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Diffstat (limited to 'kernel/rtmutex.c')
-rw-r--r--kernel/rtmutex.c42
1 files changed, 36 insertions, 6 deletions
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 3fc0f0680ca2..45d61016da57 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -160,7 +160,8 @@ int max_lock_depth = 1024;
static int rt_mutex_adjust_prio_chain(task_t *task,
int deadlock_detect,
struct rt_mutex *orig_lock,
- struct rt_mutex_waiter *orig_waiter
+ struct rt_mutex_waiter *orig_waiter,
+ struct task_struct *top_task
__IP_DECL__)
{
struct rt_mutex *lock;
@@ -189,7 +190,7 @@ static int rt_mutex_adjust_prio_chain(task_t *task,
prev_max = max_lock_depth;
printk(KERN_WARNING "Maximum lock depth %d reached "
"task: %s (%d)\n", max_lock_depth,
- current->comm, current->pid);
+ top_task->comm, top_task->pid);
}
put_task_struct(task);
@@ -229,7 +230,7 @@ static int rt_mutex_adjust_prio_chain(task_t *task,
}
/* Deadlock detection */
- if (lock == orig_lock || rt_mutex_owner(lock) == current) {
+ if (lock == orig_lock || rt_mutex_owner(lock) == top_task) {
debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock);
spin_unlock(&lock->wait_lock);
ret = deadlock_detect ? -EDEADLK : 0;
@@ -433,6 +434,7 @@ static int task_blocks_on_rt_mutex(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);
}
spin_unlock_irqrestore(&owner->pi_lock, flags);
@@ -441,6 +443,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
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);
}
spin_unlock_irqrestore(&owner->pi_lock, flags);
@@ -450,8 +453,8 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
spin_unlock(&lock->wait_lock);
- res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock,
- waiter __IP__);
+ res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter,
+ current __IP__);
spin_lock(&lock->wait_lock);
@@ -552,6 +555,7 @@ static void remove_waiter(struct rt_mutex *lock,
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);
@@ -564,12 +568,37 @@ static void remove_waiter(struct rt_mutex *lock,
spin_unlock(&lock->wait_lock);
- rt_mutex_adjust_prio_chain(owner, 0, lock, NULL __IP__);
+ rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current __IP__);
spin_lock(&lock->wait_lock);
}
/*
+ * Recheck the pi chain, in case we got a priority setting
+ *
+ * Called from sched_setscheduler
+ */
+void rt_mutex_adjust_pi(struct task_struct *task)
+{
+ struct rt_mutex_waiter *waiter;
+ unsigned long flags;
+
+ 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);
+ return;
+ }
+
+ /* gets dropped in rt_mutex_adjust_prio_chain()! */
+ get_task_struct(task);
+ spin_unlock_irqrestore(&task->pi_lock, flags);
+
+ rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task __RET_IP__);
+}
+
+/*
* Slow path lock function:
*/
static int __sched
@@ -636,6 +665,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
if (unlikely(ret))
break;
}
+
spin_unlock(&lock->wait_lock);
debug_rt_mutex_print_deadlock(&waiter);

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