diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/semaphore.c | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/kernel/semaphore.c b/kernel/semaphore.c index 2da2aed950f3..5a12a8558982 100644 --- a/kernel/semaphore.c +++ b/kernel/semaphore.c @@ -35,6 +35,7 @@ static noinline void __down(struct semaphore *sem); static noinline int __down_interruptible(struct semaphore *sem); static noinline int __down_killable(struct semaphore *sem); +static noinline int __down_timeout(struct semaphore *sem, long jiffies); static noinline void __up(struct semaphore *sem); void down(struct semaphore *sem) @@ -104,6 +105,20 @@ int down_trylock(struct semaphore *sem) } EXPORT_SYMBOL(down_trylock); +int down_timeout(struct semaphore *sem, long jiffies) +{ + unsigned long flags; + int result = 0; + + spin_lock_irqsave(&sem->lock, flags); + if (unlikely(sem->count-- <= 0)) + result = __down_timeout(sem, jiffies); + spin_unlock_irqrestore(&sem->lock, flags); + + return result; +} +EXPORT_SYMBOL(down_timeout); + void up(struct semaphore *sem) { unsigned long flags; @@ -142,10 +157,12 @@ static noinline void __sched __up_down_common(struct semaphore *sem) } /* - * Because this function is inlined, the 'state' parameter will be constant, - * and thus optimised away by the compiler. + * Because this function is inlined, the 'state' parameter will be + * constant, and thus optimised away by the compiler. Likewise the + * 'timeout' parameter for the cases without timeouts. */ -static inline int __sched __down_common(struct semaphore *sem, long state) +static inline int __sched __down_common(struct semaphore *sem, long state, + long timeout) { int result = 0; struct task_struct *task = current; @@ -160,14 +177,20 @@ static inline int __sched __down_common(struct semaphore *sem, long state) goto interrupted; if (state == TASK_KILLABLE && fatal_signal_pending(task)) goto interrupted; + if (timeout <= 0) + goto timed_out; __set_task_state(task, state); spin_unlock_irq(&sem->lock); - schedule(); + timeout = schedule_timeout(timeout); spin_lock_irq(&sem->lock); if (waiter.up) goto woken; } + timed_out: + list_del(&waiter.list); + result = -ETIME; + goto woken; interrupted: list_del(&waiter.list); result = -EINTR; @@ -187,17 +210,22 @@ static inline int __sched __down_common(struct semaphore *sem, long state) static noinline void __sched __down(struct semaphore *sem) { - __down_common(sem, TASK_UNINTERRUPTIBLE); + __down_common(sem, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); } static noinline int __sched __down_interruptible(struct semaphore *sem) { - return __down_common(sem, TASK_INTERRUPTIBLE); + return __down_common(sem, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); } static noinline int __sched __down_killable(struct semaphore *sem) { - return __down_common(sem, TASK_KILLABLE); + return __down_common(sem, TASK_KILLABLE, MAX_SCHEDULE_TIMEOUT); +} + +static noinline int __sched __down_timeout(struct semaphore *sem, long jiffies) +{ + return __down_common(sem, TASK_UNINTERRUPTIBLE, jiffies); } static noinline void __sched __up(struct semaphore *sem) |