From: Peter Zijlstra <[email protected]> commit e33886b38cc82a9fc3b2d655dfc7f50467594138 upstream.
Add two helpers to make it easier to treat the refcount as boolean. [js] do not involve WARN_ON_ONCE as it causes build failures Suggested-by: Jason Baron <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> [wt: only backported for use in next fix ; s/static_key_count(key)/atomic_read(&key->enabled)/] Signed-off-by: Willy Tarreau <[email protected]> --- include/linux/jump_label.h | 16 ++++++++++++++++ kernel/sched/core.c | 6 ++---- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 0976fc4..7f831b2 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -208,4 +208,20 @@ static inline bool static_key_enabled(struct static_key *key) return (atomic_read(&key->enabled) > 0); } +static inline void static_key_enable(struct static_key *key) +{ + int count = atomic_read(&key->enabled); + + if (!count) + static_key_slow_inc(key); +} + +static inline void static_key_disable(struct static_key *key) +{ + int count = atomic_read(&key->enabled); + + if (count) + static_key_slow_dec(key); +} + #endif /* _LINUX_JUMP_LABEL_H */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 6a366f9..506e56e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -179,14 +179,12 @@ struct static_key sched_feat_keys[__SCHED_FEAT_NR] = { static void sched_feat_disable(int i) { - if (static_key_enabled(&sched_feat_keys[i])) - static_key_slow_dec(&sched_feat_keys[i]); + static_key_disable(&sched_feat_keys[i]); } static void sched_feat_enable(int i) { - if (!static_key_enabled(&sched_feat_keys[i])) - static_key_slow_inc(&sched_feat_keys[i]); + static_key_enable(&sched_feat_keys[i]); } #else static void sched_feat_disable(int i) { }; -- 2.8.0.rc2.1.gbe9624a
