diff options
Diffstat (limited to 'lib/rwsem.c')
| -rw-r--r-- | lib/rwsem.c | 22 |
1 files changed, 2 insertions, 20 deletions
diff --git a/lib/rwsem.c b/lib/rwsem.c index fb658af1c12c..66f307e90761 100644 --- a/lib/rwsem.c +++ b/lib/rwsem.c @@ -182,7 +182,6 @@ try_again_write: */ struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem) { - enum rwsem_waiter_type type = RWSEM_WAITING_FOR_READ; signed long adjustment = -RWSEM_ACTIVE_READ_BIAS; struct rwsem_waiter waiter; struct task_struct *tsk = current; @@ -190,7 +189,7 @@ struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem) /* set up my own style of waitqueue */ waiter.task = tsk; - waiter.type = type; + waiter.type = RWSEM_WAITING_FOR_READ; get_task_struct(tsk); raw_spin_lock_irq(&sem->wait_lock); @@ -201,17 +200,9 @@ struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem) /* we're now waiting on the lock, but no longer actively locking */ count = rwsem_atomic_update(adjustment, sem); - /* If there are no active locks, wake the front queued process(es) up. - * - * Alternatively, if we're called from a failed down_write(), there - * were already threads queued before us and there are no active - * writers, the lock must be read owned; so we try to wake any read - * locks that were queued ahead of us. */ + /* If there are no active locks, wake the front queued process(es). */ if (count == RWSEM_WAITING_BIAS) sem = __rwsem_do_wake(sem, RWSEM_WAKE_NO_ACTIVE); - else if (count > RWSEM_WAITING_BIAS && - adjustment == -RWSEM_ACTIVE_WRITE_BIAS) - sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED); raw_spin_unlock_irq(&sem->wait_lock); @@ -220,15 +211,6 @@ struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem) set_task_state(tsk, TASK_UNINTERRUPTIBLE); if (!waiter.task) break; - - raw_spin_lock_irq(&sem->wait_lock); - /* Try to get the writer sem, may steal from the head writer: */ - if (type == RWSEM_WAITING_FOR_WRITE) - if (try_get_writer_sem(sem, &waiter)) { - raw_spin_unlock_irq(&sem->wait_lock); - return sem; - } - raw_spin_unlock_irq(&sem->wait_lock); schedule(); } |