locking, rwsem: Annotate inner lock as raw
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:
Родитель
8292c9e15c
Коммит
ddb6c9b58a
|
@ -22,7 +22,7 @@
|
||||||
*/
|
*/
|
||||||
struct rw_semaphore {
|
struct rw_semaphore {
|
||||||
__s32 activity;
|
__s32 activity;
|
||||||
spinlock_t wait_lock;
|
raw_spinlock_t wait_lock;
|
||||||
struct list_head wait_list;
|
struct list_head wait_list;
|
||||||
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
||||||
struct lockdep_map dep_map;
|
struct lockdep_map dep_map;
|
||||||
|
|
|
@ -25,7 +25,7 @@ struct rw_semaphore;
|
||||||
/* All arch specific implementations share the same struct */
|
/* All arch specific implementations share the same struct */
|
||||||
struct rw_semaphore {
|
struct rw_semaphore {
|
||||||
long count;
|
long count;
|
||||||
spinlock_t wait_lock;
|
raw_spinlock_t wait_lock;
|
||||||
struct list_head wait_list;
|
struct list_head wait_list;
|
||||||
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
||||||
struct lockdep_map dep_map;
|
struct lockdep_map dep_map;
|
||||||
|
@ -56,9 +56,11 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem)
|
||||||
# define __RWSEM_DEP_MAP_INIT(lockname)
|
# define __RWSEM_DEP_MAP_INIT(lockname)
|
||||||
#endif
|
#endif
|
||||||
|
|
||||||
#define __RWSEM_INITIALIZER(name) \
|
#define __RWSEM_INITIALIZER(name) \
|
||||||
{ RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED(name.wait_lock), \
|
{ RWSEM_UNLOCKED_VALUE, \
|
||||||
LIST_HEAD_INIT((name).wait_list) __RWSEM_DEP_MAP_INIT(name) }
|
__RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
|
||||||
|
LIST_HEAD_INIT((name).wait_list) \
|
||||||
|
__RWSEM_DEP_MAP_INIT(name) }
|
||||||
|
|
||||||
#define DECLARE_RWSEM(name) \
|
#define DECLARE_RWSEM(name) \
|
||||||
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
|
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
|
||||||
|
|
|
@ -22,9 +22,9 @@ int rwsem_is_locked(struct rw_semaphore *sem)
|
||||||
int ret = 1;
|
int ret = 1;
|
||||||
unsigned long flags;
|
unsigned long flags;
|
||||||
|
|
||||||
if (spin_trylock_irqsave(&sem->wait_lock, flags)) {
|
if (raw_spin_trylock_irqsave(&sem->wait_lock, flags)) {
|
||||||
ret = (sem->activity != 0);
|
ret = (sem->activity != 0);
|
||||||
spin_unlock_irqrestore(&sem->wait_lock, flags);
|
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
|
||||||
}
|
}
|
||||||
return ret;
|
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);
|
lockdep_init_map(&sem->dep_map, name, key, 0);
|
||||||
#endif
|
#endif
|
||||||
sem->activity = 0;
|
sem->activity = 0;
|
||||||
spin_lock_init(&sem->wait_lock);
|
raw_spin_lock_init(&sem->wait_lock);
|
||||||
INIT_LIST_HEAD(&sem->wait_list);
|
INIT_LIST_HEAD(&sem->wait_list);
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL(__init_rwsem);
|
EXPORT_SYMBOL(__init_rwsem);
|
||||||
|
@ -145,12 +145,12 @@ void __sched __down_read(struct rw_semaphore *sem)
|
||||||
struct task_struct *tsk;
|
struct task_struct *tsk;
|
||||||
unsigned long flags;
|
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)) {
|
if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
|
||||||
/* granted */
|
/* granted */
|
||||||
sem->activity++;
|
sem->activity++;
|
||||||
spin_unlock_irqrestore(&sem->wait_lock, flags);
|
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
|
||||||
goto out;
|
goto out;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -165,7 +165,7 @@ void __sched __down_read(struct rw_semaphore *sem)
|
||||||
list_add_tail(&waiter.list, &sem->wait_list);
|
list_add_tail(&waiter.list, &sem->wait_list);
|
||||||
|
|
||||||
/* we don't need to touch the semaphore struct anymore */
|
/* 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 */
|
/* wait to be given the lock */
|
||||||
for (;;) {
|
for (;;) {
|
||||||
|
@ -189,7 +189,7 @@ int __down_read_trylock(struct rw_semaphore *sem)
|
||||||
int ret = 0;
|
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)) {
|
if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
|
||||||
/* granted */
|
/* granted */
|
||||||
|
@ -197,7 +197,7 @@ int __down_read_trylock(struct rw_semaphore *sem)
|
||||||
ret = 1;
|
ret = 1;
|
||||||
}
|
}
|
||||||
|
|
||||||
spin_unlock_irqrestore(&sem->wait_lock, flags);
|
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
|
||||||
|
|
||||||
return ret;
|
return ret;
|
||||||
}
|
}
|
||||||
|
@ -212,12 +212,12 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
|
||||||
struct task_struct *tsk;
|
struct task_struct *tsk;
|
||||||
unsigned long flags;
|
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)) {
|
if (sem->activity == 0 && list_empty(&sem->wait_list)) {
|
||||||
/* granted */
|
/* granted */
|
||||||
sem->activity = -1;
|
sem->activity = -1;
|
||||||
spin_unlock_irqrestore(&sem->wait_lock, flags);
|
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
|
||||||
goto out;
|
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);
|
list_add_tail(&waiter.list, &sem->wait_list);
|
||||||
|
|
||||||
/* we don't need to touch the semaphore struct anymore */
|
/* 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 */
|
/* wait to be given the lock */
|
||||||
for (;;) {
|
for (;;) {
|
||||||
|
@ -260,7 +260,7 @@ int __down_write_trylock(struct rw_semaphore *sem)
|
||||||
unsigned long flags;
|
unsigned long flags;
|
||||||
int ret = 0;
|
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)) {
|
if (sem->activity == 0 && list_empty(&sem->wait_list)) {
|
||||||
/* granted */
|
/* granted */
|
||||||
|
@ -268,7 +268,7 @@ int __down_write_trylock(struct rw_semaphore *sem)
|
||||||
ret = 1;
|
ret = 1;
|
||||||
}
|
}
|
||||||
|
|
||||||
spin_unlock_irqrestore(&sem->wait_lock, flags);
|
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
|
||||||
|
|
||||||
return ret;
|
return ret;
|
||||||
}
|
}
|
||||||
|
@ -280,12 +280,12 @@ void __up_read(struct rw_semaphore *sem)
|
||||||
{
|
{
|
||||||
unsigned long flags;
|
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))
|
if (--sem->activity == 0 && !list_empty(&sem->wait_list))
|
||||||
sem = __rwsem_wake_one_writer(sem);
|
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;
|
unsigned long flags;
|
||||||
|
|
||||||
spin_lock_irqsave(&sem->wait_lock, flags);
|
raw_spin_lock_irqsave(&sem->wait_lock, flags);
|
||||||
|
|
||||||
sem->activity = 0;
|
sem->activity = 0;
|
||||||
if (!list_empty(&sem->wait_list))
|
if (!list_empty(&sem->wait_list))
|
||||||
sem = __rwsem_do_wake(sem, 1);
|
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;
|
unsigned long flags;
|
||||||
|
|
||||||
spin_lock_irqsave(&sem->wait_lock, flags);
|
raw_spin_lock_irqsave(&sem->wait_lock, flags);
|
||||||
|
|
||||||
sem->activity = 1;
|
sem->activity = 1;
|
||||||
if (!list_empty(&sem->wait_list))
|
if (!list_empty(&sem->wait_list))
|
||||||
sem = __rwsem_do_wake(sem, 0);
|
sem = __rwsem_do_wake(sem, 0);
|
||||||
|
|
||||||
spin_unlock_irqrestore(&sem->wait_lock, flags);
|
raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
14
lib/rwsem.c
14
lib/rwsem.c
|
@ -22,7 +22,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
|
||||||
lockdep_init_map(&sem->dep_map, name, key, 0);
|
lockdep_init_map(&sem->dep_map, name, key, 0);
|
||||||
#endif
|
#endif
|
||||||
sem->count = RWSEM_UNLOCKED_VALUE;
|
sem->count = RWSEM_UNLOCKED_VALUE;
|
||||||
spin_lock_init(&sem->wait_lock);
|
raw_spin_lock_init(&sem->wait_lock);
|
||||||
INIT_LIST_HEAD(&sem->wait_list);
|
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_task_state(tsk, TASK_UNINTERRUPTIBLE);
|
||||||
|
|
||||||
/* set up my own style of waitqueue */
|
/* set up my own style of waitqueue */
|
||||||
spin_lock_irq(&sem->wait_lock);
|
raw_spin_lock_irq(&sem->wait_lock);
|
||||||
waiter.task = tsk;
|
waiter.task = tsk;
|
||||||
waiter.flags = flags;
|
waiter.flags = flags;
|
||||||
get_task_struct(tsk);
|
get_task_struct(tsk);
|
||||||
|
@ -204,7 +204,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
|
||||||
adjustment == -RWSEM_ACTIVE_WRITE_BIAS)
|
adjustment == -RWSEM_ACTIVE_WRITE_BIAS)
|
||||||
sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED);
|
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 */
|
/* wait to be given the lock */
|
||||||
for (;;) {
|
for (;;) {
|
||||||
|
@ -245,13 +245,13 @@ struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
|
||||||
{
|
{
|
||||||
unsigned long flags;
|
unsigned long flags;
|
||||||
|
|
||||||
spin_lock_irqsave(&sem->wait_lock, flags);
|
raw_spin_lock_irqsave(&sem->wait_lock, flags);
|
||||||
|
|
||||||
/* do nothing if list empty */
|
/* do nothing if list empty */
|
||||||
if (!list_empty(&sem->wait_list))
|
if (!list_empty(&sem->wait_list))
|
||||||
sem = __rwsem_do_wake(sem, RWSEM_WAKE_ANY);
|
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;
|
return sem;
|
||||||
}
|
}
|
||||||
|
@ -265,13 +265,13 @@ struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
|
||||||
{
|
{
|
||||||
unsigned long flags;
|
unsigned long flags;
|
||||||
|
|
||||||
spin_lock_irqsave(&sem->wait_lock, flags);
|
raw_spin_lock_irqsave(&sem->wait_lock, flags);
|
||||||
|
|
||||||
/* do nothing if list empty */
|
/* do nothing if list empty */
|
||||||
if (!list_empty(&sem->wait_list))
|
if (!list_empty(&sem->wait_list))
|
||||||
sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED);
|
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;
|
return sem;
|
||||||
}
|
}
|
||||||
|
|
Загрузка…
Ссылка в новой задаче