diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rtmutex.c | 51 |
1 files changed, 25 insertions, 26 deletions
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index 3e13a1e5856..4ab17da46fd 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -251,6 +251,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, /* Grab the next task */ task = rt_mutex_owner(lock); + get_task_struct(task); spin_lock_irqsave(&task->pi_lock, flags); if (waiter == rt_mutex_top_waiter(lock)) { @@ -269,7 +270,6 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, __rt_mutex_adjust_prio(task); } - get_task_struct(task); spin_unlock_irqrestore(&task->pi_lock, flags); top_waiter = rt_mutex_top_waiter(lock); @@ -409,7 +409,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, struct task_struct *owner = rt_mutex_owner(lock); struct rt_mutex_waiter *top_waiter = waiter; unsigned long flags; - int boost = 0, res; + int chain_walk = 0, res; spin_lock_irqsave(¤t->pi_lock, flags); __rt_mutex_adjust_prio(current); @@ -433,25 +433,23 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, plist_add(&waiter->pi_list_entry, &owner->pi_waiters); __rt_mutex_adjust_prio(owner); - if (owner->pi_blocked_on) { - boost = 1; - /* gets dropped in rt_mutex_adjust_prio_chain()! */ - get_task_struct(owner); - } - spin_unlock_irqrestore(&owner->pi_lock, flags); - } - else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock)) { - spin_lock_irqsave(&owner->pi_lock, flags); - if (owner->pi_blocked_on) { - boost = 1; - /* gets dropped in rt_mutex_adjust_prio_chain()! */ - get_task_struct(owner); - } + if (owner->pi_blocked_on) + chain_walk = 1; spin_unlock_irqrestore(&owner->pi_lock, flags); } - if (!boost) + else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock)) + chain_walk = 1; + + if (!chain_walk) return 0; + /* + * The owner can't disappear while holding a lock, + * so the owner struct is protected by wait_lock. + * Gets dropped in rt_mutex_adjust_prio_chain()! + */ + get_task_struct(owner); + spin_unlock(&lock->wait_lock); res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter, @@ -532,7 +530,7 @@ static void remove_waiter(struct rt_mutex *lock, int first = (waiter == rt_mutex_top_waiter(lock)); struct task_struct *owner = rt_mutex_owner(lock); unsigned long flags; - int boost = 0; + int chain_walk = 0; spin_lock_irqsave(¤t->pi_lock, flags); plist_del(&waiter->list_entry, &lock->wait_list); @@ -554,19 +552,20 @@ static void remove_waiter(struct rt_mutex *lock, } __rt_mutex_adjust_prio(owner); - if (owner->pi_blocked_on) { - boost = 1; - /* gets dropped in rt_mutex_adjust_prio_chain()! */ - get_task_struct(owner); - } + if (owner->pi_blocked_on) + chain_walk = 1; + spin_unlock_irqrestore(&owner->pi_lock, flags); } WARN_ON(!plist_node_empty(&waiter->pi_list_entry)); - if (!boost) + if (!chain_walk) return; + /* gets dropped in rt_mutex_adjust_prio_chain()! */ + get_task_struct(owner); + spin_unlock(&lock->wait_lock); rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current); @@ -592,10 +591,10 @@ void rt_mutex_adjust_pi(struct task_struct *task) return; } - /* gets dropped in rt_mutex_adjust_prio_chain()! */ - get_task_struct(task); 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); } |