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-rw-r--r--kernel/jump_label.c63
1 files changed, 36 insertions, 27 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index bad96b476eb6..de6efdecc70d 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -202,11 +202,13 @@ void static_key_disable(struct static_key *key)
}
EXPORT_SYMBOL_GPL(static_key_disable);
-static void __static_key_slow_dec_cpuslocked(struct static_key *key,
- unsigned long rate_limit,
- struct delayed_work *work)
+static bool static_key_slow_try_dec(struct static_key *key)
{
- lockdep_assert_cpus_held();
+ int val;
+
+ val = atomic_fetch_add_unless(&key->enabled, -1, 1);
+ if (val == 1)
+ return false;
/*
* The negative count check is valid even when a negative
@@ -215,63 +217,70 @@ static void __static_key_slow_dec_cpuslocked(struct static_key *key,
* returns is unbalanced, because all other static_key_slow_inc()
* instances block while the update is in progress.
*/
- if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) {
- WARN(atomic_read(&key->enabled) < 0,
- "jump label: negative count!\n");
+ WARN(val < 0, "jump label: negative count!\n");
+ return true;
+}
+
+static void __static_key_slow_dec_cpuslocked(struct static_key *key)
+{
+ lockdep_assert_cpus_held();
+
+ if (static_key_slow_try_dec(key))
return;
- }
- if (rate_limit) {
- atomic_inc(&key->enabled);
- schedule_delayed_work(work, rate_limit);
- } else {
+ jump_label_lock();
+ if (atomic_dec_and_test(&key->enabled))
jump_label_update(key);
- }
jump_label_unlock();
}
-static void __static_key_slow_dec(struct static_key *key,
- unsigned long rate_limit,
- struct delayed_work *work)
+static void __static_key_slow_dec(struct static_key *key)
{
cpus_read_lock();
- __static_key_slow_dec_cpuslocked(key, rate_limit, work);
+ __static_key_slow_dec_cpuslocked(key);
cpus_read_unlock();
}
-static void jump_label_update_timeout(struct work_struct *work)
+void jump_label_update_timeout(struct work_struct *work)
{
struct static_key_deferred *key =
container_of(work, struct static_key_deferred, work.work);
- __static_key_slow_dec(&key->key, 0, NULL);
+ __static_key_slow_dec(&key->key);
}
+EXPORT_SYMBOL_GPL(jump_label_update_timeout);
void static_key_slow_dec(struct static_key *key)
{
STATIC_KEY_CHECK_USE(key);
- __static_key_slow_dec(key, 0, NULL);
+ __static_key_slow_dec(key);
}
EXPORT_SYMBOL_GPL(static_key_slow_dec);
void static_key_slow_dec_cpuslocked(struct static_key *key)
{
STATIC_KEY_CHECK_USE(key);
- __static_key_slow_dec_cpuslocked(key, 0, NULL);
+ __static_key_slow_dec_cpuslocked(key);
}
-void static_key_slow_dec_deferred(struct static_key_deferred *key)
+void __static_key_slow_dec_deferred(struct static_key *key,
+ struct delayed_work *work,
+ unsigned long timeout)
{
STATIC_KEY_CHECK_USE(key);
- __static_key_slow_dec(&key->key, key->timeout, &key->work);
+
+ if (static_key_slow_try_dec(key))
+ return;
+
+ schedule_delayed_work(work, timeout);
}
-EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred);
+EXPORT_SYMBOL_GPL(__static_key_slow_dec_deferred);
-void static_key_deferred_flush(struct static_key_deferred *key)
+void __static_key_deferred_flush(void *key, struct delayed_work *work)
{
STATIC_KEY_CHECK_USE(key);
- flush_delayed_work(&key->work);
+ flush_delayed_work(work);
}
-EXPORT_SYMBOL_GPL(static_key_deferred_flush);
+EXPORT_SYMBOL_GPL(__static_key_deferred_flush);
void jump_label_rate_limit(struct static_key_deferred *key,
unsigned long rl)