{
unsigned long flags;
- spin_lock_irqsave(&task->pi_lock, flags);
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
__rt_mutex_adjust_prio(task);
- spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
}
/*
/*
* Task can not go away as we did a get_task() before !
*/
- spin_lock_irqsave(&task->pi_lock, flags);
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
waiter = task->pi_blocked_on;
/*
goto out_unlock_pi;
lock = waiter->lock;
- if (!spin_trylock(&lock->wait_lock)) {
- spin_unlock_irqrestore(&task->pi_lock, flags);
+ if (!raw_spin_trylock(&lock->wait_lock)) {
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
cpu_relax();
goto retry;
}
/* Deadlock detection */
if (lock == orig_lock || rt_mutex_owner(lock) == top_task) {
debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock);
- spin_unlock(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);
ret = deadlock_detect ? -EDEADLK : 0;
goto out_unlock_pi;
}
plist_add(&waiter->list_entry, &lock->wait_list);
/* Release the task */
- spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
put_task_struct(task);
/* Grab the next task */
task = rt_mutex_owner(lock);
get_task_struct(task);
- spin_lock_irqsave(&task->pi_lock, flags);
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
if (waiter == rt_mutex_top_waiter(lock)) {
/* Boost the owner */
__rt_mutex_adjust_prio(task);
}
- spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
top_waiter = rt_mutex_top_waiter(lock);
- spin_unlock(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);
if (!detect_deadlock && waiter != top_waiter)
goto out_put_task;
goto again;
out_unlock_pi:
- spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
out_put_task:
put_task_struct(task);
* assigned pending owner [which might not have taken the
* lock yet]:
*/
-static inline int try_to_steal_lock(struct rt_mutex *lock)
+static inline int try_to_steal_lock(struct rt_mutex *lock,
+ struct task_struct *task)
{
struct task_struct *pendowner = rt_mutex_owner(lock);
struct rt_mutex_waiter *next;
if (!rt_mutex_owner_pending(lock))
return 0;
- if (pendowner == current)
+ if (pendowner == task)
return 1;
- spin_lock_irqsave(&pendowner->pi_lock, flags);
- if (current->prio >= pendowner->prio) {
- spin_unlock_irqrestore(&pendowner->pi_lock, flags);
+ raw_spin_lock_irqsave(&pendowner->pi_lock, flags);
+ if (task->prio >= pendowner->prio) {
+ raw_spin_unlock_irqrestore(&pendowner->pi_lock, flags);
return 0;
}
* priority.
*/
if (likely(!rt_mutex_has_waiters(lock))) {
- spin_unlock_irqrestore(&pendowner->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&pendowner->pi_lock, flags);
return 1;
}
next = rt_mutex_top_waiter(lock);
plist_del(&next->pi_list_entry, &pendowner->pi_waiters);
__rt_mutex_adjust_prio(pendowner);
- spin_unlock_irqrestore(&pendowner->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&pendowner->pi_lock, flags);
/*
* We are going to steal the lock and a waiter was
* enqueued on the pending owners pi_waiters queue. So
* we have to enqueue this waiter into
- * current->pi_waiters list. This covers the case,
- * where current is boosted because it holds another
+ * task->pi_waiters list. This covers the case,
+ * where task is boosted because it holds another
* lock and gets unboosted because the booster is
* interrupted, so we would delay a waiter with higher
- * priority as current->normal_prio.
+ * priority as task->normal_prio.
*
* Note: in the rare case of a SCHED_OTHER task changing
* its priority and thus stealing the lock, next->task
- * might be current:
+ * might be task:
*/
- if (likely(next->task != current)) {
- spin_lock_irqsave(¤t->pi_lock, flags);
- plist_add(&next->pi_list_entry, ¤t->pi_waiters);
- __rt_mutex_adjust_prio(current);
- spin_unlock_irqrestore(¤t->pi_lock, flags);
+ if (likely(next->task != task)) {
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+ plist_add(&next->pi_list_entry, &task->pi_waiters);
+ __rt_mutex_adjust_prio(task);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
}
return 1;
}
*/
mark_rt_mutex_waiters(lock);
- if (rt_mutex_owner(lock) && !try_to_steal_lock(lock))
+ if (rt_mutex_owner(lock) && !try_to_steal_lock(lock, current))
return 0;
/* We got the lock. */
*/
static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
+ struct task_struct *task,
int detect_deadlock)
{
struct task_struct *owner = rt_mutex_owner(lock);
unsigned long flags;
int chain_walk = 0, res;
- spin_lock_irqsave(¤t->pi_lock, flags);
- __rt_mutex_adjust_prio(current);
- waiter->task = current;
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+ __rt_mutex_adjust_prio(task);
+ waiter->task = task;
waiter->lock = lock;
- plist_node_init(&waiter->list_entry, current->prio);
- plist_node_init(&waiter->pi_list_entry, current->prio);
+ plist_node_init(&waiter->list_entry, task->prio);
+ plist_node_init(&waiter->pi_list_entry, task->prio);
/* Get the top priority waiter on the lock */
if (rt_mutex_has_waiters(lock))
top_waiter = rt_mutex_top_waiter(lock);
plist_add(&waiter->list_entry, &lock->wait_list);
- current->pi_blocked_on = waiter;
+ task->pi_blocked_on = waiter;
- spin_unlock_irqrestore(¤t->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
if (waiter == rt_mutex_top_waiter(lock)) {
- spin_lock_irqsave(&owner->pi_lock, flags);
+ raw_spin_lock_irqsave(&owner->pi_lock, flags);
plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters);
plist_add(&waiter->pi_list_entry, &owner->pi_waiters);
__rt_mutex_adjust_prio(owner);
if (owner->pi_blocked_on)
chain_walk = 1;
- spin_unlock_irqrestore(&owner->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
}
else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock))
chain_walk = 1;
*/
get_task_struct(owner);
- spin_unlock(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);
res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter,
- current);
+ task);
- spin_lock(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);
return res;
}
struct task_struct *pendowner;
unsigned long flags;
- spin_lock_irqsave(¤t->pi_lock, flags);
+ raw_spin_lock_irqsave(¤t->pi_lock, flags);
waiter = rt_mutex_top_waiter(lock);
plist_del(&waiter->list_entry, &lock->wait_list);
rt_mutex_set_owner(lock, pendowner, RT_MUTEX_OWNER_PENDING);
- spin_unlock_irqrestore(¤t->pi_lock, flags);
+ raw_spin_unlock_irqrestore(¤t->pi_lock, flags);
/*
* Clear the pi_blocked_on variable and enqueue a possible
* waiter with higher priority than pending-owner->normal_prio
* is blocked on the unboosted (pending) owner.
*/
- spin_lock_irqsave(&pendowner->pi_lock, flags);
+ raw_spin_lock_irqsave(&pendowner->pi_lock, flags);
WARN_ON(!pendowner->pi_blocked_on);
WARN_ON(pendowner->pi_blocked_on != waiter);
next = rt_mutex_top_waiter(lock);
plist_add(&next->pi_list_entry, &pendowner->pi_waiters);
}
- spin_unlock_irqrestore(&pendowner->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&pendowner->pi_lock, flags);
wake_up_process(pendowner);
}
unsigned long flags;
int chain_walk = 0;
- spin_lock_irqsave(¤t->pi_lock, flags);
+ raw_spin_lock_irqsave(¤t->pi_lock, flags);
plist_del(&waiter->list_entry, &lock->wait_list);
waiter->task = NULL;
current->pi_blocked_on = NULL;
- spin_unlock_irqrestore(¤t->pi_lock, flags);
+ raw_spin_unlock_irqrestore(¤t->pi_lock, flags);
if (first && owner != current) {
- spin_lock_irqsave(&owner->pi_lock, flags);
+ raw_spin_lock_irqsave(&owner->pi_lock, flags);
plist_del(&waiter->pi_list_entry, &owner->pi_waiters);
if (owner->pi_blocked_on)
chain_walk = 1;
- spin_unlock_irqrestore(&owner->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
}
WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
/* gets dropped in rt_mutex_adjust_prio_chain()! */
get_task_struct(owner);
- spin_unlock(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);
rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current);
- spin_lock(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);
}
/*
struct rt_mutex_waiter *waiter;
unsigned long flags;
- spin_lock_irqsave(&task->pi_lock, flags);
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
waiter = task->pi_blocked_on;
if (!waiter || waiter->list_entry.prio == task->prio) {
- spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
return;
}
- spin_unlock_irqrestore(&task->pi_lock, flags);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
/* gets dropped in rt_mutex_adjust_prio_chain()! */
get_task_struct(task);
rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task);
}
-/*
- * Slow path lock function:
+/**
+ * __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop
+ * @lock: the rt_mutex to take
+ * @state: the state the task should block in (TASK_INTERRUPTIBLE
+ * or TASK_UNINTERRUPTIBLE)
+ * @timeout: the pre-initialized and started timer, or NULL for none
+ * @waiter: the pre-initialized rt_mutex_waiter
+ * @detect_deadlock: passed to task_blocks_on_rt_mutex
+ *
+ * lock->wait_lock must be held by the caller.
*/
static int __sched
-rt_mutex_slowlock(struct rt_mutex *lock, int state,
- struct hrtimer_sleeper *timeout,
- int detect_deadlock)
+__rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ struct rt_mutex_waiter *waiter,
+ int detect_deadlock)
{
- struct rt_mutex_waiter waiter;
int ret = 0;
- debug_rt_mutex_init_waiter(&waiter);
- waiter.task = NULL;
-
- spin_lock(&lock->wait_lock);
-
- /* Try to acquire the lock again: */
- if (try_to_take_rt_mutex(lock)) {
- spin_unlock(&lock->wait_lock);
- return 0;
- }
-
- set_current_state(state);
-
- /* Setup the timer, when timeout != NULL */
- if (unlikely(timeout)) {
- hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
- if (!hrtimer_active(&timeout->timer))
- timeout->task = NULL;
- }
-
for (;;) {
/* Try to acquire the lock: */
if (try_to_take_rt_mutex(lock))
}
/*
- * waiter.task is NULL the first time we come here and
+ * waiter->task is NULL the first time we come here and
* when we have been woken up by the previous owner
* but the lock got stolen by a higher prio task.
*/
- if (!waiter.task) {
- ret = task_blocks_on_rt_mutex(lock, &waiter,
+ if (!waiter->task) {
+ ret = task_blocks_on_rt_mutex(lock, waiter, current,
detect_deadlock);
/*
* If we got woken up by the owner then start loop
* all over without going into schedule to try
* to get the lock now:
*/
- if (unlikely(!waiter.task)) {
+ if (unlikely(!waiter->task)) {
/*
* Reset the return value. We might
* have returned with -EDEADLK and the
break;
}
- spin_unlock(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);
- debug_rt_mutex_print_deadlock(&waiter);
+ debug_rt_mutex_print_deadlock(waiter);
- if (waiter.task)
+ if (waiter->task)
schedule_rt_mutex(lock);
- spin_lock(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);
set_current_state(state);
}
+ return ret;
+}
+
+/*
+ * Slow path lock function:
+ */
+static int __sched
+rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ int detect_deadlock)
+{
+ struct rt_mutex_waiter waiter;
+ int ret = 0;
+
+ debug_rt_mutex_init_waiter(&waiter);
+ waiter.task = NULL;
+
+ raw_spin_lock(&lock->wait_lock);
+
+ /* Try to acquire the lock again: */
+ if (try_to_take_rt_mutex(lock)) {
+ raw_spin_unlock(&lock->wait_lock);
+ return 0;
+ }
+
+ set_current_state(state);
+
+ /* Setup the timer, when timeout != NULL */
+ if (unlikely(timeout)) {
+ hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
+ if (!hrtimer_active(&timeout->timer))
+ timeout->task = NULL;
+ }
+
+ ret = __rt_mutex_slowlock(lock, state, timeout, &waiter,
+ detect_deadlock);
+
set_current_state(TASK_RUNNING);
if (unlikely(waiter.task))
*/
fixup_rt_mutex_waiters(lock);
- spin_unlock(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);
/* Remove pending timer: */
if (unlikely(timeout))
{
int ret = 0;
- spin_lock(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);
if (likely(rt_mutex_owner(lock) != current)) {
fixup_rt_mutex_waiters(lock);
}
- spin_unlock(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);
return ret;
}
static void __sched
rt_mutex_slowunlock(struct rt_mutex *lock)
{
- spin_lock(&lock->wait_lock);
+ raw_spin_lock(&lock->wait_lock);
debug_rt_mutex_unlock(lock);
if (!rt_mutex_has_waiters(lock)) {
lock->owner = NULL;
- spin_unlock(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);
return;
}
wakeup_next_waiter(lock);
- spin_unlock(&lock->wait_lock);
+ raw_spin_unlock(&lock->wait_lock);
/* Undo pi boosting if necessary: */
rt_mutex_adjust_prio(current);
* Returns:
* 0 on success
* -EINTR when interrupted by a signal
- * -ETIMEOUT when the timeout expired
+ * -ETIMEDOUT when the timeout expired
* -EDEADLK when the lock would deadlock (when deadlock detection is on)
*/
int
void __rt_mutex_init(struct rt_mutex *lock, const char *name)
{
lock->owner = NULL;
- spin_lock_init(&lock->wait_lock);
- plist_head_init(&lock->wait_list, &lock->wait_lock);
+ raw_spin_lock_init(&lock->wait_lock);
+ plist_head_init_raw(&lock->wait_list, &lock->wait_lock);
debug_rt_mutex_init(lock, name);
}
}
/**
+ * rt_mutex_start_proxy_lock() - Start lock acquisition for another task
+ * @lock: the rt_mutex to take
+ * @waiter: the pre-initialized rt_mutex_waiter
+ * @task: the task to prepare
+ * @detect_deadlock: perform deadlock detection (1) or not (0)
+ *
+ * Returns:
+ * 0 - task blocked on lock
+ * 1 - acquired the lock for task, caller should wake it up
+ * <0 - error
+ *
+ * Special API call for FUTEX_REQUEUE_PI support.
+ */
+int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ struct task_struct *task, int detect_deadlock)
+{
+ int ret;
+
+ raw_spin_lock(&lock->wait_lock);
+
+ mark_rt_mutex_waiters(lock);
+
+ if (!rt_mutex_owner(lock) || try_to_steal_lock(lock, task)) {
+ /* We got the lock for task. */
+ debug_rt_mutex_lock(lock);
+ rt_mutex_set_owner(lock, task, 0);
+ raw_spin_unlock(&lock->wait_lock);
+ rt_mutex_deadlock_account_lock(lock, task);
+ return 1;
+ }
+
+ ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock);
+
+ if (ret && !waiter->task) {
+ /*
+ * Reset the return value. We might have
+ * returned with -EDEADLK and the owner
+ * released the lock while we were walking the
+ * pi chain. Let the waiter sort it out.
+ */
+ ret = 0;
+ }
+ raw_spin_unlock(&lock->wait_lock);
+
+ debug_rt_mutex_print_deadlock(waiter);
+
+ return ret;
+}
+
+/**
* rt_mutex_next_owner - return the next owner of the lock
*
* @lock: the rt lock query
return rt_mutex_top_waiter(lock)->task;
}
+
+/**
+ * rt_mutex_finish_proxy_lock() - Complete lock acquisition
+ * @lock: the rt_mutex we were woken on
+ * @to: the timeout, null if none. hrtimer should already have
+ * been started.
+ * @waiter: the pre-initialized rt_mutex_waiter
+ * @detect_deadlock: perform deadlock detection (1) or not (0)
+ *
+ * Complete the lock acquisition started our behalf by another thread.
+ *
+ * Returns:
+ * 0 - success
+ * <0 - error, one of -EINTR, -ETIMEDOUT, or -EDEADLK
+ *
+ * Special API call for PI-futex requeue support
+ */
+int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
+ struct hrtimer_sleeper *to,
+ struct rt_mutex_waiter *waiter,
+ int detect_deadlock)
+{
+ int ret;
+
+ raw_spin_lock(&lock->wait_lock);
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter,
+ detect_deadlock);
+
+ set_current_state(TASK_RUNNING);
+
+ if (unlikely(waiter->task))
+ remove_waiter(lock, waiter);
+
+ /*
+ * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might
+ * have to fix that up.
+ */
+ fixup_rt_mutex_waiters(lock);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ /*
+ * Readjust priority, when we did not get the lock. We might have been
+ * the pending owner and boosted. Since we did not take the lock, the
+ * PI boost has to go.
+ */
+ if (unlikely(ret))
+ rt_mutex_adjust_prio(current);
+
+ return ret;
+}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff