diff options
Diffstat (limited to 'include/linux/spinlock.h')
| -rw-r--r-- | include/linux/spinlock.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 31d3d747a9db..0c71f06454d9 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -449,6 +449,37 @@ static __always_inline int spin_is_contended(spinlock_t *lock) return raw_spin_is_contended(&lock->rlock); } +/* + * Does a critical section need to be broken due to another + * task waiting?: (technically does not depend on CONFIG_PREEMPTION, + * but a general need for low latency) + */ +static inline int spin_needbreak(spinlock_t *lock) +{ +#ifdef CONFIG_PREEMPTION + return spin_is_contended(lock); +#else + return 0; +#endif +} + +/* + * Check if a rwlock is contended. + * Returns non-zero if there is another task waiting on the rwlock. + * Returns zero if the lock is not contended or the system / underlying + * rwlock implementation does not support contention detection. + * Technically does not depend on CONFIG_PREEMPTION, but a general need + * for low latency. + */ +static inline int rwlock_needbreak(rwlock_t *lock) +{ +#ifdef CONFIG_PREEMPTION + return rwlock_is_contended(lock); +#else + return 0; +#endif +} + #define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) #else /* !CONFIG_PREEMPT_RT */ |