Merge git://oss.sgi.com:8090/nathans/xfs-2.6

[firefly-linux-kernel-4.4.55.git] / kernel / rtmutex.c

diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 3fc0f0680ca267fe5d43c7a3f258c920122df239..45d61016da57612ec7690568abaef95a4515c547 100644 (file)
--- 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);
@@ -564,11 +568,36 @@ 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:
  */
@@ -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);