diff options
Diffstat (limited to 'kernel/locking/rwsem-xadd.c')
| -rw-r--r-- | kernel/locking/rwsem-xadd.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index dacc321..a2391ac 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -82,9 +82,9 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, sem->count = RWSEM_UNLOCKED_VALUE; raw_spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); -#ifdef CONFIG_SMP +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER sem->owner = NULL; - sem->osq = NULL; + osq_lock_init(&sem->osq); #endif } @@ -262,7 +262,7 @@ static inline bool rwsem_try_write_lock(long count, struct rw_semaphore *sem) return false; } -#ifdef CONFIG_SMP +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER /* * Try to acquire write lock before the writer has been put on wait queue. */ @@ -285,10 +285,10 @@ static inline bool rwsem_try_write_lock_unqueued(struct rw_semaphore *sem) static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem) { struct task_struct *owner; - bool on_cpu = true; + bool on_cpu = false; if (need_resched()) - return 0; + return false; rcu_read_lock(); owner = ACCESS_ONCE(sem->owner); @@ -297,9 +297,9 @@ static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem) rcu_read_unlock(); /* - * If sem->owner is not set, the rwsem owner may have - * just acquired it and not set the owner yet or the rwsem - * has been released. + * If sem->owner is not set, yet we have just recently entered the + * slowpath, then there is a possibility reader(s) may have the lock. + * To be safe, avoid spinning in these situations. */ return on_cpu; } |
