GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-06-20 21:51:05 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

locking, rwsem: Annotate inner lock as raw

Browse source 
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
Download patch file Download diff file Expand all files Collapse all files

38
lib/rwsem-spinlock.c
View file

@ -22,9 +22,9 @@ int rwsem_is_locked(struct rw_semaphore *sem)
int ret = 1;
unsigned long flags;
if (spin_trylock_irqsave(&sem->wait_lock, flags)) {
if (raw_spin_trylock_irqsave(&sem->wait_lock, flags)) {
ret = (sem->activity != 0);
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
}
return ret;
}
@ -44,7 +44,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
lockdep_init_map(&sem->dep_map, name, key, 0);
#endif
sem->activity = 0;
spin_lock_init(&sem->wait_lock);
raw_spin_lock_init(&sem->wait_lock);
INIT_LIST_HEAD(&sem->wait_list);
}
EXPORT_SYMBOL(__init_rwsem);
@ -145,12 +145,12 @@ void __sched __down_read(struct rw_semaphore *sem)
struct task_struct *tsk;
unsigned long flags;
spin_lock_irqsave(&sem->wait_lock, flags);
raw_spin_lock_irqsave(&sem->wait_lock, flags);
if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
/* granted */
sem->activity++;
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
goto out;
}
@ -165,7 +165,7 @@ void __sched __down_read(struct rw_semaphore *sem)
list_add_tail(&waiter.list, &sem->wait_list);
/* we don't need to touch the semaphore struct anymore */
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
/* wait to be given the lock */
for (;;) {
@ -189,7 +189,7 @@ int __down_read_trylock(struct rw_semaphore *sem)
int ret = 0;
spin_lock_irqsave(&sem->wait_lock, flags);
raw_spin_lock_irqsave(&sem->wait_lock, flags);
if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
/* granted */
@ -197,7 +197,7 @@ int __down_read_trylock(struct rw_semaphore *sem)
ret = 1;
}
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
return ret;
}
@ -212,12 +212,12 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
struct task_struct *tsk;
unsigned long flags;
spin_lock_irqsave(&sem->wait_lock, flags);
raw_spin_lock_irqsave(&sem->wait_lock, flags);
if (sem->activity == 0 && list_empty(&sem->wait_list)) {
/* granted */
sem->activity = -1;
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
goto out;
}
@ -232,7 +232,7 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
list_add_tail(&waiter.list, &sem->wait_list);
/* we don't need to touch the semaphore struct anymore */
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
/* wait to be given the lock */
for (;;) {
@ -260,7 +260,7 @@ int __down_write_trylock(struct rw_semaphore *sem)
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&sem->wait_lock, flags);
raw_spin_lock_irqsave(&sem->wait_lock, flags);
if (sem->activity == 0 && list_empty(&sem->wait_list)) {
/* granted */
@ -268,7 +268,7 @@ int __down_write_trylock(struct rw_semaphore *sem)
ret = 1;
}
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
return ret;
}
@ -280,12 +280,12 @@ void __up_read(struct rw_semaphore *sem)
{
unsigned long flags;
spin_lock_irqsave(&sem->wait_lock, flags);
raw_spin_lock_irqsave(&sem->wait_lock, flags);
if (--sem->activity == 0 && !list_empty(&sem->wait_list))
sem = __rwsem_wake_one_writer(sem);
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
}
/*
@ -295,13 +295,13 @@ void __up_write(struct rw_semaphore *sem)
{
unsigned long flags;
spin_lock_irqsave(&sem->wait_lock, flags);
raw_spin_lock_irqsave(&sem->wait_lock, flags);
sem->activity = 0;
if (!list_empty(&sem->wait_list))
sem = __rwsem_do_wake(sem, 1);
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
}
/*
@ -312,12 +312,12 @@ void __downgrade_write(struct rw_semaphore *sem)
{
unsigned long flags;
spin_lock_irqsave(&sem->wait_lock, flags);
raw_spin_lock_irqsave(&sem->wait_lock, flags);
sem->activity = 1;
if (!list_empty(&sem->wait_list))
sem = __rwsem_do_wake(sem, 0);
spin_unlock_irqrestore(&sem->wait_lock, flags);
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
}