diff options
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | kernel/rtmutex.c | 42 | ||||
| -rw-r--r-- | kernel/sched.c | 2 |
3 files changed, 40 insertions, 6 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index b4e6be7de5ad..821f0481ebe1 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1044,11 +1044,13 @@ extern void sched_idle_next(void); #ifdef CONFIG_RT_MUTEXES extern int rt_mutex_getprio(task_t *p); extern void rt_mutex_setprio(task_t *p, int prio); +extern void rt_mutex_adjust_pi(task_t *p); #else static inline int rt_mutex_getprio(task_t *p) { return p->normal_prio; } +# define rt_mutex_adjust_pi(p) do { } while (0) #endif extern void set_user_nice(task_t *p, long nice); 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); diff --git a/kernel/sched.c b/kernel/sched.c index 7a30addfd235..2629c1711fd6 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4070,6 +4070,8 @@ recheck: __task_rq_unlock(rq); spin_unlock_irqrestore(&p->pi_lock, flags); + rt_mutex_adjust_pi(p); + return 0; } EXPORT_SYMBOL_GPL(sched_setscheduler); |