patch-2.4.4 linux/arch/ia64/kernel/semaphore.c

• Lines: 181
• Date: Tue Apr 17 17:19:24 2001
• Orig file: v2.4.3/linux/arch/ia64/kernel/semaphore.c
• Orig date: Sat Nov 11 19:02:40 2000

diff -u --recursive --new-file v2.4.3/linux/arch/ia64/kernel/semaphore.c linux/arch/ia64/kernel/semaphore.c
@@ -155,180 +155,3 @@
 	spin_unlock_irqrestore(&semaphore_lock, flags);
 	return 1;
 }
-
-/*
- * Helper routines for rw semaphores.  These could be optimized some
- * more, but since they're off the critical path, I prefer clarity for
- * now...
- */
-
-/*
- * This gets called if we failed to acquire the lock, but we're biased
- * to acquire the lock by virtue of causing the count to change from 0
- * to -1.  Being biased, we sleep and attempt to grab the lock until
- * we succeed.  When this function returns, we own the lock.
- */
-static inline void
-down_read_failed_biased (struct rw_semaphore *sem)
-{
-	struct task_struct *tsk = current;
-	DECLARE_WAITQUEUE(wait, tsk);
-
-	add_wait_queue(&sem->wait, &wait);	/* put ourselves at the head of the list */
-
-	for (;;) {
-		if (sem->read_bias_granted && xchg(&sem->read_bias_granted, 0))
-			break;
-		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
-		if (!sem->read_bias_granted)
-			schedule();
-	}
-	remove_wait_queue(&sem->wait, &wait);
-	tsk->state = TASK_RUNNING;
-}
-
-/*
- * This gets called if we failed to acquire the lock and we are not
- * biased to acquire the lock.  We undo the decrement that was
- * done earlier, go to sleep, and then attempt to re-acquire the
- * lock afterwards.
- */
-static inline void
-down_read_failed (struct rw_semaphore *sem)
-{
-	struct task_struct *tsk = current;
-	DECLARE_WAITQUEUE(wait, tsk);
-
-	/*
-	 * Undo the decrement we did in down_read() and check if we
-	 * need to wake up someone.
-	 */
-	__up_read(sem);
-
-	add_wait_queue(&sem->wait, &wait);
-	while (sem->count < 0) {
-		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
-		if (sem->count >= 0)
-			break;
-		schedule();
-	}
-	remove_wait_queue(&sem->wait, &wait);
-	tsk->state = TASK_RUNNING;
-}
-
-/*
- * Wait for the lock to become unbiased.  Readers are non-exclusive.
- */
-void
-__down_read_failed (struct rw_semaphore *sem, long count)
-{
-	while (1) {
-		if (count == -1) {
-			down_read_failed_biased(sem);
-			return;
-		}
-		/* unbiased */
-		down_read_failed(sem);
-
-		count = ia64_fetch_and_add(-1, &sem->count);
-		if (count >= 0)
-			return;
-	}
-}
-
-static inline void
-down_write_failed_biased (struct rw_semaphore *sem)
-{
-	struct task_struct *tsk = current;
-	DECLARE_WAITQUEUE(wait, tsk);
-
-	/* put ourselves at the end of the list */
-	add_wait_queue_exclusive(&sem->write_bias_wait, &wait);
-
-	for (;;) {
-		if (sem->write_bias_granted && xchg(&sem->write_bias_granted, 0))
-			break;
-		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
-		if (!sem->write_bias_granted)
-			schedule();
-	}
-
-	remove_wait_queue(&sem->write_bias_wait, &wait);
-	tsk->state = TASK_RUNNING;
-
-	/*
-	 * If the lock is currently unbiased, awaken the sleepers
-	 * FIXME: this wakes up the readers early in a bit of a
-	 * stampede -> bad!
-	 */
-	if (sem->count >= 0)
-		wake_up(&sem->wait);
-}
-
-
-static inline void
-down_write_failed (struct rw_semaphore *sem)
-{
-	struct task_struct *tsk = current;
-	DECLARE_WAITQUEUE(wait, tsk);
-
-	__up_write(sem);	/* this takes care of granting the lock */
-
-	add_wait_queue_exclusive(&sem->wait, &wait);
-
-	while (sem->count < 0) {
-		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
-		if (sem->count >= 0)
-			break;	/* we must attempt to acquire or bias the lock */
-		schedule();
-	}
-
-	remove_wait_queue(&sem->wait, &wait);
-	tsk->state = TASK_RUNNING;
-}
-
-
-/*
- * Wait for the lock to become unbiased.  Since we're a writer, we'll
- * make ourselves exclusive.
- */
-void
-__down_write_failed (struct rw_semaphore *sem, long count)
-{
-	long old_count;
-
-	while (1) {
-		if (count == -RW_LOCK_BIAS) {
-			down_write_failed_biased(sem);
-			return;
-		}
-		down_write_failed(sem);
-
-		do {
-			old_count = sem->count;
-			count = old_count - RW_LOCK_BIAS;
-		} while (cmpxchg_acq(&sem->count, old_count, count) != old_count);
-
-		if (count == 0)
-			return;
-	}
-}
-
-void
-__rwsem_wake (struct rw_semaphore *sem, long count)
-{
-	wait_queue_head_t *wq;
-
-	if (count == 0) {
-		/* wake a writer */
-		if (xchg(&sem->write_bias_granted, 1))
-			BUG();
-		wq = &sem->write_bias_wait;
-	} else {
-		/* wake reader(s) */
-		if (xchg(&sem->read_bias_granted, 1))
-			BUG();
-		wq = &sem->wait;
-	}
-	wake_up(wq);	/* wake up everyone on the wait queue */
-}