extern void jump_label_apply_nops(struct module *mod);
#else /* !HAVE_JUMP_LABEL */
-struct static_key {
- atomic_t enabled;
-};
-
static __always_inline void jump_label_init(void)
{
}
static __always_inline bool static_key_false(struct static_key *key)
{
- if (unlikely(atomic_read(&key->enabled)) > 0)
+ if (unlikely(static_key_count(key) > 0))
return true;
return false;
}
static __always_inline bool static_key_true(struct static_key *key)
{
- if (likely(atomic_read(&key->enabled)) > 0)
+ if (likely(static_key_count(key) > 0))
return true;
return false;
}
@@ -179,7 +185,7 @@ static inline int jump_label_apply_nops(struct module *mod)
static inline bool static_key_enabled(struct static_key *key)
{
- return (atomic_read(&key->enabled) > 0);
+ return static_key_count(key) > 0;
}
#endif /* _LINUX_JUMP_LABEL_H */
--
2.1.0
--
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