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locking, rwsem: Annotate inner lock as raw

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There is no reason to allow the lock protecting rwsems (the
ownerless variant) to be preemptible on -rt. Convert it to raw.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner
2010-02-24 09:54:54 +01:00
committed by Ingo Molnar
parent 8292c9e15c
commit ddb6c9b58a
4 changed files with 33 additions and 31 deletions
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14
lib/rwsem.c
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@@ -22,7 +22,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
lockdep_init_map(&sem->dep_map, name, key, 0);
#endif
sem->count = RWSEM_UNLOCKED_VALUE;
spin_lock_init(&sem->wait_lock);
raw_spin_lock_init(&sem->wait_lock);
INIT_LIST_HEAD(&sem->wait_list);
}
@@ -180,7 +180,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
/* set up my own style of waitqueue */
spin_lock_irq(&sem->wait_lock);
raw_spin_lock_irq(&sem->wait_lock);
waiter.task = tsk;
waiter.flags = flags;
get_task_struct(tsk);
@@ -204,7 +204,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
adjustment == -RWSEM_ACTIVE_WRITE_BIAS)
sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED);
spin_unlock_irq(&sem->wait_lock);
raw_spin_unlock_irq(&sem->wait_lock);
/* wait to be given the lock */
for (;;) {
@@ -245,13 +245,13 @@ struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
{
unsigned long flags;
spin_lock_irqsave(&sem->wait_lock, flags);
raw_spin_lock_irqsave(&sem->wait_lock, flags);
/* do nothing if list empty */
if (!list_empty(&sem->wait_list))
sem = __rwsem_do_wake(sem, RWSEM_WAKE_ANY);
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
return sem;
}
@@ -265,13 +265,13 @@ struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
{
unsigned long flags;
spin_lock_irqsave(&sem->wait_lock, flags);
raw_spin_lock_irqsave(&sem->wait_lock, flags);
/* do nothing if list empty */
if (!list_empty(&sem->wait_list))
sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED);
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
return sem;
}