diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/fork.c | 1 | ||||
| -rw-r--r-- | kernel/locking/rtmutex.c | 29 | ||||
| -rw-r--r-- | kernel/sched/core.c | 2 |
3 files changed, 24 insertions, 8 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 6c463c80e93d..b30196a00b0d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1438,6 +1438,7 @@ static void rt_mutex_init_task(struct task_struct *p) #ifdef CONFIG_RT_MUTEXES p->pi_waiters = RB_ROOT; p->pi_waiters_leftmost = NULL; + p->pi_top_task = NULL; p->pi_blocked_on = NULL; #endif } diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 71ecf0624410..bc05b104eaed 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -323,6 +323,19 @@ rt_mutex_dequeue_pi(struct task_struct *task, struct rt_mutex_waiter *waiter) } /* + * Must hold both p->pi_lock and task_rq(p)->lock. + */ +void rt_mutex_update_top_task(struct task_struct *p) +{ + if (!task_has_pi_waiters(p)) { + p->pi_top_task = NULL; + return; + } + + p->pi_top_task = task_top_pi_waiter(p)->task; +} + +/* * Calculate task priority from the waiter tree priority * * Return task->normal_prio when the waiter tree is empty or when @@ -337,12 +350,12 @@ int rt_mutex_getprio(struct task_struct *task) task->normal_prio); } +/* + * Must hold either p->pi_lock or task_rq(p)->lock. + */ struct task_struct *rt_mutex_get_top_task(struct task_struct *task) { - if (likely(!task_has_pi_waiters(task))) - return NULL; - - return task_top_pi_waiter(task)->task; + return task->pi_top_task; } /* @@ -351,12 +364,12 @@ struct task_struct *rt_mutex_get_top_task(struct task_struct *task) */ int rt_mutex_get_effective_prio(struct task_struct *task, int newprio) { - if (!task_has_pi_waiters(task)) + struct task_struct *top_task = rt_mutex_get_top_task(task); + + if (!top_task) return newprio; - if (task_top_pi_waiter(task)->task->prio <= newprio) - return task_top_pi_waiter(task)->task->prio; - return newprio; + return min(top_task->prio, newprio); } /* diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ab9f6ac099a7..e1f44ec701c8 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3713,6 +3713,8 @@ void rt_mutex_setprio(struct task_struct *p, int prio) goto out_unlock; } + rt_mutex_update_top_task(p); + trace_sched_pi_setprio(p, prio); oldprio = p->prio; |